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CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application claims priority under 35 U.S.C. §119(e) from U.S. Provisional Patent Application Ser. No. 61/112,213, filed Nov. 7, 2008, entitled “THERMOSETTING POWDER ADHESIVE COMPOSITION”, and U.S. Provisional Patent Application Ser. No. 61/112,223, filed Nov. 7, 2008, entitled “STABLE POWDER ADHESIVE”, the disclosures of which are incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to powder adhesive compositions particularly useful for bonding rubber to metal. More particularly, the present invention relates to powdered adhesives which form thermoset films upon heating to bond vulcanizable elastomers to metallic substrates. BACKGROUND OF THE INVENTION [0003] Rubber-to-metal adhesion is necessary in order to make many of the rubber products we rely upon today including tires, mounts, bushings and some types of seals. Historically, this has been accomplished through making the rubber compounds self-bonding to brass plated steel or through the use of solvent or aqueous based primers with solvent or aqueous based adhesive covercoats. [0004] Powder rubber to substrate adhesives have recently been developed as discussed in U.S. patent application Ser. No. 12/126,175, filed May 23, 2008, entitled “POWDER ADHESIVES FOR BONDING ELASTOMERS”, herein incorporated by reference in full. While these are environmentally preferred to solvent or aqueous adhesives, they suffer from some problems not encountered with the prior technologies. Specifically, powder adhesives are more prone to “sweep” when an elastomer is injected into a mold cavity containing a powder coated part. The incoming rubber sweeps the powder adhesive from the part, even if the powder adhesive has been sintered prior to molding. [0005] Bonding of rubber vulcanizates to substrates, especially metal is conventionally obtained by two-coat primer-overcoat adhesive systems or one-coat primerless systems. Adhesive composition must exhibit excellent bonding, demonstrated as retention of rubber on the substrate after bond destruction. Further, when employed in a rubber molding operation, the adhesive must exhibit good sweep resistance. Sweep resistance is regarded as the ability of the uncured adhesive coating on the substrate to remain undisturbed against the force of injected green rubber into the mold cavity. [0006] Sweep resistance is particularly difficult to achieve when a powder adhesive is employed. The sweep resistance of a powder adhesive is improved somewhat by heating the coated part to sinter the powder adhesive prior to the molding operation. However, a sintered powder adhesive still often lacks the level of sweep resistance required for many rubber molding/bonding operations. During the heated molding/bonding operation, the sintered adhesive could melt and is therefore prone to sweep as liquid rubber enters the mold. [0007] It would therefore be desirable to provide a powder adhesive that possesses adequate sweep resistance for rubber molding/bonding operations. SUMMARY OF THE INVENTION [0008] In a first aspect of the present invention, a powder adhesive is provided comprising a primary rubber bonding polymer and a thermosetting component. By adding a thermosetting component to a powdered adhesive, the adhesive may be applied to a substrate, sintered and thermoset to provide a sweep resistant adhesive film on the substrate, which may subsequently be bonded to an elastomer. Without a thermosetting component, the adhesive is at risk to re-melt or otherwise soften during a heated elastomer molding operation which in turn could cause the adhesive material to sweep off the substrate. [0009] Thus, an adhesive for bonding metal to elastomers is provided which does not employ solvents and as such is delivered to a substrate substantially free of water or other liquids, while maintaining sweep resistance and forming environmentally durable bonds. Further, the powder adhesive compositions of the present invention comprise materials which are shelf stable and do not sinter nor alter their bonding properties during storage, yet can flow sufficiently to be sprayable and are sinterable at higher temperatures. [0010] One advantage of powdered (dry) adhesives is the ability to mix materials that are incompatible in solvent or aqueous forms. Powder technology allows mixtures of otherwise incompatible materials to be partitioned from each other as separate powders and the different powders can be mixed together in dry blends. They remain compatible and/or non-reactive until the composition is heated at which time the components melt and merge together. [0011] Using this technique, the embodiments of the present invention provide mixtures of powder adhesives containing a thermosetting component which remains unreactive until the powder adhesive is sintered, and the thermosetting component reacts to form a thermoset film and adhere the adhesive to a substrate so as to render the thermoset adhesive sweep resistant and stable. [0012] In a first aspect of the present invention, a powder adhesive composition comprising a sinterable primary rubber bonding polymer and a thermosetting compound, wherein upon heating the primary rubber bonding polymer will be stabilized in a thermoset film and wherein the thermosetting compound comprises either: (1) a cure agent which will at least partially cure the primary rubber bonding polymer to form said thermoset film; or, (2) a separate thermosetting composition which will entrap the primary rubber bonding polymer in said thermoset film. [0013] In one embodiment of the present invention, the rubber bonding polymer comprises a sinterable dichlorobutadiene alpha-bromoacrylonitrile copolymer powder. In a further embodiment of the present invention, the cure agent comprises at least one of an organic peroxide, a thiourea, or a sulfur curative. In a still further embodiment of the present invention, the thermosetting compound comprises a phenolic resin and phenolic curative. An in yet another embodiment of the present invention, the cure system comprises from 0.5% to 15% of the composition and is capable of crosslinking the sinterable primary rubber bonding polymer. [0014] In another embodiment of the present invention, the separate thermosetting composition comprises chlorosulfonated polyethylene and a crosslinker capable of crosslinking the chlorosulfonated polyethylene. In a preferred embodiment of the present invention, the crosslinker comprises poly-dinitrosobenzene. In a most preferred embodiment of the present invention, the composition comprises 1 to 25 weight percent chlorosulfonated polyethylene, and 1 to 25 weight percent poly-dinitrosobenzene. [0015] In an additional embodiment of the present invention, the adhesive composition further comprises from 1 to 30 weight percent of a filler, and preferably the filler comprises carbon black. [0016] In another aspect of the present invention, a method for reducing sweep in a powder adhesive is provided comprising, (a) providing a sinterable primary rubber bonding polymer, (b) providing a thermosetting compound, (c) mixing the rubber bonding polymer and thermosetting compound together in powder form to provide a powder adhesive composition, (d) applying the powder adhesive composition to a substrate to at least partially coat the substrate with powder adhesive, and (e) heating the coated substrate to sinter and thermoset the powder adhesive composition. [0017] In another embodiment of the present invention, the thermosetting compound comprises either (1) a cure agent which will at least partially cure the primary rubber bonding polymer, or (2) a separate thermosetting composition which will entrap the primary rubber bonding polymer in a thermoset film. [0018] In yet another embodiment of the present invention, the primary rubber bonding polymer comprises a sinterable dichlorobutadiene alpha-bromoacrylonitrile copolymer powder, and the cure agent comprises at least one of an organic peroxide, a thiourea, or a sulfur curative. DETAILED DESCRIPTION OF THE INVENTION [0019] In one embodiment of the present invention, the powder adhesive comprises a sinterable primary rubber bonding polymer powder. To this powder adhesive composition a thermosetting compound is added comprising (1) a cure agent which will at least partially cure the primary rubber bonding polymer, or (2) a separate thermosetting composition which entraps the rubber bonding polymer in a thermoset film. [0020] In another embodiment of the present invention, the sinterable primary rubber bonding polymer comprises a halogen-containing polyolefin. The halogens employed in the halogenated polyolefinic elastomers will usually be chlorine or bromine, although fluorine can also be used. Mixed halogens can also be employed in which case the halogen-containing polyolefinic elastomer will have more than one halogen substituted thereon. Halogen-containing polyolefinic elastomers and their preparation are well-known in the art and no need is seen to elucidate in any detail on these materials or their manufacture. [0021] Representative halogenated polyolefins include chlorinated natural rubber, chlorine- and bromine-containing synthetic rubbers including polychloroprene, chlorinated polychloroprene, chlorinated polybutadiene, hexachloropentadiene, butadiene/halogenated cyclic conjugated diene adducts, chlorinated butadiene styrene copolymers, chlorinated ethylene propylene copolymers and ethylene/propylene/non-conjugated diene terpolymers, chlorinated polyethylene, chlorosulfonated polyethylene, poly(2,3-dichloro-1,3-butadiene), brominated poly(2,3-dichloro-1,3-butadiene), copolymers of α-haloacrylonitriles and 2,3-dichloro-1,3-butadiene, chlorinated poly(vinyl chloride) and the like including mixtures of such halogen-containing elastomers. [0022] The butadiene monomers useful for preparing the butadiene polymer can essentially be any monomer containing conjugated unsaturation. Typical monomers include 2,3-dichloro-1,3-butadiene; 1,3-butadiene; 2,3-dibromo-1,3-butadiene isoprene; isoprene; 2,3-dimethylbutadiene; chloroprene; bromoprene; 2,3-dibromo-1,3-butadiene; 1,1,2-trichlorobutadiene; cyanoprene; hexachlorobutadiene; and combinations thereof. It is particularly preferred to use 2,3-dichloro-1,3-butadiene since a polymer that contains as its major portion 2,3-dichloro-1,3-butadiene monomer units has been found to be particularly useful in adhesive applications due to the excellent bonding ability and barrier properties of the 2,3-dichloro-1,3-butadiene-based polymers. As described above, an especially preferred embodiment of the present invention is one wherein the butadiene polymer includes at least 60 weight percent, preferably at least 70 weight percent, 2,3-dichloro-1,3-butadiene monomer units. [0023] The butadiene monomer can be copolymerized with other monomers. Such copolymerizable monomers include α-haloacrylonitriles such as α-bromoacrylonitrile and α-chloroacrylonitrile; α,β-unsaturated carboxylic acids such as acrylic, methacrylic, 2-ethylacrylic, 2-propylacrylic, 2-butylacrylic and itaconic acids; alkyl-2-haloacrylates such as ethyl-2-chloroacrylate and ethyl-2-bromoacrylate; α-bromovinylketone; vinylidene chloride; vinyl toluenes; vinylnaphthalenes; vinyl ethers, esters and ketones such as methyl vinyl ether, vinyl acetate and methyl vinyl ketone; esters amides, and nitriles of acrylic and methacrylic acids such as ethyl acrylate, methyl methacrylate, glycidyl acrylate, methacrylamide and acrylonitrile; and combinations of such monomers. The copolymerizable monomers, if utilized, are preferably α-haloacrylonitrile and/or α, β-unsaturated carboxylic acids. The copolymerizable monomers may be utilized in an amount of 0.1 to 30 weight percent, based on the weight of the total monomers utilized to form the butadiene polymer. [0024] In a preferred embodiment of the present invention, the rubber bonding polymer comprises a copolymer of dichlorobutadiene and brominated acrylonitrile (DCD/α-BrAN). Copolymer of DCD/α-BrAN are known to be effective for bonding rubber to metal in the range of 95:5 to 85:15. However, used alone DCD/α-BrAN is prone to sweep because no reaction occurs during the sintering process to make it thermosetting. The addition of another thermosetting component such as a powdered phenolic composition or a material (either melting or non-melting) containing a curing or crosslinking agent can be dry blended with the powdered DCD/α-BrAN to render it thermosetting during the sintering process and keep it from sweeping off of the metal. [0025] In one embodiment of the present invention, the thermosetting component comprises a curing agent added to the rubber bonding polymer to at least partially cure and thermoset the rubber bonding polymer. In a preferred embodiment of the present invention, wherein rubber bonding polymer comprises a DCD/α-BrAN copolymer and the curing agent comprises at least one of an organic peroxide, a thiourea, or a sulfur cure system such as tetramethylthiuram disulfide. The curing agent at least partially cures and thermosets the DCD/α-BrAN during the powder sintering process to improve sweep resistance of the adhesive. [0026] In a most preferred embodiment of the present invention, the curing agent comprises at least one of the following: organic peroxides (generally di-tertiary alkyl peroxides) including but not limited to 2,5-dimethyl-2,5-di(t-butylperoxy) hexane, 2,5-dimethyl-2,5-di(t-butylperoxy) hexyne-3, dicumyl peroxide, t-butyl cumyl peroxide and α,α′-di(2-t-butylperoxyisopropyl) benzene; thioureas including but not limited to 1,3-dibutylthiourea, trimethylthiourea, 1,3-diethylthiourea, and ethylenethiourea; and, sulfur donors including but not limited to tetramethylthiuram disulfide, tetraethylthiuram disulfide, dipentamethylenethiuram tetrasulfide or hexasulfide, or elemental sulfur combined with traditional sulfur accelerators known to the rubber industry. [0027] In another embodiment of the present invention, the primary rubber bonding polymer is not provided with a cure agent, but rather a separate thermosetting composition is added to the primary rubber bonding polymer to provide a thermosetting film upon cure which entraps and stabilizes the primary rubber bonding polymer in a thermoset film. The thermosetting composition is preferably compatible with the primary adhesive constituents so as to provide good mixing and adhesive film formation. Further, the thermosetting composition is preferably absent internal or pendant unsaturation so as to prevent curing while the components are mixed in powdered form. In a preferred embodiment of the present invention, the cure is not initiated until the mixture is heated during a sintering step. [0028] In a further embodiment of the present invention, a rubber bonding polymer such as a halogenated polybutadiene is employed as the primary rubber bonding polymer, and a second thermosetting composition comprising chlorosulfonated polyethylene and a curative such as poly-dinitrosobenzene (DNB) are provided to affect a thermoset film upon heating. The chlorosulfonated polyethylene and DNB will react to form a thermoset film which entraps and stabilized the primary rubber bonding polymer. Additionally, since chlorosulfonated polyethylene and DNB are preferred rubber adhesive components, they are particularly well suited for use in the present invention. The addition of a minor percentage of chlorosulfonated polyethylene into a polybutadiene based formulation along with DNB makes the composition thermosetting. In addition to chlorosulfonated polyethylene, other thermosetting polymer compounds suitable for use in the present invention include polychloroprene and chlorinated polyethylene. [0029] In another aspect of the invention, it has also been discovered that addition of particular reinforcing fillers to the rubber bonding polymer improves its sweep resistance. A reinforcing filler increases the viscosity, which improves sweep resistance and it also reinforces the polymer, thus improving the strength, especially at high temperatures. [0030] In a preferred embodiment of the present invention, the reinforcing filler comprises a nano-scale particulate reinforcing filler such as carbon black, precipitated or fumed silicas, fumed metal oxides such as zinc oxide, or silicates such as calcium silicate. These materials increase the strength of vulcanized rubber compounds and are shown here to be useful in increasing the hot tear strength of the adhesive composition. In an embodiment of the present invention, the filler is present in an amount from 1 to 30 weight percent. Other suitable fillers comprise particulate fillers that have a primarily particle size of less than about 200 nanometers. [0031] It is also to be understood that the phraseology and terminology herein are for the purposes of description and should not be regarded as limiting in any respect. Those skilled in the art will appreciate the concepts upon which this disclosure is based and that it may readily be utilized as the basis for designating other structures, methods and systems for carrying out the several purposes of this development. It is important that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. [0032] Although the present invention has been described with reference to particular embodiments, it should be recognized that these embodiments are merely illustrative of the principles of the present invention. Those of ordinary skill in the art will appreciate that the compositions, apparatus and methods of the present invention may be constructed and implemented in other ways and embodiments. Accordingly, the description herein should not be read as limiting the present invention, as other embodiments also fall within the scope of the present invention as defined by the appended claims. EXAMPLES [0033] Covercoat A is adhesive topcoat composition containing poly-dinitrosobenzene (DNB) and other fillers in post-brominated polydichlorobutadiene. When dried and ground Covercoat A is non-sintering and therefore does not withstand sweep when employed in a mold as a powdered adhesive composition. [0034] Primer A is a thermosetting blend of acrylonitrile butadiene rubber with phenolic resins and curatives for the phenolic resins. The curatives are methylene donors, in this case, a blend of hexamethylenetetramine (HMT) and hexamethoxymethylmelamine (HMMM). [0035] The topcoat compositions in Examples 1 to 3 were bonded to zinc phosphatized steel (ZPS) coupons. Powder Primer A was applied and sintered 5 minutes at 320° F. The topcoat was sintered 7 minutes at 320° F. A sulfur-cured carbon-black reinforced natural rubber compound (HC130) was bonded in an injection mold at 300° F. Examples 1 to 3 of Dry-Blended Powders [0036] [0000] Example (dry blends) Control 1 Dry blend 2 Dry blend 3 DCD/α-BrAN 100.0 75.0 80.0 Primer A — 25.0 — Covercoat A — — 20.0 Primer Thickness 2.6 1.9 1.9 Total Film Thickness (mils) 3.0 2.8 3.1 Sweep Significant None None Hot Tear Fair Fair Good Primary Bond (pounds) 49 52 59 Boiling Water resistance <9 min. >4 hrs >24 hrs Examples 4 to 6 of Dry-Blended Powders [0037] In another example, a chlorinated polypropylene (CPP) topcoat containing 10% DNB was blended with a dichlorobutadiene-alpha-bromoacrylonitrile-hydroxyethylacrylate (DCD/α-BrAN-HEA) terpolymer (90:8:2) to make a topcoat with better performance than either material separately. [0038] Examples 4 to 6 were bonded to zinc phosphatized steel (ZPS) coupons. Powder Primer A was applied and sintered 5 minutes at 320° F. The topcoat was sintered 7 minutes at 320° F. A sulfur-cured carbon-black reinforced natural rubber compound (HC130) was bonded in an injection mold at 300° F. [0000] Example (dry blends) Control 4 Control 5 Dry blend 6 DCD/α-BrAN-HEA 100.0 — 50.0 CPP composition — 100.0 50.0 Film formation Excellent Poor Good Sweep Significant None None Hot Tear Fair Good Good Primary Bond (pounds) 66 58 63 Boiling Water resistance >4 hrs <2 min. >16 hrs Examples 7 to 11 of Dry-Blended Powders [0039] The different powders can be blended across a fairly broad range as demonstrated by the topcoats in Examples 7-11. At higher levels of phenolic primer, the blend can be used as a single coat system rather than the traditional two coat primer/adhesive systems. [0000] Example (dry blends) 7 8 9 10 11 DCD/α-BrAN 75.0 65.0 55.0 45.0 35.0 Primer A 25.0 35.0 45.0 55.0 65.0 [0040] The following data was generated with zinc phosphatized steel (ZPS) coupons. Powder Primer A was applied and sintered 5 minutes at 320° F. The topcoat was sintered 7 minutes at 320° F. A sulfur-cured carbon-black reinforced natural rubber compound (HC130) was bonded in an injection mold at 300° F. [0000] Example (dry blends) 7 8 9 10 11 Total Film Thickness (mils) 2.4 2.9 2.7 3.3 3.6 Primary Bond (pounds) 52 52 49 44 30 [0041] The following was bonded to zinc phosphatized steel (ZPS) coupons without the use of a primer. The topcoat was sintered 7 minutes at 320° F. A sulfur-cured carbon-black reinforced natural rubber compound (HC130) was bonded in an injection mold at 300° F. [0000] Example (dry blends) 7 8 9 10 11 Total Film Thickness (mils) 1.2 1.3 1.8 2.3 2.2 Primary Bond (pounds) 31 40 49 46 27 [0042] In Examples 13-17 the addition of both a curative for the rubber bonding polymer and a carbon black filler (example 17) provide superior performance over compositions containing only filler (13) or only a curative (14-16). [0000] 12 13 14 15 16 17 DCD/α-BrAN 100.0 85.0 95.0 97.0 95.0 80.0 N234 carbon black — 15.0 — — — 15.0 DBPH* — — 5.0 — — 5.0 DBTU* — — — 3.0 — — TMTD* — — — — 5.0 — MDR 2000 rheometer tested 15 minutes at 320° F. Low torque (lb-in) 0.06 0.39 0.08 0.11 0.03 0.28 High torque (lb-in) 0.26 0.70 8.04 3.90 3.89 23.94 Primary bond strength (lbs) 71 70 61 65 60 77 Boiling water resistance >4 hrs >4 hrs >4 hrs >4 hrs >4 hrs >24 hrs Hot Tear resistance poor fair fair fair fair excellent % rubber tear 0 5 5 5 5 80 Sweep resistance poor fair good good good no sweep *DBPH: 50% active 2,5-dimethyl-2,5-di(t-butylperoxy) hexane *DBTU: 1,3-dibutylthiourea *TMTD: tetramethylthiuram disulfide [0043] Similarly, in Examples 18-22 secondary thermosetting components (DNB and CSPE), are provided in place of a curative for the primary rubber bonding polymer (DCD/α-BrAN). [0000] 18 19 20 21 22 DCD/α-BrAN 100.0 90.0 85.0 60.0 65.0 DNB — 10.0 — 10.0 10.0 Carbon Black — — 15.0 15.0 — Chlorosulfonated — — — 15.0 15.0 polyethylene SiO 2 (powder) — — — — 10.0 MDR 2000 rheometer tested 15 minutes at 320° F. Low torque (lb-in) 0.06 0.03 0.39 0.76 0.28 High torque (lb-in) 0.26 0.62 0.70 16.73 7.16 Hot Tear resistance poor poor fair Excellent Excellent % rubber tear 0 0 5 rubber break rubber break Sweep resistance poor poor fair no sweep no sweep

A powder adhesive comprising a primary rubber bonding polymer and a thermosetting component, and a method for bonding elastomers to metals employing the same. By adding a thermosetting component to a powdered adhesive, the adhesive may be applied to a substrate, sintered and thermoset to provide a sweep resistant adhesive film on the substrate, which may subsequently be bonded to an elastomer. Without a thermosetting component, the adhesive is at risk to re-melt or otherwise soften during a heated elastomer molding operation which in turn could cause the adhesive material to sweep off the substrate.

CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit of provisional patent application serial No. 60/143,056, entitled “COMPUTERIZED SYSTEM AND METHOD FOR ASSISTING POTENTIAL CLIENTS TO IDENTIFY AN APPROPRIATE PROVIDER FOR PROFESSIONAL SERVICES” filed on Jul. 9, 1999, the entirety of which is hereby incorporated by reference. FIELD OF INVENTION The present invention relates generally to techniques for providing professional services, and more particularly to a computerized method for matching potential clients with organizations which meet their personalized criteria and are interested in providing particular services to them. BACKGROUND OF THE INVENTION Often finding a service provider that meets ones criteria is a difficult and daunting task. For example, it can often be challenging for a potential client to find an attorney who is both skilled in a pertinent area of law and willing to undertake a specific task or case. Often, time is wasted interviewing firms that either lack the necessary expertise or are unwilling to take on a particular case for any of a number of reasons. Quite understandably, the same difficulty presents itself in many other fields, both professional and trade-related in nature for example. Similarly, it can often be difficult for a provider of services, a law firm for example, to easily identify potential clients who have a matter which the particular service provider is both capable and willing to undertake. Accordingly, it is highly desirable and an object of the present invention to provide a method, and system for implementing it, capable of aiding the matching of a service provider capable and willing to consider performing a specific task with a potential client for a particular matter. SUMMARY OF THE INVENTION A computerized method for matching potential clients with professional services providers which meet their personalized criteria and are interested in providing particular services to them including the steps of: presenting a first electronic document including a plurality of data entry devices to the potential clients via a computer network; receiving data entered using the data entry devices, the received data being indicative of the criteria; automatically comparing the received data to data stored in a storage medium to identify one or more suitable professional services providers; automatically generating and transmitting via the computerized network an electronic mail message to the identified one or more service providers, the electronic message including information indicative of a portion of the received data; and, receiving a response from at least one responding one of the one or more identified service providers, and automatically providing information indicative of another portion of the received data to the responding one of the service providers. BRIEF DESCRIPTION OF THE FIGURES Various objects, features and advantages of the invention will become more apparent by reading the following detailed description in conjunction with the drawings, which are shown by way of example only, wherein: FIGS. 1A-1C illustrate a sequence of operations according to a preferred embodiment of the invention; FIG. 2 illustrates a first computer page displayed according to a preferred embodiment of the present invention; FIG. 3 illustrates a second computer page displayed according to a preferred embodiment of the present invention; FIG. 4 illustrates a third computer page displayed according to a preferred embodiment of the present invention; FIG. 5 illustrates an exemplary e-mail generated according to a preferred embodiment of the present invention; FIG. 6 illustrates a fourth computer page displayed according to a preferred embodiment of the present invention; FIG. 7 illustrates a fifth computer page displayed according to a preferred embodiment of the present invention; FIGS. 8 a and 8 b illustrate a flow diagram of the preferred form of the invention for entering a new case; DETAILED DESCRIPTION OF THE INVENTION It should be understood that while the following discussion and the figures illustrate and explain the present invention as it relates to legal services, the present invention is equally applicable to a number of other businesses and service industries as well, and the selection of legal services has only been made for purposes of clarifying the explanation. Referring now to the figures wherein like references refer to like elements of the invention, FIG. 1A illustrates a first portion of a preferred sequence of operations according to a preferred embodiment of the invention. Preferably, the system according to the present invention is accessible through the global interconnection of computers and computer networks commonly referred to as the “Internet”. A potential client first accesses 10 the internet using any conventional means, e.g. a personal computer having a modem coupled to an Internet service provider using a standard phone line. Once connected, the potential client preferably accesses 20 a web page 30 which preferably prompts the potential client to enter a new service request using an Internet browser, such as Netscape Navigator or Microsoft Internet Explore for example, which is run on the potential client's Personal Computer (PC) or other suitable microprocessor based device. Referring now also to FIG. 2, therein is illustrated a preferred form of web page 30 which includes hypertext markup language (“HTML”) links 40 and 50 . Link 40 , upon activation by the potential client (for example by clicking on it with a mouse connected to the potential client's PC), preferably enables a user to enter 60 a new matter request by forwarding the potential client to web page 70 which is adapted to enable the potential client to enter 80 information regarding the service being requested (see FIG. 3 also). Link 50 , upon similar activation by the potential client to access a web page adapted to enable a user to delete a new matter request he previously entered. Referring again to FIG. 3, therein is illustrated the specific instance of a web page 70 adapted to enable the potential client to enter information regarding a legal matter which the potential user would like to retain a law firm to represent him in regards to. It should of course be recognized however, that the present invention is equally applicable to other services and types of professional service providers as well though. Web page 70 preferably first includes instructions 90 for guiding a potential client through utilizing the present invention. As set forth, the web page 70 is preferably adapted to enable the potential client to enter 80 information is about the matter with which he is seeking legal assistance. To this end, web page 70 preferably includes data devices 100 - 200 . List 100 includes all jurisdictions which any law firms which is a member of the system according to the present invention may practice in. In other words, all geographic locations where law firms which may be selected can be found. List 110 preferably provides, for selection, areas of specialization of law firms which can be contacted according to the present invention. Drop list 120 preferably allows the potential client to select the approximate size of the a law firm which he would like to engage. Window 130 preferably enables the potential client to provide a brief description of, and general information regarding the matter which he is seeking legal assistance. Similarly, window 140 preferably allows the potential client to enter some comments regarding the legal matter with which he is seeking legal assistance. Window 150 permits the potential client to enter an approximate budget for the legal matter and windows 160 , 170 , 180 , and 190 allow the potential client to enter their name and contact information. Finally, button 200 provides a means for a client to submit the information entered 80 , and hence the new matter request, to the system according to the present invention for distribution to appropriate member law firms and member attorneys for their consideration. Upon activation of the submit button 200 , the system according to a preferred embodiment of the present invention preferably checks the data which has entered 80 using the data devices 100 - 190 to determine if proper information has been entered. For example, the system preferably checks to see if selections were made using lists 90 , 100 , and 110 , and whether information was entered using windows 130 , 140 , 150 , 160 , 170 , 180 , and 190 . Further, the system preferably checks the form of the data entered using windows 180 and 190 to determine at least whether the entered e-mail address and telephone number appear to be in a proper format (e.g., xxx@xxx.xxx and xxx-xxx-xxxx). If the system determines improper information was entered, or data is missing, the system preferably prompts the potential client to either correct the improper data or enter missing data. Referring now also to FIG. 1B, after the system has verified that the information entered 80 at least appears valid, the system according to the present invention preferably generates 210 a unique, or at least substantially unique matter ID 220 and password 230 to respectively identify and permit access to the entered information. All of this data entered 80 , unique matter identification 220 and password 230 are then recorded 250 as a record into a database. Referring now also to FIG. 4, upon successful recordation 250 , the system preferably generates a web page 240 for display to the potential client. Accordingly, the potential client receives a verification that his new matter has been entered into the system, and is provided the ID 220 and password so that the matter may be deleted or modified. Referring again to FIG. 1B, at predetermined time intervals, or periods, a database query is preferably performed 260 to identify member law firms which satisfy the new matter requests which have been entered by potential clients. Preferably this occurs twice a day for example, although the selection of this time interval should depend upon the amount of new matter requests which are entered (i.e. more requests=a shorter interval between queries). Member law firms, and member individual attorneys, are preferably signed up with the system according to the preferred embodiment of the present system invention for a membership fee. When law firms and attorneys are signed as members they preferably provide similar information about themselves as was entered 80 by the potential clients, e.g., jurisdictions in which they practice, areas of expertise, size of law firm, and e-mail address. All new matters entered 80 by potential clients are then queried against this member law firm and member attorney information to identify those member law firms and attorneys who match the criteria of information entered 80 for each new matter request. Referring now also to FIG. 5, the system according to the present invention then preferably automatically generates an e-mail 280 to each member law firm or attorney which has been determined to match criteria entered 80 for each new matter request. This e-mail 280 informs each matching member law firm or attorney that a match has been detected. E-mail 280 preferably includes that data entered 80 in windows 130 , 140 and 150 ( 130 ′, 140 ′, and 140 ′, respectively), as well as the ID 220 and date the request was submitted. Referring now also to FIG. 6, upon receipt of the e-mail 280 , each receiving member law firm or attorney may choose to access more information regarding the referenced new matter request by either activating the HTML link 290 or simply accessing a predetermined Uniform Resource Locator (“URL”) address. Upon such, a web page 300 is preferably displayed, which enables a member law firm or attorney to access more information regarding any matter which has not been deleted or has expired based upon predetermined criteria. Referring now also to FIG. 1C, in the specific case of web page 300 , window 310 enables a member law firm or attorney to enter 330 a particular ID 220 which the member wishes to access information about, and a button 320 for directing the system according to the preferred form of the invention to retrieve that information. In a preferred embodiment of the invention, an ID and password corresponding to the member law firm or attorney attempting to access the new matter request information must be entered before such information will be displayed. Upon activation of the button 320 , the system preferably generates 340 a web page 350 (see FIG. 7) which includes the information entered by the potential client regarding the new matter request corresponding to the ID 220 entered into the window 310 . The member may then decide to either not respond at all to the request, download the information as a text file using HTML link 370 , e-mail the information to someone else using HTML link 380 or reply directly to the associated potential client who entered the new matter request displayed on the page 350 using the HTML link 390 . In this way, a maximum number of service providers can be put into contact with a potential client in a minimum amount of time, which enables the potential client to make a highly informed decision with a minimal amount of effort. In a preferred form of the invention, web pages are dynamically created and downloaded to the consumer's browser for display and interaction with. Such can be accomplished using Microsoft Active Server Pages (ASP) for example. Additionally, multiple database which are responsive to and utilized to dynamically generate the web pages are effected using Microsoft SQL server for example. The database tables that are preferably used include: a cases table, a casemail table, a case response table, a zip code table, a master firm list table and a registered attorneys table. The cases table records cases which have been entered into the system and preferably includes at least: a unique case number; a case remove number; whether the consumer is an individual or a business; if an individual, the individual's first and last names; if a business, the business name; an e-mail address for responses to the consumer; a zip code for the consumer; a phone number for the consumer, if entered; which state the attorney should practice in; the area of practice for the desired attorney; time considerations; when a response is needed by, if entered; time consideration comments; and some general information about the case. The casemail table preferably includes: information regarding a unique case number to which each record corresponds; the identity of a firm to which an e-mail has been sent for the case identified by the unique case identifier; the date that e-mail was sent; and, whether the case is still pending, i.e. not deleted. The case response table similarly preferably includes: information regarding a unique case number to which each record corresponds; the identity of a firm which has responded to an e-mail which was sent regarding the case identified by the unique case number; the date that response was sent; and, whether the case is still pending, i.e. not deleted. The zip code table preferably includes a list of all zip codes within the United States, and a corresponding longitude and latitude for each of those zip codes. The master firm list table preferably includes the identities and contact information of firms that may be interested in using a system according to the present invention. The registered attorneys table preferably includes those firms and attorneys from the master firm list which have registered to use the system according to the present invention, and their corresponding user names and passwords. Referring now also to FIGS. 8A and 8B, therein is illustrated a flow diagram 900 of a preferred form of the invention for entering a new case. The method begins with the system receiving a request to access the system, such as a standard HTTP request to access www.casematch.com using a browser via a conventional Internet connection (step 902 ). Upon receipt thereof, a start page such as that illustrated in FIG. 2, is served (step 904 ) to the browser requesting it, which then displays it. A user then, upon reading the page 30 , activates link 40 to enter a new case which is received by a system implementing the present invention (step 906 ). Upon receipt of request, a new case form 70 is served (step 908 ) to the browser requesting it, which then displays it in turn (see FIG. 3 ). A user, upon viewing the new case form 70 , completes the same by using in data tools 100 - 190 (standard radio buttons, text windows and drop-lists as are well known and commonly utilized). When completed, the user preferably activates the “SUBMIT” button 200 which is received by the system according to the present invention (step 910 ). Upon receipt of this request (step 910 ) and the data entered using tools 100 - 190 as is conventionally understood, the system reviews the data entered using tools 100 - 190 to see if they are valid (step 912 ). If they are not, for example if no data has been entered in one or more mandatory fields, an error process is invoked (step 914 ) which displays a message such as “The CaseMatch form was not completed accurately.” Fields that need to be completed are preferably displayed in red, and a message such as “Please go back and correct the following errors” is displayed to the user via the browser (step 914 ). The system then lists those fields that have invalid entries, i.e. are missing or are of an improper format for example. The system then preferably displays the page 70 again to the user, except that the page 70 includes those responses previously entered using tools 100 - 190 by the user. Of course, a button can be provided which clears all data entered using tools 100 - 190 whenever activated, so a user may begin afresh. Upon receipt of valid form entries (step 912 ), the system queries a master firms table for those attorneys and/or firms which meet the users received requirements as entered using tools 100 - 190 , and generates a results table (step 916 ). A format selection page is then preferably served to the browser (step 918 ) so the user may select whether to use automatic formatting of the results or a custom format (step 920 ). If an automatic formatting is selected at step 920 , than preferably the results generated at step 916 are queried and sorted by distance from the consumer's, or user's, zip code as entered (step 922 ). The system then generates a results table and serves it (step 928 ) to the user's browser for display consistently with the order determined. As the address of each firm/attorney returned by the query is known and the consumer's zip code is known, the distance can be easily calculated using conventional methods. If, the consumer, or user, selects to manually format the results, it is determined whether the entered formatting, e.g. what order to display the results in is valid (step 924 ). If not, an error process is performed (step 926 ) similar to the error process performed regarding step 914 , and the format selection form is served to the consumer's browser for correction or completion analogously to step 918 . If the selected formatting is determined to be valid, than the results are sorted according to the selected format (step 922 ) and a results table generated (step 928 ). A results page is then served (step 930 ) to the browser which includes the information in and is based upon the results table generated at step 928 . Upon receipt of this page and display thereof on a user's browser, the user can select either to display those firms/attorneys which match the criteria, i.e. are identified in the results table, in an automatic format or a custom format, using a radio button for example. Upon activation of a “NEXT” button (step 932 ) the system 920 the system determines whether the user selected automatic or manual formatting (step 934 ). More particularly, if manual formatting was selected, through use of radio button for example, the system determines if the number of results to display on each page is valid by checking that value entered in window (step 936 ). If valid, processing continues, if not valid, then the system performs error processing (step 937 ) analogous to that described. If manual formatting was selected, through the use of a radio button for example, then the results table which was generated in step 928 is resorted by that field selected (step 938 ), and processing continues. The system then regenerates the results table with the resorted data (step 922 ). The system then serves to the user's browser an attorneys view form (step 942 ). A user can now select those attorneys whom he wishes to have the system contact regarding his newly entered case by checking appropriate boxes as is well understood and conventionally used. Preferably, the system calculates the total number of selected firms from the total number of checked boxes and displays that number for confirmation by the user, consumer. Upon activation of “NEXT” button (step 944 ) the system verifies that the user selection made, those firms or attorneys selected, are valid, i.e. at least one firm/attorney is selected (step 946 ). If the selections are not valid, error processing (step 948 ) occurs as has been described, and the system redisplays the attorneys view page discussed with regard to step 942 . Upon determining the selections are valid at step 946 , the system serves a browser display select screen (step 950 ) to the user to allow a user to enter when the case he has just entered should become available for browsing by all registered attorneys/firms and not just those he opted to e-mail using the attorneys select page. Upon activation of a “NEXT” button (step 952 ), the system again determines whether the entries made using tools are valid (step 954 ), and if not performs error processing (step 956 ) as has been described and causes the browser select page to be redisplayed with the values that have previously been entered by the user. Upon validation of the browser information entered, the system generates a case identifier and case removal identifier (step 958 ). The generated identifiers are then included on a served identifiers page to the consumer's browser (step 960 ). Essentially, the case identifier is a unique identification associated with the record of the case, while the case removal identifier serves as a password for deleting the case record. The system then preferably updates a case table including each of the case records to include a new record for the case that has just been entered by the user (step 962 ). The system then preferably automatically generates an e-mail to each attorney selected by the consumer (step 964 ). In the preferred embodiment of the invention, only select information is forwarded to the attorneys selected, as all selected attorneys may not be registered members, and access should be limited to registered members as will be described. The system then preferably updates a casemail table to reflect each e-mail sent (step 966 ). Finally, the system preferably automatically generates an e-mail to the consumer confirming that e-mails have been sent to the requested attorneys (step 968 ). In an alternative form of the invention, the system waits a sufficient amount of time to verify no deliver errors have occurred prior to e-mailing the confirmation to the consumer at step 968 . If an error does occur, further processing can be performed, such as informing customer service directly and automatically. In the preferred form of the invention, there are two ways cases can be reviewed by attorneys/firms. The first is by responding to the automatically generated e-mail, while the second involves browsing cases which are still pending, i.e. have not been deleted. Referring first to the e-mail response method, as set forth, upon the selection of attorneys/firms by a consumer e-mails are automatically generated and sent. Upon receipt and reading of one of these automatically generated e-mails, the receiving attorney becomes aware of a potential client. However, in order to view details regarding this potential client the receiving attorney is preferably instructed to access a website to retrieve/display additional information as well as respond if desired. In the preferred form, each e-mail to each attorney/law firm includes a URL link which, when activated, enables the receiving attorney to directly access more information on the identified case. To accomplish this, the embedded URL link preferably includes a destination URL as well as the unique case identifier. Accordingly, when activated the URL link enables the receiving attorney to not only be forwarded to access the appropriate website, but to automatically access a dynamically generated webpage which includes further information about the case to which the receiving attorney is inquiring about. Alternatively, the inquiring attorney could access the system according to the invention using conventional techniques upon receiving the e-mail, and enter the unique case identifier using a web page. Either way, a case information is preferably generated using the information entered into the case table using conventional techniques. In order to access a case information page in the preferred form of the invention, the individual inquiring must be registered with the system according to the present invention. This is easily accomplished by assigning each registered attorney a unique user ID and password which must be entered before access will be allowed. In one form of the invention, the user ID and password can also be included in the URL link embedded in the e-mail, so it to can be passed to the system automatically and hence not independently verified by the user, if desired. Each generated case page preferably further includes a “Send Email” button. This button, when activated, preferably forwards the inquiring attorney to an e-mail page. Again, the e-mail page is preferably dynamically generated from the case table using conventional techniques. It should be noted however, that the consumer will often wish that their identity remain anonymous in contrast to conventional types of online services. Accordingly, the inquiring attorney can enter a message to be forwarded to the consumer into text window. Upon completion, the inquiring attorney activates a submit button and the system automatically generates an e-mail to the consumer without any further interaction by the inquiring attorney. In this way, the inquiring attorney can reply to the consumer's request without jeopardizing the anonymity of the consumer by disclosing a destination e-mail address. Alternatively, registered attorneys/firms can browse pending cases, i.e. cases which have been entered and not deleted, to determine if they have an interest in the same. To accomplish the same, an inquiring attorney can access a browser page using conventional techniques, e.g., by entering www.casematch.com, and then following appropriate menu prompts. Using data tools like those discussed above, an inquiring attorney can query the cases table for cases which meet certain criteria (i.e. are in New Jersey, any practice area) and sort the matching cases in a desired order (i.e. first by practice area, then by whether the consumer is an individual or business, then by the requested response date and finally by budget for example). By selecting the number of results by page and activating a “Submit” button, the system preferably queries the cases database and generates and serves a page which displays the results. This served page preferably includes navigation tools to enable the inquiring attorney to view other results as is well known and summary information for each case which matches the criteria entered by the searching attorney. It further preferably includes a review button for each case returned and an e-mail button. The review button, upon activation forwards the inquiring attorney to a case information page regarding the case selected and the E-mail button has the same function as the “Send E-mail” button discussed. A consumer can further decide to remove his case from the system, for example when he is no longer interested in pursuing it or has identified an attorney or firm to handle the case. To accomplish the same, the consumer preferably accesses a browser page as using conventional techniques (i.e. entering www.casematch.com and then activating a menu prompt or HTTP link to access the page). The consumer then enters the unique case identifier he was provided with into window and the case removal identifier he was provided with into text windows as prompted. Upon activating a “Continue” button, the system verfies that the unique case identifier and case remove number entered using page are valid and correspond to a single case, and if so generates and serves a confirmation page. If the data entered is not valid, error processing as discussed is again performed and case removal page is caused to be redisplayed to the user. Once the consumer verifies that the information contained is accurate, and that it indeed reflects the case he wishes to remove he activates the “Confirm Removal” button which causes the system to update the cases table to reflect the case has been removed (e.g., sets a deleted flag to true for example in the cases table). Although the invention has been described and pictured in a preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example, and that numerous changes in the details of construction and combination and arrangement of parts may be made without departing from the spirit and scope of the invention as hereinafter claimed. It is intended that the patent shall cover by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.

A computerized method for matching potential clients with professional services providers which meet their personalized criteria and are interested in providing particular services to them including the steps of: presenting a first electronic document including a plurality of data entry devices to the potential clients via a computer network; receiving data entered using the data entry devices, the received data being indicative of the criteria; automatically comparing the received data to data stored in a storage medium to identify one or more suitable professional services providers; automatically generating and transmitting via the computerized network an electronic mail message to the identified one or more service providers, the electronic message including information indicative of a portion of the received data; and, receiving a response from at least one responding one of the one or more identified service providers, and automatically providing information indicative of another portion of the received data to the responding one of the service providers.

RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 60/334,781 filed on Nov. 15, 2001. BACKGROUND OF THE INVENTION Well-defined transition metal carbene complexes have emerged as the catalysts of choice for a wide variety of selective olefin metathesis transformations [F. Z. Döbrwald, Metal Carbenes in Organic Synthesis ; Wiley VCH, Weinheim, 1999]. These transformations include olefin cross metathesis (CM), ring-opening metathesis (ROM), ring-opening metathesis polymerization (ROMP), ring-closing metathesis (RCM), and acyclic diene metathesis (ADMET) polymerization [K. J. Ivin and J. C. Mol, Olefin Metathesis and Metathesis Polymerization ; Academic Press, London, 1997]. Of particular importance has been the development of ruthenium carbene catalysts demonstrating high activity combined with unprecedented functional group tolerance [T. M. Trnka and R. H. Grubbs, Acc. Chem. Res ., 2001, 34, 18-29]. Olefin metathesis serves as a key reaction for the development of a range of regioselective and stereoselective processes. These processes are important steps in the chemical synthesis of complex organic compounds and polymers and are becoming increasingly important in industrial applications. [see for example Pederson and Grubbs U.S. Pat. No. 6,215,019]. An initial concern about using ruthenium olefin metathesis catalysts in commercial applications has been reactivity and catalyst lifetime. The original breakthrough ruthenium catalysts were primarily bisphosphine complexes of the general formula (PR 3 ) 2 (X) 2 Ru═CHR′ wherein X represents a halogen (e.g., Cl, Br, or I), R represents an alkyl, cycloalkyl, or aryl group (e.g., butyl, cyclohexyl, or phenyl), and R′ represents an alkyl, alkenyl, or aryl group (e.g., methyl, CH═CMe 2 , phenyl, etc.). Examples of these types of catalysts are described in U.S. Pat. Nos. 5,312,940, 5,969,170 and 6,111,121. Though they enabled a considerable number of novel transformations to be accomplished, these bisphosphine catalysts can exhibit lower activity than desired and, under certain conditions, can have limited lifetimes. More recent developments of metathesis catalysts bearing a bulky imnidizolylidine ligand [Scholl et. al. Organic Letters 1999, 1, 953-956] such as 1,3-dimesitylimidazole-2-ylidenes (IMES) and 1,3-dimesityl4,5-dihydroimidazol-2-ylidenes (sIMES), in place of one of the phosphine ligands have led to greatly increased activity and stability. For example, unlike prior bisphosphine complexes, the various imidizolyidine catalysts effect the efficient formation of trisubstituted and tetrasubstituted olefins through catalytic metathesis. Examples of these types of catalysts are described in PCT publications WO 99/51344 and WO 00/71554. Further examples of the synthesis and reactivity of some of these active ruthenium complexes are reported by A. Fürstner, L. Ackermann, B. Gabor, R. Goddard, C. W. Lehmann, R. Mynott, F. Stelzer, and O. R. Theil, Chem. Eur. J ., 2001, 7, No. 15, 3236-3253; S. B. Gaber, J. S. Kingsbury, B. L. Gray, and A. H. Hoveyda, J. Am. Chem. Soc ., 2000, 122, 8168-8179; Blackwell H. E., O'Leary D. J., Chatterjee A. K., Washenfelder R. A., Bussmann D. A., Grubbs R. H. J. Am. Chem. Soc. 2000, 122, 58-71; Chatterjee, A. K., Morgan J. P., Scholl M., Grubbs R. H. J. Am. Chem. Soc . 2000, 122, 3783-3784; Kingsbury, J. S.; Harrity, J. P. A.; Bonitatebus, P. J.; Hoveyda, A. H. J. Am. Chem. Soc . 1999, 121, 791-799; Harrity, J. P. A.; Visser, M. S.; Gleason, J. D.; Hoveyda, A. H. J. Am Chem. Soc . 1997, 119, 1488-1489; and Harrity, J. P. A.; La, D. S.; Cefalo, D. R.; Visser, M. S.; Hoveyda, A. H. J. Am. Chem. Soc . 1998, 120, 2343-2351. The improvements in catalyst activity and expansion of potential substrates resulted in the ruthenium metathesis systems becoming attractive candidates for use in industrial scale processes. In particular, many of the targeted products of olefin metathesis are useful as intermediates in flavors and fragrances, pharmaceuticals and other fine chemicals. Thus, a second major concern has involved ruthenium residues that may be present in the products produced by metathesis. To address this issue, several catalyst removal techniques have been developed [Maynard and Grubbs in Tetrahedron Letters 1999, 40, 4137-4140; L. A. Paquette, J. D. Schloss, I. Efremov, F. Fabris, F. Gallou, J. Mendez-Andino and J. Yang in Org. Letters 2000, 2,1259-1261; and Y. M. Ahn; K. Yang, and G. I. Georg in Org. Letters 2001, 3, 1411], including that described by Pederson and Grubbs [Pederson and Grubbs, U.S. Pat. No. 6,215,049] which is still the most amenable to large scale reactions. Ruthenium metathesis catalysts with a wide range of reactivity and that could be easily removed from the product were now available. Further progress towards catalyst selectivity, stability, and removal has been recently published by Hoveyda and others [Kingsbury, J. S.; Harrity, J. P. A.; Bonitatebus, P. J.; Hoveyda, A. H. J. Am. Chem. Soc . 1999, 121, 791-799] with the demonstration of new, readily recyclable catalyst systems containing chelating carbene species (FIG. 1) that are exceptionally stable and can even be purified by column chromatography in air. For example, the tricyclohexylphosphine-ligated variant, Catalyst 601 (FIG. 1), can be recovered in high yield from the reaction mixture by simple filtration through silica. Hoveyda and coworkers also demonstrated [Cossy, J.; BouzBouz, S.; Hoveyda, A. H. J. Organometallic Chemistry 2001, 624, 327-332] that by replacement of the phosphine with the sIMES ligand, Catalyst 627 (FIG. 1) actively promotes the cross-metathesis of acrylonitrile and terminal olefins in moderate to excellent yields (20% to 91%) with a cis to trans olefin ratios that range from 2:1 to over 9:1. Related chelating carbene catalysts are described in U.S. Patent Application Publication No. 2002/010713 8 and U.S. Pat. No. 6,306,987. Prior methods used to make these chelating carbene complexes include treating (Ph 3 P) 3 RuCl 2 with the appropriate diazo species at low temperatures or treatment of a metathesis-active metal carbene complex with the parent styrene in the presence of CuCl followed by column chromatography FIG. 2). While both of these methods yield the desired compound, they are difficult to scale up. Maintaining very low temperatures on larger reaction vessels requires expensive equipment, and diazo species are prone to violent decomposition under certain conditions. Using the o-isopropoxy styrene/CuCl route is also not amenable to large scale due to the requirement to purify the product by column chromatography. A further shortcoming includes the use of the Wittig reaction to yield the key styrene intermediate. Wittig reactions are not convenient on a commercial scale because of the high costs of the reagents and the byproduct, triphenylphosphine oxide, produces an excessive mass of waste. Alternatives to Wittig reactions would include Heck, Stille or Suzuki coupling of vinyl trialkyltin, vinyl triflates or vinyl borate; respectively, to a halo-phenol substrate. These starting materials are generally expensive, and the reactions with trialkyl tin reagents involve toxic compounds which require special waste disposal procedures. Finally the styrene itself is prone to polymerization under some of the conditions required to make the “Hoveyda-type” catalysts. Therefore, there is a need for an efficient and economical synthesis to chelating carbene type ruthenium metathesis catalysts in larger quantities. The present invention describes efficient and versatile routes to useful and valuable Hoveyda-type catalysts with chelating phenyl carbene ligands while eliminating expensive and toxic reagents. The present invention describes the synthesis of substituted olefins that are precursors to catalyst complexes and their use as reagents to prepare olefin metathesis catalysts with chelating carbene ligands. SUMMARY OF THE INVENTION The present invention comprises methods for the use of novel chelating ligand precursors for the preparation of olefin metathesis catalysts. The resulting catalysts comprise monomeric species which are air stable, are capable of promoting various forms of metathesis reactions in a highly efficient manner, and can be recovered from the reaction mixture and reused. One embodiment of the present invention is the use of internal olefin compounds, specifically beta-substituted styrenes, as ligand precursors instead of terminal olefin compounds such as unsubstituted styrenes (FIG. 3). Although internal olefins tend to be less reactive than terminal olefins, we have surprisingly found that the beta-substituted styrenes are sufficiently reactive to efficiently produce the desired catalyst complexes. Compared with the styrene compounds, the beta-substituted styrenes are much easier and less costly to prepare in large quantities and are more stable in storage and use since they are less prone than terminal styrenes to spontaneous polymerization. Another embodiment of the present invention are methods of preparing chelating-carbene metathesis catalysts without the use of CuCl as previously required. In previous reports, CuCl was used to sequester phosphine ligands which shifts the equilibrium of metathesis reactions to product formation. The use of CuCl in large scale synthesis is problematic in that the resulting metathesis catalyst must be purified by chromatography before recrystallization, requiring large volumes of silica and solvent [Kingsbury et. al. J. Am. Chem. Soc . 1999, 121, 791-799]. The present invention eliminates the need for CuCl by replacing it with organic acids, mineral acids, mild oxidants or even water, resulting in high yields of Hoveyda-type metathesis catalysts. The phosphine byproduct can be removed by an aqueous wash or filtration, thereby eliminating the chromatography step and allowing catalysts to be readily isolated by crystallization from common organic solvents. A further embodiment of the present invention is an efficient method for preparing chelating-carbene metathesis catalysts by reacting a suitable ruthenium complex in high concentrations of the novel ligand precursors followed by crystallization from an organic solvent. For example, in this manner Catalyst 601 can be simply isolated by filtering a hexane solution of the reaction mixture resulting from the reaction of neat ligand precursor and a ruthenium carbene complex. By using the beta-substituted styrene derivatives, the excess, unreacted ligand is recoverable from such reaction mixtures and can be reused. This is difficult with the parent styrenes due to the propensity of those materials to polymerize under reaction and workup conditions. DETAILED DESCRIPTION OF THE INVENTION The present invention describes the synthesis of “Hoveyda-type” chelating carbene metathesis catalysts from the cross metathesis of novel ligand precursors and metal carbene complexes. Although any metathesis-active metal carbene complex is suitable for use in the present invention, preferred metal complexes include the Grubbs-type compounds described in U.S. Pat. Nos. 5,312,940, 5,969,170, 6,077,805, 6,111,121 and 6,426,419 and PCT publications WO 99/51344 and WO 00/71554. These complexes have the general formula X 1 X 2 L 1 (L 2 ) m M═CR 1 R 1 , wherein X 1 and X 2 are each, independently, any anionic ligand; L 1 and L 2 are each, independently, any neutral electron donor ligand; m is 1 or 2; M is ruthenium or osmium; and R 1 and R 2 are each, independently, hydrogen or a group selected from the group consisting of alkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylthio, alkylsulfonyl, alkylsulfinyl and trialkylsilyl, any of which may be optionally substituted with a functional group selected from the group consisting of halogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, alkoxy, alkenyloxy, aryloxy, alkoxycarbonyl, carbonyl, alkylamino, alkylthio, alkylsulfonyl, nitrile, nitro, alkylsulfinyl, trihaloalkyl, perfluoroalkyl, carboxylic acid, ketone, aldehyde, nitrate, cyano, isocyanate, hydroxyl, ester, ether, amine, imine, amide, sulfide, disulfide, sulfonate, carbamate, silane, siloxane, phosphine, phosphate, or borate. In these preferred metal carbene complexes, R 1 and R 2 may be linked to form a cyclic group, and any two or three of X 1 , X 1 , and L 1 may be linked to form a multidentate ligand and two L 2 ligands, if m=2, may be linked to form a bidentate ligand. One type of chelating carbene complex, for example catalyst 601 or catalyst 627, may also be reacted with the ligand precursors of the present invention to make different chelating carbene complexes. The ligand precursors of the present invention are functionalized beta-substituted styrene compounds, which may be conveniently prepared by the isomerization of functionalized allylbenzenes, with the structure shown in FIG. 4. Wherein: Y is a heteroatom such as oxygen (O), sulfur (S), nitrogen (N), or phosphorus (P); Z is a group selected from hydrogen, alkyl, aryl, functionalized alkyl, functionalized aryl where the functional group(s) may independently be one or more or the following: alkoxy, aryloxy, halogen, carboxylic acid, ketone, aldehyde, nitrate, cyano, isocyanate, hydroxyl, ester, ether, amine, imine, amide, sulfide, disulfide, carbamate, silane, siloxane, phosphine, phosphate, or borate. n is 1, in the case of a divalent heteroatom such as O or S, or 2, in the case of a trivalent heteroatom such as N or P; R 3 and R 4 are independently selected from the group consisting of hydrogen, C 1 -C 20 alkyl, C 6 -C 20 aryl, C 1 -C 20 alkoxy or C 6 -C 20 aryloxy; R 5 , R 6 , R 7 , and R 8 are each, independently, selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, alkoxy, alkenyloxy, aryloxy, alkoxycarbonyl, carbonyl, alkylamino, alkylthio, alkylsulfonyl, nitrile, nitro, alkylsulfinyl, trihaloalkyl, perfluoroalkyl, carboxylic acid, ketone, aldehyde, nitrate, cyano, isocyanate, hydroxyl, ester, ether, amine, imine, amide, sulfide, disulfide, sulfonate, carbamate, silane, siloxane, phosphine, phosphate, or borate. Additionally, any two or more of R 5 , R 6 , R 7 , and/or R 8 may be independently connected through hydrocarbon or functionalized hydrocarbon groups forming aliphatic or aromatic rings. Furthermore, one who is skilled in the art will recognize that R 8 should be chosen such that its steric bulk or chemical functionality does not interfere with the cross-metathesis reaction between the ligand precursor and the metal carbene complex. Any one or more of R5, R 6 , R 7 and R 8 (but preferably any of R 5 , R 6 and R 7 ) may be a linker to a solid support such as silica, swellable polymeric resins, dendritic polymers, and the like as, for example, described in U.S. Patent Application Publication No. 2002/0107138 or by Grela (et al.) in Tetrahedron Letters , 2002, 43, 9055-9059 for terminal-styrene ligand precursors. Preferred ligand precursors are beta-methyl styrenes wherein Y is oxygen or sulfur; n is 1; Z is alkyl, aryl or trialkylsilyl; and R 3 and R 4 are both hydrogen. Particularly preferred ligand precursors are alkoxy-substituted beta-methyl styrenes wherein Y is oxygen; n is 1; Z is methyl, isopropyl, sec-butyl, t-butyl, neopentyl, benzyl, phenyl or trimethylsilyl; and R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are all hydrogen. Examples of particularly preferred ligand precursors of these types include 2-methoxy-β-methylstyrene, 2-isopropoxy-β-methylstyrene and 2-isopropoxy-3-phenyl-β-methylstyrene: The precursor compounds for chelating ligands are easily prepared in high yields from commercially available starting materials. Treatment of allyl aryl compounds with an isomerization catalyst cleanly migrates the double bond one carbon closer to the aryl ring forming a beta-substituted styrenic olefin (FIG. 4). We have found that (PPh 3 ) 3 RuCl 2 is a preferred, highly active isomerization catalyst that is effective at amounts ranging from about 0.001 to 20 mole percent relative to the allyl aryl compound. It is preferable to isomerize the allylphenol compounds prior to further fanctionalization, since the hydroxy protons serve to activate the catalyst and the reactions can therefore be run neat. For other compounds without their own protic source, it is necessary to add an alcohol or other proton source to initiate the isomerization catalysis. From the structures shown in FIG. 4, one skilled in the art can appreciate the diversity of substitution on the aromatic system that can be achieved. This allows the ligand to be fine-tuned for specific applications. For the case where Y is oxygen, a wide variety of allyl phenol starting materials are easily produced by the Claisen rearrangement (FIG. 5) of allylic aryl ethers [ March's Advanced Organic Chemistry ; 5 th Edition, Eds. M. B. Smith and J. March; John Wiley and Sons, New York, N.Y. 2001, pp. 1449-1452]. Similar rearrangements are operative for the case where Y is nitrogen, although more forcing conditions are typically required. The above described ligand precursors can be used to prepare metathesis catalysts with a chelating carbene group. The preferred chelating carbene complexes have the structure shown in FIG. 6. The most preferred chelating carbene complexes that are made by this method are Hoveyda-type complexes including, but not limited to, catalyst 601 and catalyst 627. In the most basic practice of the present invention, as with the parent styrenes, it is possible to mix a metathesis active metal carbene complex with the ligand precursor in a suitable solvent to effect the transformation. Preferred solvents typically include, but are not limited to, chlorinated solvents (such as methylene chloride, dichloroethane, chlorobenzene, and dichlorobenzenes), ethereal solvents (such as tetrahydrofuran or dioxane), aromatic solvents (such as benzene, toluene, or xylenes), and hydrocarbon solvents (such as hexanes, heptane, and petroleum distillate fractions). In general, at least one equivalent, and preferably an excess amount, of the ligand precursor is utilized. Depending upon the reactivity of the metathesis-active metal carbene complex, the reaction may proceed at room temperature, or even lower, or may need to be heated. As the progress of these reactions can be conveniently monitored by a variety of techniques including thin-layer chromatography (TLC), those skilled in the art can readily ascertain the appropriate conditions of time and temperature to achieve high conversions to the desired chelating carbene complexes. In general, these reactions proceed more slowly and/or require somewhat higher reaction temperatures than comparable reactions with terminal styrenes. In order to increase the reaction rates and achieve higher conversion, high ratios of ligand precursor to metal carbene complex can be utilized In fact, in the practice of the present invention, the reaction can be performed using neat ligand precursor as the solvent. In general, three to ten mole-equivalents of ligand precursor will give reasonable reaction rates and high conversions, although higher amounts may be used. This approach cannot be utilized with the terminal styrene ligand precursors due to their propensity to spontaneously polymerize under the reaction conditions. Upon completion of the reaction, the ligand precursor can be distilled off of the reaction mixture and the chelating carbene product recrystallized from an appropriate solvent Alternatively, the chelating carbene product can be precipitated by the addition of an appropriate nonsolvent and the unreacted ligand precursor recovered by distillation of the mother liquor. The beta-substituted styrene compounds are sufficiently robust so that high recoveries can be achieved by these methodologies, which would not be practical with the easily polymerized terminal styrenes. In general, treatment of one mass equivalent of a ruthenium carbene complex with between 1 and 20 mass equivalents of ligand precursor in the presence of an optional co-solvent (generally between about 1-20 mass equivalents relative to the ruthenium complex) yields a thick mixture that gradually looses viscosity during the course of the reaction. Optionally the mixture can be heated or cooled. The mixture may also be exposed to a static or dynamic vacuum. The reaction is preferably conducted under an inert atmosphere but may be conducted in air unless the metal carbene complex is particularly air-sensitive. After 3 hours to 7 days of stirring, the reaction is usually complete and the product may be isolated as described above. A complementary method for increasing reaction rates and conversion utilizes an additive to sequester the ligand that is displaced from the metal carbene complex during the course of the reaction. When the displaced ligand is a phosphine ligand, as is typical, the sequestering agent that has been commonly used in cuprous cloride (CuCl), although this is difficult to separate from the product without using chromatograhy which is impractical at large scale. Surprisingly, we have found that replacement of the CuCl with mineral acids, organic acids or mild oxidants in the presence of the ligand precursors of the present invention is also very effective. Treatment of ruthenium carbene complexes with between 1 to 10 equivalents of ligand precursor and between 0.1 to 10 equivalents acid or mild oxidant yields the new catalyst containing the chelating carbene moity. After the reaction is complete, the displaced ligand and the sequestering agent can be readily removed from the mixture by extraction into water. The product can then be simply crystallized from the resulting solution in organic solvents in very high yield, eliminating the need for column chromatography. Preferred sequestering agents include hydrochloric acid, solutions of hydrogen chloride in ethereal solvents (such as diethyl ether, tetrahydrofuran, or dioxane), gaseous hydrogen chloride dissolved in the reaction mixture, glacial acetic acid, bleach, and dissolved oxygen. Water can be utilized as a sequestering agent for particularly basic ligands such as tricyclohexylphosphine (TCBP or PCy 3 ). The use of sequestering agents is particularly perferred when using very robust metal carbene complexes such as those containing IMES or sIMES ligands. When using less robust complexes such as ruthenium carbenes ligated with two phosphine ligands, greater care is needed and it is desirable to utilize the mildest sequestering agents or to slowly add the sequestering agents over the course of the reaction. EXAMPLES Example 1 Synthesis of o-hydroxy beta-methyl styrene [1] from 2-allylphenol. To a dry 100 mL round-bottom flask containing a magnetic stirbar was added 25 g (186 mmol) of 2-allylphenol (Aldrich). The flask was sparged with argon for 30 minutes, followed by the addition of 71 mg (0.05 mol %) of (PPh 3 ) 2 Cl 2 Ru, a highly effective double-bond isomerization catalyst, and then heated to 70° C. for 17.5 hours. GC analysis* indicated>99% conversion of 2-allyl phenol to o-hydroxy beta-methyl styrene. GC results show ortho-hydroxy beta-methyl styrene R t 8.51 minutes and R t 11.13 minutes (Z and E isomers), and 2-allylphenol R t 8.86 minutes. The catalyst was removed with tris-hydroxymethyl phosphine (THP), as previously described by Pederson and Grubbs [U.S. Pat. No. 6,219,019], to yield 25 g, quantitative yield. Isomeric ratio of E:Z isomers was 45:55. *GC Analysis: HP 5890 GC with DB 225 capillary GC column (30 m×0.25 mm ID×0.25 μm film thickness) Head pressure 15 psi, FID detection. Method: 100° C. for 1 minute then 10° C./minute to 210° C. for 6 minutes. Example 2 Synthesis of ortho-Isopropoxy beta-Methyl Styrene [2]. Protection of an aromatic hydroxyl group with isopropyl was as described by T. Sala and M. V. Sargent, J. Chem. Soc., Perkin Trans . 1, 2593, (1979). To a dry 500 mL round-bottom flask containng a magnetic stirbar was added 50 g (373 mmol) of ortho-hydroxy beta-methyl styrene, 57.3 g (466 mmol) isopropyl bromide, 300 mL of anhydrous dimethylformamide (DMF), and 64 g (466 mmol) K 2 CO 3 . The heterogeneous mixture was warmed to 60° C. After 9 hours the reaction was 57% converted, 30 g (244 mmol) isopropyl bromide and 32 g (232 mmol) of K 2 CO 3 was added, and stirring was continued. After 48 hours, GC analysis indicated >98% conversion to ortho-isopropoxy beta-methyl styrene. GC results: ortho-hydroxy beta-methyl styrene R t 8.51 minutes and R t 11.13 minutes (Z and E isomers), ortho-isopropoxy beta-methyl styrene R t 7.35 minutes (Z-isomer) and R t 8.30 minutes (E-isomer). The reaction was cooled to room temperature and 200 mL of water and 100 mL of tertiary-butyl methyl ether (TBME) were added and mixed. The phases were separated and the aqueous phase was washed with another 100 ml of TBME. The organic phases were combined and washed with 2×100 mL of water, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to yield crude ortho-isopropoxy beta-methyl styrene. Vacuum distillation (Bpt 1.0 60° C. to 65° C.) yielded 61.3 g (348 mmol) or 93% isolated yield. 1 H NMR (300 MHz) CDCl 3 δ: 7.8 (d, 1H aromatic), 7.5 (m, 1H, aromatic), 6.90 (bt, 2H, aromatic), 6.4 (dd, 1H, Ph-C H ═CH), 6.0 (m, 1H, Ph-CH ═C H CH 3 ), 4.64 (m, 1H, C H (CH 3 ) 2 ), 1.35 (J 6.3 Hz, 6H, CH(C H 3 ) 2 ). 13 CNMR(75MHz) CDCl 3 δ: 130.23, 127.68, 127.52, 126.36, 125.99, 125.71, 125.53, 120.59, 119.92, 114.08, 113.96, 70.58, 22.298, 19.09, 14.87. Example 3 Alternative Synthesis of ortho-Isopropoxy Beta-bethyl Styrene [2]: Synthesis of ortho-Isopropoxy Salicylaldehyde [3]. Similar to the procedure of Example 2, 6.5 g (53.2 mmol) of salicylaldehyde, 100 mL of anhydrous DMF, 6.5 g of K 2 CO 3 , and 10 g of isopropyl bromide (81.3 mmol) were added to a dry 250 mL round-bottom flask containing a magnetic stirbar. The heterogeneous mixture was stirred with heating to 60° C. for 24 hours when GC analysis indicated complete conversion to o-isopropoxy salicylaldehyde. Water 100 mL was added and the organics were washed with 2×100 mL of TBME, the TBME phases were combined and washed with 2×50 mL water, dried with anhydrous sodium sulfate, filtered and concentrated to yield [3] (8.3 g, 95% yield). Salicylaldehyde R t 6.473 minutes, ortho-isopropoxy salicylaldehyde R t 10.648 minutes. 1 H NMR (300 MHz) CDCl 3 δ: 10.46 (C H O), 7.8 (d, 1H aromatic), 7.5 (m, 1H, aromatic), 6.90 (t, 2H, aromatic), 4.64 (m, 1H, C H (CH 3 ) 2 ), 1.35 (J 3 6.3 Hz, 6H, CH(C H 3 ) 2 ). Example 4 Alternative Synthesis of ortho-Isopropoxy beta-Methyl Styrene [2]: Synthesis of ortho-Isopropoxy (2′-Hydroxypropyl) Benzene [4]. To a 50 mL round-bottom flask was added 1 g (7.0 mmol) of [3] and 25 mL of anhydrous tetrahydrofuran (THF). The flask was sparged with Argon while cooling to −15° C. over 15 minutes. Ethyl magnesium chloride (3 mL of 3 M in ether) was added drop wise over 10 minutes. The reaction was warned to room temperature and quenched with water-saturated ammonium chloride. GC analysis indicated >99% conversion to ortho-isopropoxy (2′-hydroxypropyl) benzene with R t =10.969 minutes (4.1%) and 11.374 minutes (95.9%), E and Z isomers. The product was isolated by usual methods to yield [4] (1.4 g, quantitative yield). This product was used in the next reaction without further purification. Example 5 Alternative Synthesis of ortho-Isopropoxy beta-Methyl Styrene [2]. To a 250 mL round-bottom flask was added 1.4 g (7.0 mmol) of [4], 100 mL of anhydrous toluene, and 100 mg of p-toluene sulfonic acid. The mixture was heated to 90°C. for 90 minutes when GC analysis indicated complete conversion to [2] with an isomeric ratio of E:Z isomers of 97:3. 1 H NMR and 13 C NMR were in agreement with previously synthesized material. Example 6 Synthesis of [(sIMES)(o-isopropoxyphenylmethylene) Ruthenium Dichloride] [6] from (sIMES)(PCy 3 )Cl 2 Ru═CHPh [5] and CuCl. To a dry 100 mL round-bottom flask containing a magnetic stirbar, under argon, was added 1.79 g (2.1 mmol, 1.0 equiv) [5], CuCl (521 mg, 5.28 mmol, 2.51 equiv), and 25 mL of anhydrous CH 2 Cl 2 . Ligand precursor [2] (403 mg, 2.1 mmol, 1.0 equiv) was added to the reddish solution in 20 mL of CH 2 Cl 2 at room temperature. A reflux condenser was added and the mixture was heated for 70 minutes, under argon. The crude product was concentrated and loaded onto silica gel and eluted with 2:1 pentane:CH 2 C 2 then 1:1 pentane:CH 2 Cl 2 to remove a dark green band. The column was washed with CH 2 Cl 2 , then Et 2 O. The green and yellow bands were combined and concentrated under reduced pressure to yield a dark green solid. The solvents are removed under reduced pressure and the solid was crystallized from hexane to yield 1.07 g (1.70 mmol, 85%) of [6]. 1 H NMR (300 MHz, CDCl 3 ) δ: 16.56 (s, 1H, Ru═CHAr), 7.48 (m, 1H, aromatic CH), 7.07 (s, 4H, mesityl aromatic CH), 6.93 (dd, J=7.4 Hz, 1.6 Hz, 1H, aromatic CH), 6.85 (dd, J=7.4 Hz, 1H, aromatic CH), 6.79 (d, J=8.6 Hz, 1 H, aromatic CH) 4.90 (septet, J=6.3 Hz, 1H,(CH 3 ) 2 C H OAr), 4.18 (s, 4H, N(CH 2 ) 2 N), 2.48 (s, 12 H, mesityl o-CH 3 ), 2.40 (s, 6H, mesityl p-CH 3 ), 1.27 (d, J═5.9 Hz, 6H, (CH 3 ) 2 CHOAr. 13 C NMR ( 75 MHz, CDCl 3 ) δ: 296.8 (q, J=61.5 Hz), 211.1, 152.0, 145.1, 145.09, 138.61, 129.4 (d, J NC 3.9 Hz), 129.3, 129.2, 122.6, 122.1, 122.8, 74.9 (d, J OC 10.7 Hz), 51.4, 30.9, 25.9, 21.01. Example 7 Synthesis of [6]from [5] and Bleach. To a dry 100 mL round-bottom flask containing a magnetic stirbar was added 1.79 g (2.1 mmol, 1.0 equiv) of [5], 10 mL of household bleach (i.e., aqueous sodium hypochlorite), and 25 mL of CH 2 Cl 2 . Ligand precursor [2] (403 mg, 2.1 mmol equiv) was added to the reddish solution in 20 mL of CH 2 Cl 2 at room temperature. A reflux condenser was added and the mixture was heated for 4 hours. The organic phase was washed with water, isolated, neutralized, dried, filtered and concentrated under reduced pressure to yield a green solii Crystallization from pentane yielded 43% of [6] of acceptable purity as indicated by NMR spectral analysis. Example 8 Synthesis of [6] from [5] and Ethereal HCl. To a dry 100 mL round-bottom flask containing a magnetic stirbar was added 1.79 g (2.1 mmol, 1.0 equiv) of [5], 25 mL of CH 2 Cl 2 , and 2.4 mL of ethereal HCl (2.0 M, 2.0 equiv). Ligand precursor [2] (420 mg, 2.4 mmol, 1.14 equiv) was added to the reddish solution in 20 mL of CH 2 Cl 2 at room temperature. A reflux condenser was added and the mixture was heated for 1 hour. The organic phase was washed with 2×25 mL water, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to yield a green solid. Crystallization from CH 2 Cl 2 /hexane yielded 161 (1.03 g, 78% yield) as indicated by NMR spectral analysis. Example 9 Synthesis of [(PCy 3 )(o-isopropoxyphenylmethylene) Ruthenium Dichloride] [8] from (PCy 3 ) 2 Cl 2 Ru=CHPh [7]. Ruthenium complex [7] (270 g, 0.32 moles) was charged into a 2roundbottom flask. Ligand precursor [2] (505 g, 2.8 moles) was then added, and one neck of the flask was fitted with a gas adapter, another with a stopper and the third with a distillation head and receiver flask. The flask was placed under vacuum and slowly heated to 80° C. The mixture was maintained at between 65° C. and 70° C. under vacuum for 24 hours. The temperature was raised to 80° C. and the remaining ligand precursor was distilled away. The vacuum was broken and hexanes (1 L) was added to the flask. The reaction mixture was stirred for several minutes then filtered. The solids were washed with warm hexanes (3×100 mL) yielding [8] (962 g, 49% yield) as indicated by NMR spectral analysis. Example 10 Synthesis of [8] from (PCy 3 ) 2 Cl 2 Ru=CH—CH═C(CH 3 ) 2 [ 9]. Ruthenium complex [9] (48 g, 0.059 moles) was charged to a 1 L roundbottom flask and ligand precursor [2] was charged along with toluene (400 g). A reflux condensor was attached to the flask and kept at 15° C. The mixture was warmed to 70° C. under vacuum for 12 hours. The condensor was warmed to 45° C. and the toluene was removed in vacuuo. The mixture was then heated to 80° C. for 48 hours under a static vacuum. A distillation head was attached to the flask and the remaining ligand precursor distilled away in vacuo. 500 mL of hexanes was added to the flask and the mixture was allowed to cool to room temperature with mixing. The mixture was filtered and the solids washed with hexanes (100 mL) yielding 16.7 g (46% yield) of [8] as indicated by NMR spectral analysis. Example 11 Synthesis of [8] from [9] with Hydrochloric Acid. A mixture of methylene chloride (200 g) and ligand precursor [2] (200 g, 1.136 moles) was charged into a roundbottom flask, warmed to 40° C., and degassed by sparging with nitrogen gas. Ruthenium complex [9] (100 g, 0.125 moles) was then added to the mixture against a nitrogen sparge. Hydrochloric acid (6N, 20 mL, 0.120 moles) was added slowly dropwise through an addition funnel over a period of three hours to the stirred mixture, which was maintained at 40° C. under nitrogen. After stirring for an additional hour at 40° C., analysis by thin-layer chromatography (TLC) indicated only partial conversion. The mixture was then stirred for an additional two hours at 50° C. and 1 hour at 60° C. until TLC suggested nearly complete conversion. An additional 5 mL of 6N hydrochloric acid was then added and the mixture stirred for two hours to assure completion. While still warm, 100 mL of methanol was added, and the resulting mixture poured into 1,400 mL of methanol to precipitate the product. The mixture was filtered and the solids washed and dried to yield 47.5 g (63% yield) of [8] as indicated by TLC analysis. Example 12 Synthesis of [8] from [9] with Water. A mixture of toluene (200 mL), ligand precursor [2] (100 g, 0.568 moles), ruthenium complex [9] (49 g, 0.061 moles) and water (100 ml) was charged into a roundbottom flask, sparged with nitrogen, and vigorously stirred overnight at 80° C. Analysis by TLC indicated nearly complete conversion. Hydrochloric acid (6N, 10 mL) was then added and the mixture stirred for several minutes to assure completion. The aqueous layer was removed and 400 mL of methanol added to precipitate the product. After stirring overnight, the mixture was filtered and the solids washed with methanol (50 mL), acetone (50 mL) and hexanes (50 mL) and dried to yield 19 g (52% yield) of [8]. Example 13 Synthesis of (61 from [5] and Hydrochloric Acid in THF. Ligand precursor [2] (5.28 g, 0.030 mole) and 50 mL of a mixture of 1 part concentrated hydrochloric acid in 5 parts tetrahydrofuran were added to a dry 500 mL round-bottom flask containing a magnetic stirbar. The mixture was degassed for ten minutes with a nitrogen sparge before 10 g (0.012 mole) of [5] was added. The reaction mixture was then heated to 60° C. for two hours when TLC analysis indicated that conversion was complete. After cooling to room temperature, the product precipitated, was collected by filtration, and washed with methanol to yield 4.33 g of [6] (59% yield). The filtrates were combined and refiltered to yield a second crop of 1.07 g of [6], giving an overall yield of 73%. Example 14 Synthesis of [6] from [5] and Hydrochloric Acid in THF. Ligand precursor [2] (2.64 g, 0.015 mole) and 30 mL of a mixture of 1 part concentrated hydrochloric acid in 5 parts tetrahydrofuran were added to a dry round-bottom flask containing a magnetic stirbar. The mixture was degassed for ten minutes with a nitrogen sparge before 10 g (0.012 mole) of [5] was added. The reaction mixture was then heated to 60° C. for two hours when TLC analysis indicated that conversion was complete. After cooling to room temperature, 30 mL of distilled water was added to help precipitate the product, which was collected by filtration and washed with methanol to yield 5.37 g of [6] (73% yield). Example 15 Synthesis of [6] from [5] and Gaseous Hydrogen Chloride. Ligand precursor [2] (84 g, 0.477 mole), [5] (161 g, 0.190 mole), and 1.6 L of methylene chloride were added to a dry round-bottom flask containing a magnetic stirbar and degassed with a nitrogen sparge. Dry hydrogen chloride gas was then bubbled through the mixture for approximately ten seconds. After stirring for two hours, hydrogen chloride gas was again bubbled through the mixture for approximately ten seconds. After a total of five hours of stirring, TLC analysis indicates complete conversion. The reaction mixture was concentrated by rotary evaporation before 500 mL of methanol was added to precipitate the product, which was isolated by filtration and washed twice with 100 mL of methanol to yield 97.5 g (82%) of [6]. Example 16 One-Pot Synthesis of [8] from Dichloro(1,5cyclooctadiene)ruthenium. Dichloro(1,5-cyclooctadiene)ruthenium (4.0 g, 0.014 moles), tricyclohexylphosphine (8.4 g, 0.030 moles), degassed triethylamine (2 mL), and degassed sec-butanol (60 mL) were combined in a pressure bottle under argon. The pressure bottle was purged with hydrogen gas, pressurized to 60 psi, and the mixture heated to 80° C. for 18 hours (the bottle was repressurized as needed to maintain 60 psi hydrogen). The reaction mixture was then allowed to cool down and the hydrogen gas was vented off. Degassed methanol (60 mL) was added to the orange slurry and the filtrate decanted off via stick filtration under argon to leave an orange solid in the bottle, which was washed with degassed methanol (60 mL). Degassed toluene (60 mL) was added to the orange solid and the orange slurry cooled to 0° C. Degassed 3-chloro-3-methyl-1-butyne (1.7 mL, 0.015 moles) was added dropwise via syringe at 0° C. The orange slurry progressively turned to a maroon slurry, while gas bubbled away. The mixture was stirred at room temperature for 2 hours after addition was complete. Ligand precursor [2] (18 g, 0.102 moles) was then charged and the mixture was heated to 80° C. and sparged with argon for 3 days (degassed toluene was added as needed). The brown slurry was allowed to cool to room temperature and a mixture of 30 mL methanol and 10 mL of concentrated hydrochloric acid was added in air with mixing. After string for 15 minutes at room temperature, the two phases were allowed to separate and the methanol phase was decanted off. Trituration with methanol (2×50 mL) gave a solid, which was collected on a frit and washed with more methanol (2×20 mL). The brown solid was then washed with hexanes (2×20 mL) and dried to give [8] (5.1 g, 0.085 moles) in 61% yield.

Chelating ligand precursors for the preparation of olefin metathesis catalysts are disclosed. The resulting catalysts are air stable monomeric species capable of promoting various metathesis reactions efficiently, which can be recovered from the reaction mixture and reused. Internal olefin compounds, specifically beta-substituted styrenes, are used as ligand precursors. Compared to terminal olefin compounds such as unsubstituted styrenes, the beta-substituted styrenes are easier and less costly to prepare, and more stable since they are less prone to spontaneous polymerization. Methods of preparing chelating-carbene metathesis catalysts without the use of CuCl are disclosed. This eliminates the need for CuCl by replacing it with organic acids, mineral acids, mild oxidants or even water, resulting in high yields of Hoveyda-type metathesis catalysts. The invention provides an efficient method for preparing chelating-carbene metathesis catalysts by reacting a suitable ruthenium complex in high concentrations of the ligand precursors followed by crystallization from an organic solvent.

BACKGROUND OF THE INVENTION The present invention relates to a method for the preparation of an organopolysiloxane or, more particularly, to a method for the preparation of an organopolysiloxane having tetrafunctional siloxane units and containing little amount of residual alkoxy groups so as to be useful as a reinforcing agent of silicone rubbers. Among various types of organopolysiloxanes, those soluble in organic solvents and consisting of monofunctional organosiloxy units represented by the general unit formula R 3 SiO 0 .5, in which R is a hydrogen atom or a monovalent hydrocarbon group, referred to as the M units hereinbelow, and tetrafunctional siloxane units of the formula SiO 2 , referred to as the Q units hereinbelow, are widely used in the art of silicone products, for example, as a reinforcing agent of silicone rubbers. Such an organopolysiloxane consisting of the M units and Q units is prepared, for example, by the method disclosed in U.S. Pat. Nos. 2,676,182 and 2,814,601, in which a water-soluble basic silicate such as sodium orthosilicate is converted into a silicic acid oligomer by the addition of hydrochloric acid or sulfuric acid followed by the reaction with a trialkyl chlorosilane. This method, however, has several problems as an industrial process because, since the silicic acid oligomer is relatively unstable, difficulties are encountered in the control of the molecular weight distribution in the organopolysiloxane product so that the molar ratio of the M units and the Q units in the organopolysiloxane product cannot be always consistent with the target molar ratio. In addition, since the waste water coming from the process necessarily contains a large amount of the waste acid used for the neutralization of the starting basic silicate as well as the hydrochloric acid produced as a by-product in the reaction of the trialkyl chlorosilane and also a large amount of an alcohol admixed with the reaction mixture with an object of stabilization of the reaction mixture, a large cost is required for the disposal of the waste water in order not to cause the problem of environmental pollution. When the waste water contains hydrochloric acid in a substantial concentration, in particular, the hydrogen chloride gas emitted therefrom is very harmful against human health with a strong irritating odor and strong corrosion is unavoidable on the apparatuses and pipe lines as well as other auxiliary instruments in the manufacturing plant so that they must be constructed by using highly corrosion-resistant but very expensive materials in addition to the disadvantage of large man power and very high cost required for the maintenance of the plant. Alternatively, the organopolysiloxane of this type can be prepared by the method taught in U.S. Pat. No. 2,857,356, in which an alkyl silicate and a trialkyl chlorosilane are subjected to cohydrolysis in the presence of hydrochloric acid, or by the method taught in Japanese Patent Kokai No. 61-195129, in which an alkyl silicate or a partial hydrolysis product thereof is added dropwise to a trialkyl chlorosilane in the presence of hydrochloric acid. As compared with the first described method, these methods have an advantage because the molar ratio of the M units and the Q units or the molecular weight distribution in the organopolysiloxane product can be controlled relatively easily while they have disadvantages that measures for the disposal of waste water and against the adverse effects of toxic and corrosive hydrochloric acid must be undertaken likewise as in the above described method since a large amount of hydrochloric acid must be added to the reaction mixture in addition to the hydrochloric acid produced by the reaction or the alcohol admixed in the reaction mixture. At any rate, these known methods are each industrially disadvantageous because a large volume of acid-containing waste water must be safely disposed and the productivity is low with a relatively low yield of the organopolysiloxane product per unit reaction volume as a consequence of the use of a large volume of organic solvents as a hydrolysis aid. When an organopolysiloxane containing a large amount of the Q units or, in particular, having the molar ratio of the M units to the Q units not exceeding 2 is desired, it is a rather difficult matter to adequately control the reaction so as to obtain an organopolysiloxane having the molar ratio of the units and molecular weight distribution exactly controlled as desired. Furthermore, difficulties are encountered in the preparation of an organopolysiloxane having a controlled amount of the silanol groups or alkoxy groups with good reproducibility. As a measure to dissolve the above described disadvantages, accordingly, a method is proposed in Japanese Patent Kokai No. 63-256628, in which an organosilane or an organosiloxane is reacted with an alkyl silicate or a partial hydrolysis product thereof in the presence of a sulfonic acid group-containing compound and/or phosphonitrile chloride as a catalyst. This method has advantages that control of the molar ratio of the M units to the Q units is relatively easy and no hydrochloric acid is produced as a by-product of the reaction. This method, however, is not free from the disadvantages that, since the reaction is conducted under atmospheric pressure, residual amount of the alkoxy groups must be removed by the addition of an excess amount of water taking a long reaction time during which gelled materials are sometimes formed in the reaction mixture resulting in very poor filtrability of the mixture with a greatly decreased productivity. When such a measure is not undertaken to leave a large amount of the residual alkoxy groups in the product, the applicability of such an organopolysiloxane product as a reinforcing agent of silicone rubbers would be low because no sufficient reinforcing effect can be obtained therewith and the mechanical strengths of the silicone rubber compounded with such an organopolysiloxane would be subject to gradual degradation in the lapse of time. SUMMARY OF THE INVENTION The present invention accordingly has an object to provide a novel and efficient method for the preparation of an organopolysiloxane comprising the Q units without the problems and disadvantages in the above described prior art methods. Thus, the method of the present invention for the preparation of an organopolysiloxane containing the tetrafunctional siloxane units comprises the steps of: (a) mixing an alkyl silicate or a partial hydrolysis product thereof as a first reactant with an organosilane compound represented by the general formula R.sub.a SiX.sub.4-a, (I) in which R is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group, X is an alkoxy group or a hydroxyl group and the subscript a is 1, 2 or 3, or an oligomeric organosiloxane compound consisting of the siloxane units represented by the general unit formula R.sub.b SiO.sub.(4-b)/2, (II) in which R has the same meaning as defined above and the subscript b is 1, 2 or 3, as a second reactant to form a mixture; and (b) heating the mixture, in a pressurizable reaction vessel, in the presence of water and a sulfonic acid group-containing compound or phosphonitrile chloride as a catalyst at a temperature higher by at least 10° C. than the boiling point of the mixture under atmospheric pressure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As is described above, the scope of the inventive method consists in the reaction conditions in which a mixture of an alkyl silicate or a partial hydrolysis product thereof with an organosilane or organosiloxane compound is heated, in a closed pressurizable reaction vessel, in the presence of water and a specific catalyst at a temperature higher by at least 10° C. than the boiling point of the mixture under atmospheric pressure. This method is advantageous because addition of an alcohol to the reaction mixture for stabilization is not necessary and almost no gelled material is formed in the mixture during the reaction without decreasing the filtrability of the reaction mixture after completion of the reaction in addition to the unexpected advantage that the content of the residual alkoxy groups in the organopolysiloxane product can be greatly decreased. One of the reactants in the reaction according to the inventive method is, on one hand, is an organosilane compound represented by the general formula R a SiX 4-a , in which R is a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group exemplified by alkyl groups such as methyl, ethyl, propyl and butyl groups, cycloalkyl groups such as cyclohexyl group, alkenyl groups such as vinyl and allyl groups and aryl groups such as phenyl and tolyl groups as well as those substituted hydrocarbon groups such as chloromethyl, 3,3,3-trifluoropropyl and 2-cyanoethyl groups obtained by replacing a part or all of the hydrogen atoms in the above named unsubstituted hydrocarbon groups with halogen atoms, cyano groups and the like, X is an alkoxy or hydroxy group and the subscript a is 1, 2 or 3. Examples of suitable organosilane compounds include trimethyl methoxy silane, trimethyl ethoxy silane, vinyl dimethyl methoxy silane, vinyl dimethyl ethoxy silane, dimethyl methoxy silane, dimethyl ethoxy silane, dimethyl dimethoxy silane, dimethyl diethoxy silane, vinyl methyl dimethoxy silane, vinyl methyl diethoxy silane and the like though not particularly limitative thereto. When the M units are essential in the organopolysiloxane product, the subscript a in the general formula should be 3 so that the organosilane compound is monofunctional having, in a molecule, only one group denoted by X as is the case in trimethyl methoxy silane. Another reactant compound alternative to the above described organosilane compound is an oligomeric organosiloxane compound consisting of at least two organosiloxane units each represented by the general unit formula R b SiO.sub.(4-b)/2, in which R has the same meaning as defined above for the organosilane compound and the subscript b is 1, 2 or 3. Two kinds or more of different organosiloxane units can be contained in a molecule of the organosiloxane compound. Examples of suitable oligomeric organosiloxane compounds include hexamethyl disiloxane, 1,1,3,3-tetramethyl-1,3-divinyl disiloxane, 1,1,3,3-tetramethyl disiloxane, octamethyl cyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinyl cyclotetrasiloxane and the like though not particularly limitative thereto. These oligomeric organosiloxane compounds can be used either singly or as a combination of two kinds or more according to the desired siloxane constitution in the organopolysiloxane product. When the desired organopolysiloxane product should contain the M units, for example, an organosiloxane comprising the monofunctional siloxy units RSiO 0 .5 should be used as the reactant such as hexamethyl disiloxane. When difunctional siloxane units are desired in the organopolysiloxane product, it is convenient to formulate the starting reaction mixture with a cyclic organosiloxane oligomer such as the above mentioned octamethyl cyclotetrasiloxane and 1,3,5,7-tetramethyl-1,3,5,7-tetravinyl cyclotetrasiloxane. It is optional to use the above described organosilane compound and the organosiloxane compound in combination according to need. The other reactant to be reacted with the above described organosilane or oligomeric organosiloxane compound in the reaction mixture is an alkyl silicate exemplified by methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and the like or a partial hydrolysis product thereof such as so-called polymethyl silicate, polyethyl silicate, polypropyl silicate and the like. The mixing ratio of the above described organosilane compound and/or organosiloxane compound as the second reactant to the alkyl silicate or partial hydrolysis product thereof as the first reactant should be adequately selected depending on the desired molar ratio of the M units to the Q units in the organopolysiloxane product. The catalyst used for promoting the reaction according to the inventive method is a sulfonic acid group-containing compound or phosphonitrile chloride. Examples of suitable compounds having a sulfonic acid group --SO 3 H include sulfuric acid, fuming sulfuric acid, methane sulfuric acid, sulfuric anhydride, p-toluene sulfonic acid and trifluoromethane sulfonic acid as well as a certain solid compound having a sulfonic acid group. It is optional to use a sulfonic acid group-containing compound and phosphonitrile chloride in combination according to need. The amount of the catalyst compound added to the reaction mixture is very small and can be much smaller than the amount of hydrochloric acid used as a catalyst in the conventional method. Though dependent on the desired velocity of the reaction, the amount of the catalyst added to the reaction mixture is usually in the range from 0.001 to 3% by weight based on the total amount of the organosilane compound or organosiloxane compound and the alkyl silicate or a partial hydrolysis product thereof. If necessary, the reaction mixture can be admixed with a small amount of an organic solvent including alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol and the like, aliphatic hydrocarbons such as n-hexane and the like and aromatic hydrocarbons such as benzene, toluene, xylene and the like. The method of the present invention is conducted by introducing the above described organosilane or oligomeric organosiloxane compound, alkyl silicate or a partial hydrolysis product thereof, water and catalyst into a pressurizable reaction vessel to form a reaction mixture and heating the reaction mixture in the closed reaction vessel up to a temperature higher by at least 10° C. or, preferably, by at least 20° C. than the boiling point of the reaction mixture under normal pressure to produce a super-atmospheric pressure which is preferably in the range from 1 to 10 kg/cm 2 G. When the reaction is undertaken under normal pressure, the reaction temperature is determined naturally by the boiling point of the mixture under normal pressure while, when the reaction is undertaken under pressurization, the reaction temperature is increased corresponding to the pressure so that the reaction can be accelerated so much. As is mentioned before, the reaction of the inventive method is carried out in the presence of water so that the reaction mixture must contain water in a controlled amount. The amount of water added to the reaction mixture should be in the range from 0.6 to 1.5 moles per mole of the alkoxy groups in the alkyl silicate or a partial hydrolysis product thereof and in the alkoxy-containing silane compound, if used. When the amount of water is too small, a large amount of the alkoxy groups in the starting reactants would remain unreacted while, when the amount of water is increased to exceed the above mentioned upper limit, no further influences are caused on the contents of the residual alkoxy groups and hydroxy groups and on the molecular weight of the organopolysiloxane product. Namely, the amount of water in the reaction mixture as well as the reaction temperature and reaction time would determine the contents of the residual alkoxy groups and hydroxy groups as well as the molecular weight of the SiO 2 unit-containing organopolysiloxane product. The reaction mixture can optionally be admixed with an organic solvent according to need. In practicing the method of the present invention by reacting the above defined organosilane or organosiloxane compound and an alkyl silicate or a partial hydrolysis product thereof in the presence of a specific catalytic compound and water under pressurization, the molar ratio of the M units to the Q units in the organopolysiloxane product is just the same as the molar ratio in the starting reaction mixture consisting of the organosilane or oligomeric organosiloxane compound providing the M units and the alkyl silicate or a partial hydrolysis product thereof providing the Q units. When the molar ratio of the M units to the Q units is smaller than 2, in particular, the advantage of the inventive method is so remarkable that the desired organopolysiloxane product, of which the molar ratio of the units can be exactly determined by the formulation of the reactant compounds in the starting reaction mixture, can be obtained in a much higher yield than in the conventional methods with a greatly decreased loss of the M units. Further, the amount of residual alkoxy groups and the amount of hydroxy groups can be controlled by the adjustment of the amount of the alkyl silicate or a partial hydrolysis product thereof in the reaction mixture, amount of the catalytic compound added to the reaction mixture, reaction pressure and reaction temperature so that the inventive method has great versatility for the preparation of various kinds of different organopolysiloxanes within a much shorter reaction time than in the conventional methods. In addition, formation of gelled matter can be almost completely prevented in the inventive method so that the reaction mixture after completion of the reaction retains good filtrability not to adversely influence the productivity. Still more advantageously, the inventive method is free from the problems of corrosion of the apparatuses and waste water disposal because no hydrogen chloride is formed in the reaction mixture as a by-product and addition of an alcohol is not required. In the following, the method of the present invention is described in more detail by way of examples and comparative examples. EXAMPLE 1 Into a pressure-resistant glass flask of 1 liter capacity equipped with a stirrer, thermometer, pressure gauge, dropping tube of 100 ml capacity and safety valve were introduced 130 g (0.8 mole) of hexamethyl disiloxane, 234.4 g of a partial hydrolysis product of tetramethoxy silane (Methyl Silicate 51, a product by Tama Chemical Co.) corresponding to 2 moles of SiO 2 units and 3 g of methane sulfonic acid to form a reaction mixture and 68 g (3.8 moles) of water were taken in the dropping tube. The water in the dropping tube was added dropwise over a period of about 10 minutes into the reaction mixture in the flask which was under agitation at a temperature of 20°±1° C. so that the temperature of the reaction mixture was increased to 64° C. After completion of the dropwise addition of water into the mixture in the flask, the mixture was further heated up to 100° C. and agitated at this temperature for 5 hours during which the pressure inside the flask was kept constant at 2.3 to 2.4 kg/cm 2 G. Thereafter, the flask was cooled to room temperature and released to open atmosphere. The mixture in the flask was transferred into another flask equipped with a condenser and, after neutralization with addition of a small amount of sodium hydrogencarbonate, admixed with toluene and the mixture was subjected to azeotropic distillation to remove the methyl alcohol formed as a by-product of the reaction and remaining amount of water leaving a toluene solution of the organopolysiloxane as the product. The content of the non-volatile matter in this toluene solution was adjusted to 50% by weight with addition of a calculated amount of an additional portion of toluene. This toluene solution had a viscosity of 3.90 centistokes at 25° C. The thus obtained organopolysiloxane could be expressed by the average unit formula of [(CH 3 ) 3 SiO 0 .5 ] 0 .8 [SiO 2 ] corresponding to a molar ratio of the M units to the Q units of 0.8. The content of residual methoxy groups in this organopolysiloxane was 0.052 mole per 100 g. The yield of this organopolysiloxane was 92.8% of the theoretical value. The toluene solution thereof in a concentration of 50% had good filtrability corresponding to a filtering time of 89 seconds taken for the filtration of 100 g of the solution through a filter paper of Toyo 5A grade. The conditions of this filtration test included: thickness of the filter paper 0.22 mm; minimum diameter of retained particles 7 μm; collecting efficiency 75%; effective area for filtration 150 cm 2 ; pressure difference 2 kg/cm 2 ; and temperature 25° C. COMPARATIVE EXAMPLE 1-1 The procedure was substantially the same as in Example 1 described above except that the reaction, which was performed in Example 1 in a closed pressure-resistant flask at 100° C., was performed in an open flask under reflux where the temperature of the reaction mixture in the flask was 64° to 67° C. The reaction mixture after completion of the reaction was treated also in the same manner as in Example 1 to prepare a toluene solution of the organopolysiloxane product in a concentration of 50% by weight, which had a viscosity of 2.81 centistokes at 25° C. The organopolysiloxane thus obtained could be expressed by the same average unit formula as the product obtained in Example 1 to give the molar ratio of the M units to the Q units of 0.8. However, the organopolysiloxane contained 0.145 mole of the residual methoxy groups per 100 g. COMPARATIVE EXAMPLE 1-2 The procedure was substantially the same as in Comparative Example 1-1 excepting extension of the reaction time under reflux at 64° to 67° C. up to 50 hours. At a moment after 20 hours of the reaction, the organopolysiloxane in the reaction mixture was analyzed to find that the content of the residual methoxy groups was 0.122 mole per 100 g. After 50 hours of the reaction, the reaction mixture was treated in the same manner as in Example 1 to prepare a toluene solution containing 50% by weight of the organopolysiloxane product, which had a viscosity of 2.90 centistokes at 25° C. The yield of the organopolysiloxane product was 81.9% of the theoretical value. The organopolysiloxane had a molar ratio 0.8 of the M units to the Q units but the content of the residual methoxy groups therein was 0.121 mole per 100 g indicating that extension of the reaction time over 20 hours had almost no effect of decreasing the content of the residual methoxy groups. COMPARATIVE EXAMPLE 1-3 A 100 g portion of the 50% by weight toluene solution of the organopolysiloxane prepared in Comparative Example 1-2 was admixed with 1 g of methane sulfonic acid and 10 g of water and heated under reflux for 20 hours at a temperature of 90° to 105° C. with an object to promote hydrolysis of the residual methoxy groups and to increase the molecular weight of the organopolysiloxane to such an extent as to be equivalent to that in Example 1. Thereafter, the mixture was subjected to azeotropic distillation to remove water and methyl alcohol until the boiling point was increased up to 110° C. and the content of the non-volatile matter therein was again adjusted to 50% by weight by the addition of toluene followed by filtration. This solution had a viscosity of 3.02 centistokes at 25° C. and the content of residual methoxy groups was 0.093 mole per 100 g of the solid content. The yield of the organopolysiloxane was 76.8% of the theoretical value. The filtrability of the 50% solution corresponded to 548 seconds of the filtering time as measured in the same manner as in Example 1. EXAMPLE 2 Into the same pressurizable flask as used in Example 1 were introduced 114 g (0.7 mole) of hexamethyl disiloxane, 37 g (0.2 mole) of 1,1,3,3-tetramethyl-1,3-divinyl disiloxane, 300 g of a partial hydrolysis product of tetraethoxy silane (Ethyl Silicate 40, a product by Colcote Co.) corresponding to 2 moles of SiO 2 units and 5 g of sulfuric acid to form a reaction mixture along with filling of the dropping tube with 88 g (4.9 moles) of water. The reaction mixture in the flask was agitated and kept at a temperature of 20°±1 ° C. and water in the dropping tube was added dropwise thereinto taking 5 minutes so that the temperature of the reaction mixture in the flask was increased up to 67° C. After completion of the dropwise addition of water, the flask was closed and the reaction mixture was agitated for 5 hours at a temperature of 115° C. to effect the reaction. The pressure inside the flask was 3.1 to 3.3 kg/cm 2 G throughout the reaction. The reaction mixture after the above mentioned reaction time was treated in the same manner as in Example 1 to prepare a toluene solution containing 50% by weight of the non-volatile matter, which had a viscosity of 3.10 centistokes at 25° C. Analysis of the non-volatile matter indicated that the product was an organopolysiloxane expressed by the average unit formula of [(CH 2 ═CH)(CH 3 ) 2 SiO 0 .5 ] 0 .2 [(CH 3 ) 3 SiO 0 .5 ] 0 .7 [SiO 2 ] corresponding to the molar ratio of the M units to the Q units of 0.9 and the content of residual ethoxy groups was 0.057 mole per 100 g of the non-volatile matter. COMPARATIVE EXAMPLE 2 The formulation of the reaction mixture was the same as in Example 2 described above and the reaction mixture after completion of dropwise addition of water was heated in an open flask for 50 hours with agitation under reflux. The temperature of the reaction mixture was 76° to 78° C. throughout the reaction. The reaction mixture after the reaction was treated in the same manner as in Example 1 to prepare a toluene solution containing 50% by weight of the non-volatile matter, which had a viscosity of 2.44 centistokes at 25° C. Analysis of the organopolysiloxane as the product indicated that the organopolysiloxane had a composition corresponding to the molar ratio of the M units to the Q units of 0.9 but the content of residual ethoxy groups was 0.143 mole per 100 g of the non-volatile matter. EXAMPLE 3 Into the same pressurizable flask as used in Example 1 were introduced 243.6 g (1.5 moles) of hexamethyl disiloxane, 150 g (1.0 mole) of tetramethoxy silane and 5 g of methane sulfonic acid to form a reaction mixture and the dropping tube was filled with 50 g (2.8 moles) of water. The water in the dropping tube was added dropwise taking 2 hours into the reaction mixture in the flask which was chilled and kept at a temperature of -10°±1° C. by using a cooling medium. After completion of the dropwise addition of water, the flask was closed and the reaction mixture in the flask was agitated for 5 hours at a temperature of 120° C. to effect the reaction. The pressure inside the flask was in the range from 5.5 to 5.8 kg/cm 2 G throughout the reaction. The reaction mixture after the above mentioned reaction time was treated in the same manner as in Example 1 to prepare a toluene solution containing 50% by weight of the non-volatile matter. The organopolysiloxane thus obtained had a viscosity of 14.6 centistokes at 25° C. Analysis of the solid matter as the product indicated that it was an organopolysiloxane expressed by the average unit formula of [(CH 3 ) 3 SiO 0 .5 ] 3 .0 [SiO 2 ] corresponding to the molar ratio of the M units to the Q units of 3.0 and the content of the residual methoxy groups was 0.57 mole per 100 g of the non-volatile matter. EXAMPLE 4 Into the same pressure-resistant flask as used in Example 1 were introduced 17.2 g (0.05 mole) of 1,3,5,7-tetramethyl-1,3,5,7-tetravinyl cyclotetrasiloxane, 14.8 g (0.05 mole) of octamethyl cyclotetrasiloxane, 152 g (1.0 mole) of tetramethoxy silane and 5 g of methane sulfonic acid to form a reaction mixture which was heated in the closed vessel at 110° C. for 5 hours under agitation. Thereafter, the reaction mixture was cooled to 20° C. and admixed with 65.0 g (0.4 mole) of hexamethyl disiloxane followed by dropwise addition of 50 g (2.8 moles) of water through the dropping tube taking 5 minutes. The reaction vessel was again closed and the reaction mixture in the flask was heated up to 120° C. where agitation was continued for 5 hours. The pressure inside the flask was 4.8 to 5.3 kg/cm 2 G throughout this reaction time. The reaction mixture was cooled to room temperature and treated in the same manner as in Example 1 to prepare a toluene solution containing 50% by weight of the non-volatile matter, which had a viscosity of 2.98 centistokes at 25° C. Analysis of the non-volatile matter thus obtained indicated that this product was an organopolysiloxane expressed by the average unit formula of [(CH 3 ) 3 SiO 0 .5 ] 0 .8 [(CH 3 ) 2 SiO] 0 .2 [[(CH 2 ═CH)(CH 3 )SiO] 0 .2 [SiO 2 ] and the content of the residual methoxy group was 0.059 mole per 100 g of the non-volatile matter.

An efficient and economically advantageous method is proposed for the preparation of an organopolysiloxane comprising tetrafunctional siloxane units, i.e. Q units, and, typically, monofunctional siloxy units, i.e. M units, and useful as a reinforcing agent in silicone rubbers. The method comprises the steps of: mixing the reactants for providing the Q and M units, such as ethyl orthosilicate and trimethyl methoxy silane, in a desired molar ratio; and heating the mixture at a temperature higher by at least 10° C. than the boiling point of the mixture under normal pressure in a closed vessel in the presence of water and a catalyst such as a sulfonic acid group-containing compound. In addition to the greatly shortened reaction time and remarkably decreased contents of residual alkoxy groups and gelled matter in the product, the method is advantageous also in respect of the absence of the problems caused by the disposal of the waste water as well as the corrosiveness of hydrogen chloride unavoidably produced in the conventional prior art methods.

CLAIM OF PRIORITY This application claims priority as a continuation in part application of U.S. patent application Ser. No. 12/353,401 filed on Jan. 14, 2009; which is a continuation-in-part application of U.S. patent application Ser. No. 10/513,512 having a 371(c) date of Jun. 20, 2005 (submitted to the USPTO on Nov. 4, 2004); which is a 371 of PCT/IL2003/000363, filed on May 5, 2003; which claims priority to Israeli patent application serial number 149499, filed on May 6, 2002. FIELD OF THE INVENTION This invention relates to a method for the preparation of concentrated solutions of stabilized hypobromites. This invention also relates to stabilized solutions of hypobromites obtained by the process of this invention. BACKGROUND OF THE INVENTION Hypobromous acid is one of the most potent sanitizers among the oxidizing halogenated compounds. Since it is a weaker acid than hypochlorous acid (pK=8.8 at 25° C.), it is predominant at pH higher than 9. Alkaline hypobromites can be prepared at low temperature, with good yield, if an excess of hydroxide is provided. A supersaturated solution can be prepared at 10° C., if 90% of the equivalent amount of bromine is fed to a 10 N solution of NaOH or KOH. The pentahydrate NaBrO.5H 2 O begins to precipitate at −3° C., and keeps precipitating at lower temperatures, while the heptahydrate begins to precipitate at −7° C., and keeps precipitating at lower temperatures. However, the precipitation is slow. This mode of operation enables the preparation of MOBr solution (M=Na, K), but these are not stable enough for practical and commercial application. Concentration increase of the MOBr has a beneficial effect on the stability because of the simultaneous decrease of water concentration Hypobromites, e.g. sodium hypobromite, can also be prepared from the reaction of bromides with an oxidant, e.g., chlorine or hypochlorite. The reaction with hypochlorite has the disadvantage of yielding equivalent amounts of NaOBr and NaCl. Since the NaOCl solutions themselves contain NaCl in equivalent amount with NaOCl, and mostly contain at most 15.8 wt % NaOCl, the obtainable concentration of NaOBr is relatively low. The strong oxidizing potential of the hypobromous acid and hypobromites made them very difficult to stabilize. Several classes of stabilizers, among them amides, amines, sulfonamides, melamine, sulfamic acid, cyanuric acid, and hydantoins, have been suggested in the prior art. However, amides and amines are generally oxidized by the hypobromites. Urea is decomposed down to nitrogen and other amides are transformed to amines that in turn can be oxidized to nitrogen. Sulfamic acid and its salts have been mentioned as stabilizers, being stable to the attack of hypochlorous and hypobromous acids. The latter react at low temperatures with the alkali salts of sulfamic acid, affording chloro- and bromoamidosulfonates XHN—SO 3 M (X=Halogen). However, some strong oxidants, among them chlorine and bromine, can attack the NH 2 function liberating nitrogen. U.S. Pat. No. 5,683,654 discloses a process which comprises preparing an aqueous solution of unstabilized alkali or alkaline earth metal hypobromite by mixing and reacting the corresponding hypochlorite with a water-soluble bromide ion source and stabilizing the result with an aqueous solution of an alkali metal sulfamate. U.S. Pat. Nos. 5,795,487 and 5,942,126 disclose essentially the same process. U.S. Pat. No. 6,037,318 describes a process for the manufacture of alkaline bleaching compositions which comprises three steps: a) admixing a source of sodium hypochlorite and an amino compound which may be sulfamic acid, to form a pre-bromine admixture; b) adding to the mixture a source of bromine; and c) adjusting the pH of the resulting mixture to at least 13. However, since hypochlorite solutions generally contain chlorides in an equivalent amount with hypochlorites, the resulting mixtures contain large amounts of sodium chloride. Further, since the stabilizer, e.g., sulfamic acid, and the hypochlorite are mixed before the addition of a bromine source, the efficiency of the stabilizer is decreased, because it reacts with the hypochlorite. The stabilized solution has a low NaOBr concentration because of the low concentration of the starting NaOCl solution. DE 3398850 discloses stabilizing solutions of sodium hypochlorite with a stabilizer which may be the sodium salt of amidosulfonic acid. It does not teach the preparation of hypobromite solutions. U.S. Pat. No. 6,068,861 describes a process of making a concentrated liquid biocide formulation, in which bromine chloride and an alkali metal salt of sulfamic acid are mixed. Bromine chloride is difficult to handle and tends to dissociate to bromine and chlorine. It is not a commercial product and must be manufactured by using special skills and expensive installations for keeping it in liquid phase under pressure. It is a purpose of this invention to provide a method for obtaining stabilized solutions which contain high concentrations of alkali hypobromites. It is another purpose of the invention to provide such solutions in which bromine is fed as such and not through a more complex source of bromine. It is a further purpose of this invention to provide such a process that provides hypobromite solutions having an amount of active halogen, expressed as available chlorine, that is higher than that of any solution prepared according to the prior art. It is a still further purpose of this invention to provide a sanitation method for bodies of water, such as industrial water in cooling towers, pulp and paper waste and the like, in the pH range of 5-10, by feeding the hypobromite solution prepared according to the process of the invention, so that the proper active HOBr concentration (expressed as available chlorine) is achieved. Other purposes and advantages of the invention will appear as the description proceeds. SUMMARY OF THE INVENTION The invention provides a process for the preparation of stabilized aqueous solutions of high concentration hypobromites, comprising the steps of: a) contacting a concentrated alkali hydroxide aqueous solution with bromine, in a hydroxide-bromine equivalent ratio from 2:1 to 3:1; b) allowing the mixture to react at a temperature from −7 to 15° C., preferably from −5 to 10° C., thereby obtaining a solution of unstabilized alkali hypobromite, and alkali bromide; c) adding to said solution of step b) an aqueous solution of a sulfamic compound selected from the group consisting of sulfamic acid and soluble sulfamic acid salts, at a molar ratio of sulfamate to hypobromite from 1:1 to 2:1, and preferably between 1.2:1 and 1.5:1, at a temperature from −5° C. to 10° C., whereby to form stabilized hypobromite solution containing alkali bromide; and d) admixing to said stabilized hypobromite solution an oxidant to oxidize said alkali bromide, thereby obtaining a stabilized aqueous solution of high concentration hypobromite; wherein said stabilized aqueous solutions of high concentration hypobromites have at least 10 wt % hypobromites if expressed as NaBrO. The sulfamic compound is preferably sodium sulfamate. The hydroxide-bromine molar ratio is preferably not less than 2.2:1. In a preferred embodiment of the invention, the mixture of alkali hydroxide solution with bromine is allowed to react at a temperature of 0±5° C. Said oxidation process is preferably performed at a temperature of 0±5° C. The oxidant may be selected from the group consisting of sodium hypochlorite, calcium hypochlorite, chlorine, hydrogen peroxide, and oxone. Preferably, said oxidant is sodium hypochlorite having a concentration of at least 10.5% expressed as available chlorine. The sodium hypochlorite may be formed in situ from chlorine and sodium hydroxide. The process according to the invention may further comprise adding a sulfamate solution to said stabilized aqueous solution of high concentration hypobromite obtained in said step d), to a molar ratio of sulfamate to hypobromite not greater than 1.5:1. In one aspect, the process according to the invention may comprise on-line formation of high concentrated hypobromite at a site of needed use; the process may comprise forming a first liquid stream and a second liquid stream, wherein said first liquid stream comprises said stabilized hypobromite solution containing alkali bromide, and wherein said second liquid stream comprises said oxidant, the two streams meeting near the location of the intended use, thereby providing a high concentration hypobromite solution at said location. The invention provides a stabilized alkali hypobromite solution, preferably a sodium hypobromite solution, containing at least 8 wt % of sodium hypobromite, preferably at least 10 wt % sodium hypobromite, less than 1 wt % of sodium bromide, less than 7 wt % of sodium chloride, and at least 12 wt % of sodium sulfamate. Said stabilized sodium hypobromite solution preferably contains at least 15 wt % sodium hypobromite. The available chlorine of said solution is at least 6%, and preferably at least 9%. A stabilized alkali hypobromite solution according to the invention may comprise up to 15% of available chlorine. The stabilized, high concentration, alkali hypobromite solution according to the invention, preferably sodium hypobromite solution, is very useful for disinfection of industrial water in cooling towers, pulp and paper wastes and similar. The process of the invention comprises the following steps: a) contacting a concentrated alkali hydroxide aqueous solution with bromine, in a hydroxide-bromine equivalent ratio that is from 2:1 to 3:1 and is preferably not less than 2.2:1; b) allowing the mixture to react at a temperature from −5° C. to 10° C., preferably 0±5° C.; c) adding to the product of said reaction, which comprises unstabilized alkali hypobromite, a concentrated aqueous solution of a sulfamic compound, chosen from the group consisting of sulfamic acid and soluble sulfamic acid salts, so that a molar ratio of said acid or salt to hypobromite is from 1:1 to 2:1 and preferably about 1.5:1, at a temperature from −5° C. to 10° C. and preferably 0±5° C., whereby to form a stabilized hypobromite solution. The preferred sulfamic compound is sodium sulfamate. The aqueous solution obtained is free from alkali chloride. It contains, depending on the concentration of the sulfamic acid or sulfamate solution, an amount of active halogen, expressed as available chlorine, from 7 to 11.5 wt %, based on the weight of the whole solution and determined by iodometric titration. The solution prepared by the process defined hereinbefore, has a higher stability than the solution of the prior art, as will be specified later on. The preferred alkali hydroxide is sodium hydroxide. The solution according to the invention contains alkali bromide, preferably e.g. sodium bromide. Its alkali, e.g. sodium, chloride content is less than 1 wt % and its amount of available halogen, expressed as chlorine, is at least 7%. It further contains from 13 to 19 wt % of sulfamate anion. Said solution is an aspect of the present invention. Obviously, as being clear for anybody skilled in the art, these concentrations are given for a 100% yield; as obvious to the skilled in the art, somewhat lower yields are practically obtained, depending on the ability of the operator and precision of temperature and weight control. The yields actually achieved are usually between 96% and 98%. In another embodiment of the invention, said bromide can be further oxidized with a known oxidizer, e.g. sodium hypochlorite, oxone, calcium hypochlorite, chlorine, hydrogen peroxide, etc., at the same low temperature at which the alkali hydroxide has been allowed to react with bromine in the first stage of the process. Preferably, if sodium hypochlorite is used as oxidizer, it should have a concentration of at least 10.5%, preferably at least 12.5%, expressed as available chlorine. The hypochlorite can be formed in situ from chlorine and a hydroxide, e.g. sodium hydroxide. The hypobromite is thus obtained in an amount equivalent to that of the alkali bromide, e.g. sodium bromide. The newly formed hypobromite can be further stabilized by an addition of a concentrated sodium sulfamate solution at a molar ratio of sulfamate to hypobromite from 1:1 to 1.5:1 and preferably about 1.1:1, at a temperature from −5° C. to 10° C. and preferably 0±5° C. In another embodiment, the production of supplementary amount of NaOBr from the sodium bromide present in the stabilized bromine solution can be done on-line, at the site of the intended use, by pumping the sodium hypochlorite solution and the stabilized bromine solution at required flow rates and by contacting the two solutions at a distance before the site of use, such that at the site of use the two solutions have been mixed, and the reaction between the sodium hypochlorite and the sodium bromide has been complete. The newly formed sodium hypobromite adds to the existing one in the stabilized solution, and the resulting mixture is immediately contacted with the liquid to be disinfected. By this mode of use there is no need for more stabilizer since the hypobromite reacts immediately with the organic matter. This embodiment will be illustrated in the following example. The solution obtained after said further oxidation contains, depending on the oxidant used (oxone, TCCA, hydrogen peroxide, etc.) and on the amount and concentration of eventually added supplementary sodium sulfamate, contains at least at least 6 and up to 15% available chlorine, and stabilized high concentration alkali hypobromite, e.g. sodium hypobromite in a concentration of from about 9 wt % to about 23 wt %, less than 1 wt % of sodium bromide, less than 7 wt % and down to 0 wt % of alkali, e.g. sodium, chloride, and a corresponding amount of alkali sulfamate, e.g. sodium sulfamate. Preferably, sodium hypobromite in a stabilized high concentration aqueous solution is from about 10 to about 20 wt %. BRIEF DESCRIPTION OF THE DRAWING The above and other characteristics and advantages of the invention will be more readily apparent through the following examples, and with reference to the appended drawing, wherein: FIG. 1 . shows a schematic setup for the an on-line preparation of concentrated hypobromites solutions near the location of the desired use. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The following examples illustrate the invention without being limitative. The percentages given are all by weight. EXAMPLE 1 A concentrated hypobromite solution was prepared by contacting, under vigorous stirring, a mixture of 532.5 g of a concentrated aqueous NaOH solution (49.2 wt %) and 494 g water with 480 g bromine, while adding gradually so that the temperature is maintained at 0±5° C. The NaOH/bromine molar ratio was 2.2:1. A clear, dark yellow solution of unstabilized sodium hypobromite was obtained, which contained 23.2 wt % NaOBr and 20.5 wt % NaBr. In spite of the very high concentration and low temperature, no precipitation occurred due to the very high solubility of NaBr. To the above hypobromite solution, an aqueous solution of sodium sulfamate was added gradually, in order to keep the temperature between −5 to 10° C., preferably 0-5° C. The above said aqueous solution of sodium sulfamate was prepared by gradually adding at room temperature 401.7 g of an aqueous 49.2 wt % NaOH solution to 836.5 g of an aqueous slurry composed of 436.5 g sulfamic acid and 400 g water, was added to the. Alternatively, said sulfamate can be prepared by adding 36 g of a 49.2% NaOH solution to a solution of 535.5 g commercial sodium sulfamate in 666.7 g water. The molar ratio between Na sulfamate and NaOBr was somewhat greater than 1.5:1. The resulting solution (2745 g) contained 12.7 wt % stabilized NaOBr, 11.5 wt % NaBr (ca one mole per mole of NaOBr), and 19.5 wt % of sodium sulfamate. The amount of active halogen, expressed as available chlorine, determined by iodometry, was 7.5%. EXAMPLE 2 In a reactor provided with cooling jacket and mixing device, introduced was 500 g stabilized bromine solution prepared as described in Example 1. To this solution, cooled at 0-5° C., was added 377 g of a sodium hypochlorite commercial solution containing 11% sodium hypochlorite (expressed as available chlorine) that reacted with the NaBr present, forming NaOBr. The solution in the reactor (877 g) then contained ca 14.6% NaOBr, practically no NaBr, 4.6% NaCl and 10.9% sulfamate. The solution can be utilized as such but it is less stable on storage because the ratio between sulfamate and hypobromite is less than required. This solution contained 8.8% available halogen (as Cl 2 ). EXAMPLE 3 A more stable, but less concentrated, stabilized bromine solution was prepared by adding, at 0-10° C., to the mixture prepared as in Example 2, 222 g sodium sulfamate, prepared as in Example 1. The 1109 g solution thus obtained contained ca 11.5 wt % sodium hypobromite. In terms of available chlorine it contained ca 7% available chlorine. The molar ratio of sodium sulfamate to NaOBr in this solution was 1.5:1. EXAMPLE 4 The solution of Example 2 can be prepared and used without the addition of more sodium sulfamate by preparing the solution on-line, as close as possible to the use location. A schematic setup for the preparation of this solution is given in FIG. 1 . The two solutions, the 12.7% stabilized hypobromite and 11% hypochlorite are fed to the static mixer at a mass flow rate ratio of 1:0.754 (volumetric flow rate ca 1.1:1). Supposing that the amount of make-up to be disinfected added to the cooling tower is 20000 l/h, and that the amount of available chlorine required is 2.5 ppm the mass flow rates of the two solutions should be 323 and 244 g/h (222 and 203 ml/h) respectively. The resulting solution is directly fed to the cooling tower. Due to a short time period between mixing the two streams and the use of the mixture, the stability of the NaOBr until entering the cooling tower is sufficient. While a number of examples have been given by way of illustration, it should be understood that the invention can be carried out with many modifications, variations and adaptations, without departing from its spirit or exceeding the scope of the claims.

The invention provides stabilized concentrated aqueous solutions of alkali hypobromites, as well as a process for the preparation of said stabilized concentrated solutions at low temperatures, comprising reacting a concentrated alkali hydroxide aqueous solution with bromine, adding to the non-stabilized reaction product an aqueous solution of a sulfamic compound to stabilize the hypobromite, and oxidizing bromide to produce additional hypobromite.

NOTICE OF COPYRIGHTS AND TRADE DRESS A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever. BACKGROUND Field This disclosure relates to powder coating, and in particular to powder coating a glass item to block visible and nonvisible light from passing through the glass. Description of the Related Art Powder coating is a process for coating articles with a sprayed-on organic polymeric material or polymer resin in a powdered form. The powder is typically initially applied electrostatically to an article. The powder is then permanently adhered to the article by the application of heat. The heat causes the powder to melt, liquefy and coat the article. When the article cools, the powder coating cures. Powder coating is typically applied to metal articles such as fence posts, mail boxes, home appliances, patio furniture, bicycles, and other items. Powder coating is an alternative to paint. DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart of a method of powder coating glass items. FIG. 2 is a drawing showing an example arrangement of a system for powder coating glass items. DETAILED DESCRIPTION Systems and methods of powder coating glass to block light are described herein. The powder coating may be placed on glass windows to keep light out a desired amount. The powder coating may be placed on the external portion of glass storage container, jars and the like to keep light out a desired amount or to block all light having particular wavelengths. This may be beneficial for glass storage and dispending containers, jars, and the like used in transporting and storage of food items (for example, olive oil), alcoholic beverages, nail polish, polish, paint, and other items that spoil, become less effective, cure or become unusable for their intended purpose when exposed to light. With glass items, the number of powder coats and thickness of application may impede or block varying amounts of light. According to the systems and methods herein, complete blocking of light, blocking visible light, blocking nonvisible light, and/or blocking of desired wavelengths of light may be achieved. According to the systems and methods described herein, a chemically resilient powder coating of glass items may be achieved. That is, the powder coated items will resist and be impervious to certain harsh chemicals. For example, the resulting powder coated glass items will withstand fingernail polish and fingernail polish solvents such as acetone, butyl acetate and ethyl acetate. A flow chart of a method of powder coating glass items is shown in FIG. 1 . An example arrangement of a system for powder coating glass items is shown in FIG. 2 . This disclosure will refer to both of these drawings throughout. Generally, as described herein, to block light from passing through glass or into a glass article, two or three coats of powder are applied to a pre-heated glass article, and heat is used to cure the powder on the glass article. The powder initially adheres to the glass because of the temperature of the glass. Because of the choices of powder used for each of the powder coats, the coats of powder interact to block a desired amount of light having certain wavelengths. Because of the choices of powder used for each of the powder coats, the coats of powder interact to form a chemically resilient coating on the glass. The particles in the powder coats when applied to the glass article interact and/or crosslink to block light. The powders used have common characteristics of typical powder coatings used in the industry, with key characteristics in ranges or amounts to achieve the methods described herein. The powders are polyester and/or epoxy, or a combination thereof. In one embodiment the first powder is epoxy and the second powder is polyester. In one embodiment, the first powder has a particle size in the range from 20-30 μm, and the second powder has a particle size in the range from 30-35 μm. In one embodiment, the first powder has a particle size of 25 μm, and the second powder has a particle size of 30 μm. In addition, the second powder is solvent resistant and meets the ASTM D5402 double rub standard. Further, the first powder has properties that allow it to stay wet longer, that is remain in a gel state longer and to flow for a longer period of time. Pertinent characteristics of the first powder are: a melting point in the range of 176-194° F., and in one embodiment a melting point of 188.6° F.; a gel time of 260-300 seconds, and in one embodiment a gel time of 262 seconds; a specific gravity of 1.2-1.4 gr/cm 3 , and in one embodiment, a specific gravity of 1.3 gr/cm 3 . Other pertinent characteristics of the second powder are: a melting point in the range of 176-194° F., and in one embodiment a melting point of 188.6° F.; a gel time of 97-107 seconds, and in one embodiment a gel time of 102 seconds; and a specific gravity in the range of 1.36-1.46 gr/cm 3 and in one embodiment a specific gravity of 1.41 gr/cm 3 . Referring to FIG. 1 , as a preliminary step, first and second sprayers are loaded with powder or otherwise set up to spray glass articles, as shown in blocks 102 and 104 . This is shown in FIG. 2 , in which bucket or receptacle 240 is loaded with powder 242 , and sprayer 230 having handle 232 and nozzle 234 is attached or coupled with the powder 242 in the bucket by a hose 236 . In one embodiment, the sprayer may be hand operated. In another embodiment, the sprayer may operate in an automated way and/or be robotic. The sprayer moves or is moved vertically so as to evenly apply a spray of powder to the glass articles 210 on the rack 220 . The sprayer 230 may be moved to or move a desired horizontal distance from the glass articles to apply an optimum amount of powder. As another optional preliminary step, the glass articles may be prepared by dusting and/or washing with water, soap, and/or light acid, as shown in block 110 . As a further optional preliminary step, the glass articles 210 may be placed on a rack 220 having stems or branches 226 on which glass articles may be placed or attached. In one embodiment, the glass articles are bottles (large or small) in which stoppers or an internal blockage has been placed to both secure the bottle mouth and/or neck to the branches 226 and to keep powder from entering the inside of the bottles 210 . The rack 220 may be mobile by having wheels 224 attached to a base 222 of the rack 220 . The rack may be made out of a strong and resilient metal that can withstand the heat of the ovens described herein. According to the method, a first oven is preheated to a desired air temperature such that that air in the oven reaches and is maintained at the desired air temperature, as shown in block 112 . The oven may be a convection oven. In one embodiment, the preferred air temperature of the first oven is 425 degrees Fahrenheit. Other temperatures may be used that are within a range of 390 to 450 degrees Fahrenheit, so long as the appropriate glass temperature is reached in a desirable amount of time. This is discussed more below. A second oven is preheated to a desired air temperature, such that that air in the oven reaches and is maintained at the desired air temperature, as shown in block 114 . In one embodiment, the preferred air temperature of the second oven is 400 degrees Fahrenheit, while in another embodiment it is 450 degree Fahrenheit. Other temperatures may be used that are within a range of 390 to 450 degrees Fahrenheit, so long as the appropriate curing is achieved in a desired amount of time. This is discussed more below. A third oven is preheated to a desired air temperature such that that air in the oven reaches and is maintained at the desired air temperature, as shown in block 116 . In one embodiment, the preferred air temperature of the third oven is 400 degrees Fahrenheit. Other temperatures may be used that are within a range of 390 to 450 degrees Fahrenheit, so long as the appropriate curing is achieved in a desired amount of time. This is discussed more below. In one embodiment, one oven is used, and the oven temperature is changed accordingly prior to entry of the glass articles or powder coated glass articles. That is, the first oven, the second oven and the third oven may all be the same oven. Before any powder is applied to a glass article, the glass article is placed in an oven, and the glass article is heated at a first desired air temperature until the glass article reaches a first desired glass temperature and/or for a first set amount of time, as shown in block 120 . In one embodiment, the first air temperature is approximately 425 degrees Fahrenheit and the first glass temperature is approximately 350 degrees Fahrenheit. The glass article is removed from the oven, and, a first powder coating of the first powder is applied, as shown in block 130 . The first powder coating is applied to the glass articles while the glass is hot but in an area of a building or in room that is at what is commonly known as room temperature, for example, 66-79° F. The glass article is then placed in an oven where it is heated at a second air temperature for a second set time to reach a desired curing, as shown in block 140 . In one embodiment the second air temperature is 400 degrees Fahrenheit and the second set time is 10 minutes. The glass article may move through the oven on a conveyor belt or automated system that moves at, for example, five feet per minute. The glass article is removed from the second oven after or when the second time has been reached or has expired. The second powder coating of the second powder is then applied, as shown in block 150 . When the second powder coating is applied, it interacts with and reacts with the first powder coating. The second powder coating blocks holes in the first powder coating that may let light through. The particles of the second powder fit in between and merge with the particles of the first powder coat. This may be considered crosslinking of the particles of the two different powders. It is in this way the light blocking properties of the multiple coatings of powders form a light blocking coating on the glass article. The glass article having the first and second powder coats applied is then placed in an oven where it is heated at a third air temperature for a third set time to reach a desired curing, as shown in block 160 . In one embodiment the third air temperature is 400 degrees Fahrenheit and the third set time is 30 minutes or 40 minutes. The glass article is removed from the third oven after or when the third time has been reached or has expired. The article is then let to cool to room temperature. Cool down time may be 10 minutes. In one embodiment, the rack 220 is attached on its top to a vertical conveyor system that moves the rack and glass articles 210 through the oven at a set rate of speed. In this embodiment, the second air temperature is 450 degrees Fahrenheit and the glass articles move through the second oven at a rate of 5 feet per minute for 10 minutes. In another embodiment, the second air temperature is 400 degrees Fahrenheit and the glass articles move through the second oven at a rate of 5 feet per minute for 10 minutes. In one embodiment, an optional third coating of a third powder is applied. The third powder may have similar characteristics to the first two powders. The third coating may be considered an aesthetic coating as it is not needed to achieve the light blocking qualities described herein. The aesthetic coating may have a desired color or other aesthetic features such as matte, gloss, sparkles and the like. The glass article is then placed in an oven where it is heated at a fourth air temperature for a fourth set time to reach a desired curing. In one embodiment, the fourth air temperature is 400 degrees Fahrenheit and the fourth set time is 30 minutes. The glass article is removed from the oven after or when the fourth time has been reached or has expired. The article is then let to cool at and to room temperature. The resulting powder coated glass article blocks visible light and nonvisible light. The resulting powder coated glass article blocks light in the UVA, UVB and UVC spectrums. In one embodiment the resulting powder coated glass article blocks light in the range of 300 to 800 nanometer wavelength. In addition, the resulting powder coasted glass articles are impervious and/or resistant to harsh chemicals. CLOSING COMMENTS Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and procedures disclosed or claimed. Although many of the examples presented herein involve specific combinations of method acts, it should be understood that those acts may be combined in other ways to accomplish the same objectives. With regard to flowcharts, additional and fewer steps may be taken, and the steps as shown may be combined or further refined to achieve the methods described herein. As used herein, “plurality” means two or more. As used herein, a “set” of items may include one or more of such items. As used herein, whether in the written description or the claims, the terms “comprising”, “including”, “carrying”, “having”, “containing”, “involving”, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of”, respectively, are closed or semi-closed transitional phrases with respect to claims. Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. As used herein, “and/or” means that the listed items are alternatives, but the alternatives also include any combination of the listed items.

Systems and methods of powder coating glass to block light are described herein. The method includes preheating a glass item and applying two or three coats of powder, alternating with heating at desired temperatures and/or for a set time. The glass article may be a glass window or a container for holding items that must be stored or transported without being exposed to light.

BACKGROUND OF THE INVENTION 1. Technical Field of the Invention The present invention relates to a resolver unit which detects a rotational position, and a resolver using it, and more particularly to a resolver unit which has transformer windings, and in which the axial length is shortened, and a resolver using it. 2. Description of the Related Art FIG. 6 shows a related art resolver comprising transformer windings for a power supply. FIG. 6 is a fragmentary sectional view of the related art resolver having a cylindrical stator assembly, and a rotor assembly which is placed coaxially with the cylindrical stator assembly. In FIG. 6 , the resolver 100 comprises the cylindrical stator assembly 101 , the rotor assembly 102 which is placed coaxially with the stator assembly 101 , and a transformer portion 103 . The transformer portion 103 has an inner core 104 , and an outer core 105 which is placed coaxially with the inner core. A stator portion has a structure in which the outer core 105 and the stator assembly 101 are axially built in a cylindrical housing 106 . A rotor portion has a structure in which the inner core 104 and the rotor assembly 102 are axially built in a shaft 107 . In the transformer portion 103 , a winding of the inner core 104 is connected to a rotor winding of the rotor assembly 102 by a crossover wire. Winding portions of the resolver are coaxially placed. In order to prevent the shaft from being eccentric, therefore, two bearings 108 are placed with being axially separated from each other. In the example shown in FIG. 6 , the inner core 104 , the rotor assembly 102 , and the two bearings 108 are continuously disposed in the axial direction. Consequently, the axial length is prolonged, and the stator assembly 101 and the rotor assembly 102 which are cylindrically placed, and the inner core 104 and the outer core 105 have a complicated structure, thereby causing a problem that the whole resolver cannot be miniaturized. In order to shorten the axial direction, therefore, a disk type resolver or a flat type resolver has been proposed (for example, JP-A-8-136211 and JP-A-5-010779, hereinafter referred to “JPA'211” and “JPA'779” respectively). FIG. 7 is a sectional view of a related art flat type resolver which is described in below. In FIG. 7 , the stationary side has a stationary core 111 and a stationary sheet coil 113 . The stationary core 111 comprises a magnetic plate 112 which is made of a material having an excellent high-frequency iron loss characteristic, such as disk-like ferrite. The stationary sheet coil 113 is fixed to a side face of the magnetic plate 112 by an adhesive agent or the like. In the stationary sheet coil 113 , a primary winding 114 of a rotary transformer portion A, and a detection winding 115 of a signal generating portion B are formed from a flat plate-like conductor by a printed wiring produced with etching, printing, or a press work, and bonded to the front and rear faces of a disk-like insulating substrate made of polyimide. An insulating process using a polyimide resin or the like is applied over the surface of the conductor. The rotary side has a rotary core 116 and a rotary sheet coil 118 , and is fixed to a shaft 119 . The rotary core 116 is a disk-like core which is opposed to the stationary core 111 via an air gap, and comprises a magnetic plate 117 in the same manner as the stationary core 111 . The rotary core 116 is fixed to the shaft 119 at the center, and supported via a bearing 121 by a bracket 120 fixed to the stationary core 111 . The rotary sheet coil 118 is fixed to a side face of the magnetic plate 117 by an adhesive agent or the like. In the rotary sheet coil 118 , a secondary winding 122 of the rotary transformer portion A, and an exciting winding 123 of the signal generating portion B are similarly formed by a printed wiring, and bonded to the front and rear faces of a disk-like insulating substrate 124 made of polyimide. An insulating process using a polyimide resin or the like is applied over the surface of the conductor. In the case where the fixation of the stationary core 111 and the stationary sheet coil 113 , and that of the rotary core 116 and the rotary sheet coil 118 are conducted by an adhesive agent, the adhesive agent has a thickness of about 25 μm, and hence the magnetic air gap is increased. This causes the power consumption to be increased. The related art flat type resolver of FIG. 7 has the following problems. (1) In the case where the fixation of the stationary core 111 and the stationary sheet coil 113 , and that of the rotary core 116 and the rotary sheet coil 118 are conducted by an adhesive agent, the adhesive agent has a thickness of about 25 μm. Therefore, the stationary sheet coil 113 may be attached with being inclined with respect to the face of the stationary core 111 by a thick layer of the adhesive agent, or the rotary sheet coil 118 may be attached with being inclined with respect to the face of the rotary core 116 by a thick layer of the adhesive agent. In such a case, the gap between the rotary and stationary sides cannot be made uniform, and there is a problem in that the magnetic coupling characteristic between the rotary and stationary sides is distorted by a degree corresponding to the inclination. (2) The surface of each conductor is provided with the insulating process using a polyimide resin or the like. Therefore, the thickness of the resin layer on the conductor causes the gap between the rotary and stationary sides not to be uniformly formed, and the axial length between the rotary and stationary sides is prolonged. Consequently, there is a problem in that the magnetic coupling characteristic between the rotary and stationary sides is impaired. (3) The primary winding 114 of the rotary transformer portion A, and the detection winding 115 of the signal generating portion B are supported on the magnetic plate 112 , and the secondary winding 122 of the rotary transformer portion A, and the exciting winding 123 of the signal generating portion B are supported on the magnetic plate 117 . Magnetic members forming the magnetic path are restricted to only the magnetic plates 112 and 117 on the both sides. Therefore, the distance from the winding on one side to the magnetic plate on the other side is relatively long. When the number of rotations is decreased and the output power of the transformer is reduced, consequently, magnetic fluxes crossing the magnetic plates 112 and 117 are hardly produced. Hence, a magnetic path which forms magnetic fluxes effectively interlinking with the secondary winding 122 and the detection winding 115 is insufficient, and leakage magnetic fluxes are increased. Since each winding is formed from a flat plate-like conductor by a printed wiring produced with etching, printing, or a press work, the number of turns cannot be increased. Therefore, it is difficult to increase magnetic fluxes generated by the winding. Consequently, it has been requested to develop a resolver in which the axial length is shortened so as not to impair the magnetic coupling characteristic between the rotary and stationary sides, and a winding generates a large number of magnetic fluxes. JP-A-57-052639 (hereinafter referred to “JPA'639” shows an example which serves as a reference. FIG. 8 is a view showing the configuration of the example disclosed in JPA'639. In a resolver 130 of FIG. 8 , a rotary transformer 131 and a resolver body 132 are concentrically placed around a rotation shaft 133 with placing the rotary transformer in the inner side and the resolver body in the outer side, thereby reducing the thickness of the resolver 130 . A rotor portion 134 of the rotary transformer 131 is fixed to the rotation shaft 133 , and a stator portion 135 is fixed to an annular stator portion support member 138 which is inwardly projected from an end plate portion 137 of a case 136 . A rotor portion 139 of the resolver body 132 is fixed to a rotor portion support member 140 which is supported integrally by the rotation shaft 133 , and a stator portion 143 of the resolver body 132 is fixed to the case 136 . The rotor portion support member 140 comprises a disk portion 141 fixed to the rotation shaft 133 , and an annular portion 142 which is continuously disposed on the circumference of the disk portion 141 . (1) In the resolver of FIG. 8 , in the direction from the center axis to the radially outer side, the rotor portion 134 of the rotary transformer 131 disposed on the rotation shaft 133 , the stator portion 135 of the rotary transformer 131 disposed on the stator portion support member 138 , the rotor portion 139 of the resolver body 132 disposed on the rotor portion support member 140 , and the stator portion 143 of the resolver body 132 disposed on the case 136 are placed in this order. In this configuration, gaps are produced between the rotor portion 134 of the rotary transformer 131 and the stator portion 135 , between the stator portion support member 138 and the rotor portion support member 140 , and between the rotor portion 139 of the resolver body 132 and the stator portion 143 . These gaps are hardly kept to respective appropriate values because the number of the gaps is large. (2) In order to supply the electric power generated in the rotary transformer 131 to an exciting coil of the resolver body 132 , a coil winding of the rotor portion 134 of the rotary transformer 131 is connected to that of the rotor portion 139 of the resolver body 132 by a crossover wire. The crossover wire is extended along the rotor portion support member 140 . Since the length of the crossover wire is large, the crossover wire is susceptible to the wind pressure during rotation, and also to vibrations during rotation. Therefore, damage such as breakage easily occurs in the crossover wire. (3) In order to couple the rotor portion 139 of the resolver body 132 and the rotor portion 134 of the rotary transformer 131 in a predetermined relationship, the rotor portion 139 of the resolver body 132 is disposed on the rotor portion support member 140 , the rotor portion 134 of the rotary transformer 131 is disposed on the rotation shaft 133 , and the rotor portion support member 140 and the rotation shaft 133 are coupled together. As the minimum configuration for forming a resolver, a configuration where the case 136 in which the stator portions 135 , 143 are disposed, and the rotor portion support member 140 in which the rotor portions 134 , 139 are disposed, and the rotation shaft 133 are coupled together is required. Even when multiplexing is considered on the basis of the minimum configuration, such multiplexing is hardly realized because means for coupling the rotation shaft is problematic. SUMMARY OF THE INVENTION It is an object of the invention to provide a resolver unit having a structure in which, in view of the above-discussed problems, the axial length is shortened to prevent the magnetic coupling characteristic between the rotary and stationary sides from being impaired, a winding generates more magnetic fluxes, and multiplexing is easily conducted, and also a resolver using such a resolver unit. In order to attain the object, the invention employs the following configuration. (1) A resolver unit comprising: an inner frame in which a cylinder portion is continuously disposed on a periphery of a disk portion; an outer frame in which an outer cylinder portion is continuously disposed on an outer periphery of an annular plate portion, and an inner cylinder portion is continuously disposed on an inner periphery of said annular plate portion; a rotary transformer comprising an outer portion and an inner portion, wherein said outer portion comprises an annular outer transformer coil and an annular outer transformer yoke, and said inner portion comprises an annular inner transformer coil and an annular inner transformer yoke; a resolver body comprising an inner portion and an outer portion, wherein said inner portion comprises a plurality of inner magnetic pole portions having an inner coil on an annular inner yoke, and said outer portion comprises a plurality of outer magnetic pole portions having an outer coil on an annular outer yoke, wherein said outer and inner portions of said rotary transformer are paired and opposingly placed, said outer and inner portions of said resolver body are paired and opposingly placed, one of said outer portion of said rotary transformer and said outer portion of said resolver body is disposed on a radially inner side face of said cylinder portion of said inner frame, one of said inner portion of said rotary transformer and said inner portion of said resolver body is disposed on a radially outer side face of said inner cylinder portion of said outer frame, said one being paired with and opposed to said outer portion which is disposed on said radially inner side face of said cylinder portion of said inner frame, the other one of said inner portion of said rotary transformer and said inner portion of said resolver body is disposed on a radially outer side face of said cylinder portion of said inner frame, said other one being not paired with said outer portion which is disposed on said radially inner side face of said cylinder portion of said inner frame, and one of said outer portion of said rotary transformer and said outer portion of said resolver body is disposed on a radially inner side face of said outer cylinder portion of said outer frame, said one being paired with and opposed to said inner portion which is disposed on said radially outer side face of said cylinder portion of said inner frame. (2). The resolver unit according to (1), wherein said outer and inner portions of said resolver body, and said outer and inner portions of said rotary transformer are continuously placed in a space between a face of said disk portion and a face of said annular plate portion. (3). A resolver which uses a resolver unit according to (1) or (2), wherein a shaft is disposed in said disk portion, said outer cylinder portion is disposed in a housing, and said shaft is rotatably disposed in said housing. (4). The resolver according to (3), wherein said housing comprises: an upper plate portion having an annular projection and an upper flange; an upper housing which upstands on said upper plate portion, and which comprises a side wall portion having a lower flange in an open end; a cylinder portion to which one of said inner and outer frames of said resolver unit is fixed; and a lower housing having a substrate flange opposed to said lower flange, wherein a shaft is disposed on said upper plate portion, and fixes the other one of said inner and outer frames of said resolver unit. (5). A resolver in which multiple resolver units according to (1) or (2) are combined to integrally operate, wherein adjacent ones of resolver units are coupled together at one of said annular plate portions and said disk portions, next adjacent ones of resolver units are coupled together at the other one of said annular plate portions and said disk portions, and then a required number of resolver units are similarly coupled together. (6). A resolver in which multiple resolver units according to (1) or (2) are combined to integrally operate, wherein in accordance with a degree of multiplexing, a required number of unit configurations each of which includes said outer frame, and in each of which placement relationships among said outer and inner portions of said resolver body, and said outer and inner portions of said rotary transformer that are continuously placed in a space between a face of said disk portion and a face of said annular plate portion are fixed are continuously disposed in a radial direction, a radius of said disk portion of said inner frame is elongated in accordance with a radial outward order of said unit configuration, and a width of said cylinder portion of said inner frame is increased by a degree of a plate thickness in accordance with the radial outward order of said unit configuration. (7). A resolver wherein multiple resolvers according to (6) are disposed in the axial direction. (8). A resolver according to (4), wherein an arbitrary number of said upper housings in each of which said resolver unit is housed in an internal space are coupled together, and an open end of a last one of said upper housings is sealed by said lower housing. The resolver unit of one embodiment of the invention can be configured by disposing the inner or outer portion of the resolver body and the outer or inner portion of the rotary transformer, on the inner frame to form a provisional assembly, disposing the remaining portions on the outer frame to form a provisional assembly, and mutually positioning the two provisional assemblies. Therefore, the resolver unit can be directly attached to a target apparatus, whereby the resolver unit can be used. In the resolver unit of the invention, it is preferable that the cylinder portion of the inner frame in which the inner portion of the resolver body is disposed on the outer side face and the outer portion of the rotary transformer is opposed to the inner side face is placed between the outer portion of the resolver body disposed on the outer cylinder portion of the outer frame and the inner portion of the rotary transformer disposed on the inner cylinder portion of the same outer frame. Therefore, gaps are restricted to two gaps or the gap between the outer and inner magnetic poles of the resolver body, and that between the outer and inner portions of the rotary transformer. The number of gaps can be made smaller than that in the example disclosed by JPA'639. In the resolver unit of the invention, it is preferable that the cylinder portion of the inner frame in which the inner portion of the rotary transformer is disposed on the outer side face and the outer portion of the resolver body is opposed to the inner side face is placed between the outer portion of the rotary transformer disposed on the outer cylinder portion of the outer frame and the inner portion of the resolver body disposed on the inner cylinder portion of the same outer frame. Therefore, gaps are restricted to two gaps or the gap between the outer and inner magnetic poles of the resolver body, and that between the outer and inner portions of the rotary transformer. The number of gaps can be made smaller than that in the example disclosed by JPA'639, and the gap adjustment can be easily conducted. In the resolver of the invention, it is preferable that when the inner frame is fixed, the outer frame is movable, and the outer portion of the rotary transformer and the inner portion of the resolver body are opposingly disposed on the front and rear faces of the cylinder portion of the inner frame, a winding of the transformer coil disposed in the outer portion of the rotary transformer can be connected by a short crossover wire to a winding of the inner coil disposed in the inner portion of the resolver body via the inner frame and the outer transformer yoke. Accordingly, a damage of the crossover wire due to vibrations, a wind pressure, or the like can be suppressed to a small degree. In the resolver of the invention, it is preferable that the inner frame is fixed, the outer frame is movable, and the inner portion of the rotary transformer and the outer portion of the resolver body are opposingly disposed on the front and rear faces of the cylinder portion of the inner frame. Therefore, a winding of the transformer coil disposed in the inner portion of the rotary transformer can be connected by a short crossover wire to a winding of the outer coil disposed in the outer portion of the resolver body via the inner frame and the inner transformer yoke. Accordingly, a damage of the crossover wire due to vibrations, a wind pressure, or the like can be suppressed to a small degree. In the resolver using a resolver unit of the invention, it is preferable that the disk portions of the inner frames or the annular plate portions of the outer frames are coupled together, whereby multiplexing in the axial or radial direction is easily conducted. In the resolver of the invention, it is preferable that all the configurations of the resolver body and the rotary transformer are accommodated between a face formed by the disk portion of the inner frame and that formed by the annular plate portion of the outer frame. Therefore, multiplexing can be conducted by using the disk portion or the annular plate portion. The invention is preferably configured by: the upper housing having the upper and lower flanges; the cylinder portion to which one of the inner and outer frames of the resolver unit is fixed; and the lower housing having the substrate flange opposed to the lower flange. The shaft fixing another one of the inner and outer frames of the resolver unit is disposed on the upper plate portion, the other one being not fixed to the cylinder portion, an arbitrary number of the upper housings in each of which the resolver unit is housed in an internal space are coupled together, and the open end of the last one of the upper housings is sealed by the lower housing. Therefore, even a single resolver or a multiplexed resolver can be easily configured. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B are views showing the configuration of a resolver unit of an embodiment of the invention, and FIG. 1C is a view showing modified embodiment of FIG. 1B . FIG. 2 is a sectional view of a multiplexed resolver using the resolver unit 1 of FIGS. 1A and 1B . FIGS. 3A to 3C are sectional views of another multiplexed resolver of the invention. FIGS. 4A to 4C are sectional views showing only a section of Embodiment 5 of the invention taken along the center of a shaft, and shows Housing example 2 . FIGS. 5A to 5C are sectional views showing only a section of Embodiment 6 of the invention taken along the center of the shaft, and shows Housing example 3 . FIG. 6 is a fragmentary sectional view of a related art resolver having a cylindrical stator assembly, and a rotor assembly which is placed coaxially with the cylindrical stator assembly. FIG. 7 is a sectional view of a related art flat type resolver which is shown in JPA'211. FIG. 8 is a view showing the configuration of an example disclosed in JPA'639. DETAILED DESCRIPTION OF THE INVENTION Embodiments of the invention will be described in detail with reference to the figures. A resolver of the invention includes a single resolver in which one resolver unit is incorporated, and a multiplexed resolver in which plural resolver units are integrally combined with one another. Embodiment 1 FIGS. 1A and 1C are views showing the configuration of a resolver unit of the invention. FIG. 1A is a front view as seen from a line IA—IA of FIG. 1B in which a predetermined center angle range is a correct front view, and the remaining center angle range is a schematic view showing a structure where the resolver unit is mainly formed into a circular. FIG. 1B is a sectional view showing a section taken along a line IB—IB of FIG. 1A , but in which its background is omitted to clarify the configuration. Hereinafter, a sectional view is similarly shown. The resolver unit 1 of FIGS. 1A and 1B is configured by an inner structure body 2 which is relatively on the centripetal side, and an outer structure body 3 which is on the centrifugal side, and serves as a unit basic structure in multiplexing. An arbitrary one of the inner structure body 2 and the outer structure body 3 may be set to a stationary side. When the stationary side is once determined, the other structure body may be set to a movable side in accordance with the determination. The resolver unit 1 of the invention can be configured by combining and positioning the two members of the inner structure body 2 and the outer structure body 3 . The inner structure body 2 and the outer structure body 3 can be configured as a resolver by the minimum structure by, for example, directly disposing an inner frame 6 and an outer frame 7 respectively on opposing apparatuses, i.e., a rotation member (not shown) such as a shaft of a motor, a power transmission shaft, or a shaft of an operation handle, and a support member (not shown) which is opposed to the rotation member, such as a housing of the motor, a case of the power transmission shaft, or a case for guiding the shaft of the operation handle. The inner structure body 2 is configured by the inner frame 6 , an outer portion 9 of a rotary transformer 8 , and an inner portion 11 of a resolver body 10 . The resolver body 10 includes a coil from which an electric signal corresponding to a rotation angle is taken out, a core, etc. The inner frame 6 is configured by a disk-like disk portion 12 , and a cylindrical cylinder portion 13 which is continuously disposed on the periphery of the disk portion 12 . The outer portion 9 of the rotary transformer 8 is configured by: an outer transformer yoke 14 that has a substantially U-like sectional shape in which an opening is centrally directed, and that is annular in a front view; and an outer transformer coil 15 that is placed in an annular recess of the outer transformer yoke 14 and having a substantially U-like sectional shape. The inner portion 11 of the resolver body 10 is configured by an inner core 16 and an inner coil 17 . The inner core 16 is configured by an annular inner yoke portion 18 , and plural inner magnetic pole portions 19 which are projected from the outer periphery of the inner yoke portion 18 . The inner core 16 is made by a magnetic material such as stacked steel plates. The outer structure body 3 is configured by the outer frame 7 , an inner portion 20 of the rotary transformer 8 , and an outer portion 21 of the resolver body 10 . The outer frame 7 is configured by: an annular plate portion 22 formed by an annular plate; a cylindrical inner cylinder portion 23 in which one end face is continuously disposed on the inner periphery of the annular plate portion 22 ; and a cylindrical outer cylinder portion 24 in which one end face is similarly continuously disposed on the outer periphery of the annular plate portion 22 . The inner portion 20 of the rotary transformer 8 is configured by: an inner transformer yoke 25 that has a substantially U-like sectional shape in which an opening is directed in the radially outward direction, and that is annular in a front view; and an inner transformer coil 26 that is placed in an annular recess of the inner transformer yoke 25 and having a substantially U-like sectional shape. The outer portion 21 of the resolver body 10 is configured by an outer core 27 and an outer coil 28 . The outer core 27 is configured by an annular outer yoke portion 29 , and plural outer magnetic pole portions 30 which are projected from the inner periphery of the outer yoke portion 29 . The outer core 27 is made by a magnetic material such as stacked steel plates. A crossover wire 31 which connects the outer transformer coil 15 to the inner coil 17 is placed via, for example, the outer transformer yoke 14 and an end face of the cylinder portion 13 of the inner frame 6 . When the crossover wire 31 is formed in this way, the length of the crossover wire 31 can be shortened, and a damage due to vibrations or a wind pressure can be suppressed to a small degree. When a recessed wiring groove (not shown) is disposed and embedded, damage can be further reduced. The outer and inner portions 21 and 11 of the resolver body 10 , and the outer and inner portions 9 and 20 of the rotary transformer 8 are continuously placed in a space between a face of the disk portion 12 and that of the annular plate portion 22 . (Case Where Inner Frame is Fixed: Inner Stator Type) In the case where the inner frame 6 is fixed to a stationary member (not shown), a shaft (not shown) or a rotating counter member is fixed to the inner cylinder portion 23 of the outer frame 7 , and the shaft or the like is rotatably fixed to the inner frame 6 or a support member (not shown). At this time, as shown in FIG. 1B , the rotary transformer 8 and the resolver body 10 are continuously placed in the space between the face of the disk portion 12 and that of the annular plate portion 22 . In this example, the outer portion 9 of the rotary transformer 8 functions as a primary side of a transformer, and the inner portion 20 of the rotary transformer 8 functions as a secondary side of the transformer. The outer portion 21 of the resolver body 10 functions as an excitation side, and the inner portion 11 of the resolver body 10 functions as a detection (output) side. A crossover wire (not shown) elongating from the inner transformer coil 26 of the inner portion 20 of the rotary transformer 8 functioning as the secondary side of the transformer, to the outer coil 28 of the outer portion 21 of the resolver body 10 functioning as the excitation side is extended along a side face of the annular plate portion 22 of the outer frame 7 . As required, a through hole is formed in the annular plate portion 22 , and the crossover wire is placed on a different side face. When a recessed wiring groove is formed on the side face of the annular plate portion 22 and the crossover wire is embedded and fixed by a resin, a wiring structure resistant to a wind pressure and vibrations can be obtained. (Case Where Outer Frame is Fixed: Outer Stator Type) In the case where the outer frame 7 is fixed to a support member (not shown), a shaft (not shown) or a rotating counter member is fixed to the disk portion 12 of the inner frame 6 , and the shaft or the like is rotatably fixed to the support member (not shown). At this time, as shown in FIG. 1B , the rotary transformer 8 and the resolver body 10 are continuously placed in the space between the face of the disk portion 12 and that of the annular plate portion 22 . In this example, the inner portion 20 of the rotary transformer 8 functions as a primary side of a transformer, and the outer portion 9 of the rotary transformer 8 functions as a secondary side of the transformer. The inner portion 11 of the resolver body 10 functions as an excitation side, and the outer portion 21 of the resolver body 10 functions as a detection (output) side. The crossover wire 31 elongating from the outer transformer coil 15 of the outer portion 9 of the rotary transformer 8 functioning as the secondary side of the transformer, to the inner coil 17 of the inner portion 11 of the resolver body 10 functioning as the excitation side is extended along, for example, the outer transformer yoke 14 and a side face of the cylinder portion 13 of the inner frame 6 . The outer portion 9 functioning as the secondary side of the rotary transformer 8 is disposed on one side face so as to sandwich the cylinder portion 13 of the inner frame 6 . The inner portion 11 functioning as the excitation side of the resolver body 10 is disposed on the other side face. The crossover wire elongating from the secondary side of the rotary transformer 8 to the excitation side of the resolver body 10 is placed via, for example, the outer transformer yoke 14 and the end face of the cylinder portion 13 of the inner frame 6 . Therefore, the crossover wire can be placed by a short distance, and influences on the crossover wire due to a wind pressure and vibrations can be suppressed. (Modification) The resolver unit 1 shown in FIGS. 1A and 1B has the configuration in which, with respect to the cylinder portion 13 of the inner frame 6 , the inner and outer portions 20 and 9 of the rotary transformer 8 are disposed on the radially inner side, and the inner and outer portions 11 and 21 of the resolver body 10 are disposed on the radially outer side. FIG. 1C is a sectional view showing an example in which the arrangement of FIG. 1B is modified. FIG. 1C is a sectional view showing only a section in the same manner as FIG. 1B . Unlike the configuration of FIG. 1B , with respect to the cylinder portion 13 of the inner frame 6 , the inner and outer portions 11 and 21 of the resolver body 10 may be disposed on the radially inner side, and the inner and outer portions 20 and 9 of the rotary transformer 8 may be disposed on the radially outer side. [Embodiment 2] (Multiplexing 1 ) (Housing Example 1 ) The multiplexed resolver of the invention is multiplexed by coupling together an arbitrary number of single-unit resolver units shown in FIGS. 1A and 1C in the direction of the shaft or the housing which will be described below. FIG. 2 is a sectional view of a multiplexed resolver using the resolver unit 1 of FIGS. 1A and 1B . A housing 33 is configured by an upper housing 34 and a lower housing 35 . The upper housing 34 is configured by an upper plate portion 36 which is substantially planar, and a cylindrical sidewall portion 37 . The upper plate portion 36 has a recess 41 which houses a bearing 40 , in the periphery of a center hole, a cylindrical thread portion 42 is projected from the vicinity of the outer periphery, and an upper flange 38 for attachment and coupling is provided in the periphery of the outer side. The sidewall portion 37 has a length corresponding to one stage of the resolver unit 1 , and a cylindrical thread portion 45 is disposed in the both axial ends. An arbitrary number of sidewall portions 37 can be coupled by the thread portions 45 . When one sidewall portion 37 is formed, a resolver is constituted. By contrast, the lower housing 35 has: a substrate portion 44 which is planar in the same manner as the upper plate portion 36 ; a recess 46 which houses the bearing 40 , in the periphery of a center hole of the substrate portion 44 ; and a substrate flange 47 for attachment and coupling, in the periphery of the outer side of the substrate portion 44 . In a shaft 32 , a required number of approximately columnar bodies 48 each having a length corresponding to the axial length of the resolver unit 1 are screwingly coupled by thread portions 49 . A lower flange 39 of the upper housing 34 , and the substrate flange 47 of the lower housing 35 are secured to each other by screwing or welding under the state where they are mutually positioned. The axial length of the sidewall portion 37 is an arbitrary integer multiple of the length of the single-unit resolver unit 1 . A side face of the disk portion 12 is positioned on one side face of the upper plate portion 36 , and that of the substrate portion 44 . An arbitrary number of resolver units 1 to which the shaft 32 is fixed are attached and positioned in a space of the side wall portion 37 , and at the same time the shaft 32 which couple the arbitrary number of resolver units 1 is rotatably passed through and supported by the bearings 40 , 40 housed in the upper plate portion 36 and the substrate portion 44 . When the resolver units 1 are attached into the upper housing 34 , adjacent resolver units 1 , 1 are coupled together by one combination of the annular plate portions 22 , 22 or the disk portions 12 , 12 , and the next adjacent resolver units 1 , 1 are coupled together by a combination different from the combination of the above coupling. Then, a required number of resolver units are similarly coupled together while the combinations are sequentially alternately changed. Specifically, a step of combining the disk portions 12 of the inner frames 6 in a back to back relationship, and that of combining the annular plate portions 22 of the outer frames 7 in a back to back relationship are sequentially combined to conduct multiplexing. In this case, the shaft 32 is secured to the disk portions 12 of the inner frames 6 , and the outer cylinder portions 24 of the outer frames 7 are fixed to the cylindrical sidewall portion 37 . One of the shaft 32 and the housing 33 is fixed, and the other is rotated. The housing 33 may be fixed to the above-mentioned arbitrary support member (not shown) other than the resolver. [Embodiment 3] (Multiplexing 2 ) FIGS. 3A to 3C are sectional views of another multiplexed resolver of the invention. FIG. 3A is a sectional view of a duplexed resolver of the invention which is duplexed in a radial direction. The other multiplexed resolver of the invention is multiplexed by radially coupling the single-unit resolver unit 1 shown in FIGS. 1A and 1B and a modified resolver unit F in which the configuration of the resolver unit 1 is partly modified, at an arbitrary number. The duplexed resolver of FIG. 3A is configured by the resolver unit 1 shown in FIG. 1B , and the modified resolver unit F. In the modified resolver unit F which can house the resolver unit 1 , the radius of a disk portion 12 b is made longer than the radius G of a disk portion 12 a of an inner frame 6 a of the resolver unit 1 by the length (increment) H of an annular plate portion 22 a to be (G+H), and the length J of the cylinder portion is (J+the thickness (increment) K of the disk portion). In accordance with the degree of mulitplexing, for example, n multiplexing where n is an arbitrary positive integer, then, the increments in the duplexing are increased by n times, thereby forming the whole shape. The radial length of the annular plate portion 22 a is constant. [Embodiment 4] (Multiplexing 3 ) FIG. 3B is a sectional view of a multidirectional multiplexed resolver of the invention in which a duplexed resolver 50 shown in FIG. 3A and duplexed in a radial direction is used as a unit, and the disk portions of the inner frames are coupled together in the direction of the shaft or the housing. FIG. 3C is a sectional view of a multidirectional multiplexed resolver of the invention in which the duplexed resolver 50 shown in FIG. 3A and duplexed in a radial direction is used as a unit, and the annular plate portions of the outer frames are coupled together in the direction of the shaft or the housing. In the coupling, a shaft 51 is secured to the disk portions 12 a, 12 b of the inner frames 6 a, 6 b, and an outer cylinder portion 24 b of an outer frame 7 b is fixed to a sidewall portion 52 of a cylindrical housing. One of the shaft 51 and the housing is set to a stationary side, and the other is set to a rotary side. The shaft 51 and the housing are rotatably fixed to an arbitrary support member (not shown). The duplexed resolvers are coupled by bonding together the disk portions 12 a, 12 b of the inner frames 6 a, 6 b as shown in FIG. 3B , or the annular plate portions 22 a, 22 b of the outer frame 7 a, 7 b as shown in FIG. 3C . When multiplexing is conducted in this way, multiplexing can be conducted in an arbitrary direction, and hence the occupation space in which the resolver is housed can be reduced. [Embodiment 5] (Housing Example 2 ) Housing example 2 is an example in which the inner frame 6 of the resolver unit 1 shown in FIG. 1B is set to the rotary side, and the outer frame 7 is set to the stationary side. FIGS. 4A to 4C are sectional views showing only a section of Embodiment 5 of the invention taken along the center of the shaft, and shows Housing example 2. FIG. 4A is an exploded sectional view of Housing example 2 , FIG. 4B is an assembly sectional view of Housing example 2, and FIG. 4C is a sectional view of the case where Housing example 2 is multiplexedly mounted. A housing 60 is configured by an upper housing 61 and a lower housing 62 . In the upper housing 61 , a planar upper plate portion 63 and a cylindrical sidewall portion 64 are integrally disposed. The upper plate portion 63 has an annular projection 76 in the periphery of a center hole, and a recess 66 which houses a bearing 65 , and comprises an upper flange 67 for attachment and coupling, in the periphery of the outer side. A free end of the sidewall portion 64 comprises a lower flange 68 for attachment and coupling which is opposed to the upper flange 67 . In a shaft 69 which is housed in the upper housing 61 , a columnar coupling shaft portion 70 and an engagement arm portion 71 are integrally continuously disposed. The coupling shaft portion 70 has an engagement projection 72 at the tip end. In the engagement arm portion 71 , a disk-like engagement disk plate portion 73 and a cylindrical engagement cylinder portion 74 are integrally continuously disposed. A recess 75 into which the engagement projection 72 at the tip end of the coupling shaft portion 70 is to be fitted is disposed at the center of the engagement disk plate portion 73 . The columnar coupling shaft portion 70 is rotatably pivoted by the bearing 65 which is housed in the upper plate portion 63 of the upper housing 61 . By contrast, the lower housing 62 has a substrate portion 77 which is planar, and a cylinder portion 78 which is perpendicularly disposed on the substrate portion 77 . A substrate flange 79 for attachment and coupling is disposed in the periphery of the outer side of the substrate portion 77 . A hole 80 through which the engagement projection 72 at the tip end of the shaft 69 is to be passed is formed in the disk portion 12 of the inner frame 6 of the resolver unit 1 . The lower flange 68 of the upper housing 61 , and the substrate flange 79 of the lower housing 62 are secured to each other by screwing or welding under the state where they are mutually positioned. The axial length of the sidewall portion 64 is basically equal to the length of the single-unit resolver unit 1 . Alternatively, the length of the sidewall portion 64 may be an arbitrary integer multiple of the length of the single-unit resolver unit 1 . The engagement cylinder portion 74 is configured so as to have an inner diameter which is equal to the outer diameter of the disk portion 12 of the inner frame 6 . Therefore, the engagement cylinder portion 74 is fitted onto the disk portion 12 of the inner frame 6 . The cylinder portion 78 of the lower housing 62 is fitted into the inner cylinder portion 23 of the outer frame 7 , thereby enabling the cylinder portion 78 and the inner cylinder portion 23 to be easily mutually positioned. The process of assembling the state of FIG. 4B from that of FIG. 4A is conducted in the following manner. (a 1 ) First, the cylinder portion 13 of the inner frame 6 is fitted and secured into the engagement arm portion 71 of the shaft 69 . (a 2 ) Next, while the cylinder portion 78 of the lower housing 62 is fitted into the inner cylinder portion 23 of the outer frame 7 , the annular plate portion 22 of the outer frame 7 is placed on the substrate portion 77 of the lower housing 62 . (a 3 ) Finally, the lower flange 68 of the upper housing 61 , and the substrate flange 79 of the lower housing 62 are positioned and secured to seal an open end of the upper housing 61 . The process of assembling the multiplexed state of FIG. 4C is conducted in the following manner. (b 1 ) First, the initial upper housing 61 is placed, and the cylinder portion 13 of the inner frame 6 is fitted and secured into the engagement arm portion 71 of the shaft 69 which is attached to the upper housing 61 . (b 2 ) Next, the outer cylinder portions 24 of the outer frames 7 is fitted, positioned, and fixed to the sidewall portion 64 of the upper housing 61 . (b 3 ) Then, the next upper housing 61 is attached to the initial upper housing 61 in the following manner: (b 3 - 1 ) the engagement projection 72 of the next shaft 69 is fitted, positioned, and secured to the recess 75 of the engagement arm portion 71 of the shaft 69 ; (b 3 - 2 ) the annular projection 76 of the upper plate portion 63 of the next upper housing 61 is butted against and positioned to the inner cylinder portion 23 of the outer frame 7 ; and (b 3 - 3 ) the lower flange 68 of the initial upper housing 61 is positioned and secured to the upper flange 67 of the next upper housing 61 . (b 4 ) The above steps are sequentially executed a required number of times in accordance with the degree of multiplexing. (b 5 ) Finally, the steps (a 2 ) and (a 3 ) above are implemented. Alternatively, the shaft may be fixed, and the housing is rotated contrary to the above-described example. (Effects of Embodiment 5) In Embodiment 5, the housing which, as shown in FIG. 4 , is configured by the shaft, the upper housing, and the lower housing is used, whereby the single-unit resolver unit 1 can be operably housed in the housing. An arbitrary number of resolver units 1 can be integrally incorporated in an interlockingly operable manner to constitute a multiplexed resolver, by combining arbitral numbers of shafts, upper housings, and lower housings. Namely, a single resolver and a multiplexed resolver can be adequately constituted by combining the shaft(s), the upper housing(s), and the lower housing(s) in predetermined relationships. [Embodiment 6] (Housing Example 3 ) Housing example 3 is an example in which, contrary to Housing example 2 , the inner frame 6 of the resolver unit 1 shown in FIG. 1B is set to the stationary side, and the outer frame 7 is set to the rotary side. FIGS. 5A to 5C are sectional views showing only a section of Embodiment 6 of the invention taken along the center of the shaft, and shows Housing example 3 . FIG. 5A is an exploded sectional view of Housing example 3 , FIG. 5B is an assembly sectional view of Housing example 3 , and FIG. 5C is a sectional view of the case where Housing example 3 is multiplexedly mounted. Housing example 3 of FIGS. 5A to 5C is different from Housing example 2 of FIGS. 4A to 4C in that an engagement arm portion 71 a of the shaft 69 is fitted and fixed to the inner cylinder portion 23 of the outer frame 7 , and that a cylinder portion 78 a of the lower housing 62 is fitted and fixed to the cylinder portion 13 of the inner frame 6 . The other components other than these points are identical with those of Housing example 2 . Therefore, they are denoted by the same reference numerals, and their description is omitted. Alternatively, the shaft may be fixed, and the housing is rotated contrary to the above-described example. (Effects of Embodiment 6) In Embodiment 6, the housing which, as shown in FIGS. 5A to 5C , is configured by the shaft, the upper housing, and the lower housing is used, whereby the single-unit resolver unit 1 can be operably housed in the housing. An arbitrary number of resolver units 1 can be integrally incorporated in an interlockingly operable manner to constitute a multiplexed resolver, by combining arbitral numbers of shafts, upper housings, and lower housings. Namely, a single resolver and a multiplexed resolver can be adequately constituted by combining the shaft(s), the upper housing(s), and the lower housing(s) in predetermined relationships.

A resolver unit having a structure in which the axial length is shortened to prevent the magnetic coupling characteristic between the rotary and stationary sides from being impaired, a winding generates more magnetic fluxes, and multiplexing is easily conducted, and also a resolver using such a resolver unit are provided.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is related to commonly owned copending Provisional Application Ser. No. 60/026,716, filed Sep. 26, 1996, and claims the benefit of its earlier filing date under 35 U.S.C. 119(e). FIELD OF THE INVENTION [0002] This invention relates to active derivatives of poly(ethylene glycol) and related hydrophilic polymers with a reactive moiety at one end of the polymer chain suitable for chemical coupling to another molecule. BACKGROUND OF THE INVENTION [0003] Chemical attachment of the hydrophilic polymer poly(ethylene glycol)(PEG), which is also known as poly(ethylene oxide) (PEO), to molecules and surfaces is of great utility in biotechnology. In its most common form PEG is a linear polymer terminated at each end with hydroxyl groups: HO—CH 2 CH 2 O— (CH 2 CH 2 O) n —CH 2 CH 2 —OH This polymer can be represented in brief form as HO-PEG-OH where it is understood that the -PEG- symbol represents the following structural unit: —CH 2 CH 2 O—(CH 2 CH 2 O) n —CH 2 CH 2 — In typical form n ranges from approximately 10 to approximately 2000. [0004] PEG is commonly used as methoxy-PEG-OH, or mPEG, in which one terminus is the relatively inert methoxy group, while the other terminus is a hydroxyl group that is subject to ready chemical modification. CH 3 O—(CH 2 CH 2 O) n —CH 2 CH 2 —OHmPEG [0005] PEG is also commonly used in branched forms that can be prepared by addition of ethylene oxide to various polyols, such as glycerol, pentaerythritol and sorbitol. For example, the four-arm, branched PEG prepared from pentaerythritol is shown below: C(CH 2 —OH) 4 +nC 2 H 4 O→C[CH 2 O—(CH 2 CH 2 O) n —CH 2 CH 2 —OH] 4 [0006] The branched polyethylene glycols can be represented in general form as R(-PEG—OH) n in which R represents the central “core” molecule, such as glycerol or pentaerythritol, and n represents the number of arms. [0007] PEG is a well known polymer having the properties of solubility in water and in many organic solvents, lack of toxicity, and lack of immunogenicity. One use of PEG is to covalently attach the polymer to insoluble molecules to make the resulting PEG-molecule “conjugate” soluble. For example, Greenwald, Pendri and Bolikal in J. Org. Chem., 60, 331-336 (1995) have shown that the water-insoluble drug taxol, when coupled to PEG, becomes water soluble. [0008] In related work, Davis et al. in U.S. Pat. No. 4,179,337 have shown that proteins coupled to PEG have enhanced blood circulation lifetime because of reduced rate of kidney clearance and reduced immunogenicity. Hydrophobic proteins have been described that gain increased water solubility upon coupling to PEG. These applications and many leading references are described in the book by Harris (J. M. Harris, Ed., “Biomedical and Biotechnical Applications of Polyethylene Glycol Chemistry,” Plenum, N.Y., 1992). [0009] To couple PEG to a molecule such as a protein or on a surface, it is necessary to use an “activated derivative” of the PEG having a functional group at the terminus suitable for reacting with some group on the surface or on the protein (such as an amino group). Among the many useful activated derivatives of PEG is the succinimidyl “active ester” of carboxymethylated PEG as disclosed by K. Iwasaki and Y. Iwashita in U.S. Pat. No. 4,670,417. This chemistry can be illustrated with the active ester reacting with amino groups of a protein (the succinimidyl group is represented as NHS and the protein is represented as PRO—NH 2 ): PEG-O—CH 2 —CO 2 —NHS+PRO—NH 2 →PEG-O—CH 2 —CO 2 —NH—PRO [0010] Problems have arisen in the art. Some of the functional groups that have been used to activate PEG can result in toxic or otherwise undesirable residues when used for in vivo drug delivery. Some of the linkages that have been devised to attach functional groups to PEG can result in an undesirable immune response. Some of the functional groups do not have appropriate selectivity for reacting with particular groups on proteins and can tend to deactivate the proteins. [0011] Attachment of a PEG derivative to a substance can have a somewhat unpredictable impact on the substance. Proteins, small drugs, and the like can have less biological activity when cojugated with a PEG derivative. For others, activity is increased. [0012] Another example of a problem that has arisen in the art is exemplified by the succinimidyl succinate “active ester” mPEG-SS (the succinimidyl group is represented as NHS): [0013] The mPEG-SS active ester is a useful compound because it reacts rapidly with amino groups on proteins and other molecules to form an amide linkage (—CO—NH—). A problem with the mPEG-SS active ester, which was recognized by K. Iwasaki and Y. Iwashita in U.S. Pat. No. 4,670,417, is that this compound possesses an ester linkage in the backbone that remains after coupling to an amine such as a protein (represented as PRO—NH 2 ): mPEG-SS+PRO—NH 2 →mPEG-O 2 C—CH 2 CH 2 —CONH—PRO [0014] The remaining ester linkage is subject to rapid hydrolysis and detachment of PEG from the modified protein. Too rapid hydrolysis can preclude use of a PEG derivative for many applications. Several approaches have been adopted to solve the problem of hydrolytic instability. For example, mPEG succinimidyl carbonate has been proposed, which contains only ether linkages in the polymer backbone and reacts with proteins to form a conjugate that is not subject to hydrolysis. [0015] It would be desirable to provide alternative PEG derivatives that are suitable for drug delivery systems, including delivery of proteins, enzymes, and small molecules, or for other biotechnical uses. It would also be desirable to provide alternative PEG derivatives that could enhance drug delivery systems or biotechnical products. SUMMARY OF THE INVENTION [0016] The invention provides chemically active polyethylene glycols and related polymers that are suitable for coupling to other molecules to give water-soluble conjugates, and in which the linkage between the polymer and the bound molecule is subject to predetermined cleavage for controlled delivery of the bound molecule into the surrounding environment. [0017] The PEG and related polymer derivatives of the invention contain weak, hydrolytically unstable linkages near the reactive end of the polymer that provide for a sufficient circulation period for a drug-PEG conjugate and then hydrolytic breakdown of the conjugate and release of the bound molecule. Methods of preparing the active PEGs and elated polymers, PEG conjugates, and methods of preparing the PEG conjugates are also included in the invention. [0018] The PEG and related polymer derivatives of the invention are capable of imparting water solubility, size, slow rate of kidney clearance, and reduced immunogenicity to the conjugate, while also providing for controllable hydrolytic release of the bound molecule into the aqueous environment by design of the linkage. The invention can be used to enhance solubility and blood circulation lifetime of drugs in the blood stream and then to deliver a drug into the blood stream substantially free of PEG. In some cases, drugs that previously had reduced activity when permanently conjugated to PEG can have therapeutically suitable activity when coupled to a degradable PEG in accordance with the invention. [0019] In general form, the derivatives of the invention can be described by the following equations: In the above equations, [0020] “Poly” is a linear or branched polyethylene glycol of molecular weight from 300 to 100,000 daltons. Poly can also be a related nonpeptidic polymer as described in the Detailed Description; n is the number of chemically active end groups on Poly and is the number of molecules that can be bound to Poly; W is a hydrolytically unstable weak group; T is a reactive group; (Y—P′) n represents a molecule for conjugation to Poly, in which Y is a reactive group that is reactive with T and P′ is the portion of the molecule that is to be bound and released, including, for example, a peptide P′ in which Y is an amine moiety and T is a PEG activating moiety reactive with amine moieties; X is the new linkage formed by reaction of Y and T; and G and I are new groups formed by hydrolysis of W. [0027] Examples of hydrolytically unstable groups W include carboxylate esters, phosphate esters, acetals, imines, orthoesters, peptides and oligonucleotides. T and Y are groups reactive toward each other. There are many examples of such groups known in organic chemistry. Some examples include active esters reacting toward amines, isocyanates reacting toward alcohols and amines, aldehydes reacting toward amines, epoxide reacting toward amines, and sulfonate esters reacting toward amines. Examples of P′ include peptide, oligonucleotide and other pharmaceuticals. Examples of X include amide from reaction of active esters with amine, urethane from reaction of isocyanate with hydroxyl, and urea from reaction of amine with isocyanate. Examples of G and I are alcohol and acid from hydrolysis of carboxylate esters, aldehyde and alcohol from hydrolysis of acetals, aldehydes and amine from hydrolysis of imines, phosphate and alcohol from hydrolysis of phosphate esters, amine and acid from hydrolysis of peptide, and phosphate and alcohol from hydrolysis of oligonucleotides. [0028] An example of the invention is shown in the following equation for conjugation of methoxy-PEG-OH (mPEG) with a peptide drug and for hydrolytic release of the peptide drug. The weak linkage W in the conjugate is an ester group. [0029] The released peptide contains no mPEG. The released peptide contains an additional short molecular fragment, which is sometimes called a “tag” and is the portion of the linkage opposite the PEG from the hydrolytically unstable linkage. [0030] Thus, the invention provides hydrolytically unstable linkages in activated PEGs and related polymers that are suitable for controlled delivery of drugs from conjugation with the PEG to the surrounding environment. Several types of linkages, including ester linkages, are suitable for use in the invention. However, the ester linkages of the invention, in contrast to mPEG-SS and mPEG-SG, provide for variation and control of the rate of hydrolytic degradation. [0031] The foregoing and other objects, advantages, and features of the invention, and the manner in which the same are accomplished, will be more readily apparent upon consideration of the following detailed description of the invention taken in conjuntion with the accompanying drawings, which illustrates an exemplary embodiment. BRIEF DESCRIPTION OF THE DRAWINGS [0032] FIGS. 1 through 3 are illustrations of MALDI-MS spectra of the molecular weight distribution of an mPEG-HBA and subtilisin conjugate at different times after preparation. FIG. 1 is 1 day. FIG. 2 is 8 days. FIG. 3 is 14 days. DETAILED DESCRIPTION [0033] The following detailed description describes various examples of the derivatives of the invention as described by the following general equations presented in the summary: [0034] In the discussion below, Poly will often be referred to for convenience as PEG or as poly(ethylene glycol). However, it should be understood that other related polymers are also suitable for use in the practice of the invention and that the use of the term PEG or poly(ethylene glycol) is intended to be inclusive and not exclusive in this respect. [0035] Poly(ethylene glycol) is useful in the practice of the invention. PEG is used in biological applications because it has properties that are highly desirable and is generally approved for biological or biotechnical applications. PEG typically is clear, colorless, odorless, soluble in water, stable to heat, inert to many chemical agents, does not hydrolyze or deteriorate, and is nontoxic. Poly(ethylene glycol) is considered to be biocompatible, which is to say that PEG is capable of coexistence with living tissues or organisms without causing harm. More specifically, PEG is not immunogenic, which is to say that PEG does not tend to produce an immune response in the body. When attached to a moiety having some desirable function in the body, the PEG tends to mask the moiety and can reduce or eliminate any immune response so that an organism can tolerate the presence of the moiety. Accordingly, the activated PEGS of the invention should be substantially non-toxic and should not tend substantially to produce an immune response or cause clotting or other undesirable effects. [0036] Other water soluble polymers than PEG are suitable for similar modification. These other polymers include poly(vinyl alcohol) (“PVA”); other poly(alkylene oxides) such as poly(propylene glycol) (“PPG”) and the like; and poly(oxyethylated polyols) such as poly(oxyethylated glycerol), poly(oxyethylated sorbitol), and poly(oxyethylated glucose), and the like. The polymers can be homopolymers or random or block copolymers and terpolymers based on the monomers of the above polymers, straight chain or branched, or substituted or unsubstituted similar to mPEG and other capped, monofunctional PEGs having a single active site available for attachment to a linker. [0037] Specific examples of suitable additional polymers include poly(oxazoline), poly(acryloylmorpholine) (“PAcM”), and poly(vinylpyrrolidone) (“PVP”). PVP and poly(oxazoline) are well known polymers in the art and their preparation and use in the syntheses described for mPEG should be readily apparent to the skilled artisan. PAcM and its synthesis and use are described in U.S. Pat. Nos. 5,629,384 and 5,631,322, the contents of which are incorporated herein by reference in their entirety. [0038] It should be understood that by “drug” is meant any substance intended for the diagnosis, cure, mitigation, treatment, or prevention of disease in humans and other animals, or to otherwise enhance physical or mental well being. The invention could be used for delivery of biologically active substances generally that have some activity or function in a living organism or in a substance taken from a living organism. [0039] The terms “group,” “functional group,” “moiety,” “active moiety,” “reactive site,” and “radical” are all somewhat synonymous in the chemical arts and are used in the art and herein to refer to distinct, definable portions or units of a molecule and to units that perform some function or activity and are reactive with other molecules or portions of molecules. [0040] The term “linkage” is used to refer to groups that normally are formed as the result of a chemical reaction and typically are covalent linkages. Hydrolytically stable linkages means that the linkages are stable in water and do not react with water at useful pHs for an extended period of time, potentially indefinitely. Hydrolytically unstable linkages are those that react with water, typically causing a molecule to separate into two or more components. The linkage is said to be subject to hydrolysis and to be hydrolyzable. The time it takes for the linkage to react with water is referred to as the rate of hydrolysis and is usually measured in terms of its half life. [0041] The invention includes poly(ethylene glycols) containing ester groups as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules to be delivered in vivo or into a substance taken from a living entity: PEG-W—CO 2 —NHS [0042] The invention includes poly(ethylene glycols) containing ester groups as weak linkages and isocyanates as reactive groups useful for coupling to amine- and alcohol-containing molecules: PEG-W—N═C═O Where W=—O— (CH 2 ) n —CO 2 — (CH 2 ) m —n=1 to 5, m=2 to 5 [0043] The invention includes poly(ethylene glycols) containing acetal groups as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules: PEG-W—CO 2 —NHS For example and where n=1-10, Z=—O—C 6 H 4 — and —O— (CH 2 ) m —CH 2 — m=1-5 R′=alkyl or H [0047] The invention inlcudes poly(ethylene glycols) containing imine groups as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules: PEG-W—CO 2 —NHS Where W=-Z-CH═N—(CH 2 ) m ° m=1-5 and where Z=—O—C 6 H 4 — and —O—(CH 2 ) m —CH 2 m=1-5 [0050] The invention also includes poly(ethylene glycols) containing phosphate ester groups as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules: PEG-W—CO 2 —NHS Where W=—(CH 2 ) n —OPO 3 —(CH 2 ) m —n and m=1-5 [0051] The invention includes poly(ethylene glycols) containing ester-linked amino acids as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules. An advantage of this derivative is that hydrolytic breakdown leaves a biologically acceptable amino acid attached to the released molecule: PEG-W—CO 2 —NHS Where W=—O—(CH 2 ) n —CO 2 —(CH 2 ) m —CH(NH-t-Boc)- n=1-5, m=1-5 t-Boc=(CH 3 ) 3 C—O—CO— [0053] The invention includes poly(ethylene glycols) containing peptides as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules. An advantage of this derivative is that hydrolytic breakdown leaves a usually biologically acceptable peptide fragment attached to the released molecule: PEG-W—CO 2 —NHS Where W=—CO(NH—CHR—CO) n —NH—CHR— n=2-20 R=the set of substituents typically found on α-amino acids [0055] The invention includes poly(ethylene glycols) containing oligonucleotides as weak linkages and succinimidyl esters as reactive groups useful for coupling to amine-containing molecules. An advantage of this derivative is that hydrolytic breakdown leaves the biologically acceptable oligonucleotide fragment attached to the released molecule: PEG-W—CO 2 —NHS Where W=oligonucleotide [0056] It should also be recognized that branched activated PEGs can be prepared in accordance with the invention having weak linkages near the reactive end of the polymer for controlled hydrolytic degradation. Suitable branched PEGs can be prepared in accordance with International Publication No. WO 96/21469, entitled Multi - Armed, Monofunctional, and Hydrolytically Stable Derivatives of Poly ( Ethylene Glycol ) and Related Polymers For Modification of Surfaces and Molecules , which was filed Jan. 11, 1996, the contents of which are incorporated herein in their entirety by reference. These branched PEGs can then be modified in accordance with the present teachings. [0057] The invention is illustrated with respect to several specific examples below, including determination of hydrolysis half lives for specific derivatives. EXAMPLES Example 1 Preparation of CH 3 O-PEG-O—(CH 2 ) n —COO—CH 2 —COOH (n=1: mPEG-CM-GA-NHS, and n=2: mPEG-PA-GA-NHS) [0058] Reactions: [0059] CH 3 O-PEG-O—(CH 2 ) n —COOH 3000 (3.0 g, 1 mmole, mPEG-CM or mPEG-PA) was azeotropically dried with 60 ml of toluene under N 2 . After two hours, the solution was cooled to room temperature, and thionyl chloride solution (2 ml, 4 mmole) in CH 2 CL 2 was injected. The solution was stirred at room temperature overnight. The solvent was condensed on a rotary evaporator and the residual syrup was dried in vacuo for about four hours over P 2 O 5 powder. Glycolic acid (0.2 g, 2.7 mmole) was azeotropically distilled with 70 ml of 1,4-dioxane and the distillation was stopped when approximately 20 ml of solution remained. The solution was slowly cooled to room temperature under N 2 . The glycolic acid/dioxane solution was then added to the dried PEG acyl chloride. After the PEG was dissolved, 0.6 ml of dry triethylamine was injected to the system (precipitate formed immediately) and the solution was stirred overnight. The salt was removed by filtration and the filtrate was condensed on a rotary evaporator at 55° C. and dried in vacuo. The crude product was then dissolved in 100 ml of distilled water and the pH of the solution was adjusted to 3.0. The aqueous phase was extracted three times with a total of 80 ml of methylene chloride. The combined organic phase was dried over sodium sulfate, filtered to remove salt, condensed on a rotary evaporator, and added to 100 ml of ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 2.55 g (85%). 1 H NMR(DMSO-d 6 ): δ 3.5 (br m, PEG), 4.3-4.6 (s, PEGCOOC H 2 COOH), 2.59 (t, PEGOCH 2 CH 2 COO (PA)), 4.19 (s, PEGOC H 2 COO (CM)). Example 2 Preparation of HOOC—CH 2 —OOCH 2 —O-PEG-O—CH 2 —COO—CH 2 —COOH [0060] Reactions [0061] Difunctional carboxymethyl PEG-ester benzyl glycolate 20,000: Difunctional carboxymethyl PEG 20,000 (4 gram, 0.4 mmole acid group), benzyl glycolate (0.6 mmole), dimethylaminopyridine (0.44 mmole), 1-hydroxybenzotriazole (0.4 mmole) and dicyclohexylcarbodiimide (0.56 mmole) were dissolved in 40 ml of methylene chloride. The solution was stirred at room temperature under N 2 overnight. The solvent was then removed under vacuum and the resulting residue was added to 20 ml of toluene at 40° C. The undissolved solid was removed by filtration and the filtrate was added to 200 ml of ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 4 gram (100%). 1 H NMR(DMSO-d 6 ): δ 3.5 (br m, PEG), 4.81 (s, PEGCOOC H 2 COOCH 2 C 6 H 5 ), 5.18 (s, PEGOCH 2 COOCH 2 COOC H 2 C 6 H 5 ), 7.37 (s, PEGOCH 2 COOCH 2 COOCH 2 C 6 H 5 ), 4.24 (s, PEGOCH 2 COOCH 2 COOCH 2 C 6 H 5 ). [0062] Difunctional carboxymethyl PEG-ester benzyl glycolate 20,000 (3 gram) and Pd/C (10%, 0.8 gram) were added to 30 ml of 1,4-dioxane. The mixture was shaken with H 2 (40 psi) at room temperature overnight. The Pd/C was removed by filtration and the solvent was condensed by rotary evaporation. The resulting syrup was added to 100 ml of ether. The precipitated product was collected by filtration and dried in vacuo. Yield 2.4 gram (80%). 1 H NMR(DMSO-d 6 ): δ 3.5 (br m, PEG), 4.56 (s, PEGCOOC H 2 COOH), 4.20 (s, PEGOC H 2 COOCH 2 COOH). Example 3 Preparation of CH 3 O-PEG-O— (CH 2 ) n —COO—CH 2 —COONHS [0063] Reactions: [0064] CH 3 O-PEG-O— (CH 2 ) n —COO—CH 2 —COOH (1 g, approx. 0.33 mmole) and 42 mg N-hydroxysuccinimide (NHS) (0.35 mmole) was dissolved in 30 ml of dry methylene chloride. To it was added dicyclohexylcarbodiimide (DCC) (80 mg, 0.38 mmole) in 5 ml of dry methylene chloride. The solution was stirred under nitrogen overnight and the solvent was removed by rotary evaporation. The resulting syrup was redissolved in 10 ml of dry toluene and the insoluble solid was filtered off. The solution was then precipitated into 100 ml of dry ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 0.95 g (95%). 1 H NMR (DMSO-d 6 ): δ 3.5 (br m, PEG), 5.15-5.21 (s, PEGCOOC H 2 COONHS), 2.67 (t, PEGOCH 2 C H 2 COO (PA)), 4.27 (s, PEGOC H 2 COO ppm(CM)), 2.82 (s, NHS, 4H). Example 4 Preparation of [0065] Reactions: [0066] CH 3 O-PEG-O—(CH 2 ) n —COO—CH 2 —COOH (1.5 g, approx. 0.5 mmole), 140 mg p-nitrophenol (1 mmole) and 65 mg dimethylaminopyridine (DMAP) (0.525 mmole) were dissolved in 30 ml of dry methylene chloride. To the resulting solution was added dicyclophexylcarbodiimide (DCC) (120 mg, 0.575 mmole) in 5 ml of dry methylene chloride. The solution was stirred under nitrogen overnight and the solvent was removed by rotary evaporation. The resulting syrup was redissolved in 10 ml of dry toluene and the insoluble solid was removed by filtration. Then the solution was precipitated into 100 ml of dry ethyl ether. The product was reprecipitated with ethyl ether, then collected by filtration and dried in vacuo. Yield 1.425 g (95%). 1 H NMR (DMSO-d 6 ): δ 3.5 (br m, PEG), 5.01 (s, PEGCOOC H 2 COONP), 2.69 (t, PEGOC H 2 CH 2 COO (PA)), 8.35 & 7.48 (d&d, H a & H b in NP, 4H). Example 5 Preparation of CH 3 O-PEG-O—(CH 2 ) n —COO—CH(CH 3 )CH 2 —COONHS (n=1: mPEG-CM-HBA-NHS and n=2: mPEG-PA-HBA-NHS [0067] Reactions: [0068] CH 3 O-PEG-O—(CH 2 ) n —COOH 3000 (3.0 g, 1 mmole) was azeotropically dried with 60 ml of toluene under N 2 . After two hours, the solution was slowly cooled to room temperature. To the resulting solution was added thionyl chloride solution (3 ml, 6 mmole) in CH 2 CL 2 , and the solution was stirred overnight. The solvent was condensed by rotary evaporation and the syrup was dried in vacuo for about four hours over P 2 O 5 powder. 3-hydroxybutyric acid (0.30 g, 2.7 mmole) was azeotropically dried with 70 ml of 1,4-dioxane on a rotary evaporator. The distillation was stopped when approximately 20 ml of solution remained. It was then slowly cooled to room temperature under N 2 , and the solution was added to the dried PEG acyl chloride. After the PEG was dissolved, 0.6 ml of dry triethylamine was injected to the system (precipitate formed immediately) and the solution was stirred overnight. The salt was removed by filtration and the filtrate was condensed on a rotary evaporator at 55° C. and dried in vacuo. The crude product was then dissolved in 100 ml of distilled water and the pH of the solution was adjusted to 3.0. The aqueous phase was extracted three times with a total of 80 ml of methylene chloride. The organic phase was dried over sodium sulfate, filtered to remove salt, condensed on a rotary evaporator, and added to 100 ml of ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 2.76 g (92%). 1 H NMR (DMSO-d 6 ): δ 3.5 (br m, PEG), 2.54 (d, PEGCOOCH(CH 3 )C H 2 COOH), 5.1 (h, PEGCOOC H (CH 3 )CH 2 COOH), 1.2 (d, PEG-COOCH(C H 3 )CH 2 COOH), 2.54 (t, PEGOCH 2 C H 2 COO (PA)), 4.055 (s, PEGOC H 2 COO (CM)). [0069] mPEG-ester butyric acid NHS ester (CM-HBA-NHS or PA-HBA-NHS): mPEG-ester butyric acid 3000 (1 g, approx., 0.33 mmole, CM-HBA-COOH or PA-HBA-COOH) and 42 mg N-hydroxysuccinimide (NHS) (0.35 mmole) was dissolved in 30 ml of dry methylene chloride. To this solution was added dicyclohexylcarbodiimide (DCC) 80 mg, 0.38 mmole) in 5 ml of dry methylene chloride. The solution was stirred under nitrogen overnight and the solvent removed by rotary evaporation. The residual syrup was redissolved in 10 ml of dry toluene and the insoluble solid was removed by filtration. The solution was then precipitated into 100 ml of dry ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield 0.94 g (94%). 1 H NMR(DMSO-d 6 ): δ 3.5 (br m PEG), 3.0-3.2 (m, COOCH(CH 3 )C H 2 COONHS), 5.26 (h, COOC H (CH 3 )CH 2 —COONHS), 1.3 (d, COOCH(C H 3 )CH 2 COONHS), 2.54 (t, OCH 2 C H 2 COO (PA)), 4.1 (s, OC H 2 COO (CM)), 2.81 (s, NHS). Example 6 [0000] Determination of Hydrolytic Half-Lives of the Ester Linkages [0070] Reactions: [0071] Preparation of CH 3 O-PEG-O— (CH 2 ) n —COO—CH 2 —CONH-PEG-OCH 3 : CH 3 O-PEG-O—(CH 2 ) n —COO—CH 2 —COOH 3000 (0.5 g), 1 equiv. of mPEG-NH 2 2000 and 1 equiv. of 1-hydroxybenzotriazole (HOBT) was dissolved in 50 ml of methylene chloride. To this solution was added one equivalent of dicyclohexylcarbodiimide (DCC) and the solution was stirred at room temperature overnight. The solvent was partially evaporated, the insoluble salt was filtered, and the filtrate was added into a large excess of ethyl ether. The precipitate was collected by filtration and dried in vacuo. Yield: 0.8 g (95%). 1 H MUR (DMSO-d 6 ): δ 3.5 (br m, PEG), 2.34 (t, —CONHC H 2 CH 2 O-PEG-). [0072] Determination of hydrolytic half-lives of PEG ester conjugates with PEG amine: The conjugates from the above step and 20 wt % PEG 20,000 (as internal standard) were dissolved in a buffer solution. Then the concentration of the conjugate (C) and its hydrolysis product were monitored by HPLC-GPC (Ultrahydrogel 250 column, 7.8×300 mm, Waters) at predetermined time. The hydrolytic half-lives were obtained from the slope of the natural logarithm of C at the time t minus C at infinite time versus time, assuming 1 st order kinetics. TABLE 1 Hydrolysis Half-Lives (days, unless noted otherwise) of the Ester Linkages Formed Between 1 and mPEG Amine (±10%) Double-Ester PEG Used CM-GA PA-GA CM-HBA PA-HBA pH 7.0 7.0 8.1 7.0 8.1 7.0 8.1 23° C. 3.2 43 6.5 — 15 — 120 37° C. 14 h 7.6 — 14 — 112 — 50° C.  4 h 2.2 —  5 —  58 — Example 7 [0000] Determination of Hydrolysis Half-Lives of the Active Ester [0073] Reactions: R═CH 2 or CH(CH 3 )CH 2 ; L=leaving group such as succinimidyl or p-nitrophenyl group. [0076] Determination of hydrolysis half-lives of PEG active ester: Measurements were conducted using a HP8452a UV-VIS spectrophotometer. In an experiment, 1 mg PEG active ester was dissolved in 3.0 ml of buffer solution and shaken promptly to obtain solution as soon as possible. Then the solution was transferred into an UV cuvette and the absorbance at 260 nm for NHS ester or at 402 nm for the p-nitrophenyl ester was followed as a function of time. The hydrolytic half life was determined from the first order kinetic plot (natural logarithm of final absorbance minus absorbance at the time t versus time). TABLE 2 Hydrolysis Half-Lives of Succinimidyl Active Esters (R = NHS) and p-nitrophenyl Active Esters (R = NP) of PEG-ester Acids at pH 8.1 and Room Temperature R CM-GA-R PA-GA-R CM-HBA-R PA-HBA-R NHS 11 s 11 s 12 min 12 min NP   7 min   7 min — — Example 8 [0000] Monitoring Hydrolytic Release of the Peg from its Protein Conjugate by MALDI-TOF Mass Spectrometry [0077] Modification of subtilisin with the PEG: To a subtilisin solution (1 ml, 2 mg/ml in 0.2M boric buffer pH 8.0) was added 15 mg mPEG-CM-HBA-NHS 3000. The solution was placed in an automatic shaker at room temperature. At predetermined time periods, 50 μl of the solution was removed and preserved in a refrigerator for MALDI-TOF MS measurement. [0078] MALDI spectra was measured on a PerSeptive Biosystems' Voyager linear time-of-flight instrument. Briefly, a nitrogen laser lamda=337 nm, 10 ns pulse width) was used to generate ions which were extracted with a potential of 30 kV. Ions drifted through a 1.3 m drift tube and were monitored in positive ion mode. [0079] Protein samples were dissolved in deionized H 2 O or 50 mM NaCl solution to a concentration of approximately 10 pmol/μl. The matrix, 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid), was dissolved in a 80:20 by volume ratio of acetonitrile to deionized water at a concentration of 10 mg/ml. 1 μl of the solution was deposited on the sample plate and then mixed with 1 μl of matrix solution. The sample was allowed to crystallize by solvent evaporation under ambient conditions. MALDI-MS spectra of the molecular weight distribution of the mPEG-HBA and subtilisin conjugate are shown in FIGS. 1 through 3 for different times after preparation. FIG. 1 is 1 day. FIG. 2 is 8 days. FIG. 3 is 14 days. Example 9 Preparation of [0080] Reactions: [0081] CH 3 O-PEG-O—CH 2 —COOH 5000 (3.0 g, 0.6 mmole), 2-(2-pyridyldithio)ethanol (342 mg, 1.5 mmole), DMAP (180 mg, 1.44 mmole) and HOBT (93 mg, 0.6 mmole) were dissolved in 60 ml of dichloromethane. To this solution was added DCC (138 mg, 0.66 mmole) in 5 ml of dichloromethane. The solution was stirred at room temperature under N 2 overnight. The solvent was removed by rotary evaporation and 15 ml of toluene was added to the residue. After all PEG dissolved, the solution was filtered to remove dicyclohexyl urea. To the solution was added 45 ml of methylene chloride and the solution was washed with sodium acetate buffer (0.1M, pH 5.0) which contained 10% sodium chloride. The organic phase was dried over anhydrous sodium sulfate, filtered to remove salt, condensed on a rotary evaporator, and precipitated into 100 ml of ethyl ether. The product was collected by filtration and dried in vacuo. Yield 2.85 g (95%). 1 H NMR (DMSO-d 6 ): δ 3.5 (br m, PEG), 4.11 (s, PEGOC H COO—), 4.30 (t, COOC H 2 CH 2 SS—) 7.29 (t, one aromatic proton), 7.77 (t+d, two aromatic protons), 8.46 (d, one aromatic proton). Example 10 [0000] Determination of Hydrolysis Half-Lives of the Ester Linkage [0082] Reactions: [0083] mPEG-CM-SSP and 20% PEG 20,000 (wt) (as internal standard) were dissolved in 10 mM phosphate buffer (pH 7.2) and a series of ampoules were sealed each containing about 0.25 ml of above solution. The ampoules were stored as two groups, one group at room temperature and the other at 37° C. At each measurement, one ampoule in each group was opened and the solution was analyzed. The concentration of mPEG-CM-SSP and its hydrolysis product were determined by HPLC-GPC (Ultrahydrogel 250 column, Waters; 5 mM phosphate bufer pH 7.2 as mobile phase). The hydrolytic half-life was obtained from the slope of the natural logarithm of C at the time t minus C at infinite time versus time, assuming 1st order kinetics. TABLE 3 Hydrolytic Half-Lives (Days) of the Ester in mPeg-CM-SSP (±10%) pH 5.5 pH 7.0 Room temperature 107 18 37° C.  20 2.9 Example 11 Preparation of CH 2 O-PEG-O(CH 2 ) n —CO 2 -PEG-OCOONHS [0084] Reactions: [0085] (a) Preparation of CH 3 O-PEG-OCH 2 CH 2 CO 2 -PEG-OBz [0086] In a 100 ml round-bottom flask, a solution of CH 3 O-PEG-O—(CH 2 ) n —CO 2 H (MW=2000, 2 g, lmmol) was dissolved in toluene and azeotropically dried for two hours. After slowly cooling to room temperature, the solution was added to thionyl chloride (3 ml, 6 mmole) in methylene chloride and then stirred under N 2 overnight. The solvent was then removed by rotary evaporation and the residual syrup was dried in vacuo for about four hours over P 2 O 5 powder. To the solid was added 5 ml of anhydrous methylene chloride and A solution (20 ml) (of azeotropically dried BzO-PEG-OH (MW=3400, 2.04 g, 0.60 mmol) in toluene To the resulting solution was added 0.6 ml of freshly distilled triethylamine and the solution was stirred overnight. The triethylamine salt was removed by filtration and the crude product was precipitated with ethyl ether and collected by filtration. The mixture was then purified by ion-exchange chromatography (DEAE sepharose fast flow column, Pharmacia). Pure CH 3 O-PEG-O— (CH 2 ) n-CO 2 —PEG-OBz was obtained. Yield: 2.6 g (80%). NMR (DMSO-d 6 ): δ 3.5 (br m, PEG), 2.55 (t, —OCH 2 C H 2 COOPEG-), 4.14 (s, —PEGOC H 2 COOPEG-), 4.13 (t, —PEGOCH 2 CH 2 —COOC H 2 CH 2 OPEG-), 4.18 (t, —PEGOCH 2 —COOC H 2 CH 2 OPEG), 4.49 (s, —PEG-O—C H 2 —C 6 H 5 ), 7.33 (s+com, —PEG-O—CH 2 —C 6 H 5 ). [0087] (b) Preparation of CH 3 O-PEG-O—(CH 2 ) n —CO 2 -PEG-OH [0088] A solution of 2 g of CH 3 O-PEG-O—(CH 2 ) n —CO 2 -PEG-OBz in 1,4-dioxane was hydrogenolyzed with H 2 (2 atm) on 1 gram Pd/C (10%) overnight. The catalyst was removed by filtration, the solvent was condensed under vacuum and the solution was added to ethyl ether. The product was collected by filtration and dried under vacuum at room temperature to yield: 1.5 g (75%) of CH 3 O-PEG-O—(CH 2 ) n —CO 2 —PEG-OH. NMR (DMSO-d 6 ): δ 3.5 (br m, PEG), 2.55 (t, —OCH 2 CH 2 COOPEG-), 4.14 (s, —PEG-OC H 2 COOPEG-), 4.13 (t, —PEGOCH 2 CH 2 COOC H 2 CH 2 OPEG-), 4.18 (t, —PEGOCH 2 —COOC H 2 CH 2 OPEG). [0089] (c) Preparation of CH 3 O-PEG-O— (CH 2 ) n —CO 2 -PEG-OCOONHS [0090] CH 3 O-PEG-O—(CH 2 ) n —CO 2 -PEG-OH 5400 (1.25 g, 0.23 mmole) was azeotropically distilled with 100 ml acetronitrile and then cooled to room temperature. To it were added disuccinimidyl carbonate (245 milligram, 0.92 mmole) and 0.1 ml of pyridine, and the solution was stirred at room temperature overnight. The solvent was then removed under vacuum, and the resulting solid was dissolved in 35 ml of dry methylene chloride. The insoluble solid was removed by filtration, and the filtrate was washed with pH 4.5 sodium chloride saturated acetate buffer. The organic phase was dried over anhydrous sodium sulfate, filtered, condensed by rotary evaporation, and precipitated into ethyl ether. The product was collected by filtration and dried in vacuo. Yield: 1.20 g (96%), 100% substitution of succimidyl carbonate and no reagent left. NMR (DMSO-d 6 ): δ 3.5 (br m, PEG), 2.55 (t, —OCH 2 C H 2 COOPEG-), 4.14 (s, —PEG-OC H 2 COOPEG-), 4.13 (t, —PEGOCH 2 CH 2 COOC H 2 CH 2 OPEG-), 4.18 (t, —PEGOCH 2 —COOC H 2 CH 2 OPEG), 4.45 (t, —PEGO-CH 2 C H 2 OCONHS), 2.81 [s, NHS]. [0091] The invention has been described in particular exemplified embodiments. However, the foregoing description is not intended to limit the invention to the exemplfied embodiments, and the skilled artisan should recognize that variations can be mad within the scope and spirit of the invention as described in the foregoing specification. On the contrary, the invention includes all alternatives, modifications, and equivalents that may be included within the true spirit and scope of the invention as defined by the appended claims.

PEG and related polymer derivatives having weak, hydrolytically unstable linkages near the reactive end of the polymer are provided for conjugation to drugs, including proteins, enzymes, small molecules, and others. These derivatives provide a sufficient circulation period for a drug-PEG conjugate and then for hydrolytic breakdown of the conjugate and release of the bound molecule. In some cases, drugs that previously had reduced activity when permanently coupled to PEG can have therapeutically suitable activity when coupled to a degradable PEG in accordance with the invention. The PEG of the invention can be used to impart water solubility, size, slow rate of kidney clearance, and reduced immunogenicity to the conjugate. Controlled hydrolytic release of the bound molecule in the aqueous environment can then enhance the drug delivery system.

BACKGROUND 1. Field of the Invention Gutter covering systems are known to prevent debris from entering into the open top end of a rain gutter. When debris accumulates within the body of a rain gutter in an amount great enough to cover the opening of a downspout-draining hole the draining of water from the rain gutter is impeded or completely stopped. This occurrence will cause the water to rise within the rain gutter and spill over it's uppermost front and rear portions. The purpose of a rain gutter: to divert water away from the structure and foundation of a home is thereby circumvented. 2. Prior Art The invention relates to the field of Gutter Anti-clogging Devices and particularly relates to screens with affixed fine filter membranes, and to devices that employ recessed wells or channels in which filter material may be inserted, affixed to gutters to prevent debris from impeding the desired drainage of water. Various gutter anti-clogging devices are known in the art and some are described in issued patents. U.S. Pat. No. 5,557,891 to Albracht teaches a gutter protection system for preventing entrance of debris into a rain gutter. Albracht teaches a gutter protection system to include a single continuous two sided well with angled sides and perforated bottom shelf 9 into which rainwater will flow and empty into the rain gutter below. The well is of a depth, which is capable of receiving a filter mesh material. However, attempts to insert or cover such open channels of “reverse-curve” devices with filter meshes or cloths is known to prevent rainwater from entering the water receiving channels. This occurrence exists because of the tendency of such membranes, (unsupported by a proper skeletal structure), to channel water, by means of water adhesion along the interconnected paths existing in the filter membranes (and in the enclosures they may be contained by or in), past the intended water-receiving channel and to the ground. This occurrence also exists because of the tendency of filter mediums of any present known design or structure to quickly waterproof or clog when inserted into such channels creating even greater channeling of rainwater forward into a spill past an underlying rain gutter. Filtering of such open, recessed, channels existing in Albracht's invention as well as in U.S. Pat. No. 5,010,696, to Knittel, U.S. Pat. No. 2,672,832 to Goetz, U.S. Pat. Nos. 5,459,350, & 5,181,350 to Meckstroth, U.S. Pat. No. 5,491,998 to Hansen, U.S. Pat. No. 4,757,649 to Vahldieck and in similar “reverse-curved” inventions that rely on “reverse-curved” surfaces channeling water into an open channel have been known to disallow entrance of rainwater into the water-receiving channels. Albracht's as well as previous and succeeding similar inventions have therefore notably avoided the utilization of filter insertions. What may appear as a logical anticipation by such inventions at first glance, (inserting of a filter mesh or material into the channel), has been shown to be undesirable and ineffective across a broad spectrum of filtering materials: Employing insertable filters into such inventions has not been found to be a simple matter of anticipation, or design choice of filter medium by those skilled in the arts. Rather, it has proved to be an ineffective option, with any known filter medium, when attempted in the field. Such attempts, in the field, have demonstrated that the filter mediums will eventually require manual cleaning. German Patent 5,905,961 teaches a gutter protection system for preventing the entrance of debris into a rain gutter. The German patent teaches a gutter protection system to include a single continuous two sided well 7 with angled sides and perforated bottom shelf which rainwater will flow and empty into the rain gutter below. The well is recessed beneath and between two solid lateral same plane shelves close to the front of the system for water passage near and nearly level with the front top lip of the gutter. The well is of a depth, which is capable of receiving a filter mesh material. However, for the reasons described in the preceding paragraphs, an ability to attach a medium to an invention, not specifically designed to utilize such a medium, may not result in an effective anticipation by an invention. Rather, the result may be a diminishing of the invention and its improvements as is the case in Albracht's U.S. Pat. No. 5,557,891, the German Patent, and similar inventions employing recessed wells or channels between adjoining planes or curvatures. U.S. Pat. No. 5,595,027 to Vail teaches a continuous opening 24A between the two top shelves. Vail teaches a gutter protection system having a single continuous well 25, the well having a depth allowing insertion and retention of filter mesh material 26 (a top portion of the filler mesh material capable of being fully exposed at the holes). Vail does teach a gutter protection system designed to incorporate an insertable filter material into a recessed well. However, Vail notably names and intends the filter medium to be a tangled mesh fiberglass five times the thickness of the invention body. This type of filtration medium, also claimed in U.S. Pat. No. 4,841,686 to Rees, and in prior art currently marketed as FLOW-FREE. TM. is known to trap and hold debris within itself which, by design, most filter mediums are intended to do, i.e.: trap and hold debris. Vail's invention does initially prevent some debris from entering an underlying rain gutter but gradually becomes ineffective at channeling water into a rain gutter due to the propensity of their claimed filter mediums to clog with debris. Though Vail's invention embodies an insertable filter, such filter is not readily accessible for cleaning when such cleaning is necessitated. The gutter cover must be removed and uplifted for cleaning and, the filter medium is not easily and readily inserted replaced into its longitudinal containing channel extending three or more feet. It is often noted, in the field, that these and similar inventions hold fast pine needles in great numbers which presents an unsightly appearance as well as create debris dams behind the upwardly extended and trapped pine needles. Such filter meshes and non-woven lofty fiber mesh materials, even when composed of finer micro-porous materials, additionally tend to clog and fill with oak tassels and other smaller organic debris because they are not resting, by design, on a skeletal structure that encourages greater water flow through its overlying filter membrane than exists when such filter meshes or membranes contact planar continuously-connected surfaces. Known filter mediums of larger openings tend to trap and hold debris. Known filter mediums smaller openings clog or “heal over” with pollen and dirt that becomes embedded and remains in the finer micro-porous filter mediums. At present, there has not been found, as a matter of common knowledge or anticipation, an effective water-permeable, non-clogging “medium-of-choice” that can be chosen, in lieu of claimed or illustrated filter mediums in prior art, that is able to overcome the inherent tendencies of any known filter mediums to clog when applied to or inserted within the types of water receiving wells and channels noted in prior art. Vail also discloses that filter mesh material 26 is recessed beneath a planar surface that utilizes perforations in the plane to direct water to the filter medium beneath. Such perforated planar surfaces as utilized by Vail, by Sweers U.S. Pat. No. 5,555,680, by Morin U.S. Pat. No. 5,842,311 and by similar prior art are known to only be partially effective at channeling water downward through the open apertures rather than forward across the body of the invention and to the ground. This occurs because of the principal of water adhesion: rainwater tends to flow around perforations as much as downward through them, and miss the rain gutter entirely. Also, in observing perforated planes such as utilized by Vail and similar inventions (where rainwater experiences its first contact with a perforated plane) it is apparent that they present much surface area impervious to downward water flow disallowing such inventions from receiving much of the rainwater contacting them. A simple design choice or anticipation of multiplying the perforations can result in a weakened body subject to deformity when exposed to the weight of snow and/or debris or when, in the case of polymer bodies, exposed to summer temperatures and sunlight. U.S. Pat. No. 4,841,686 to Rees teaches an improvement for rain gutters comprising a filter attachment, which is constructed to fit over the open end of a gutter. The filter attachment comprised an elongated screen to the underside of which is clamped a fibrous material such as fiberglass. Rees teaches in the Background of The Invention that many devices, such as slotted or perforated metal sheets, or screens of wire or other material, or plastic foam, have been used in prior art to cover the open tops of gutters to filter out foreign material. He states that success with such devices has been limited because small debris and pine needles still may enter through them into a rain gutter and clog its downspout opening and or lodge in and clog the devices themselves. Rees teaches that his use of a finer opening tangled fiberglass filter sandwiched between two lateral screens will eliminate such clogging of the device by smaller debris. However, in practice it is known that such devices as is disclosed by Rees are only partially effective at shedding debris while channeling rainwater into an underlying gutter. Shingle oil leaching off of certain roof coverings, pollen, dust, dirt, and other fine debris are known to “heal over” such devices clogging and/or effectively “water-proofing” them and necessitate the manual cleaning they seek to eliminate. (If not because of the larger debris, because of the fine debris and pollutants). Additionally, again as with other prior art that seeks to employ filter medium screening of debris; the filter medium utilized by Rees rests on an inter-connected planar surface which provides non-broken continuous paths over and under which water will flow, by means of water adhesion, to the front of a gutter and spill to the ground rather than drop downward into an underlying rain gutter. Whether filter medium is “sandwiched” between perforated planes or screens as in Rees' invention, or such filter medium exists below perforated planes or screens and is contained in a well or channel, water will tend to flow forward along continuous paths through cur as well as downward into an underlying rain gutter achieving less than desirable water-channeling into a rain gutter. U.S. Pat. No. 5,956,904 to Gentry teaches a first fine screen having mesh openings affixed to an underlying screen of larger openings. Both screens are elastically deformable to permit a user to compress the invention for insertion into a rain gutter. Gentry, as Rees, recognizes the inability of prior art to prevent entrance of finer debris into a rain gutter, and Gentry, as Rees, relies on a much finer screen mesh than is employed by prior art to achieve prevention of finer debris entrance into a rain gutter. In both the Gentry and Rees prior art, and their improvements over less effective filter mediums of previous prior art, it becomes apparent that anticipation of improved filter medium or configurations is not viewed as a matter of simple anticipation of prior art which has, or could, employ filter medium. It becomes apparent that improved filtering methods may be viewed as patenable unique inventions in and of themselves and not necessarily an anticipation or matter of design choice of a better filter medium or method being applied to or substituted within prior art that does or could employ filter medium. However, though Rees and Gentry did achieve finer filtration over filter medium utilized in prior art, their inventions also exhibit a tendency to channel water past an underlying gutter and/or to heal over with finer dirt, pollen, and other pollutants and clog thereby requiring manual cleaning. Additionally, when filter medium is applied to or rested upon planar perforated or screen meshed surfaces, there is a notable tendency for the underlying perforated plane or screen to channel water past the gutter where it will then spill to the ground. It has also been noted that prior art listed herein exhibits a tendency to allow filter cloth mediums to sag into the opening of their underlying supporting structures. To compensate for forward channeling of water, prior art embodies open aperatures spaced too distantly, or allows the aperatures themselvs to encompass too large an area, thereby allowing the sagging of overlying filter membranes and cloths. Such sagging creates pockets wherein debris tends to settle and enmesh. U.S. Pat. No. 3,855,132 to Dugan teaches a porous solid material which is installed in the gutter to form an upper barrier surface (against debris entrance into a rain gutter). Though Dugan anticipates that any debris gathered on the upper barrier surface will dry and blow away, that is not always the case with this or similar devices. In practice, such devices are known to “heal over” with pollen, oil, and other pollutants and effectively waterproof or clog the device rendering it ineffective in that they prevent both debris and water from entering a rain gutter. Pollen may actually cement debris to the top surface of such devices and fail to allow wash-off even after repeated rains. U.S. Pat. No. 4,949,514 to Weller sought to present more water receiving top surface of a similar solid porous device by undulating the top surface but, in fact, effectively created debris “traps” with the peak and valley undulation. As with other prior art, such devices may work effectively for a period of time but tend to eventually channel water past a rain gutter, due to eventual clogging of the device itself. There are several commercial filtering products designed to prevent foreign matter buildup in gutters. For example the FLOW-FREE .TM gutter protection system sold by DCI of Clifton Heights, Pa. Comprises a 0.75-inch thick nylon mesh material designed to fit within 5-inch K type gutters to seal the gutters and downspout systems from debris and snow buildup. The FLOW-FREE. TM device fits over the hanging brackets of the gutters and one side extends to the bottom of the gutter to prevent the collapse into the gutter. However, as in other filtering attempts, shingle material and pine needles can become trapped in the coarse nylon mesh and must be periodically cleaned. U.S. Pat. No. 6,134,843 to Tregear teaches a gutter device that has an elongated matting having a plurality of open cones arranged in transverse and longitudinal rows, the base of the cones defining a lower first plane and the apexes of the cones defining an upper second plane. Although the Tregear device overcomes the eventual trapping of larger debris within a filtering mesh composed of fabric sufficiently smooth to prevent the trapping of debris he notes in prior art, the Tregear device tends to eventually allow pollen, oil which may leach from asphalt shingles, oak tassels, and finer seeds and debris to coat and heal over a top-most matting screen it employs to disallow larger debris from becoming entangled in the larger aperatured filtering medium it covers. Tregear indicates that filtered configurations such as a commercially available attic ventilation system known as Roll Vent.RTM. manufactured by Benjamin Obdyke, Inc. Warminster, Pa. Is suitable, with modifications that accomadate its fitting into a raingutter. However, such a device has been noted, even in its original intended application, to require cleaning (as do most attic screens and filters) to remove dust, dirt, and pollen that combine with moisture to form adhesive coatings that can scum or heal over such attic filters. Filtering mediums (exhibiting tightly woven, knitted, or tangled mesh threads to achieve density or “smoothness”) employed by Tregear and other prior art have been unable to achieve imperviousness to waterproofing and clogging effects caused by a healing or pasting over of such surfaces by pollen, fine dirt, scum, oils, and air and water pollutants. Additionally, referring again to Tregear's device, a lower first plane tends to channel water toward the front lip of a rain gutter, rather than allowing it's free passage downward, and allow the feeding and spilling of water up and over the front lip of a rain gutter by means of water-adhesion channels created in the lower first plane. Prior art has employed filter cloths over underlying mesh, screens, cones, longitudinal rods, however such prior art has eventually been realized as unable to prevent an eventual clogging of their finer filtering membranes by pollen, dirt, oak tassels, and finer debris. Such prior art has been noted to succumb to eventual clogging by the healing over of debris which adheres itself to surfaces when intermingled with organic oils, oily pollen, and shingle oil that act as an adhesive. The hoped for cleaning of leaves, pine needles, seed pods and other debris by water flow or wind, envisioned by Tregear and other prior art, is often not realized due to their adherence to surfaces by pollen, oils, pollutants, and silica dusts and water mists. The cleaning of adhesive oils, fine dirt, and particularly of the scum and paste formed by pollen and silica dust (common in many soil types) by flowing water or wind is almost never realized in prior art. Prior art that has relied on reverse curved surfaces channeling water inside a rain gutter due to surface tension, of varied configurations and pluralities, arranged longitudinally, have been noted to lose their surface tension feature as pollen, oil, scum, Eventually adhere to them. Additionally, multi-channeled embodiments of longitudinal reverse curve prior art have been noted to allow their water receiving channels to become packed with pine needles, oak tassels, other debris, and eventually clog disallowing the free passage of water into a rain gutter. Examples of such prior art are seen in the commercial product GUTTER HELMET.RTM. manufactured by American metal products and sold by Mr. Fix It of Richmond, Va. In this and similar Commercial products, dirt and mildew build up on the bull-nose of the curve preventing water from entering the gutter. Also ENGLERT'S LEAFGUARD. RTM. Manufactured and distributed by Englert Inc. of Perthamboy N.J. and K-GUARD. RTM. Manufactured and distributed by KNUDSON INC. of Colorado are similarly noted to lose their water-channeling properties due to dirt buildup. These commercial products state such, in literature to homeowners that advises them on the proper method of cleaning and maintaining their products. None of theses above-described systems keep all debris out of a gutter system allowing water alone to enter, for an extended length of time. Some allow lodging and embedding of pine needles and other debris is able to occur within their open water receiving areas causing them to channel water past a rain gutter. Others allow such debris to enter and clog a rain gutter's downspout opening. Still others, particularly those employing filter membranes, succumb to a paste and or scum-like healing over and clogging of their filtration membranes over time rendering them unable to channel water into a rain gutter. Pollen and silica dirt, particularly, are noted to cement even larger debris to the filter, screen, mesh, perforated opening, and/or reverse curved surfaces of prior art, adhering debris to prior art in a manner that was not envisioned. Accordingly, it is an object of the present invention to provide a gutter shield that permits drainage of water runoff into the gutter trench without debris becoming entrenched or embedded within the surface of the device itself and that employs a filtration membrane configuration that possesses sufficient self-cleaning properties that prevent the buildup of scum, oil, dirt, pollen, and pollutants that necessitate eventual manual cleaning as is almost always the case with prior art. Another object of the present invention is to provide a gutter shield that employs a filtration membrane that is readily accessible and easily replaceable if such membrane is damaged by nature or accident. Another object of the present invention is to provide a gutter shield that better enhances the cosmetic appearance and blending of and with a building's rain gutter system than is offered by prior art. Another object of the present invention is to provide a gutter shield that will accept more water run-off into a five inch K-style rain gutter than such a gutter's downspout opening is able to drain before allowing the rain gutter to overflow (in instances where a single three-inch by five-inch downspout is installed to service 600 square feet of roofing surface). Other objects will appear hereinafter. SUMMARY It has now been discovered that the above and other objects of the present inventioin may be accomplished in the following manner. Specifically, the present invention provides a gutter shield for use with gutters having an elongated opening. Normally the gutters are attached to or suspended from a building. The gutter shield device comprises an extruded polymer uni-body of an angled first plane that rests on the front lip of a rain gutter and that adjoins a second downwardly angled perforated plane by means of a u-shaped channel that exists on the underside of the rear edge of said first plane. A second plane then joins to an upward vertical support leg that joins to a third perforated plane that angles downward (referenced to the rear wall of an underlying rain gutter) and inward toward the vertical leg. Second and third perforated planes thereby exibit an extended v-shaped configuration that directs water to the inward center of a rain gutter where it is then dammed by a vertical support leg that forces the water to pool upward and drop through perforations rather than channel past them. A fourth upwardly angled plane positioned above an behind the v-shaped configuration of planes two and three, joins to plane three by means of a u-shaped channel and vertical leg, joined to and beneath the forward edge of the u-shaped channel, that exists underside the forward (referenced to the front lip of a rain gutter) edge of plane four. The fourth plane has embedded in the center of its upper surface, a recessed channel to facilitate scoring and braking of the fourth plane. The fourth plane then joins to a rear vertical leg by means of a rear u-shaped channel. A filtration configuration is inserted in the extruded body of the gutter sheild device. The upper membrane of the filter configuration is comprised of smaller threads intersecting or adjoing larger ones at centermost points on the sides of the larger threads. The upper membrane thereby avoids presenting overlapping or underlapping thread joints that tend to trap and hold debris, while presenting a very water permeable surface that more readily lends itself to self-cleaning by way of flowing water. The upper membrane is sewn to the edges of an underlying skeletal structure that exhibits a strong siphoning action. The lower supporting skeletal structure beneath the upper membrane is comprised of ellipses spaced approximately 0.19 inch from end to end that have underlying vertical legs that join, at their lowest point, to a horizontal perforated surface that has underlying vertical extending legs. This combination of multiple elliptical surfaces so spaced, and of vertical planes above and beneath a perforated horizontal plane, exhibits strong tendencies to break forward water channeling, that often causes water to spill past a rain gutter, and redirect water downward and inward into an underlying rain gutter. The gutter sheild body may be inserted into and secured in a rain gutter by common methods now recognized as public domain. The filtration configuration is pinched on each lateral edge and then the edges are realeased into u-shaped edge receiving channels. The filtration configuration is supported in its center by an upward extending vertical leg that adjoins perforated planes two and three at their lowest edges. OBJECTS AND ADVANTAGES An object of the present invention is to provide a gutter shield device that employs a fine filtration combination that is not subject to gumming or healing over by pollen, silica dust, oils, and other very fine debris. Another object of the present invention is to provide a gutter shield body that can quickly and easily, in the field at the time of installation, be retrofitted with the current gutter coil employed in extruding the raingutters the present invention would be installed in. Another object of the present invention is to provide a filtration membrane that is not affixed to an underlying surface by adhesive means that tend to gum and trap debris in hot weather. Another object of the present invention is to provide a filtration configuration that does not allow its filter cloth or membrane to sag and develop debris catching pockets. Another object of the present invention is to provide a gutter shield device that disallows the entrance of debris into a raingutter in the event its removable filter requires replacement due to storm damage. Another object of the present invention is to provide a filtration configuration and encompassing body that eliminates any forward channeling of rain water. Another object of the present invention is to provide a filtration configuration that may more readily be inseted into or removed, if required, than has been realized in prior art. THE DRAWING FIG. 1 . is a partial or fragmentary sectional edge view of the present invention displaying the profile of the main body of the gutter cover as it would appear extruding from a die. FIG. 2 . is a partial or fragmentary top perspective view of the main body of the present invention. FIG. 3 . is a partial or fragmentary sectional edge view of a component of the present invention displaying the profile of a supporting skeletal filtration structure that is an insertable component employed by the present invention. FIG. 4 . is a partial or fragmentary top perspective view of the supporting skeletal filtration component employed by the present invention. FIG. 5 . is an enlarged isolated view of a filter medium which affixes to the supporting filtration skeleton component employed by the present invention. FIG. 6 . is a partial or fragmentary top perspective view of the completed filtering component of the present invention as it appears prior to insertion into a receiving channel of the main body of the present invention. FIG. 7 . is a partial or fragmentary sectional edge view of the present invention displaying the profiles of it's main body with filtration skeleton inserted. FIG. 8 . is a partial or fragmentary top perspective view of the preferred embodiment of the present invention displaying the main body of the gutter cover with inserted filtration skeleton and affixed (to the skeleton) filter medium. FIG. 9 . is a partial or fragmentary sectional view displaying the profiles of a roofline portion of a building structure, and shows an end view of a sectioned K-style gutter and a side or end view of an overlying and attached gutter cover section. FIG. 9 a . is a partial or fragmentary sectional view displaying the profiles of a roofline portion of a building structure, K-style gutter, attached gutter cover, and optional rear insertable filter medium. FIG. 10 . is a partial or fragmentary sectional view displaying the profiles of a roofline portion of a building structure, K-style gutter, attached gutter cover, and optional securing ledge. FIG. 11 . is a partial or fragmentary sectional view displaying the profiles of a roofline portion of a building structure, K-style gutter, attached gutter cover, and optional rear extension component. FIG. 11 a . is a partial or fragmentary top perspective view of an optional rear extension component of the present invention. FIG. 12 . is a partial or fragmentary top perspective view of the main body of the present invention and of an optional covering sleeve component. FIG. 12 a . is a partial or fragmentary top perspective view of the main body of the present invention and of an optional covering sleeve component slid onto the top shelf of the main body of the present invention. FIG. 13 . displays top perspective views of the main body of the present invention illustrating an optional width-adjustable element or feature of the gutter cover. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now specifically to the drawings, a gutter cover (protector) body 1 with an insertable “multi-level filter” 32 according to the present invention is illustrated in FIG. 8 . The gutter protector material is to be a polymer that is reduced to liquid form through screw compression of plastic “tags” or reduced to liquid form through other means. This liquid plastic mixture will then be extruded through a single block die embodying a profile of the body of the invention. The extruded material is rigid or semi-flexible PVC or Polypropylene or other heat, chemical, and UV resistant polymer. The preferred thickness of the extruded polymer material forming the gutter protector cover will range from 0.05 to 0.07 inches. The extruded material is suitably thick to maintain its shape and not deform or dip under load bearing weight of snow and ice or deform when exposed to high ambient temperatures which have caused prior art of lesser polymer thickness to deform vertically upwards and downwards allowing open-air gaps to form from one piece of prior art to the next when they rest abutted side by side. These gaps may allow debris entrance into a rain gutter. The PVC, Polypropylene, or other polymer will contain sufficient titanium oxide, carbon black, or other UV inhibitors to resist breakdown of structural integrity for a period of at least 10 years when exposed to normal cycles of “Florida Sun” (sunlight equivalent to that experienced over a 10 year period of outdoor exposure to weathering conditions in the state of Florida). The gutter protector body may be extruded in any length but it is preferred that the extruded body be cut into 4 to five foot lengths, at the point of manufacture, while exiting a plastics extrusion cooling tray. Such lengths may be installed by one individual while allowing for as few joints or seams as possible to exist when the present invention is installed over the length of a gutter. The extruded body is 5.4 inches wide. Referring to FIG. 10 it is illustrated that the extruded body will rest inside the topmost opening of a conventional K-style 5 or 6 inch rain gutter 33 supported by spikes or “hidden hangars” 28 upon which the rear horizontal leg of the body 20 rests and supported by the front lip of the K-style rain gutter upon which the front “lip” 9 of the extruded body rests, such front lip 9 having an approximate length of 0.757 in. FIG. 10 further illustrates the body may also be supported in the rear by affixing a flexible semi-concaved metal or plastic extrusion 27 (0.07 inches thickness or less) into the fascia board of a building structure and allowing it to extend outward away from the fascia board sufficient length to enable semi-concaved extrusion 27 to insert into the rear Channel 22 of the body to support the body at the rear. This may be desirable to ensure high winds may not uplift the extruded gutter cover out of the rain gutter as does occur with prior art. This may also ensure a level plane is created from one five length of the extruded body to the next at the rear in instances where reliance on gutter spikes for support of the rear portion of the extruded body may be inadvisable in instances where the gutter spikes may be driven at uneven heights through the rear of a rain gutter into a fascia board disallowing the extruded gutter cover 1 from maintaining a level horizontal plane between adjoining (abutted) pieces. A level plane from one gutter cover 1 to the next when installed inside a rain gutter is important to disallow vertical gaps from occurring between pieces as they may in prior art which may provide an entrance for debris into a rain gutter. The profile of the body of the gutter protector illustrated in FIG. 1 shows the extruded body includes a rear horizontal leg 20 approximately 0.4 inches in length which may serve to rest on a gutter spike or hidden gutter hangar for a length of at least 0.4 inches at point of contact which serves to distribute any weight upon the gutter cover body over a greater surface area of a supporting spike or hanger than a simple extension of rear leg 19 , whose approximate length is 0.6 in., would provide in the absence of rear horizontal leg 20 . FIG. 2 reference numeral 20 illustrates that a rear horizontal leg of the extruded body 1 is integral to the body and extends the entire length of the body and is perforated to allow rear drainage surface area in the event wind blown rain or melting ice flows rearward rather than forward into filtration membrane 32 . FIG. 9 illustrates that rear horizontal leg 20 also may serve as a locking mechanism due to its positioning beneath hex-head or other screw fasteners 30 used to secure a hidden hangar and rear of a rain gutter to a fascia board in such instances when hidden hangars are the chosen method of fastening. It can be seen in FIG. 9 a that rear horizontal leg 20 may also serve as a platform on which a mesh or other type filter 31 approximately ¾ inch to 1½ inch wide and one inch tall may rest to provide a rear barrier to debris that may possible be wind blown to the rear of the gutter protector body. Referring, again, to FIG. 1 it can be seen that the extruded gutter cover body includes a rear support leg 19 that serves to provide rear vertical support for the gutter cover body and which includes “score lines” 21 which an installer may score with a utility knife or other scoring device if necessary. Such scoring will prevent running cracks up the rear support leg 19 from occurring if the rear support leg should ever need to be notched out to fit over a gutter spike that may be positioned too high through or above the rear of a rain gutter. In practice, in the field, improper positioning of the gutter spike occurs infrequently and may cause the gutter cover body to rest unevenly at varying heights inside the rain gutter necessitating that the rear support leg 19 and rear horizontal leg 20 be notched out to allow the rear of the gutter cover body to rest in a lower position inside the rain gutter to maintain an attractive low profile and smooth even-plane transition from section to section of the body of the present invention. Referring again to FIG. 1, rear support leg 19 of the extruded body extends vertically upwards at an approximate 85-degree angle and an approximate 0.6-inch length. Support leg 19 then bends forward at approximately a 75 degree to 95-degree angle to form a shelf 23 approximately 0.2 inches in length. Shelf 23 extends upward approximately 90 degrees forming vertical leg 18 with an approximate length of 0.21 inches. Vertical leg 18 then angles forward approximately 90 degrees into a higher shelf 17 whose approximate length is 0.3 inches. Referring now to FIG. 10 it is seen that bottom shelf 23 , vertical leg 18 , and higher shelf 17 of the extruded body form a recessed “receiving” channel 22 approximately 0.2 inches in depth and 0.07 inches wide which may serve to receive plastic or metal inserts or fasteners 27 that may be used to create a rear to forward tension mount of the extruded body. Referring now to FIGS. 12 and 12 a , it is illustrated that channel 22 may additionally may serve to act as a the first of two receiving channels of the extruded body, the second receiving channel being channel 23 that may receive and hold fast and permanently an aluminum, zinc, or copper metal cover 35 that may be clipped onto the extruded body. This clipped on cover 35 may serve to join two extruded body pieces together by spanning and covering the joint formed at their side-by-side abutment when such pieces are installed in a rain gutter. This clipped on cover 35 may further serve to provide fungicidal properties when made of zinc that would discourage moss mold or mildew growth on the invention, which is an improvement, not found in prior art. The clipped on cover 35 may further serve to allow color and material matching of the plastic extruded body to aluminum, copper, and other metal rain gutters which is an advantage and property not found or suggested in prior art. The co-use of two such materials, polymer and metal, in a leaf guard on copper or other expensive metal rain gutters would provide a great economical alternative to the use of solid copper leaf guards which naturally employ thicker and thereby more expensive copper in their design. The dimensions of such an extruded 0.019 or thinner metal cover would be such that it's underside 36 would be approximately 5 percent to 15 percent greater than the exterior portion of the extruded plastic body of the invention it covers. Such extruded metal cover may also serve to act as an extension for the plastic extruded body it covers to allow for a fit rain gutters larger than standard 5″ K style gutters by widening the clip on metal shelf 35 to accommodate 6 inch or wider rain gutters. Referring again to FIG. 1, shelf 17 extends horizontally 0.3 in. and then upward into a curve 2 a such curve having an exterior radius of approximately 0.137 and an interior radius of approximately 0.073 inch. The reverse of curve 2 a of the extruded body extends forward in a somewhat horizontal plane 2 angled downward approximately 5 degrees for a distance of approximately 1.5 to 1.75 inches. Horizontal plane 2 embodies a small recessed channel 59 across its entire length of sufficient depth to allow for scoring and breaking of the horizontal plane. FIG. 13 illustrates such scoring and breaking of recessed channel 59 may be optionally employed by the installer in instances where a horizontally compressed rain gutter does not allow for easy installation of the invention: the severed rear portion of the extruded body 36 may then be placed over the front severed portion of the extruded body 37 as illustrated in FIG. 13 and affixed by polymer cement or fasteners such as plastic bolt 38 and plastic nut 39 creating such overlap distance of the rear severed portion of the extruded body over the front severed extrusion of the severed body as the installer deems necessary to create an ideal adjusted extruded body width for placement in a horizontally compressed portion of a rain gutter. Referring again to FIG. 1, Horizontal plane 2 , after extending a distance of approximately 1.5 inches, will then “fork” into two extensions: one extension; 3 , continues to extend outward angled downward from the 1.5 inch point an additional 5 to 10 degrees to form a top shelf approximately 0.28 inch in length. The other extension 4 of Horizontal plane 2 extends downward at an approximate 85 degree angle for a distance of 0.125 inches and then angles forward 90 degrees into a plane 16 approximately 0.28 inches in length. Extension 3 extension 4 and plane 16 form a recessed “receiving” channel 24 with a depth of approximately 0.28 inch and a width 55 of approximately 0.125 inch which serves to secure the edge of the multi level filter portion of the invention and to receive, if opted for, the curved edge of a metal cover which may be clipped onto Curve 2 a , Horizontal plane 2 , and extension 3 as illustrated in FIG. 12 a. Referring again to FIG. 1; Plane 16 of the extruded body continues and then angles sharply downward at an approximate 80 to 85 degree angle for a distance of approximately 0.4 inches to form plane 5 . Plane 5 extends downward and then angles forward at an approximate 22-degree angle-forming plane 15 . Plane 15 has an approximate length of 0.94 inch and is perforated as illustrated in FIG. 2 with perforations 0 approximately 0.065 inch wide, 0.125 long. Perforations 0 are aligned end-to-end and spaced approximately ¼ inch apart in rows, which extend the length of the extruded body, such rows being spaced approximately 0.145 inch apart. Referring again to FIG. 1, Plane 15 forks into an extension and a continuance: the extension of plane 15 is plane 6 which extends upwards as an extension of plane 15 at an approximate 90 degree angle. Plane 6 will act as a support for the insertable filter portion of the invention and presents an improvement not found in prior art in that it will act as a dam that forces water to back up and drip through the rear most rows of perforations of plane 15 rather than continue forward with enough speed and depth of water flow to spill over the front lip of the rain gutter. Such occurrence of water spill is common in prior art, which relies solely on water adhesion principals. Planes 5 , 15 , and 6 of the extruded body form a water receiving well with a perforated bottom shelf 15 that will direct water into a rain gutter when acting in conjunction with the water dam formed by plane 6 as described in the preceding sentence. Referring again to FIG. 1, Plane 15 , in addition to forking upwards into plane 6 also continues on at an approximate 22 degree upward angle beginning at the base of Plane 6 and extends into a perforated plane 13 approximately 0.95 inch long. This angling upward of plane 13 toward the front lip of the gutter presents an improvement not found in prior art in that water which contacts plane 13 will not continue on a forward flow toward the top front lip of a rain gutter due to water adhesion principals where it may then spill outside the rain gutter. Instead, the water that contacts plane 13 will follow the downward angling plane 13 and be more surely and intentionally directed into a rain gutter. The perforations of plane 13 are identical to those of plane 15 : 0.065 inch wide, 0.125 long, each perforation spaced end to end approximately 0.25 inches aligned in rows the length of the extruded body such rows being spaced approximately 0.145 inch apart. Plane 13 extends forward approximate 0.95 in and then angles downward approximately 16 degrees into plane 12 . Plane 12 extends forward approximately 0.33 inch at which point it forks into an extension and a continuance: the extension, plane 7 forks upward at an approximate 80 degree angle for a distance of approximately 0.14 inch at which point plane 7 terminates in a “T” configuration. The “T” configuration has a rearward (toward the rear of the extruded body) horizontally extending section, plane 8 , having a length of approximately 0.25 inch. Receiving channel 24 a is formed by planes 12 , 7 , and 8 and such channel has an approximate width 56 of 0.125 inch. This channel acts to receive and secure the forward edge 54 of supporting skeletal filter component 57 as illustrated in FIG. 8 . The forward extension of the “T” is an extending plane, 9 , that angles approximately 7 degrees downward for a distance of approximately 0.757 inch where it then angles downward 45 degrees into plane 10 , which measures approximately 0.45 inch in length. The continuance of plane 12 is for a distance of approximately 0.24 inches after its vertical fork; plane 7 giving plane 12 a total length of 0.57 inch. Referring again to FIG. 1 it may be seen that planes 6 , 13 , 12 , 7 , and 8 form a receiving well of the extruded body which will direct rain water through its perforations into a rain gutter. FIG. 1, planes 12 , 7 , and 8 further illustrate a recessed receiving channel 24 that may receive and secure both an inserted edge of the multi filter employed by the invention as is illustrated in FIG. 7 and FIG. 8 . FIG. 12 a illustrates that a “clip on” metal cover 40 may be inserted over planes 8 , 9 , and 10 to achieve an optional aesthetic matching of colored aluminum or copper between the present invention and the underlying gutter it protects and/or to achieve the improvements previously described in the last sentence of page 4 and the fist sentence of page 5 of this disclosure. FIG. 11 illustrates Channel 22 may serve as a receiving channel for polymer, metal, or other semi-flexible formed or extruded inserts with profiles similar to extension 41 which may be placed or affixed with adhesives into Channel 22 and may then serve as an extension of the extruded body 1 which extends rearward and compresses against the rear wall of a rain gutter, hidden hangar, or fascia board to create a rear to forward tension mount of the extruded body into the rain gutter at the discretion of the installer. The amount of mounting tension created may be varied by the length of the top shelf 42 of the extruded or formed extension 41 . Referring now to FIG. 3 there is illustrated the profile of a perforated filter skeleton 43 . The width of filter skeleton 43 is approximately 2.5 inches and is an extruded polymer of approximately 0.04 to 0.06 inches. Plane 44 is approximately 0.58 inch and contains perforations 0 , such perforations being of elliptical shape approximately 0.45 inches long and 0.22 inch wide. The perforations 0 are positioned as close to vertical leg 45 as possible and have a wider top opening than bottom creating a taper which more readily captures and directs rain water than a simple straight through punch. Horizontal plane 44 t-junctions into vertical leg 45 whose approximate length is 0.35 inch. Leg 45 has a curved bottom 46 , such curved surface facilitating the dropping of water off of leg 45 downward into the rain gutter. Leg 45 is capped by ellipse 47 . Ellipse 47 has dimensions of approximately 0.13 inch width and 0.08 inch height. The elliptical curved surfaces 47 resting on vertical legs 45 , create water-channeling paths that exhibit siphoning effects stronger than has been realized in prior art. These “t” configurations, as well as their approximate spacing of 0.19 inch from subsequent ellipses and legs, create act as an ideal support for warp-knitted filter membrane 50 (shown in FIG. 5 in an exploded view): Such “t” configurations, and their spacing, enhance the self-cleaning properties inherent in filter membrane 50 . Additionally, they present a breaking of any water channeling paths to the front of a rain gutter lip noted in prior art. FIG. 6 illustrates that filter membrane 50 will be affixed to filter skeleton 43 . The downward curves and spacing of the ellipses 47 offer an improvement over prior art in creating multiple curved surface water channels that direct toward a vertical leg resting on a horizontal perforated plane that employs downward extending legs to continue the flow of water downward rather than forward. This configuration creates stronger siphoning action than is created in prior art relying on elliptical ocean-wave shapes to channel water or downward extrusions positioned beneath perforations or screens. The channeling of water almost fully around an ellipse that is broken by a vertical downward extending leg better captures water and directs it downward preventing back-flow of received water against incoming water noted in prior art. Vertical legs 45 downward extensions beneath planes 44 and 48 ensure the water adhesion of flowing rain water is broken at the most opportune moment to ensure the directed flow of water into a rain gutter. Perforated planes 48 are approximately 0.25 inches in width. Viewing from right to left, the extruded filter skeleton continues from the first vertical leg 45 whose length is approximately 0.35 inch into an upward extension where it terminates into an ellipse 47 . Vertical leg 45 is intersected approximately 0.2 inch down by forward extending perforated horizontal plane 48 . Planes 48 are approximately 0.25 inches in length. Perforated plane 48 continues forward until it intersects the second vertical leg 45 approximately 0.2 inch below ellipse 47 . Vertical leg 45 extends approximately 0.22 inch downward from perforated plane 48 in order to break any surface tension of water adhering to perforated plane 48 and redirect it downward into a rain gutter. A second perforated plane 48 extends forward horizontally from a second vertical leg 45 until it intersects a third vertical leg 45 . Third vertical leg 45 is capped by an ellipse 47 as are all vertical legs of filter skeleton 43 . A third perforated plane 48 extends forward horizontally from third vertical leg 45 until it intersects a vertical leg 51 whose length from ellipse 47 to it's lower most surface 46 is approximately 0.45 inch. A fourth perforated plane 48 extends forward horizontally from vertical leg 51 for a distance of approximately 0.25 inch where it then right angles upward into a vertical leg 54 whose approximate length is 0.2 inch. Vertical leg 54 extends upward into an ellipse 47 . Directly beneath the ellipse which caps vertical leg 54 , a horizontal perforated plane 55 extends forward for a distance of approximately 0.45 inch. Planes 44 and 52 each have the endmost section of their length non-perforated to allow space for a sewing seam. filter membrane 50 will be sewn onto filter skeleton 43 at these endmost sections of planes 44 and 52 . Referring to FIG. 3 and viewing supporting skeletal component 57 left to right: each combination left to right of ellipse 47 , vertical leg 54 , perforated plane 48 , vertical leg 51 , ellipse 47 and of ellipse 47 , vertical leg 51 , perforated plane 48 , vertical leg 45 , ellipse 47 and of ellipse 47 , vertical leg 45 , perforated plane 48 , vertical leg 45 , ellipse 47 creates water receiving wells whose components (by means of their structural configuration and spacing) act to slow the flow of rainwater as well as capture and direct rain water downward into a rain gutter in an improved manner over prior art. It can be seen in FIGS. 3 and 4, that planes 44 and 52 are positioned on higher planes than planes 48 . This is done to allow the top of the elliptical planes 47 to remain on a level or slightly recessed plane with planes 3 and 8 of the extruded body as illustrated in FIG. 11 . This will disallow a damming effect that could lead to debris build up behind the insertable filter and encourage debris to fall or be wind blown off of the invention. It can also be seen in FIG. 11 that, viewing from right to left, the third vertical leg 45 abuts the upward extending leg 6 of the extruded body. This feature discourages the product from shifting. Referring again to FIG. 3 it can be seen that, viewing from right to left, the forth leg 51 is of greater length than the preceding downward extending legs 45 . The length of leg 51 is approximately 0.48 inch. This illustrates that the length of legs may vary to prevent forward flow of water to the front of the gutter by decreasing water tension paths along the bottom of the filter membrane. The ellipses, too, may exist at different planes which would further facilitate the capturing of rainwater and the direction of it downward into the rain gutter. Referring again to FIG. 3 it is seen that vertical leg 54 does not extend beneath perforated plane 48 . The reason for this is illustrated in FIG. 7 where it is seen that extending vertical leg 54 beneath the plane 48 would cause the filter skeleton to rise above a level or slightly recessed plane than exists between 3 and 8 of the extruded body. An extension of vertical leg 54 beneath perforated plane 48 would cause it to contact plane 13 and push the filter skeleton upwards. The vertical height of vertical leg 54 is approximately 0.17 inches from its bottom most surface up to the point it contacts ellipse 47 . FIG. 5 is an exploded view of filter membrane 50 , the type of filtration fabric illustrated affixed to filter skeleton 43 as illustrated in FIG. 6 . It can be seen in FIG. 5 that small cylindrical threads of polymer extrusion 55 are made to pass through larger threads 56 . This unique method of fabric formation offers an improvement over prior art in that this configuration of smaller curved surfaces passing through, rather than woven or knitted above and beneath larger threads, increases the fabric's ability to capture and direct water. This method of fabric formation offers another improvement over prior art in that it encourages dirt and debris to be less likely to be retained by the fabric and therefore less likely to clog the filtration cloth than other filters employed in prior art: woven, weaved, knitted, non-woven lofty, are able to accomplish. The largest distance between any two larger threads is to be less than {fraction (8/100)} of an inch, which prevents the smallest of debris from lodging within an open (space between threads. The preferred embodiment of this invention is illustrated in FIG. 9 and FIG. 12 a .: An extruded polymer body with extruded multi level filter that employs water receiving channels framed by curved ellipses resting on vertical supporting, lower extending legs covered by a filtration cloth as illustrated in FIG. 5 and FIG. 6 with a slide on or clip on metal covers as illustrated in FIG. 12 a. Operation of the Main Embodiment Referring to FIG. 9, there is illustrated the present invention: a gutter protection system that consists of a main body 1 and an insertable filter skeleton 43 covered with a filter membrane 50 . Filter Membrane 50 is composed of intersecting threads. (An exploded view of the interconnecting structure of the threads is illustrated in FIG. 5 ). Referring to FIG. 10 The present invention is illustrated as inserted into the top water receiving opening of a k-style rain gutter 33 and resting on a gutter hangar 28 . It is illustrated that the present invention rests wholly beneath the sub roof 60 and roofing membrane 61 of a building structure. Referring to FIG. 12, it is illustrated that the present invention will be affixed to an existing rain gutter in two stages. First, a main body 1 will be placed inside the open top of a rain gutter and then may be secured in place by several means: Rear horizontal leg 20 will rest upon a hidden hangar 28 and prevent body 1 from displacing by locking beneath the head of fastening screw 30 . The front of the present invention is snapped into place and secured to the front lip of the k-style gutter by planes 9 , 7 , & 11 of the body. Sub-heading 1 Covering of Joints, Aligning of Adjoining Sections, and Color Matching Once this is accomplished, main body 1 offers improvement over prior art in offering a method of aligning adjoining sections of the invention in a manner that allows joints between adjoining body members to be covered. This covering of joints and joining of abutted sections of the invention is accomplished by means of a roll-formed or “braked” sleeve (see FIG. 12 and 12 a , sleeve 35 ). The resulting absence of debris-allowing joints is not realized in prior art intended to retrofit existing rain gutters. Referring FIG. 1, there is illustrated a recessed channel 22 . Recessed channel 22 acts as the first of two receiving wells 22 & 24 for a roll-formed or job-site “braked” metallic cover 35 which may be clipped onto the top shelf 2 of the present invention (see FIGS. 12 & 12 a ). This feature offers improvement over prior art in that no prior art offers the ability to specifically color match to it's underlying rain gutter at the time of installation. The present invention allows the installer to quickly break matching gutter coil to clip into and cover top shelf 2 and top shelf 9 as is illustrated in FIG. 12 a . Metallic sleeves 35 & 40 may also serve to further align each sectioned body of the present invention and maintain consistent edges and heights between adjoining bodies. This is an optimal method of ensuring consistency of height and edge alignment between adjacent sections not known in prior art. Sub-heading 2 Vertical Height and Horizontal Width Adjustments Another improvement achieved by the present invention, not known in prior art, is its ability to provide a means of extending body width to accommodate standard sized commercial sized gutters with 4, 5, 6, and 7 inch widths. Widening may be accomplished by breaking or rollforming the metal cover 35 (FIG. 12 a ) to a width wide enough to effectively extend the present invention's body rearward. Sub-heading 2a Vertical Adjustments In the event body 1 is installed in a rain gutter affixed to a fascia board by gutter spikes, the present invention offers an improvement not found in prior art by offering a quick, at-the-point-of-installation, method of adjusting the height of the body to ensure it remains consistent. The body 1 of the present invention offers improvement over prior art by allowing for adjustment of it's rear vertical leg 19 by scoring and breaking of the rear leg at points 21 . It is known gutter spikes, often employed to secure a rain gutter to a fascia board, are driven in and remain at uneven heights at the rear of the rain gutter. Prior art, which requires a supporting of a rear leg or rearward part of invention body, has not foreseen or allowed for simple height adjustments to be made, which would accommodate prior art bodies to supporting, gutter spikes. Such adjustments may be necessary to maintain a consistent level height of gutter protection units for cosmetic as well as functional reasons. The improvement accomplished by the present invention is that such height adjustment may be accomplished quickly at the point of installation with a simple blade (to score point 21 ) and pair of scissor snips to clip the rear leg structure from rear horizontal leg 20 up through rear vertical leg 19 to the scored recess 21 . The scored mark ensures that the portion of rear vertical leg 19 so scored and cut will break off easily. Prior art does not allow for such simple controlled height adjustment at the point of installation (possibly while the installer is on an extension ladder). Sub-heading 2b Width Adjustments The body 1 of the present invention offers another improvement over prior art designed to be inserted into the top of a rain gutter, rather than rest upon the top surface of a subroof or roofing membrane, such as U.S. Pat. No. 6,134,843 to Tregear, U.S. Pat. No. 5,619,825 to Leroney, etc,. by allowing for adjustment of the main body by means of a pre-scored recessed channel 59 (FIGS. 2 & 13 ). Scoring of channel 59 allows the clean breaking and refastening of the body 1 to achieve a means of adjusting the present invention to accommodate both 4 inch and 5 inch gutters. FIG. 13 illustrates that the body 1 of the present invention may broken, then rejoined in a fashion that creates shorter body widths to accommodate the varying widths of a single run of gutter length. It is known that lengths of installed gutter seldom maintain a consistent width due to irregularities in fascia boards they are attached to. Prior art such as is illustrated in U.S. Pat. No. 5,495,694 to Kuhns, U.S. Pat. No. 5,459,965 to Meckstroth, etc., that require a resting of their body on top of or directly beneath shingles or other roofing materials do not have an intrinsic ability to accommodate varying gutter widths. This leads to such prior art presenting an uneven appearance along their rear edges which varies with the uneven width of a gutter they are attached to. This unevenness of edges at the rear of such products, as well as the dipping of subroof structures that often occur beneath the shingles such prior art may rest upon or be affixed to, allows open air spaces to exist at the rear of such products or from side-edge to side-edge of adjoining pieces. Debris may then enter through into a rain gutter or become trapped in the open air spaces. Because this problem is known, installers of prior art are known to screw the rear of such products into their underlying supporting roof structure, which can present the potential for roof leaks and the voiding of roofing manufacture warranties. Prior art has offered limited adjustment of width, usually by relying on body tension to extend width, as illustrated in such prior art as U.S. Pat. No. 5,619,825 to Leroney, but such extension of body width found in prior art is meant only accommodate one gutter width i.e.: 5 inch or 6 inch and does not allow for utilization of prior art over a span of varying standard gutter widths. Added width of span accomplished by tension weakens the strength of such invention's affixture to the raingutter since the pressure of tension is weakened. Prior art does not allow for the shrinking or widening of body width offered by the present invention in such fashion as to allow installations on narrower gutter widths than 5 inch or as to allow consistently secure installations on wider gutter widths than 5 inch. Prior art that does allow for installation on varying standard gutter widths such as is found in U.S. Pat. No. 5,660,001 to Albracht and U.S. Pat. No. 5,640,8090 etc, is undesirable because of the required securing of such prior to or beneath roofing membranes, which has been found to cause failures of roofing membrane integrity. Sub-heading 3 Water Receiving Wells Referring again to FIG. 2 it is illustrated that the body 1 incorporates two recessed perforated planes 13 & 15 , separated by a vertical leg 6 . Both planes angle downward and inward into the body of an underlying raingutter. This allows the present invention to offer improvement over prior art as follows: Referring to FIG. 1 : there is illustrated two recessed water-receiving perforated wells 15 and 13 , which direct water, flow downward to a vertical leg 6 . The downward angle of perforated well 13 , away from the front lip 9 and front lip of a rain gutter offers improvement over prior art U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear, and other prior art in that it forces water to cease any forward flow to the front of a rain gutter where it may spill past the raingutter as has been noted in prior art. Prior art has not effectively dealt with this noted problem. Reverse curved and hooded gutter protection methods such as U.S. Pat. No. 5,491,998 to Hansen do redirect water flow rearward into the raingutter but have not recognized the noted tendency of debris to follow the water around the curved surfaces they employ into the rain gutter as well. Additionally, such prior art is known to lose most of it's water adhesive properties over time as pollen, oil leaching from asphalt shingles, and other pollutants, coat and remain on the curved surfaces such prior art employs. Downward sloping plane 15 , also, prevents forward flow and resulting spilling of water to the ground, by acting in conjunction with vertical leg 6 . Vertical leg 6 , serves the dual purpose of acting as a center and downward water channeling support for the filtration membrane 50 and Skeleton 43 (See FIG. 9 ), and as serving as a dam that slows forward rushing water in recessed well 5 , 15 , 6 to slow and drain through the perforated plane 15 . Sub-heading 4 Filter Membrane and Skeleton Once installation and, if necessary, adjustment of the body and/or covering of the body 1 of the present invention is achieved, a filter membrane and skeleton will then be inserted into the recessed channel of the present invention. (See FIG. 2, then FIG. 8 and FIG. 9 ). Several improvements over prior art are offered by the filter membrane and skeleton employed by the present invention: Sub-heading 4a Filter Skeleton Referring now to FIG. 3 there is illustrated a filter member: a multi-level supporting structure upon which a wire or cloth membrane composed of intersecting threads shall rest. Prior art employing filtration cloth or membrane, which rests over open apertures e.g.: U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear, etc. exhibits a property of preventing rainwater from entering the open apertures beneath the filtration cloth. In practice, in the field, it is often observed that volumes of water will travel around the underlying perforations, beneath the filter cloth or membrane covering them, due to water adhesion principals. The water will then feed toward the front of prior art, rather down beneath it and into a rain gutter, and will flow past the top front lip of a rain gutter. This common occurrence in prior art occurs for several reasons. Perforated surfaces existing in a single plane, such as is employed in U.S. Pat. No 5,595,027 to Vail, or as exists in the Commercial Product SHEERFLOW. RTM. Manufactured by L. B. Plastics of N.C., and similar prior art tend to channel water inventions sought to correct this undesirable property by either tapering the rim of the open perforation and/or creating downward extensions of the perforation (creating a water channeling path down through open air space) as exhibited in prior art U.S. Pat. No. 6,151,837 to Ealer, or by creating dams on the plane the perforations exist on, as exhibited in prior art U.S. Pat. No. 4,727,689 to Bosler. Such prior art has been unable to ensure all water would channel into the underlying rain gutter because the water, that did, indeed, travel through the open apertures on the top side of these types of perforated planes or screens, would also travel along the underside of the screen wires or perforated planes, as it had on top of these surfaces, and still continue it's undesirable flow to the front of the invention and front lip of the underlying rain gutter, due to water adhesion. Additionally, this “underflow” of water on the underside of the perforated planes and screens illustrated in prior art exhibits a tendency to “back flow” or attempt to flow upwards through the perforations inhibiting downward flow of water. This phenomenon has been noted in practice, in the field when it has been observed that open air apertures appear filled with water while accomplishing no downward flow of water into the underlying rain gutter. Other inventors sought to eliminate this undesirable property by employing linear rods with complete open air space existing between each rod, This method of channeling more of the water into the rain gutter exhibits more success on the top surface of such inventions, but it fails to eliminate the “under channeling” of rainwater toward the front of the invention due to the propensity of water to follow the unbroken interconnected supporting rods or structure beneath the top layer of rods. Referring again to FIG. 3, the structure of the present invention improves the flow of water into the rain gutter over prior art, significantly, as has been observed in practice, in the field. This improvement is accomplished by allowing cylindrical rods 47 , with unbroken air space existing between them, to rest upon vertical leg supporting structures, which disallow any connecting path for forward water channeling due to water adhesion. Supporting structures 45 , 46 , 51 , & 54 are, indeed, each connected to the other by perforated planes 48 . However, this connection is broken by several factors, which disallow a forward flow of water. Water, instead, is forced downward into the rain gutter with no water adhesive path toward the front of the invention existing. This is accomplished by resting the rods 47 on slim vertical supports 45 , 46 , 51 ,& 54 . Doing so creates a “t” configuration unlike the simple rod structures of prior art. The present invention is an improvement in two instances: First, water that channels around simple rods, rather than “t” structures exhibits less siphoning action due to the water colliding on the underside of the rod after traveling down the opposing curved sides of the rod. This collision of water slows downward water flow by creating a back flow or upward flow of water against the rainwater attempting to channel downward along the curved surfaces of the rod. The “T” configuration of the present invention prevents such reverse flow or back flow of water against the incoming water flow by creating a continuing path of water flow away from water traveling down the opposite side of the “t”. This allows the filter skeleton 43 to create a stronger channeling or siphoning action on the incoming rainwater than prior art is able to exhibit. The “t” configuration also offers improvement over prior art because it creates an absolute break in the water adhesion flow on the bottoms of vertical legs 45 , 46 , 51 , & 54 . Water which will travel down rods 47 , then though the open air apertures 0 which exist in planes 48 , will next adhere to and travel down the lower (beneath planes 48 ) portions of the vertical legs of the “t”. Water traveling down the vertical legs, at this point, is an improvement over prior art such as U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear, because it has discontinued it's forward flowing path on the underside of the perforated plane, as is common in the prior art, and is now being channeled, again, downward toward the inside of the rain gutter. Prior art, U.S. Pat. No. 4,745,710 also temporarily accomplishes this downward flow utilizing it's rod-supporting structure, but not nearly as effectively due to the interconnection of the underlying support structure, which provides a forward flowing water path by means of water adhesion along an unbroken surface. The improvement of the “t” configuration over prior art is again accomplished by a third, completely disconnected path of water flow, achieved at the lower termination of the vertical legs 45 , 46 , 51 , & 54 . Water, at these points, may only flow downward into the rain gutter. This is due to the length of the downward extensions of the vertical legs, which, by design, disallow backflow of water on the underside of the perforated planes 48 , or forward flow of water along a water adhesion path to the front lip of the rain-gutter. Filter Skeletal structure 43 of the present invention creates a siphoning action and ensures a downward, rather than forward flow of water not exhibited by prior art. Referring to FIG. 5 there is illustrated a cloth or wire filter membrane 50 , which employs intersecting threads. This membrane exhibits an improvement over other filtering and screening methods illustrated, representatively, in prior art U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear, etching that it exhibits no tendency to trap and hold debris. The above mentioned prior art, even when employing micro-aperatured cloth, (due to adhesive actions of pollen, oil, pollutants, and silica dust which tend to heal over such products and remain impervious to cleaning by wind or water) has been observed, in the field, to clog due to tendencies to trap and hold debris, thereby channeling water past, rather than into the under lying rain gutter. Sub Heading 4b Filter Membrane Prior art, though naming filtering medium as cloth or screen or tangled mesh, has not recognized or utilized the improvements offered by a filtering membrane accomplished by the intersection of material of equal or larger and smaller wire, or cloth, or plastic thread configurations as is illustrated in FIG. 5 . Filtering and screening methods illustrated in prior art attempted to improve the propensity of reverse-curved or hooded gutter protection systems illustrated in prior art U.S. Pat. No. 5,557,891 to Albracht, and similar inventions, to trap and hold debris within their open channels. When this has occurred, water has flowed past the clogged open channels and to the ground due to waters tendency to bridge over debris trapped in a concave aperture. When debris rests on planar surfaces, water will travel beneath, rather than bridge over them, and attempt to travel through any open-air openings or apertures that exist beneath the debris. Filter and screening methods of gutter protection, however, illustrated in prior art have employed woven or knitted or mesh fibers or wires which intrinsically contain numerous joints, which tend to trap and hold debris. Filtering cloths, screens, and meshes are known to trap and hold debris to protect a medium on the other side of the filter. Screens, too, are known to trap and hold debris. When any of these methods of gutter protection have been employed in prior art, such inventions have been known to trap and hold debris reducing the amount of water that is able to enter an underlying rain gutter regardless of the porosity and/or density of the filter medium. The present invention exhibits no tendency to trap and hold debris, or dirt, or pollen and thereby offers a significant improvement over prior art. The present invention offers an improvement over prior art in that it's filtering membrane 50 , offers far fewer under and over knitted or woven or meshed joints for debris to become lodged within. The present invention also offers improvement over prior art in the existence of a strong water channeling action taking place beneath filtering membrane 50 throughout the structure of filter skeleton 43 . The water adhesive effects, strong siphoning action, and ultimate breaking of the water adhesion and resulting continued downward flow of water into an underlying rain gutter accomplished by the filter configuration illustrated in FIG. 6 offers improvements not found in prior art. Referring again to FIGS. 5 & 6, the present invention also exhibits an ability to clean or wash smaller particles out of the 100 micron openings existing between the interconnected threads or wires it employs. This ability has not been noted in prior art but, rather, prior art is known to clog with debris or cake over with pollen, leached shingle oil, dirt, and other pollutants and has not exhibited an ability to self-clean, found in the present invention. The present invention is an improvement over prior art that employs insertable, or under-affixed, or recessed filters such as is employed and illustrated in U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 5,956,904 to Gentry, U.S. Pat. No. 5,619,825 to Leroney, U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 6,134,843 to Tregear and similar prior art because these previous filtration attempts are known to either clog, heal over and become water-proof, and/or channel water forward. Recessed filters beneath a perforated plane such as employed in U.S. Pat. No. 5,595,027 to Vail receive far less water than the present invention due to water adhesion principals that direct water around, rather than through simple perforations. Filtration cloths or membranes resting on top of or sandwiched between screens, perforated planes, or denser filter mediums such as is illustrated in prior art U.S. Pat. No. 4,841,686 to Rees, U.S. Pat. No. 5,595,027 to Vail, U.S. Pat. No. 6,134,843 to Tregear and similar devices are also known to allow water channeling to the front lip of a rain gutter due to the unbroken inter-connected supporting or securing structures beneath or surrounding the filtering membrane and also due to the linear, rather than downward, channeling of water such filtering membranes themselves are known to exhibit in the field. REFERENCE NUMERALS IN DRAWINGS 0 perforations 1 extruded body 2 “scorable” top shelf 3 - 4 - 16 top, side, and bottom planes of 2 nd u-channel 5 vertical leg 13 - 16 v-shaped perforated well 6 vertical leg/“water dam” 12 - 7 - 8 bottom-side and top planes of 1 st u-channel 9 - 10 front “lip” of body 17 - 18 - 26 top, side, and bottom planes of 3 rd u-channel 20 reverse curved plane 22 open channel 19 - 20 rear supporting leg 21 pre-scored indentations 23 pre-scored indentation 24 open channel 25 open channel 28 rain gutter 29 rear u-shaped wall of gutter hangar 27 tensioning/securing flange 30 fastening screw 31 filter material 32 filtration membrane 35 “braked” or formed clip on cover 43 filtration skeletal structure 44 rear ledge of skeletal structure 45 “water drops” of equal length 46 termination of “water drops” 47 ellipses 48 width of perforated plane section 50 filter membrane 51 “water drop” of greater length 52 front ledge of skeletal structure 54 vertical leg 57 forward ledge of skeletal structure

An elongated strip of extruded plastics material includes a vertical rear plane adapted to seat on the rear portion of a gutter-hanging bracket. The rear vertical plane integrally connects to a second forward extending plane that joins, by means of an underlying u-shaped channel, a v-shaped perforated third plane that forces water to pool and drop through the perforations. The third plane joins, by means of an underlying u-shaped channel, a flange that projects outwardly for retaining the strip to a gutter. A filter configuration comprised of a debris repelling membrane, overlying a skeletal structure of ellipsoid rods spaced and resting on vertical planes, serves to break the forward flow of water and to channel water onto and through its integral perforated horizontal plane. The filter configuration is readily inserted into the u-shaped channels existing on the forward and rear edges of the v-shaped perforated third plane.

[0001] This application is a Divisional Application of U.S. patent application Ser. No. 11/443,566, filed May 31, 2006, which claims priority to U.S. Provisional Patent Application No. 60/686,480, filed on Jun. 1, 2005 and incorporated herein by reference. [0002] The United States Government has certain rights in the invention pursuant to Contract No. W-31-109-ENG-38 between the U.S. Department of Energy and the University of Chicago operating Argonne National Laboratory. BACKGROUND OF THE INVENTION [0003] This invention relates to a method of manufacture and alloy composition for preventing metal dusting degradation. More particularly the invention relates to nickel-based alloys with aluminum addition and also to the use of a copper-based layer to prevent metal dusting-corrosion. [0004] Metal dusting is a catastrophic corrosion phenomenon that leads to the deterioration of structural metals and alloys into a dust composed of fine particles of the metal/alloy and carbon. This is usually a localized form of attack and occurs at intermediate temperatures of about 350°-800° C. However, this type of corrosion is possible at any temperature when the carbon activity (a c ) in the gas phase is >>1. Metal dusting corrosion occurs in many metallic alloys, particularly Fe-, Co- and Ni-base alloys, when exposed to carbonaceous atmospheres. Under these conditions, the alloys undergoing metal dusting develop pits and holes on the surface, and then disintegrate into a powdery mixture of carbon, oxides, carbides, and fine metal particles. Metal dusting is a more severe problem than carburization since process equipment or component piping will be functionally inoperative from damage occurring when alloys become fine powder. [0005] Petroleum refineries are one example of industrial environments which need to operate in high carbon activity environments; and as a result, the equipment experiences metal wastage in processes involving hydro-dealkylation and catalyst re-generation systems. Metal wastage also occurs in direct iron-ore reduction plants wherein reformed methane is dried and reheated to enhance ore-reduction efficiency. The ammonia synthesis process also shows metal wastage in the heat-recovery section of the reformed-gas system as well as in the reformer itself. Gases used in heat-treating mixtures contain oil residue on items to form gases that are chemically favorable for metal dusting. Gas mixtures used for carburizing can also cause metal wastage if control of chemistry is not managed. Therefore, the heat-treat industry also suffers metal wastage problem. Other example processes wherein metal wastage occurs are nuclear plants that employ carbon dioxide for cooling the recycle gas loop equipment of coal-gasification units, iron-making blast furnaces in steel mills, and fuel cells that use hydrocarbons. [0006] Metal dusting usually occurs at temperatures as low as 350° to about 800° C. In a hydrogen plant, hot carbon bearing gases are produced primarily by steam reforming and partial oxidation of hydrocarbon at temperatures of 800-1000° C. These gases have to be quenched to 300° C. to avoid metal dusting in the temperature window 400-800° C. Energy in high temperature syngas is not recovered in an efficient manner. Plant production is generally affected by unforeseen shut-downs due to metal wastage problem. Therefore, it is necessary to develop new methods to prevent this metal dusting problem in the temperature window from about 350° to 800° C. [0007] There are conventional techniques to try to reduce metal dusting by coating construction materials with thin layers of copper which are described in US005676821A. The coatings, in general, contain microporosity which can enable the reactive gases to permeate and degrade the integrity of the thin coating layers. It has been shown that carburizing gas can slowly diffuse through the coating layer and eventually lead to failure of the protective coating. This simple coating approach, even though beneficial in short term, is generally not amenable to prevent metal dusting over long term in the service of metallic structures in process plants. [0008] Oxide scales also can play a role in preventing alloys from metal dusting corrosion since carbon diffuses much more slowly through the oxide layers, especially if defects such as pores and cracks are not present in the oxide layers. Because oxide scales are potentially useful in preventing metal dusting corrosion, it is important to consider further the role of their composition and microstructural characteristics in the initiation and propagation of metal dusting. However, the composition and phases present in oxide scales have been rarely investigated and thus not well understood since the oxide layer, generally, is too thin to detect and analyze by conventional X-ray methods. [0009] Copper-aluminum, copper-silicon alloys are also proposed as construction materials to resist metal dusting corrosion (see, for example, WO03072836). However, the mechanical strength of these materials are too low at high temperature for their use as monolithic structural materials for long term service. Many industrial processes involve high pressures and elevated temperatures. Therefore, new approaches are needed to resist metal dusting corrosion of metallic structures for service at high temperatures and high pressures over long term periods of interest in the industrial sector. SUMMARY OF THE INVENTION [0010] While not meant to limit the scope of the invention, it is believed that metal dusting is due to the crystallization of carbon inside the substrate alloys. Carbon diffuses into alloys after it deposits on a surface by catalytic reaction of the gas phase constituents. Carbon then finds a special facet of microcrystal in a metal and precipitates inside the metal, and this process leads to the separation of metal particles. The bulk alloy then finally separates into fine particles and/or metal dust. Whenever carbon diffuses into the alloy, metal dusting is difficult to stop, and an effective way to prevent metal dusting is to build a dense barrier on a surface of metal and minimize carbon diffusion. If carbon cannot diffuse through the barrier, metal dusting corrosion, generally, does not happen. Usually, alloys develop an oxide scale on its surface to prevent metal dusting, and the diffusion rate of carbon in oxide is very low. However, carbon atoms still can diffuse through the defects in oxide scale and reduce the Fe-containing spinel phase to form channels for carbon diffusion. Whenever the channels form, there is no way to stop the diffusion of carbon into alloys. This process leads to initiation and propagation of pitting corrosion. [0011] Copper specimens have been tested in several forms by exposing them in a metal dusting environment at various temperatures. Copper was found to be noncatalytic for carbon deposition. Almost no deposit of carbon was observed in these experiments. The copper was also combined with another metal/metal alloy layer to form a bimetallic barrier layer combination. [0012] The solubility and diffusion rate of carbon in copper are low. Therefore, copper is an excellent material to prevent metal dusting. However, the mechanical strength of copper at high temperature is too low. It is thus difficult to directly use pure copper as a structural material at elevated temperatures. Most of the materials used in metal dusting environment are in the form of vessels, tubing, and piping. Therefore, bimetallic tubing was prepared with an inner copper tubing and an outer Fe or Ni-base alloy tubing to prevent metal dusting corrosion. This dense copper layer on the inside diameter stops the formation/deposit of carbon and also stops the diffusion of carbon, thereby preventing the outer alloy tube from metal dusting corrosion. [0013] The present invention also relates to several Ni-base alloys as materials for use to provide superior resistance to metal dusting degradation when exposed to highly carbonaceous gaseous environments that are prevalent in hydrogen-, methanol-, and ammonia-reformers and in syngas plants. In addition, the alloys developed have adequate strength properties for use as monolithic structural materials in the chemical, petrochemical, and syngas plants at temperatures up to 900° C. The alloys developed have composition ranges (in wt. %) as follows: C 0.02-0.2, Cr 22-29, Al 2.3-3.3, Fe 0-1, Ti 0.3, Zr 0.1-0.2, Y 0-0.1, Balance Ni (all ranges are approximate). The Ti, Zr and C additions are made to control the carbide precipitation and thereby improve the mechanical strength properties at elevated temperatures. Zr and Y additions also contribute to improve the adhesion of the oxide scale to the substrate alloy. The Cr and Al additions in the alloy greatly assist in resisting metal dusting. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 illustrates a schematic drawing of a cross section of a bimetal (Cu/Fe or Ni based alloy) tubing; [0015] FIG. 2A illustrates alloy 800 after exposure in a carburizing gas for 3700 h and [0016] FIG. 2B illustrates alloy 321 after exposure in a carburizing gas for 3700 h; [0017] FIG. 3 illustrates a 3D-profile mapping of corrosion pits in alloy 800 tested in a metal dusting environment at 593° C. for 150 h; [0018] FIG. 4 illustrates an SEM image of Type 321 stainless steel tested in a metal dusting environment at 593° C. for 1100 h; [0019] FIG. 5A illustrates an iron specimen with a 0.8 mm Cu-cladding tested in a metal dusting environment at 593° C. for 600 h, and FIG. 5B illustrates a base iron coupon tested under the same conditions as the specimen of FIG. 5A ; [0020] FIG. 6 illustrates weight change data for copper and iron based alloys after exposure in Gas No. 11 at 593° C. and 1 atmosphere pressure; [0021] FIG. 7 illustrates copper and nickel based alloys exposed to Gas No. 14 at 593° C. at 1 atmosphere pressure; [0022] FIG. 8 illustrates Raman shift versus intensity for a simulated fit of a broad band for Alloy 153MA with Cr 2 O 3 and spinel Raman bands superimposed on the broad band; [0023] FIG. 9 illustrates weight change data for various (Fe, Cr) spinel phases and (Ni, Cr) spinel phase during exposure in a metal dusting gas mixture at 593° C.; [0024] FIG. 10 illustrates X-ray diffraction data for FeCr 2 O 4 and other oxides for Alloy 800 after exposure in a carburizing gas consisting of vol. %: 66.2H 2 -7.1 CO 2 -23 CO-1.4 CH 4 -2.3H 2 O at 593° C. for 1000 h; [0025] FIGS. 11A-11D illustrate Raman data for different Alloys 253MA, 153MA, T91 and T22 after exposure in a carbonizing gas consisting of vol. %: 52H 2 -5.6 CO 2 -18 CO-1.1 CH 4 -23H 2 O at 593° C. for 1000 h; [0026] FIG. 12 illustrates Raman spectra of Alloys 253MA and 601; [0027] FIG. 13 illustrates Raman spectra of Alloys 310 and 602CA; [0028] FIG. 14 illustrates Raman spectra of Alloy 601 exposed in a carburizing gas consisting of vol. %: 53.4H 2 -18.4 CO-5.7 CO 2 -22.5H 2 O at 593° C. at 200 psi for 100 and 2900 h; [0029] FIG. 15 illustrates Raman spectra of Alloy 690 exposed in a carburizing gas consisting of vol. %: 53.4H 2 -18.4 CO-5.7 CO 2 -22.5H 2 O at 593° C. at 200 psi for 100 and 2900 h; [0030] FIG. 16 illustrates Raman spectra of Alloy 45™ exposed in a carburizing gas consisting of vol. %: 53.4H 2 -18.4 CO-5.7 CO 2 -22.5H 2 O at 593° C. at 200 psi for 100 and 2900 h; [0031] FIG. 17 illustrates thermal stability of spinel and Cr 2 O 3 phases in Gas 10 consisting of (in vol %) 53.5H 2 -18.4 CO-5.7 CO 2 -22.5H 2 O. [0032] FIG. 18A illustrates schematically a mechanism for diffusion of carbon and metal dusting of an alloy without presence of Al in the alloy and FIG. 18B with the presence of Al in the alloy; [0033] FIG. 19 illustrates a schematic of a high pressure, high temperature test facility; [0034] FIG. 20A illustrates an SEM micrograph of Alloy 601 after exposure to a metal dusting environment at 14.3 atmosphere and 593° C. for 160 h; FIG. 20B is Alloy 601 at 1 atmosphere and 593° C. for 240 h; FIG. 20C is for Alloy 690 at 14.3 atmosphere and 593° C. for 160 h; FIG. 20D is for Alloy 690 at 1 atmosphere at 593° C. for 240 h; FIG. 20E is for Alloy 617 for 14.3 atmosphere and 593° C. for 160 h; FIG. 20F is alloy 617 at 1 atmosphere and 593° C. is for 240 h; FIG. 20G is for Alloy 214 at 14.3 atmosphere and 593° C. for 160 h; and FIG. 20H is for Alloy 214 at 1 atmosphere and 593° C. for 240 h; [0035] FIG. 21 illustrates weight loss data for several Ni-based alloys (see inset lists of alloys) after exposure in a metal dusting environment at 593° C. and 14.3 atmosphere; [0036] FIG. 22A illustrates an SEM micrograph of Alloy 45™ showing pit size variation after 1540 h; with FIG. 22B after 2180 h; FIG. 22C after 2500 h; and FIG. 22 D after 3300 h; FIG. 22E is for alloy 690 after 2900 h; with FIG. 22F after 4100 h; FIG. 22G after 7300 h and FIG. 22H after 9300 h; FIG. 22I is for alloy 617 after 2900 h; with FIG. J after 4100 h; FIG. 22K after 7300 h and FIG. 22L after 9300 h; [0037] FIGS. 23A-23G illustrate correlation of weight loss and variation in corrosion pit size for a single pit on the surface of the indicated alloy series as a function of exposure time at 593° C. in a metal dusting environment; [0038] FIGS. 24A-24H illustrate 3D-profile mapping of the surface of the indicated Ni-based series of alloys after 9700 h exposure in a metal dusting environment at 593° C. and 14.3 atmospheres; [0039] FIGS. 25A-25H illustrate Raman spectra for the indicated Ni-based series of alloys after 2900 h exposure in a metal dusting environment at 593° C. and 14.3 atmosphere; [0040] FIG. 26 illustrates thermal stability of various indicated spinel and Cr 2 O 3 phases; and [0041] FIG. 27A illustrates Raman spectra of Alloy N06601 after exposure for 100 h and 2900 h for 593° C. in a metal dusting environment at 593° C., FIG. 27B for N07790, FIG. 27C for 617, FIG. 27D for 45™, FIG. 27E for 625; FIG. 27F for 214; FIG. 27G for HR160 and FIG. 27H for 693. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Multi-Layer Metal Tubing [0042] In a first embodiment of the invention a multi-layer metal tubing is illustrated schematically in FIG. 1 at 10 . The most preferred form of the invention constitutes a bi-metal Cu/Fe or Ni based alloy. The thickness of copper and copper alloy tubing is >0.1 mm. It can be preferably bonded or fabricated without bonding between copper inner tubing 12 and outer alloy tubing 14 . Bonding is better because carburizing gas cannot diffuse through between the two tubes in case there is a defect in the copper tubing 12 . To bond the copper tubing 12 together, a thin layer of low melting temperature metals or their mixtures such as zinc, silver, tin, and cadmium, were coated either on outer surface of the copper tubing 12 , or on the inner surface of the alloy tubing 14 , or both surfaces. High temperature and pressure were applied to bond the tubes together. [0043] Experiments were conducted in a horizontal furnace with a quartz tube (2 in dia.) at 1 atm and in a tube furnace at high pressures. The test temperature was 593° C. (1100° F.). The experiments are conducted in several gas mixtures and at several system pressures. Some samples were tested for >10000 h. The composition of test gases used for the evaluation is shown in Table 1. [0000] TABLE 1 Chemical compositions of gas mixture relevant for metal dusting study. H 2 C o C0 2 H 2 0 CH 4 Gas (mol %) (mol %) (mol %) (mol %) (mol %) Other (mol %) 1 43.8 7.2 5.7 39.2 4.1 — 2 52 18 5.6 23 1.1 —  2b 66.2 23 7.1 2.3 1.4 — 3 36.3 8.4 5.6 35 0.2 N 2 15, Ar 0.1 4 74.2 17.5 8.3 0 — — 5 72.2 17.6 8.3 2.0 — — 6 77.2 12.7 10.1 0 — — 7 25.3 70 4 0.01 — — 8 71.4 11.3 17.4 0 — — 9 71 11.7 17.3 0 — — 10  53.4 18.4 5.7 22.5 — — 11  79.5 18.2 — 2.3 — — 12  75.4 6.2 18.4 — — — 13  71.0 2.6 26.4 — — — 14  40 45 5 10 — — 15  20 65 5 10 — — 16  40 25 25 10 — — 17  20 74.5 5 0.5 — — [0044] Table 2 shows that copper and copper alloy specimens were resistant to degradation by metal dusting. However, most of the state-of-the-art, commercial and experimental Fe- and Ni-base alloys were attacked in the same environment. FIGS. 2 and 3 show pits that were observed on surfaces of Alloys 800 and 321 stainless steel after exposure in metal dusting environment. FIG. 4 shows that a deep pit that developed in Alloy 321. In Alloy 800, carbon was heavily deposited on the surface and metal dusting pits were observed, whereas, carbon neither was visually observed on the copper sample, nor was detected by X-ray diffraction. This indicates that copper did not catalyze the gas phase reaction to deposit carbon. Therefore, the carbon growth rate on copper was extremely low. [0045] FIG. 5A shows the surface of the copper-clad iron specimen after exposure to metal dusting environment at 593° C. The surface was clean and devoid of any deposit of carbon. The clad specimen did not lose weight after metal dusting test. However, the surface of the bare (un-clad) iron specimen of FIG. 5B was covered by carbon after metal dusting exposure for only 100 h [0046] iron was consumed at a rate of 0.55-mg/cm 2 -h. The test results indicate that application of a dense copper clad >0.1 mm on the alloy surface prevented metal dusting attack. [0047] FIG. 6 shows a series of metals and metal alloys (alloy key in the inset box). FIG. 6 indicates copper was not attacked by metal dusting even after exposure for >7000 h. However, other Fe-base alloys lost weight significantly during the same exposure period. Copper alloys also showed strong resistance to metal dusting. No weight losses were observed for these alloys after 3000 h exposure to carburizing gas. Meanwhile, Ni-base Alloy 214 severely lost weight (see FIG. 7 ). [0000] TABLE 2 Metal dusting experimental results for Cu alloys Exp. Gas Time Pressure # Material # (h) (atm) Results 33 Cu coated iron and 4 163 1 Clean surface alloys 35 Cu clad Fe plate 4 784 1 Clean surface 36 Glidcop 4 144 1 Clean surface 37 Cu coated iron and 4 120 1 Clean surface alloys 41 Cu 8 100 27 Clean surface 42 Cu 8 100 14 Clears surface 43 Cu 13 100 41 Clean surface 45 Glidcop 4 300 1 Clean surface 49 Cu 10 1131 14 Clean surface 50 Cu 10 100 14 Clean surface 51 Cu 10 113 41 Clean surface 52 Cu 10 680 41 Clean surface 53 Cu 11 8348 1 Clean surface 54 Cu 14 1950 1 Clean surface 56 Cu—Ni-A1 2 14 10027 1 No weight loss 56 Cu—Ni—Al 4 14 10027 1 No weight loss 56 Cu—Ni-AI 12 14 10027 1 No weight loss 56 Cu—Ni-A1 20 14 10027 1 No weight loss 59 Cu—Ni-A1 2 10 8900 14 No weight loss 59 Cu—Ni-A1 4 10 8900 14 No weight loss 60 Cu 10 246 1 Clean surface B.—Nickel-Base Alloys with Low Iron Content [0048] Extensive studies were conducted on metal dusting with a variety of commercial Fe- and Ni-base structural alloys in environments that simulate reformer environment. Alloys generally develop oxide scales in the exposure environment, but depending on the phases present in the oxide scales in the reduction of these phases, lead to nucleation and growth of pits leading to catastrophic failure of the alloy into powder. The characteristics of different oxide scales were examined and also correlated the information with the compositions of the alloys and their resistance to metal dusting. [0049] It was determined that diffusion of carbon through oxide scale is difficult. However, Fe-, Co, and Ni-base alloys cannot avoid metal dusting corrosion if high activity carbon diffuses into the alloys. Therefore, the quality of the oxide scale is very important for alloys to resist metal dusting corrosion. Raman experiments show there are three types of oxides in oxide scale, which are Cr 2 O 3 , disordered chromium oxide, and Fe 1+x Cr 2−x O 4 (0≦x≦1) spinel ( FIG. 8 ). [0050] To study the reaction of these oxides with carburizing gas, Cr 2 O 3 , (Fe, Cr) 3 O 4 spinel, and Cr metal were tested in a carburizing gas consisting of (in vol. %) 52H 2 -5.6 CO 2 -18CO 1.1 CH 4 -23H 2 O at 593° C. in a thermo gravimetric test apparatus. Disordered chromium oxide and Cr 2 O 3 formed on the surface of Cr metal. Weight gains of FeCr 2 O 4 , Cr 2 O 3 , and Cr metal were almost zero. Although the carbon activity of the carburizing gas consisting of (in vol. %) 52H 2 -5.6CO 2 -18CO 1.1 CH 4 -23H 2 O was >1 at 593° C., the deposition of carbon on Cr 2 O 3 , disordered chromium oxide, and FeCr 2 O 4 is difficult since the activation barrier is high for the following reactions: [0000] CO+H 2 ═C+H 2 O  (1) [0000] 2CO═C+CO 2   (2) [0051] If the alloy surface is totally covered by Cr 2 O 3 , disordered chromium oxide, and FeCr 2 O 4 , carbon deposition and metal dusting may not occur. However, weight gain was observed for Fe 1.8 Cr 1.2 O 4 , and the carbon deposition rate in Fe 2.4 Cr 0.6 O 4 was much larger than that of Fe 1.8 Cr 1.2 O 4 ( FIG. 9 ). Therefore, spinel with high iron content seems to catalyze reaction 1 and/or 2 , which leads to deposition of carbon. [0052] Cr 2 O 3 is stable in carbon and hydrogen atmospheres down to very low PO 2 . This oxide is an excellent protective layer in preventing alloys from metal dusting corrosion. Fe(Cr 1−x Fe x ) 2 O 4 spine, on the other hand, is not as stable as Cr 2 O 3 . The composition of the spinal can vary from FeCr 2 O 4 [x=0 in Fe(Cr 1−x Fe x ) 2 O 4 ] to Fe 3 O 4 (x=1). As mentioned above, Fe 3 O 4 is not stable when the H 2 O concentration is low. The stability of FeCr 2 O 4 is higher than that of Fe 3 O 4 , but lower than that of Cr 2 O 3 . If there are no defects such as nonuniform distribution of cations, FeCr 2 O 4 should be stable in a carburizing gas. However, it has been reported that FeCr 2 O 4 starts to be partially reduced by carbon at 600° C. FIG. 10 shows that the X-ray peak position of the spinal on the surface of Alloy 800 is between Fe 3 O 4 and FeCr 2 O 4 , and the peak is also much broader than that of polycrystalline Fe 3 O 4 and FeCr 2 O 4 . Thus, it appears the spinal on the surface of alloy is not stoichiometric FeCr 2 O 4 , but has higher iron content and such a spine is likely susceptible to reduction by carbon. [0053] The higher the concentration of iron in Fe(Cr 1−x Fe x ) 2 O 4 , the easier is the spinel reduction. The ratio of Fe/Cr in spinel may vary with oxygen partial pressure in gas. When PO 2 in gas, such as in Gas 1, is higher than 7×10 −26 atm, the most unstable spinel Fe 3 O 4 could form, which could be attacked by carbon leading to metal dusting corrosion of the underlying alloy. It is difficult to measure the iron content in the oxide layer because it is too thin. However, the iron content in the oxide scale increases with increasing iron content in the alloy. Furthermore, the iron concentration may not be uniform in the oxide scale. Some spots with high iron content may react with carbon first and metal dusting will start from those regions. FIG. 11B shows that alloy 153MA has less spinel phase in the oxide scale than does T91; therefore, 153MA has fewer defects susceptible to attack by metal dusting corrosion than does alloy T91 of FIG. 11C . This is also consistent with the observation of smaller mass loss for 153MA than that for T91. [0054] FIGS. 12 and 13 show the differences in Raman spectra for two pairs of alloys: Alloy 253MA and 601, and Alloy 310 and 602CA. These alloys were exposed for 1000 h to Gas 10 at 593° C. and 200 psi. The Cr content in Alloy 253MA (20.9%) and 601 (21.9%) is similar. However, the Fe-base alloy 253MA has a much stronger spinel peak than that of the Ni-base alloy 601 ( FIG. 12 ). Pits were observed on Alloy 253MA, but not on Alloy 601 when exposed under the same experimental conditions. The Cr content in Alloy 310 (25.5%) and 602CA (25.1%) is also similar. FIG. 13 shows the strong spinel peak for the Fe-base Alloy 310, but almost no such peak for the Ni-base Alloy 602CA. Pits were again observed only on Alloy 310, but not on Alloy 602CA. Less spinel in the oxide scale of Ni-base alloys only means that the development of spinal takes a much longer time and that the incubation time for metal dusting initiation is much longer. However, the presence of Fe, even in low concentration, in Ni-base alloys will lead to metal dusting degradation during years of service planned for these structural components in reformer environments. [0055] Phase composition of oxide scales that developed on surface of alloys changes with exposure time. FIGS. 14 to 16 (601, 690, 45™) show the intensity differences of Raman bands for Cr 2 O 3 and spinel phases in oxide scale on surfaces of several alloys. When the alloys were exposed for only 100 h, Cr 2 O 3 was the major phase in oxide scales that developed on surface of alloys. However, after 2900 h exposure, the intensity of spinel band in Raman spectra increased significantly. [0056] The increasing amount of spinel phase in oxide scales over longer exposure time can be attributed to the outward diffusion of Fe from the alloy substrate. At early stages, Cr-rich oxide forms on the surface of alloys. However, as the outward transported Fe is incorporated into the scale, spinel phase becomes dominant as was observed in the Raman spectra. The diffusion rate of Fe and its incorporation in the scale to form the spinel phase would have a pronounced effect on the incubation time for the onset of metal dusting in the alloy. As the transported Fe is incorporated into the spinel phase, the protective capacity of the spinel is reduced, since the inward migrating carbon can easily reduce the high-iron-containing spinel (as discussed earlier). [0057] Raman spectra showed that the intensity of Cr 2 O 3 band at ≈560 cm −1 was low for Alloy 45™ and the relative intensity of spinel is high. As was discussed earlier, spinal phase in the scale is not as good as Cr 2 O 3 scale in preventing alloys from metal dusting corrosion, which probably is the cause for the alloy to undergo metal dusting. The Cr content in 45™ is relatively high but the Fe content is also high. The presence of high Fe content may stabilize the Fe-containing spinal phase rather than Cr 2 O 3 , thereby subjecting the alloy to metal dust. NiCr 2 O 4 spine is not thermodynamically stable in a reducing environment used in our study and therefore, could not form at 593° C. (see FIG. 17 ). The results suggest that an alloy with a high Cr content (with or without Al) and almost no Fe content may stabilize Cr 2 O 3 and/or a spinal phase with high Cr content, thereby prolong the incubation period for the onset of metal dusting and subsequent propagation of the process leading to metal wastage. Even small addition of iron will affect the quality of oxide scale and decrease the ability of alloys to resist metal dusting. [0058] FIGS. 18A and 18B are schematic representations of a non-limiting mechanism that explains the function of aluminum in the resistance of alloys to metal dusting corrosion. Physical defects may be present in oxide scales that develop on the surface of alloys. When carbon deposits on these surfaces during exposure to a metal dusting environment, carbon diffuses through these defects and reduces the spinel phase to Fe 3 C and/or Ni metal. These particles form channels for transferring carbon through the oxide scale. Oxygen may also diffuse through these channels leading to the formation of additional Cr oxide and slowing the diffusion of carbon. However, the carbon diffusion rate is probably higher than that of oxygen and formation of additional Cr oxide beneath the carbon channel may not be feasible. Therefore, carbon can continue to diffuse into alloys through the channels and finally form metal dusting pits. When Al is added to the alloy, alumina scale usually forms under the Cr oxide scale. The alumina may affect resistance to metal dusting corrosion in two ways. First, the carbon transferred through the channel may not be able to penetrate through the alumina layer because alumina is much more stable than spinel. Second, the partial pressure of oxygen needed to form Al 2 O 3 (3.6×10 −57 atm) is much lower than that needed to form Cr 2 O 3 (2.6×10 −37 atm) at 593° C. A thin layer of alumina scale can form (even with limited oxygen transport through the channel) beneath the carbon diffusion channel, and thereby reduce the growth of metal dusting pits. [0059] Various non-limiting examples are provided hereinafter and are based on the following experimental procedure: EXAMPLES [0060] The test program included eight Ni-base wrought alloys, predominantly those which are commercially available. Table 3 lists the nominal chemical compositions of the alloys. The alloys had complex chemical compositions and contained Cr (in a range of 15.4-28 wt. %) and several other elements, such as Mo [alloy 617 (UNS N06617)], Al [601 (UNS N06601), 617 (UNS N06617), 602CA (UNS N06025), 214 (UNS N07214), and 693 (UNS N06693)], and Si [45™ (UNS N06045) and HR 160 (UNS N12160)]. Alloy 690 (UNS N06690) containing 27.2 wt. % Cr, but without additions of Si, or Mo, or Al was also included in the study. Further, several alloys contained Nb, W, and Co, which can also influence the oxidation behavior of the alloys and their resistance to metal dusting attack. [0000] TABLE 3 Nominal composition (in wt. %) of alloys selected for the study. Alloy UNS. C Cr Ni Mn Si Mo Al Fe Other N06601 0.03 21.9 61.8 0.2 0.2 0.1 1.4 14.5 Ti 0.3, Nb 0.1 N06690 0.01 27.2 61.4 0.2 0.1 0.1 0.2 10.2 Ti 0.3 N06617 0.08 21.6 53.6 0.1 0.1 9.5 1.2 0.9 Co 12.5, Ti 0.3 N06025 0.19 25.1 62.6 0.1 0.1 — 2.3 9.3 Ti 0.13, Zr 0.19, Y 0.1 N07214 0.04 15.9 Bal 0.2 0.1 0.5 3.7 2.5 Zr 0.01, Y 0.006 N06045 0.08 27.4 46.4 0.4 2.7 — — 26.7 RE 0.07 N12160 0.05 28.0 Bal 0.5 2.8 0.1 0.2 4.0 Co 30.0 N06693 0.02 28.8 Bal 0.2 — 0.1 3.3 5.8 Nb 0.7, Ti 0.4, Zr 0.03 [0061] The samples were flat coupons with approximate dimensions of 12×20×1 to 2 mm. They were sheared slightly oversize, and their edges were milled to remove cut edges and reduce the coupons to final size. A standard surface finish was used for all alloy specimens. The finish involved a final wet grinding with 400-grit SiC paper. Stenciling or electric engraving at the corner of the coupons identified all of the specimens. Prior to testing, specimens were thoroughly degreased in clean acetone, rinsed in water, and dried. The specimen dimensions were measured to +0.02 mm, and the total exposed surface area, including edges, was calculated. The specimens were weighed to an accuracy of 0.1 mg. [0062] FIG. 19 shows a schematic of a system that was used to conduct experiments at system pressures up to 600 psi. The system consisted of a horizontal, tubular, high temperature furnace capable of operation up to 900° C. The reaction chamber, with gas inlet/outlet fittings, fabricated from alumina and/or quartz was positioned within a pressure vessel made of a high temperature heat-resistant alloy (16-mm ID, 50-mm OD, 500-mm long). A chromel-alumel thermocouple was inserted into the pressure vessel to monitor the specimen temperature. Specimens were suspended from a quartz specimen holder and were positioned in the constant-temperature section of the tubular furnace. High-purity gases such as CO, CO 2 , and H 2 , were piped into the reaction chamber through flow meters to obtain the desired composition. To include steam in the exposure environment, water was pumped from a water pump, converted to steam, pressurized, and inserted along with the gas mixture. The effluent from the reactor chamber was condensed to remove the water prior to exhaust. Specimens were exposed to a flowing gas consisting of 53.4% H 2 -5.7% CO 2 -18.4% CO-22.5% H 2 O at 593° C. and 14.3 atm. The gas is a simulation of a reformer outlet gas. The calculated carbon activity of the gas at 593° C. is 2.2, 31, and 89 at 1, 14.3 and 40.8 atm, respectively, based on the reaction CO+H 2 ═C+H 2 O. [0063] Several analytical approaches and techniques were used to evaluate the tested specimens. These included metal weight gain/loss in as-exposed and cleaned conditions, pitting size and density (pits per unit area of surface), pit depth (average depth over significant number of pits), and substrate penetration as determined by metallographic examination. After the specimens were weighed in the as-exposed condition, deposits on the specimens were mechanically removed with a soft brush, and the deposit material was analyzed for metal content, if warranted. The brushed specimens were cleaned ultrasonically to remove residual deposits and then washed in water and dried. Subsequently, the specimens were weighed, and the weight gain/loss was noted. The cleaned specimens were examined for surface pits by optical microscopy. This allowed determination of the number of pits present in different regions of the specimen and the pit density. In addition, the sizes of several pits were measured and averaged to establish an average pit size. [0064] At the end of a given run, several of the cleaned specimens (after weighing and pit measurement) were cut and mounted on the cut faces for metallographic polishing and examination in as-polished and in electrolytically etched (with a 10% acetic acid solution at 10 V for 30 sec) conditions, by optical and/or scanning electron microscopy. Pit depth and substrate penetration thickness were measured in several exposed specimens. Raman spectra were excited with 60 mW of 476-nm radiation from a Kr-ion laser. The incident beam impinged on the sample at an angle=45° from the normal. Scattered radiation was collected along the surface normal with an NA lens and was analyzed with a triple Jobin-Yvon grating spectrometer. All of the spectra were acquired in 300 sec at room temperature. [0065] Ni-base alloys possess better resistance against metal dusting attack than the Fe-base alloys. Without limiting the invention, the difference in the lattice mismatch in catalytic crystallization of carbon may be one reason. The misfit between Ni lattice to graphite lattice (3.6%) is much higher than that between Fe 3 C and graphite (0.28%). Lattice of Fe 3 C almost perfectly matches the lattice of graphite. This indicates that carbon atoms moving from lattice of Fe 3 C to graphite is easier than that from Ni to graphite. Therefore, the precipitation of carbon on surface of Ni has a higher energy barrier than that on surface of Fe 3 C, which leads to lower carbon precipitation rate, smaller crystallite size, and lower metal dusting rate. The observed crystallite size of coke on nickel was smaller than that on iron. This difference suggests that Fe 3 C is better than Ni in serving as a template for the catalytic crystallization of carbon, and may explain why the metal dusting rate of Fe and Fe-base alloys is higher than that of Ni and Ni-base alloys. The other factor that can affect metal dusting rate is the chemical and mechanical integrity of the oxide layer that develops on the surface of alloys. In this set of examples, the effect of alloy chemistry and phase composition of oxides on surface of Ni-base alloys on metal dusting rates shown. The information on metal dusting rate of several Ni-base alloys was examined in order to establish the best candidate alloys to resist metal dusting corrosion. Weight Loss and Pit Development [0066] No metal dusting attack was observed for Ni-base alloys in relatively short exposure time of 246 h at 1 atm pressure (Table 4). However, pits were observed on Alloys N06601, N06690, N06617, and N07214 when exposed in the same gas at 593° C. and 14.3 atm (see Table 2). Similar results were obtained when specimens were tested at 40.8 atm (Table 4). FIGS. 20A to 20H show the surface of several indicated alloys after exposure at 593° C. and 1 and 14.3 atm. The carbon activity in the gas is 14 times higher than at 1 atm, which can decrease the incubation time for the initiation of metal dusting pits the alloy surface. [0000] TABLE 4 UNS number of Surface characteristics after exposure at alloy 1 atm 14.3 atm 40.8 atm N06601 Clean surface Pits Pits N06690 Clean surface Pits Pits N06617 Clean surface Pits Pits N06025 Clean surface Clean surface Clean surface N07214 Clean surface Pits Pits N06045 Clean surface Clean surface Clean surface N12160 Clean surface Clean surface Clean surface [0067] Metal dusting attack, as measured by weight loss, was observed on all the Ni-base alloys when tested for 9700 h in the same gas environment at 593° C. and 14.3 atm (see FIG. 21 ). However, the weight loss rates for Alloys N06693 and N06045 were very low. Both alloys contain Al, have high Cr content, and low amount of Fe. The weight loss rate for Alloy N06045 was the highest among the Ni-base alloys used in the study, although the Cr content in this alloy is fairly high. The iron content in Alloy N06045 is also the highest among these alloys. The weight loss rate of Alloy N06601 was also high. The iron content in Alloy N06601 is the second highest among these alloys. The results indicate that addition of iron to the Ni-base alloys results in substantial decrease in incubation time for the onset of metal dusting. When Fe content in the alloy >10 wt. %, the alloy is readily attacked as evidenced by numerous pits on the exposed surfaces of the alloy specimens. The weight loss rate for cobalt-containing Alloy N06617 is the second highest among these alloys. Mo addition in this alloy did not improve its resistance to metal dusting corrosion. The other cobalt-containing Alloy N12160 also exhibited metal dusting degradation, although it contained 28% Cr. Therefore, Co addition in alloys is also not beneficial in resisting metal dusting. The Cr content in Alloy N07214 is the lowest among these alloys and its weight loss rate was also high although it contained aluminum. High Cr content in alloys seems essential but not entirely sufficient for preventing metal dusting corrosion in Ni-base alloys. [0068] Even though weight loss data developed for various alloys are useful in evaluation and ranking of the alloys from their susceptibility to metal dusting attack, such data may indicate the protective capacity of the surface oxide scale and probably represent only an average behavior for the alloy in a given exposure environment and temperature. Since the corrosion damage in the alloy occurs by nucleation of pits on the surface and their growth inward, it is essential to develop an understanding of the morphology of pits (such as pit size, pit distribution, pit depth, etc.) on the alloy surface and of the maximum growth rate of the pits to evaluate the ultimate damage of component failure under a given set of exposure (process) conditions. [0069] During the course of the 9700 h exposure experiment, the specimens were retrieved periodically and SEM photomicrographs taken of different regions all the specimens to characterize and monitor their growth as a function of exposure time. FIGS. 22A-22C show the SEM photomicrographs of pit development in alloys N06045, N06690, and N06617 after exposure for different times in the metal dusting environment at 593° C. and 14.3 atm. [0070] The dimension of a single pit (for each alloy) was measured as a function of exposure time and correlated the pit size data with measured weight change for the corresponding alloys. Table 5 lists the maximum pit size and weight loss for various alloys. FIGS. 23A-23G show the measured pit size and weight change for all the alloys used in the present study. The plots, for most of the alloys, indicate a good correlation between the growths in the size of an arbitrarily selected pit on the surface of the alloy with the measured weight change. Furthermore, absolute increase in pit size as a function of exposure time is different for different alloys. For example, the pit size increases from 200 to 450 μm as the exposure time increases from 4000 to 9300 h for Alloy N06601. The corresponding increases for Alloy N06690 are 70 to 200 μm for time increase of 2900 to 9300 h. Similar information for other alloys can be obtained from the curved shown in FIGS. 23A-24G . [0000] TABLE 5 Maximum pit size and weight loss for alloys after 9,700-h exposure. UNS number Weight loss Pit depth Pit diameter Ratio of pit depth of alloy (mg/cm 2 ) (μm) (μm) to pit diameter N06601 19.5 110 450 0.244 N06690 6.5 147 440 0.334 N06617 35.1 201 887 0.227 N06025 2.1 96 374 0.256 N07214 25.6 Uniformly corroded N06045 1 59.1 141 600 0.235 N12160 7.3 13 210 0.062 N06693 0.1 37  99 0.374 1 The alloy was exposed only for 3,300 h whereas the others were exposed for 9,700 h. [0071] The behavior of alloy N07214 is somewhat different from that of others, since there is a poor correlation between the size increase of a single pit in this alloy with its weight change. The reason for this poor correlation is because this alloy contains low (15.9 wt. %) concentration of Cr and a high (3.7 wt. %) concentration of Al and develops a large number of small pits. The nucleation and growth of a large number of small pits with low growth rates reflects in the weight change but on the growth rate of an individual pit. The alloy exhibited a uniform coverage after 3000 h exposure and the size of an individual pit could not be measured. Alloy N06045 exhibited an extremely rapid growth rate for the pit (380 to 600 μm during 1400 to 3400 h) and its exposure was terminated after 3800 h. The cause for the rapid increase in pit growth in this alloy can be attributed to higher (26.7 wt. %) Fe content of the alloy. FIGS. 24A-24H show a comparison of SEM photomicrographs of surfaces of several alloys after exposure at 9700 h at 593° C. to the metal dusting environment. It is evident from this figure that Alloy N07214 develops a rough surface, attributed to multitude of small and probably shallow pits. Phase Composition of Scales [0072] Raman spectra were excited with 60 mW of 476-nm radiation from a Kr-ion laser. The scattered light was analyzed with a triple Jobin-Yvon grating spectrometer. All of our spectra were acquired in 300 sec at room temperature. Raman spectra were developed on alloys after exposure at 100 and 2900 h. FIGS. 25A-25H shows a comparison of Raman spectra obtained on the indicated alloys after exposure at 2900 h to the metal dusting environment. [0073] Raman spectra showed that the intensity of Cr 2 O 3 band at about 560 cm −1 was low for both Alloys N07214 and N06045 and the relative intensity of spinel is high in both the alloys. Spinel phase in the scale is not as good as Cr 2 O 3 scale in preventing alloys from metal dusting corrosion, which probably is the cause for these two alloys to undergo metal dusting. The low Cr 2 O 3 content on surface of Alloy N07214 may be due to the low Cr content in alloy. On the contrary, Cr content in N06045 is relatively high but the Fe content is also high. The presence of high Fe content may stabilize the Fe-containing spinel phase rather than Cr 2 O 3 , thereby subjecting the alloy to metal dust. The fit to the broad Raman band for alloy N06045 is due to disordered chromium oxide with oxygen vacancies. NiCr 2 O 4 spinel is not thermodynamically stable in a reducing environment used in our study and therefore, could not form at 593° C. ( FIG. 26 ). The results suggest that an alloy with a high Cr content (with or without Al) and low Fe content may stabilize Cr 2 O 3 and/or a spinel phase with high Cr content, thereby prolong the incubation period for, the onset of metal dusting and subsequent propagation of the process leading to metal wastage. [0074] Phase composition of oxide scales that developed on surface of alloys changed with exposure time. FIGS. 27A-27H show the intensity differences of Raman bands for Cr 2 O 3 and spinel phases in oxide scale on surfaces of several alloys after 100 and 2900 h exposure. When the alloys were exposed for only 100 h, Cr 2 O 3 was the major phase in oxide scales that developed on surface of alloys. However, after 2900 h exposure, the intensity of spinel band in Raman spectra increased significantly. On Alloy N07214, spinel became the major phase after exposure for 2900 h, whereas Cr 2 O 3 was the major phase in the oxide scale when the alloy had been exposed for 100 h. [0075] The increasing amount of spinel phase in oxide scales over longer exposure time can be attributed to the outward diffusion of Fe from the alloy substrate. At early stages, Cr-rich oxide forms on the surface of alloys. However, as the outward transported Fe gets incorporated into the scale, spinel phase becomes dominant as was observed in the Raman spectra. The diffusion rate of Fe and its incorporation in the scale to form the spinel phase would have a pronounced effect on the incubation time for the onset of metal dusting in the alloy. As the transported Fe gets incorporated into the spinel phase, the protective capacity of the spinel is reduced, since the inward migrating carbon can easily reduce the high-iron containing spinel. [0076] The Raman analysis showed that the spinel band intensity was the lowest for Alloy N06693 after 2900 h exposure in the environment used in the study at 593° C. and 14.3 atm, indicating that the incubation time for the onset of metal dusting for this alloy will be significantly greater than most of the others studied in this program. [0077] In accordance with the principals of the present invention, a non-limiting model explains the function of aluminum to resist metal dusting corrosion as shown in ( FIGS. 18A and 18B ) as discussed hereinbefore. There may be defects in oxide scale that develop on surface of alloys. When carbon deposits on surface of alloys during exposure to metal dusting environment, carbon diffuses through these defects and reduce the spinel phase to Fe 3 C and/or Ni metal. These particles form channels for transferring carbon through oxide scale. Oxygen may also diffuse through the channels resulting in formation of additional chromium oxide. However, the carbon diffusion rate is probably higher than that of oxygen and formation of additional chromium oxide beneath the carbon channel may not be feasible. Therefore, carbon can continue to diffuse into alloys through the channels and finally form dusting pits. When aluminum is added to the alloy, alumina scale usually forms underneath chromium oxide scale. There may be two effects of alumina to resist metal dusting corrosion. First, the carbon transferred through the channel may not be able to penetrate through alumina layer because alumina is much more stable than spinel. Second, the partial pressure of oxygen to form Al 2 O 3 (3.6×10 −57 atm) is much lower than that of Cr 2 O 3 (2.6×10 −37 atm) at 593° C. A thin layer of alumina scale can form (even with limited oxygen transport through the channel) beneath the carbon diffusion channel, thereby reducing the growth of metal dusting pits. [0078] It should be understood that various changes and modifications referred to in the embodiment described herein would be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention.

An article of manufacture for reducing susceptibility of a metal pipe to metal dusting degradation. The article includes a multi-layer tubing having an alloy layer and a copper layer. The alloy layer can include a Ni based, an Al based and an Fe based alloy layer. In addition, layers of chrome oxide, spinel and aluminum oxide can be used.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims priority under 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 60/358,157, filed Feb. 20, 2002, entitled “Novel Materials for Dental and Biomedical Application.” The application is incorporated herein by this reference. STATEMENT AS TO INVENTION RIGHTS UNDER FEDERALLY SPONSORED RESEARCH [0002] This work was supported by NICDR research grants DE12350 and DE13414. The United States government may have certain rights in the inventions disclosed herein. BACKGROUND [0003] Biological implants, such as joint and dental prostheses, usually must be permanently affixed or anchored within bone. In some instances it is acceptable to use a bone cement to affix the prosthesis within bone. In the case of many joint prostheses, however, it is now more common to affix the joint prosthesis by encouraging natural bone growth in and around the prosthesis. Bone-to-implant interfaces that result from natural bone ingrowth tend to be stronger over time and more permanent than are bone cement-prosthesis bonds. [0004] Optimal bone ingrowth requires that natural bone grow into and around the prosthesis to be implanted. Bone ingrowth and bone or dental prosthesis fixation can be enhanced by providing irregular beaded or porous surfaces on the implant. Although various materials, including titanium alloys, are biocompatible, they are not necessarily bioactive because they can neither conduct bone formation nor form chemical bonds with bone. Thus, enhanced fixation of implants within bone can be attained by coating the implant with a bioactive mineralized and/or ceramic material. Such coatings have been shown to encourage more rapid bone ingrowth in and around the prosthesis. [0005] Calcium phosphate ceramics, especially hydroxyapatite, have been shown to conduct bone formation. Hydroxyapatite ceramic has been successfully applied as a coating on cementless metallic implants to achieve quick and strong fixation. Thermal plasma spraying is one of the more common methods used to produce hydroxyapatite coatings. However, the resulting plasma-sprayed hydroxyapatite coating is of relatively low density and is not uniform in structure or composition. The adhesion between the coating and substrate is generally not very strong, especially after long term exposure within the body. The generation of hard ceramic particles, resulting from the degradation of thermal plasma sprayed coating, and coating delamination, are major concerns. Also, implants or other polymers with porous structures or complex surfaces are difficult to coat uniformly using line-of-sight temperature plasma spraying. [0006] A general overview of orthopedic implantable materials is given in Damien, Christopher J., and Parsons, Russell J., 1991, Journal of Applied Biomaterials, v2, 187-208. Information related to attempts to address these problems can be found, e.g., in U.S. Pat. Nos. 6,139,585; 6,051,272; 5,609,633; and in some of the publications disclosed herein. Each of these references suffers from one or more of the following disadvantages: weakness, brittleness or unevenness of coatings, a lack of chondrogenic or osteogenic activities, inability to promote the regeneration of periodontal tissues, and the problem of contamination with components which may cause severe immunological reactions. [0007] Thus, a need exists for the production of improved enamel inspired materials which are appropriate for biomedical and dental applications and which overcome the problems discussed above. SUMMARY [0008] The invention provides an improved method for synthesizing coated implantable articles suitable for biomedical and dental applications. In one embodiment, the method generally comprises the step of contacting an implantable substrate to be coated with a supersaturated calcifying solution, where the solution comprises an effective amount of an amelogenin-type protein. Typically, the substrate will be immersed in the solution under suitable temperature conditions until the desired amount of an enamel-like biomaterial coats the substrate surface. The surface may be coated partially or entirely with the enamel-like biomaterial, depending on the user's preference. Where the coating appears, it is chemically bonded to the surface of the substrate. [0009] The method may be applied to a variety of substrates, including metals, ceramics, polymers and silicon. In particular, the method is useful for coating substrates which are intended for medical implantation, such as bone and dental prostheses. In one embodiment, the substrate may be composed of a strong biocompatible material, for example, a metal such as titanium. In other embodiments, metals including titanium alloy, tantalum, tantalum alloy, stainless steel or cobalt chromium alloy are coated. Other embodiments of the method use well-known biocompatible materials such as ultra high molecular weight polyethylene, hydroxyapatite, Bioglass and Glass Ceramic A-W. [0010] Another embodiment of the invention includes a step in which the metal substrate is activated for crystal growth by a nanometer-scaled porous oxide layer at the metal's surface. One means of achieving such activation is by etching. Many methods of etching are known to those skilled in the art. One useful etching method comprises the steps of contacting the substrate with an effective amount of acid and an effective amount of an oxidizing agent. [0011] In one embodiment of the method of the invention, the substrate to be coated is contacted with a supersaturated calcifying solution comprising calcium phosphate and a buffer which maintains an approximately neutral pH. Typically, the coating reaction is carried out at any temperature between approximately ambient room temperature and a biologically relevant temperature such as the temperature of the human body (i.e., 37 degrees Celsius). [0012] The ionic strength of the supersaturated calcifying solution is between approximately 50 mM and 500 mM. In one embodiment, the ionic strength is between 100 and 200 mM. [0013] In another embodiment, the amelogenin-type protein dissolved in the supersaturated calcifying solution has a function similar to that of mouse amelogenin rM179. In a related embodiment, the amelogenin-type protein comprises the sequence shown in SEQ ID No. 1. The amelogenin-type protein is typically present at concentrations greater than approximately 12.5 μg/ml, including concentrations of 100 μg/ml, or higher. [0014] In other embodiments of the method, the substrate to be coated is exposed to the calcifying solution for approximately an hour or more. The substrate may be exposed to the solution for 24 hours or longer, depending on the thickness or extent of substrate coating desired. [0015] In certain embodiments of the coating method, additional steps are added. For example, in one embodiment, before contacting the substrate with the calcifying solution containing the amelogenin-type protein, the substrate is first contacted with a supersaturated calcifying solution which is substantially free of any amelogenin-type protein. [0016] A further object of the invention is to provide a coating method wherein agents in addition to the amelogenin-type protein are included in the calcifying solution or solutions to which the substrate is exposed. For example, in some embodiments, therapeutic agents such as antibiotics, growth factors, or anti-inflammatory agents are added to the calcifying solution and incorporated into the enamel-like coating. [0017] The amelogenin-type protein of the invention may be incorporated into the enamel-like coating at varying levels depending on parameters such as the concentration of the amelogenin-type protein in the calcifying solution. In some embodiments, the enamel-like coating comprises between 1×10 −3 % and 1% w/v amelogenin-type protein, although the amounts may vary, for example, to encompass the range from 1×10 −4 % and 10% w/v amelogenin-type protein. [0018] Another object of the invention is to provide a method for coating an implantable substrate with an enamel-like biomaterial which comprises submicron bundles of elongated apatite crystals with an average aspect ratio (length/width) of at least two. [0019] Yet another object of the invention is to provide a method for modifying the growth of apatite crystals on an implantable substrate. According to one embodiment of this method, crystal growth modification is achieved by the addition of an effective concentration of an amelogenin-type protein to a supersaturated calcifying solution. The substrate on which crystals are grown is then be contacted with the calcifying solution under suitable conditions until the desired growth of crystals is achieved. Typically, the growth of apatite crystals will be modified to produce submicron-sized crystals with an average aspect ratio of approximately two or greater. [0020] This invention also provides the articles produced by the methods described herein. [0021] A further object of the invention is to provide an implantable article which comprises a biocompatible substrate coated with an enamel-like biomaterial. In one variation of this embodiment of the invention, the enamel-like surface coating is chemically bonded to at least a portion of the substrate and comprises apatite crystals and an amelogenin-type protein. In a related embodiment, the crystals are less than 1 μm in length with an average aspect ratio (length to width) of approximately two or greater. In various other embodiments, the crystals which comprise the substrate coating contain carbonate or magnesium in addition to calcium and phosphate, and the calcifying solutions comprise magnesium, sodium, sulfate, chlorine, carbonate or silicate ions, or mixtures thereof. [0022] In a related embodiment, the enamel-like coating of the invention comprises, in addition to amelogenin-type proteins, a therapeutic agent or agents. Such agents include, but are not limited to, growth factors such as, bFGF, aFGF, EGF (epidermal growth factor), PDGF (platelet-derived growth factor), IGF (insulin-like growth factor), TGF-.beta. 1 through 3, including the TGF-.beta. superfamily (BMP's, GDF-5, ADMP-1 and dpp); cytokines, such as various interferons, including interferon-alpha, -beta and -gamma, and interleukin-2 and -3; hormones, such as insulin, growth hormone-releasing factor and calcitonin; non-peptide hormones; antibiotics; anti-cancer agents and chemical agents, such as chemical mimetics of growth factors or growth factor receptors. In certain embodiments, the therapeutic agents include those factors, proteinaceous or otherwise, which are found to play a role in the induction or conduction of growth of bone, ligaments, cartilage or other tissues associated with bone or joints, such as for example, BMP and bFGF. [0023] Yet another object of the invention is to provide a method of enhancing bone ingrowth or soft tissue attachment by implanting an article coated with the enamel-like biomaterial of the invention onto a bone surface or soft tissue. In a related embodiment, the invention provides a method for delivering a therapeutic agent comprising implanting the an article coated with the enamel-like biomaterial of the invention, and further comprising a therapeutic agent, onto a bone surface or soft tissue. [0024] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings. DESCRIPTION OF THE DRAWINGS [0025] FIG. 1 shows SEM micrographs of titanium surfaces: (a) untreated, (b) HF etching, (c) HF etching and NaOH immersion. Arrows point to nano-sized-structures in (b) and nano-sized-pores in (c). [0026] FIG. 2 shows XRD (X-ray diffraction) patterns of Ca—P formed on chemically modified titanium via Process I (a-c) at: (a) no protein, (b) 100 μg/ml rM 179 and (c) 100 μg/ml BSA and Process II (d-f) at: (d) no protein, (e) 100 μg/ml BSA and (f) 100 μg/ml rM 179. The patterns (g) and (h) were from samples after 4 h of SCS1 immersion and from chemically modified titanium, respectively. The diffraction peaks were assigned according to the standard JCPDS cards (1980, JCPDS International Center for Diffraction Data. Powder Diffraction File. Swarthmore, Pa.). [0027] FIG. 3 shows SEM micrographs of the cross section (a) of the Ca—P coating formed on the chemically modified titanium (Ti) via Process I and the morphologies of OCP crystals formed at (b) no protein, (c) 50 and (d) 100 μg/ml rM179, (e) 50 and (f) 100 μg/ml BSA. [0028] FIG. 4 shows SEM micrographs of apatite (Ap) crystals initially induced by chemically modified titanium (Ti) after 4 h SCS1 immersion (a, c) and apatite coatings formed via Process II at (b, d) no protein, (e) 50 and (f) 100 μg/ml rM179, (g) 50 and (h) 100 μg/ml BSA. Images at (c) and (d) are respectively the higher magnifications of (a) and (b). [0029] FIG. 5 shows TEM images (a) of the apatite crystals formed via Process II in the presence of 100 μg/ml of rM179. The enlargement of the left bundle of crystals in (a) was shown in (b) and the corresponding SAED was shown in (c). The SAED pattern of apatite was indexed according to the standard JCPDS cards (1980, JCPDS International Center for Diffraction Data. Powder Diffraction File. Swarthmore, Pa.). [0030] FIG. 6 shows Tapping Mode AFM images of the untreated (as received) Bioglass surface (A) and those after 0.5 h of immersion in SCS1 rP172 (B) and 4 h of immersion in SCS1 b (C) and SCS1 rP172 (D). Arrows denote polishing scratches in A, apatite mineral in C and D; arrowheads indicate nanosphere assemblies in B. [0031] FIG. 7 shows SEM micrographs of the apatite crystals formed on Bioglass samples after incubation in PBS for 1 week and subsequent immersion in blank, BSA- and rM179-containing SCS2 for 3 days. DETAILED DESCRIPTION [0032] Throughout this disclosure, various publications, patents and published patent specifications are referenced by an identifying citation. The disclosures of these publications, patents and published patent specifications are hereby incorporated by reference into the present disclosure to more fully describe the state of the art to which this invention pertains. Definitions [0033] As used herein, certain terms have the following defined meanings. [0034] As used in the specification and claims, the singular form “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “an article” includes a plurality of articles. [0035] As used herein, the term “comprising” is intended to mean that the compositions and methods include the recited elements, but not excluding others. “Consisting essentially of” when used to define compositions and methods, shall mean excluding other elements of any essential significance to the combination. Thus, a composition consisting essentially of the elements as defined herein would not exclude trace contaminants from the isolation and purification method and pharmaceutically acceptable carriers, such as phosphate buffered saline, preservatives, and the like. “Consisting of” shall mean excluding more than trace elements of other ingredients and substantial method steps for administering the compositions of this invention. Embodiments defined by each of these transition terms are within the scope of this invention. [0036] The terms “polynucleotide” and “nucleic acid molecule” are used interchangeably to refer to polymeric forms of nucleotides of any length. The polynucleotides may contain deoxyribonucleotides, ribonucleotides, and/or their analogs. Nucleotides may have any three-dimensional structure, and may perform any function, known or unknown. The term “polynucleotide” includes, for example, single-stranded, double-stranded and triple helical molecules, a gene or gene fragment, exons, introns, mRNA, tRNA, rRNA, ribozymes, cDNA, recombinant polynucleotides, branched polynucleotides, plasmids, vectors, isolated DNA of any sequence, isolated RNA of any sequence, nucleic acid probes, and primers. A nucleic acid molecule may also comprise modified nucleic acid molecules. [0037] The term “peptide” is used in its broadest sense to refer to a compound of two or more subunit amino acids, amino acid analogs, or peptidomimetics. The subunits may be linked by peptide bonds. In another embodiment, the subunit may be linked by other bonds, e.g. ester, ether, etc. As used herein the term “amino acid” refers to either natural and/or unnatural or synthetic amino acids, including glycine and both the D or L optical isomers, and amino acid analogs and peptidomimetics. A peptide of three or more amino acids is commonly called an oligopeptide if the peptide chain is short. If the peptide chain is long, the peptide is commonly called a polypeptide or a protein. [0038] “Hybridization” refers to a reaction in which one or more polynucleotides react to form a complex that is stabilized via hydrogen bonding between the bases of the nucleotide residues. The hydrogen bonding may occur by Watson-Crick base pairing, Hoogstein binding, or in any other sequence-specific manner. The complex may comprise two strands forming a duplex structure, three or more strands forming a multi-stranded complex, a single self-hybridizing strand, or any combination of these. A hybridization reaction may constitute a step in a more extensive process, such as the initiation of a PCR reaction, or the enzymatic cleavage of a polynucleotide by a ribozyme. [0039] Examples of stringent hybridization conditions include: incubation temperatures of about 25° C. to about 37° C.; hybridization buffer concentrations of about 6×SSC to about 10×SSC; formamide concentrations of about 0% to about 25%; and wash solutions of about 6×SSC. Examples of moderate hybridization conditions include: incubation temperatures of about 40° C. to about 50° C.; buffer concentrations of about 9×SSC to about 2×SSC; formamide concentrations of about 30% to about 50%; and wash solutions of about 5×SSC to about 2×SSC. Examples of high stringency conditions include: incubation temperatures of about 55° C. to about 68° C.; buffer concentrations of about 1×SSC to about 0.1×SSC; formamide concentrations of about 55% to about 75%; and wash solutions of about 1×SSC, 0.1×SSC, or deionized water. In general, hybridization incubation times are from 5 minutes to 24 hours, with 1, 2, or more washing steps, and wash incubation times are about 1, 2, or 15 minutes. SSC is 0.15 M NaCl and 15 mM citrate buffer. It is understood that equivalents of SSC using other buffer systems can be employed. [0040] A polynucleotide or polynucleotide region (or a polypeptide or polypeptide region) has a certain percentage (for example, 80%, 85%, 90%, or 95%) of “sequence identity” to another sequence means that, when aligned, that percentage of bases (or amino acids) are the same in comparing the two sequences. This alignment and the percent homology or sequence identity can be determined using software programs known in the art, for example those described in CURRENT PROTOCOLS IN MOLECULAR BIOLOGY (F. M. Ausubel et al., eds., 1987) Supplement 30, section 7.7.18, Table 7.7.1. Preferably, default parameters are used for alignment. A preferred alignment program is BLAST, using default parameters. In particular, preferred programs are BLASTN and BLASTP, using the following default parameters: Genetic code=standard; filter=none; strand=both; cutoff=60; expect=10; Matrix=BLOSUM62; Descriptions=50 sequences; sort by=HIGH SCORE; Databases=non-redundant, GenBank+EMBL+DDBJ+PDB+GenBank CDS translations+SwissProtein+SPupdate+PIR. Details of these programs can be found at the following Internet address: ncbi.nlm.nih.gov/cgi-b in/BLAST. [0041] The term “isolated” means separated from constituents, cellular and otherwise, in which the polynucleotide, peptide, polypeptide, protein, antibody, or fragments thereof, are normally associated with in nature. For example, with respect to a polynucleotide, an isolated polynucleotide is one that is separated from the 5′ and 3′ sequences with which it is normally associated in the chromosome. As is apparent to those of skill in the art, a non-naturally occurring polynucleotide, peptide, polypeptide, protein, antibody, or fragments thereof, does not require “isolation” to distinguish it from its naturally occurring counterpart. In addition, a “concentrated”, “separated” or “diluted” polynucleotide, peptide, polypeptide, protein, antibody, or fragments thereof, is distinguishable from its naturally occurring counterpart in that the concentration or number of molecules per volume is greater than “concentrated” or less than “separated” than that of its naturally occurring counterpart. A polynucleotide, peptide, polypeptide, protein, antibody, or fragments thereof, which differs from the naturally occurring counterpart in its primary sequence or for example, by its glycosylation pattern, need not be present in its isolated form since it is distinguishable from its naturally occurring counterpart by its primary sequence, or alternatively, by another characteristic such as glycosylation pattern. Although not explicitly stated for each of the inventions disclosed herein, it is to be understood that all of the above embodiments for each of the compositions disclosed below and under the appropriate conditions, are provided by this invention. Thus, a non-naturally occurring polynucleotide is provided as a separate embodiment from the isolated naturally occurring polynucleotide. A protein produced in a bacterial cell is provided as a separate embodiment from the naturally occurring protein isolated from a eucaryotic cell in which it is produced in nature. [0042] A “subject” is a vertebrate, preferably an animal or a mammal, more preferably a human. Mammals include, but are not limited to, murines, simians, humans, farm animals, sport animals, and pets. [0043] A “control” is an alternative subject or sample used in an experiment for comparison purpose. A control can be “positive” or “negative”. For example, where the purpose of the experiment is to determine a correlation between concentration of amelogin-type protein and crystal formation, it is generally preferable to use a positive control (a sample having a previously determined correlation), and a negative control (a sample lacking amelogin-type protein). [0044] A “composition” is intended to mean a combination of active agent and another compound or composition, inert (for example, a detectable agent or label) or active, such as an adjuvant. [0045] A “pharmaceutical composition” is intended to include the combination of an active agent with a carrier, inert or active, making the composition suitable for diagnostic or therapeutic use in vitro, in vivo or ex vivo. [0046] As used herein, the term “pharmaceutically acceptable carrier” encompasses any of the standard pharmaceutical carriers, such as a phosphate buffered saline solution, water, and emulsions, such as an oil/water or water/oil emulsion, and various types of wetting agents. The compositions also can include stabilizers and preservatives. For examples of carriers, stabilizers and adjuvants, see Martin REMINGTON'S PHARM. SCI., 15th Ed. (Mack Publ. Co., Easton (1975)). [0047] All numerical designations, e.g., pH, temperature, time, concentration, and molecular weight, including ranges, are approximations which may be varied (+) or (−) by increments of 0.1. It is to be understood, although not always explicitly stated that all numerical designations are preceded by the term “about”. It also is to be understood, although not always explicitly stated, that the reagents described herein are merely exemplary and that equivalents of such are well known in the art. [0048] An “effective amount” is an amount sufficient to effect beneficial or desired results. An effective amount can be administered in one or more administrations, applications or dosages. [0049] The invention provides a method for coating articles suitable for dental or prosthetic implantation with an enamel-like biomaterial. The phrase “enamel-like” refers to the similarities to natural enamel, in terms of strength and crystal habit, as well as the bioactive properties of the coating, relative to other synthetic derivatives created without the use of amelogenin-like proteins. The bioactivity of the enamel-like coating manifests itself at least partly in the coating's advantageous ability to promote the ingrovth of natural bone and/or oral tissue around the coated prosthesis. During the natural growth of bone and teeth, a soft extracellular organic matrix serves as a dynamic scaffold to control and facilitate the formation of highly ordered, remarkably elongated carbonated apatite crystals while it is being progressively degraded, leading to a mature enamel composed of more than 95 wt % inorganic minerals (Fincham et al. 1999, J Struct Biol, 122, 320-327). The fusion of natural bone and/or tooth enamel to the coated implants provided by the present invention will provide the implants with greater strength, durability and overall utility. [0050] Without being bound by this proposed mechanism of action, the bioactive properties of the coated inserts produced by the methods of the invention are the result, at least partially, of the presence of amelogenin-type proteins in the calcifying solutions used in the method. Amelogenins are the major protein component of the developing dental enamel, accounting for about 90% of the extracellular organic matrix (Termine et al. 1980, J. Biol. Chem., 255, 9760). The primary structures of amelogenins are highly conserved across species (Fincham et al. 1997, Dental Enamel—Ciba Foundation Symposium 205, D. J. Chadwick, and G. Cardew (Eds.), John Wiley & Sons, Chichester, 118). The parent or full-length amelogenin molecule is comprised of the following three regions: (i) an N-terminal sequence of some 44-45 residues (referred to as TRAP, for Tyrosine-Rich Amelogenin Polypeptide); (ii) a hydrophobic core sequence of some 100-130 residues enriched in proline, leucine, methionine and glutamine; and (iii) an acidic hydrophilic C-terminal sequence of some 15 residues (Fincham et al. 1997, Dental Enamel—Ciba Foundation Symposium 205, D. J. Chadwick, and G. Cardew (Eds.), John Wiley & Sons, Chichester, 118). The hydrophilic C-terminal of the parent amelogenin is proteolytically cleaved shortly after secretion (Fincham et al. 1996, Connect. Tissue Res., 35, 151). Other amelogenin isoforms in the extracellular matrix include the proteolytic product (TRAP) and a few alternative splice products such as the leucine-rich amelogenin polypeptide (LRAP). The term “amelogenin-type proteins” refers to members of this protein family and their natural or synthetic derivatives, for example, as described herein as having the same or similar ability to enhance or modulate crystal formation compared to rM179. One skilled in the art will recognize suitable members of this family according to their amino acid sequences and their effects on bone and/or tooth development in vivo and in vitro. For example, amino acid sequences with 40% or more identity to mouse amelogenin are considered homologs and are expected to have the similar structures and functions. [0051] LRAP is identical to the full-length amelogenin protein at its two termini but lacks a large central segment of the protein (Gibson et al. 1991, Biochem. Biophys. Res. Comm., 174, 1306; Brookes et al. 1995, Archs. Oral Biol., 40, 1). Examples of amino acid sequences of TRAP, LRAP and a recombinant murine amelogenin rM179 are shown in Table 1 (Tan et al. 1998, J. Dent. Res., 77, 1388). The full-length rM179 is analogous to the secreted full-length mouse amelogenin M180 lacking only the amino-terminal Met1 and phosphorylation of Ser16. Recombinant rM166 was engineered to create the amelogenin lacking the hydrophilic C-terminal 12 amino acids (Simmer et al. 1994, Calcif. Tissue Int., 54, 312). TABLE 1 Amino acid sequences of amelogenins. (M)   PLPPHPGSPGYINLSYEVLTPLKWYQSMI 30 RQP YPSYGYEPMGGW↓LHHQIIPVLSQQHPP 60              TRAP SHTLQPHHHLPVVPAQQPVAPQQPMMPVPG 90 HHSMTPTQHHQPNIPPSAQQPFQQPFQPQA 120 IPPQSHQPMQPQSPLHPMQPLAPQPPLPPL 150 FSMQ PLSPILPELPLEA ↓ WPATDKTKREEVD 180                rM166        rM179 The amino acid sequence of LRAP is underlined. The arrow above “TRAP” indicates the location of the C′-terminal residue of TRAP; the arrow above “rM166” indicates the C′terminal residue of rM166. rM179 consists of the entire sequence shown above, except for the initiating methionine (shown in parentheses). [0052] Amelogenin proteins have been found to self-assemble in vitro under suitable aqueous conditions to form quasi-spherical quaternary aggregate structures (nanospheres) (Fincham et al. 1995, J. Struct. Biol., 115, 50; Moradian-Oldak et al. 2000, J. Struct. Biol., 131, 27). These nanosphere structures have been postulated to be of great importance in creating an ultrastructural microenvironment for the controlled formation of highly ordered elongated apatite crystals in enamel (Moradian-Oldak 2001, Matrix Biol., 20, 293; Wen et al. 2001, Matrix Biol., 20, 387). [0053] Researchers have attempted to utilize amelogenins to in vitro calcifying systems, which allow the crystal growth of apatite or octacalcium phosphate (OCP) grown from supersaturated calcifying solutions (SCSs) at ambient temperatures. OCP has been proposed to be a potent precursor for natural enamel crystallites (Brown 1979, J. Dent. Res. Special Issue, 58B, 857). The previously observed effects of amelogenins on the kinetics of apatite crystal growth and the morphology of OCP are described in the following references: Doi et al. 1984, J. Dent. Res., 63, 98; Aoba et al. 1987, Calcif. Tissue Int., 41, 281; Moradian-Oldak et al. 1998, Biopolymers, 46, 225; Hunter et al. 1999, Calcif. Tissue Int., 65, 226; Wen et al. 2000, J. Dent. Res., 79, 1902; Iijima et al. 2001, J. Crystal Growth, 222, 615; Iijima et al. 2002, J. Dent. Res., 81, 69. [0054] One frequently employed system was seeded crystal growth of apatite in which extracted enamel or synthetic hydroxyapatite (HA) crystals were dispersed into SCSs containing 3-68 μg/ml of amelogenins (Aoba et al. 1987, Calcif. Tissue Int., 41, 281; Moradian-Oldak et al. 1998, Biopolymers, 46, 225; Doi et al. (Doi et al. 1984, J. Dent. Res., 63, 98) concluded that the seeded enamel crystal growth was inhibited mainly by the central portion of the amelogenin molecule through their study of a series of bovine amelogenins of different molecular weights from 5,000 to 27,000. Aoba et al. (Aoba et al. 1987, Calcif. Tissue Int., 41, 281) and Moradian-Oldak et al. (Moradian-Oldak et al. 1998, Biopolymers, 46, 225) observed that the parent or the full-length amelogenin was found to have a slight inhibitory effect on apatite crystal growth most likely due to some adsorption affinity of its hydrophilic carboxy-terminal motif on apatite. The inhibition became insignificant after the proteolytic cleavage of this hydrophilic region. Additionally, rM179 appeared to have an adherence effect on growing apatite crystals, presumably through its molecular self-association (Moradian-Oldak et al. 1998, Biopolymers, 46, 225). [0055] The coating of the present invention is typically applied in thin layers uniformly across the surface of the substrate. In certain embodiments, e.g., where the substrate to be coated is immersed in the amylogenin-containing calcifying solutions, the method allows for the uniform coating of complex surfaces including porous surfaces and recessed surfaces. The geometry of the substrate surfaces, which may be crucial to the effectiveness of the substrate upon implantation, should not be affected by immersion coating. [0056] According to one embodiment of the method, the substrate is contacted with a supersaturated calcifying solution, wherein the solution comprises an effective amount of an amelogenin-type protein. An “effective amount” is an amount of amelogenin sufficient to substantially modify the growth of hydroxapatite or octacalcium phosphate crystals on the surface of the substrate. In one aspect a concentration of at least approximately 10 μg/ml amelogenin is used. Alternatively, concentrations greater than 100 μg/ml are used to profoundly modify the crystals. [0057] The method is applied to a variety of substrates, including silicon, metals, ceramics and polymers. In particular, the method is useful for coating substrates which are intended for medical implantation, e.g., bone and dental prostheses. Such substrates are typically fashioned of strong biocompatible materials such as titanium metal. The method is compatible with other metals, including titanium alloy, tantalum, tantalum alloy, stainless steel and cobalt chromium alloy. Other well-known biocompatible materials such as ultra high molecular weight polyethylene, hydroxyapatite, Bioglass and Glass Ceramic A-W, may also be used. [0058] In one aspect, the substrate is pre-treated prior to coating. Any treatment that modifies the surface of the substrate to facilitate crystal formation is a suitable pre-treatment, e.g., chemically treating the metal to form nanopockets. Titanium samples, for example, can be cleaned ultrasonically and “etched” prior to immersion in the supersaturated calcifying solution. Etching roughens the surface of titanium and facilitates crystal growth. Etching may be accomplished by various means including, without limitation, chemical, physical or thermal means. One example of chemical etching involves treatment of a metal, e.g., titanium, with hydrofluoric acid, followed by immersion in sodium hydroxide. In some embodiments, the substrate is well rinsed before contact with the calcifying solution. This method forms nano-sized pores on the surface of the substrate which facilitate the induction of calcium phosphate crystal growth. Other substrates, such as Bioglass, do not require hydrofluoric acid etching for crystal growth. One skilled in the art will recognize what steps are necessary to prepare the substrate for coating by referring to the literature in which the properties of the preferred implantable substrates are well-known and documented. Such steps are analogous to, and may include, crystal seeding and doping procedures. [0059] The supersaturated calcifying solution of the invention comprises an aqueous solution having a pH in the range of about 5 to about 10, or alternatively a pH in the near-physiological range, e.g., about 6.5 to about 8. The solution contains at least calcium ions and phosphate ions, but may contain other ions, particularly physiologically relevant ions including, but not limited to, magnesium, sodium, chlorine, sulfate, potassium and carbonate. The pH of the solution may be maintained by a buffer such as Tris or any other chemical which provides effective buffering capability in the near-physiological pH range. The coating process is carried out typically at temperatures in the physiological range, e.g., approximately 35 to approximately 40 degrees Celsius, but may be carried out ambient temperatures from approximately 10 to approximately 35 degrees. In certain embodiments of the coating method, coating takes place at ambient atmospheric pressure. [0060] Concentrations of ions in the supersaturated calcifying solution are in the range of, e.g., 100 to 200 mM Na + , 3-5 mM K + , 1-3 mM Ca 2+ , 100 to 250 mM Cl − , 1 to 2.5 mM HPO 4 2− , 1-2 mM SO 4 2− , and 1 to 100 mM Tris. The ionic strength of the solution is typically in the range of 100 to 200 mM, but useful coating may be achieved concentrations outside that range. The solution may be prepared by dissolving analytical grade chemicals, e.g., CaCl 2 .2H 2 O, Ca(NO 3 ) 2 .4H 2 O, Na 2 HPO 4 .7H 2 O, NaCl, KNO 3 , KH 2 PO 4 , in deionized water. One skilled in the art will recognize that other suitable compounds may be dissolved to achieve the same desired concentrations of ions. Other biologically relevant ions, such as magnesium or silicate, may be added or substituted for the ions listed above. Growth of the enamel-like biomaterial is primarily dependent on the presence of calcium and phosphate ions. Purified recombinant amelogenin or native amelogenin are first dissolved at higher concentrations in a buffered solution, then added to the calcifying solution to reach the desired final concentration. In another embodiment of the method, therapeutic agents including antibiotics, growth factors, or anti-inflammatory agents, are added to the supersaturated calcifying solution so that the agents are incorporated into the enamel-like coating. [0061] The substrate, or a desired portion of the substrate, is immersed in the supersaturated calcifying solution for the length of time needed to produce the desired amount of enamel-like coating on the surface of the substrate. Typically, the substrate will be in contact with the solution for at least one hour, and more typically for one to seven days. The length of time will vary depending on such recognizable factors as the amount of coating desired, the particular concentrations of ions present in the calcifying solution, the particular amount of amelogenin present, pecularities of the substrate surface, the solution pH and the ambient temperature and pressure. [0062] In one embodiment of the coating method, the substrate to be coated is first contacted with a supersaturated calcifying solution which is substantially free of any amelogenin-type protein. As used herein, the term “substantially free” comprises any concentration that will not affect crystal formation. In one aspect, amelogenin-like proteins are not present in the solution, or are present only in insignificant concentrations (e.g., 1 μg/ml or less). As is apparent to those skilled in the art—the specific amount of protein that can be present without affecting crystal formation varies with the substrate, the solution, the pH, ionic strength and the concentration of protein contained within the second contacting solution. After a period of incubation in contact with this first solution, the substrate is contacted with the amelogenin-containing solution discussed above. The first amelogenin-free solution may comprise ions and ion concentrations similar to the solution containing amelogenin. Typically, the first amelogenin-free solution will comprise higher concentrations of K + (e.g., between 75 and 200 mM) and NO3- (e.g., between 75 and 200 mM) and approximately half the concentration of Ca 2+ and HPO 4 2− . According to this embodiment, the first incubation continues at 37 degrees Celsius for 1 to 24 hours, but typically between 2 and 10 hours or between 3 and 5 hours. [0063] The methods described above yield a novel enamel-like biomaterial, the properties of which are influenced by the presence of the amelogenin-type protein in the calcifying solution. As natural enamel in the body is characterized by the presence of elongated crystals, practitioners of the method will frequently desire that the synthetic enamel-like coating also comprises elongated crystals. The methods disclosed herein are capable of creating enamel-like coatings which consist of submicron bundles of elongated apatite crystals with an average aspect ratio (length/width) of at least two. In addition, analysis of the reactions shows that the resultant coating comprises approximately 1×10 −4 % to 10% w/w amelogenin-type protein. [0064] Without further elaboration, it is believed that one skilled in the art can follow the preceding description and utilize the present invention to its fullest extent. The following examples of specific embodiments are, therefore, to be construed as merely illustrative and are not intended to limit the disclosure in any way. EXAMPLES Example 1 Coating of Titanium with Enamel-Like Biomaterial Comprising Amelogenin [0065] Materials and Methods. [0066] Recombinant murine amelogenin rM179 was expressed, purified and characterized as previously described (Simmer et al. 1994, Calcif Tissue Int, 54, 312-319). The rM 179 protein is analogous to the secreted full-length mouse amelogenin M180 lacking only the amino-terminal Met1 and phosphorylation of Ser16 (Fincham et al. 1993, Biochem Biophys Res Comm, 197, 248-255). Bovine serum albumin (BSA) purchased from Sigma Chemicals (A-4503, Lot77H0504) was used as a control protein for inhibitory activity, which has been well documented previously (Robinson et al. 1992, J Dent Res, 71, 1270-1274; Radin et al. 1996, J Biomed Mater Res, 30, 273-279). Titanium samples of 10×10×1.3 mm were cut from the commercially pure titanium sheet (Titanium Industries, Grade 2, ASTM B265). Two types of SCSs were prepared from analytical-grade CaCl 2 .2H 2 O, Ca(NO 3 ) 2 .4H 2 O, Na 2 HPO 4 .7H 2 O, NaCl, KNO 3 , KH 2 PO 4 to achieve the ion concentrations listed in Table 2. [0067] SCSs containing rM179 or BSA were made by dissolving the protein into the blank SCSs at concentrations ranging from 12.5 to 100 μg/ml. Titanium samples were ultrasonically cleaned in distilled-deionized water (DDW), acetone, 70% ethanol solution for 20 min each, and in DDW again for 10 min. The cleaned samples were etched with 10 ml 10% HF solution for 30 min, immersed in 40 ml 2 N NaOH solution at 85° C. for 5 h and completely rinsed with DDW. Two SCSs (SCS1 and SCS2) were employed for growing apatite crystals on the chemically modified titanium. The pH of SCS1 was 7.4 at room temperature and that of SCS2 was maintained to be 7.4 at 37° C. by using a Metrohm 718 pH-STAT during the crystal growth experiments. The OCP and apatite crystal growth on titanium was respectively achieved through the following two processes. Process I: Immersion of the chemically treated titanium samples in blank, rM179- or BSA-containing SCS1—(20 ml per sample at 37° C. for 1 d). Process II: Pre-incubation of the samples in blank SCS1—(20 ml per sample at 37° C. for 4 h) followed by an immersion in blank, rM179- or BSA-containing SCS2—(40 ml per sample at 37° C. for 3 d). [0068] The protein concentrations of those SCSs containing rM179 and BSA before and after the crystal growth experiments were measured using reverse phase high performance liquid chromatography (HPLC, Vydac, C4-214TP54 column, Separations Group, Hesperia, Calif., USA). All the samples were rinsed with DDW, air-dried, and characterized by means of X-ray diffraction (XRD, Rigaku, Cu Kα radiation at 50 kV/70 mA), scanning electron microscopy (SEM, Cambridge 360, at 15 kV), and transmission electron microscopy (TEM, JOEL, JEM-1200EM) coupled with selected area electron diffraction (SAED), as previously described (Wen et al. 2000, J Biomed Mater Res, 52, 762-773). [0069] Results. [0070] SEM micrographs of an untreated (as received) titanium surface, and those after HF and NaOH treatment are shown in FIG. 1 . It was noted that the HF etching increased the roughness of titanium surface for the emerging of nanosized structures ( FIG. 1 b ). Nano-sized pores were formed at the sample surface by the subsequent NaOH immersion ( FIG. 1 c ). The two-step chemical treatment of titanium samples was performed to create a bioactive-—Ca—P inductive—surface. All the samples were completely coated by a mineral layer after different immersion procedures as indicated by their representative XRD patterns in FIG. 2 . The formation of a nanometer scaled porous oxide layer formed at titanium surface after the chemical treatment was the key to the mineral initiation from the SCS1 (Wen et al. 1998, J Mater Sci Mater Med, 9, 121-128; Wen et al. 1998, J Crystal Growth, 186, 616-623). [0071] As determined by the X-ray diffraction patterns in FIG. 2 a very thin layer of apatite was nucleated on the sample surface followed by the growth of OCP crystals in Process I ( FIG. 2 a - c ) while apatite was the only mineral phase developed in Process II ( FIG. 2 d - f ). Only titanium peaks were detected in the pattern of chemically modified titanium ( FIG. 2 h ) but apatite crystals were formed after 4 h immersion in blank SCS1 ( FIG. 2 g ). The XRD patterns of OCP/apatite formed from Process I ( FIG. 2 a - c ) were similar to one another regardless of the presence of different concentrations of different proteins, so were the XRD patterns of apatite formed from Process II ( FIG. 2 d - f ). [0072] FIG. 3 represents the SEM micrographs of the cross sections of the Ca—P coatings ( FIG. 3 a ) and the morphology of OCP crystals formed on the chemically modified titanium by process I, in the absence ( FIG. 3 b ), and presence of amelogenin ( FIG. 3 c - d ) and albumin ( FIG. 3 e - f ). After 1 day of immersion in blank SCS1 about 15-μm thick OCP crystal layer was precipitated on titanium. The crystals were seen in the characteristic plated-like shape of OCP and measured ˜200 nm thick and several microns across ( FIG. 3 b ). The application of rM179 showed no significant inhibitory effect on either the morphology or sizes of OCP crystals over the concentration range of 12.5-100 μg/ml ( FIG. 3 c - d ), whereas the presence of BSA significantly altered the plated-like OCP crystals into a round edged, curved shape indicating a general inhibitory effect ( FIG. 3 e - f ). [0073] FIG. 4 is the SEM micrographs of apatite crystals grown by process II in the absence ( FIG. 4 a - d ) and the presence of amelogenin ( FIG. 4 e - f ) and albumin ( FIG. 4 g - h ). The apatite crystals developed from Process II without applying any proteins were observed under SEM to be in a slightly curved platy shape, mostly less than 2 μm across ( FIG. 4 a - d ). Regardless of the concentration applied, BSA showed dramatic inhibition as indicated by the significantly reduced crystal sizes ( FIG. 4 g - h ). Interestingly, the effects of rM179 appeared to be dose dependent. No significant effect was observed at a concentration of 50 μg/ml ( FIG. 4 e ). However, at higher concentration, e.g., 100 μg/ml, amelogenin remarkably modulated the plated-like crystals into submicron-sized structures ( FIG. 4 f ). These were characterized by TEM in combined with SAED to be bundles of elongated apatite crystals with a preferential orientation of 002 (c-axis) ( FIG. 5 ). [0074] Table 3 summarizes the consumption rate (%) of recombinant amelogenin rM179 and BSA during OCP and apatite crystal growth on titanium surface. rM179 is consumed during the OCP and apatite crystal growth very differently from BSA. There was more BSA absorbed by OCP crystals than apatite crystals while much more rM179 was incorporated into the apatite than OCP crystal layers. TABLE 2 Concentrations (mM) of ions present in the PBS and two SCSs employed for Ca—P crystal growth on biomaterials. Ion SCS1 SCS2 Na + 136.8 — K + 3.71 144.6 Ca 2+ 3.10 1.5 Cl − 185.5 — HPO 4 2− 1.86 0.9 NO 3 − — 145.8 Tris 50 [0075] TABLE 3 Consumptions (%) of rM179 and BSA during OCP and apatite crystal growth on titanium analyzed by HPLC. Protein OCP Apatite rM179-50 μg/ml 27 97.5 rM179-100 μg/ml 22.5 78 BSA-50 μg/ml 32 7 BSA-100 μg/ml 25 9 Example 2 Coating of Bioglass® with Enamel-Like Material Comprising Amelogenin [0076] Materials and Methods. [0077] Bioactive (Ca—P inducible) materials may serve as the substrates for apatite crystal growth from SCSs. One of these advanced biomaterials is bioactive glass, which induces apatite formation by immersion in a buffer solution of Tris-HCl or phosphate buffered saline (PBS) (Zhong et al. 1997, Transactions of the 23rd Annual Meeting of the Society for Biomaterials, 125). 45S5 type Bioglass® discs were provided by USBiomaterials Corporation. This material has been clinically applied for over 7 years as bone graft materials, especially in periodontal defect repair (Hench 1994, Bioceramics 7, Ö. H. Andersson, and A. Yli-Urpo (Eds.), Butterworth-Heinemann Ltd., Oxford, 3; Hench et al. 1996, Life Chem. Rep., 13, 187). [0078] A PBS and two SCSs (SCS1 and SCS2) were employed for growing apatite crystals on the Bioglass discs. The detailed compositions of PBS, SCS1 and SCS2 are listed in Table 4. The pH of both PBS and SCS1 were 7.4 at room temperature and that of SCS2 were always maintained to be 7.4 at 37° C. The rM179 and rP172 proteins were prepared as previously described by Simmer et al. (Simmer et al. 1994, Calcif. Tissue Int., 54, 312) and Ryu et al. (Ryu et al. 1999, J. Dent. Res., 78, 743). Bovine serum albumin (BSA) was used as a control protein for inhibitory activity, which has been well documented previously (Radin et al. 1996, J. Biomed. Mater. Res., 30, 273; Gilman et al. 1994, J. Inorganic. Biochem., 55, 3142-44). The concentration applied in the SCSs for all the proteins was 50 μg/ml. The apatite crystal growth on Bioglass was achieved in the following two ways: (1) Direct Immersion: Immersing the samples in blank and rP172-containing SCS1 (SCS1 b and SCS1 rM172 ) at 37° C. for 0.5, 1, 2 or 4 h; (2) PBS Pre-incubation: Incubating the samples in PBS at 37° C. for 1 week followed by immersions in blank, BSA- or rM179-containing SCS2 (SCS2 b , SCS2 BSA and SCS2 rM179 ) at 37° C. for 3 d. TABLE 4 Concentrations (mM) of ions present in the PBS and two SCSs employed for Ca—P crystal growth on biomaterials Ion PBS SCS1 SCS2 Na + 157.2 136.8 — K + 4.44 3.71 144.6 Ca 2+ — 3.10 1.5 Cl − 139.6 185.5 — HPO 4 2− 11.9 1.86 0.9 NO 3 − — — 145.8 Tris — 50 — [0079] Direct Immersion. [0080] The surface transformation of Bioglass observed in SCS1 b was in a good consistence with the general reaction sequence occurred at bioactive glass surfaces during implantation or in vitro immersion (Hench 1998, J. Am. Ceram. Soc., 81, 1705). The smooth sample surface as imaged by atomic force microcopy (AFM) ( FIG. 6A ) was changed to be very rough after 0.5 h of immersion because of the glass network dissolution. Spherical silica-gel particles with diameters of 150-300 nm consisting of substructures of 20-60 nm across were formed after 1 h of immersion. The chemisorption of amorphous Ca—P and crystallization of nanophase apatite occurred epitaxially on the silica-gel structures during 1-4 h of immersion. The presence of rP172 dramatically modulated the Bioglass surface reaction during SCS1 rP172 immersion. In the first 0.5 h of immersion, more than 95% of rP172 protein in solution was adsorbed onto the sample surfaces as determined by analytical reverse phase high performance liquid chromatography (HPLC). It was indicated in FIG. 6B that the protein self-assembled into spherical assemblies of 10-60 nm in diameters. During 0.5-4 h of SCS1 rp172 immersion, the protein assemblies of rP172 remarkably induced the formation of orientated silica-gel plates (about 100 nm wide and 50 nm thick) and subsequently of platy apatite minerals ( FIG. 6D ), which were obviously different from those formed in SCS1 b ( FIG. 6C ). Under TEM, the apatites grown after 2-4 h of SCS1 b immersion were revealed to be rod crystals that measured about 100 nm thick and 500 nm long. However, it appeared that the crystals formed after 2-4 h of SCS1 rP172 immersion all adopted an elongated shape. They were in a length comparable to the crystals formed in SCS1 b but significantly reduced thickness only about 5-7 nm. The highly organized long and thin crystals observed after 4 h of SCS1 rP172 immersion strikingly resembled the apatite crystals observed in the early stage of enamel biomineralization (Fincham et al. 1995, J. Struct. Biol., 115, 50; Diekwisch et al. 1995, Cell Tissue Res., 279, 149). [0081] PBS Pre-Incubation. [0082] Mineral layers precipitated on all the treated samples were characterized to be apatite by X-ray diffraction (XRD) and Fourier transmission infrared spectroscopy (FTIR). FIG. 6 presents scanning electron microscopy (SEM) images of the apatites formed after different immersions. Plate-shaped crystals (˜50 nm thick and 300-600 nm across) were observed on the samples after PBS incubation. The crystals grown from SCS2 b were of the typical plate shape except for a slight increased thickness, while needle-shaped crystals (200-300 nm long and 50-70 nm thick) were precipitated on the SCS2 BSA -immersed samples. It was surprising to observe that the apatites deposited on the SCS2 rM 179-immersed samples adopted an elongated, curved shape (˜500 nm long and ˜120 nm thick). They were revealed by transmission electron microscopy (TEM) to be bundles of lengthwise crystals (15-20 nm thick) orientated parallel to one another, much alike the long and thin crystals observed in the very early stage of tooth enamel formation (Fincham et al. 1995, J. Struct. Biol., 115, 50; Diekwisch et al. 1995, Cell Tissue Res., 279, 149). The modulating effects of rM179 on apatite crystals are distinctly different from the overall inhibition of BSA. [0083] Atomic force microscopic study has revealed a progressive accretion of rM179 molecules during nanospheres assembly in a Tris-HCl buffer at concentrations from 12.5 to 300 μg/ml (Wen et al. 2001, Matrix Biol, 20, 387-35). At low concentrations (12.5-50 μg/ml), nanospheres with diameters varying from 7 to 53 nm were identified while at concentrations between 100-300 μg/ml the size distribution was significantly narrowed so that nanosphere diameters were consistently between 10 and 25 nm. These nanospheres were observed to be the basic building blocks of both engineered rM179 gels and the developing enamel extracellular matrix. We infer that the stable 15-20 nm nanosphere structures generated in the presence of high concentrations of amelogenins may be of great importance in creating a highly organized ultrastructural microenvironment required for the formation of initial enamel apatite crystallites or synthesizing materials having enamel-like structures.

The invention provides novel dental enamel inspired materials for biomedical and dental applications. The materials are apatite-like calcium phosphate complexes and may comprise apatite, octacalcium phosphate crystals, or mixtures thereof. In one embodiment, the materials (calcium phosphate coatings) are mixtures of crystals of apatite and its precursor, octacalcium phosphate, nucleated on a titanium surface. They are prepared using a chemical process leading to the formation of biological apatite which is similar to that found in natural bone and teeth. In one embodiment, the materials are prepared by placing a titanium substrate in a supersaturated calcifyng solution containing native or purified recombinant amelogenins. The presence of the amelogenins modulates apatite crystal growth to mimic in vivo apatite crystal formation. Applications for the materials include, without limitation, dental tissue (enamel, dentin, cementum) replacement, orthopeadic implants for bone repair, and coatings for improving the biocompatibility and bone regeneration capability of currently available implants or medical devices made of metallic, polymeric, ceramic or composite materials.

BACKGROUND [0001] Annually in the United States, over 70 million corn acres are planted by approximately 40,000 growers, resulting in over 12 billion bushels of corn harvested annually, which, in-turn, translates into annual revenues in excess of $20 billion. Many growers recognize that one of the most influential and controllable factors affecting the productivity of each acre planted is the quality of seed placement. If a grower can be provided with more information earlier about seed placement quality while planting, the grower will be able to make earlier corrections or adjustments to the planter or its operation which could increase production by three to nine bushels per acre, which at today's prices translates into an additional $9.00 to $27.00 of additional income per acre at no cost. The net gain to growers and the US economy from such production increases would amount to hundreds of millions of dollars annually. [0002] Although existing monitors may warn the planter operator about certain “yield-robbing events,” many operators simply ignore the warnings or delay making any corrections or adjustments until it is convenient for the operator to do so (such as at the end of the field or when refilling the hoppers, etc.). The lack of motivation to take immediate corrective action may be due to the operator not knowing or not fully appreciating the extent of economic loss caused by the yield robbing event. Another possibility may be that because most existing planter monitors provide only broad averages across the entire planter in terms of seeds per acre or singulation percentage, the operator may not know that a particular row is suffering from a yield robbing event if the overall average population or singulation appears to be inline with the target or desired values. [0003] “Yield-robbing events” are generally caused by one of two types of errors, namely, metering errors and placement errors. Metering errors occur when, instead of seeds being discharged one at a time, either multiple seeds are discharged from the meter simultaneously (typically referred to as “multiplies” or “doubles”), or when no seed is discharged from the meter when one should have been (typically referred to as a “skip”). It should be appreciated that seed multiples and seed skips will result in a net loss in yield when compared to seeds planted with proper spacing because closely spaced plants will produce smaller ears due to competition for water and nutrients. Similarly, seed skips will result in a net loss in yield even though adjacent plants will typically produce larger ears as a result of less competition for water and nutrients due to the missing plant. [0004] Placement errors occur when the travel time between sequentially released seeds is irregular or inconsistent as compared to the time interval when the seeds were discharged from the seed meter, thereby resulting in irregular spacing between adjacent seeds in the furrow. Placement errors typically result from seed ricochet within the seed tube caused by the seed not entering the seed tube at the proper location, or by irregularities or obstructions along the path of the seed within the seed tube, or due to excessive vertical accelerations of the row unit as the planter traverses the field. [0005] Beyond metering errors and placement errors, another yield robbing event is attributable to inappropriate soil compaction adjacent to the seed, either due to inadequate down pressure exerted by the gauge wheels on the surrounding soil or excessive down pressure exerted by the gauge wheels. As discussed more thoroughly in commonly owned, co-pending PCT Application No. PCT/US08/50427, which is incorporated herein in its entirety by reference, if too little downforce is exerted by the gauge wheels or other depth regulating member, the disk blades may not penetrate into the soil to the full desired depth and/or the soil may collapse into the furrow as the seeds are being deposited resulting in irregular seed depth. However, if excessive down force is applied, poor root penetration may result in weaker stands and which may place the crops under unnecessary stress during dry conditions. Excessive downforce may also result in the re-opening of the furrow affecting germination or causing seedling death. [0006] While some experienced operators may be able to identify certain types of corrective actions needed to minimize or reduce particular types of yield robbing events once properly advised of their occurrence and their economic impact, other operators may not be able to so readily identify the type of corrective actions required, particularly those with less planting experience generally, or when the operator has switched to a new make or model planter. [0007] Accordingly, there is a need for a monitor system and method that is capable of providing the operator with near real-time data concerning yield robbing events and the economic cost associated with such yield robbing events so as to motivate the operator to take prompt corrective action. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 is a schematic illustration of a preferred embodiment of a planter monitor system of the present invention for monitoring the operation and performance of a planter. [0009] FIG. 2 is a perspective view of convention row crop planter. [0010] FIG. 3 is a side elevation view of a row unit of the conventional row crop planter of FIG. 2 . [0011] FIG. 4 is a perspective view of the gauge wheel height adjustment mechanism of the conventional row crop planter of FIG. 2 . [0012] FIG. 5 is an example of the preferred Level 1 Screen display for a monitor system in accordance with the present invention showing a preferred format for reporting overall planter performance details. [0013] FIG. 6 is an example of the preferred embodiment of a Level 2 Population Details screen display for the monitor system of FIG. 5 showing a preferred format for reporting population performance by row. [0014] FIG. 7 is an example of the preferred embodiment of a Level 2 Singulation Details screen display for the monitor system of FIG. 5 showing a preferred format for reporting singulation performance by row. [0015] FIG. 8 is an example of the preferred embodiment of a Level 2 Placement Details screen display for the monitor system of FIG. 5 showing a preferred format for reporting placement performance by row. [0016] FIG. 9 is an example of the preferred embodiment of a Level 3 Row Detail screen display for the monitor system of FIG. 5 showing a preferred format for reporting specific row performance details. [0017] FIG. 10 is an example of a Row Selection screen display for the monitor system of FIG. 5 showing a preferred format for selecting a row of the planter to view additional details of that row such as identified in FIG. 6 . [0018] FIG. 11 is an example of a screen display for the monitor system of FIG. 5 showing a preferred format for setup and configuration. [0019] FIG. 12 is an example of a screen display for selecting or inputting crop type during setup. [0020] FIG. 13 is an example of a screen display for inputting population settings during setup. DETAILED DESCRIPTION [0021] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 1 is a schematic illustration of a preferred embodiment of a planter monitor system 1000 of the present invention for monitoring the operation and performance of a planter 10 . As is conventional, the preferred planter monitor system 1000 includes a visual display 1002 and user interface 1004 , preferably a touch screen graphic user interface (GUI). The preferred touch screen GUI 1004 is preferably supported within a housing 1006 which also houses a microprocessor, memory and other applicable hardware and software for receiving, storing, processing, communicating, displaying and performing the various preferred features and functions as hereinafter described (hereinafter, collectively, the “processing circuitry”) as readily understood by those skilled in the art. [0022] As illustrated in FIG. 1 , the preferred planter monitor system 1000 preferably cooperates and/or interfaces with various external devices and sensors as hereinafter described, including, for example, a GPS unit 100 , a plurality of seed sensors 200 , one or more load sensors 300 , one or more inclinometers 400 , vertical accelerometers 500 , horizontal accelerometers 600 , vacuum sensors 700 (for planters with pneumatic metering systems), or any other sensor for monitoring the planter or the environment that may affect planting operations. [0023] FIG. 2 illustrates a conventional row-crop planter 10 such as a John Deere MaxEmerge or MaxEmerge Plus planter in connection with which the planter monitor system and method of the present invention may be used. It should be appreciated that although reference is made throughout this specification to row-crop planters and, in particular, certain models of John Deere planters, such references are simply examples to provide context and a frame of reference for the subject matter discussed. As such, the present planter monitor system and method should not be construed as being limited for use with any particular make or model of planter. Likewise, the present planter monitor system should not be construed as being limited to row-crop planters, since the features and functionalities of the monitor system may have application to grain drills or other planter types as well. [0024] The planter 10 includes a plurality of spaced row-units 12 supported along a toolbar 14 of the planter main frame 13 . The planter main frame 13 attaches to a tractor 15 in a conventional manner, such as by a drawbar 17 or three-point hitch arrangement as is well known in the art. Ground wheel assemblies (not shown) support the main frame 13 above the ground surface and are moveable relative to the main frame 13 through actuation of the planter's hydraulic system (not shown) coupled to the tractor's hydraulics to raise and lower the planter main frame 13 between a transport position and a planting position, respectively. [0025] As best illustrated in FIG. 3 , each row unit 12 is supported from the toolbar by a parallel linkage 16 which permits each row unit 12 to move vertically independently of the toolbar 14 and the other spaced row units in order to accommodate changes in terrain or upon the row unit encountering a rock or other obstruction as the planter is drawn through the field. Biasing means 18 , such as springs, air bags, hydraulic or pneumatic cylinders or the like, act on the parallel linkage 16 to exert a downforce on the row unit for purposes discussed in detail later. Each row unit 12 further includes a front mounting bracket 20 to which is mounted a hopper support beam 22 and a subframe 24 . The hopper support beam 22 supports a seed hopper 26 and a fertilizer hopper 28 as well as operably supporting a seed meter 30 and seed tube 32 . The subframe 24 operably supports a furrow opening assembly 34 and a furrow closing assembly 36 . [0026] In operation, the furrow opening assembly cuts a furrow 38 ( FIGS. 3 and 4 ) into the soil surface 40 as the planter is drawn through the field. The seed hopper 26 , which holds the seeds to be planted, communicates a constant supply of seeds 42 to the seed meter 30 . The seed meter 30 of each row unit 12 is typically coupled to the ground wheels through use of shafts, chains, sprockets, transfer cases, etc., as is well known in the art, such that individual seeds 42 are metered and discharged into the seed tube 32 at regularly spaced intervals based on the seed population desired and the speed at which the planter is drawn through the field. The seed 42 drops from the end of the seed tube 32 into the furrow 38 and the seeds 42 are covered with soil by the closing wheel assembly 36 . [0027] The furrow opening assembly 34 typically includes a pair of flat furrow opening disk blades 44 , 46 and a depth regulation assembly 47 . In the embodiment of FIGS. 2 and 3 , the depth regulation assembly 47 comprises a pair of gauge wheels 48 , 50 selectively vertically adjustable relative to the disk blades 44 , 46 by a height adjusting mechanism 49 . It should be appreciated, however, that instead of dual opening disks and dual gauge wheels as shown in the embodiment of FIGS. 2 and 3 , the planter 10 may utilize any other suitable furrow opener and depth regulation assembly suitable for cutting a furrow in the soil and regulating or controlling the depth of that furrow. [0028] In the planter embodiment of FIGS. 2 and 3 , the disk blades 44 , 46 are rotatably supported on a shaft 52 mounted to a shank 54 depending from the subframe 24 . The disk blades 44 , 46 are canted such that the outer peripheries of the disks come in close contact at the point of entry 56 into the soil and diverge outwardly and upwardly away from the direction of travel of the planter as indicated by the arrow 58 . Thus, as the planter 10 is drawn through the field, the furrow opening disks 44 , 46 cut a V-shaped furrow 38 through the soil surface 40 as previously described. [0029] As best illustrated in FIGS. 3 and 5 , gauge wheel arms 60 , 62 pivotally support the gauge wheels 48 , 50 from the subframe 24 about a first axis 61 . The gauge wheels 48 , 50 are rotatably mounted to the forwardly extending gauge wheel arms 60 , 62 at a second axis 63 . The gauge wheels 48 , 50 are slightly larger in diameter than the disk blades 44 , 46 such that the outer peripheries of the disk blades rotate at a slightly greater velocity than the gauge wheel peripheries. Each of the gauge wheels 48 , 50 includes a flexible lip 64 ( FIG. 4 ) at its interior face which contacts the outer face of the respective disk blade 44 , 46 at the area 66 ( FIG. 3 ) where the disk blades exit the soil. It should be appreciated that as the opening disks 44 , 46 exit the soil after slicing the V-shaped furrow 38 , the soil, particularly in wet conditions, will tend to adhere to the disk, which, if not prevented, would cause the furrow walls to be torn away as the disk rotates out of the soil causing poor furrow formation and/or collapse of the furrow walls, resulting in irregular seed planting depth. Thus, as best illustrated in FIGS. 3 and 4 , to prevent the furrow walls from tearing away as the disk blades exit the soil, the gauge wheels 48 , 50 are positioned to compact the strip of soil adjacent to the furrow while at the same time serving to scrape against the outer face of the disks 44 , 46 to shear off any soil buildup as the disks exit the soil. Accordingly, the opening disks 44 , 46 and the gauge wheels 48 , 50 cooperate to firm and form uniform furrow walls at the desired depth. [0030] In the planter embodiment of FIGS. 2 and 3 , the depth adjustment mechanism 67 which is used to vary the depth of the seed furrow 38 is accomplished through the vertical adjustment of the gauge wheels 48 , 50 relative to the furrow opening disk blades 44 , 46 by selective positioning of a height adjustment arm 68 . In this embodiment, a height adjusting arm 68 is pivotally supported from the subframe 24 by a pin 70 ( FIGS. 3 and 5 ). An upper end 72 of the height adjusting arm 68 is selectively positionable along the subframe 24 . As best illustrated in FIG. 5 , a rocker 76 is loosely pinned to the lower end 74 of the height adjusting arm 68 by a pin or bolt 78 . The rocker 76 bears against the upper surfaces of the pivotable gauge wheel arms 60 , 62 , thereby serving as a stop to prevent the gauge wheel arms 60 , 62 from pivoting counterclockwise about the first pivot axis 61 as indicated by arrow 82 . Thus, it should be appreciated that as the upper end 72 of the height adjusting arm 68 is selectively positioned, the position of the rocker/stop 76 will move accordingly relative to the gauge wheel arms 60 , 62 . For example, referring to FIG. 5 , as the upper end 72 of the height adjusting arm 68 is moved in the direction indicated by arrow 84 , the position of the rocker/stop 76 will move upwardly away from the gauge wheel arms 60 , 62 , allowing the gauge wheels 48 , 50 to move vertically upwardly relative to the furrow opening disk blades 44 , 46 such that more of the disk blade will extend below the bottom of the gauge wheels 48 , 50 , thereby permitting the furrow opening disk blades 44 , 46 to penetrate further into the soil. Likewise, if the upper end 72 of the height adjusting arm 68 is moved in the direction indicated by arrow 86 , the rocker/stop 76 will move downwardly toward the gauge wheel arms 60 , 62 , causing the gauge wheels 48 , 50 to move vertically downwardly relative to the furrow opening disk blades 44 , 46 , thereby shortening the penetration depth of the disk blades into the soil. When planting row crops such as corn and soybeans, the position of the rocker/stop 76 is usually set such that the furrow opening disk blades 44 , 46 extend below the bottom of the gauge wheels 48 , 50 to create a furrow depth between one to three inches. [0031] In addition to serving as a stop as previously described, the loosely pinned rocker 76 serves the dual function of “equalizing” or distributing the load carried by the two gauge wheels 48 , 50 , thereby resulting in more uniform furrow depth. It should be appreciated that during planting operations, substantially the entire live and dead load of the row unit 12 along with the supplemental downforce exerted by the biasing means 18 will be carried by the gauge wheels 48 , 50 after the opening disks 44 , 46 penetrate the soil to the depth where the gauge wheel arms 60 , 62 encounter the pre-selected stop position of the rocker 76 . This load is transferred by the pin 78 through the rocker 76 to the gauge wheel arms 60 , 62 . Because the rocker 76 is loosely pinned to the height adjusting arm 68 , the row unit load is distributed substantially equally between the two gauge wheel arms 60 , 62 such that one-half of the load is carried by each arm 60 , 62 . Thus, for example, if gauge wheel 48 encounters an obstruction such as a rock or hard soil clod, the gauge wheel arm 60 will be forced upwardly as the gauge wheel 48 rides up and over the obstruction. Since the rocker 76 is connected to the height adjusting arm 68 by the pin 78 , the rocker 76 will pivot about pin 78 causing an equal but opposite downward force on the other arm 62 . As such, the rocker 76 equalizes or distributes the load between the two gauge wheels. If there was no rocker such that lower end 74 of the height adjusting arm 68 was simply a bearing surface, upon one of the gauge wheels encountering an obstruction or uneven terrain, the entire load of the row unit 12 would be carried by that single gauge wheel as it rides up and over the obstruction or until the terrain was again level. Again, as previously stated, the specific reference to the foregoing components describing the type of furrow opening assembly, depth regulation member, seed meter, etc., may vary depending on the type of planter. [0032] There are various types of commercially available seed meters 30 which can generally be divided into two categories on the basis of the seed selection mechanism employed, namely, mechanical or pneumatic. The most common commercially available mechanical meters include finger-pickup meters such as disclosed in U.S. Pat. No. 3,552,601 to Hansen (“Hansen '601”), cavity-disc meters such as disclosed in U.S. Pat. No. 5,720,233 to Lodico et al. (“Lodico “233”), and belt meters such as disclosed in U.S. Pat. No. 5,992,338 to Romans (“Romans '338”), each of which is incorporated herein in its entirety by reference. The most common commercially available pneumatic meters include vacuum-disc meters such as disclosed in U.S. Pat. No. 3,990,606 to Gugenhan (“Gugenhan '606”) and in U.S. Pat. No. 5,170,909 to Lundie et al. (“Lundie '909”) and positive-air meters such as disclosed in U.S. Pat. No. 4,450,979 to Deckler (“Deckler '979”), each of which is also incorporated herein in its entirety by reference. The planter monitor system and method of the present invention should not be construed as being limited for use in connection with any particular type of seed meter. [0033] The GPS unit 100 , such as a Deluo PMB-288 available from Deluo, LLC, 10084 NW 53rd Street, Sunrise, Fla. 33351, or other suitable device, is used to monitor the speed and the distances traveled by the planter 10 . As will be discussed in more detail later, preferably the output of the GPS unit 100 , including the planter speed and distances traveled by the planter, is communicated to the monitor 1000 for display to the planter operator and/or for use in various algorithms for deriving relevant data used in connection with the preferred system and method of the present invention. [0034] As best illustrated in FIGS. 1 and 3 , the preferred planter monitor system 1000 preferably utilizes the existing seed sensors 200 and associated wiring harness 202 typically found on virtually all conventional planters 10 . The most common or prevalent type of seed sensors are photoelectric sensors, such as manufactured by Dickey-John Corporation, 5200 Dickey-John Road, Auburn, Ill. 62615. A typical photoelectric sensor generally includes a light source element and a light receiving element disposed over apertures in the forward and rearward walls of the seed tube. In operation, whenever a seed passes between the light source and the light receiver, the passing seed interrupts the light beam causing the sensor 200 to generate an electrical signal indicating the detection of the passing seed. The generated electrical signals are communicated to the monitor 1000 via the wiring harness 202 or by a suitable wireless communication means. It should be appreciated that any other type of seed sensors capable of producing an electrical signal to designate the passing of a seed may be equally or better suited for use in connection with the system and method of the present invention. Therefore the present invention should not be construed as being limited to any particular type of seed sensor. [0035] As previously identified, the preferred planter monitor system 1000 also utilizes load sensor 300 disposed to generate load signals corresponding to the loading experienced by or exerted on the depth regulation member 47 . The load sensor 300 and associated processing circuitry may comprise any suitable components for detecting such loading conditions, including for example, the sensors and circuitry as disclosed in PCT/US08/50427, previously incorporated herein in its entirety by reference. As discussed in more detail later, the loading experienced by or exerted on the gauge wheels 48 , 50 or whatever other depth regulating member is being used, is preferably one of the values displayed to the operator on the screen of the visual display 1002 and may also be used in connection with the preferred system and method to report the occurrence of yield robbing events (i.e., loss of furrow depth or excess soil compaction) and/or for automated adjustment of the supplemental downforce, if supported by the planter. [0036] An inclinometer 400 is preferably mounted to the front mounting bracket 20 of at least one row unit 12 of the planter 10 in order to detect the angle of the row unit 12 with respect to vertical. Because the row unit 12 is connected by a parallel linkage 16 to the transverse toolbar 14 comprising a part of the planter frame 13 , the angle of the front bracket 20 with respect to vertical will substantially correspond to the angle of the frame and toolbar 13 , 14 . It should be appreciated that if the planter drawbar is substantially horizontal, the front bracket 20 will be substantially vertical. Thus, if the drawbar is not level, the front bracket will not be substantially vertical, thereby causing the row units to be inclined. If the row unit is inclined, the furrow opening assembly 36 will cut either a deeper or more shallow furrow then as set by the depth adjustment mechanism 67 thereby resulting in poor germination and seedling growth. As such, data from the inclinometer 400 may be used in connection with the preferred system and method to detect and/or report potential yield robbing events and/or for automatic adjustment of the planter, if so equipped, to produce the necessary correction to level the row unit. For example, if the inclinometer 400 detects that the front bracket is not substantially vertical, it may initiate an alarm condition to advise the operator that the tongue is not level, the potential affects on seed placement, and will preferably display on the monitor screen 1002 the appropriate corrective action to take. [0037] As previously identified, the preferred planter monitor system 1000 also preferably includes a vertical accelerometer 500 and a horizontal accelerometer 600 . Preferably the vertical accelerometer 500 and horizontal accelerometer 600 are part of a single device along with the inclinometer 400 . [0038] The vertical accelerometer 500 measures the vertical velocity of the row unit 12 as the planter traverses the field, thereby providing data as to how smoothly the row unit is riding over the soil, which is important because the smoothness of the ride of the row unit can affect seed spacing. For example, if a seed is discharged from the seed meter just as the row unit encounters an obstruction, such as a rock, the row unit will be forced upwardly, causing the seed to have a slight upward vertical velocity. As the row unit passes over the obstruction, and is forced back downwardly by the biasing means 18 , or if the row unit enters a depression, a subsequent seed being discharged by the seed meter 30 will have a slight downward vertical velocity. Thus, all other factors being equal, the second seed with the initial downwardly imparted velocity will reach the ground surface in less time than the first seed have the initial upwardly imparted velocity, thereby affecting seed spacing. As such, data from the vertical accelerometer 500 may also be used in connection with the preferred system and method to identify and/or report seed placement yield robbing events resulting from rough field conditions, excessive planter speed and/or inadequate downforce exerted by the biasing means 18 . This information may be used to diagnose planter performance for automatic adjustment and/or providing recommendations to the operator pursuant to the preferred system and method of the present invention for taking corrective action, including, for example, increasing down force to reduce vertical velocities or reducing tractor/planter speed. [0039] The horizontal accelerometer 600 , like the inclinometer 400 provides data that may be used in connection with the preferred method to diagnose planter performance and/or for providing recommendations to the operator pursuant to the preferred system and method of the present invention for taking corrective action. For example, horizontal accelerations are known to increase as the bushings of the parallel linkage 16 wear. Thus, if the ratio of the standard deviation of the horizontal acceleration over the standard deviation of the vertical acceleration increases, it is likely that the bushings or other load transferring members of the parallel linkage are worn and need to be replaced. [0040] Turning now to FIGS. 5-13 , FIG. 5 is an example the preferred Level 1 Screen for the planter monitor system 1000 ; FIGS. 6-8 are examples of preferred Level 2 Screens; FIGS. 9-10 are examples of preferred Level 3 Screens; FIG. 11 is an example of a preferred Setup screen; and FIGS. 12-13 are examples of preferred Level 4 screens. Each of the screens is discussed below. Level 1 Screen (FIG. 5) [0041] The Level 1 Screen 1010 is so named because it is preferably the default screen that will be displayed on the monitor display 1012 unless the operator selects a different screen level to view as discussed later. The preferred Level 1 Screen 1010 includes a plurality of windows corresponding to different planter performance details, including a Seed Population Window 1012 , a Singulation Window 1014 , a Skips/Multiples Window 1016 , a Good Spacing Window 1018 , a Smooth Ride Window 1020 , a Speed Window 1022 , a Vacuum Window 1024 (when applicable), a Downforce Window 1028 and an Economic Loss Window 1028 . Each of these windows and the method of deriving the values displayed therein are discussed below. In addition the Level 1 Screen 1010 preferably includes various function buttons, including a Setup button 1030 , a Row Details button 1032 , a SnapShot button 1034 and a Back button 1036 , each of which is discussed later. [0042] Population Window 1012 : The Population Window 1012 preferably includes a numeric seed population value 1100 , preferably updated every second (i.e., 1 Hz cycles), representing the running average of the number of seeds (in thousands) being planted per acre over a predefined sampling frequency, preferably 1 Hz. This seed population value 1100 is based on the following formula: [0000] Seed   population   1030 = 0.001 × SeedCount Rows × Spacing  ( ft ) × Dist  ( ft ) × 43500   ft 2  /  acre Where  : Seedcount = Total   number   of   seeds   detected   by   Sensors   200   in   all   rows   during   sample   frequency .  Rows = Number   of   planter   rows   designated   during   Setup   ( discussed   later ) Spacing = Planter   row   spacing   designated   during   Setup Dist = Distance   ( ft )   traveled   by   planter   based   on   input   from   GPS   unit   100   during   the   sample   frequency [0043] Thus, for example, assuming the seed sensors 200 detect a total of 240 seeds over the preferred 1 Hz cycle, and assuming the planter is a sixteen row planter with thirty inch rows (i.e., 2.5 ft) and the average speed of the planter is six miles per hour (i.e. 8.8 ft/sec) during the 1 Hz cycle, the seed population would be: [0000] Seed   population  =  0.001 × 240 ( 16 × 2.5   ft × 8.8   ft ) × 43500   ft 2  /  acre =  29.6 [0044] In the preferred embodiment, however, although the seed population value 1100 is updated or re-published every second, the actual seed population is not based on a single one-second seed count. Instead, in the preferred embodiment, the seeds 9 detected over the previous one second are added to a larger pool of accumulated one-second seed counts from the preceding ten seconds. Each time a new one-second seed count is added, the oldest one-second seed count is dropped from the pool and the average seed population is recalculated based on the newest data, this recalculated average is then published every second in the Seed Population Window 1012 . [0045] In addition to identifying the seed population value 1100 as just identified, the preferred Seed Population Window 1012 also preferably displays a graph 1102 for graphical representation of the calculated average seed population 1100 relative to the target population 1338 ( FIG. 11 ) (specified during Setup as discussed later) designated by a hash mark 1104 . Corresponding hash marks 1106 , 1108 represent the population deviation limits 1342 ( FIG. 11 ) (also specified during Setup as discussed later). An indicator 1110 , such as a large diamond, for example, is used to represent the calculated average population. Other distinguishable indicators 1112 , such as smaller diamonds, represent the corresponding population rate of the individual rows relative to the target hash mark 1104 . Additionally, the Seed Population window 1012 also preferably identifies, by row number, the lowest population row 1114 (i.e., the planter row that is planting at the lowest population rate, which, in the example in FIG. 5 is row 23 ) and the highest population row 1116 (i.e., the planter row that is planting at the highest population rate, which, in the example in FIG. 5 is row 19 ) along with their respective population rates 1118 , 1120 . [0046] In the preferred system and method, the monitor preferably provides some sort of visual or audible alarm to alert the operator of the occurrence of any yield robbing events related to population. Preferably, if the yield robbing event concerns population, only the Population Window 1012 will indicate an alarm condition. An alarm condition related to population may include, for example, the occurrence of the calculated seed population value 1100 falling outside of the population deviation limits 1342 specified during setup. Another alarm condition may occur when the population of any row is less than 80% of the target population 1338 . Another alarm condition related to population may include the occurrence of one or more rows falling outside the population deviation limits for a predefined time period or sampling frequency, for example five consecutive 1 Hz cycles, even though an average population of those rows is in excess 80% of the target population 1338 . Yet another alarm condition may occur when there is a “row failure” which may be deemed to occur if the sensor 200 fails to detect the passing of any seeds for a specified time period, such as four times T presumed (discussed below). [0047] As previously identified, upon the occurrence of any of the foregoing alarm conditions, or any other alarm condition as may be defined and programmed into the monitor system 1000 , the Population window 1012 preferably provides a visual or audible alarm to alert the operator of the occurrence of the alarm condition. For example, in the preferred embodiment, if the calculated seed population value 1100 is within the specified population deviation 1342 (e.g., 1000 seeds) of the target population 1338 (e.g., 31200 seeds), the background of the Population Window 1012 is preferably green. If, however, the calculated seed population value 1100 falls below the target population 1338 by more than the specified population deviation, the Population Window 1012 preferably turns yellow. Alternatively, the Population Window 1012 may flash or provide some other visual or audible alarm under other alarm conditions. Obviously, many different alarm conditions can be defined and many different visual and/or audible indications of an alarm condition may be programmed into the monitor system 1000 as recognized by those of skill in the art. [0048] Furthermore, in the preferred embodiment, the touch screen GUI 1004 of the monitor system 1000 allows the operator to select different areas of the Population Window 1012 which will cause the monitor to display additional relevant detail related to the feature selected. For example, if the operator touches the calculated seed population value 1100 , the screen changes to display the Level 2 Population Details screen ( FIG. 6 ). If the operator touches the area of the screen in the Population Window 1012 in which the low population row 1114 is displayed, the screen changes to the Row Details screen ( FIG. 9 ) which displays the details of that specific row. Similarly, if the operator touches the area of the screen in the Population Window 1012 in which the high population row 1116 is displayed, the screen changes to the Row Details screen ( FIG. 9 ) which displays the details of that specific row. [0049] Singulation Window 1014 : The Singulation Window 1014 preferably includes a numeric percent singulation value 1122 , preferably published at 1 Hz cycles, representing the running average of the percentage singulation over the predefined sampling frequency, preferably 2 kHz (0.5 msec). In order to determine the percent singulation value 1122 it is first necessary to identify the skips and multiples occurring during the sampling period. Once the number of skips and multiples within the sampling period is known in relation to the number of “good” seeds (i.e., properly singulated seeds), then the percent singulation value 1100 can be calculated as identified later. [0050] The preferred system and method includes a criteria for distinguishing when a skip or a multiple occurs. In the preferred system and method, every signal generated by the sensor 200 is classified into one of six classifications, i.e., “good”, “skip”, “multiple”, “misplaced2”, “misplaced4”, and “non-seed”. A “good” seed is recorded when a signal is generated within a predefined time window when the signal was expected to have occurred based on planter speed and set target population which together define the presumed time interval (T presumed ). A “skip” is recorded when the time between the preceding signal and the next signal is greater than or equal to 1.65 T presumed . A “multiple” is recorded when the time between the preceding signal and the next signal is less than or equal to 0.35 T presumed . In order to accurately distinguish between metering errors resulting in true skips and true multiples as opposed to the seeds simply being misplaced due to placement errors resulting after discharge by the seed meter (i.e, ricochet, differences in vertical acceleration, etc.), the initial classifications are preferably validated before being recorded as skips or multiples. To validate the initial classifications, the monitor is programmed to compare changes in the average value for the last five time intervals relative to the average for the last twenty time intervals (T 20 Avg ). In the preferred system, if the 5-seed interval average (T 5 Avg ) is more than 1.15 T 20 Avg for more than three consecutive calculations, then the original classification of a skip is validated and recorded as a true skip. If T 5 Avg is less than 0.85 T 20 Avg for more than three consecutive calculations, then the original classification of a multiple is validated and recorded as a true multiple. If the foregoing limits are not exceeded, then the originally classified skip is reclassified as “good,” and the originally classified multiple is reclassified as a “misplaced” seed. Thus, by validating the original classifications, metering errors are distinguished from placement errors, thereby providing the operator with more accurate information as to the planter operation and the occurrence of yield robbing events. [0051] The “misplaced2” classification refers to a seed that is within two inches of an adjacent seed. Before a seed is recorded as a “misplaced2” the average spacing is calculated based on population and row spacing. A time threshold (T 2 threshold ) is calculated to classify “misplaced2” seeds by the equation: [0000] T 2 threshold =T presumed ×(2÷average spacing (inches)). [0052] The “misplaced 4 ” classification refers to a seed that is within four inches of an adjacent seed. A time threshold (T 4 threshold ) is calculated to classify “misplaced4” seeds by the equation: [0000] T 4 threshold =T presumed ×(4÷average spacing (inches)). [0053] Thus, a seed is classified as a misplaced4 seed when the time interval between the preceding signal and the next signal is greater than the T 2 threshold but less than T 4 threshold . [0054] In order to account for occasional instances when a train of dust or other debris cascades through the seed tube resulting in a rapid generation of signal pulses, the monitor system preferably classifies the entire series of rapid signal pulses as “non-seed” occurrences (even though seeds were still passing through the tube along with the train of dust or debris) rather then recording the rapid signal pulses as a string of multiples or misplaced seeds. However, in order to maintain a relatively accurate seed count and relatively accurate singulation percentage, the monitor system is preferably programmed to fill in the number of seeds that passed through (or should have passed through) the seed tube along with the cascade of dust and debris. Thus, in a preferred embodiment, when there are more than two pulses in series with an interval of less than 0.85 T presumed , all the signal pulses detected after that occurrence are classified as non-seeds until there is an interval detected that is greater than 0.85 T presumed . Any signal pulse classifying as a non-seed is not taken into account in any calculations for determining percent singulation values 1122 . In the preferred embodiment, in order to maintain correct population values 1100 when the interval is less than 0.85 T presumed , the interval is measured from the last “good” seed occurrence prior to the rapid signal event that produced the “non-seed” classification until the first “good” seed classification. The accumulated seed value is corrected or adjusted by adding to the count of “good” seeds the number of occurrences corresponding to the number of times T presumed can be divided into non-seed classification time period leaving no remainder greater than 1.85 T presumed . [0055] It should be appreciated, that because T presumed will vary with planter speed, which continually changes during the planting operation as the planter slows down or speeds up based on field conditions (i.e., hilly terrain, when turning or when approaching the end of the field, etc.), T presumed is a dynamic or continuously changing number. One method of deriving T presumed is as follows: [0056] a) Determine average across all rows of previous 1 seed (T 1 Avg ) as follows: 1) For each row, store the time interval from the last seed. Sort from minimum to maximum 2) Calculate the average time interval across all rows 3) If the ratio of the smallest interval divided by the average interval from step 2 is ≦0.75, then remove lowest number and repeat step 2. 4) If the ratio of the maximum interval divided by the average interval is ≧1.25, then remove maximum interval and repeat step 2. 5) T 1 Avg is the average time interval across all rows where the ratio of smallest time interval divided by the average time interval is ≧0.75 and ratio of the maximum interval divided by the average interval is ≦1.25. [0062] b) Determine average time interval across all rows of previous 5 seeds (T 5 Avg ) as follows: 1) For each row, store the time intervals of last five seeds in circular buffer; exclude intervals where the time interval to the next seed is less than 0.5 T 1 Avg or greater than 1.5 T 1 Avg . 2) Calculate the row average (i.e., the average time interval for each row) by dividing the sum of the stored time intervals from step 1 by the seed count from step 1. 3) Determine the row ratio. if the time interval since the last seed is ≦1.5× row average, then row ratio=1 if the time interval since the last seed is >1.5× row average, then row ratio=(1−(last time interval÷(row average×5))) 4) For each row, multiply the row ratio by the row average and sum the products. 5) Calculate T 5 Avg by dividing the value from step 4 by the sum of the row ratios. [0070] c) Determine average time interval across all rows of previous 20 seeds (T 20 Avg ) 1) For each row, store the time intervals of last 20 seeds in circular buffer; exclude intervals where the time interval to the next seed is less than 0.5 T 1 Avg or greater than 1.5 T 1 Avg . 2) Calculate the row average (i.e., the average time interval for each row) by dividing the sum of the stored time intervals from step 1 by the seed count from step 1. 4) Determine the row ratio. if the time interval since the last seed is ≦1.5× row average, then row ratio=1 if the time interval since the last seed is >1.5× row average, then row ratio=(1−(last time interval÷(row average×20))) 5) Calculate T 20 Avg by dividing the value from step 4 by the sum of the row ratios. [0077] d) Determine T presumed : 1) If all values have been filtered out, then T presumed =T 1 Avg . 2) Else, if T 20 Avg ≧1.1×T 5 Avg and T 20 Avg ≧T 1 Avg , then T presumed =T 5 Avg . 3) Else, if T 20 Avg ≦0.9×T 5 Avg and T 20 Avg ≦T 1 Avg , then T presumed =T 5 Avg . 4) Else, T presumed =T 20 Avg . [0082] Obviously other methods of deriving T presumed may be equally suitable and therefore the present invention should not be construed as being limited to the foregoing method for deriving T presumed . [0083] The percentage of skips (% Skips) 1124 can be determined by adding the total number of skips detected across all rows over a predefined seed count (preferably the Averaged Seed value 1302 specified during Setup (default is 300 seeds)) and then dividing the total number of skips by that seed count. Similarly, the percentage of multiples (% Mults) 1126 can be determined by adding the total number of multiples detected across all rows over the same predefined seed count and then dividing the total number of multiples by the predefined seed count. The percent singulation value 1122 may then be calculated by adding the % Skips 1124 and % Mults 1126 and subtracting that sum from 100%. [0084] In addition to displaying the percent singulation value 1122 , the Singulation Window 1014 also preferably displays a graph 1128 for graphically representing the numeric percentage singulation 1122 relative to the 100% singulation target. The graph 1128 also preferably displays hash marks 1130 incrementally spaced across the graph 1128 corresponding to the Singulation Deviation limits 1350 ( FIG. 11 ) specified during setup. An indicator 1132 , such as a large diamond, preferably identifies the percent singulation value 1122 relative to the 100% singulation target. Other distinguishable indicators 1134 , such as smaller diamonds, preferably indicated the corresponding singulation percentages of the individual rows relative to the 100% singulation target. Additionally, the Singulation Window 1014 also preferably identifies numerically the planter row that is planting at the lowest singulation percentage 1136 (which in the example in FIG. 5 is row 23 ) along with the percent singulation value 1138 for that row. [0085] Similar to the Population Window 1012 previously discussed, the Singulation Window 1014 preferably provides some sort of visual or audible alarm to alert the operator of the occurrence of any yield robbing events related to singulation. An alarm condition related to singulation may include, for example, the occurrence of the percent singulation value 1122 falling outside of the singulation deviation limits 1350 specified during setup. Another alarm condition may include, for example, when an average percent singulation of two or more rows exceeds the singulation deviation limits 1350 for five consecutive 1 Hz calculations, for example. Another alarm condition may include, when one row exceeds the singulation deviation limits 1350 by more than two times for five consecutive 1 Hz calculations, for example. As before, many different alarm conditions can be defined and many different visual and/or audible indications of an alarm condition may be programmed into the monitor system 1000 to cause the Singulation Window 1014 to provide the operator with visual or audible alarms to indicate the occurrence of a yield robbing event related to singulation. All such variations in alarm conditions and alarm indications are deemed to be within the scope of the present invention. [0086] Furthermore, in the preferred embodiment, the preferred touch screen GUI 1004 of the monitor system 1000 allows the operator to select different areas of the Singulation Window 1014 which will cause the monitor to display additional relevant detail related to the feature selected. For example, if the operator touches the calculated percent singulation value 1122 , the screen changes to display the Level 2 Singulation Details screen ( FIG. 7 ). If the operator touches the area of the screen in the Singulation Window 1014 in which the low singulation row 1136 is displayed, the screen changes to the Row Details screen ( FIG. 9 ) which displays the details of that specific row. [0087] Skips/Mults Window 1016 : The Skips/Mults Window 1016 preferably displays the value of the calculated % Skips 1124 and % Mults 1126 as previously identified. As with the other Windows previously described, the Skips/Mults Window 1016 may provide some sort of visual or audible alarm to alert the operator if the % Skips or % Mults exceed predefined limits. [0088] Good Spacing Window 1018 : The Good Spacing Window 1018 preferably includes a numeric percent good spacing value 1140 representing the running average percentage of “good” seed spacing versus “misplaced” seeds, i.e., the number of seeds categorized as “misplaced2” or “misplaced4” (as previously defined) over the predefined sampling frequency (preferably 0.1 Hz). Once the number of misplaced2 and misplaced4 seeds are known in relation to the number of seeds during the sample period, then the percentage of misplaced2 seeds (% MP2) and the percent misplaced4 seeds (% MP4) relative to good spaced seeds is readily ascertained. Likewise, the percent good spacing value 1140 is readily ascertained by subtracting the sum of % MP2 and % MP4 from 100%. [0089] In addition to displaying the calculated percent good spacing value 1140 , the Good Spacing Window 1018 also preferably includes a graph 1142 for graphically representing the percent good spacing value 1140 relative to the 100% good spacing target. Hash marks 1144 are preferably provided to identify a scale from 80% to 100% at 5% increments. An indicator 1146 , such as a large diamond, preferably identifies the calculated good spacing value 1140 relative to the 100% good spacing target. Other distinguishable indicators 1148 , such as smaller diamonds, preferably identify the corresponding good spacing percentages of the individual rows relative to the 100% goods spacing target. Additionally, the Good Spacing Window 1018 also preferably identifies numerically the planter row that is planting at the lowest good spacing percentage 1150 (which in the example in FIG. 5 is row 9 ) along with the numerical percent good spacing value 1152 for that row. [0090] Similar to the other Windows 1012 , 1014 the Good Spacing Window 1018 preferably provides some sort of visual or audible alarm to alert the operator of the occurrence of any yield robbing events related to spacing. An alarm condition related to spacing may include, for example, if the overall percent good spacing value 1140 or row specific spacing value falls below a predetermined deviation limit, such as 90%. Many different alarm conditions can be defined and many different visual and/or audible indications of an alarm condition may be programmed into the monitor system 1000 to cause the Good Spacing Window 1018 to provide the operator with visual or audible alarms similar to those described with the other Windows 1012 , 1014 to indicate the occurrence of a yield robbing event related to spacing. All such variations in alarm conditions and alarm indications are deemed to be within the scope of the present invention. [0091] In the preferred embodiment, the touch screen GUI 1004 of the monitor system 1000 allows the operator to select different areas of the Good Spacing Window 1018 which will cause the monitor to display additional relevant detail related to the feature selected. For example, if the operator touches the calculated percent good spacing value 1140 , the screen changes to display the Level 2 Placement Details screen ( FIG. 8 ). If the operator touches the area of the screen in the Good Spacing Window 1018 in which the low row 1150 is displayed, the screen changes to the Row Details screen ( FIG. 9 ) which displays the details of that specific row. [0092] Smooth Ride Window 1020 : The Smooth Ride Window 1020 preferably displays the smooth ride percentage value 1154 . The smoothness of the ride is estimated based on the percentage of time the vertical velocity of the row unit is less than a predefined vertical velocity limit (VVL). In the preferred embodiment, the VVL is four inches per second (4 in/sec). This VVL was selected based on empirical data which established that seed spacing was measurably affected when the row unit was subjected to vertical velocities above 4 in/sec. [0093] The number of times the vertical velocity of the row unit 12 on which the sensor 500 is mounted exceeds the VVL is counted over a predefined time period (preferably 30 seconds). The percentage of time during the predefined time period that the VVL was exceeded is then calculated for each sensor 500 and then an average is calculated (Ave % T>VVL). The smooth ride percentage value 1154 is then calculated by subtracting the value of Ave % T>VVL from 100%. [0094] In addition to displaying the calculated smooth ride percentage value 1154 , the Smooth Ride Window 1020 also preferably displays a graph 1156 to graphically represent the smooth ride percentage value 1154 relative to the 100% smooth ride target. Incremental hash marks 1158 preferably identify a scale, such as at 85%, 90% and 95%, across a predefined range, preferably from a low of 80% smooth ride to 100% smooth ride. An indicator 1160 , such as a large diamond, preferably identifies the calculated smooth ride percentage value 1154 relative to the 100% smooth ride target. Other distinguishable indicators 1162 , such as smaller diamonds, preferably identify the corresponding smooth ride percentages of the individual rows relative to the 100% smooth ride target. Additionally, the Smooth Ride Window 1020 also preferably identifies numerically the planter row that is planting at the lowest smooth ride percentage 1164 (which, in the example in FIG. 5 is row 14 ) along with the numerical smooth ride percentage value 1166 for that row. [0095] As with the other Windows 1012 , 1014 , 1018 the Smooth Ride Window 1020 preferably provides some sort of visual or audible alarm to alert the operator of the occurrence of any yield robbing events related to the smoothness of the ride. An alarm condition related to ride smoothness may include, for example, if the overall smooth ride percentage 1154 or any row specific smooth ride percentage falls below a predetermined deviation limit, such as 90%. Also as with the other Windows, many different alarm conditions can be defined and many different visual and/or audible indications of an alarm condition may be programmed into the monitor system 1000 to cause the Smooth Ride window 1020 to provide the operator with visual or audible alarms to indicate the occurrence of a yield robbing event related to ride smoothness. All such variations in alarm conditions and alarm indications are deemed to be within the scope of the present invention. [0096] Speed Window 1022 : The Speed Window 1022 preferably displays the velocity 1168 of the planter in miles per hour (mph). In the preferred embodiment, the velocity 1168 is preferably averaged over the last five seconds of data collected by the GPS unit 100 unless the planter acceleration (ΔVI/Δt) is greater than 1 mph/sec, in which event, the velocity 1168 is preferably displayed as the actual velocity collected by the GPS unit 100 . [0097] As with the other Windows previously described, the Speed Window 1022 may provide some sort of visual or audible alarm to alert the operator if the speed falls below or exceeds predefined limits. Additionally, if the processing circuitry is programmed to diagnose planter performance and to logically identify if speed is a contributing factor to a low smooth ride percentage 1154 or low good spacing value 1140 , for example, an alarm condition may be triggered producing a visual or audible indication as previously described in connection with the other Windows. [0098] Vacuum Window 1024 : The Vacuum Window 1024 preferably displays the vacuum value 1170 in inches of water (in H 2 O). If the type of meter selected during setup was other than “vacuum” the Vacuum Window 1024 is preferably blank or not displayed. If “vacuum” was selected during setup, but no vacuum sensor 700 is connected to the monitor 1000 or data from the vacuum sensor 700 is otherwise not being communicated to the monitor 1000 , the Vacuum Window 1024 may show a zero vacuum value, or the window may be blank or not displayed. [0099] As with the other Windows previously described, the Vacuum Window 1024 may provide some sort of visual or audible alarm to alert the operator if the vacuum falls below or exceeds predefined limits. Additionally, if the processing circuitry is programmed to diagnose planter performance and to logically identify if the vacuum is a contributing factor to a low singulation percentage 1122 or poor spacing percentage 1140 , or excessive % Skips 1126 or % Mults 1124 , for example, an alarm condition may be triggered producing a visual or audible indication as previously described in connection with the other Windows. [0100] Downforce Window 1026 : The Downforce Window 1026 preferably displays a ground contact parameter 1172 (preferably as a percentage of ground contact over a predefined sampling period). The Downforce Window 1026 may also include an area for displaying the average downforce value 1174 and/or alternatively, or in addition, the Downforce window 1026 may display the “load margin” 1175 (not shown). The percent ground contact parameter 1172 is preferably derived as more fully explained in PCT/US08/50427, previously incorporated herein by reference. The average downforce value 1174 may be derived by averaging the detected load values over a predefined time period across all load sensors 300 on the planter. The load margin 1175 is preferably calculated and/or derived by any of the methods disclosed in PCT/US08/50427. The downforce value 1174 and/or load margin 1175 may also be displayed graphically as disclosed in PCT/US08/50427. [0101] As with the other Windows previously described, the Downforce Window 1026 may provide some sort of visual or audible alarm to alert the operator if the downforce, load margin, or the ground contact parameter exceeds or falls below predefined limits. Additionally, if the processing circuitry is programmed to diagnose planter performance and to logically identify if a low ground contact parameter and/or low or excessive downforce or load margin is a contributing factor to a low smooth ride percentage 1154 , for example, an alarm condition may be triggered producing a visual or audible indication as previously described in connection with the other Windows. [0102] Economic Loss Window 1028 : The Economic Loss Window 1028 preferably displays the economic loss value 1176 in dollars lost per acre ($Loss/acre) attributable to the various yield robbing events. The calculated economic loss value 1176 may be continually displayed or the value may only be displayed only upon an alarm condition, such as when the value exceeds a predefined value, such as, for example, $3.00/acre. If an alarm condition is not present, the Economic Loss Window 1028 may simply display the word “Good” or some other desired designation. [0103] In the preferred embodiment each occurrence of a yield robbing event is associated with an economic loss factor. In the preferred embodiment, the economic loss factor is an Ear Loss (EL) factor 1310 . For example, empirical data has shown that, when compared to a plant maturing from a seed properly spaced from adjacent seeds (typically six to seven inches for thirty inch rows at plant populations around 32000 seeds/acre), if a seed is misplaced such that it is only two inches from an adjacent seed (i.e., misplaced2), the net loss will be about 0.2 ears (i.e., EL=0.2). A misplaced seed that is only four inches from an adjacent seed (i.e., misplaced4) will have a net loss of about 0.1 ears (i.e., EL=0.1). A skip has been found to result in a net loss of 0.8 ears (EL=0.8). A double has been found to result in a net loss of 0.4 ears (EL=0.4). [0104] The foregoing EL factors assume that the grower is planting “flex” hybrids as opposed to “determinate” hybrids. Simply described, a flex hybrid is one where a plant will produce larger ears depending upon seed spacing due to less competition for sunlight and nutrients. Thus, for example, if there is a space larger than four inches between an adjacent plant in a row, a flex hybrid plant will presumably receive additional sunlight and more nutrients than seeds spaced at four inches or less, enabling it to produce a larger ear with more kernels. By contrast, a determinate hybrid will have the same ear size regardless of increased seed spacing. [0105] With the foregoing understanding, based on empirical data, the skip EL factor was derived by taking into account that although one ear has been lost due to the skip, the two adjacent plants on either side of the skip each increase their respective ear size by 10%. Thus, the net ear loss for a skip is only 0.8 ears instead of a whole ear (i.e., −1+0.1+0.1=−0.8). For a further example, if future hybrids have the ability to increase ear size by 50% on either side of a skip, then the net ear loss would approach zero as each adjacent plant has added 50%, thereby making up for the entire lost ear (i.e., −1+0.5+0.5=0.0). Thus, it should be understood that these EL factors may change over time as the characteristics of corn hybrids continue to evolve and improve. As such, in the preferred embodiment, the default EL factors may be varied by the operator. By associating an EL factor to each occurrence of a skip, multiple, misplaced2 and misplaced4 seed, an economic loss attributable to each of these yield robbing events over a sampling period can be determined. [0106] In addition to skips, multiples and misplaced seeds, the loss of ground contact and excessive downforce are also yield robbing events. Accordingly, in the preferred monitor system EL factors are also associated with each of these yield robbing events. [0107] The economic loss attributed to excessive downforce is preferably based on load margin 1175 as previously discussed in connection with the Downforce Window 1026 and as disclosed in PCT/US08/50427. In the preferred system, the following EL factors are applied based on the magnitude of the load margin: 1) If load margin<50 lbs, EL=0 2) If 50 lbs≦load margin≦100 lbs, EL=0.05 3) If 100 lbs≦load margin≦200 lbs, EL=0.1 4) If load margin>200 lbs=0.15 [0112] As disclosed in the PCT/US08/50427, the sampling period or frequency of detecting the load margin may vary. However, in the preferred monitor system of the present invention, the sampling period is preferably the same as the seed planting rate such that a load margin is calculated with respect to each seed. Accordingly, an EL factor based on load margin can be applied to each seed planted. With an EL factor assigned to the load margin for each seed planted, an average EL (i.e., EL Avg-Excess Load ) factor for a given sampling period may then be calculated. The EL Avg-Excess Load factor multiplied by the number of seeds in the sampling period may be used for determining the percentage of yield loss attributable to load margin during the sampling period as discussed below. [0113] As for the economic loss attributable to loss of ground contact, it should be appreciated that the longer the duration that the depth regulating member of the row unit is not in contact with the soil, the greater will be the loss in depth of the furrow. In the preferred system an EL factor of 0.5 is multiplied by the percentage of time during a sampling period that there has been loss of ground contact (% Contact Lost) to determine the percentage of yield loss attributable to loss of ground contact during the sampling period. The sampling period may be any desired time period, but in the preferred embodiment, the sampling period for this EL factor is preferably the time required to plant 300 seeds at the seed population specified during Setup. [0114] In order to provide an economic loss information in a format useful to the operator, the preferred embodiment displays the economic loss in dollars lost per acre (i.e., $Loss/Acre). However, it should be appreciated that the economic loss may be presented in any desired units. Under the preferred $Loss/Acre units, the economic loss may be calculated by multiplying the percentage of yield lost due to the yield robbing event by the projected yield and multiplying that product by the price of the grain. Accordingly, in the preferred embodiment, the $Loss/Acre may be calculated by the following formula: [0000] $Loss/Acre=% Yield Lost×Population×(Bushels/Ear)×(Price/Bushel) Where: % Yield Lost=Sum of all calculated yield losses attributable to all occurrences during the sampling period (e.g., 300 seeds) of skips, multiples, misplaced2, misplaced4, ground contact loss and load margin; i.e., 0.8(% Skips)+0.4(% Mults)+0.2(% MP2)+0.1(% MP4)+0.5(% Contact Loss)+EL Avg-Excess Load (300 seeds). Note, the foregoing EL factors may vary as set by the operator during Setup as previously described. Population=The target seed population specified during setup Bushels/Ear=Estimated number of ears required to produce one bushel of shelled corn (default=1 bu/140 ears); preferably configurable through Setup [0118] Price/Bushel=Estimated price of corn per bushel (default=$2.50/bu); preferably configurable through Setup [0119] As with the other Windows previously described, the Economic Loss Window 1028 may provide some sort of visual or audible alarm to alert the operator if the economic loss exceeds a predefined limit. Additionally, the Economic Loss Window 1028 may be associated or tied to the other Windows 1012 , 1014 , 1016 , 1018 , 1020 , 1022 , 1024 , 1026 such that if an alarm condition is met in any of these other Windows, and such alarm condition is found to be the contributing factor to the alarm condition in the Economic Loss Window, then both Windows produce a visual or audible indication of the alarm condition as previously described in connection with the other Windows. [0120] Setup button 1030 : Upon pressing the Setup button 1030 , the monitor 1000 is preferably programmed to display the Setup screen 1300 ( FIG. 11 ) through which the operator can make selections and/or input data via the preferred touch screen GUI 1004 . [0121] Row Details button 1032 : Upon pressing the Row Details button 1032 , the monitor is preferably programmed to display the Row Selection screen 1220 ( FIG. 10 ) through which the operator can select a Level 3 Screen (discussed later) for that particular row. [0122] SnapShot button 1034 : Upon pressing the Snapshot button 1034 , the monitor 1000 is preferably programmed to store all data inputs from the various sensors on a read/writable storage medium for a predefined time period, preferably ninety seconds, across all row units. The read/writable storage medium may be a magnetic data storage tape or disk, or a solid state semi-conductor memory storage device such as flash memory or a memory card, or the read/writable storage medium may be any type of remote computer or storage device to which data can be communicated by via a wired or wireless connection. The purpose of the SnapShot button 1034 will be described in detail later. [0123] Back button 1036 : The Back button 1036 changes the screen to the previously displayed screen. Level 2 Screens (FIGS. 6-8) [0124] Population Details Screen ( FIG. 6 ): FIG. 6 is an example of a preferred embodiment for displaying population details in a bar graph format for all rows of a planter. In the example of FIG. 6 , a bar graph 1200 of the population details for a 32 row planter is shown. The number of rows displayed for the bar graph 1200 may be dynamic based on the number of rows entered during Setup. Alternatively, the number of rows may remain fixed on the screen with data only being displayed for the number of rows entered during Setup. [0125] The horizontal line 1202 on the bar graph 1200 corresponds to the population target 1338 ( FIG. 11 ) entered during Setup and the vertical scale of the bar graph 1200 preferably corresponds to the deviation limit 1342 (e.g., ±1000 seeds) specified during Setup. The numeric population value 1112 for each row is graphically displayed as a data bar 1204 above or below the horizontal line 1202 depending on whether the numeric population value is greater then or less then the target population value 1338 , respectively. In the preferred embodiment, if a particular row approaches or exceeds the deviation limit 1342 , an alarm condition is triggered and the data bar 1204 for that row preferably includes a visual indication that it is in alarm condition. For example, in the preferred embodiment, the data bar 1204 for a row in an alarm condition is colored yellow (solid bars) whereas the data bars 1204 of the rows that are not in an alarm condition are green (clear bars). Alternatively, the data bars 1204 may flash under an alarm condition or change to a different color, such as red, under specific alarm conditions or depending on the severity of the yield robbing event. As with the different Level 1 Screens, there are various ways to represent an alarm condition, by different colors, audible alarms, etc. Accordingly, any and all means of visually or audibly indicating an alarm condition should be considered within the scope of this invention. [0126] In the preferred embodiment, the touch screen GUI 1004 preferably enables the operator to touch a bar 1204 for a particular row to change the screen to the Level 3 Screen display for that selected row. The up arrow button 1206 and down arrow button 1206 preferably enables the operator to scroll between the various Level 2 Screens ( FIGS. 6-8 ) as hereinafter described. The Back button 1036 changes to the previously displayed screen. The Home button 1209 returns to the Level 1 Screen ( FIG. 5 ). The Row Details button 1032 preferably displays the Row Selection screen ( FIG. 10 ). [0127] Singulation Details Screen ( FIG. 7 ): FIG. 7 is an example of a preferred embodiment for displaying singulation details in a bar graph format for all rows of a planter. In the example of FIG. 7 , a bar graph 1210 of the singulation details for a 32 row planter is shown. The number of rows displayed for the bar graph 1210 may be dynamic based on the number of rows entered during Setup. Alternatively, the number of rows may remain fixed on the screen with data only being displayed for the number of rows entered during Setup. [0128] The horizontal line 1212 on the bar graph 1210 corresponds to 100% singulation (i.e., zero multiples and zero skips) and the vertical scale of the bar graph 1210 preferably corresponds to the singulation deviation limit 1350 (e.g., 1% in FIG. 11 ) specified during Setup. The % Mults 1126 for a particular row are displayed as a data bar 1184 above the horizontal reference line 1212 . The % Skips 1124 for a particular row are displayed as a data bar 1214 below the horizontal reference line 1212 . In the preferred embodiment, if a particular row approaches or exceeds the singulation deviation limit 1350 , an alarm condition is triggered and the data bar 1214 for that row preferably includes a visual indication that it is in alarm condition. For example, in the preferred embodiment, the data bar 1214 for a row in an alarm condition is colored yellow (solid bars) whereas the data bars 1214 of the rows that are not in an alarm condition are green (clear bars). Alternatively, the data bars 1214 may flash under an alarm condition or change to a different color, such as red, under specific alarm conditions or depending on the severity of the yield robbing event. As with the different Level 1 Screens, there are various ways to represent an alarm condition, by different colors, audible alarms, etc. Accordingly, any and all means of visually or audibly indicating an alarm condition should be considered within the scope of this invention. [0129] In the preferred embodiment, the touch screen GUI 1004 preferably enables the operator to touch a bar 1214 for a particular row to change the screen to the Level 3 Screen display for that selected row. All other buttons identified on FIG. 7 perform the same functions as described for FIG. 6 [0130] Placement Details Screen ( FIG. 8 ): FIG. 8 is an example of a preferred embodiment for displaying placement details in a bar graph format for all rows of a planter. In the example of FIG. 8 , a bar graph 1216 of the singulation details for a 32 row planter is shown. The number of rows displayed for the bar graph 1216 may be dynamic based on the number of rows entered during Setup. Alternatively, the number of rows may remain fixed on the screen with data only being displayed for the number of rows entered during Setup. [0131] The horizontal line 1220 on the bar graph 1216 corresponds to 100% good spacing (i.e., zero misplaced seeds) and the vertical scale of the bar graph 1216 preferably corresponds to a placement deviation limit (e.g., 10%) that may be specified during Setup. The numeric percent good spacing value 1144 for each row is graphically displayed as a data bar 1218 above a horizontal line 1220 . In the preferred embodiment, if a particular row approaches or exceeds the placement deviation limit, an alarm condition is triggered and the data bar 1218 for that row preferably includes a visual indication that it is in alarm condition. For example, in the preferred embodiment, the data bar 1218 for a row in an alarm condition is colored yellow (solid bars) whereas the data bars 1218 of the rows that are not in an alarm condition are green (clear bars). Alternatively, the data bars 1218 may flash under an alarm condition or change to a different color, such as red, under specific alarm conditions or depending on the severity of the yield robbing event. As with the Level 1 Screens, there are various ways to represent an alarm condition, by different colors, audible alarms, etc. Accordingly, any and all means of visually or audibly indicating an alarm condition should be considered within the scope of this invention. [0132] In the preferred embodiment, the touch screen GUI 1004 preferably enables the operator to touch a data bar 1218 for a particular row to change the screen to the Level 3 Screen display for that selected row. All other buttons identified on FIG. 8 perform the same functions as described for FIG. 6 . Level 3 Screens (FIGS. 9-12): [0133] Row Details ( FIG. 9 ): FIG. 9 is an example of a preferred embodiment for displaying Row Details. In the example of FIG. 9 , the row details for row “ 16 ” of the planter are illustrated. Preferably, the information displayed in this Level 3 Screen is similar to that displayed in the Level 1 Screen, except that in the Level 3 Screen, the information is row specific as opposed to averaged across all rows in the Level 1 Screens. Thus, the Level 3 Row Detail Screen preferably includes a Row Population window 1220 , a Row Singulation window 1222 , a Row Skips/Multiples window 1224 , a Row Down Force Window 1226 , a Row Vacuum Window 1228 (when applicable) and a Row Economic Loss window 1230 . The Level 3 Row Detail Screen also preferably includes a Row Good Spacing window 1232 and, preferably, a graphical Row Seed Placement window 1234 . The Home button 1209 , Row Details button 1032 , Up Arrow button 1206 , Down Arrow button 1208 , and Back button 1036 perform the same functions as described for FIG. 6 . [0134] Population window 1220 : The Population window 1220 preferably displays the row population value 1240 calculated as identified under the Level 1 Screen except that the row population value 1240 is specific to the selected row and is not averaged as in the Level 1 Screen. [0135] Singulation window 1302 : The Singulation window 1302 preferably displays the row percent singulation value 1242 calculated as identified under the Level 1 Screen except the row percent singulation value 1242 is specific to the selected row and is not averaged as in the Level 1 Screen. [0136] Row Skips/Multiples window 1224 : The Row Skips/Multiples window 1224 preferably displays the row % Skips value 1244 and the row % Mults value 1246 calculated as identified under the Level 1 Screen except these values are specific to the selected row and are not averaged as in the Level 1 Screen. [0137] Row Down Force window 1226 : The Row Downforce window 1226 is preferably only displayed on rows equipped with the load sensor 300 . When the row of interest is not equipped with a load sensor, the Row Downforce window is preferably blank. When the row of interest is equipped with a load sensor 300 , the Row Downforce window 1226 preferably cycles between the display of the downforce value 1248 (lbs), and/or the load margin, and/or the ground contact parameter 1250 . As disclosed in PCT/US08/50427 the downforce may be the load value (i.e., total load) detected during a predefined sampling period (e.g., 1 second time periods). The load margin is preferably the value calculated and/or derived as disclosed in PCT/US08/50427. Likewise, the ground contact parameter 1250 is preferably determined by the methods disclosed in PCT/US08/50427. [0138] Row Vacuum Window 1228 : The Row Vacuum Window 1228 is preferably only displayed on rows equipped with a vacuum sensor 700 . When the row of interest is not equipped with a vacuum sensor, the Row Vacuum window is preferably blank. When the row of interest is equipped with a vacuum sensor, the Row Vacuum window 1228 preferably displays the vacuum 1252 (in inches H 2 O) for that row. [0139] Row Economic Loss window 1230 : The Row Economic Loss window 1230 preferably displays the row economic loss value 1232 calculated as identified under the Level 1 Screen except the row percent singulation value 1254 is specific to the selected row and is not totaled across all rows as in the Level 1 Screen. [0140] Row Good Spacing window 1230 : The Row Good Spacing window 1230 preferably displays the row good spacing percentage value 1256 calculated as identified under the Level 1 Screen except the row good spacing percentage value 1256 is specific to the selected row and is not averaged as in the Level 1 Screen. [0141] Row Seed Placement window 1234 : The Row Seed Placement window 1234 preferably graphically displays a representation of each classified seed detected in that row (i.e., good, skip, multiple, misplaced2, misplaced4) over a distance behind the planter scrolling from the right hand side of the window to the left hand side of the window. In the preferred embodiment, good seeds are represented as green plants 1258 , skips are represented by a red circle-X 1260 , doubles and misplaced2 seeds are represented as red plants 1262 and misplaced4 seeds are represented as yellow plants 1264 . Of course, it should be appreciated that any other graphical representation of the seeds may be equally suitable and therefore any and all graphical representation of seed placement should be considered within the scope of the present invention. The Row Placement window 1234 preferably includes a distance scale 1266 representative of the distance behind the planter that the seeds/plants are displayed. Preferably the Row Placement window 1234 includes a “reverse” or rewind button 1268 , a “fast forward” button 1270 , and a play/pause button 1272 . The reverse button 1268 preferably causes the distance scale 1266 to incrementally increase in distance behind the planter (such as 25 feet) and scrolls the plants to the right (as opposed to the left) to permit the operator to review the seed placement further behind the planter. Alternatively, rather than scrolling the graphical representation of the seeds/plants, the reverse button may cause the scale to “zoom out,” for example the scale may increase at five foot increments to a scale of 0 to 25 feet instead of 0 to 10 feet. Similarly, the fast forward button 1270 permits the user to either scroll to the right up to zero feet behind the planter or to “zoom in” the distance scale. The play/pause button 1272 preferably permits the operator to pause or freeze the screen to stop the plants/seeds from scrolling and, upon pushing the button 1272 again, to resume the scrolling of the seeds. [0142] Row Selection ( FIG. 10 ): A preferred embodiment of the Row Selection Screen 1274 is illustrated in FIG. 10 in which a plurality of buttons 1276 are displayed corresponding to the row number of the planter. By touching a button 1276 corresponding to the row of interest, the preferred touch screen GUI 1004 displays the Level 3 Row Details Screen ( FIG. 9 ) for the selected planter row. The number of buttons 1276 displayed may vary depending on the size of the planter entered during Setup. Alternatively, the Row Selection Screen 1274 may have a fixed number of buttons 1276 corresponding to the largest planter available, but if the operator specifies a smaller number of rows during Setup, only the rows corresponding to the planter size entered would provide the foregoing functionality. All other buttons identified on FIG. 10 perform the same functions as described for FIG. 6 . The Row Details button 1032 is preferably not displayed in this screen. [0143] Setup Screen ( FIG. 1 1 : The preferred embodiment of a Setup Screen 1300 is illustrated in FIG. 11 . The Setup Screen 1300 preferably includes a plurality of predefined windows, each of which preferably displays relevant configuration information and opens a Level 4 Screen for entering that configuring information. The preferred windows include a Field window 1302 , a Crop window 1304 , a Population window 1306 , a Population Limits window 1308 , a Meter window 1310 , a Planter window 1312 , a Singulation Limits window 1314 , an Averaged Seeds window 1316 , an Ear Loss window 1318 and a File & Data Transfer window 1320 . The other buttons identified on FIG. 11 perform the same functions as described for FIG. 6 . The Row Details button 1032 is preferably not displayed in this screen. [0144] Field window 1302 : The Field window 1302 preferably opens a Level 4 Alpha-Numeric Keyboard Screen similar to the alpha-numeric keypad 1322 illustrated in FIG. 12 by which the operator can type alpha-numeric characters for entering a field identifier 1324 . Preferably, upon pressing the “Enter” button 1326 , the operator is returned to the Setup Screen 1300 and the field identifier 1324 is caused to be displayed in the Field window 1302 . [0145] Crop window 1304 : The Crop window 1304 preferably opens a Level 4 Crop Selection Screen 1328 , a preferred embodiment of which is illustrated in FIG. 12 . The Crop Selection Screen 1328 preferably includes a plurality of predefined crop-type buttons 1330 each having a crop type designator 1332 corresponding to the name of the most typical crops planted by row crop planters, namely, corn, beans, and cotton. Upon selecting one of these buttons, the operator is preferably returned to the Setup Screen 1300 and the corresponding crop-type designator 1332 is displayed in the Crop window 1304 . The Crop Selection Screen 1328 also preferably includes a button labeled “Other” 1334 , which upon selection, permits the operator to manually type in the name of the crop-type designator 1332 (e.g., sorghum or some other type of crop) into the window 1336 through the alpha-numeric keypad 1322 . Upon pressing the “Enter” button 1326 , the operator is returned to the Setup Screen 1300 and the crop designator 1322 manually typed in is displayed in the Crop window 1304 . The other buttons identified on FIG. 11 perform the same functions as described for FIG. 6 . [0146] Population window 1306 : The Population window 1306 preferably displays the target seed population 1338 . The target seed population 1338 may be a uniform target population, a variable population, or an exception population, and is preferably set through a Level 4 Population Settings Screen 1340 , a preferred embodiment of which is illustrated in FIG. 13 (discussed later). The Population Settings Screen 1340 preferably opens upon selection of the Population window 1306 through the preferred touch screen GUI 1004 . [0147] Population Limits window 1308 : The Population Limits window 1308 preferably opens the Level 4 Alpha-Numeric Keyboard Screen ( FIG. 12 ) as previously discussed by which the operator can type in the desired the population deviation limit 1342 if the operator does not wish to use the default limit of 1000 seeds. Preferably, upon pressing the “Enter” button 1326 , the operator is returned to the Setup Screen 1300 and the population deviation limit 1342 is caused to be displayed in the Population Limits window 1308 . The population deviation limit 1342 is the number of seeds by which the actual seed count may vary before setting off an alarm condition, and it is the value used in the scale of the bar graph 1200 in the Level 2 Population Details Screen of FIG. 6 . [0148] Meter window 1310 : The Meter window 1310 preferably opens a Level 4 Meter Selection Screen (not shown) through which the operator can select from among a plurality of predefined keys corresponding to the meter type 1344 of the metering device 30 used by the planter. The meter types preferably include finger meters and vacuum meters. Upon selection of the meter type 1344 , the operator is preferably returned to the Setup Screen 1300 and the meter type 1344 is preferably displayed in the Meter Window 1310 . [0149] Planter window 1312 : The Planter window 1312 preferably opens the Level 4 Alpha-Numeric Keyboard Screen ( FIG. 12 ) as previously discussed through which the operator can type in the number of rows 1346 on the planter and the row spacing 1348 of the planter. Preferably, upon pressing the “Enter” button 1326 , the operator is returned to the Setup Screen 1300 and the planter rows 1346 and row spacing 1348 are caused to be displayed in the Planter window 1312 . [0150] Singulation Limits window 1314 : The Singulation Limits window 1314 preferably opens the Level 4 Alpha-Numeric Keyboard Screen ( FIG. 12 ) as previously discussed through which the operator can type in the desired singulation deviation limit 1350 if the operator does not wish to use the default 1% singulation deviation limit. Preferably, upon pressing the “Enter” button 1326 , the operator is returned to the Setup Screen 1300 and the singulation deviation limits 1350 is caused to be displayed in the Singulation Limits window 1314 . The singulation deviation limit 1342 is the percentage by which the singulation may vary before setting off an alarm condition, and it is the percentage used in the scale of the bar graph 1210 in the Level 2 Singulation Details Screen of FIG. 7 . [0151] Averaged Seeds window 1316 : The Averaged Seeds window 1316 preferably opens the Level 4 Alpha-Numeric Keyboard Screen ( FIG. 12 ) as previously discussed through which the operator can type in the desired averaged seeds value 1352 if the operator does not wish to use the default averaged seeds value of 300. Preferably, upon pressing the “Enter” button 1326 , the operator is returned to the Setup Screen 1300 and the averaged seeds value 1352 is caused to be displayed in the Singulation Limits window 1314 . [0152] Ear Loss window 1318 : The Ear Loss window 1318 preferably opens the Level 4 Screen ( FIG. 12 ) as previously discussed through which the operator can type in the desired loss values 1354 if the operator does not wish to use the default values previously discussed. Preferably, upon pressing the “Enter” button 1326 , the operator is returned to the Setup Screen 1300 and the ear loss values 1354 entered by the operator are caused to be displayed in the Ear Loss window 1318 . As previously discussed, the ear loss values 1354 are used in calculating the row economic loss value 1254 displayed in the Row Economic Loss window 1230 ( FIG. 9 ) and the overall economic loss value 1176 displayed in the Economic Loss window 1028 ( FIG. 5 ). Level 4 Screen (FIG. 13): [0153] Population Settings Screen ( FIG. 13 ): The Population Settings Screen 1340 preferably includes a simple population window 1370 , preferably at least two variable population windows 1372 , 1374 and an Exception Population window 1376 . Each of the various population windows preferably includes a data window 1378 into which the population value 1338 may be entered for the particular population type selected. For example, if the operator intends to plant a field with a uniform population, the operator would select the simple population window 1370 and type in the desired population using the numeric keys in 1380 in the keypad window 1382 . Alternatively, if the operator wishes to vary the population over the field based on field mapping data, for example, the operator can select the first variable population window 1372 and enter the first variable population 1338 using the keys 1380 as before. The operator can then select the second variable population window 1374 and enter the second variable population value 1338 using the keys 1380 . If the operator wishes to plant different rows at different populations, for example when planting seed corn, the operator can select the exception population window 1376 and enter the seed population value 1338 for the exception rows using the keys 1380 . In the preferred embodiment, the operator can then preferably select the exception rows by touching the corresponding planter row indicator 1384 in the exception row window 1386 to which the exception population will apply. In the example of FIG. 13 , the operator has selected every fifth row of the planter to plant the exception population of 21000 seeds, whereas the non-highlighted rows will plant at the designated simple population of 31200 seeds. [0154] In the preferred embodiment, if the first variable population window 1372 is selected, the simple population window 1370 and the exception population window 1376 preferably change to variable population windows, thus allowing the operator to set four variable populations. [0155] The foregoing description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment of the apparatus, and the general principles and features of the system and methods described herein will be readily apparent to those of skill in the art. Thus, the present invention is not to be limited to the embodiments of the apparatus, system and methods described above and illustrated in the drawing figures, but is to be accorded the widest scope consistent with the spirit and scope of the appended claims.

A planter monitor system and method that provides an operator with near real-time data concerning yield robbing events and the economic cost associated with such yield robbing events so as to motivate the operator to take prompt corrective action.

BACKGROUND [0001] Drying clothes with a conventional clothes drying machine is well known. When utilizing a conventional dryer, clothes are typically spun, tossed and thrown around a drying bin at high temperatures. However, after a number of drying cycles clothes tend to shrink and become worn or discolored, among other things. Furthermore, certain articles of clothing, such as particularly delicate items, normally cannot be dried in this environment. These clothes must either be hung somewhere else, or taken to a costly dry cleaning shop where they are cleaned with harsh chemicals. [0002] Additionally, conventional clothes dryers consume a large amount of energy and have large operating costs. An average household dryer can consume upwards of 6000 watts per hour, and can cost somewhere between $1 and $2 per hour to operate depending on the time of day and the rate of electricity. Furthermore, throughout the life of the dryer, the energy consumed and the operating costs often increase. [0003] Moreover, conventional clothes dryers are large, heavy and generally immobile. Most clothes dryers take up a relatively large area in a home and are not easily moved within the home to create space. In addition, it is impractical to transport a conventional dryer for use in a location outside the home. SUMMARY [0004] One exemplary embodiment of the invention describes a clothes drying apparatus. The clothes drying apparatus can include a base portion with at least one blower. A drying chamber can be positioned above the base portion. A clothing frame can be housed within the drying chamber; the clothing frame having at least one vertical support member extending from the base portion, and at least one horizontal support frame member. A top portion can be removably coupled to the drying chamber. [0005] Another exemplary embodiment may include a method of drying clothes. The method includes steps for placing washed clothes into a drying chamber, sealing the drying chamber on all sides, and forcing air into the drying chamber from below utilizing at least one centrifugal blower. BRIEF DESCRIPTION OF THE FIGURES [0006] Advantages of embodiments of the present invention will be apparent from the following detailed description of the exemplary embodiments thereof, which description should be considered in conjunction with the accompanying drawings in which: [0007] FIG. 1 shows an exemplary embodiment of a clothes dryer. [0008] FIG. 2 shows an exemplary embodiment of a clothing frame for a clothes dryer. [0009] FIG. 3 shows another exemplary embodiment of a clothes dryer. DETAILED DESCRIPTION [0010] Aspects of the invention are disclosed in the following description and related drawings directed to specific embodiments of the invention. Alternate embodiments may be devised without departing from the spirit or the scope of the invention. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention. Further, to facilitate an understanding of the description discussion of several terms used herein follows. [0011] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Likewise, the term “embodiments of the invention” does not require that all embodiments of the invention include the discussed feature, advantage or mode of operation. [0012] FIG. 1 shows an exemplary embodiment of a clothes dryer 100 . Clothes dryer 100 may have a base portion 102 . Base portion 102 may be made of any suitable material, for example, molded plastic. Base portion 102 may be any suitable size, for example, a two foot by two foot square. Alternatively, base portion may be sized and shaped in any suitable manner known to a person of ordinary skill in the art. Base portion 102 may also have a liner, which may collect excess moisture. The liner may be formed of any material desired, for example, an absorbent fabric. [0013] At least one blower 104 may be disposed within base potion 102 . Alternatively base portion 102 may have a plurality of blowers 104 . Blowers 104 may be, for example, centrifugal blowers. The blowers 104 may be low volume, low speed blowers. For example, the blowers 104 may operate at about 100 to 200 cubic feet per minute (CFM) and may be powered by regular 120 volt household electricity. In other exemplary embodiments, blowers 104 may be powered in any manner, for example, by solar panels attached to the device. The blowers 104 may also be, for example, low discharge rate blowers. Blowers 104 may operate to force air from base portion 102 into drying chamber 106 . Heat may not need to be applied. However, in another exemplary embodiment, blowers 104 may blow heated air. Blowers 104 may operate utilizing ambient air including, for example, inside or outside ambient air. [0014] Clothes dryer 100 may have drying chamber 106 . Drying Chamber 106 may be removably coupled to base portion 102 . Alternatively drying chamber 106 and base portion 102 may be a single unit. Drying chamber 106 may be in fluid communication with base portion 102 . Drying chamber 106 may be above base portion 102 . Drying chamber 106 may be surrounded, wrapped or otherwise enclosed with a fire retardant material, for example a polyurethane or urethane coated nylon cloth, or any other decorative and/or functional material. [0015] Drying chamber 106 may contain clothing frame 108 . Clothing frame 108 may have at least one vertical support member 110 and least one horizontal support member 112 . Alternatively, clothing frame 108 may have a plurality of vertical support members 110 and horizontal support members 112 . Clothing frame 108 may also have at least one center bar disposed across horizontal support members 112 . Center bar may operate, for example, to allow clothes to be hanged in drying chamber 106 while clothes machine 100 is in operation. Vertical support member 110 may extend from base portion 102 . Horizontal support members 112 may be disposed at an angle to vertical support member 110 . Horizontal support members 112 may have a removable wire mesh layer. The removable wire mesh layer may operate, for example, to allow clothes to be laid within drying chamber 106 while clothes machine 100 is in operation. Clothing frame 108 may be made of any suitable material known to a person of ordinary skill in the art. For example, clothing frame 108 may be made of a galvanized coil spring. Clothing frame 108 may be made of a collapsible material, or alternatively, may be made of a rigid material, for example, a hard plastic, wood, or other suitable material. [0016] Clothes dryer 100 may have top portion 114 . Top portion 114 may operate to seal drying chamber 106 . Top portion 114 may be made of the same materials as drying chamber 106 . Top portion 114 may be removably coupled to drying chamber 106 by any means known to a person of ordinary skill in the art. For example, top portion 114 may be hinged, clasped, clamped or otherwise coupled to drying chamber 106 . [0017] Referring generally to clothes dryer 100 , clothes dryer 100 may be collapsible. For example clothes dryer 100 may be collapsed from a useable state into a smaller, portable state. Clothes dryer 100 may be collapsed in any manner, for example, using a lever, hinge or other means as desired. Alternatively, clothes dryer 100 may be rigid or may be stationary. Clothes dryer 100 may be customized to any suitable size known to a person of ordinary skill in the art. Clothes dryer 100 may be used inside or outside, and may further be transported to remote locations, for example, on a vacation. Clothes dryer 100 may further include a moisture sensor which may operate to shut clothes dryer 100 off once clothes in drying chamber 106 are dry. Clothes may be loaded into clothes dryer 100 via top portion 114 . Alternatively clothes may be loaded into clothes dryer 100 by other means, for example, via a side or front door. Clothes dryer 100 may also have, for example, an energy usage module, power monitor, and watt/hour monitor. [0018] Clothes dryer 100 may be an environmentally friendly apparatus that utilizes green technology. Clothes dryer 100 may utilize less energy than conventional clothes dryer, for example, the carbon footprint and green house emissions from clothes dryer 100 may be much smaller than conventional dryers as it may use significantly less power or energy than other known clothes dryers. Clothes dryer 100 may also operate at a much lower cost than traditional dryers. [0019] FIG. 2 shows an exemplary embodiment of clothing frame 108 . Clothing frame 108 may be within drying chamber 106 . Clothing frame 108 may have vertical support members 110 and horizontal support members 112 . Clothing frame 108 may have removable wire mesh 116 that may couple to horizontal support members 112 . Clothes may be placed across removable wire mesh 116 . Clothes dryer 100 may also have at least one center bar 118 . Alternatively, clothes dryer 100 may a have a plurality of center bars. Clothes may be hung from center bar 118 , for example, by a clothes hanger during operation of clothes dryer 100 . [0020] FIG. 3 shows another exemplary embodiment of clothes dryer 300 Clothes dryer 300 may have a base portion 302 . Base portion 302 may be made of any suitable material, for example, molded plastic. Base portion 302 may be any suitable size, for example, an about three foot by three foot square, and may have a height, for example, about eight inches. Alternatively base portion may be sized and shaped in any suitable manner known to a person of ordinary skill in the art. Control switch 316 may be disposed on base portion 302 . [0021] A plurality of centrifugal blowers 304 may be disposed within base potion 302 . The centrifugal blowers 304 may be low volume, low speed blowers. For example, the blowers 304 may operate at about 100 to 200 cubic feet per minute (CFM) and may be powered by regular 120 volt household electricity. In other exemplary embodiments, blowers 104 may be powered in any manner, for example, by solar panels or other green technology attached to the device. In some exemplary embodiments, solar panels may be coupled to any portion of clothes dryer 300 , for example exterior portions. The blowers 304 may also be, for example, low discharge rate blowers. Blowers 304 may operate to force air from base portion 302 into drying chamber 306 . Heat may not need to be applied. Blowers 304 may operate utilizing ambient air including, for example, inside or outside ambient air. [0022] Clothes dryer 300 may have drying chamber 306 . Drying Chamber 306 may be removably coupled to base portion 302 . Alternatively drying chamber 306 and base portion 302 may be a single unit. Drying chamber 306 may be in fluid communication with base portion 302 . Drying chamber 306 may be above base portion 302 . Drying chamber 306 may be surrounded, wrapped or otherwise enclosed with a fire retardant material, for example a polyurethane or urethane coated nylon cloth. Drying chamber 306 may be any suitable size. For example, drying chamber 306 may have a length of about three feet, a height of about three feet and a width of about three feet. [0023] Drying chamber 306 may contain clothing frame 308 . Clothing frame 308 may have vertical support member 310 and one or more horizontal support members 312 . Vertical support member 310 may extend from base portion 302 . Horizontal support members 312 may be disposed at an angle to vertical support member 310 . Horizontal support members 312 may have a removable wire mesh layer similar to that described earlier. The removable wire mesh layer may operate, for example, to allow clothes to be laid within drying chamber 306 while clothes machine 300 is in operation. Clothing frame 308 may be made of any suitable material known to a person of ordinary skill in the art. For example, clothing frame 308 may be made of a galvanized coil spring. Clothing frame 308 may be collapsible. When collapsed, the dimensions of clothes dryer 300 may be reduced. For example, clothes dryer may have a length of about two feet, a width of about two feet and a height of about fifteen inches when collapsed. Clothes dryer 300 may be stored, for example, in a carrying case. [0024] Clothes dryer 300 may have top portion 314 . Top portion 314 may operate to seal drying chamber 306 . Top portion 314 may be made of the same materials as drying chamber 306 . Top portion 314 may be removably coupled to drying chamber 306 by any means known to a person of ordinary skill in the art. For example, top portion 314 may be hinged, clasped, clamped or otherwise coupled to drying chamber 306 . [0025] The foregoing description and accompanying drawings illustrate the principles, preferred embodiments and modes of operation of the invention. However, the invention should not be construed as being limited to the particular embodiments discussed above. Additional variations of the embodiments discussed above will be appreciated by those skilled in the art. [0026] Therefore, the above-described embodiments should be regarded as illustrative rather than restrictive. Accordingly, it should be appreciated that variations to those embodiments can be made by those skilled in the art without departing from the scope of the invention as defined by the following claims.

Exemplary embodiments describe a clothes drying apparatus and a method for using a clothes drying apparatus. The clothes drying apparatus can include a base portion with at least one blower. A drying chamber can be positioned above the base portion. A clothing frame can be housed within the drying chamber; the clothing frame having at least one vertical support member extending from the base portion, and at least one horizontal support frame member. A top portion can be removably coupled to the drying chamber.

This is a continuation-in-part of application Ser. No. 08/584,528, filed Jan. 11, 1996, now abandoned. BACKGROUND 1. Field of Invention This invention relates to bicycle helmets, specifically to a transparent sun shield for a bicycle helmet. 2. Description of Prior Art Presently, bicycle helmets do not have sun shields. Currently, some bicycle helmets are made with visors. An example is the visored bicycle helmet in U.S. Pat. No. 5,333,328 to Roberts (1994). Visored bicycle helmets give a bicyclist eye protection against harmful ultraviolet rays. But, visors also block the upper peripheral view of the bicyclist, since visors are not transparent. OBJECTS AND ADVANTAGES The sun shield helmet assembly with eye shade portion made of material suitable to block out harmful ultraviolet radiation would protect the eyes from harmful exposure to the sun. In addition the interchangeable sun shields provide an added advantage, the wearer could change sun shields. If the bicyclist wanted to wear a blue sun shield on the helmet today and a green sun shield tomorrow, this could be accomplished with the interchangeable sun shields. Additionally, the interchangeable sun shields can be removed altogether, if the need for speed was a factor, like in professional racing. Since all of the eye shade portions of the sun shield helmet assembly are transparent they will not block the vision of the bicyclist. Further, the assembly can include a sticker or stickers attached to the eye shade portion, in an assortment of different colors, shapes and styles. More objects and advantages of my invention will become apparent from consideration of the drawings and ensuing description. DRAWING FIGURES In the drawings, identical figures have the same number. FIG. 1 is a perspective view of a bicycle helmet including an interchangeable sun shield. FIG. 2 is a perspective view similar to FIG. 1, but shows the component parts of the apparatus in a disassembled configuration. FIG. 3 is a top view of the assembly of FIG. 1, showing the sun shield secured to the helmet. FIG. 4 is a perspective view of a bicycle helmet including an interchangeable sun shield. FIG. 5 is a perspective view similar to FIG. 4, but shows the component parts of the apparatus in a disassembled configuration. FIG. 6 is an enlarged fragmentary view taken along lines 6--6 of FIG. 4. FIG. 7 is a perspective view of a bicycle helmet including an interchangeable sun shield. FIG. 8 is a perspective view similar to FIG. 7, but shows the component parts of the apparatus in a disassembled configuration. FIG. 9 is a top view of the assembly of FIG. 7, showing the sun shield secured to the helmet. FIG. 10 is a perspective view of a sun shield affixed to a bicycle helmet. FIG. 11 is a perspective view similar to FIG. 10, but shows the component parts of the apparatus in a disassembled configuration. FIG. 12 is a top view of the assembly of FIG. 10, showing the sun shield secured to the helmet. FIG. 13 is a perspective view of a sun shield affixed to a bicycle helmet. FIG. 14 is a perspective view similar to FIG. 13, but shows the component parts of the apparatus in a disassembled configuration. FIG. 15 is an enlarged fragmentary view taken along lines 15--15 of FIG. 13. FIG. 16 is a perspective view of a bicycle helmet with a built in sun shield. FIG. 17 is a perspective view similar to FIG. 16, but shows the component parts of the apparatus in a disassembled configuration. FIG. 18 is an enlarged fragmentary view taken along lines 18--18 of FIG. 16. FIG. 19 is a top view of one (1) component part of FIG. 17. REFERENCE NUMERALS IN DRAWINGS 20 helmet apparatus 22 shell 24 a front arcuate portion of shell 24a outside surface of 24 24b inside surface of 24 26 bottom shell rim 28 inner base 30 a front arch portion of inner base 30a outside surface of 30 30b inside surface of 30 32 bottom inner base rim 34 sun shield apparatus 36 a rear arcuate portion of sun shield 36a outside surface of 36 36b inside surface of 36 38 eye shade 40 rear sun shield edge 41 sticker 42 front sun shield edge 44 first engagement members strip (loop) 44a second engagement members strip (hook) 46L left fastening strap 46R right fastening strap 48 snap or pop type engagement member (male) 48a snap or pop type engagement member (female) 50 helmet apparatus 52 shell 54 a front arcuate portion of shell 54a outside surface of 54 54b inside surface of 54 56 bottom shell rim 58 inner base 60 bottom inner base rim 62 sun shield apparatus 64 a rear arcuate portion of sun shield 64a outside surface of 64 64b inside surface of 64 66 eye shade 68 rear sun shield edge 69 sticker 70 front sun shield edge 72L left fastening strap 72R right fastening strap 74 adhesive 76 helmet apparatus 78 sun shield shell 80 a circumferential portion of sun shield shell 80a outside surface of 80 80b inside surface of 80 81 eye shade edge 82 eye shade 83 sticker 84 adhesive 86 material 88L left vent hole 90 chin strap system 90a top front section 90b top rear section 91 strap end 92L left fastening strap 92R right fastening strap 93 strap adjuster 94 bifurcated male end 94a bifurcated female end 95 billet 96 inner protective base 98 a circumferential portion of base 98a outside surface of 98 98b inside surface of 98 100 apex 100a front portion 100b rear portion 102 base edge 104 material 106L left vent hole 106R right vent hole SUMMARY OF THE INVENTION An object of the invention is to provide protection for the eyes against harmful ultraviolet radiation, without blocking the vision. Another object is to provide a detachably interconnected, interchangeable transparent sun shield on a bicycle helmet, with an option to include sticker or stickers on the eye shade portion of the sun shield. Still another object is to provide an affixed transparent sun shield on a bicycle helmet with the same option to include sticker or stickers on the eye shade portion of the sun shield. Yet another object is to provide a new bicycle helmet with a built in sun shield. Also with the same option to include sticker or stickers on the eye shade portion of shell. DESCRIPTION OF THE INVENTION FIG. 1 (perspective view) a helmet apparatus 20 with a transparent sun shield apparatus 34 as they appear when interconnected. Shield 34 is detachably interconnected with helmet 20. Helmet 20 is commonly a bicyclist helmet and is accordingly configured. Helmet 20 insofar as the apparatus of the present invention is concerned, includes a protective shell 22 secured to a protective inner base 28. A left fastening strap 46L is secured and extends downwardly from a base rim 32. A right fastening strap 46R is secured and extends downwardly from rim 32. The apparatus of the present form of the invention may also include a sticker 41, which is affixed to the shield apparatus 34 in a manner presently to be described. In FIG. 2, shell 22 includes a generally arcuate front portion 24. Portion 24 has first and second, or outside and inside surfaces 24a and 24b. A first engagement members strip 44 of hook and loop material, which may be a multiplicity of a small loop shaped character to which the hook-like members of hook and loop material will releasably interlock. Strip 44 is fixedly attached to outside surface 24a, adjacent to a bottom shell rim 26. Sun shield 34 includes an eye shade portion 38 and a generally arcuate rear portion 36. Portion 36 has first and second, or outside and inside surfaces 36a and 36b. A second engagement members strip 44a, which may be a multiplicity of a small hook shaped character is fixedly connected to inside surface 36b, adjacent to a rear shield edge 40. In FIG. 3 outside surface 24a of shell 22 and inside surface 36b of shield 34 are provided with a multiplicity of small engagement members of hook and loop material 44 and 44a, which detachably interlock to hold surfaces 24a and 36b in position, causing shield 34 to be maintained securely in place on shell 22. Shield 34 is basically convexed in shape along a front edge 42 and basically concaved in shape along rear edge 40, to conform to the shape of virtually any bicyclist helmet. In the preferred form of the invention transparent shield 34 is of 100% shatterproof, non toxic material suitable for blocking ultraviolet radiation. Shield 34 may be attached to or removed from helmet 20. Additionally shield 34 is interchangeable. A variety of sun shields can be worn on just one helmet. Shield 34 may be replaced by another shield 34 of a different color and/or design. In addition shield 34 may be multicolored. Also in FIG. 3 the previously identified sticker 41 is fixedly attached to eye shade portion 38. Sticker 41, which is preferably backed with an adhesive material, may be of a variety of materials, shapes, colors and sizes. A plurality of sticker 41 may be used, which is not shown. Sticker 41 is an optional feature on eye shade portion 38 of shield 34. Turning now to FIG. 4, the helmet apparatus 20 with transparent shield apparatus 34. This second form of the invention is identical to the first embodiment shown in FIGS. 1 through 3, except for the detachable interlocking position of shield 34 and helmet 20. This second embodiment has the same numbers as the first embodiment to identify the same elements. Shield 34 in now shown interconnected in an inverse position from FIGS. 1, 2, and 3. As with the earlier described embodiment, this form can also include sticker 41, which is affixed to eye shade portion 38 of shield 34. This second form includes sticker 41 in the exact same manner as the first embodiment previously described in FIGS. 1 through 3. Referring to FIG. 5, the inner base 28 includes a generally arched front portion 30. Portion 30 has first and second, or outside and inside surfaces 30a and 30b. Previously mentioned first engagement member strip 44 is fixedly connected to inside surface 30b, slightly adjacent to inner base rim 32. First strip 44 preferably has loop members, of hook and loop material. On sun shield 34, second engagement members strip 44a is fixedly connected to outside surface 36a, adjacent to rear shield edge 40. Second strip 44a preferably has hook members, of hook and loop material. In FIG. 6 inside surface 30b of inner base 28 and outside surface 36a of shield 34 are provided with a multiplicity of small engagement members of hook and loop material 44 and 44a, which detachably interlock to hold surfaces 30b and 36a in position, causing shield 34 to be maintained securely in place on helmet 20. Shield 34 may be removed from or attached to helmet 20, making this alternate form also interchangeable. Shifting to FIG. 7 (perspective view), helmet apparatus 20 with transparent shield 34 of yet another form of the invention is thereshown. This third form is identical to the first embodiment shown in FIGS. 1 through 3, except for a different means for removably interconnecting the shield 34 to the helmet 20. This third embodiment has the same numbers as the first embodiment to identify the same elements. As with the first described embodiment, this form can also include sticker 41, which is affixed to eye shade portion 38 of shield 34. This third form includes sticker 41 in the exact same manner as the first embodiment previously described in FIGS. 1 through 3. In FIG. 8, Previously mentioned shell 22 having outside surface 24a of which is provided with a plurality of snap or pop type engagement member 48 to which a plurality of cooperating snap or pop type engagement member 48a can be releasably interconnected. Surface 24a preferably provided with the male segments of snap or pop type engagement members, adjacent to bottom rim 26. As previously described, shield 34 includes an arcuate rear portion 36 with an inside surface 36b of which is provided with a plurality of snap or pop type engagement member 48a, adjacent to rear edge 40. Surface 36b preferably provided with the female segments of snap or pop type engagement members. In FIG. 9 outside surface 24a of shell 22 and inside surface 36b of shield 34 are provided with a multiplicity of cooperating snap or pop type engagement members 48 and 48a, which detachably interlock to hold surfaces 24a and 36b in position, causing shield 34 to be maintained securely in place on helmet 20. Shield 34 may be removed from or attached to helmet 20, making this third alternate form also interchangeable. All of the previously mentioned forms of the present invention are interchangeable sun shields. In using the earlier described forms the wearer can change the look of the helmet by removing the sun shield and replacing it with another sun shield. Unlike the previously mentioned forms, this fourth form is not an interchangeable sun shield; but the sun shield is affixed to the helmet apparatus, in a non-rotatable manner. In FIG. 10, the fourth form of the sun shield apparatus of the present invention and the helmet are thereshown. A helmet apparatus 50 with a transparent sun shield apparatus 62 as they appear when connected. Helmet 50 is commonly a bicyclist helmet and is accordingly configured. Helmet 50 insofar as the apparatus of the present invention is concerned, includes a protective shell 52 secured to a protective inner base 58. A left fastening strap 72L is secured and extends downwardly from a base rim 60. A right fastening strap 72R is secured and extends downwardly from rim 60. Like the previous forms of the invention, this fourth form may also include a sticker 69, which is affixed to the shield apparatus 62 in a way presently to be described. Referring to FIG. 11, shell 52 includes a generally arcuate front portion 54. Portion 54 has first and second, or outside and inside surfaces 54a and 54b. An adhesive 74 is placed along outside surface 54a, alongside a bottom shell rim 56. Sun shield 62 includes an eye shade portion 66 and a rear generally arcuate portion 64. Portion 64 has first and second or outside and inside surfaces 64a and 64b. Previously mentioned adhesive 74 is also placed along inside surface 64b, alongside a rear shield edge 68. In FIG. 12 outside surface 54a of shell 52 and inside surface 64b of shield 62 are placed together at adhesive locations to unite. As with the previous forms of the present invention, shield 62 is generally convexed in shape along a front sun shield edge 70 and generally concaved in shape along rear edge 68, to conform to the shape of virtually any bicyclist helmet. In the preferred form of the invention, transparent shield 62 is of 100% shatterproof, non toxic material suitable for blocking ultraviolet radiation. Also in FIG. 12 the previously identified sticker 69 may be fixedly attached to eye shade portion 66. Sticker 69, which is preferably backed with an adhesive material, may be of a variety of materials, shapes, colors and sizes. A plurality of sticker 69 may be used, which is not shown. Sticker 69 is an optional feature on eye shade portion 66 of shield 62. Shifting now to FIG. 13, helmet apparatus 50 with transparent shield apparatus 62. This fifth form of the invention is identical to the fourth embodiment shown in FIGS. 10 through 12, except for the connecting position of shield 62 and helmet 50. This fifth embodiment has the same numbers as the fourth embodiment to identify the same elements. Shield 62 is now in an inverse position from the fourth form in FIGS. 10, 11 and 12. As with the fourth described embodiment, this form can also include sticker 69, which is affixed to eye shade portion 66 of shield 62. This fifth form includes sticker 69 in the exact same manner as the fourth embodiment previously described in FIGS. 10 through 12. In FIG. 14, the previously mentioned shell 52 having inside surface 54b. Adhesive 74 is placed along inside surface 54b, adjacent to bottom shell rim 56. On sun shield 62 adhesive 74 is placed along outside surface 64a, adjacent to rear sun shield edge 68. In FIG. 15 inside surface 54b of shell 52 and outside surface 64a of shield 62 are placed together at adhesive locations to unite. Changing now to FIG. 16 (perspective view), this form is substantially different from the forms previously described. The prior art of the helmet apparatus is not used. A helmet apparatus 76 of the present invention, encompasses a transparent sun shield shell 78 and an integral inner protective base 96. Shell 78 and base 96 are shown as they appear when connected, in a non-rotatable manner. The apparatus of the present invention also includes a chin strap 90, which is affixed to base 96. Resembling the previous forms of the invention, this form may also include a sticker 83, which is affixed to shell 78 in a manner presently to be described. In FIG. 17, Shield shell 78 includes a left vent hole 88L and a right vent hole, which is not shown. Shell 78 also includes a generally circumferential portion 80, which extends around shell 78. Portion 80 has first and second, or outside and inside surfaces 80a and 80b. An adhesive 84 is placed along inside surface 80b. Shell 78 is largely dome like in shape, except for shade portion 82, which is convex shaped, along an eye shade edge 81 and extends outwardly and downwardly. Shell 78 is preferably made of a transparent plastic material 86 or the like. base 96 includes a circumferential portion 98, which extends around base 96. Portion 98 has first and second or outside and inside surfaces 98a and 98b. Previously mentioned adhesive 84 is also placed along outside surface 98a, slightly adjacent to a base edge 102. Base 96 is generally dome shaped, having an apex 100, at the top. Base 96 preferably is made of a styrofoam material 104 or the like. In FIG. 18 inside surface 80b of shell 78 and outside surface 98a of base 96 are placed together at adhesive locations to connect. Adhesive 84 should be made of substance suitable for a connection, preferably a pellucid adhesive. In FIG. 19, base 96 includes apex 100, which incorporates a front portion 100a and a rear portion 100b. In addition base 96 includes a left vent hole 106L and a right vent hole 106R. Chin strap system 90 includes a top front section 90a and a top rear section 90b. front section 90a is superimposed on front portion 100a and is placed through left vent hole 106L and right vent hole 106R. Rear section 90b is superimposed on rear portion 100b and is also placed through left vent hole 106L and right vent hole 106R. In FIG. 17, on base 96, chin strap system 90 also includes a right fastening strap 92R and a left fastening strap 92L. Right fastening strap 92R preferably having a bifurcated male end 94 extends downwardly from base edge 102. Right fastening strap 92R also includes a strap adjuster 93 and a billet 95. Strap adjuster 93, regulates the length of right strap 92R, permitting the right strap 92R to be shortened or loosened as desired. Billet 95 holds a strap end 91 in position, keeping end 91 from dangling. Left fastening strap 92L preferably having a bifurcated female end 94a extends downwardly from base edge 102. Left fastening strap 92L, also includes strap adjuster 93, which regulates the length of the left strap 92L, permitting the left strap 92L to be shortened or loosened as desired. End 94 and end 94a, of chin strap system 90, are coupled together by means of conventional male and female interconnecting clip or clasp members. In FIG. 16, the previously identified sticker 83 may be fixedly attached to eye shade portion 82. Sticker 83, which is preferably backed with an adhesive material, may be of a variety of materials, shapes, colors and sizes. A plurality of sticker 83 may be used, which is not shown. Sticker 83 is an optional feature on eye shade portion 82 of shell 78. Having now described the invention in detail in accordance with the requirements of the patent statues, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet the specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention. An example of a change is with the interchangeable sun shields. The sun shields can have a fabric trimming around the edges. Accordingly, the scope of the invention should be determined not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents.

A bicycle helmet having a transparent eye shade and various interchangeable sun shield portions, along with affixed sun shield portions, also including a helmet with a built in sun shield. Sticker or stickers of various styles can be connected to all eye shade portions of the assemblage.

BACKGROUND [0001] To meet the demand for natural resources, companies invest significant amounts of time and money in searching for and extracting oil, natural gas, and other subterranean resources from the earth. Systems are often employed to access and extract the desired resource. These systems may be located onshore or offshore, depending on the location of the resource, and generally include a wellhead assembly through which the resource is extracted. These wellhead assemblies may include a wide variety of components, such as various casings, hangers, valves, fluid conduits, and the like, that control system operations. Sometimes it is difficult, as well as expensive, to get direct access to a well through the wellhead assembly while maintaining pressure-containing barriers to protect against release to the surrounding environment. [0002] Wellhead assemblies may include a tree, i.e., an assembly of pipes, valves and fittings coupled to a wellhead housing or hub to control the flow of oil and gas produced from the well and/or to control the flow of fluids injected into the well, a spool, or other completion member. Completion members are manufactured for surface or subsea applications, and can be vertical, horizontal, or a variation or hybrid thereof in configuration. [0003] Vertical completion members generally include one or more production passages containing valves, where each production passage is in-line with the production tubing. Vertical completion members generally may be removed while leaving the completion (e.g., the production tubing hanger and production tubing) in place; however, if it is necessary to pull the completion, a vertical completion member may be removed and replaced with a blowout preventer (BOP), a lengthy operation that may leave the well in a vulnerable condition during plugging and/or killing operations and/or exchange of the completion member and BOP pressure-control devices. [0004] Horizontal completion members may be arranged with production control valves offset from the production tubing and with the tubing hanger locked and sealed in the member passage (instead of the wellhead) after the completion member is installed. With a horizontal configuration, the completion (e.g., the production tubing hanger and production tubing) may be removed without having to remove the completion member from the wellhead housing. However, if the member needs to be removed, the entire completion typically also is removed. [0005] To manage expected maintenance costs, which are especially high for an offshore well, the well operator may select equipment best suited for the expected type of maintenance predicted to be required over the life of the well. For example, a well operator may predict whether there will be a greater need in the future to pull the completion member from the well for repair, or pull the completion, either for repair or for additional work in the well. Depending on the predicted maintenance events, an operator will decide whether the horizontal or vertical configuration, or a variation or hybrid thereof, each with its own advantages and disadvantages, is best suited for the expected conditions. For instance, with a vertical configuration, it is more efficient to pull the completion member and leave the completion in place. However, if the completion is pulled, the completion member is pulled as well, increasing the time and expense of pulling the completion. Conversely, with a horizontal configuration, it is more efficient to pull the completion, leaving the completion member in place. However, if the completion member is pulled, the completion is pulled as well, increasing the time and expense of pulling the member. [0006] Another factor an operator may weigh in completion member selection is the relative bore size available for access. With the production valves offset from the production tubing, a horizontal configuration generally has a relatively larger bore. This allows the tubing and tubing hanger to be removed, for instance, or other downhole operations to be performed, without having to remove the completion member from the wellhead or disturb any external connectors to flowlines, service lines, or the like—thereby saving risk, time, and cost. Moreover, due to its large bore configuration, the horizontal configuration can accommodate larger equipment such as electrical submersible pump (ESP) completions. [0007] An additional factor an operator may weigh in completion member selection relates to the operational impact of the so-called dual barrier requirement. Regulations in certain jurisdictions and other industry practices require a subsea well access system to provide at least two full-bore pressure-containing safety barriers between the well and open water environment at all times. For a vertical configuration, these barriers may be provided by valves such as master valves and swab valves, for example, which may be actuated to open at any time while a safety package is in place. [0008] For a horizontal configuration, pressure-containing barriers may be provided by crown plugs sealed in the vertical passage of the tubing hanger above the production outlet and in the vertical passage of an internal tree cap landed in the completion member above the tubing hanger, where a so-called tree cap may be used with a tree, spool, or any other completion member. However, the well can be accessed only after the crown plugs have been physically removed. Removal and installation of crown plugs in a horizontal configuration each require a separate trip by wireline, slickline, braided line, or coiled tubing, and such subsea well intervention operations are generally very expensive, often based on hourly or daily rig charges. Moreover, in some cases the plug removal can be made more difficult due to the presence of corrosion, encrustation, debris, differential pressure across the plug, etc., thereby further adding to the cost of intervention. [0009] An actuatable valve also may provide a pressure-containing barrier in one or more location. However, regardless of whether a crown plug or an actuatable valve is provided as a pressure-containing barrier in the tubing hanger bore, the location is problematic as tubing hangers may already have complex elements such as contingency plug profiles, for example. Moreover, providing a valve such as a gate valve in an internal tree cap as a final pressure-containing barrier may not provide complete control against leakage to the environment. DRAWINGS [0010] Embodiments of a well access system are described with reference to the following figures. The same numbers are used throughout the figures to reference like features and components. The features depicted in the figures are not necessarily shown to scale. Certain features of the embodiments may be shown exaggerated in scale or in somewhat schematic form, and some details of elements may not be shown in the interest of clarity and conciseness. [0011] FIG. 1 shows a cross-sectional view of a well access system in accordance with one or more aspects of the present disclosure; [0012] FIG. 2 shows a cross-sectional view of a well access system in accordance with one or more aspects of additional embodiments of the present disclosure; [0013] FIG. 3 shows a cross-sectional view of a well access system in accordance with one or more aspects of additional embodiments of the present disclosure; [0014] FIG. 4 shows a cross-sectional view of a well access system in accordance with one or more aspects of additional embodiments of the present disclosure; and [0015] FIG. 5 shows a cross-sectional view of a well access system in accordance with one or more aspects of additional embodiments of the present disclosure. [0016] FIG. 6 shows a cross-sectional view of an upper portion of the well access system in accordance with one or more aspects of additional embodiments of the present disclosure. DETAILED DESCRIPTION [0017] The present disclosure relates generally to systems and methods for providing access to a well without the operational need to replace pressure-containing barriers between the well and the environment. [0018] One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. [0019] When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, any use of any form of the terms “connect,” “engage,” “couple,” “attach,” or any other term describing an interaction between elements is intended to mean either an indirect or a direct interaction between the elements described. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis. The use of “top,” “bottom,” “above,” “below,” and variations of these terms is made for convenience, but does not require any particular orientation of the components. [0020] Certain terms are used throughout the description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. [0021] Accordingly, disclosed herein is a system and method for well access that may include and/or be used with a tree, spool, or other completion member. The tree may be a subsea tree or a surface tree, a vertical tree or a horizontal tree, a mono bore or a multi bore tree, a production tree or an injection tree, or any combination or further variation. The spool may be an adapter spool, a tubing spool, a flow spool, or any completion spool member. Completion members may be used in combination; for example, a tree may be installable on other components of the well access system, such as installable on or within a wellhead and/or a tubing spool, for instance. [0022] FIG. 1 is a schematic diagram that illustrates a well access system 10 . The illustrated well access system 10 can be configured to extract various minerals and natural resources, including hydrocarbons (e.g., oil and/or natural gas), or configured to inject substances into the earth. In some embodiments, the well access system 10 is land-based (e.g., a surface system), and in other embodiments, the well access system 10 is subsea (e.g., a subsea system). As illustrated in FIG. 1 in accordance with one or more embodiments of the present disclosure, well access system 10 is a subsea system that includes a horizontal tree 12 directly or indirectly connected to wellhead hub 18 , which can be a high pressure wellhead housing or tubing spool or another wellhead member or tree member. The wellhead hub 18 generally is disposed at the upper termination of a well bore and provides for the connection to the well. [0023] In FIG. 1 , tree 12 having a bore 13 is shown as mounted on tree connector 16 . Subsea trees generally have at least two bores, one of which communicates with the production tubing (the production bore) 20 via production line 22 , and the other of which communicates with the production tubing annulus (the annulus bore) 24 via annulus flow line 26 . A tubing hanger 44 with a production bore is landed in the tree 12 and supports the production tubing 20 extending into the well. [0024] Typical designs of horizontal tree 12 have a fixed lateral connection or side outlet 14 (a production wing branch) to the production bore 20 closed by at least one production valve 30 for removal of production fluids from the production bore 20 . The annulus bore 24 also may have an annulus wing branch 15 with one or more respective annulus valve(s) 32 , 34 . [0025] In FIG. 1 , the top of the production bore and the top of the annulus bore are capped by an internal tree cap 40 , which seals off the various bores in the tree 12 and provides channels for operation of the various valves in the tree 12 by means of intervention equipment or remotely from an offshore installation. Internal tree cap 40 may be installed by equipment run through a riser connected to vessel, platform, or other pipe location on or closer to the sea surface, for example, or may be installed in open water by remotely operated vehicle (ROV) assistance. [0026] The internal tree cap 40 is sealed to the tubing hanger body 44 with one or more seal(s) 45 . The internal tree cap 40 is also sealed to the tree bore with one or more seal(s) 48 . The internal tree cap 40 includes a central production bore capable of fluid communication with production flow line 22 and/or production bore 20 and an annulus bore 28 capable of fluid communication with annulus flow line 26 and/or annulus bore 24 . [0027] In the embodiment of FIG. 1 , a valve 60 is built into the internal tree cap 40 , which has relatively more volume for such valve than tubing hanger 44 . As shown in FIG. 1 , valve 60 is a spherical gate valve; however, valve 60 built into internal tree cap 40 also may be a ball valve or any other type of valve for sealing a flow passageway in the desired environment. Valve 60 is hydraulically, mechanically, and/or electrically actuatable between an open position and a closed position using one or more of control lines 66 , 68 . Control lines 66 , 68 used to open and close valve 60 may be ported to a surface or subsurface control system or to ROV hot stabs, for example. When in the closed position, valve 60 may provide a production and/or annulus pressure-containing barrier to the environment. [0028] An open water tree cap 80 is shown installed within the bore, i.e. inside an internal profile, of internal tree cap 40 . Open water tree cap 80 may be installed in the inner bore of internal tree cap 40 . Open water tree cap 80 may be installed by equipment run through a riser connected to vessel, platform, or other pipe location on or closer to the sea surface, for example, or may be installed in open water by ROV. The open water tree cap 80 is sealed to the internal tree cap 40 with one or more seal(s) 85 . Open water tree cap 80 , when installed inside internal tree cap 40 and when valve 60 is in the closed position, may provide a production and/or annulus pressure-containing barrier to the environment. [0029] Referring to FIG. 2 , another embodiment of the present disclosure, a plug 260 installed in the bore of the tubing hanger 44 or a plug (not shown) installed at location 280 in the bore of the internal tree cap 40 may provide a production and/or annulus pressure-containing barrier to the environment, where the open water tree cap 80 disclosed above may provide a production and/or annulus pressure-containing barrier to the environment. [0030] Referring to FIG. 3 , another embodiment of the present disclosure, in addition to actuatable valve 60 installed in the bore of the internal tree cap 40 , an additional actuatable valve 300 is installed in the production bore 20 below the tubing hanger 44 . As shown in FIG. 3 , valve 300 is a spherical gate valve; however, valve 300 installed below the tubing hanger also may be a ball valve or any other type of valve for sealing a flow passageway in the desired environment. Valve 300 is hydraulically, mechanically, and/or electrically actuatable between an open position and a closed position using one or more of control lines 301 , 302 . Control lines 301 , 302 used to open and close valve 300 may be ported to a surface or subsurface control system or to ROV hot stabs, for example. When in the closed position, valve 300 may provide a production and/or annulus pressure-containing barrier to the environment, with or without valve 60 also being in a closed position. The open water tree cap 80 disclosed above may provide a production and/or annulus pressure-containing barrier to the environment. [0031] Referring to FIG. 4 , when the open water tree cap 80 of this disclosure is removed, the configuration of this disclosure allows a riser 430 to be installed, through insertion of stab 410 into the bore of the internal tree cap 40 and use of riser connector 460 , to facilitate a full production bore well kill. The stab 410 is sealed to the internal tree cap body 40 with one or more seal(s) 420 configured around the outer surface of the stab 410 . Riser 430 includes at least one production bore 440 and annulus bore 450 and can be a light weight intervention (LWI) riser, lower marine riser package (LMRP), lower riser package/emergency disconnect package (LRP/EDP), high pressure riser system, intervention riser, workover riser, or any other type of riser or equipment used for fluid communication between the well access system 10 and a vessel, platform, or other pipe location on or closer to the sea surface. In operation, when the open water tree cap 80 is removed to install the riser 430 , the valve 60 in internal tree cap 40 will be tested and closed. In addition, the surface controlled subsurface safety valves (SCSSV) downhole will be closed, allowing two barriers for the short period before the riser connection 460 is established on the well access system 10 . [0032] FIG. 5 illustrates one or more embodiments of the present disclosure in which well access system 110 includes a vertical tree or an adapter spool 112 directly or indirectly connected to wellhead hub 158 , which can be a high pressure wellhead housing or tubing spool or another wellhead member or tree member. [0033] In FIG. 5 , tree or adapter spool 112 is shown as mounted on tree connector 116 and as having at least one production bore 120 , with one or more production valves 170 , 172 therein, and at least one annulus bore extending from the production tubing/casing annulus in the well (not shown) through annulus bore 124 in tubing hanger 155 and through annulus bore 126 with one or more annulus valves 132 , 134 in the annulus wing branch 115 of tree or adapter spool 112 . A tubing hanger 155 with a production bore is landed in the tree or adapter spool 112 and supports the production tubing 120 extending into the well. A side outlet 174 is equipped with a valve 176 . [0034] In FIG. 5 , the top of the production bore and the top of the annulus bore are capped by an internal tree cap 140 , which seals off the various bores in the tree or adapter spool 112 and provides channels for operation of the various valves in the tree or adapter spool 112 by means of intervention equipment or remotely from an offshore installation. Internal tree cap 140 may be installed by equipment run through a riser connected to vessel, platform, or other pipe location on or closer to the sea surface, for example, or may be installed in open water by ROV. The internal tree cap 140 is sealed to the tree or adapter spool body 112 with one or more seal(s) 145 , 146 . The internal tree cap 140 includes a central production bore capable of fluid communication with production bore 120 and an annulus bore 128 capable of fluid communication with annulus flow line 126 . [0035] In FIG. 5 , an open water tree cap 180 is installed inside internal tree cap 140 . Open water tree cap 180 may be installed by equipment run through a riser connected to vessel, platform, or other pipe location on or closer to the sea surface, for example, or may be installed in open water by ROV. The open water tree cap 180 is sealed to the internal tree cap 140 with one or more seal(s) 185 . Open water tree cap 180 , when installed inside internal tree cap 140 and when one or more of valves 170 and 172 are in the closed position, may provide a production and/or annulus pressure-containing barrier to the environment. [0036] FIG. 6 shows an open water tree cap 680 installed around an internal tree cap 40 and sealed to an external profile of internal tree cap 40 with one or more seal(s) 685 . Although FIG. 6 shows the configuration including a valve in the internal tree cap of FIGS. 1 and 3 , any open water tree cap of the present disclosure may be installed inside an internal profile, or above and/or around an external profile, of an internal tree cap. [0037] The seals shown in FIGS. 1-6 may be made of metal, elastomer, thermal plastic compounds, other sealing material, or a variation or combination thereof. [0038] The present invention can be applied with different surface intervention systems as well as subsea intervention systems including but not limited to a tensioned riser system, a compliant riser system, a spoolable compliant guide system, a subsea lubricator system, a light weight intervention system, and any other intervention system which includes a subsea intervention package connected above the subsea tree or adapter spool. [0039] Although the preceding description has been described herein with reference to particular means, materials and embodiments, it is not intended to be limited to the particulars disclosed herein; rather, it extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.

A system and method for accessing a well is disclosed. The system includes a first cap positionable within a bore of a completion member such as a tree or a spool. The first cap has a sealable interface to accept a second cap, and the second cap when sealed to the first cap is capable of providing a barrier against a release of well fluid external to the well.

TECHNICAL FIELD This invention is related to well swab cup internal constructions. More specifically, the invention is related to swab cup internal constructions which are adapted to position and support the swab cup reinforcing members or wires within the elastomeric cup like body. BACKGROUND OF THE INVENTION In the manufacture of well swab cups, the cage consisting of the bushing and the wires or support members is formed of separate parts then assembled into a skeletal like configuration. Once this is done, the cage is placed in a mold cavity and the mold cavity is filled with an elastomeric compound to complete the molding process. Because of the relatively large quantity of swab cups that are manufactured, the bushing is constructed so the wires can be easily slipped into place in the mounting portion of the bushing. In order to assure ease in assembly, apertures through the bushing which support the wires are substantially larger than the normal or typical wires to allow for rapid assembly. Because of this loose fit, wires which are only supported by a single mount or contact with the bushing tend to become displaced during the molding process from a regularly spaced arrangement around the bushing to an irregular arrangement that may have a substantial gap between certain of the wires while others are substantially closer together than may be desirable. When a swab cup is made with an excessively large gap between some of the wires while the others are abnormally close together, this will create a weakened sidewall of the cup body. This weakened wall portion will cause the cup to blowout or become peforated through a portion of the cup sidewall at the large gap thus destroying the swab cup. Prior art swab cup constructions have overcome this problem of maintaining this spaced relation of the wires during molding by rigidly clamping the lower ends of the wires. This solution will overcome the problem of positioning the wires, however, it makes the lower portion of the swab cup extremely rigid; therefore, it is not a feasible solution for swab cups which must flex radially a significant amount in their lower as well as in their upper portions. SUMMARY OF THE INVENTION In an embodiment, a swab cup structure includes an elastomeric cup like body containing a bushing in its lower end portion with a plurality of wires or reinforcing members mounted around the bushing, and a support member or guide above the bushing to position the wires in a uniformed spaced relation around the periphery of the swab cup. The bushing is provided with a plurality of apertures around the outer periphery of its lower portion in which are mounted the lower ends of the U-shaped wires. These wires are located in a uniformly spaced relation around the periphery of the bushing and extend upward to a longitudinal mid-portion of the swab cup. The support member or wire guide is positioned above the bushing and has a plurality of spaced recesses to engage and support the mid-portion of the wires in order to prevent the wires from tipping or being longitudinally angularly displaced around the swab cup periphery from their uniformly oriented location around the bushing. One object of this invention is to provide a swab cup structure overcoming the aforementioned disadvantages of the prior art devices in alignment and permanent positioning of the support members or wires. Still, another object of this invention is to provide a swab cup structure which has a bushing to mount the reinforcing members or wires and an additional member to position the wires in a spaced relation around the circumference of the swab cup for maintaining the wires in this location during molding of the swab cup body. Various other objects, advantages and features of this invention will become apparent to those skilled in the art from the following discussion, taken in conjunction with the accompanying drawing, in which: DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation view of a swab cup constructed in accordance with this invention and having a quarter section thereof cutaway for clarity and with some wires thereof shown in phantom lines; FIG. 2 is a plan view of the annular support member or wire guide alone; and FIG. 3 is a transverse sectional view of the swab cup taken at the location of line 3--3 in FIG. 1. The following is a discussion and description of preferred specific embodiments of the swab cup structure of this invention. Such being made with reference to the drawing, whereupon the same reference numerals are used to indicate the same or similar parts and/or structure. It is to be understood that such discussion and description is not to unduly limit the scope of the invention. DETAILED DESCRIPTION Referring to the drawings in detail and in particular to FIG. 1, a well swab cup 10 is shown with a section thereof cutaway exposing the bushing 12, the reinforcing members or wires 14 and the annular support or wire guide, indicated generally at 16. Swab cup 10 is a flexible cup shaped member with an opening through the bottom thereof to permit mounting on a mandrel with the flexible upper portion of the cup being upwardly directed. Bushing 12 is an elevated hollow member which makes the lower portion of the swab cup relatively rigid and mounts the lower end portions of the reinforcing members or wires. Bushing 12 has a lower lip 18 around the outer periphery of the lower portion thereof. Lower lip 18 is provided with a plurality of spaced apertures therethrough for receiving the lower end portions of wires 14 and interlocking or interfitting with them. The upper portion of bushing 12 has an upwardly and radially outwardly disposed upper lip 20 which is located radially inward of wires 14 relative to the longitudinal axis of swab cup 10. The top of bushing 12 is an annular upwardly facing surface 22. Bushing 12 has an internal bore 23 defining its interior. Wires 14 are reinforcing members for the flexible swab cup body 24 and they are connected to bushing 12 for support at their lower end. Specifically, wires 14 of this swab cup are generally U-shaped members with the closed end portion of the U indicated at 26 and being on the upper end thereof. Wires 14 have their lower end portions 28 bent in curved fashion about an imaginary radius pivot point external to the swab cup so they will interlock with the apertures in bushing lower lip 18. Wires 14 each have their mid-portion 30 curved oppositely to their lower portion 28 and positioned well within the mid-portion of swab cup body 24. As can be seen in FIG. 3, the wires are positioned in a spaced relation around the periphery of bushing 12 in order to provide a uniformed support of resilient swab cup body 24. The annular support or wire guide 16 is positioned above bushing 12 adjacent to bushing top 22. As shown in FIG. 2, annular support member 16 is a ring like member having a circular internal opening 32 and a plurality of recesses 34 at spaced intervals around the outer periphery thereof. Recesses 34 are spaced apart by partially circular segments 36 of the support member's periphery. Recesses 34 are shown as partially circular or somewhat broadly U-shaped recesses in the outer peripheral portion of the member. Recesses 34 are sufficiently broad enough around the support member perimeter to accommodate both sides of a single U-shaped wire 14. The recesses are also of a sufficient depth to accommodate at least a significant portion of the wire within the recess. When the swab cup 10 is being assembled, the cage or internal components thereof are assembled first. Initially, the wires are positioned with their lower end portions 28 within the apertures of bushing lower lip 18. Annular support or wire guide 16 is positioned on bushing 12 at its top 22 and wires 14 are positioned within recesses 34 and aligned with the longitudinal axis of the wires in alignment with the longitudinal axis of the swab cup. Once this has been done, an endless and thin band of elastic or elastomeric material can be positioned around the outer periphery of wires 14 in a circumferentially stretched condition so as to exert a radially inwardly directed force on the wires through their mid-portion 30 in order to retain their position during handling and before the actual molding occurs. During the molding of swab cup body 24, the cage is placed in a mold cavity with the band in place. As the elastomeric material is injected into the mold, the band stays in place and assists in positioning wires 14 within recesses 34 of wire guide or annular support member 16. During this molding process, the material must flow around all surfaces of wires 14, annular support member 16 and around at least a portion of bushing 12. Because of recesses 34 in annular support member 16, wires 14 are not significantly displaced by the motion of this material flowing within the cavity of the mold around the components of the swab cup. So as a result, the wires remain essentially in the position which they assumed when the cage was assembled. Because of annular support member 16, wires 14 are retained in a regular spaced relation around the periphery of swab cup 10 so that when the swab cup is put into use, the lower portion of the swab cup will support the fluid load in an evenly distributed fashion. This construction alleviates the above noted problems with the prior art structures wherein the load was not supported evenly around the lower periphery of the swab cup. The guide ring or annular support member of this invention provides a simple structure which provides for correctly holding the wires of a swab cup in their designed and preferred locations during the molding process of the swab cup. Because the annular support member retains the wires in this regularly spaced location arrangement around the periphery of the swab cup, it provides a positive assurance that the wires will be positioned for the maximum effectiveness of the swab cup.

A well swab cup has an annular bushing for supporting a plurality of longitudinally extending reinforcing members within an elastomeric cup like body. The reinforcing members are supported around the periphery of the bushing and extend upward to a mid-portion of the body. A reinforcing member position support assembly is located above the bushing within the body to locate and position the reinforcing members in a spaced relation to each other around the swab cup.

BACKGROUND OF THE INVENTION This invention relates to an improved method and apparatus for recovery of metal, particularly aluminum, from dross which has been skimmed from a reverberatory or electric furnace. Aluminum dross is a combination of aluminum metal, various oxides, nitrates and carbides and constitutes a by-product of an aluminum melting operation. Generally the dross floats on the top of the molten aluminum metal in the furnace. The dross can contain anywhere from 30% to 90% aluminum depending upon the particular processing technique and type of furnace. Dross, therefore, in an aluminum melting operation includes a significant amount of aluminum metal which is considered a valuable resource and which desirably must be recovered. Heretofore a typical dross recovery system for aluminum melting called for spreading and cooling the dross on a floor surface, for example, an aluminum floor surface. Because this cooling process is rather slow, a great deal of the aluminum metal in the dross is lost due to a thermite reaction, i.e., exothermic oxidation of aluminum metal. Typically 2% of the aluminum metal is lost for each minute of cooling. Thus, a dross which initially has about 70% aluminum metal will decrease to about 40% to 60% aluminum metal after cooling because of losses due to a thermite reaction. To separate the aluminum metal from cooled and solidified dross, one must next crush and break the dross into an aggregate. The aggregate is then further broken down in a conventional ball mill. At each of these stages a certain amount of the aluminum is lost as dust. Ultimately the dross concentrate is processed in a conventional rotary salt furnace which permits the aluminum metal to separate from the remaining dross material. Further metal losses are observed as a result of the furnace operation due to additional thermite reaction. Also there is loss due to formation of slag or dross in the salt furnace. Ultimately the recovery of aluminum by this process is on the order of 40% to 50% of the original aluminum metal in the dross. Consequently a method and mechanism for improving the recovery of aluminum metal as well as other metals from their dross will have a significant commercial and conservation impact. A technique for recovery of zinc metal from a dross concentrate is disclosed in Ross et al, U.S. Pat. No. 4,057,232. Ross discloses a method for separating molten zinc from dross by use of a press mechanism which compresses the dross in a ladle and squeezes the free metal through openings in the ladle. This concept of using compression to separate free metal from a molten mixture is also taught in Howard, U.S. Pat. No. 563,769, with repect to separation of the noble metal, silver, from lead bullion. Osborn, in U.S. Pat. No. 2,278,135, discloses a dross press for removing antimony from tin, for example. Kuwano et al, U.S. Pat. No. 4,003,559, teaches an agitating device which is designed to squeeze free metallic zinc from dross. In Kuwano et al, the dross is violently stirred in order to effect the separation of the free metal from the dross. So far as applicants can determine, however, there are no prior art references or practices which utilize compression techniques or apparatus for the separation of aluminum from dross. The present invention therefore contemplates a method of improving aluminum metal recovery from dross and the special apparatus necessary to effect such improved recovery. The invention also may be applied to the recovery of brass and copper from appropriate dross. SUMMARY OF THE INVENTION To practice the present invention, a special tray comprising multiple parallel troughs is positioned adjacent an aluminum melting or holding furnace to collect dross from that furnace. Upon withdrawal of the dross from the furnace and placement thereof in the tray, aluminum begins to flow through openings in each trough and into a collection pan. As soon as the troughs are filled with dross, the dross is compressed. This causes additional aluminum metal to flow from the dross through openings in the tray and into the collection pan. During the compression operation, the dross is quickly cooled to thereby diminish thermite or oxidation reactions. Compression also causes small droplets of aluminum dispersed throughout the dross to coalesce into large plates at the surface of the dross. The cooled dross material is then preferably screened to remove aluminum oxide dust. Subsequently the aggregate left from the screening operation is shot blasted, tumbled and then mechanically separated into a large size aggregate, which is substantially pure aluminum, and a remaining smaller aggregate which contains a majority of aluminum but must be subjected to special melting practices for maximum aluminum recovery. The large size concentrate may be immediately recycled through a common aluminum melting furnace. The smaller size concentrate is treated in a special vortex melting furnace. The addition of flux to the vortex furnace enhances separation of the entrapped oxides from the aluminum. A nitrogen-argon gas mixture may also be injected into the vortex furnace to enhance separation of aluminum oxide. Utilizing the procedures and apparatus of the present invention, it is possible to effect recovery of 90% to 95% aluminum metal from a dross. Thus, it is an object of the present invention to provide an improved method for recovery of aluminum metal from dross. A further object of the present invention is to provide a special apparatus to collect and process dross from an aluminum furnace and to effect improved aluminum metal recovery from the dross. Another object of the invention is to provide a method of aluminum metal recovery from aluminum furnace dross which utilizes compression forces to effect decanting of the aluminum metal from the dross. Still a further object of the invention is to provide a method for treatment of dross from an aluminum furnace in which a significant portion of aluminum may be decanted by compression forces from the dross and an equally significant amount of aluminum may be mechanically separated from dross which has been compressed, cooled and mechanically separated into at least two size categories. A further object of the present invention is to provide an aluminum metal recovery process which includes a special vortex melting furnace that processes dross having a large concentration of aluminum therein by melting the aluminum and permitting flotation of the dross on top of the aluminum bath. Still a further object of the present invention is to provide an economical way of recovering a maximum amount of aluminum metal from an aluminum dross material. Another object of the invention is to promote quick cooling of aluminum dross upon removal from a furnace by separating the dross in a plurality of troughs. A further object of the invention is to promote quick cooling of aluminum dross upon removal from a furnace by compressing the dross with a ram that serves as a heat sink and as a means to restrict access of oxygen to the aluminum in the dross. A further object of the invention is to apply compressive forces on the dross and thereby effect coalescing of droplets of aluminum into plates at the surface of the dross. Another object of the invention is to provide a process for recovery of metal from dross which has the aforesaid objects and advantages and which is useful for recovery of aluminum, copper, brass and other metals from their respective dross. These and other objects, advantages and features of the invention will be set forth in greater detail in the description which follows. BRIEF DESCRIPTION OF THE DRAWING In the detailed drawing which follows, reference will be made to the drawing comprised of the following figures: FIG. 1 is a diagramatic flow chart representing the process steps practiced in the prior art to effect aluminum recovery from an aluminum dross material; FIG. 2 is a diagramatic flow chart of the sequential steps of the improved method of the present invention for aluminum recovery from dross; FIG. 3 is an exploded perspective view of the assembly of the special troughs, decanting pan and compression mechanism for removing aluminum metal from dross; FIG. 4 is a side elevation of the troughs shown in FIG. 3; FIG. 5 is a top plan view of the troughs of FIG. 4; FIG. 6 is a front elevation of the decanting pan associated with the trough of FIGS. 4 and 5; FIG. 7 is a top plan view of the pan of FIG. 6; FIG. 8 is a side elevation of the compression head associated with the assembly shown in FIG. 3; FIG. 9 is a top plan view of the head of FIG. 8; FIG. 10 is a cross sectional side view of an embodiment of the improved vortex melting furnace for effecting dross separation and aluminum recovery; and FIG. 11 is a top plan view of the furnace shown in FIG. 10. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a diagramatic view illustrating the steps of a prior art method for aluminum metal recovery from the dross taken from an aluminum melting or holding furnace. Typically, dross 14 is withdrawn from an aluminum furnace 10 and spread and cooled on a floor 12. The floor 12 is generally made from a heat sink material, for example, aluminum. During the cooling of the dross, a thermite or oxidizing reaction occurs between the aluminum metal in the dross 14 and the impurities in the dross as well as the oxygen in the air. Thus, a dross 14 which includes approximately 70% free aluminum metal when removed from the furnace 10 may drop in aluminum metal content to between 40% and 60% aluminum. As the cooling of the dross 14 is delayed, the percent of aluminum metal decreases further and the amount of aluminum metal which can be recovered from the dross 14 also decreases. After the dross 14 is cooled, it is fed into a crusher 16. The crusher 16 breaks the dross 14 into a granulate material. A certain amount of the aluminum metal in the dross 14 is lost as a dust which separates from the granulate due to the crushing operation. The granulate, though, is then fed into a ball mill 18 for further pulverization. Again, there is some loss due to dust formation in the ball mill 18. The material from the ball mill will generally include aluminum metal in an amount of 60% to 65% of the content of the granulate or dross concentrate. This material is fed into a rotary salt furnace 20 of the type known in the art, and a pound of salt is generally added to the furnace 20 along with every pound of dross concentrate charged due to the relatively low amount of aluminum in the concentrate. A certain amount of aluminum metal is lost due to a thermite reaction in the salt furnace 20. Some aluminum metal is also lost in the slag which is a by-product from the salt furnace 20 melting step. Also, disposal of the slag is a waste disposal problem due to environmental concerns. Ultimately, however, aluminum metal is withdrawn from the salt furnace 20 and poured into a mold 21 for further use. The amount of recovery of aluminum metal using this process generally will amount to about 50% or less of the aluminum metal available in the original dross 14 where the original dross 14 was comprised of approximately 70% by weight aluminum metal. This recovery is deemed insufficient and for this reason improved methods and apparatus for extracting aluminum metal from dross were sought. FIG. 2 and the remaining figures illustrate the improved method and apparatus of the present invention as applied to recovery of aluminum and which has been found to increase recovery of free aluminum metal from dross to more than 90%. Referring therefore to FIG. 2, dross 14 is withdrawn from the melting or holding furnace 10 and is immediately directed into a tray and pan collector 22 which is maintained adjacent the furnace 10. In this manner there is a quick transfer of dross 14 from the furnace 10 to the collector 22. This immediate transfer tends to diminish thermite reaction. The collector 22 is comprised of a compression tray 24 mounted on a decanting pan 26, and a separate compression wedge mechanism 28 complementary with the tray 24. The collector 22 is appropriately sized for cooperation with each particular furnace. Initially, without dross compression, some aluminum metal will drain or decant through passages or openings 25 in the walls of the troughs 43 forming the tray 24 and a bottom slot 45 and flow into the pan 26. Openings 25 are preferably vertical passages through walls 44, 46. After the tray 24 is filled with dross 14, the ram or wedge mechanism 28 is impinged against the dross 14 to compact the dross 14 and effect further transfer of aluminum metal from the dross 14 through the openings 25 into the pan 26. Compression by this mechanism is preferably effected above a threshold pressure which is determined empirically and is dependent upon the amount of free aluminum metal in the dross, the trough size and material, trough shape, dross temperature and other physical parameters of the system. The compression causes pooling of the aluminum metal in the dross 14 and migration of the metal pools to the edge surfaces of the dross 14. This is followed by quick cooling of the dross 14 and prompt solidification of the dross 14 thereby further diminishing thermite reactions and loss of aluminum due to such reactions. With the completion of this compression step, there is approximately a 50% aluminum metal recovery. Thus, the initial compression step provides for aluminum metal recovery which generally exceeds the total recovery associated with the described prior art process. Moreover, the compression step enhances the subsequent steps and aluminum recovery by causing quick solidification and pooling of large regions of aluminum metal near the edges or surfaces of the dross material. Experiments have shown, for example, that dross removed from an aluminum reverberatory furnace in the range of 1300° F. to 1600° F. must be compressed within twenty (20) minutes of removal from the furnace. Otherwise, the dross will cool and solidify. A minumum or threshold pressure of about 64 p.s.i. has been found necessary to cause coalescing of aluminum in the desired manner. This may vary depending upon the factors previously mentioned. As a next step, the solidified dross 14 is transferred to a screening device 32 as shown in FIG. 2 where the large components of the dross 14 are separated from the loose oxide dust of the dross 14 and the dross 14 is agitated and broken into manageable parts. About 20% of the dross is removed by this screening process as dust. The material removed is generally an aluminum oxide dust. Very little or no aluminum metal is, however, lost by the screening process. The remaining dross material which includes free aluminum metal mixed in with various oxides, nitrides and the like is then transferred to a blaster and separator system 34. The blaster and separator system 34 performs a number of functions including further breaking of the dross, cleaning the larger portions of dross material, and separting the larger sizes of the dross material from the remainder of the dross material. These larger components or portions are generally aluminum metal or globules of material which are at least 95% aluminum metal. Thus, the separator system 34 is designed to separate items having a general size of greater than 7 cms. (3 inches) mean diameter from the remaining dross material. This larger size material is generally 95% to 98% pure aluminum metal and may be recharged back into the furnace 10. The remaining smaller size constituent or concentrate from the dross 14 contains from 85% to 90% aluminum metal. Of course, again there is some dust which is formed during this procedure and approximately 20% of the dross material is removed as dust. Very little or no free aluminum metal is removed as dust. Only oxides and other impurities are removed. The smaller sized concentrate or granulate is added to a vortex melting furnace 36 where a small addition of flux is also fed into the furnace 36 and melted to enhance aluminum metal separation. Importantly, because of the method of the present invention, a lesser amount of flux is required to enhance separation. This is a significant improvement over technology presently known to the inventors. Use of a vortex furnace, as described, reduces the melt loss of small particles due to melting that takes place in a non-oxidizing atmosphere and to cold changing of the furnace. A layer of skim or dross 40, will then form on top of the aluminum bath 38 due to a gas injection and flux addition. The skim 40 may then be cooled and recycled through the screen 32 for further concentration. The aluminum metal layer 38 may be withdrawn into a mold 42 and processed or recirculated through the furnace 10. A small amount of aluminum is lost due to the melting procedure in the furnace 36. However, a recovery of about 95% aluminum metal is effected by processing the original dross 14 in the manner described. This is about double the recovery rate associated with the known prior art procedure illustrated by FIG. 1. The collector 22 of the present invention is depicted in greater detail in FIGS. 3-9, and the electric vortex furnace is depicted by FIGS. 10 and 11. The compression operation is effected by use of the collector 22 as depicted in FIGS. 3-9. Specifically, the collector 22 includes the tray 24 which cooperatively sits in pan 26 and is adapted to receive compression wedge or ram mechanism 28. The tray 24 is comprised of a plurality of separate, parallel troughs 43 each defined by downwardly and inwardly inclined side walls 44 and 46 which cooperate with end walls 48 and 50. Each side wall 44 and 46 inclines inwardly and downwardly and defines a space or slot 45 between the walls 44 and 46 at the juncture or apex of the walls 44 and 46. This slot 45 can vary between 1/2 inch to 21/2 inches in width. Each inclined side wall 44 and 46 includes a plurality of preferably vertical openings 25 which are sized to permit the free flow of aluminum metal yet which prohibit or prevent the passage of dross 14. The diameter of these openings can vary between 1/2 inch and 21/2 inches. The tray 24 is fabricated to sit in a collector or decanting pan 26. Decanting pan 26 is generally rectangular and includes two bottom passages or horizontal channels 52 and 54 which are sized and spaced to receive the forks of a fork lift truck so that the entire assembly including the tray 24 as situated on the pan 26 may be moved. As shown in FIGS. 8 and 9, a complementary ram or wedge mechanism 28 comprised of separate wedge members 29 is formed to cooperate with the respective troughs 43 and compress dross material 14 that is retained in each trough 43. Compression forces aluminum metal through the openings 25 and effects aluminum metal pooling as previously described. The separate wedge members 29 are interconnected by a cross member 56 which serves to align the wedge members 29 in a proper fashion so that the members 29 may be simultaneously positioned into compressive cooperation with the troughs 43. The nose of the wedge members 29 can also be designed to have different depths of penetration into trough 20 depending on the type of dross compressed, e.g., saw tooth for reverberatory dross, smooth for electric furnace dross. The cross member 56 is mounted on a pneumatic or hydraulic plunger 57 which is positioned over the tray 24. In this manner the wedge members 29 can be driven downwardly into the troughs 43 and provide significant pressure against the dross 14. This removes aluminum metal from the dross to collect in the pan 26 and also causes aluminum metal to pool in the dross 14 particularly at the edges or surfaces of the dross. To supplement the cooling effect of wedge members 29, a coolant, generally water, may be circulated through passages or tubes in the wedge members 29. The blaster and separator system 34 may be any one of a number of blasters and separators known to those skilled in the art for impinging particulate material on an item and separating constituent solid materials into size categories. The size category separation found to be most advantageous is separation of particles having greater than 7 cm. (3 inch) mean diameter from that having less than 7 cm. (3 inch) mean diameter. The smaller sized dross concentrate from the blaster/separator system 34 is fed into the furnace 36. FIGS. 10 and 11 illustrate one embodiment of furnace 36 which is useful in the practice of the present invention. There it will be seen that a furnace 36 includes a central heating bay 62. The heating bay 62 is connected by a passage 64 to a pumping bay 66 in which a vortex metal pump 68 is positioned. The pumping bay 66 is separated from the heating bay 62 by a wall 70 under which the molten metal must be guided. The pump 68 is a molten metal pump designed to impel molten metal through a passage 71 in wall 72 and into a charging bay 74. Smaller sized concentrate from the blaster/separator system 34 is fed through a charging nozzle 76 into the charging bay 74. There the material becomes molten and an influx of molten material directed by the pump 68 will cause a vortex flow within the charging bay 74. The vortex flow will direct a flow of melted aluminum and dross through a passage 78 at the lower end of the vortex flow into a skimming bay 80 and connected heating bay 62. Aluminum metal will form a lower layer in the bay 80 and dross material 82 will float on the lower aluminum metal layer 81. Metal from the skimming bay 80 may be withdrawn under a wall 60 through passage 61 into the heating bay 62 for ultimate removal to a casting mold or the like. Dross material 82 may be skimmed for further recycling and retreatment to remove aluminum. Gas may be injected into the charging bay 74 through injector 75 to enhance separation of aluminum from dross. It is, of course, possible to vary the apparatus of the present invention by utilizing different designs for furnaces, separators, screening devices and the like. It is also possible to vary somewhat the order of the steps when performing the method of the invention. Finally, the apparatus and method of the invention is applicable to recovery of other metals such as brass or copper from their respective dross materials. The invention, therefore, is to be limited only by the following claims and their equivalents.

An improved method for recovery of metal, particularly aluminum, from metal bearing dross utilizes a trough for collection of the dross. A wedge member compresses the dross in the trough. In this manner, metal is decanted from the compressed dross and flows through slots in the bottom or passages in the walls of the trough for collection in a pan, or becomes concentrated at the edges or walls of the volume of dross. The trough and wedge members also serve to cool the dross material thereby diminishing metal loss due to thermite reaction. The compressed dross coalesces and solidifies, is broken and is mechanically separated. The larger dross components from the separation process are substantially metallic and may be recycled through the furnace. The remaining components are charged in a vortex melting furnace for the lowest possible melt loss. This also effects segregation of the remaining metal from the dross by melting the metal and allowing the dross to rise to the top of the bath. The improved method of the present invention provides for recovery of about 95% of aluminum metal from a dross which contains about 70% aluminum as compared with a recovery rate of about 50% aluminum metal utilizing a generally known prior art technique.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a Divisional of co-pending U.S. application Ser. No. 11/640,960 filed on Dec. 19, 2006, and for which priority is claimed under 35 U.S.C. §120; the entire contents of U.S. application Ser. No. 11/640,960 are hereby incorporated by reference. [0002] This non-provisional application is related to the following non-provisional applications/patents: U.S. application Ser. No. 11/640,946 filed on Dec. 19, 2006, now U.S. Pat. No. 7,907,768, titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”; and U.S. application Ser. No. 11/640,947 filed on Dec. 19, 2006, now U.S. Pat. No. 7,792,348, titled “Method and Apparatus of Using Probabilistic Atlas for Cancer Detection” which were filed concurrently with U.S. application Ser. No. 11/640,960 which is the parent of the present application; the entire contents of all of the above patent applications and patents are hereby incorporated by reference. BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention relates to a digital image processing technique, and more particularly to a method and apparatus for processing breast images and using a shape model for feature removal/positioning in breast images. [0005] 2. Description of the Related Art [0006] Mammography images are powerful tools used in diagnosis of medical problems of breasts. An important feature in mammography images is the breast shape. Clearly detected breast shapes can be used to identify breast abnormalities, such as skin retraction and skin thickening, which are characteristics of malignancy. Clear breast shapes also facilitate automatic or manual comparative analysis between mammography images. Accurate breast shapes may convey significant information relating to breast deformation, size, and shape evolution. The position of the nipple with respect to the breast can be used to detect breast abnormalities. Knowledge of the mammogram view is also important for analysis of breast images, since the mammogram view sets the direction and geometry of a breast in a mammogram image. [0007] Unclear or inaccurate breast shapes may obscure abnormal breast growth and deformation. Mammography images with unclear, unusual, or abnormal breast shapes or breast borders pose challenges when used in software applications that process and compare breast images. [0008] Due to the way the mammogram acquisition process works, the region where the breast tapers off has decreased breast contour contrast, which makes breast borders unclear and poses challenges for breast segmentation. Non-uniform background regions, tags, labels, or scratches present in mammography images may obscure the breast shape and create problems for processing of breast images. Reliable breast shape detection is further complicated by variations in anatomical shapes of breasts and medical imaging conditions. Such variations include: 1) anatomical shape variations between breasts of various people or between breasts of the same person; 2) lighting variations in breast images taken at different times; 3) pose and view changes in mammograms; 4) change in anatomical structure of breasts due to the aging of people; etc. Such breast imaging variations pose challenges for both manual identification and computer-aided analysis of breast shapes. [0009] Disclosed embodiments of this application address these and other issues by using methods and apparatuses for feature removal and positioning in breast images based on a shape modeling technique for breasts. The methods and apparatuses also use an atlas for location of features in breasts. The methods and apparatuses automatically determine views of mammograms using a shape modeling technique for breasts. The methods and apparatuses perform automatic breast segmentation, and automatically determine nipple position in breasts. The methods and apparatuses can be used for automatic detection of other features besides nipples in breasts. The methods and apparatuses can be used for feature removal, feature detection, feature positioning, and segmentation for other anatomical parts besides breasts, by using shape modeling techniques for the anatomical parts and atlases for locations of features in the anatomical parts. SUMMARY OF THE INVENTION [0010] The present invention is directed to methods and apparatuses for processing images. According to a first aspect of the present invention, an image processing method comprises: accessing digital image data representing an image including an object; accessing reference data including a shape model relating to shape variation of objects from a baseline object, the objects and the baseline object being from a class of the object; and removing from the image an element not related to the object, by representing a shape of the object using the shape model. [0011] According to a second aspect of the present invention, an image processing method comprises: accessing digital image data representing an object; accessing reference data including a shape model relating to shape variation from a baseline object shape; and determining a view of the object, the determining step including performing shape registration for the object and for a minor object of the object, by representing shapes of the object and of the minor object using the shape model, to obtain an object registered shape and a mirror object registered shape, and identifying the view by performing a comparative analysis between at least one of the shape of the object, the shape of the minor object, and the baseline object shape, and at least one of the object registered shape, the mirror object registered shape, and the baseline object shape. [0012] According to a third aspect of the present invention, an image processing method comprises: accessing digital image data representing an object; accessing reference data including a baseline object including an element, and a shape model relating to shape variation from the baseline object; and determining location of the element in the object, the determining step including generating a correspondence between a geometric part associated with the baseline object and a geometric part associated with the object, by representing a shape of the object using the shape model, to obtain a registered shape, and mapping the element from the baseline object onto the registered shape using the correspondence. [0013] According to a fourth aspect of the present invention, an image processing apparatus comprises: an image data input unit for providing digital image data representing an image including an object; a reference data unit for providing reference data including a shape model relating to shape variation of objects from a baseline object, the objects and the baseline object being from a class of the object; and a feature removal unit for removing from the image an element not related to the object, by representing a shape of the object using the shape model. [0014] According to a fifth aspect of the present invention, an image processing apparatus comprises: an image data input unit for providing digital image data representing an object; a reference data unit for providing reference data including a shape model relating to shape variation from a baseline object shape; and a view detection unit for determining a view of the object, the view detection unit determining a view by performing shape registration for the object and for a mirror object of the object, by representing shapes of the object and of the mirror object using the shape model, to obtain an object registered shape and a mirror object registered shape, and identifying the view by performing a comparative analysis between at least one of the shape of the object, the shape of the mirror object, and the baseline object shape, and at least one of the object registered shape, the mirror object registered shape, and the baseline object shape. [0015] According to a sixth aspect of the present invention, an image processing apparatus comprises: an image data input unit for providing digital image data representing an object; a reference data unit for providing reference data including a baseline object including an element, and a shape model relating to shape variation from the baseline object; and an element detection unit for determining location of the element in the object, the element detection unit determining location by generating a correspondence between a geometric part associated with the baseline object and a geometric part associated with the object, by representing a shape of the object using the shape model, to obtain a registered shape, and mapping the element from the baseline object onto the registered shape using the correspondence. BRIEF DESCRIPTION OF THE DRAWINGS [0016] Further aspects and advantages of the present invention will become apparent upon reading the following detailed description in conjunction with the accompanying drawings, in which: [0017] FIG. 1 is a general block diagram of a system including an image processing unit for feature removal/positioning according to an embodiment of the present invention; [0018] FIG. 2 is a block diagram of an image processing unit for feature removal/positioning according to an embodiment of the present invention; [0019] FIG. 3 is a flow diagram illustrating operations performed by an image processing unit for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 2 ; [0020] FIG. 4 is a block diagram of an image processing unit for nipple detection according to an embodiment of the present invention illustrated in FIG. 2 ; [0021] FIG. 5 is a flow diagram illustrating operations performed by an image operations unit included in an image processing unit for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 4 ; [0022] FIG. 6 is a flow diagram illustrating operations performed by a shape registration unit included in an image processing unit for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 4 ; [0023] FIG. 7 is a flow diagram illustrating exemplary operations performed by a feature removal and positioning unit included in an image processing unit for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 4 ; [0024] FIG. 8A illustrates an exemplary baseline breast atlas shape with identified baseline nipple position for the ML view for a shape model stored in a reference data unit; [0025] FIG. 8B illustrates exemplary deformation modes for a shape model stored in a reference data unit; [0026] FIG. 8C illustrates another set of exemplary deformation modes for a shape model stored in a reference data unit; [0027] FIG. 8D illustrates exemplary aspects of the operation of calculating a cost function by a shape registration unit for a registered shape according to an embodiment of the present invention illustrated in FIG. 6 ; [0028] FIG. 8E illustrates exemplary results of the operation of performing shape registration for breast masks by a shape registration unit according to an embodiment of the present invention illustrated in FIG. 6 ; [0029] FIG. 8F illustrates an exemplary ML view probabilistic atlas for probability of cancer in breasts stored in a reference data unit; [0030] FIG. 8G illustrates an exemplary CC view probabilistic atlas for probability of cancer in breasts stored in a reference data unit; [0031] FIG. 8H illustrates exemplary aspects of the operation of detecting nipple position for a breast image by an image processing unit for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 4 ; [0032] FIG. 8I illustrates exemplary aspects of the operation of warping a breast mask to an atlas using triangulation by a feature removal and positioning unit according to an embodiment of the present invention illustrated in FIG. 7 ; [0033] FIG. 8J illustrates exemplary aspects of the operation of bilinear interpolation according to an embodiment of the present invention illustrated in FIG. 7 ; [0034] FIG. 9 is a block diagram of an image processing unit for artifact removal and breast segmentation according to a second embodiment of the present invention illustrated in FIG. 2 ; [0035] FIG. 10A illustrates an exemplary output of an image processing unit for artifact removal and breast segmentation according to a second embodiment of the present invention illustrated in FIG. 9 ; [0036] FIG. 10B illustrates another exemplary output of an image processing unit for artifact removal and breast segmentation according to a second embodiment of the present invention illustrated in FIG. 9 ; [0037] FIG. 11 is a block diagram of an image processing unit for view detection according to a third embodiment of the present invention illustrated in FIG. 2 ; and [0038] FIG. 12 is a block diagram of an image processing unit for feature removal/positioning including a training system according to a fourth embodiment of the present invention. DETAILED DESCRIPTION [0039] Aspects of the invention are more specifically set forth in the accompanying description with reference to the appended figures. FIG. 1 is a general block diagram of a system including an image processing unit for feature removal/positioning according to an embodiment of the present invention. The system 100 illustrated in FIG. 1 includes the following components: an image input unit 28 ; an image processing unit 38 ; a display 68 ; an image output unit 58 ; a user input unit 78 ; and a printing unit 48 . Operation of the system 100 in FIG. 1 will become apparent from the following discussion. [0040] The image input unit 28 provides digital image data. Digital image data may be medical images such as mammogram images, brain scan images, X-ray images, etc. Digital image data may also be images of non-anatomical objects, images of people, etc. Image input unit 28 may be one or more of any number of devices providing digital image data derived from a radiological film, a diagnostic image, a photographic film, a digital system, etc. Such an input device may be, for example, a scanner for scanning images recorded on a film; a digital camera; a digital mammography machine; a recording medium such as a CD-R, a floppy disk, a USB drive, etc.; a database system which stores images; a network connection; an image processing system that outputs digital data, such as a computer application that processes images; etc. [0041] The image processing unit 38 receives digital image data from the image input unit 28 and performs feature removal/positioning in a manner discussed in detail below. A user, e.g., a radiology specialist at a medical facility, may view the output of image processing unit 38 , via display 68 and may input commands to the image processing unit 38 via the user input unit 78 . In the embodiment illustrated in FIG. 1 , the user input unit 78 includes a keyboard 85 and a mouse 87 , but other conventional input devices could also be used. [0042] In addition to performing feature removal/positioning in accordance with embodiments of the present invention, the image processing unit 38 may perform additional image processing functions in accordance with commands received from the user input unit 78 . The printing unit 48 receives the output of the image processing unit 38 and generates a hard copy of the processed image data. In addition or as an alternative to generating a hard copy of the output of the image processing unit 38 , the processed image data may be returned as an image file, e.g., via a portable recording medium or via a network (not shown). The output of image processing unit 38 may also be sent to image output unit 58 that performs further operations on image data for various purposes. The image output unit 58 may be a module that performs further processing of the image data; a database that collects and compares images; a database that stores and uses feature removal/positioning results received from image processing unit 38 ; etc. [0043] FIG. 2 is a block diagram of an image processing unit 38 for feature removal/positioning according to an embodiment of the present invention. As shown in FIG. 2 , the image processing unit 38 according to this embodiment includes: an image operations unit 128 ; a shape registration unit 138 ; a feature removal and positioning unit 148 ; and a reference data unit 158 . Although the various components of FIG. 2 are illustrated as discrete elements, such an illustration is for ease of explanation and it should be recognized that certain operations of the various components may be performed by the same physical device, e.g., by one or more microprocessors. [0044] Generally, the arrangement of elements for the image processing unit 38 illustrated in FIG. 2 performs preprocessing and preparation of digital image data, registration of shapes of objects from digital image data, and feature removal and positioning for objects in digital image data. Image operations unit 128 receives digital image data from image input unit 28 . Digital image data can be medical images, which may be obtained through medical imaging. Digital image data may be mammography images, brain scan images, chest X-ray images, etc. Digital image data may also be images of non-anatomical objects, images of people, etc. [0045] Operation of image processing unit 38 will be next described in the context of mammography images, for feature removal/positioning using a probabilistic atlas and/or a shape model for breasts. However, the principles of the current invention apply equally to other areas of image processing, for feature removal/positioning using a probabilistic atlas and/or a shape model for other types of objects besides breasts. [0046] Image operations unit 128 receives a set of breast images from image input unit 28 and may perform preprocessing and preparation operations on the breast images. Preprocessing and preparation operations performed by image operations unit 128 may include resizing, cropping, compression, color correction, etc., that change size and/or appearance of breast images. Image operations unit 128 may also extract breast shape information from breast images, and may store or extract information about breast images, such as views of mammograms. [0047] Image operations unit 128 sends the preprocessed breast images to shape registration unit 138 , which performs shape registration for breasts in the breast images. For shape registration, shape registration unit 138 represents breast shapes using a shape model, to obtain registered breast shapes. Shape registration unit 138 retrieves information about the shape model from reference data unit 158 , which stores parameters that define the shape model. Reference data unit 158 may also store one or more probabilistic atlases that include information about probability of breast structures at various locations inside breasts, and for various views of breasts recorded in mammograms. Breast structures recorded in probabilistic atlases may be, for example, cancer masses in breasts, benign formations in breasts, breast vessel areas, etc. [0048] Feature removal and positioning unit 148 receives registered breast shapes from shape registration unit 138 . Feature removal and positioning unit 148 retrieves data for a baseline breast image and/or data for a probabilistic atlas, from reference data unit 158 . Using retrieved data from reference data unit 158 , feature removal and positioning unit 148 performs removal of features and/or geometric positioning and processing for registered breast shapes. The output of feature removal and positioning unit 148 are breast images with identified features, and/or breast images from which certain features were removed. The output of feature removal and positioning unit 148 may also include information about locations of removed features or locations of other features of interest in breasts, information about orientation/view of breast images, etc. Feature removal and positioning unit 148 outputs breast images, together with positioning and/or feature removal information. Such output results may be output to image output unit 58 , printing unit 48 , and/or display 68 . [0049] Operation of the components included in image processing unit 38 illustrated in FIG. 2 will be next described with reference to FIG. 3 . Image operations unit 128 , shape registration unit 138 , feature removal and positioning unit 148 , and reference data unit 158 are software systems/applications. Image operations unit 128 , shape registration unit 138 , feature removal and positioning unit 148 , and reference data unit 158 may also be purpose built hardware such as FPGA, ASIC, etc. [0050] FIG. 3 is a flow diagram illustrating operations performed by an image processing unit 38 for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 2 . [0051] Image operations unit 128 receives a breast image from image input unit 28 (S 201 ). Image operations unit 128 performs preprocessing and preparation operations on the breast image (S 203 ). Preprocessing and preparation operations performed by image operations unit 128 may include resizing, cropping, compression, color correction, etc., that change size and/or appearance of breast images. Image operations unit 128 also extracts breast shape information from the breast image (S 205 ), and stores or extracts information about the view of the breast image (S 207 ). [0052] Image operations unit 128 sends the preprocessed breast image to shape registration unit 138 , which performs shape registration for the breast in the image to obtain a registered breast shape (S 209 ). For shape registration, shape registration unit 138 uses a shape model for breast shapes (S 211 ). The shape model describes how shape varies from breast to breast. The shape model is retrieved from reference data unit 158 (S 211 ). [0053] Feature removal and positioning unit 148 receives the registered breast shape from shape registration unit 138 . Feature removal and positioning unit 148 retrieves data describing a baseline breast image, which is included in the shape model, from reference data unit 158 (S 215 ). Feature removal and positioning unit 148 may also retrieve from reference data unit 158 data describing a probabilistic feature atlas (S 215 ). The probabilistic atlas includes information about probability of features at various locations inside breasts. Using the retrieved data from reference data unit 158 , feature removal and positioning unit 148 performs removal of features from the breast image and/or geometric positioning and processing for the registered breast shape (S 217 ). Feature removal and positioning unit 148 outputs the breast image with identified geometrical orientations, and/or from which certain features were removed (S 219 ). Such output results may be output to image output unit 58 , printing unit 48 , and/or display 68 . [0054] FIG. 4 is a block diagram of an image processing unit 38 A for nipple detection according to an embodiment of the present invention illustrated in FIG. 2 . As shown in FIG. 4 , the image processing unit 38 A according to this embodiment includes: an image operations unit 128 A; a shape registration unit 138 A; an atlas warping unit 340 ; a nipple detection unit 350 ; and a reference data unit 158 A. The atlas warping unit 340 and the nipple detection unit 350 are included in a feature removal and positioning unit 148 A. [0055] Image operations unit 128 A receives a set of breast images from image input unit 28 , and may perform preprocessing and preparation operations on the breast images. Preprocessing and preparation operations performed by image operations unit 128 A may include resizing, cropping, compression, color correction, etc., that change size and/or appearance of breast images. Image operations unit 128 A creates breast mask images including pixels that belong to the breasts in the breast images. Breast mask images are also called breast shape silhouettes in the current application. Breast mask images may be created, for example, by detecting breast borders or breast clusters, for the breasts shown in the breast images. Image operations unit 128 A may also store/extract information about breast images, such as views of the mammograms. [0056] Image operations unit 128 A sends the breast mask images to shape registration unit 138 A, which performs shape registration for breast mask images. For shape registration, shape registration unit 138 A describes breast mask images using a shape model, to obtain registered breast shapes. Shape registration unit 138 A retrieves information about the shape model from reference data unit 158 A, which stores parameters that define the shape model. [0057] Each mammogram view is associated with a shape model. A shape model may consist of a baseline breast atlas shape and a set of deformation modes. In one embodiment, the baseline breast atlas shape is a mean breast shape representing the average shape of a breast for a given mammogram view. Other baseline breast atlas shapes may also be used. The deformation modes define directions for deformation from contour points of breasts in the breast images, onto corresponding contour points of the breast in the baseline breast atlas shape. The shape model is obtained by training off-line, using large sets of training breast images. A baseline breast atlas shape can be obtained from the sets of training breast images. Deformation modes, describing variation of shapes of training breast images from the baseline breast atlas shape, are also obtained during training. Details on generation of a breast shape model using sets of training breast images can be found in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0058] A baseline breast atlas shape is generated during off-line training from a large number of training breast mask images. The baseline breast atlas shape may be, for example, a mean breast shape obtained by aligning centers of mass of training breast mask images. The alignment of centers of mass of training breast mask images results in a probabilistic map in which the brighter a pixel is, the more likely it is for the pixel to appear in a training breast mask image. A probability threshold may be applied to the probabilistic map, to obtain a mean breast shape in which every pixel has a high probability of appearing in a training breast mask image. Hence, the baseline breast atlas shape illustrates a baseline breast. Additional details regarding generation of a baseline breast atlas shape/mean breast shape can be found in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. The baseline breast atlas shape also includes a baseline nipple for the baseline breast. The baseline nipple position is identified in the baseline breast atlas shape during off-line training. [0059] To extract deformation modes for a shape model, training breast mask images are warped onto the baseline breast atlas shape during off-line training, to define parameterization of breast shape. Control points may be placed along the edges of the baseline breast atlas shape. A deformation grid is generated using the control points. Using the deformation grid, the control points are warped onto training breast mask images. Shape representations for the training breast mask images are generated by the corresponding warped control points, together with centers of mass of the shapes defined by the warped control points. Additional details about generating shape representations for training breast images can be found in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0060] Principal modes of deformation between training breast mask images and the baseline breast atlas shape may be determined using the shape representations for the training breast mask images. Principal modes of deformation can be found using Principal Components Analysis (PCA) techniques. The principal components obtained from PCA represent modes of deformation between training breast mask images and the baseline breast atlas shape. Additional details regarding extraction of deformation modes are found in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0061] The baseline breast atlas shape, and the modes of deformation between training breast mask images and the baseline breast atlas shape define a shape model. Shape models can be obtained during off-line training, for each mammogram view. Shape models are stored in reference data unit 158 A. [0062] A new breast mask shape received from image operations unit 128 A may then be represented using a shape model from reference data unit 158 A. A breast mask shape may be expressed as a function of the baseline breast atlas shape, which may be a mean breast shape (B a ) in an exemplary embodiment, and of the shape model deformation modes, as: [0000] Breast   Shape = p + B a + ∑ i = 1 k  α i  L i ( 1 ) [0000] where p is an offset (such as a 2D offset) to the mean breast shape B a to account for a rigid translation of the entire shape, L i , i=1 . . . k is the set of deformation modes of the shape model, and α i , i=1 . . . k are a set of parameters that define the deviations of Breast Shape from the mean breast shape along the axes associated with the principal deformation modes. The parameters α i , i=1 . . . k are specific to each breast mask. Hence, an arbitrary breast mask may be expressed as a sum of the fixed mean breast shape (B a ), a linear combination of fixed deformation modes L i multiplied by coefficients α i , and a 2D offset p. Details on how a mean breast shape/baseline breast atlas shape B a and deformation modes L i , i=1 . . . k are obtained during training, using training breast images can be found in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0063] Each mammogram view v i is associated with a mean breast shape (B a — vi ) specific to that view, and with a set of deformation modes L i — vi , i=1 . . . k vi specific to that view. [0064] For each breast mask image B mask — new received from image operations unit 128 A, shape registration unit 138 A retrieves the mean breast shape (B a — vi ) and the set of deformation modes L i — vi , i=1 . . . k vi associated with the view v i of the breast mask image B mask — new . Shape registration unit 138 A next identifies the parameters α i , i=1 . . . k vi and the 2D offset p for the breast mask image B mask — new , to fit the breast mask image B mask — new with its correct shape representation of the form: [0000] Breast   Shape = B a  _  vi + p + ∑ i = 1 k vi  α i  L i  _  vi [0065] Atlas warping unit 340 receives the registration results for the breast mask image B mask — new from shape registration unit 138 A. Registration results for the breast mask image B mask — new include the parameters α i , i=1 . . . k vi for the breast mask image B mask — new and the functional representation [0000] Breast   Shape = B a  _  vi + p + ∑ i = 1 k vi  α i  L i _  vi [0000] for the breast mask image B mask — new . Atlas warping unit 340 then warps the breast mask image B mask — new to the mean breast shape B a vi . Atlas warping unit 340 may, alternatively, warp the breast mask image B mask — new to a probabilistic feature atlas A vi specific to the view v i of the breast mask image B mask — new . The probabilistic feature atlas data is stored in reference data unit 158 A. [0066] The probabilistic feature atlas A vi ; includes an image of the mean breast shape B a — vi for view v i , together with probabilities for presence of a feature at each pixel in the mean breast shape B a — vi . Hence, the probabilistic atlas A vi ; is a weighted pixel image, in which each pixel of the mean breast shape B a — vi is weighted by the feature probability for that pixel. [0067] The probabilistic feature atlas is obtained by training off-line, using large sets of training breast images with previously identified feature structures. Features recorded in probabilistic atlases may be cancer masses in breasts, benign formations in breasts, breast vessel areas, etc. The shapes of training breast images are represented as linear combinations of deformation modes obtained in training. Using the shape representations for the training breast images, previously identified features in the training breast images are mapped to the baseline-breast atlas shape obtained in training. By overlapping feature positions from the training images onto the baseline breast atlas shape, a probabilistic atlas containing probabilities for presence of a feature in the baseline breast atlas shape is obtained. Additional details on generation of a probabilistic atlas using sets of training breast images with previously identified features can be found in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0068] After atlas warping unit 340 warps the breast mask image B mask — new to the probabilistic atlas A vi ; or to the mean breast shape B a — vi , a warped breast mask image B mask — new — warped is obtained. Feature probability weights from the probabilistic atlas A vi are associated with pixels in the warped image B mask — new — warped . The baseline nipple position from the mean breast shape B a — vi is also associated with pixels in the warped image B mask — new — warped . [0069] Nipple detection unit 350 receives the warped breast mask image B mask — new — warped , together with shape registration information of the form [0000] Breast   Shape = B a  _  vi + p + ∑ i = 1 k vi  α i  L i _  vi , [0000] that establishes a correspondence between pixels of B mask — new — warped and pixels of B mask — new . [0070] Nipple detection unit 350 warps the B mask — new — warped image back to the original B mask — new , and an image P mask — new , is obtained. Since the baseline nipple position has been identified in the baseline breast atlas shape during off-line training, and since B mask — new — warped has the shape of the baseline breast atlas shape, the image P mask — new includes a warped nipple position from B mask — new — warped to B mask — new . Hence, the image P mask — new is an image of the breast mask image B mask — new , in which the position of the nipple has been identified. Therefore, the image P mask — new includes nipple detection results for the original breast mask B mask — new . [0071] If atlas warping unit 340 warped the breast mask image B mask — new to probabilistic atlas A vi , the image P mask — new includes feature probabilities for various breast features, at various pixel locations inside the breast mask image B mask — new . Hence, in this case, the image P mask — new is a weighted pixel image, in which each pixel of the breast mask image B mask — new is weighted by the feature probability for that pixel. If the feature is a cancer structure for example, the image P mask — new is a weighted pixel image, in which each pixel of the breast mask image B mask — new is weighted by the probability for cancer at that pixel. Additional details on mapping feature probabilities from a probabilistic atlas A vi ; to a breast mask image B mask — new to obtain a probability map for a feature in a breast mask image B mask — new can be found in the co-pending non-provisional application titled “Method and Apparatus of Using Probabilistic Atlas for Cancer Detection”, the entire contents of which are hereby incorporated by reference. [0072] The identified nipple position in image P mask — new provides very useful information for detection of the nipple and for the position of the nipple with respect to the breast. If the image P mask — new includes cancer probabilities associated with pixels of the B mask — new breast mask from a probabilistic cancer atlas, image P mask — new provides information about the nipple position with respect to probable locations of cancer masses in the B mask — new breast mask. The position of the nipple with respect to the breast can be used to detect breast abnormalities. Since the position of the nipple with respect to the breast is influenced by breast abnormalities, information about nipple position and nipple proximity to high probability cancer regions in breast help in identification of cancer masses, structural changes, breast abnormalities, etc. [0073] The initially identified nipple position in image P mask — new (and hence in breast mask image B mask — new ) can also be a starting point for performing a refinement of the nipple position. Refinement of the nipple position can be performed, for example, in regions adjacent to or including the initially identified nipple position in image P mask — new . [0074] Nipple detection unit 350 outputs the image P mask — new . The image P mask — new may be output to image output unit 58 , printing unit 48 , and/or display 68 . [0075] Image operations unit 128 A, shape registration unit 138 A, atlas warping unit 340 , nipple detection unit 350 , and reference data unit 158 A are software systems/applications. Image operations unit 128 A, shape registration unit 138 A, atlas warping unit 340 , nipple detection unit 350 , and reference data unit 158 A may also be purpose built hardware such as FPGA, ASIC, etc. [0076] FIG. 5 is a flow diagram illustrating operations performed by an image operations unit 128 A included in an image processing unit 38 A for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 4 . [0077] Image operations unit 128 A receives a raw or preprocessed breast image from image input unit 28 (S 401 ). The breast image may be retrieved by image operations unit 128 A from, for example, a breast imaging apparatus, a database of breast images, etc. Image operations unit 128 A may perform preprocessing operations on the breast image (S 403 ). Preprocessing operations may include resizing, cropping, compression, color correction, etc. [0078] Image operations unit 128 A creates a breast mask image for the breast image (S 405 ). The breast mask image includes pixels that belong to the breast. The breast mask image may be created by detecting breast borders for the breast shown in the breast image. Image operations unit 128 A may create a breast mask image by detecting breast borders using methods described in the US patent application titled “Method and Apparatus for Breast Border Detection”, application Ser. No. 11/366,495, by Daniel Russakoff and Akira Hasegawa, filed on Mar. 3, 2006, the entire contents of which are hereby incorporated by reference. With the techniques described in the “Method and Apparatus for Breast Border Detection” application, pixels in the breast image are represented in a multi-dimensional space, such as a 4-dimensional space with x-locations of pixels, y-locations of pixels, intensity value of pixels, and distance of pixels to a reference point. K-means clustering of pixels is run in the multi-dimensional space, to obtain clusters for the breast image. Cluster merging and connected components analysis are then run using relative intensity measures, brightness pixel values, and cluster size, to identify a cluster corresponding to the breast in the breast image. A set of pixels, or a mask, containing breast pixels is obtained. The set of pixels for a breast forms a breast mask B mask . [0079] Other breast border detection techniques may also be used by image operations unit 128 A to obtain a breast mask image. [0080] Image operations unit 128 A also stores information about the breast image, such as information about the view of the mammogram (S 407 ). Examples of mammogram views are MLL (medio-lateral left), MLR (medio-lateral right), CCL (cranio-caudal left), CCR (cranio-caudal right), RCC, LRR, LMLO (left medio-lateral oblique), and RMLO (right medio-lateral oblique). Image operations unit 128 A outputs the breast mask image, and information about the view of the breast image (S 409 ), to shape registration unit 138 A. [0081] FIG. 6 is a flow diagram illustrating operations performed by a shape registration unit 138 A included in an image processing unit 38 A for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 4 . [0082] Shape registration unit 138 A receives from image operations unit 128 A a preprocessed breast image, represented as a breast mask image B mask — new (S 470 ). Information about the mammogram view v i of the breast image is also received (S 470 ). Shape registration unit 138 A retrieves from reference data unit 158 A data that defines the shape model for that view, including a mean breast shape (B a — vi ) and shape model deformation modes L i — vi , i=1 . . . k vi for the view v i of the breast mask image B mask — new (S 472 ). [0083] Shape registration unit 138 A fits the breast mask image B mask — new with its correct shape representation as a linear combination of the deformation modes, [0000] Shape = B a  _  vi + p + ∑ i = 1 k vi  α i  L i _  vi , [0000] by determining parameters α i , i=1 . . . k vi and the 2D offset p. [0084] To fit the breast mask image B mask — new with its correct shape representation, shape registration unit 138 A optimizes the α i values, together with an x offset p x and a y offset p y , for a total of k+2 parameters: (p x , p y , α), where α=(α 1 , α 2 , . . . , α k ) and p=(p x , p y ) (S 478 ). For optimization, shape registration unit 138 A uses a cost function defined as the mean distance to edge. For a (p x , p y , α) parameter set, shape registration unit 138 A calculates the new shape resulting from this parameter set by formula [0000] Shape = B a  _  vi + p + ∑ i = 1 k vi  α i  L i _  vi  ( S   480 ) . [0085] The center of mass (Shape.COM) of Shape is then calculated (S 480 ). For each shape point on the exterior (border) of Shape, shape registration unit 138 A generates a ray containing the Shape.COM and the shape point, finds the intersection point of the ray with the edge of B mask — new , and calculates how far the shape point is from the intersection point obtained in this manner. This technique is further illustrated in FIG. 8D . In an alternative embodiment, the minimum distance from the shape point to the edge of B mask — new is calculated. The mean distance for the Shape points to the edges of the breast mask image B mask — new is then calculated (S 482 ). Optimized α i values and 2D offset p are selected for which the mean distance of shape points of Shape to the breast mask image B mask — new edges attains a minimum (S 484 ). [0086] Shape registration unit 138 A may use the downhill simplex method, also known as the Nelder-Mead or the amoeba algorithm (S 486 ), to fit the breast mask image B mask — new with its correct shape representation, by minimizing distances of the edge shape points of Shape to the edges of the breast mask image B mask — new . The downhill simplex method is a single-valued minimization algorithm that does not require derivatives. The downhill simplex algorithm is typically very robust. [0087] With the Nelder-Mead method, the k+2 parameters (p x , p y , α) form a simplex in a multi-dimensional space. The Nelder-Mead method minimizes the selected cost function, by moving points of the simplex to decrease the cost function. A point of the simplex may be moved by reflections against a plane generated by other simplex points, by reflection and expansion of the simplex obtained from a previous reflection, by contraction of the simplex, etc. [0088] Once parameters of the shape model are optimized for the breast mask image B mask — new , shape registration unit 138 A outputs the shape registration results for the breast mask image B mask — new to atlas warping unit 301 (S 492 ). [0089] FIG. 7 is a flow diagram illustrating exemplary operations performed by a feature removal and positioning unit 148 A included in an image processing unit 38 A for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 4 . FIG. 7 illustrates exemplary operations that may be performed by an atlas warping unit 340 and a nipple detection unit 350 included in a feature removal and positioning unit 148 A. [0090] Atlas warping unit 340 warps the registered shape for breast mask image B mask — new to a probabilistic atlas A vi , or to a baseline breast atlas shape B a — vi , associated with the view v i of the breast mask image B mask — new . Warping to probabilistic atlas A vi ; or to the baseline breast atlas shape B a — vi may be performed by triangulating the breast mask B mask — new based on its center of mass and edge points (S 501 ). After shape registration has been performed by shape registration unit 138 A, each triangle in the breast mask B mask — new corresponds to a triangle in the probabilistic atlas A vi and to a triangle in the baseline breast atlas shape B a — vi (S 503 ), as the probabilistic atlas A vi has the shape of the baseline breast atlas shape B a — vi . Pixels inside corresponding triangles of the atlas A vi (or B a — vi ) can be warped back and forth into triangles of breast mask B mask — new , using a bilinear interpolation in 2D (S 503 ). In an exemplary implementation, the bilinear interpolation in 2D may be performed by multiplying each of the triangle vertices by appropriate relative weights, as further described at FIG. 8J . [0091] Nipple detection unit 350 warps back corresponding triangles of the atlas A vi (or B a — vi ), to triangles in breast mask B mask — new (S 505 ). The nipple position for the breast mask image B mask — new is the warped nipple position from triangles of the baseline breast atlas shape B a — vi (or probabilistic atlas A vi ) to triangles of the breast mask image B mask — new (S 507 ). Hence, an image with a location for the nipple is obtained for the breast mask B mask — new (S 507 ). [0092] Feature probabilities associated with pixels in triangles of the atlas image A vi ; may become associated with pixels in triangles of breast mask B mask — new , as further described in the co-pending non-provisional application titled “Method and Apparatus of Using Probabilistic Atlas for Cancer Detection”, the entire contents of which are hereby incorporated by reference. Hence, the image with an identified nipple location may also contain feature probability values associated with image pixels, for features such as cancer structures, benign structures, etc. [0093] FIG. 8A illustrates an exemplary baseline breast atlas shape for the ML view, with identified nipple position. The exemplary baseline breast atlas shape for the ML view is included in a shape model stored in a reference data unit 158 . The baseline breast atlas shape in FIG. 8A is a mean breast shape representing the set of pixels that have 95% or more chance of appearing in a breast mask image in the ML view. The nipple N has been identified on the mean breast shape. [0094] FIG. 8B illustrates exemplary deformation modes for a shape model stored in the reference data unit 158 . The breast shape in FIG. I 510 is an exemplary baseline breast atlas shape (mean shape, in this case) for the ML view. [0095] The first 3 modes (L 1 , L 2 , L 3 ) of deformation are shown. The first mode of deformation is L 1 . Contours D 2 and D 3 define the deformation mode L 1 . The deformation mode L 1 consists of directions and proportional length of movement for each contour point from the D 2 contour to a corresponding contour point from the D 3 contour. Contours D 4 and D 5 define the second deformation mode L 2 , and contours D 6 and D 7 define the third deformation mode L 3 . [0096] The deformation modes shown in FIG. 8B may be obtained by training, using techniques described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0097] FIG. 8C illustrates another set of exemplary deformation modes for a shape model stored in the reference data unit 158 . The deformation modes shown in FIG. 8C were obtained by training a shape model using 4900 training breast images of ML view, using techniques described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. 17 deformation modes, capturing 99% of the variance in the breast images data set, were obtained. The representations of the first 4 modes L 1 , L 2 , L 3 and L 4 are shown in FIG. 8C . The representations of the first 4 modes L 1 , L 2 , L 3 and L 4 together capture 85% of the data's variance. For each mode shown in FIG. 8C , the mean breast shape (baseline breast atlas shape) for the ML view is plotted with dots (points), while the arrows represent the distance traveled by one point for that mode from −2 standard deviations to +2 standard deviations of the mean breast shape. Mode L 1 captures 52% of the variance in the breast images data set, mode L 2 captures 18% of the variance in the breast images data set, mode L 3 captures 10% of the variance in the breast images data set, and mode L 4 captures 4% of the variance in the breast images data set. The rest of the deformation modes (L 5 to L 17 ) are not shown. [0098] FIG. 8D illustrates exemplary aspects of the operation of calculating a cost function by a shape registration unit 138 A for a registered shape according to an embodiment of the present invention illustrated in FIG. 6 . Shape registration is performed for the breast mask B mask — new I 511 using an α i , i=1 . . . k parameter set and a 2D offset p. A shape bounded by contour C 512 is obtained from formula [0000] Shape = B a  _  vi + p + ∑ i = 1 k  α i  L i _  vi , [0099] where B a — vi is a mean breast shape for view v i of the breast mask B mask — new , and L i — vi , i=1 . . . k vi are shape model deformation modes. The center of mass COM for the Shape bounded by contour C 512 is found. For a point S 1 on the contour (perimeter) of Shape, a line is drawn through the COM point. The line intersects the contour of breast mask B mask — new I 511 at point S 2 . The distance to edge is the distance d between points S 1 and S 2 . Distances d are obtained for all points on the contour (perimeter) C 512 of Shape, and a cost function is obtained as the mean of all distances d. [0100] FIG. 8E illustrates exemplary results of the operation of performing shape registration for breast masks by a shape registration unit 138 A according to an embodiment of the present invention illustrated in FIG. 6 . As shown in FIG. 8E , breast masks I 513 and I 514 are fit with shape representations. The shape registration results bounded by contours C 513 and C 514 are effectively describing the shapes of breast masks I 513 and I 514 . The downhill simplex algorithm was used by shape registration unit 138 A to obtain the shape registration results shown in FIG. 8E . [0101] FIG. 8F illustrates an exemplary ML view probabilistic atlas for probability of cancer in breasts stored in the reference data unit 158 . For the ML view probabilistic atlas in FIG. 8F , the contour C 515 is the contour of the mean breast shape (baseline breast atlas shape) B a — ML for the ML view. The region R 515 A indicates the highest probability of cancer, followed by regions R 515 B, then R 515 C, and R 515 D. As shown in the probabilistic atlas, the probability for cancer is largest in the center of a breast, and decreases towards edges of the mean breast shape. [0102] FIG. 8G illustrates an exemplary CC view probabilistic atlas for probability of cancer in breasts stored in the probabilistic atlas reference data unit 158 . For the CC view probabilistic atlas in FIG. 8G , the contour C 516 is the contour of the mean breast shape for the CC view. The region R 516 A indicates the highest probability of cancer, followed by regions R 516 B, then R 516 C, and R 516 D. As shown in the probabilistic atlas, the probability for cancer is largest in the center left region of a breast, and decreases towards edges of the mean breast shape. [0103] FIG. 8H illustrates exemplary aspects of the operation of detecting nipple position for a breast image by an image processing unit 38 A for feature removal/positioning according to an embodiment of the present invention illustrated in FIG. 4 . As illustrated in FIG. 8H , a breast image I 518 is input by image operations unit 128 A. Image operations unit 128 A extracts a breast mask image I 519 for the breast image I 518 . Shape registration unit 138 A performs shape registration for the breast mask image, by representing the shape of the breast mask using a shape model. The shape registration contour C 520 fits the shape of the breast mask from image I 519 . Atlas warping unit 340 warps the breast mask registered shape I 520 to a probabilistic atlas (or alternatively to a baseline breast atlas shape) I 522 that includes a detected baseline nipple N. Atlas warping unit 340 performs warping by generating a correspondence between pixels of the breast mask registered shape I 520 and pixels of the probabilistic atlas (or of the baseline breast atlas shape) I 522 . Using the correspondence, nipple detection unit 350 warps the probabilistic atlas (or baseline breast atlas shape) I 522 onto the breast mask registered shape I 520 , hence obtaining an image I 523 with detected nipple position N′ corresponding to the baseline nipple position N, for the breast image I 518 . [0104] FIG. 8I illustrates exemplary aspects of the operation of warping a breast mask to an atlas using triangulation by a feature removal and positioning unit 148 A according to an embodiment of the present invention illustrated in FIG. 7 . [0105] Atlas warping unit 340 warps a registered shape S 530 for a breast mask image B mask — new I 530 to a probabilistic atlas A vi ; (or to a baseline breast atlas shape) A 532 shown in image I 532 . Warping to probabilistic atlas A vi ; (or to baseline breast atlas shape) A 532 is performed by triangulating the breast mask shape S 530 based on its center of mass COM_ 530 and edge points. A test point P_ 530 is used to generate a triangle in the breast mask shape S 530 . For example, a triangle T_ 530 is generated using the center of mass COM_ 530 and the test point P_ 530 and touching the edges of mask shape S 530 . The triangle is warped to probabilistic atlas A vi (or to baseline breast atlas shape) A 532 onto a corresponding triangle T_ 532 , with the COM_ 530 and the test point P_ 530 mapped to corresponding points PC_ 532 and P_ 532 . The probabilistic atlas A vi (or baseline breast atlas shape) A 532 is then warped onto registered shape S 530 by warping each triangle T_ 532 back onto the corresponding triangle T_ 530 of the breast mask B mask — new I 530 . The nipple position the probabilistic atlas A vi (or baseline breast atlas shape) A 532 is hence warped onto registered shape S 530 associated with the breast mask image B mask — new I 530 . [0106] FIG. 8J illustrates exemplary aspects of the operation of bilinear interpolation according to an embodiment of the present invention illustrated in FIG. 7 . The pixels inside corresponding triangles of the atlas A vi ; (or baseline breast atlas shape B a — vi ) can be warped back and forth to triangles in breast mask B mask — new , using a bilinear interpolation. For a correspondence between two triangles, bilinear interpolation in 2D is performed by multiplying each of the vertices by appropriate relative weights as described in FIG. 8J . Given a triangle with vertices A, B, and C, the pixel intensity at point D can be obtained as: [0000] D=A*wA/T abc +B*wB/T abc +C*wC/T abc   (2) [0000] where A, B, and C are pixel intensities at triangle vertices, T abc is the area of triangle ABC, wA is the area of triangle BCD, wB is the area of triangle ACD, and wC is the area of triangle ABD, so that T abc =wA+wB+wC. Hence, given pixels A, B, and C of a triangle inside atlas A vi (or inside B a — vi ), and corresponding pixels A′, B′, and C′ of a corresponding triangle in breast mask B mask — new , a pixel D inside triangle ABC can be warped to a pixel D′ inside triangle A′B′C′, using equation (2) in triangle A′B′C′. [0107] FIG. 9 is a block diagram of an image processing unit 38 B for artifact removal and breast segmentation according to a second embodiment of the present invention illustrated in FIG. 2 . As shown in FIG. 9 , the image processing unit 38 B according to this embodiment includes: an image operations unit 128 B; a shape registration unit 138 B; an optional atlas warping unit 340 ; an artifact removal unit 360 ; and a reference data unit 158 B. The atlas warping unit 340 and the artifact removal unit 360 are included in a feature removal and positioning unit 148 B. [0108] Image operations unit 128 B receives a breast image from image input unit 28 , and may perform preprocessing and preparation operations on the breast image. Preprocessing and preparation operations performed by image operations unit 128 B may include resizing, cropping, compression, color correction, etc., that change size and/or appearance of the breast image. Image operations unit 128 B creates a breast mask image. Breast mask images may be created, for example, by detecting breast borders or breast clusters for the breasts shown in the breast image. Image operations unit 128 B may also store/extract information about the breast image, such as view of mammogram. [0109] Image operations unit 128 B may perform preprocessing and breast mask extraction operations in a similar manner to image operations unit 128 A described in FIG. 5 . Image operations unit 128 B may create a breast mask image by detecting breast borders using methods described in the US patent application titled “Method and Apparatus for Breast Border Detection”, application Ser. No. 11/366,495, by Daniel Russakoff and Akira Hasegawa, filed on Mar. 3, 2006, the entire contents of which are hereby incorporated by reference. Other methods may also be used to create a breast mask image. [0110] Image operations unit 128 B sends the breast mask images to shape registration unit 138 B, which performs shape registration for the breast mask image. For shape registration, shape registration unit 138 B describes the breast mask image using a shape model, to obtain a registered breast shape. Shape registration unit 138 B retrieves information about the shape model from reference data unit 158 B, which stores parameters that define the shape model. [0111] The reference data unit 158 B is similar to reference data unit 158 A from FIG. 4 . Reference data unit 158 B stores shape models, and may also store probabilistic atlases for breast features. A shape model and an optional probabilistic atlas stored by reference data unit 158 B can be generated off-line, using training breast images. Details on generation of a breast shape model and a probabilistic atlas using sets of training breast images can be found in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. A shape model stored by reference data unit 158 B includes a baseline breast atlas image and a set of deformation modes. A shape model stored by reference data unit 158 B is similar to a shape model stored by reference data unit 158 A as described at FIG. 4 , with two differences. One difference is that the nipple of the baseline breast atlas shape need not be identified and marked for the baseline breast atlas shape stored by reference data unit 158 B. The second difference pertains to the method of generation of the shape model during off-line training. The training breast images used to generate the shape model for reference data unit 158 B off-line are preferably breast images without artifacts (such as tags, noise, frames, image scratches, lead markers, imaging plates, etc.), anomalies, or unusual structures. Training breast images without artifacts may be obtained by removing artifacts, anomalies, or unusual structures from the images manually or automatically, before off-line training. In that case, the baseline breast atlas shape obtained as described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference, illustrates a baseline breast without artifacts, anomalies, or unusual structures. The deformation modes obtained as described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference, describe variations between shapes of training breast images and the baseline breast atlas shape. Hence, linear combinations of the deformation modes will produce breast shapes without artifacts, anomalies, or unusual structures, because the deformation modes were obtained from training breast images that did not include artifacts, anomalies, or unusual structures. Reference data unit 158 B stores information for shape models for breasts, for various views of mammograms. [0112] Shape registration unit 138 B may perform shape registration in a manner similar to shape registration unit 138 A, as described at FIG. 6 . Optional atlas warping unit 340 receives the registration results for a breast mask image from shape registration unit 138 B, and warps the breast mask image to the baseline breast atlas shape from the shape model associated with the view of the breast mask image. Atlas warping unit 340 performs warping of breast mask images to baseline breast atlas shapes or to probabilistic atlases, as described in FIG. 4 and FIG. 7 . [0113] Using the image processing unit 38 B it is possible to remove artifacts, such as tags, noise, frames, image scratches, lead markers, imaging plates, etc., from a breast image and perform an accurate segmentation of the breast in the breast image. For a breast image I T including artifacts, image operations unit 128 B obtains a breast mask image B T — mask . Shape registration unit 138 B then performs shape registration for the breast mask image B T — mask . Shape registration unit 138 B expresses the breast mask image B T — mask as a function of the baseline breast atlas shape, which may be a mean breast shape (B a ), and shape model deformation modes, as: [0000] Breast   Shape = B a + p + ∑ i = 1 k  α i  L i , [0000] where L i , i=1 . . . k is the set of deformation modes of the shape model, α i , i=1 . . . k are a set of parameters optimized by shape registration unit 138 B for breast mask image B T — mask , and p is an offset (such as a 2D offset) to the mean breast shape B a to account for a rigid translation of the entire shape. Shape registration unit 138 B retrieves baseline breast atlas shape data and deformation modes from reference data unit 158 B. Since the shape model stored in reference data unit 158 B was generated using training breast shape images without artifacts, anomalies, or unusual structures, the Breast Shape obtained from [0000] Breast   Shape = B a + p + ∑ i = 1 k  α i  L i [0000] with optimized α i and p parameters will not include artifacts, anomalies, or unusual structures. In other words, the Breast Shape will optimize a fit to the original breast mask image B T — mask , except for the artifacts that were present in the original breast mask image B T — mask . The artifacts present in the original breast mask image B T — mask have not been learned by the shape model stored in reference data unit 158 B, and will not be fit. Hence, the Breast Shape represents a segmentation of the breast in the breast mask image B T — mask , without the artifacts may have been present in breast mask image B T — mask . [0114] Artifact removal unit 360 receives the Breast Shape together with the breast mask image B T — mask from shape registration unit 138 B, and may extract artifacts by subtracting the Breast Shape from the breast mask image B T — mask , to obtain an artifact mask image I Art [0115] Artifact removal unit 360 can then apply the artifact mask image I Art to the original breast image I T , to identify artifact positions in the original breast image I T and remove the artifacts. Artifact removal unit 360 outputs a breast image I T ′ without artifacts. [0116] If the reference data unit 158 B contains a probabilistic feature atlas, and atlas warping unit 340 is present in image processing unit 38 B, breast segmentation with artifact removal may be combined with feature detection. For example, artifact removal may be achieved for an original breast image I T together with cancer detection using a probabilistic cancer atlas and/or comparative left-right breast analysis, as described in the co-pending non-provisional application titled “Method and Apparatus of Using Probabilistic Atlas for Cancer Detection”, the entire contents of which are hereby incorporated by reference. [0117] Image operations unit 128 B, shape registration unit 138 B, optional atlas warping unit 340 , artifact removal unit 360 , and reference data unit 158 B are software systems/applications. Image operations unit 128 B, shape registration unit 138 B, optional atlas warping unit 340 , artifact removal unit 360 , and reference data unit 158 B may also be purpose built hardware such as FPGA, ASIC, etc. [0118] FIG. 10A illustrates an exemplary output of an image processing unit 38 B for artifact removal and breast segmentation according to a second embodiment of the present invention illustrated in FIG. 9 . A breast mask I 581 with a tag T 582 is segmented by image processing unit 35 B using a shape model that was constrained to remain within the shape space of typical breasts without artifacts. The final segmented breast shape 1583 obtained by image processing unit 35 B does not contain the tag T 582 , as the segmented breast shape is constrained by the shape model to resemble a breast. [0119] FIG. 10B illustrates another exemplary output of an image processing unit 38 B for artifact removal and breast segmentation according to a second embodiment of the present invention illustrated in FIG. 9 . A breast mask I 591 with a skin fold T 592 is segmented by image processing unit 35 B using a shape model that was constrained to remain within the shape space of typical breasts without artifacts. The final segmented breast shape I 593 obtained by image processing unit 35 B does not contain the skin fold T 592 , as the segmented breast shape is constrained by the shape model to resemble a breast. [0120] FIG. 11 is a block diagram of an image processing unit 38 C for view detection according to a third embodiment of the present invention illustrated in FIG. 2 . As shown in FIG. 11 , the image processing unit 38 C according to this embodiment includes: an image operations unit 128 C; a shape registration unit 138 C; a view decision unit 148 C; and a reference data unit 158 C. The view decision unit 148 C is a feature removal and positioning unit. [0121] Image operations unit 128 C receives a breast image from image input unit 28 , and may perform preprocessing and preparation operations on the breast image. Preprocessing and preparation operations performed by image operations unit 128 C may include resizing, cropping, compression, color correction, etc., that change size and/or appearance of the breast image. Image operations unit 128 C creates a breast mask image. Breast mask images may be created, for example, by detecting breast borders or breast clusters for the breasts shown in the breast image. Image operations unit 128 C may also store/extract information about the breast image, such as view of mammogram. [0122] Image operations unit 128 C may perform preprocessing and breast mask extraction operations in a similar manner to image operations unit 128 A described in FIG. 5 . Image operations unit 128 C may create a breast mask image by detecting breast borders using methods described in the US patent application titled “Method and Apparatus for Breast Border Detection”, application Ser. No. 11/366,495, by Daniel Russakoff and Akira Hasegawa, filed on Mar. 3, 2006, the entire contents of which are hereby incorporated by reference. [0123] Image operations unit 128 C sends the breast mask images to shape registration unit 138 C, which performs shape registration for the breast mask image. For shape registration, shape registration unit 138 C describes the breast mask image using a shape model, to obtain a registered breast shape. Shape registration unit 138 C retrieves information about the shape model from reference data unit 158 C, which stores parameters that define the shape model. [0124] The reference data unit 158 C is similar to reference data unit 158 A from FIG. 4 . The reference data unit 158 C stores shape models, and may also store probabilistic atlases. [0125] A shape model stored by reference data unit 158 C can be generated off-line, using training breast images. Details on generation of a breast shape model using sets of training breast images can be found in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. A shape model stored by reference data unit 158 C includes a baseline breast atlas image and a set of deformation modes. [0126] Shape registration unit 138 C may perform shape registration in a manner similar to shape registration unit 138 A, as described at FIG. 6 . Shape registration unit 138 C receives from image operations unit 128 C a breast mask image B mask of unknown mammogram view. B mask could be, for example, an ML mammogram view for which the view direction of left or right is not known. [0127] Shape registration unit 138 C fits the breast mask image B mask to a shape model M associated with one of left or right views, and obtains a registered image R 1 . Shape registration unit 138 C then flips the breast mask image B mask about a vertical axis to obtain a flipped breast mask B mask — Flipped , and then fits the flipped breast mask image B mask — Flipped to the same shape model M, to obtain a registered image R 2 . [0128] View detection unit 148 C receives breast mask images B mask and B mask — Flipped , and registered images R 1 and R 2 . View detection unit 148 C then compares the fit of R 1 to B mask , and the fit of R 2 to B mask — Flipped . If the fit of R 1 to B mask is better than the fit of R 2 to B mask — Flipped , then the view associated with shape model M is the view of the breast image B mask . On the other hand, if the fit of R 2 to the B mask — Flipped is better than fit of R 1 to B mask , then the view associated with shape model M is the view of breast image B mask — Flipped . The view direction of the breast mask image B mask is hence detected. View detection results are output to printing unit 48 , display 68 , d or image output unit 58 . [0129] The view of breast mask image B mask may also be detected by comparison to a baseline shape. Let B a be the baseline breast atlas shape associated with the shape model M. View detection unit 148 C compares the differences between R 1 and B a , and the differences between R 2 and B a . If the differences between R 1 and B a are smaller than the differences between R 2 and B a , then the view associated with baseline breast atlas shape B a (and hence with shape model M) is the view of breast image B mask . On the other hand, if the differences between R 2 and B a are smaller than the differences between R 1 and B a , then the view associated with baseline breast atlas shape B a (and hence with shape model M) is the view of breast image B mask — Flipped . [0130] The view of breast mask images B mask may also be detected by direct comparison of B mask and B mask — Flipped with B a , without performing shape registration of B mask and B mask — Flipped . If the differences between B mask and B a are smaller than the differences between B mask — Flipped and B a , then the view associated with baseline breast atlas shape B a is the view of breast image B mask . On the other hand, if the differences between B mask and B a are larger than the differences between B mask — Flipped and B a , then the view associated with baseline breast atlas shape B a is the view of breast image B mask — Flipped . [0131] FIG. 12 is a block diagram of an image processing unit 39 for feature removal/positioning including a training system 772 according to a fourth embodiment of the present invention. As shown in FIG. 12 , the image processing unit 39 includes the following components: an image operations unit 620 ; a baseline shape unit 710 ; a shape parameterization unit 720 ; a deformation analysis unit 730 ; a training shape registration unit 740 ; an atlas output unit 750 ; an image operations unit 128 ; a shape registration unit 138 ; a feature removal and positioning unit 148 ; and a reference data unit 158 . Image operations unit 620 , baseline shape unit 710 , shape parameterization unit 720 , deformation analysis unit 730 , training shape registration unit 740 , and atlas output unit 750 are included in a training system 772 . Training shape registration unit 740 and atlas output unit 750 are optional, and may be included depending on the application. Image operations unit 128 , shape registration unit 138 , feature removal and positioning unit 148 , and reference data unit 158 are included in an operation system 38 . [0132] Operation of the image processing unit 39 can generally be divided into two stages: (1) training; and (2) operation for positioning and for feature removal or detection. [0133] The principles involved in the training stage have been described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. In accordance with this fourth embodiment illustrated in FIG. 12 , the image operations unit 620 , baseline shape unit 710 , shape parameterization unit 720 , deformation analysis unit 730 , training shape registration unit 740 , and atlas output unit 750 train to generate a shape model and a probabilistic feature atlas for breast shapes. The knowledge accumulated through training by training system 772 is sent to reference data unit 158 . Image operations unit 620 and shape model unit 630 trains to generate a shape model. Optional probabilistic atlas generation unit 640 trains to generate a probabilistic atlas. The shape model and the probabilistic atlas are sent and stored in reference data unit 158 . [0134] In accordance with this fourth embodiment of the present invention, the image operations unit 128 , the shape registration unit 138 , the feature removal and positioning unit 148 , and the reference data unit 158 may function in like manner to the corresponding elements of the first, second, or third embodiments illustrated in FIGS. 4 , 9 , and 11 , or as a combination of two or more of the first, second, and third embodiments illustrated in FIGS. 4 , 9 , and 11 . During regular operation of image processing unit 39 , reference data unit 158 provides reference data training knowledge to shape registration unit 138 and to feature removal and positioning unit 148 , for use in nipple detection, view detection, and artifact removal from breast images. The principles involved in the operation for nipple detection for new breast images have been described in FIGS. 4 , 5 , 6 , 7 , 8 A, 8 B, 8 C, 8 D, 8 E, 8 F, 8 G, 8 H, 8 I and 8 J. The principles involved in the operation for artifact removal from breast images have been described in FIGS. 9 , 5 , 6 , 7 , 8 A, 8 B, 8 C, 8 D, 8 E, 8 F, 8 G, 8 H, 8 I and 8 J. The principles involved in the operation for view detection for new breast images have been described in FIGS. 11 , 5 , 6 , 7 , 8 A, 8 B, 8 C, 8 D, 8 E, 8 F, 8 G, 8 H, 8 I and 8 J. [0135] During the training stage, image operations unit 620 receives a set of training breast images from image input unit 28 , performs preprocessing and preparation operations on the breast images, creates training breast mask images, and stores/extracts information about breast images, such as view of mammograms. Additional details regarding operation of image operations unit 620 are described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. Image operations unit 620 may create breast mask images by extracting breast borders using methods described in the US patent application titled “Method and Apparatus for Breast Border Detection”, application Ser. No. 11/366,495, by Daniel Russakoff and Akira Hasegawa, filed on Mar. 3, 2006, the entire contents of which are hereby incorporated by reference. Other breast border detection techniques can also be used by image operations unit 620 to obtain shape mask images for breast images. [0136] Baseline shape unit 710 receives training breast mask images from image operations unit 620 , and generates a baseline breast atlas shape such as, for example, a mean breast shape, from the training breast mask images. Baseline shape unit 710 may align the centers of mass of the training breast mask images. The alignment of centers of mass of training breast mask images results in a probabilistic map in which the brighter a pixel is, the more likely it is for the pixel to appear in a training breast mask image. A probability threshold may then be applied to the probabilistic map, to obtain a baseline breast atlas shape, such as, for example, a mean breast shape. Additional details regarding operation of baseline shape unit 710 are described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0137] Shape parameterization unit 720 receives the training breast mask images and the baseline breast atlas shape, and warps the training breast mask images onto the baseline breast atlas shape, to define parameterization of breast shape. Shape parameterization unit 720 may use shape parameterization techniques adapted from “Automatic Generation of Shape Models Using Nonrigid Registration with a Single Segmented Template Mesh” by G. Heitz, T. Rohlfing and C. Maurer, Proceedings of Vision, Modeling and Visualization, 2004, the entire contents of which are hereby incorporated by reference. Control points may be placed along the edges of the baseline breast atlas shape. A deformation grid is generated using the control points. Using the deformation grid, the control points are warped onto training breast mask images. Shape information for training breast mask images is then given by the corresponding warped control points together with centers of mass of the shapes defined by the warped control points. Warping of control points from the baseline breast atlas shape onto training breast mask images may be performed by non-rigid registration, with B-splines transformations used to define warps from baseline breast atlas shape to training breast mask images. Shape parameterization unit 720 may perform non-rigid registration using techniques discussed in “Automatic Construction of 3-D Statistical Deformation Models of the Brain Using Nonrigid Registration”, by D. Rueckert, A. Frangi and J. Schnabel, IEEE Transactions on Medical Imaging, 22(8), p. 1014-1025, August 2003, the entire contents of which are hereby incorporated by reference. Shape parameterization unit 720 outputs shape representations for training breast mask images. Additional details regarding operation of shape parameterization unit 720 are described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0138] Deformation analysis unit 730 uses breast shape parameterization results to learn a shape model that describes how shape varies from breast to breast. Using representations of shape for the training breast mask images, deformation analysis unit 730 finds the principal modes of deformation between the training breast mask images and the baseline breast atlas shape. Deformation analysis unit 730 may use Principal Components Analysis (PCA) techniques to find the principal modes of deformation. The principal components obtained from PCA represent modes of deformation between training breast mask images and the baseline breast atlas shape. Additional details regarding operation of deformation analysis unit 730 are described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0139] The baseline breast atlas shape and the modes of deformation between training breast mask images and the baseline breast atlas shape, define a shape model. A shape model can be obtained for each mammogram view. Shape model information is sent to reference data unit 158 , to be used during operation of image processing unit 39 . [0140] Training shape registration unit 740 receives data that defines the shape model. Training shape registration unit 740 then fits training breast mask images with their correct shape representations, which are linear combinations of the principal modes of shape variation. Shape registration unit 740 may use the downhill simplex method, also known as the Nelder-Mead or the amoeba algorithm, to optimize parameters of the shape model for each training breast mask image in the training dataset, and optimally describe training breast mask images using the shape model. Additional details regarding operation of training shape registration unit 740 are described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0141] Atlas output unit 750 receives from training shape registration unit 740 the results of shape registration for the set of training breast mask images analyzed. The set of training breast mask images have features that have been previously localized. Features could be cancer structures, benign structures, vessel areas, etc. Using shape registration results, the localized features in the training breast mask images are mapped from the training breast mask images onto the baseline breast atlas shape. An atlas is created with locations of the features in the baseline breast atlas shape. Since a large number of training breast mask images with previously localized features are used, the atlas is a probabilistic atlas that gives the probability for feature presence at each pixel inside the baseline breast atlas shape. One probabilistic atlas may be generated for each mammogram view. The probabilistic feature atlases for various breast views are sent to reference data unit 158 , to be used during operation of image processing unit 39 . Additional details regarding operation of atlas output unit 750 are described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference. [0142] Image operations unit 620 , baseline shape unit 710 , shape parameterization unit 720 , deformation analysis unit 730 , training shape registration unit 740 , atlas output unit 750 , image operations unit 128 , shape registration unit 138 , feature removal and positioning unit 148 , and probabilistic atlas reference unit 158 are software systems/applications. Image operations unit 620 , baseline shape unit 710 , shape parameterization unit 720 , deformation analysis unit 730 , training shape registration unit 740 , atlas output unit 750 , image operations unit 128 , shape registration unit 138 , feature removal and positioning unit 148 , and probabilistic atlas reference unit 158 may also be purpose built hardware such as FPGA, ASIC, etc. [0143] Methods and apparatuses disclosed in this application can be used for breast segmentation, artifact removal, mammogram view identification, nipple detection, etc. Methods and apparatuses disclosed in this application can be combined with methods and apparatuses disclosed in the co-pending non-provisional application titled “Method and Apparatus of Using Probabilistic Atlas for Cancer Detection”, the entire contents of which are hereby incorporated by reference, to perforin breast segmentation, artifact removal, mammogram view identification, nipple detection, together with cancer detection for mammography images. Shape models and probabilistic atlases generated using techniques described in the co-pending non-provisional application titled “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, the entire contents of which are hereby incorporated by reference, can be used for breast segmentation, artifact removal, mammogram view identification, nipple detection, and cancer detection. Additional applications, such as temporal subtraction between breast images can be implemented using methods and apparatuses disclosed in this application, and methods and apparatuses disclosed in “Method and Apparatus of Using Probabilistic Atlas for Cancer Detection”. [0144] The methods and apparatuses disclosed in this application can be used for automatic detection of other features besides nipples in breasts. The methods and apparatuses can be used for feature removal, feature detection, feature positioning, and segmentation for other anatomical parts besides breasts, by using shape modeling techniques for the anatomical parts and atlases for locations of features in the anatomical parts. The methods and apparatuses disclosed in this application can be coupled with methods and apparatuses from “Method and Apparatus of Using Probabilistic Atlas for Cancer Detection” using shape models and probabilistic atlases generated as described in “Method and Apparatus for Probabilistic Atlas Based on Shape Modeling Technique”, to perform feature removal, feature detection, feature positioning, and object segmentation for other objects and anatomical objects besides breasts, and other features besides cancer structures or breast features. [0145] Although detailed embodiments and implementations of the present invention have been described above, it should be apparent that various modifications are possible without departing from the spirit and scope of the present invention.

Methods and apparatuses process images. The method according to one embodiment accesses digital image data representing an image including an object; accesses reference data including a shape model relating to shape variation of objects from a baseline object, the objects and the baseline object being from a class of the object; and removes from the image an element not related to the object, by representing a shape of the object using the shape model.

CROSS REFERENCE TO PRIOR APPLICATIONS [0001] This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2010/066613, filed on Nov. 2, 2010 and which claims benefit to German Patent Application No. 10 2009 053 428.8, filed on Nov. 19, 2009. The International Application was published in German on May 26, 2011 as WO 2011/061051 A1 under PCT Article 21(2). FIELD [0002] The present invention provides a positioning device for converting a rotary motion into a linear motion comprising a drive unit generating a torque, a drive shaft on which an eccentric is arranged, an output shaft arranged at the eccentric and movable in a slot of a coupling member, and an adjusting element connected with the coupling element and supported so that the adjusting element is adapted to be moved linearly together with the coupling element. BACKGROUND [0003] Such positioning devices are used in particular to drive exhaust gas recirculation valves, but they may also be used in waste gate valves, butterfly valves or as VNT actuators. [0004] Various valves with positioning devices or similar positioning devices are known, wherein an electric motor serves as the drive unit whose drive shaft is coupled with eccentrics of various types, the motion of the eccentrics being converted, via different coupling mechanisms, into a linear motion of a valve rod serving as an adjusting element. [0005] EP 1 319 879 A1 describes a valve driven by an electric motor, wherein an output shaft is arranged eccentrically with respect to a drive shaft, a roller being provided rotatably on the output shaft and traveling in a slot of a coupling element. The roller is spring-biased in one direction. The traveling path of the coupling element slot provided for the roller is perpendicular to the direction of movement of the coupling element. The development of the force-stroke curve of this element is thus fixed. [0006] DE 102 21 711 A1 describes a similar valve wherein two eccentrics are coupled with each other. In this design, the slot that serves as a traveling path for a ball bearing is also designed as a straight line that extends perpendicularly to the direction of movement. It is again not possible to provide special required force-stroke curves during the actuation of the valve with sufficient variability. [0007] A valve driven by an electric motor is also described in EP 1 378 655 A2, wherein a rotating member comprises two opposite slots in which a rod is guided which in turn is connected with a valve rod. The slot may here be configured as a defined curve. With this design, it is possible to set a defined effort for the adjustment of the valve as a direct function of the stroke. The required structural space is rather large, as is the number of components needed. SUMMARY [0008] An aspect of the present invention is to provide a positioning device which allows the selection of a force-stroke curve or a rotational angle-stroke curve for specific applications and which at the same time requires as little space as possible. [0009] In an embodiment, the present invention provides a positioning device for converting a rotary motion into a linear motion which includes a drive unit configured to generate a torque, a drive shaft on which an eccentric is arranged, a coupling element comprising a slot, an output shaft arranged at the eccentric. The output shaft is configured to move in the slot of the coupling element. An adjusting element is connected with the coupling element. The adjusting element is supported so as to be linearly movable with the coupling element. The slot comprises a guide path configured to cooperate with the eccentric which comprises an angle with a plane perpendicular to a direction of movement of the adjusting element. Due of the previously unknown interaction of an eccentric drive and a slot curve path, it is possible for the first time, and to a much larger extent than before, to set force-stroke curves rotational angle-stroke curves that allow for an adjustment of such a positioning device to a number of different applications. The structural space is thereby not larger than with other known eccentric drives. With the same total stroke, the length of the eccentric may be chosen to be even smaller. BRIEF DESCRIPTION OF THE DRAWINGS [0010] The present invention is described in greater detail below on the basis of embodiments and of the drawings in which: [0011] FIG. 1 shows a perspective view of the coupling device and the eccentric of a positioning device according to prior art; [0012] FIGS. 2 a ) and b ) shows the coupling device and the eccentric of a positioning device of the present invention at the respective end positions; [0013] FIG. 3 shows the function of linear stroke over an angle of rotation for a positioning device with a coupling device of FIG. 2 in graphic representation; and [0014] FIG. 4 shows the function of force over stroke for a positioning device with a coupling device of FIG. 2 in a graphic representation, compared with the corresponding function of a plane slot. DETAILED DESCRIPTION [0015] In an embodiment of the present invention, the slot can, for example, describe a curve with a varying pitch. This provides additional possibilities for the adjustment of force-stroke curves to specific applications. [0016] In an embodiment of the present invention, a roller or a bearing can, for example, be arranged on the output shaft, which travels in the slot so that friction between the slot or its traveling path and the outer path of the rolling body, i.e. the bearing or the roller in the present instance, is minimized. [0017] In an embodiment of the present invention, the initial position of the rotation for the actuation of the adjusting element can, for example, be a position which, seen in the direction of rotation, is situated before a dead center existing for the axial movement of the output shaft, which dead center is passed during the rotational movement to the end position. It thus becomes possible to realize short strokes of a valve with rather large actuating angles, which allows for an exact proportioning in the sensitive adjustment range shortly after leaving the closed position. [0018] In an embodiment of the present invention, a first portion of the slot to be traveled by the output shaft can, for example, have an upward slope with respect to the plane perpendicular to the direction of movement of the adjusting element, while a second portion to be traveled can, for example, have a downward slope. With such a design, a further adaptation of the relationship between the angle of rotation and the resulting stroke can be obtained as well as an adaptation to a desired force-stroke characteristic which may lead, for example, to a largely constant effort for the adjustment in the first portion. At the same time, such an adaptation allows for an additional reduction outside an upstream transmission. [0019] In an embodiment of the present invention, the upward slope in the first portion to be traveled can, for example, be steeper than the upward slope of a rolling line of the output shaft when traveling through the portion from a first end position to the top dead center, seen with respect to the axial movement of the output shaft. It is thereby provided that a stroke occurs in this adjustment region. [0020] The can thus be kept constant in a significant region about at least one of the two end stops. The available adjustment force thereby becomes independent of tolerances that could occur, for example, as a result of a thermal expansion of the valve rod. Such an almost constant force curve in the region of the closed position for about 15-25% of the full stroke is required in particular in case of the application of the positioning device as an actuator of a waste gate valve, because of the prevailing gas pressure forces at the gate. [0021] A positioning device is thus provided whose coupling device, in combination with the eccentric, leads to the possibility of a selectable force-stroke setting by appropriately adjusting the selected rotational angle range with respect to the slot. The present positioning device also allows an adjustment between the angle of rotation and the stroke for a better proportioning. The required structural space is at the same time kept very small. [0022] An embodiment of the positioning device of the present invention is illustrated in the drawings and will hereinafter be described. [0023] FIG. 1 illustrates a detail of a positioning device corresponding to the prior art. The part here illustrated is the part of the positioning device essential to the present invention. [0024] As is known per se, the positioning device comprises a non-illustrated rotary drive unit such as, for example, an electric motor, which drives a drive shaft 2 . On the end of the drive shaft 2 opposite the drive unit, an eccentric 4 is provided in a manner secured against rotation. At the end of the eccentric 4 remote from the drive shaft 2 , an output shaft 6 is provided that extends parallel to the drive shaft 2 so that the output shaft 6 rotates in a circular manner about the drive shaft 2 when the drive shaft 2 is rotated. [0025] A ball bearing 8 is arranged at the end of the output shaft 6 opposite the eccentric 4 , the inner race thereof being fastened on the output shaft 6 . An outer race 10 of the ball bearing 8 moves in a slot 12 of a coupling element 14 to which an adjusting element 16 in the form of a valve rod of a globe valve not illustrated in detail herein. The valve rod is supported in a housing in a manner known per se so that it can only perform a linear stroke movement with the coupling element. In the coupling device 14 illustrated, the slot 12 is an opening limited in height by two limiting walls 17 , 18 whose mutual distance substantially corresponds to the circumference of the ball bearing 8 and whose width is determined by the length of the eccentric 4 and by the adjustment angle thereof. The limiting walls 17 , 18 that serve as the guide path 20 of the ball bearing 8 are designed as straight planes that extend perpendicularly to the direction of movement of the valve rod 8 when the drive unit is operated. [0026] In comparison with the above, the slot 12 according to the present invention, or the resulting guide track 20 , illustrated in FIG. 2 is designed as a curve. A curve in the sense of the present application is thus a line that is not necessarily completely linear. [0027] This curve is designed so that a positioning device of this type is suitable, for example, to drive a waste gate valve. With such a valve, it is desired that, when leaving the closed position of the valve, the valve force remains approximately constant over a certain opening range. [0028] In FIG. 2 , the eccentric 4 is only indicated as a connecting line between the fulcrum of the eccentric 4 and the pivot point 6 of the bearing 8 or a roller. FIG. 2 a ) illustrates the coupling element 14 in a position in which the adjusting element 16 is in a first end position that is defined, for example, by correspondingly formed stops for upstream gears or other movable parts. In this position, the bearing 8 is located at the left end of the slot 12 below a dead center 24 of the eccentric 4 that is the top dead center with respect to the axial movement of the pivot point 6 . [0029] If, hereafter, the drive unit is operated clockwise and the eccentric is thereby rotated clockwise, the bearing 8 is rotated at a constant distance around the rotational axis of the drive shaft 2 and rolls along the guide path 20 of the slot 12 that is only movable in the vertical direction. A first part of the slot 12 travelled by the rolling of the bearing 8 has a slope 22 with respect to a plane vertical to the actuation direction of the adjusting element, which slope is steeper than the respective circular arc traveled by the bearing. Despite the upward movement of the be aring, this causes a downward movement of the slot 12 and thus of the coupling element 14 and the adjusting element 16 . The part of the guide path 20 following after the top dead center 24 has been passed first has a lesser upward slope 22 that eventually passes into a downward slope in a second part 26 . FIG. 2 b ) illustrates the second end position reached after both parts 22 , 26 have been passed. [0030] The stroke resulting from this movement is plotted in FIG. 3 over the rotational angle. It is evident that the resulting graph 28 is rather flat in the first part and is significantly steeper as the stroke becomes larger. Such a curve is advantageous, since it is drastically facilitates volume flow control, because in the part just after opening a small change in the stroke results in a rather significant change in the volume flow, whereas, with a rather large stroke, a change in stroke only results in rather small changes in the volume flow. [0031] In FIG. 4 the graph 30 illustrates the force-stroke curve of a positioning device according to FIG. 2 , whereas the dotted graph 32 represents the force-stroke curve of a positioning device with a guide path perpendicular to the movement direction of the adjusting element as illustrated in FIG. 1 . In a range of up to about 4 mm of stroke, corresponding to about 25% of the total stroke, the valve force to be applied by a positioning device of FIG. 2 , contrary to the valve force to be applied by a positioning device of FIG. 1 , only changes slightly with the stroke. [0032] Besides this advantage of setting a desired force curve, it is also possible to realize additional reductions and transmissions with respect to the entire adjustment range by using the slot to increase or reduce the adjusting path of the adjusting element relative to the length of stroke of the output shaft. [0033] Additional structural space can be saved in this manner. The positioning device of the present invention allows adjusting both force-stroke curves and rotational angle-stroke curves depending on the respective application, so that such a positioning device can be used in many different applications, basically without resulting in a larger required structural space as compared with known positioning devices. [0034] The scope of protection of the claims is not restricted to the embodiment described, different forms of the guide path may be desired depending on the application, in order to achieve the advantageous force-stroke curve. It is also possible to design such a positioning device to act in the opposite direction.

A positioning device for converting a rotary motion into a linear motion includes a drive unit configured to generate a torque, a drive shaft on which an eccentric is arranged, a coupling element comprising a slot, an output shaft arranged at the eccentric. The output shaft is configured to move in the slot of the coupling element. An adjusting element is connected with the coupling element. The adjusting element is supported so as to be linearly movable with the coupling element. The slot comprises a guide path configured to cooperate with the eccentric which comprises an angle with a plane perpendicular to a direction of movement of the adjusting element.

FIELD AND BACKGROUND OF INVENTION [0001] Recent advances in high volume server computer systems, typically rack mounted systems, have introduced advanced processors and operating systems capable of addressing significantly larger volumes of memory. Additionally, the advanced processors can in some models be fabricated with two or more processors on a die or on a common carrier and supported in a single socket, increasing the power and thermal demands placed on systems. [0002] Rack optimized server systems typically have mechanical elements, such as the enclosure for the electronic elements, based on a incremental height of 1.75 inches, known to the industry as 1 U or 1 unit. The 1 U server is the one most impacted by the advances in processors, operating systems and memory. Users who stress their 1 U systems to maximum performance for extended periods of time will encounter thermal difficulties. In order to achieve the levels of performance desired while maintaining acceptable thermal limits, such users may find it necessary to replace their 1 U servers with 2 U servers, as prior to the present invention all rack mounted servers known to the inventors were incremented in height by the standard unit. SUMMARY OF THE INVENTION [0003] With the foregoing in mind, it is a purpose of this invention to provide a solution which enables a user desiring a 1 U server to obtain such a product while providing an improvement path which enables steps upward between the 1 U and 2 U embodiments. In realizing this purpose of this invention, an enclosure for a rack mounted server is assembled using upper and lower housings which are adjustable one relative to the other to provide increases in enclosure height by fractional increments of 1 U. By providing for fractional growth in height, a user is enabled to upgrade processor and memory without the necessity of replacing the entirety of a server system which is in use. BRIEF DESCRIPTION OF DRAWINGS [0004] Some of the purposes of the invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which: [0005] FIG. 1 is a perspective view of a rack mounted device embodying the present invention; [0006] FIGS. 2A, 2B and 2 C are schematic end elevation views, from the front, of the device of FIG. 1 showing expansion of the housing from a collapsed position ( FIG. 2A ) to first and second expanded positions (FIGS. 2 B and 2 C); and [0007] FIGS. 3A, 3B and 3 C are schematic side elevation views, from the right, of the device of FIGS. 1 and 2 showing expansion of the housing from a collapsed position ( FIG. 3A ) to first and second expanded positions ( FIGS. 3B and 3C ). DETAILED DESCRIPTION OF INVENTION [0008] While the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the present invention is shown, it is to be understood at the outset of the description which follows that persons of skill in the appropriate arts may modify the invention here described while still achieving the favorable results of the invention. Accordingly, the description which follows is to be understood as being a broad, teaching disclosure directed to persons of skill in the appropriate arts, and not as limiting upon the present invention. [0009] Referring now more particularly to the accompanying drawings, FIG. 1 illustrates one example of a rack and a rack mounted enclosure for a digital data processing element. Most commonly, the processing element is a server computer system, configured with a printed circuit board known as a motherboard and sockets which accept other boards or cards which mount processors, memory and input/output (I/O) adapters. However, the processing elements may have other functions than server computer systems, such as telecommunications switches or the like. The present invention contemplates that the mechanical enclosures here disclosed may serve to enclose electrical elements of a wide variety of types and utilities. [0010] A rack mounted complex includes several enclosures (one of which is shown at 100 ), to be described more fully hereinafter. The enclosures are mounted in a rack provided by a set of spaced uprights 110 , 111 , 112 , 113 which have a series of vertically spaced holes 115 formed in them. The spacing of the uprights one from another and of the holes along them are to a standard, to accommodate enclosures of standard dimensions. Typically, a rack mount intended to be filled or partially filled with 1 U enclosures will have a spacing which is intended to limit the choice of enclosures to be mounted to those that are 1 U, posing a problem for users who may encounter the need of replacing 1 U servers. [0011] Each enclosure 100 has, as shown in FIG. 2 , an upper housing 124 and a lower housing 125 engaging the upper housing. The upper and lower housings together define the enclosure 100 for a digital data processing element as described above, the enclosure having height, predetermined width, and predetermined depth. The width and depth meet the standard for the spacing of the uprights 110 , 111 , 112 , 113 of the rack into which the enclosure is to be mounted. The upper and lower housings 124 , 125 are adjustable one relative to the other to vary the height of the enclosure from a collapsed condition toward an extended condition by defined increments. [0012] The enclosure has right and left mounting ears 126 , 127 ( FIG. 1 ) projecting widthwise from opposing sides with the mounting ears defining mounting openings of a size and spacing to align with the holes or mounting openings 115 along the uprights in a standard rack mount for electronic devices. Here, each ear 126 , 127 has at least one hole, enabling the use of fasteners to secure the enclosure in a rack mount. The spacing of the openings in the uprights defines preferred increments by which the height of the enclosure is adjusted. [0013] In the illustrated design for the enclosure mechanicals, this spacing opens the possibility of expanding the height of the enclosure by the amount of one or two hole spacings. That is, the height may be expanded by ⅓ U in each of two steps, if the full capability of the invention is exercised. It should be understood when referring to enclosures specified in increments or fractions of U that the actual enclosure dimensions should be less to maintain appropriate mechanical tolerances. Thus the enclosure may house processing elements at 1 U height ( FIG. 2A ), at 1 and ⅓ U height ( FIG. 2B ), and at 1 and ⅔ U height ( FIG. 2C ) for a standard rack with three mounting holes for each 1 U space. With this capability, secondary or daughter cards or boards or greater heights may be accommodated, enabling the installation of higher capability processors, memory and I/O adapter cards. The 1 U configuration is here referred to as the collapsed condition, with the greater height positions being referred to as expanded conditions. While described with reference to a 1 U enclosure, the invention is equally applicable to enclosures of 2 U or more. [0014] Other embodiments can support other rack standards which may exist or be developed in the future, with fewer or more than three holes per U. For rack standards with two holes per U, increments of 1 U and 1 and ½ U can be supported. For rack standards with four holes per U, increments of 1 U, 1 and ¼ U, 1 and ½ U and 1 and ¾ U can be supported. The same pattern can be extended to more holes per U. As another example, a 2 U enclosure with a rack with three holes per U could accommodate enclosures which vary by ⅓ U from 2 U to 3 and ⅔ U. A 1 U enclosure can indeed grow beyond 1 and ⅔ U and a 2 U beyond 3 and ⅔ U with an upper housing whose sides are themselves extendible or by replacing the upper housing with a taller one while retaining all other components. [0015] Returning to the preferred embodiment of the present invention, in order to provide ventilation while protecting against undesirable entry of foreign objects and materials, folding end plates 129 , 130 are mounted on the upper housing 124 . The end plates are retracted against the inner surface of the upper housing 124 when the enclosure is in the collapsed condition, by means of a pivotal connection to the housing. As the upper housing is raised relative to the lower housing to expand the enclosure, the end plates pivot downwardly to take positions shown in FIGS. 2B, 3B , 2 C and 3 C. FIGS. 2B and 3B illustrate the enclosure in the 1 and ⅓ expanded position; FIGS. C and 3 C, the 1 and ⅔ expanded position. [0016] The housings may be made in a number of ways to accommodate the expanding movement and positioning here described. Fasteners such as screws or bolts may be used to secure the housings in collapsed and expanded positions, or clips formed in the material of the housings may secure them in a tool less manner in their relative position. [0017] In the drawings and specifications there has been set forth a preferred embodiment of the invention and, although specific terms are used, the description thus given uses terminology in a generic and descriptive sense only and not for purposes of limitation.

An enclosure for a rack mounted electronic device is assembled using upper and lower housings which are adjustable one relative to the other to provide increases in enclosure height by fractional increments of a standard unit of height. By providing for fractional growth in height, a user is enabled to upgrade processor, memory and other components without the necessity of replacing the entirety of a device which is in use.

FIELD OF THE INVENTION The present invention relates to a method of and an apparatus for applying a looped rubber member onto a collapsible tire building drum, and more particularly a method of and an apparatus for transferring automatically the looped member from a looped member forming machine to a collapsible tire building drum on which tires are built and applying automatically the transferred looped member onto the collapsible collapsible tire building drum. SUMMARY OF THE INVENTION In accordance with one important aspect of the present invention, there is provided a method of applying a looped rubber member from a looped rubber forming machine onto a collapsible tire building drum having grooves formed in the periphery thereof, comprising the steps of (1) inserting at least two pairs of retaining members into the looped rubber member depending from the looped rubber forming machine in a first direction; (2) retaining the looped rubber member on the retaining members from the looped rubber forming machine; (3) rotating the retaining members with the looped rubber member retained thereon toward the collapsible tire building drum to a second direction which is opposite to the first direction; (4) forming the looped rubber member on the retaining members into a substantially circular configuration; (5) transferring the substantially circular looped rubber member toward the collapsible tire building drum into a first position in which the center of the looped rubber member is in axial alignment with the longitudinal center axis of the collapsible tire building drum; (6) further transferring the substantially circular looped rubber member from the first position into a second position in which the looped rubber member surrounds the periphery of the collapsible tire building drum radially contracted; (7) receiving the retaining members in the grooves in the periphery of the collapsible tire building drum; (8) applying the substantially circular looped rubber member onto the periphery of the collapsible tire building drum; and (9) withdrawing the retaining members from the grooves in the periphery of the collapsible tire building drum. In accordance with another important aspect of the present invention, there is provided an apparatus for applying a looped rubber member from a looped rubber forming machine onto a collapsible tire building drum having grooves formed in the periphery thereof, comprising at least two pairs of retaining members for retaining the looped rubber member thereon from the looped member forming machine; retaining member driving means having the retaining members mounted thereon and adapted for driving one pair of the retaining members of the two pairs to move toward and away from each other and the other pair of the retaining members to move angularly with respect to the one pair of the retaining members; support member for supporting the retaining member driving means thereon; support member rotating means mounted on the support member and adapted for rotating the support member about the center of the support member; carrier plate having the support member rotatably mounted thereon; carrier plate driving means having the carrier plate mounted thereon and adapted for driving the carrier plate to move vertically toward and away from the collapsible tire building drum; slide block having the carrier plate driving means mounted thereon; and slide block driving means having the slide block threadably mounted thereon and adapted for driving the slide block to move horizontally toward and away from the tire building machine. DESCRIPTION OF THE PRIOR ART Conventionally, apparatuses for taking up looped rubber members from a looped member forming machine by which the looped rubber members are manufactured have been known in Japanese publication Nos. 52-44792 and 52-44793, both of which form the basis of U.S. Pat. No. 4,039,365, issued Aug. 2, 1977. The looped rubber member retained in such taking-up apparatuses, however, can not be automatically transferred and applied onto a collapsible tire building drum on which the tires are built, and accordingly is applied on the collapsible tire building drum through an apparatus adapted for transferring the looped rubber member to the collapsible tire building drum or by operators. In the apparatuses taught in the Japanese publication Nos. 52-44792 and 52-44793, thus, the apparatus adapted for transferring the looped rubber member is further necessarily required between the taking-up apparatus and the collapsible tire building drum in order to apply the looped rubber member on the collapsible tire building drum. An apparatus has then been designed for applying the looped rubber member from the looped member forming machine onto the collapsible tire building drum. The apparatus comprises retaining means such as suction cups by means of which the looped rubber member is retained circumferentially at the outer surface thereof from the outside of the looped rubber member. This apparatus, however, is necessarily made as a large-sized construction since the looped member is retained at the outer surface thereof from the outside of the looped rubber member. Furthermore, there is another drawback in that the looped rubber member may be detached from the suction cups by the reason that the looped rubber member is attached to the suction cups by suction. It is accordingly one important of the present invention to provide a method of and an apparatus for applying automatically the looped rubber member from the looped member forming machine onto the collapsible tire building drum with the looped rubber member retained on the retaining members from the inside of the looped member. It is another important of the present invention is to provide an apparatus of a small size for applying automatically the looped rubber member from the looped member forming machine on the collapsible tire building drum. BRIEF DESCRIPTION OF THE DRAWING The features and advantages of the method of and the apparatus for applying automatically the looped rubber member from the looped member forming machine on the collapsible tire building drum in accordance with the present invention will be more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which: FIG. 1 is a plan view showing the overall arrangement and construction of the apparatus in accordance with the present invention; FIG. 2 is a side view showing the apparatus of the present invention held in an axial alignment with the looped member forming machine indicated by phantom lines and the collapsible tire building drum indicated by phantom lines on which the looped rubber member manufactured by the forming machine is to be applied through the method and the apparatus in accordance with the present invention; FIG. 3 is an end view showing the apparatus in accordance with the present invention; FIG. 4 is a view showing the looped rubber member depending from a holding plate of the looped member forming machine with retaining members of the present invention inserted into the looped rubber member, and paths of the retaining members through which the looped rubber member is to be retained on the retaining members; FIG. 5 is a view similar to FIG. 4 but shows the looped rubber member retained on the retaining members through the paths of the retaining members shown in FIG. 4; FIG. 6 is a view showing paths of the retaining members through which the looped rubber member shown in FIG. 5 is to be formed into a substantially circular configuration; FIG. 7 is a view showing the looped rubber member formed into a substantially circular configuration through the paths of the retaining members shown in FIG. 6; and FIG. 8 is a view showing the retaining members shown in FIG. 7 received in grooves in the collapsible tire building drum and the looped rubber member retained on the collapsible tire building drum which is fully radially expanded with respect to the center axis thereof. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and more particularly FIGS. 1, 2 and 3, there is shown a preferred embodiment of the looped member applying apparatus in accordance with the present invention in which a looped rubber member is automatically applied from a looped member forming machine 1 (as indicated by phantom lines in FIG. 2) onto a collapsible tire building drum 2 (as indicated by phantom lines in FIG. 2) of a tire building machine on which tires are built. The looped member forming machine 1 is axially aligned with the collapsible tire building drum 2 which is radially movable with respect to the longitudinal center axis of the collapsible tire building drum 2. The collapsible tire building drum 2 has formed on the periphery thereof four grooves 3 (FIGS. 6, 7 and 8) for receiving therein four horizontal extending rods 72, 74, 78 and 82 which will be described hereinafter as the description will proceed. Each of the grooves 3 extends parallel to the longitudinal axis of the collapsible tire building drum 2. The looped rubber member L manufactured by the looped member forming machine 1 is placed on a holding plate 1a (FIG. 4) of the looped member forming machine 1. A longitudinal extending base plate designated by reference numeral 10 is mounted on a floor 12 such that the looped member forming machine 1 is arranged in axial alignment with the collapsible tire building drum 2. The base plate 10 in turn has fixedly mounted thereon a longitudinal frame structure 14 consisting of a pair of upstanding side plates 16 and a pair of upstanding front end plate 18 and rear end plate 19. In the upper portions of the end plates 18 and 19 are fixedly received longitudinal extending guide rails 20 each of which extends in parallel relationship to the longitudinal axes of the looped member forming machine 1 and the collapsible tire building drum 2. The parallel guide rails 20 have slidably mounted thereon a slide block 22 which is threadably mounted on the threaded portions of a threaded drive shaft 24 which extends parallel to and within the parallel guide rails 20. The threaded drive shaft 24 is rotatably received at the front end portion thereof in the front end plate 18 of the frame structure 14 and at the rear end portion thereof in the rear end plate 19 of the frame structure 14. The rear end portion of the threaded drive shaft 24 protrudes from the rear end plate 19 and carries a driven sprocket gear 26 thereon. A chain drive unit such as a reversible motor 28 is also mounted on the base plate 10 and connected through the output shaft thereof to a gear reducer 30. The gear reducer 30 has an output shaft 32 carrying thereon a drive sprocket gear 34 which is drivably connected through an endless chain 36 to the driven sprocket gear 26 carried on the threaded drive shaft 24. Thus, as the reversible motor 28 is operated, the chain 36 is driven in directions to rotate the threaded drive shaft 24 clockwise or anticlockwise so that the slide block 22 threadably mounted on the threaded drive shaft 24 moves on and along the parallel guide rails 20 toward and away from the looped member forming machine 1 or the collapsible tire building drum 2. A pair of vertical guide posts designated by reference numeral 38 upstand from the slide block 22 and each of the vertical guide posts 38 has a vertical guide rod 40 slidably received in a vertical bore formed therein. Between the vertical guide posts 38 upstands a vertical air cylinder 42 which has a piston rod 44 vertically projecting from and retracting into the cylinder body of the vertical air cylinder 42. The piston rod 44 is movable vertically upwardly and downwardly with respect to the longitudinal axes of the looped member forming machine 1 and the collapsible tire building drum 2 by means of a bracket of the piston rod 44 slidably received in vertical slots 46 respectively formed in the vertical guide posts 38. A carrier plate designated by reference numeral 48 is mounted on the leading ends of the guide rods 40 and the piston rod 44 of the vertical air cylinder 42. Thus, the carrier plate 48 is movable vertically upwardly and downwardly through the vertical slots 46 in the vertical guide posts 38 in response to upward and downward movements of the piston rod 44 of the vertical air cylinder 42. On the carrier plate 48 is rotatably mounted a horizontal extending support member 50 which rotates coaxially about the center axis of the vertical air cylinder 42. The horizontal support member 50 is driven to rotate about the center thereof by means of support member rotating means such as a rotary actuator 52 and has mounted on the underside thereof a projection 51 which is brought into abutment with one of two stops 54 on the carrier plate 48 when the horizontal support member 50 is rotated through 180 degrees from an initial position thereof. Thus, the rotational range of the horizontal support member 50 is regulated to 180 degrees by means of the stops 54 which are angularly spaced 180 degrees away from each other on the carrier plate 48 with respect to the center of the carrier plate 48. On the undersides of the opposite end portions of the horizontal support member 50 are mounted a pair of first guide rods 56 and of second guide rods 58. The first guide rods 56 extend horizontally in parallel relationship to the horizontal support member 50 and have a first rotary actuator 60 slidably mounted thereon. Similarly, the guide rods 58 extend horizontally in parallel relationship to the horizontal support member 50 and have slidably mounted a second rotary actuator 62 thereon. A pair of first and second horizontal air cylinders respectively designated by reference numerals 64 and 66 are oppositely disposed on the horizontal support member 50 and synchronized with each other. The first horizontal air cylinder 64 has a piston rod 68 which is connected through a longitudinal slot 69 in the horizontal support member 50 to the first rotary actuator 60 slidably mounted on the first guide rods 56, while the second air cylinder 66 has a piston rod 70 which is connected through a longitudinal slot 71 in the horizontal support member 50 to the second rotary actuator 62 slidably mounted on the second guide rods 58. Thus, as the horizontal air cylinders 64 and 66 oppositely mounted on the horizontal support member 50 are operated, the piston rods 68 and 70 are simultaneously driven to move along the slots 69 and 70, respectively, so that the rotary actuators 60 and 62 move symmetrically on and along the guide rods 56 and 58 toward and away from each other. A first retaining member such as a first horizontal extending rod designated by reference numeral 72 is mounted coaxially on an output shaft 61 of the first rotary actuator 60 and rotatable about the center axis thereof in response to rotation of the output shaft 61. Likewise, a second retaining member such as a second horizontal extending rod designated by reference numeral 74 is mounted coaxially on an output shaft 63 of the second rotary actuator 62 and rotatable about the center axis thereof in response to rotation of the output shaft 63. The first and second horizontal extending rods 72 and 74 are substantially equal in length to each other and horizontally extend substantially parallel to each other. On the first horizontal extending rod 72 are mounted a first connecting arm 76 which connects the first horizontal extending rod 72 with a third horizontal extending rod 78. The third horizontal extending rod 78 is substantially equal in length and extends parallel to the first horizontal extending rod 72. Likewise, on the second horizontal extending rod 74 are mounted a second connecting arm 80 which connects the second horizontal extending rod 74 with a fourth horizontal extending rod 82. The fourth horizontal extending rod 82 is substantially equal in length and extends parallel to the second extending rod 74. The first and second connecting arms 76 and 80 are substantially equal in length to each other. The first and second rotary actuators 60 and 62 are simultaneously rotated about their axes in opposite directions with each other. Thus, as the first and second rotary actuators 60 and 62 are operated, the connecting arms 76 and 80 are angularly moved symmetrically with each other, in response to rotations of the first and second horizontal extending rods 72 and 74, and accordingly the horizontal rods 78 and 82 are angularly moved symmetrically with each other with respect to the first and second horizontal extending rods 72 and 74. The above-noted guide rods 56 and 58, rotary actuators 60 and 62, and air cylinders 64 and 66 as a whole constitute retaining member driving means 67 adapted for driving the first and second retaining members 72 and 74 to move toward and away from each other and the third and fourth retaining members 78 and 82 to move angularly with respect to the first and second retaining members 72 and 74. The above-noted parallel guide rails 20, slide block 22, threaded drive shaft 24, sprocket gears 26 and 34, reversible motor 28, gear reducer 30, endless chain 36 as a whole constitute slide block driving means 37 adapted for driving the slide block 22 to move horizontally toward and away from the looped member forming machine 1 or the collapsible tire building drum 2. The above-noted guide posts 38, guide rods 40 and air cylinder 42 as a whole constitute carrier member driving means 43 adapted for driving the carrier member 51 to move vertically toward and away from the looped member forming machine 1 or the collapsible tire building drum 2. Operation of the looped member applying apparatus thus constructed and arranged will be now described in detail hereinafter. The reversible motor 28 is first driven to rotate about the center axis thereof in one direction to cause the threaded drive shaft 24 to move on and along the parallel guide rails 20 in the direction through the endless chain 36. As a consequence, the slide block 22 threadably mounted on the threaded drive shaft 24 advances on and along the parallel guide rails 20 toward the looped member forming machine 1. When the horizontal extending rods 72, 74, 78 and 82 are inserted by movement of the slide block 22 into the looped rubber member L depending from the holding plate 1a of the looped member forming machine 1 as shown in FIG. 4, the reversible motor 28 is brought into a stop and accordingly the slide block 22 also stops. At this point, the horizontal extending rods 72, 74, 78 and 82 are caused to be held in advance in position as shown in FIG. 4. The first and second horizontal air cylinders 64 and 66 are then actuated to cause the piston rods 68 and 70 to project simultaneously from the cylinders 64 and 66, respectively. As the piston rods 68 and 79 move transversely outwardly away from each other with respect to path of the slide block 22, the first and second rotary actuators 60 and 62 move symmetrically on the first and second guide rods 56 and 58, respectively, away from each other. Thus, the first and second horizontal extending rods 72 and 74 respectively mounted on the first and second rotary actuators 60 and 62 are caused to move transversely outwardly away from each other to contact with the looped rubber member L as indicated by phantom lines in FIG. 4. The vertical air cylinder 42 mounted on the slide block 22 is then actuated to cause the piston rod 44 thereof to project vertically upwardly therefrom. As the piston rod 44 projects vertically upwardly, the horizontal extending rods 72, 74, 78 and 82 move together with the horizontal support member 50 vertically upwardly as indicated by phantom lines in FIG. 4. As a consequence, the first and second horizontal extending rods 72 and 74 take up the looped rubber member L from the holding plate 1a of the looped member forming machine 1 as shown in FIG. 5. The reversible motor 28 is then rotated for a second time about its axis in the opposite direction to cause the slide block 22 to move on and along the parallel guide rails 20 away from the looped member forming machine 1. As a consequence, the looped rubber member L is withdrawn from the holding plate 1a of the looped member forming machine 1. While the slide block 22 is moving from the looped member forming machine 1 toward the collapsible tire building drum 2, the rotary actuator 52 is actuated to cause the horizontal support member 50 to rotate through 180 degrees from the initial position thereof. When the horizontal support member 50 is rotated through 180 degrees, the projection 51 on the horizontal support member 50 is brought into abutment with the stop 54 on the carrier plate 48. As a consequence, the horizontal extending rods 72, 74, 78 and 82 with the looped rubber member retained thereon are faced toward the collapsible tire building drum 2. The first rotary actuator 60 is then actuated to cause the output shaft 61 thereof to rotate in one direction. At the same time, the second rotary actuator 62 is actuated to cause the output shaft 63 thereof to rotate in the other direction. The first horizontal extending rod 72 is caused to rotate about its axis in response to rotation of the output shaft 61 of the first rotary actuator 60 so that the third horizontal extending rods 78 connected through the connecting rod 76 with the first horizontal extending rod 72 is moved angularly upwardly with respect to the first horizontal extending rod 72 in the direction as indicated by phantom lines in FIG. 6. At the same time, the second horizontal extending rod 74 is caused to rotate about its axis in response to rotation of the output shaft 63 of the second rotary actuator 62 so that the fourth horizontal extending rods 82 connected through the connecting rod 80 with the second horizontal extending rod 74 is moved angularly upwardly with respect to the second horizontal extending rod 74 in the direction as indicated by phantom lines in FIG. 6. The air cylinders 64 and 66 oppositely mounted on the horizontal support member 50 are then actuated to cause the respective piston rods 68 and 70 to retract therein so that the first and second rotary actuators 60 and 62 respectively connected with the piston rods 68 and 70 move on and along guide rods 56 and 58, respectively, toward each other. As a consequence, the first and second horizontal extending rods 72 and 74 respectively connected with the first and second rotary actuator 60 and 62 are caused to move toward each other in the directions indicated by the phantom lines in FIG. 6. Thus, the horizontal extending rods 72, 74, 78 and 82 move to form the looped rubber member L into a substantially circular configuration larger in diameter than the periphery of the collapsible tire building drum 2 radially contracted as shown in FIG. 7. Each position of the horizontal extending rods 72, 74, 78 and 82 corresponds to the grooves 3 formed on the periphery of the collapsible tire building drum 2 when the collapsible tire building drum 2 is in radially fully expanded state as shown in FIG. 8. If the center of the looped rubber member L in the form of a substantially circular configuration is not axially aligned with the longitudinal center axis of the collapsible tire building drum 2, the horizontal extending rods 72, 74, 78 and 82 can be dispositioned, by moving vertically upwardly or downwardly the piston rod 44 of the vertical air cylinder 42, such that the center of the member L is brought into axial alignment with the longitudinal axis of the collapsible tire building drum 2. When the looped rubber member L is moved, in response to movement of the slide block 22, into the position in which the looped member L surrounds the periphery of the collapsible tire building drum 2 radially contracted as shown in FIG. 7, the reversible motor 28 is brought into a stop and accordingly the slide block 22 stops. The collapsible tire building drum 2 is then radially expanded with respect to the longitudinal axis thereof. When fully expanded, the collapsible tire building drum 2 receives the horizontal extending rods 72, 74, 78 and 82 in the grooves 3 in the periphery thereof and retains the looped rubber member L on the periphery thereof. The reversible motor 28 is then for a second time driven in the opposite direction so that the slide block 22 moves away from the collapsible tire building drum 2 toward the looped member forming machine 1. Thus, the horizontal extending rods 72, 74, 78 and 82 are withdrawn from the grooves 3 in the periphery of the collapsible tire building drum 2. While the slide block 22 is moving toward the looped member forming machine 1, the rotary actuator 52 is actuated to cause the horizontal support member 50 to rotate through 180 degrees. As a consequence, the horizontal extending rods 72, 74, 78 and 82 are faced toward the looped member forming machine 1. A new looped rubber member depending from the holding plate 1a of the looped member forming machine 1 is to be automatically applied onto the collapsible tire building drum 2 by repetition of the operation as described hereinbefore.

A method of applying a looped rubber member on a tire building drum having grooves formed in the periphery thereof, comprising the steps of inserting at least two pairs of retaining members into the looped rubber member in a first direction; retaining the looped rubber member on the retaining members; rotating the retaining members with the looped rubber member retained thereon toward the tire building drum to a second direction which is opposite to the first direction; forming the looped rubber member on the retaining members into a substantially circular configuration; transferring the substantially circular looped rubber member toward the tire building drum into a first position in which the center of the looped rubber member is in axial alignment with the longitudinal center axis of the tire building drum; further transferring the substantially circular looped rubber member from the first position into a second position in which the looped rubber member surrounds the periphery of the tire building drum radially contracted; receiving the retaining members in the grooves in the periphery of the tire building drum; applying the substantially circular looped rubber member on the periphery of collapsible tire building drum; and withdrawing the retaining members from the grooves in the periphery of the tire building drum.

CROSS-REFERENCE TO RELATED APPLICATIONS The present invention claims the benefit of the PCT/GB2011/000729 filed May 12, 2011, which claims priority to Ser. PT/105116 filed May 14, 2010. BACKGROUND OF THE INVENTION Tetracyclines are broad-spectrum antibiotics, indicated for use against many bacterial infections. Although widely utilized their use has been associated with intrinsic staining of human teeth (especially in children), bones, and soft tissues. This staining has been recognized as being due to an oxidation reaction. Laboratory studies have shown that the pigment formation can be induced by exposure to ultraviolet light in the presence of air. Animal studies, in rats, have established that simultaneous administration of ascorbic acid (vitamin C) with minocycline prevented staining of the teeth and bones and pigmentation of the thyroid gland (see “Bowles W H, Protection against minocycline pigment formation by ascorbic acid (vitamin C), J. Esthet. Dent. 1998; 10(4): 182-6”). In order to solve the problem of tetracycline induced staining of human teeth, bones and soft tissues; we have now developed a concept for co-administration of a tetracycline and an antioxidant by means of combining, in a particle, the tetracycline or one of its pharmaceutically acceptable salts and an antioxidant. The proportions of the tetracycline and antioxidant can be varied over a wide range and are not limited by any particular physical or chemical constraint. For example, it is envisaged that the particle may comprise from 90% w/w tetracycline/10% w/w antioxidant to 10% w/w tetracycline/90% w/w antioxidant. SUMMARY OF THE INVENTION In a broad aspect, the present invention provides a particle comprising a tetracycline and an antioxidant characterized in that the tetracycline and the antioxidant are encapsulated in a polymeric material. Preferably, the particle is a spray dried particle. In another aspect, the invention provides a method of producing a particle comprising a tetracycline and an antioxidant characterized in that the method comprises the step of encapsulation of the tetracycline and the antioxidant. Preferably, the tetracycline and the antioxidant are encapsulated in a polymeric material. In another aspect, the invention provides a pharmaceutical formulation characterized in that it comprises one or more particles according to the invention and, where necessary, one or more pharmaceutically acceptable excipients. The invention also provides a pharmaceutical formulation according to the invention for use as a medicament, for example for use in the treatment of infectious diseases. The invention also provides a method of co-administration of a tetracycline and an anti-oxidant characterized in that it comprises the administration of a pharmaceutical composition comprising a tetracycline and an antioxidant encapsulated in a polymeric material. Also provided by the invention is a method of avoiding staining of human teeth, bones, and soft tissues provoked by a tetracycline characterized in that it comprises the administration of a pharmaceutical composition comprising a tetracycline and an antioxidant encapsulated in a polymeric material. Although the effects of said method may be considered as cosmetic the method is essentially preventive in nature. The invention thus also provides the use of an antioxidant to prevent staining of human teeth, bones, and soft tissues provoked by a tetracycline. This use or method results in a cosmetic effect by preventing staining of human teeth, bones, and soft tissues provoked by a tetracycline. The antioxidant may, for example, be used in a pharmaceutical composition comprising the tetracycline, such as a composition of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 a - 1 d : Scanning electron microscopy photographs showing particles that are collapsed spheres and that the crystals of active materials are contained therein. DETAILED DESCRIPTION OF THE INVENTION In the context of the present invention, “encapsulation” refers to the coating of particles with another material. It is well known to those knowledgeable in the art that the efficiency of the encapsulation process is variable and that the coating material in some particles may not cover the total outer surface of the material in the interior of the particle. Hence particles with this reduced covering by the coating material are also considered to form part of this invention. Suitable mixing techniques can be applied to obtain an intimate mixture of the components. These mixing techniques are well known in the pharmaceutical industry. At the same time, if so desired, the particle size of the components can be adjusted using well known particle size reduction techniques, examples being milling and wet milling, especially high pressure homogeneous mixing. In a preferred aspect of this invention the micro particles are made by encapsulation of the components in a suitable polymer or other material. Processes for the encapsulation of tetracyclines forming particles are known e.g US 2004/0121003. Encapsulation agents can be chosen from any of those known from the literature, such as: Polysaccharides (e.g. starches, maltodextrines and gum arabic), Lipids (e.g. stearic acid, mono and diglycerides, among others) Proteins (e.g. gelatins, casein, soy), Polymers (e.g. hydroxypropylmethyl cellulose and its derivatives (e.g. hydroxypropylmethyl cellulose acetate succinate (HPMCAS), polymethacrylate and its derivatives, polyvinylpirrolidone and its derivatives, poliethyleneglycol and its derivatives). Melt extrusion procedures may also be applied to obtain mixing and encapsulation. The particles, wherein the tetracycline and the antioxidant are encapsulated, not only offers improved stability of the tetracycline by protection from atmospheric moisture and oxygen but delivers both components simultaneously in precise and fixed proportions. The tetracycline can be chosen from any of the compounds belonging to this class that show antibacterial activity or one of its pharmaceutically acceptable salts. Preferably the tetracycline is minocycline, doxycycline, tigecycline, tetracycline or one of their pharmaceutically acceptable salts. Particularly preferred compounds for use in the invention include doxycycline hyclate and minocycline hydrochloride. The antioxidant can be chosen from any of the compounds having antioxidant activity such as ascorbic acid (vitamin C); Tocopherols and Tocotrienols (e.g. vitamin E); Carotenes; Flavonoids (e.g. quercetin) or mixtures thereof. Preferably the antioxidant is ascorbic acid (vitamin C) or quercetin. In a preferred embodiment of this invention the particles comprise either doxycycline or minocycline as the hydrochloride or base and ascorbic acid (vitamin C) or quercetin. In addition a preferred polymer is hydropropylmethyl cellulose acetate succinate (HPMCAS). The particles may contain the tetracycline and the antioxidant in any variable molar proportions depending on the desired ratio. The particles can be produced by known physical methods (e.g. pan-coating, air-suspension coating, centrifugal or melt extrusion, vibrational nozzle or spray-drying) or chemical methods (e.g. interfacial polymerization, in-situ polymerization, matrix polymerization) or any other known method as referred to in the literature, as will be clear to those skilled in the art. In a preferred embodiment of this invention the particles are made by spray drying. The particles can be formulated with any adequate pharmaceutically acceptable excipient for oral, parenteral, topical, periodontal, pulmonary, vaginal or ophthalmic delivery. The formulated particles can be used in the treatment of any infectious disease responsive to treatment with a tetracycline, namely mucosae or skin infections such as acne or rosacea, but other infections are also treatable using this new and novel formulation, namely infections of the mouth, the ear and respiratory or urinary tracts. In a preferred embodiment of the invention the tetracycline and the antioxidant are suspended in a non-solvent, to produce a homogeneous mixture and the suspension spray dried. Dichloromethane and acetone or mixtures are preferred but other volatile solvents can be used. The resulting encapsulated material can be post dried if necessary to reduce the levels of the solvent. Suitable spray drying equipment is available commercially to carry out the spray drying. A preferred nozzle is a two fluid nozzle with a cap and diameter of 1.4 and 0.7 mm respectively, although different types of nozzles and differing dimensions can be used to obtain good results. EXAMPLES The following examples are illustrative and in no way restrict the scope of the invention. TABLE 1 Notation PSD Particle size distribution PS Particle size C_feed Feed concentration Solids content in the feed F_feed Feed flow Feed Flow rate in the spray dryer step T_in Inlet temperature Drying gas temperature at the inlet of the drying chamber T_out Outlet temperature Drying gas temperature at the outlet of the drying chamber R_atomiz Atomization ratio F_atomiz/F_feed (two fluid nozzle) Solution/Suspension Preparation The suspensions were prepared as follows: Charge the required amount of DCM/Acetone (75/25% w/w) in a flask; Add the required amount of polymer HPMCAS under stirring; Stir until complete dissolution; Suspend in the above flask the required quantity of antioxidant (Sodium Ascorbate or Quercetin) under stirring; and Suspend in the above flask the required amount of API (Minocycline HCl or Doxycycline Hyclate) TABLE 2 Materials Ex a Ex b Ex c Ex d Doxycycline hyclate g 3.0 3.5 — — Minocycline hydrochloride g — — 3.5 3.5 Sodium Ascorbate g 3.0 — — 3.5 Quercetine g — 3.5 3.5 — HPMCAS g 6.0 7.0 7.0 7.0 TOTAL SOLIDS g 12.0 14.0 14.0 14.0 Acetone g 27.0 31.5 31.5 31.5 Dichloromethane g 81.0 94.5 94.5 94.5 TOTAL SOLVENTS g 108.0 126.0 126.0 126.0 C_feed % w/w 10.0 10.0 10.0 10.0 Composition of the solid (% w/w) Doxycycline hyclate 25 25 — — Minocycline hydrochloride — — 25 25 Sodium Ascorbate 25 — — 25 Quercetine — 25 25 — HPMCAS 50 50 50 50 Composition of the solvent (% w/w) Acetone 25 25 25 25 Dichloromethane 75 75 75 75 Spray Drying A laboratory scale spray dryer was used in these trials. The unit was equipped with a two fluid nozzle, where nozzle cap and diameter were 1.4 and 0.7 mm, respectively. A high-performance cyclone was used to collect the dried product. The spray drying unit was operated with nitrogen and in single pass mode, i.e. without recirculation of the drying nitrogen. The aspirator, blowing nitrogen, was set at 100% of its capacity (flow rate at maximum capacity is approximately 40 kg/h). The flow rate of the atomization nitrogen was about 0.32 kg/h (corresponding to 20 mm in the rotameter of the equipment). Before feeding the stock solution/suspension, the spray dryer was stabilized with solvent (water). During the stabilization period, the solvent flow rate was adjusted in order to give the target outlet temperature (the inlet temperature of the drying gas was imposed through the heater set-point). After stabilization of the outlet temperature, the feed of the spray dryer was commuted from the solvent to the product solution (flow rate was then readjusted to maintain the outlet temperature in the target value). At the end of the stock solution/suspension, the feed was once more commuted to solvent, in order to rinse the feed line and to carry out a controlled shut down of the unit. Yield was calculated as the mass percentage of the dry product collected under the first cyclone in relation to the total solids in the solution/suspension fed to the spray dryer. TABLE 3 Parameters Spray drying parameters Ex a Ex b Ex c Ex d T_in ° C. 47 ± 1 45 ± 1 44 ± 1 48 ± 1 T_out ° C. 40 ± 1 39 ± 1 37 ± 1 41 ± 1 F_atomiz kg/h 0.32 0.32 0.32 0.32 F_feed kg/h 0.30 0.30 0.30 0.30 R_atomiz — 1.1 1.1 1.1 1.1 Results The microencapsulated material powder was analyzed for impurity profile of the tetracycline by HPLC (see Tables 4 and 5) and morphology by scanning electron microscopy (see FIG. 1 ). The figure shows that the particles are collapsed spheres and that the crystals of active materials are contained therein. TABLE 4 Results Ex a Ex b Related substances (6-Epidoxycycline) 0.13% 0.09% Related substances (Methacycline) 0.019% 0.013% Other impurities 0.00% 0.00% Related substances Total impurities 0.46% 0.18% TABLE 5 Results Ex c Ex d Related substances 0.12% 0.11% (7-monodemethylminocycline) Related substances 0.20% 0.20% (5a,6-anhydro minocycline) Related substances 0.78% 1.31% (4-Epiminocycline) Related substances 0.14% 0.14% NHM, N2-(methylhydroxy)-minocycline Total impurities 2.1% 2.6%

Particles containing a tetracycline or one of its pharmaceutically acceptable salts and an antioxidant, formulations containing the same and their use in the treatment of infectious diseases are described. Methods of encapsulation of a tetracycline or one of its pharmaceutically acceptable salts and an antioxidant are also disclosed.

FIELD OF THE DISCLOSURE [0001] The present disclosure relates in general to air conditioning units for controlling environmental conditions within building spaces, including air conditioning units for computer rooms, data centers (server rooms), and other building spaces intended for uses having special environmental control requirements. The disclosure relates in particular to air conditioning units adapted for installation within the building spaces served by the units. BACKGROUND [0002] Computer rooms and other building spaces intended for specialized uses often require precise control and regulation of environmental conditions such as temperature and humidity in order to ensure proper operation of equipment (such as but not limited to computers) installed in such building spaces. Cooling requirements for computer rooms are typically much greater and more stringent than for most building spaces due to the need to dissipate heat generated by the computer equipment operating in the computer rooms. Humidity control requirements are typically stringent as well, as excessive moisture in the air in a computer room can cause operational and maintenance problems with the computer equipment. [0003] Accordingly, computer rooms commonly are provided with specialized air conditioning (A/C) systems for controlling and regulating temperature and humidity. It has been common in the past for computer room A/C systems to be located outside the computer room and even outside the building housing the computer room, due to the physical size of the equipment needed to meet the A/C requirements for the computer room in question. In recent years, however, computer room air conditioning units (or “CRAC units”) have been developed that are sufficiently compact for installation within a computer room without greatly increasing the required floor area or height of the computer room. Examples of such CRAC units include chilled water or DX (direct expansion) A/C units manufactured by the Liebert® Corporation. [0004] Conventional CRAC units commonly utilize banked (i.e., angularly-oriented) cooling coils specially constructed for use in CRAC unit and arrayed in an A-frame or V-frame configuration within the unit. Airflow typically enters the unit vertically through the top or bottom of the unit and proceeds in a straight, vertical path through the filters and coils. In CRAC units of this type, the air velocity through the filters (also referred to herein as the “face velocity”) is comparatively high, which results in reduced filter performance. [0005] Another drawback of known CRAC units is that they cannot be readily adapted to use direct evaporative cooling systems using saturated evaporative media pads without increasing the size of the units so much that their use within a computer room becomes unviable or undesirable. Direct evaporative cooling systems using saturated evaporative media pads rely on gravity to allow water sprayed on top of the unit to trickle down, saturating the pad through which the airstream passing through the CRAC unit travels. Some of the water in the evaporative pad evaporates into the airstream, adiabatically cooling it. Water is collected in a sump located beneath the evaporative pad. However, this type of direct evaporative cooling system cannot be used in conventional CRAC units using a conventional vertical airflow pattern, because the evaporative media pads would have to be oriented horizontally, such that water would not be able to drain from the media by gravity into a drain pan. Moreover, the requirement for the evaporative media to be horizontally oriented for use in a CRAC unit having a vertical airflow pattern would increase the size of the unit and the floor area it requires. [0006] For the foregoing reasons, there is a need for CRAC units characterized by lower face velocities (and therefore better filter performance and efficiency) than conventional CRAC units, without increasing the physical size of the units significantly or at all. In addition, there is a need for CRAC units that can be adapted to use direct evaporative cooling media, without significant effect on the physical size of the units. BRIEF SUMMARY [0007] In general terms, the present disclosure teaches an enclosed air conditioning unit comprising a filter section and a cooling section in which the airflow path through the filter section and cooling section is substantially horizontal, with the physical size and configuration of the unit's cabinet or enclosure being essentially the same as (or smaller than) the cabinets for conventional air conditioning units having comparable or lower performance capabilities. [0008] In a first aspect, the present disclosure teaches an air conditioning unit comprising an enclosure having a first wall, a second wall opposite the first wall, and a primary air intake in an upper region of the enclosure; and an air treatment component assembly mounted within the enclosure so as to define a first chamber between the component assembly and the enclosure's first wall and a second chamber between the component assembly and the enclosure's second wall. Air entering the primary air intake from outside the enclosure will flow, in sequence, downward within the first chamber, horizontally through the component assembly into the second chamber, and downward within the second chamber toward a discharge outlet in a lower region of the enclosure. [0009] In one particular embodiment in accordance with the above-described first aspect, the air conditioning unit comprises an enclosure (cabinet) having a first wall, a second wall opposite the first wall, and a primary air intake in an upper region of the enclosure; plus an air treatment component assembly including a generally flat filter section and a generally flat cooling section. The filter section and cooling section are installed in parallel juxtaposition, and oriented vertically within the enclosure, so as to define a first chamber between the filter section and the enclosure's first wall, and a second chamber between the cooling section and the enclosure's second wall. Air entering the primary air intake from outside the enclosure will flow, in sequence, downward within the first chamber, horizontally through the filter section and the cooling section into the second chamber, and downward within the second chamber toward a discharge outlet in a lower region of the enclosure. Optionally, the air conditioning unit may include a bypass air intake through which air from outside the unit can flow downward into the second chamber. Embodiments that have a bypass air intake preferably will also have an intake damper for regulating the flow of air into the second chamber. [0010] In a second aspect, the present disclosure teaches an air conditioning unit comprising an enclosure having a first wall, a second wall opposite the first wall, and a primary air intake in a lower region of the enclosure; and an air treatment component assembly mounted within the enclosure so as to define a first chamber between the component assembly and the enclosure's first wall and a second chamber between the component assembly and the enclosure's second wall. Air entering the primary air intake from outside the enclosure will flow, in sequence, upward within the first chamber, horizontally through the component assembly into the second chamber, and upward within the second chamber toward a discharge outlet in an upper region of the enclosure. [0011] In one particular embodiment in accordance with the above-described second aspect, the air conditioning unit comprises an enclosure (cabinet) having a first wall, a second wall opposite the first wall, and a primary air intake in a lower region of the enclosure; plus an air treatment component assembly including a generally flat filter section and a generally flat cooling section. The filter section and cooling section are in parallel juxtaposition and oriented vertically within the enclosure, so as to define a first chamber between the filter section and the enclosure's first wall, and a second chamber between the cooling section and the enclosure's second wall. Air entering the primary air intake from outside the enclosure will flow, in sequence, upward within the first chamber, horizontally through the filter section and the cooling section into the second chamber, and upward within the second chamber toward a discharge outlet in an upper region of the enclosure. Optionally, the air conditioning unit may include a bypass air intake through which air from outside the unit can flow upward into the second chamber. Embodiments that have a bypass air intake preferably will also have an intake damper for regulating the flow of air into the second chamber. [0012] The first and second walls typically will be, respectively, the front and rear walls of the enclosure, such that the first chamber will be adjacent the front wall. In alternative embodiments, however, the first and second walls could be, respectively, the rear and front walls of the enclosure. BRIEF DESCRIPTION OF THE DRAWINGS [0013] Exemplary embodiments of CRAC units in accordance with the present disclosure will now be described with reference to the accompanying Figures, in which numerical references denote like parts, and in which: [0014] FIG. 1 is a schematic vertical cross-section through a prior art CRAC unit. [0015] FIG. 2 is a longitudinal vertical section through a first embodiment of a CRAC unit in accordance with the present disclosure, incorporating evaporative cooling media and a drift eliminator. [0016] FIG. 3A is a transverse vertical section through the CRAC unit shown in FIG. 2 . [0017] FIG. 3B is a transverse vertical section through a variant CRAC unit similar to the embodiment shown in FIG. 3A but with a DX cooling coil added. [0018] FIG. 4 is an enlarged vertical section through a CRAC unit as shown in FIG. 3A , in which air enters an upper region of the unit and exits from a lower region of the unit. [0019] FIG. 5 is an enlarged vertical section through a variant embodiment of the CRAC unit shown in FIGS. 3A and 4 , in which air enters a lower region of the unit and exits from a upper region of the unit. DETAILED DESCRIPTION [0020] FIG. 1 illustrates a prior art CRAC unit 10 in which airflow (denoted by flow arrows F) enters the top of the unit (either directly from the room in which the unit is installed or, alternatively, via a duct bringing air from outside the room), passes through a filtration section 12 , then through an A-frame banked cooling coil section 14 , and then is discharged into the room at the bottom of the unit by means of supply fans 16 . Drain pans 15 are provided to carry condensation off the coils 14 to a sump (not shown). [0021] FIGS. 2 and 3A illustrate the general configuration and basic components of one CRAC unit embodiment 100 in accordance with the present disclosure. CRAC unit 100 comprises an enclosure 101 which has a first wall 103 and an opposing second wall 104 , with either or both of walls 103 and 104 having access doors 102 as required for operation and maintenance. Enclosure 101 houses an assembly of air treatment equipment components which in the illustrated embodiment includes a filter section 115 and a cooling section 120 . Filter section 115 and cooling section 120 are each of substantially uniform thickness with generally flat side surfaces, and they mounted within enclosure 101 so as to be substantially parallel and closely adjacent to each other (i.e., in parallel juxtaposition) and oriented vertically within the enclosure 101 between and generally parallel to walls 102 and 103 . In the embodiment shown in FIG. 4 , this arrangement of the air treatment component assembly results in the formation of a first chamber 140 between filter section 115 and first wall 103 , and a second chamber 145 between cooling section 120 and second wall 104 . [0022] FIG. 3B shows a variant CRAC unit embodiment 150 similar to CRAC unit 100 but with a DX coil 160 added to the air treatment component assembly. [0023] FIG. 4 illustrates the airflow path through CRAC unit embodiment 100 . The airflow path through CRAC unit 150 would be similar to that shown in FIG. 4 . CRAC units 100 and 150 are “downflow” units in which airflow through the unit is from top to bottom. However, these units can be readily adapted for upflow operation, such as in the variant CRAC unit embodiment 200 shown in FIG. 5 , in which airflow through the unit is from bottom to top. [0024] In the downflow CRAC unit 100 shown in FIG. 4 , air enters a primary air intake 105 at the top of the unit, with the airflow initially being vertically downward (as denoted by airflow arrow F 1 ) within first chamber 140 , but then is diverted horizontally (as denoted by horizontal airflow arrow F 2 ) through filter section 115 and cooling section 120 . Cooling section 120 may comprise cooling coils and/or evaporative media. The use of direct evaporative cooling in a vertically-oriented CRAC unit is thus made possible by configuring the unit 100 such that the airflow pattern through the unit has a primary horizontal component F 2 as illustrated in FIG. 4 . [0025] In the embodiment shown in FIG. 4 , in which cooling section 120 includes evaporative media, CRAC unit 100 also incorporates a “drift eliminator” 125 (a term that will be well understood by persons skilled in the art) to remove any water droplets present in the airflow exiting the evaporative media, thus preventing what is known as “water carryover” from the evaporative media into the cooled air discharged from the unit. The airflow F 2 downstream of drift eliminator 125 is diverted vertically downward (as denoted by airflow arrow F 3 ) within second chamber 145 to a lower region of CRAC unit 100 , from which it is discharged into the space to be cooled. As indicated in FIG. 4 , the airflow discharge from CRAC unit 100 could be vertically downward (as denoted by airflow arrow F 4 ), or alternatively horizontal (as denoted by airflow arrow F 5 ) through the front and/or sides of the unit. Supply fans 130 propel the cooled air either directly into the space to be cooled or into connecting ductwork. [0026] Also as shown in FIG. 4 , CRAC unit 100 may optionally be provided with a bypass air intake 110 controlled by an intake damper 112 to allow a regulated downward flow of incoming air into second chamber 145 (as denoted by airflow arrow F 6 ), bypassing cooling section 120 to allow for cooling capacity modulation, by blending the downward-flowing untreated bypass airflow F 6 into the airflow F 2 exiting cooling section 120 (and drift eliminator 125 , as the case may be). Depending on the properties of the primary incoming airflow F 1 (e.g., temperature and humidity), it may not always be necessary for all supplied air to pass through cooling section 120 of CRAC unit 100 . For example, cooled air exiting cooling section 120 can be blended in suitable proportions with warmer untreated bypass air F 6 to produce an airflow supply to the room at a temperature somewhere between the temperatures of the two airflows being blended. [0027] The upflow CRAC unit embodiment 200 illustrated in FIG. 5 operates in substantially the same way as downflow CRAC unit embodiment in FIG. 4 except for the direction of airflow and correspondingly necessary modifications. In the illustrated embodiment, CRAC unit 200 comprises an enclosure 201 having first and second walls 203 and 204 (and access doors 202 ) and housing an air treatment component package comprising a filter section 115 , cooling section 120 , and drift eliminator 125 generally as in CRAC unit embodiments 100 and 150 . Similar to CRAC unit 100 shown in FIG. 4 , the arrangement of the air treatment component assembly within enclosure 201 results in the formation of a first chamber 240 between filter section 115 and first wall 203 , and a second chamber 245 between cooling section 120 and second wall 204 . [0028] A lower portion of enclosure 201 defines an intake plenum 210 having a roof structure 212 defining a primary air intake 215 through which intake air (denoted by airflow arrow F 1 ′) can flow upward into first chamber 240 within enclosure 201 to be horizontally diverted (as denoted by horizontal airflow arrow F 2 ′) through filter section 115 , cooling section 120 , and drift eliminator 125 . [0029] The airflow F 2 ′ downstream of drift eliminator 125 is diverted vertically upward (as denoted by airflow arrow F 3 ′) within second chamber 245 to an upper region of CRAC unit 200 , from which it is discharged into the space to be cooled by supply fans 130 . As indicated in FIG. 5 , the airflow discharge from CRAC unit 200 could be vertically upward (as denoted by airflow arrow F 4 ′), or alternatively horizontal (as denoted by airflow arrow F 5 ′) through the front and/or sides of the unit. [0030] Also as shown in FIG. 5 , CRAC unit 200 optionally may be provided with a bypass air intake 220 controlled by an intake damper 222 to allow a regulated upward flow of incoming air into second chamber 245 (as denoted by airflow arrow F 6 ′), bypassing cooling section 120 and flowing upward within second chamber 245 to mix with the airflow F 2 ′ exiting cooling section 120 and drift eliminator 125 . [0031] The airflow paths through the CRAC units shown in FIGS. 4 and 5 provide enhanced flexibility over prior art CRAC units and facilitate standardization of parts, thus avoiding the need for specialized components such as A-frame or V-frame coils and banked filters as in prior art CRAC units. The horizontal airflow across the internal components of the CRAC unit results in reduces face velocities across those components. Low face velocities increase filtration efficiency, prevent water carryover, reduce static pressure drop through the unit, and increase the cooling effectiveness of the cooling systems in the unit. The horizontal airflow in CRAC units in accordance with the present disclosure also allows for the use of direct evaporative cooling systems within the units using saturated evaporative media pads. [0032] CRAC units in accordance with the present disclosure can be adapted to use a variety of cooling systems, including but not limited to chilled water, DX refrigeration, and direct evaporative cooling systems. A wide range of airflows and static pressures can be accommodated. The CRAC units and associated control systems can be designed to provide reliable data center climate control while significantly reducing the electrical energy consumption of the computer room or data center's HVAC system. [0033] CRAC units in accordance with the present disclosure can be manufactured as packaged pieces of equipment, requiring a single-point electrical connection and communications connection as well as one piping connection each for water and drain for easy unit set-up on site. Outdoor air and return air can be mixed remotely via the building's ventilation system and ducted into the CRAC unit. [0034] In preferred embodiments, CRAC units as disclosed herein are controlled by dedicated, onboard PLCs (programmable logic controllers). Each CRAC unit's onboard controller controls all aspects of the unit's operation, including monitoring internal temperatures, modulating fan speed, and operation of the cooling systems. [0035] Variants of the disclosed CRAC units can be adapted in accordance with one or more options as listed below with respect to airflow configuration, air conditioning method, control type, and fan type: Flow Configuration [0036] Both downflow or upflow configurations are readily adaptable for mounting in rooms with or without raised floor systems, for example: Downflow units with an air intake in the upper section of the unit (top, front, side, or back), and an air discharge outlet in a lower region of the unit (bottom, front, side, or back). Upflow units with an air intake in the lower section of the unit (bottom, front, side, or back), and an air discharge outlet in a upper region of the unit (top, front, side, or back). Air Conditioning Method [0039] One or more air conditioning options can be used in a given CRAC unit, for example: [0040] Direct evaporative cooling—uses adiabatic evaporative cooling to cool the air stream by streaming water down an internal evaporative media pad. All components of the evaporative cooling system are provided integral to the unit. [0041] Water cooling—uses water passing through a coil in the CRAC unit to act as a cooling medium. Various cooling sources are possible, including: [0042] Chilled water using the building's chilled water system. Cooling provided by air-cooled or water-cooled chillers. [0043] Waterside economizer: water is cooled using an outdoor drycooler or indirect evaporative cooler; this can be used independently or in conjunction with a water-cooled chiller. [0044] Seawater, river water, irrigation water, or water from other natural sources can be passed through a coil to provide cooling. [0045] DX cooling—uses a refrigeration-based direct expansion (DX) coil to cool the airstream, with a rooftop condensing unit to provide heat rejection. [0046] Heating—for applications requiring specific dehumidification reheat, a heating coil can be provided to warm the airstream; heating coils may be of hot water or electric element types. CRAC Unit Control [0047] CRAC units in accordance with the present disclosure can use a variety of different control options, preferably including an onboard PLC controller capable of handling all unit functions, and optionally including any of the following: [0048] Full stand-alone unit control—all CRAC unit control is carried out by the onboard controller. Units can modulate remote dampers, control fan speed, choose modes of cooling, modulate valves, control pumps, etc. [0049] Remote automatic control—some high-level unit control is handled by a remote building management system (BMS) or by a dedicated central control system for the CRAC units. Modes of cooling and overall enable/disable functions are controlled by the external controller, as well as operating setpoints. Full CRAC unit information can be sent to the remote controller, and the remote controller is capable of controlling any part of the unit as may be desired. [0050] Constant/variable air volume—supply fans can be speed-controlled for variable-volume systems. For constant air volume operation, the speed controller is set to a constant value at the time of CRAC unit start-up. [0051] Sensors—various sensors can be provided with the CRAC unit for various control aspects. Examples of sensors include temperature, humidity, smoke detection, and water detection. [0052] Miscellaneous control options—other modes of operation such as control of external devices such as duct-mixing dampers and remote pumps, etc. Fan Types [0053] CRAC units in accordance with the present disclosure can be adapted to accommodate a variety of different required airflows and system static pressures according to the type of fans selected. For compactness of size and pressure-handling capabilities, the preferable fan type is an airfoil-blade backwards-inclined plenum fan. However, other types of fans such as forward and backward curved centrifugal scroll fans could also be used. [0054] It will be readily appreciated by those skilled in the art that various modifications to embodiments in accordance with the present disclosure may be devised without departing from the scope and teaching of the present teachings, including modifications which may use equivalent structures or materials hereafter conceived or developed. It is to be especially understood that the scope of the claims appended hereto should not be limited by any particular embodiments described and illustrated herein, but should be given the broadest interpretation consistent with the description as a whole. It is also to be understood that the substitution of a variant of a claimed element or feature, without any substantial resultant change in functionality, will not constitute a departure from the scope of the disclosure. [0055] In this patent document, any form of the word “comprise” is intended to be understood in its non-limiting sense to mean that any item following such word is included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one such element is present, unless the context clearly requires that there be one and only one such element. Any use of any form of any term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements in question, but may also extend to indirect interaction between the elements such as through secondary or intermediary structure. [0056] Relational terms such as “vertical”, “horizontal”, and “parallel”, are not intended to denote or require absolute mathematical or geometrical precision. Accordingly, such terms are to be understood as denoting or requiring substantial precision only (e.g., “substantially vertical” or “generally vertical”) unless the context clearly requires otherwise. Any use of any form of the term “typical” is to be interpreted in the sense of representative of common usage or practice, and is not to be interpreted as implying essentiality or invariability.

An enclosed air conditioning unit includes a filter section and a cooling section through which intake air passes before being discharged into a space within a building. The orientation of the filter section and cooling section is substantially vertical, and the airflow path through the filter section and the cooling section is substantially horizontal, resulting in reduced face velocities across these components, thereby increasing filtration efficiency and cooling effectiveness, while allowing the physical size and configuration of the air conditioning unit's enclosure to be the same as or smaller than the enclosures for conventional air conditioning units having comparable or lower performance.

FIELD OF INVENTION The invention relates to an apparatus and method for measuring local brain water content, perfusional pulsatile changes and the real time derivation of brain stiffness by comparison of perfusional and intracranial pressure tracings. BACKGROUND OF INVENTION Monitoring intracranial pressure (ICP) in real time in intensive care units has become an established standard of care in guiding physicians in the management of severe head injury. Treatment of head trauma increases pressure on the brain requiring monitoring intracranial pressure. This is particularly true in complicated cases of hydrocephalus as a post-craniotomy adjunct to detect brain swelling and in selected instances of brain infection and stroke. As brain swelling worsens due to the disease process, baseline pressure and waveform changes signal the need to aggressively attempt to reverse the course of the swelling with medications and pulmonary ventilation changes. Intracranial pressure monitoring is normally performed by inserting a shunt through a hole in the cranium. A ventriculostomy catheter connected to an external pressure transducer is then introduced via the shunt into the brain substance. The shunt may also be used to drain excess fluid from the brain substance. An external pressure transducer provides accurate pressure measurements since a reliable baseline may be established. However, an external pressure transducer requires invasive procedures, risking a patient's health. More recently, a miniaturized fiberoptic or strain gauge pressure transducer is inserted into the brain substance. The miniaturized transducer greatly reduces the invasiveness of the insertion procedure, but no practical method exists to establish a baseline measurement. This creates accuracy problems since many factors over the course of treatment may shift baseline measurements. Additionally, the ICP sensor and data from it alone do not allow a direct measurement of how edematous or congested the specific region of the brain is. Furthermore, swelling provides a widely ranging pressure change related to age and causes of the swelling. Finally, the ICP sensor alone does not provide a measurement of real time brain stiffness or compliance, a helpful indicator of imminent deterioration risk. Static measurement may be achieved by magnetic resonance imaging (“MRI”), but this does not provide real time data. Real time information would greatly facilitate the detection of true shunt failure in the management of hydrocephalus. However, since real time measurement cannot be done with internal sensors, shunt failure must be inferred from late presenting clinical deterioration and anatomical changes as seen in imaging studies of the MRI. Additionally, the transport of a critically ill patient to an MRI facility is hazardous. There is therefore a need for an instrument which may be inserted through a single aperture in the skull for simultaneous and continuous monitoring of both intracranial pressure and cerebral water content. There is another need for an instrument which may continuously measure pulsatile changes, altering apparent water content relating to beat-to-beat tissue perfusion due to cardiac output of blood to the brain. There is a further need for an instrument which provides the continuous measurement of tissue congestion related to venous back pressure from mechanical ventilation. There is another need for an instrument which derives the percent water content of the brain for comparison against normal values. There is yet another need for a system to monitor the more gradual baseline changes in wetness or brain edema of intracellular or extracellular origin related to the disease process. There is another need for an instrument which can simultaneously display the intracranial pressure (ICP) waveform and the pulsatile perfusional or momentary congestion changes of the brain. There is still another need for an apparatus and method for comparing the differences in lagtime between the ICP and perfusional waveforms, from which a realtime measurement of brain stiffness or compliance is derived. SUMMARY OF THE INVENTION These needs may be addressed by the present invention which is embodied in one aspect of the invention which is a probe for measuring tissue water content in a region of interest in the brain. The probe has an implantable tissue water content sensor having two plates with a proximal and distal end. The two plates are separated by a dielectric material and the distal end is implantable in brain tissue. An impedance matching circuit is coupled to the proximal end of one of the plates. A first output terminal is coupled to the matching circuit resistor and a second output terminal is coupled to one of the plates. A remotely positioned frequency spectrum analyzer receives an output signal from the first and second output terminals. A digital computer has a display, the digital computer having an input coupled to the output signal from the water content probe and the spectrum analyzer, the computer programmed to display the resonant frequency of the sensor indicative of water content in the brain tissue. Another aspect of the present invention is a method of measuring tissue water content in a selected region of interest in the brain. A capacitive sensor having two plates outside the selected region of interest is calibrated and the resonant frequency of the sensor in air is determined. The capacitive sensor is calibrated in a mixture of water and NaCl. The resonant frequency of the sensor in the mixture is determined. A linear baseline frequency in relation to water content based on the resonant frequencies of the sensor in air and the mixture is established. The capacitive probe is implanted through a skull aperture such that the capacitive plates are exposed to the brain cortex and subjacent white matter. Interrogatory frequency scanning by a spectrum analyzer coupled to the sensor is produced to determine the center point of resonance by passage of the signal. True tissue water content is approximated by curve-fitting the frequency of resonance with the baseline frequency. Another aspect of the present invention is a method of deriving beat-to-beat perfusional and congestion changes in brain tissue. The method includes inserting a water content probe having two conductive plates and a dielectric in the brain tissue. Signals at different frequencies on the water content probe are sent. A standing wave ratio at different frequencies is determined. A water content change tracing which fluctuates with cardiac output pulsatile perfusion of the tissue is then determined. Another aspect of the present invention is a method of deriving realtime compliance or stiffness of brain tissue. The intracranial pressure of the brain tissue is measured. An intracranial waveform from the measurements of the intracranial pressure is then plotted. The pulsatile congestion changes in water content of the brain tissue is measured. A pulsatile congestion change waveform is plotted from the measurements of the pulsatile congestion change. The waveforms of intracranial pressure and the pulsatile congestion change in water content on a computer are simultaneously plotted. The stiffness of the brain is then determined from the simultaneous plotting. Another aspect of the present invention is a probe for measuring tissue water content in a region of interest in the brain. The probe has an implantable tissue water content sensor having two plates with a proximal and distal end. The two plates are separated by a dielectric material and the distal end is implantable in brain tissue. A signal transmitting circuit is coupled to the proximal end of one of the plates. A signal receiver is provided. A remotely positioned frequency spectrum analyzer is coupled to the signal receiver. A digital computer is provided having a display and an input which is coupled to the output signal from the water content probe and the spectrum analyzer. The computer is programmed to display the resonant frequency of the sensor indicative of water content in the brain tissue. It is to be understood that both the foregoing general description and the following detailed description are not limiting but are intended to provide further explanation of the invention claimed. The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the method and system of the invention. Together with the description, the drawings serve to explain the principles of the invention. BRIEF DESCRIPTION OF DRAWINGS This invention is pointed out with particularity in the appended claims. However, other objects and advantages together with the operation of the invention may be better understood by reference to the following illustrations, wherein: FIG. 1 is a perspective view of a brain stiffness probe according to an embodiment of the present invention. FIG. 2 is a partial cutaway view depicting the probe in FIG. 1 inserted through an aperture in the skull such that it is exposed to direct contact with brain tissue. FIG. 3 is a block diagram with the probe components and remotely placed measuring equipment for both the water content sensor component and intracranial pressure component according to one embodiment of the present invention. FIG. 4 A– FIG. 4D are frequency resonance curves and calibration and measurement of tissue water content taken using a system according to the present invention. FIG. 5 is a waveform diagram showing pulsatile changes in microscopic center frequency shifts in the water content probe according to the present invention due to perfusion of the brain by cardiac pulsatile output. FIG. 6 is a block diagram of a wireless implementation of a water content probe according to the present invention. FIGS. 7A–7B are waveform diagrams which show the phase or lagtime relationship between the pressure waveform and perfusional waveform derived from the water content component of the combined probe according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT While the present invention is capable of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated. In accord with one embodiment of the invention, a combined probe 10 for measuring brain wetness and intracranial pressure is shown in FIG. 1 . The probe 10 has a water content sensor 11 which has two conductive plates 12 and 14 on opposite sides of a printed circuit board (PCB) substrate 16 . The conductive plates 12 and 14 are silver in the preferred embodiment but any suitable conductor material may be used. The substrate 16 in the preferred embodiment measures 5 cm in length, 2 mm in width, and 0.5 mm in depth. The probe 10 has a proximal end 18 and a distal end 20 . Multiple holes 22 extend across the PCB substrate 16 . The holes 22 increase sensitivity to real time pulsatile perfusional changes in tissue as they increase the surface area in contact with the brain tissue. The proximal end 18 has a surface mount resistor 24 on one side. A coaxial cable 26 has a core conductor member 28 and a shielding conductor 30 which is circumferentially located around the core member 28 . The surface mount resistor 24 is coupled between the proximal end 18 and one end of the coaxial cable 26 . The surface mount resistor 24 provides impedance matching between the core 28 of the coaxial cable 26 and the plate 12 . The impedance matching provided by the surface mount resistor 24 and the cable 26 is employed to achieve noise immunity in the cable 26 and allow the analysis electronics to be located at a distance from the water content sensor 11 . Other types of impedance matching circuits such as a balanced antenna approach may be used as well. The plate 14 is connected directly to the shielding conductor 30 of the coaxial cable 26 . The other end of the coaxial cable 26 is connected via an adapter 32 to a controller unit 34 . In this sample, the adapter 32 is a PL250 type which minimizes signal loss to the cable 26 . The water content sensor 11 is inserted through a plastic bolt 36 via an aperture 38 . The plastic bolt 36 has a pair of hex nuts 40 and 42 which are mounted on a main body section 44 . The main body 44 has an exterior surface with threads. A lug nut 46 is coupled to the main body 44 and has corresponding interior threads. The lug nut 46 may be rotated on the main body 44 and provides a connection for the cable 26 . The probe 10 is inserted to a depth in brain tissue up to the plastic bolt 36 via the aperture. The hex nuts 40 and 42 and the lug nut 46 are tightened on the main body 44 of the bolt 36 to provide a seal and to allow the plastic bolt 36 to be positioned and held in the aperture 38 . The bolt 36 is designed such that the surface mount resistor 24 lies about 1 mm above the surface of the brain, placing nearly the full length of the plates 12 and 14 in the brain tissue. Since the water of the brain bears a moderate salinity (typically 130–150 mEq Na+ per 1000 ml), an extremely thin-sputtered layer of insulation 50 insulates the electrical plates 12 and 14 from direct tissue contact. The insulation layer 50 is Teflon in the preferred embodiment, but any type of insulation may be used. The insulation layer 50 allows the point of resonance of the water content sensor 11 to be precisely measurable. The configuration of the capacitive plates 12 and 14 may be used in a tubular configuration to allow a silicone external ventricular drain through the lumen. In such a configuration, the electrically conductive plate surfaces are located on the length of the tube on opposite hemispheres to create a similar capacitive effect. FIG. 2 shows a cutaway view of a head 60 with a brain 62 shown through the frontal lobes as seen by a typical MRI. The brain 62 is encased by a cranium 64 . The containment of the cranium 64 creates pressure on the brain 62 which may be excessive due to fluid buildup. A skull aperture 66 (or burr hole) is created in the cranium 64 after a scalp incision. This routine procedure in the intensive care unit would normally be followed by the introduction of an ICP sensor or ventriculostomy catheter as is presently known. The plastic ventriculostomy bolt 36 in the preferred embodiment is commercially available through Codman and Shurtleff Incorporated, Raynham, Mass. The plastic bolt 36 is tapped and threaded snugly into the cranium 64 . The water content sensor 11 is passed through the bolt 36 to a depth such that the sensing capacitive plates 12 and 14 are exposed to cortex and white matter of the brain 62 . The plastic bolt 36 provides stable fixation of electrical connections and prevents movement of the sensor 11 in the brain 62 by secure fixation at the skull aperture 66 (burr hole). An intra cranial pressure (“ICP”) sensor 70 passes through the bolt 36 into the subjacent cortical tissue of the brain 62 . The ICP sensor 70 is an electrical strain gauge type and measures changes in resistance due to pressure. Alternatively, any implantable pressure sensor such as a fiber optic sensor may be used. A fiber optic sensor has lasers coupled to dual fiber optic cables. A diaphragm is coupled to the end of the fiber optic cables and distorts light in reaction to pressure, producing changes in either light amplitude or frequency. In other cases, an external strain gauge which is coupled via tubing to a ventriculostomy catheter or a cranial bolt may be used to measure pressure. The output voltage of the ICP sensor 70 is carried by a cable 72 . The strain gauge ICP sensor 70 in this example is commercially available from Codman and Shurtleff Incorporated, Raynham, Mass. but any appropriate pressure sensor may be used. The ICP sensor 70 may be inserted separately from the bolt 36 and/or inserted at a separate site on the cranium if desired. This is to be avoided in most cases, but certain circumstances may require the separate insertion of the ICP sensor 70 and the water content sensor 11 . The respective wiring connections to and from the water content sensor 11 and the ICP sensor 70 are coupled to the controller unit 34 which is at a remote location. Alternatively, the cables may be connected to a signal transmitter if it is desired to eliminate the cables. The technique of positioning the combined sensors is identical to the routine insertion of a ventriculostomy catheter for monitoring and carries with it the same acceptably low risks. FIG. 3 is a block diagram of the control unit 34 of the combined ICP-water content probe 10 . The ICP sensor 70 is a strain-gauge type which has a wheatstone bridge 74 of standard configuration having a pressure transducer 76 and three resistors 78 , 80 and 82 . The voltage of the bridge 74 changes in accordance to pressure changes on the pressure transducer 76 . The output voltage of the bridge 74 represents the sensed pressure on transducer 76 and is coupled to the input of an analog to digital convertor 84 via the cable 72 . The output of the analog to digital convertor 84 is coupled to a digital computer 86 . The water content sensor 11 is coupled via the coaxial cable 26 to an input of a spectrum analyzer 88 . The spectrum analyzer 88 in the preferred embodiment is an AEA-Tempo 150-525 Analyst manufactured by Tempo Research of Vista, Calif. The spectrum analyzer 88 sweeps an interrogating frequency from 150 MHZ to 550 MHZ every 2 seconds to the water content sensor 11 in the preferred embodiment. The frequency spectrum for measuring brain water content without interference from other sources is optimally measured between 400 and 600 MHZ. However, other ranges may be useful depending on the probe length. The direct output from the spectrum analyzer 88 is coupled to the digital computer 86 and a second output is coupled to an analog to digital convertor 90 . This allows display of the resonant frequency of the water content sensor 11 determined from the direct output, as well as heart beat to heart beat changes in frequency and standing wave ratio (SWR) from the digital to analog converter 90 . The outputs from the spectrum analyzer 88 and the digital to analog convertor 90 are plotted on a display 92 . The display 92 is preferably a high resolution monitor but any display device may be used. The digital computer 86 contains software necessary to simultaneously display the pulsatile waveform outputs from the ICP sensor 70 and the water content probe 11 on the display 92 . As will be explained below, the brain water content and blood congestion alter the resonant frequency of the water content probe 11 and provides an indication of the real time read out of apparent tissue water content and the stiffness of the brain 62 which is independent of baseline water content or pressure. FIGS. 4A–4D illustrates the process of probe calibration and water content determination of brain tissue which is displayed using the software on the digital computer 86 in conjunction with the display 92 . The water content sensed by the water content sensor 11 of the probe 10 in FIGS. 1 and 2 is indicative of the effect of the surrounding tissue dielectric on the speed of transmission of the interrogating signal through the plates 12 and 14 . Similar in concept to time domain reflectometry and familiar to those skilled in the art, the spectrum analyzer 88 will display a resonant frequency when the water content sensor 11 is placed in tissue. This resonance is a function of plate capacitance of the plates 12 and 14 (most strongly affected by probe length in this configuration) and the adjacent dielectric of the material of the substrate 16 . The PCB dielectric material 16 between the plates 12 and 14 and the extremely thin-sputtered layer 50 have dielectric constants near air (dielectric of 1). In contrast, the brain is normally about 70% water. As the dielectric of H2O is 80, the tissue water content overwhelmingly determines the resonant frequency measured from the water content sensor 11 . FIG. 4A shows the output plot of the spectrum analyzer 88 displayed by the digital computer 86 when the water content sensor 11 is entirely exposed to air. Since no significant water content related dielectric slows the signal in air, the resonant frequency of the water content sensor 11 is 440 MHZ. FIG. 4B shows the output plot when the water content sensor 11 is inserted in a 100% normal saline and water compound (simulating brain water and salinity). The resonant frequency of the water content sensor 11 has decreased to 167 MHZ as shown in FIG. 4B . This reduction is due to the overwhelming dielectric effect of the surrounding water with its high dielectric constant. FIG. 4C shows the sharp resonant curve of the output of the water content sensor 11 when placed in the brain tissue 62 as shown in FIG. 2 . The resonant frequency is 307 MHZ in FIG. 4C . The water content of the brain tissue 62 is proportional to the resonant frequency. The different resonant frequencies sensed by the sensor 11 in differing conditions of water content may be plotted. FIG. 4D shows the linearity of a typical output curve from the water content sensor 11 from submersing the sensor 11 in water as in FIG. 4A to full exposure in air as in FIG. 4B . By testing the water content sensor 11 in tissue utilizing dry and wet weight water content determinations, the linear range of clinical significance from 65% (very dehydrated brain) to 80% (very edematous brain) may be tested and provides a measurement standard for water content determination. The measurable accuracy of the water content sensor 11 is up to 0.1% of water content change. In clinical use, however, the absolute local water content determination is not as useful as the trending of water content of the brain tissue over the course in the intensive care unit against a baseline measurement. The long term trends are more useful data since insertion of the water content sensor 11 , as any probe, into the brain 62 , causes a temporary injury edema which develops about the sensor 11 and artificially increases the baseline water content in the region. Additionally, effects of local minor accumulation of a non-flowing blood clot against the sensor plates 12 and 14 or incomplete passage to full depth of the plates 12 and 14 will offset the true water content baseline. Despite these considerations, the baseline measurement is used as a control against the course of illness and therapeutic intervention with dehydrating drugs such as furosemide and mannitol or ventilator changes provide a real time feedback of impact of the physician's regimen on the patient. When the baseline water content is plotted over hours of time on a computer such as the computer 86 , gradual shifts in the water content may be analyzed. For example, the initial shift in water content represents the initial placement edema and its resolution. The longer term shift in water content may represent the trend of brain swelling in the region of monitoring, edema due to head injury, or the effects of therapy. Alternatively, the changes in resonant frequency may also be logged using a spectrum/frequency 2 analyzer such as a Model HP8568A manufactured by Hewlett-Packard. However, much smaller changes of significance to the course of the illness may be measured from heart 4 beat to heart beat as will be explained below. Thus, the water content sensor 11 may be used in isolation without the associated intracranial pressure sensor 70 , yielding profitable 6 data for the patient. FIG. 5 shows a pulsatile baseline 500 obtained from minute apparent water 8 content change. Either one of two techniques may be used to obtain the water content change on a heart beat to heart beat basis. The first technique involves use of the frequencies around the resonant frequency. When the spectrum analyzer 88 is employed to identify the standing wave ratio (“SWR”) at resonance, a properly placed water content sensor 11 will show an SWR of 1.0. The frequency of resonance relates to the water content which is 307 MHZ in FIG. 4D . However, if the frequency just to the right of the resonant point in FIG. 4D is selected where maximum change in SWR occurs per unit frequency change, typically an SWR of about 1.15, the beat-to-beat change of SWR may be plotted. The beat to beat SWR changes thus correlates to the local increased water content sensed by the water 18 content sensor 11 which is due to transient increased tissue congestion and arteriolar dilation due to blood flow. An undulating waveform 502 as a function of time is shown in FIG. 5 . The undulating waveform 502 is measured from the water content sensor 11 as a function of the change in SWR from heart beat to heart beat. A slower baseline undulation relates to back pressure on the venous side of the brain from positive pressure ventilation of the patient or may be evoked by transient jugular vein compression (termed the Queckenstedt maneuver). Alternatively, the beat-to-beat effect may be measured by tracking the center frequency of resonance deviation when the water content sensor 11 in FIGS. 1 and 2 is viewed as the variable component of a simple LC resonant circuit 100 as shown in FIG. 6 . The sensor 11 is coupled to an inductor 102 . The sensor 11 and the inductor 102 may thus be integrated in an implanted sensor unit 104 . A second inductor 106 is coupled to the processing circuitry which includes a signal generator and resonant frequency measurement device as explained above. Since the value of the first inductor 102 is fixed, the resonant frequency will shift as a function of water content of the tissue surrounding the sensor unit 104 . The resonant frequency is measured wirelessly by sensing magnetic field energy from the second inductor 106 and the signal generator. A significant advantage of this approach is that beat-to-beat pulsatile changes and baseline water content may be measured wirelessly using a spectrum analyzer pick-up circuit across the scalp from a wholly implanted resonant circuit. This technique allows long term, wireless monitoring of a region of interest over months to years for determining optimal compliance and control of hydrocephalus in patients treated by a ventriculoperitoneal shunting procedure. With reference to FIGS. 1 and 2 , when the intracranial pressure (ICP) waveform is plotted simultaneously with the pulsatile water content waveform derived from the two techniques described above, a phase relationship between the waveforms is seen. FIG. 7A shows a simultaneous plot of pressure 600 versus a pulsatile water content plot 602 . The pressure plot 600 precedes pulsatile congestion as sensed by the water content probe plot 602 . This indicates that peak vascular congestion lags peak pressure. FIG. 7A depicts the phase relationship plotted of a healthy, normal brain. In FIG. 7A , brain stiffness is within acceptable levels and thus the phase of beat to beat water content resonant frequency is phase shifted from the pressure changes by 115 degrees. In contrast, FIG. 7B shows the pressure and water content plots 600 and 602 superimposed on each other in an example of worsening brain compliance or stiffness. The beat to beat water content resonant frequency is phase shifted from the pressure changes by 68 degrees. This relationship is also demonstrated by a combined ICP-blood flow probe such as when monitoring a patient with a thermal probe as described in U.S. Pat. No. 4,739,771 to the same inventors and incorporated by reference herein. In a normal, relaxed brain, the peak flow or vascular congestion may lag substantially, especially in a child with an open antereor fontanel. As the brain becomes progressively swollen with brain edema in head injury the lag narrows until the two waveforms are essentially co-incidental. Similarly, poor compliance in a patient with shunt failure will show the pattern of narrowing of lag time. The relationship can also be measured in real time as a function of phase lag adjusted for frequency (heart beat), akin to phase lag plotting in current phase compared to voltage phase in inductive circuits. Thus, the relationship by lag in seconds or phase angle adjusted for frequency provides a measure of brain stiffness which is independent of transducer amplitude, accuracy or stability, allowing a frequency domain relationship applicable to long term monitoring including implants. It will be apparent to those skilled in the art that the disclosed measurement method and apparatus described above may be modified in numerous ways and assume many embodiments other than the preferred forms specifically set out and described above. Alternatives to the capacitive water content sensing technology include time domain reflectometry and square-wave frequency based sensors as well as fiberoptic sensors. The time domain reflectometry views the sensing components as a model transmission line. The reflection of a signal is measured as a function of water content. The square wave frequency based sensor uses a broad range of frequencies to determine water content as a function of the frequencies observed. The proper interpretation of the square wave frequency signals requires the appropriate circuitry. The fiberoptic sensor uses a light signal of a certain wavelength which is propagated down an implanted fiber. An optical grating is used to determine reflection of the light signal which is a function of the water content. The pulsatile flow relationship to the ICP waveform can be derived by use of transducers such as thermistors (as described in the author's cited patent), or other heat clearance transducers as well as by transcranial impedance measurement and local tissue laser Doppler technique. The transcranial impedance measurement is performed by placing an ohmmeter on the head and measuring the signals at high frequency. An alternate impedance measurement may be used using a four probe method. Two impedance probes measure the output while two probes input the signal. The laser Doppler technique uses a laser to send a signal to the tissue of interest. The shift in Doppler frequency is measured to determine the water content. An antenna sensor may be used for the water content sensor instead of the capacitive approach explained above. The entirety of the circuitry which includes the implanted circuit with an antenna to sense the water content in the tissue and a transmitter can be reduced to an integrated circuit as part of an implant or integrated onto the probe itself, allowing transcranial, wireless interrogation. The present invention is not limited by the foregoing descriptions but is intended to cover all modifications and variations that come within the scope of the spirit of the invention and the claims that follow.

A method and system to determine brain stiffness is disclosed. A probe to measure tissue water content is inserted through an aperture (burr hole) in the cranium into brain tissue. The probe has two electrically separated plate conductors with a dielectric which forms a capacitor plane. One conductor has a surface mount resistor to allow exact impedance matching to the core of a coaxial cable. The other conductor attaches electrically to the shield of the coaxial cable. The probe is stabilized in the brain tissue through a plastic ventriculostomy bolt which has been secured by screw tapping into the cranium. The coaxial cable connects to a spectrum analyzer. Brain water content and blood congestion alter the resonant frequency of the probe, allowing a realtime readout of apparent tissue water content. By monitoring the momentary shift in center resonant frequency or, alternatively, the standing wave ratio slightly off resonant frequency, a beat-to-beat pulsatile waveform is derived relating to the perfusion of the brain. A strain gauge intracranial pressure sensor (ICP) is separately affixed through the bolt and adjacent to the water content probe. By comparing the phase angle or lag time difference between the pressure tracing and the perfusion tracing, a realtime measurement of organ stiffness or compliance is derived.

This is a continuation of application Ser. No. 08/731,149 filed Oct. 10, 1996 now U.S. Pat. No. 5,923,827, which is a division of application Ser. No. 08/335,343 filed Nov. 3, 1994 now U.S. Pat. No. 5,598,548. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory management device which operates to divide a memory into storage blocks so that the stored content is allowed to be erased only in blocks and a facsimile apparatus which is arranged to use the memory management device. 2. Description of the Related Art Dynamic RAMs (DRAM) and static RAMs (SRAM) are representatively used as memories. The DRAM needs to periodically rewrite data even if it is powered on, while the SRAM operates to hold data only if it is powered on. Both of these memories fail to hold their data without their powers. These memories are required to have a spare battery for backing then up when the power is interrupted. On the other hand, the ROMs are capable of holding data if the power is off, while the ROM often has difficulty in rewriting data. The EPROMs are capable of rewriting data again and again only if ultraviolet rays are applied thereto. Regrettably, however, the EPROM is required to rewrite all the content stored therein. The EEPROM allows a program stored therein to be electrically erased. The program can be erased also in bits. Further, a kind of ROM called as a flash memory has been currently used. The flash memory has a capability of erasing the stored data in blocks, that is, block by block. As mentioned above, nowadays, many kinds of memories have been commercially made available. Those memories have their merits and demerits. It is now desirous to provide such a memory as keeping the same ease of use as the DRAM or the SRAM and needing no power back-up. The DRAM or the SRAM is capable of easily changing a value of 1 or 0 at the current bit into a value of 0 or 1. On the other hand, the ROM keeps a value of 1 at any bit when it is in the initial state. If some data is written in the ROM, the values of 1 at the bits corresponding to the written data are changed to the values of 0. To return the 0's to the 1's, the ROM is required to do an erasing operation. Hence, unlike the DRAM, the ROM cannot to easily change from the 0's to the 1's. For erasing the stored data, the EPROM enables to only erase all the data. The flash memory enables to erase the data only in blocks. Further, like the DRAM, the EEPROM has a capability of erasing the data in bits, that is, bit by bit. The EEPROM, however, is so expensive that it is not made available for general-purpose goods. SUMMARY OF THE INVENTION The present invention is designed to overcome the above-mentioned shortcomings, and it is an object of the present invention to provide a memory management device which achieves more efficient use of a memory whose data is erased only in each storage block and a facsimile apparatus which is arranged to use the memory management device. In carrying out the object, according to a first aspect of the present invention, a memory management device provides a memory which enables to merely reverse the initial value at each bit and control means which operates to control the memory as considering the bit-by-bit reversed state from the initial state on the memory as a starting state. According to a second aspect of the present invention, a memory management device provides et memory which operates to divide its storage area into clocks and erase the data only in a block-by-block manner, control means which sectionalizes the blocks according to the erasing condition of the information to be stored and store the information in the block having the corresponding erasing condition, and erasing means for erasing the stored content of the block only if the erasing conditions of all the stored informations about each block are met. According to a third aspect of the present invention, a facsimile apparatus for temporarily storing the sending information or the received information in a memory and performing a series of operations containing sending or recording, provides the memory which operates to divide a storage area into blocks and erase the data only in blocks and storing means which operates to store the received information or the sending information in the sectionalized blocks if the information is to be stored in this memory. According to a fourth aspect of the present invention, a facsimile apparatus for temporarily storing sending information and received information in a memory and then performing a series of operations containing sending or recording, provides the memory which operates to divide a storage area into blocks and erase the data only in blocks and control means which operates to read the data from the head of a group of empty blocks concatenated in a predetermined sequence if data is to be stored in one of the blocks of the memory. According to a fifth aspect of the present invention, a facsimile apparatus for temporarily storing sending information or received information in a memory and then performing a series of operations containing sending or recording, provides the memory which operates to divide a storage area into blocks and erase the data only in blocks, storing means which operates to sectionalize the blocks for the sending information and the received information, and erasing means which operates to erase the sending information of one block when all the sending informations of the block are sent out or erase the received information of another block when a series of operations containing recording are done for all the received informations of the block. According to a sixth aspect of the present invention, a facsimile apparatus for temporarily storing sending information or received information in a memory and then performing a series of operations containing sending or recording, provides the memory which operates to divide its storage area into blocks and erase the data only in blocks, erasing means which operates to erase the stored content of the memory in blocks, and control means which operates to couple the block whose content is erased by the erasing means to the tail of a group of empty blocks concatenated in a predetermined sequence. According to a seventh aspect of the present invention, a facsimile apparatus for temporarily storing sending information or received information in a memory and then performing a series of operations containing sending or recording, provides the memory which operates to divide its storage area into blocks and erase the data only in blocks, erasing means which operates to erase the content stored in the memory in a block-by-block manner, and control means which operates to count the empty blocks if a sending or receiving operation is requested while the content of the block is being erased, perform the requested operation if it is equal to or more than the regulated number or keep to erase the data stored in the blocks until the number of actual empty blocks reach the regulated number, and then perform the requested operation. According to an eighth aspect of the present invention, a facsimile apparatus for temporarily storing sending information or received information in a memory and then performing a series of operations containing sending or recording, provides the memory which operates to divide its storage area into blocks and erase the data only in blocks, erasure indicating means for indicating erasure of a block content, display means which operates to change the management data of an indicated block to the content of the block according to the erasing indication and display the erasing information of the block, and erasing means which operates to erase the content of the block whose management data is changed after the erasing information is displayed in the display means. In the first aspect of the present invention, in the case of handling the memory, the memory is just allowed to be reversed from the initial state. Hence, the state reversed from the initial state in a bit-by-bit manner is used as a flag representing the starting state of the memory. This means that the initial state represents the waiting state. In the second aspect of the present invention, the used memory operates to divide the storage area into blocks and erase the data only in blocks. Each block stores only the pieces of information having the same erasing condition. If the erasing conditions of all the pieces of information in the block are met, the informations in the block are erased. The informations having the same erasing condition often have a short period from when it is stored to when the erasing condition is met. On the other hand, if the pieces of information stored in one block have a different erasing condition rather than any other condition, a relatively long period is required until the erasing conditions of all the pieces of information stored in the block are met. By storing the informations having the same erasing condition in the same block, therefore, the content of the block is allowed to be quickly erased. The block is used for storing the new information. This serves to enhance the using effect. In the third aspect of the present invention, in a case that the memory arranged to divide the storage area into blocks and erase the data in blocks is provided to the facsimile apparatus as a memory for storing the sending and receivied informations, if, at first, the sending or the receiving information is stored in one block, only the same type of information stored at first is stored in the block, so that both the received and the sending informations are not allowed to be stored in one block. If one kind of information is stored in one block and the other kind of information is stored in another block, the period taken when all the sending data in one block is sent or the period taken when all the receiving data in the block is recorded is shorter than the period if both kinds of data are stored in one block. In the fourth aspect of the present invention, in a case that the memory arranged to divide the storage area into blocks and erase the data only in blocks is provided to the facsimile apparatus as a memory for storing the sending and the receiving informations, the empty blocks are concatenated in sequence for management so that the blocks are picked from the head one for storing the data therein. This makes it possible to evenly use all the blocks, thereby reducing the probability of failure in each block and hence prolonging the life of the memory. In the fifth aspect of the present invention, in a case that the memory arranged to divide the storage area into blocks and erase the data only in blocks is provided to the facsimile apparatus as a memory for storing the sending and the received informations, either one of the sending information and the receiving information is stored in one block. If all the recorded sending informations are sent from the block where they are recorded, the data in the block is erased. On the other hand, when all the receiving informations are recorded in the block for recording only the receieved information, the overall information in the block is erased. In this state, the probability of establishing the erasing condition about all the informations in each block is higher than the probability given when both of the sending and the received informations are stored in one block. Hence, the period from when the data is stored in one block to when the data is erased from the block is reduced, thereby allowing the using ratio of the blocks to be enhanced. In the sixth aspect of the present invention, in a case that the memory arranged to divide the storage area into blocks and erase the data only in blocks is provided to the facsimile apparatus as a memory for storing the sending and the received informations, if the erasing condition is met and the data is erased in blocks, the block whose content is erased is coupled to the tail of the empty blocks concatenated in the predetermined sequence. The blocks whose contents are erased are coupled in the erasing sequence. Hence, if the empty blocks are used, those blocks are allowed to be evenly used. In the seventh aspect of the present invention, in a case that the memory arranged to divide the storage area into blocks and erase the data only in blocks is provided to the facsimile apparatus as a memory for storing sending and received informations, the erasing means operates to erase the block data if the erasing condition is met in the block. If the sending or receiving operation is requested while the block data is being erased, it is checked whether or not the number of empty blocks is equal to or more than the given number before the operation is executed. This makes it possible to secure storage of the regulated sending or receiving amount. If the number is less than the regulated number, the operation is executed to erase the data of the blocks whose erasing conditions are met until the number of the empty blocks reaches the regulated number. Then, the sending or receiving operation is executed. Moreover, in the seventh aspect of the present invention, in a case that the memory arranged to divide the storage area into blocks and erase the data only in blocks is provided to the facsimile apparatus as a memory for storing the sending and the received informations, the received information may contain the information like a received message of an answering phone which is not permitted to be erased without judgement of a receiver. In this case, the erasure indicating means operates to indicate the erasure. In response to this indication, the display means operates to display the erasure of the block as keeping only the erasing management information of the block in the state that the block is erased. The erasing means operates to erase the content of the block. By this operation, an operator for indicating the erasure can quickly make sure that the erasure is done through the effect of the erasure indicating means. Hence, the operator does not need to wait until the actual erasure is done. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an overall arrangement of a memory management device according to an embodiment of the present invention; FIG. 2 is a view showing an arrangement of a flash memory used in the embodiment; FIG. 3 is a view showing an arrangement of an erase block management area; FIG. 4 is an explanatory view illustrating the use of an erase block in each file; FIG. 5 is a table showing an arrangement of a memory block management area; FIG. 6 is a flowchart showing a checking operation of the flash memory when it is powered; FIG. 7 is a flowchart showing an operation of writing data to the flash memory; FIG. 8 is a flowchart showing an operation of erasing data from the flash memory; and FIG. 9 is a view showing an example of displaying the erasing state of the flash memory. DESCRIPTION OF THE PREFERRED EMBODIMENTS Later, the description will be oriented to a memory management device according to an embodiment of the present invention with reference to the drawings. FIG. 1 is a block diagram showing an arrangement of the memory management device. In FIG. 1, a numeral 1 denotes a network control unit which is connected to a line 2 so that the network control unit 1 controls the connection with a line exchange network, concretely, performs calling, releasing or dialing. A numeral 3 denotes a modem which operates to modulate data to be sent into a signal or demodulate the received data into an original signal. The signal is suitable for data transmission through a phone line. A numeral 4 denotes a reader unit which operates to read a manuscript to be sent or copied. A numeral 5 denotes an operation unit through which an indication given by an operator such as a phone number or settings of an answering phone. A numeral 6 denotes a display unit which operates to display a response or a guide to the operator such as an inputted phone number. A numeral 7 denotes a recording unit which operates to print the received data or the data read by the reader unit 4. A numeral 8 denotes an image processing unit which operates to magnify, reduce, rotate or move the read image or the image to be recorded. A numeral 9 denotes a speech recording and reproduction control unit which operates to control recording of a speech in the answering phone or reproduction of the speech through a speaker. A numeral 11 denotes a flash memory which operates to store the received information, the data to be sent from the memory, or a speech message of the answering phone. A numeral 12 denotes a memory control unit 12 which operates to control the flash memory 11 for storing data to be sent by a facsimile, data received by the facsimile or speech data sent by a phone. A numeral 13 denotes a display control unit which operates to control the reader unit 4, the operation unit 5, the display unit 6 and the recording unit 7. A numeral 14 denotes a main control unit which operates to control the overall arrangement of the device and decode the data received by the facsimile or code the data to be sent thereby. FIG. 2 is a view showing an arrangement of the flash memory 11 used in the facsimile apparatus of this embodiment. As shown in FIG. 2, the flash memory used in this embodiment has a volume of 1 MB. The storage volume is divided into erase blocks, each of which has a volume of 64 KB. The stored data is erased in units of one erase block. Each erase block is composed of one management area for storing management information and 63 memory blocks each for storing data. This management area is composed of an erase block management area for storing information indicating the state of the corresponding erase block and a memory block management area for storing information indicating the state of the corresponding memory block. As the memory block management area, 63 areas are prepared in order to correspond to the 63 memory blocks respectively. FIG. 3 is a view showing the arrangement of the erase block management area shown in FIG. 2. Now, each item provided in the erase block management area will be described later. The management area holds two types of informations, that is, management information and stored information. The management information contains a block erasing state, a block using information, an in-block memory information, a file item, an erase block location, and a next erase block number. The block erasing state indicates whether or not the corresponding erase block is logically erased. The block using information indicates whether or not the erase block is in use. The in-block memory information indicates whether or not a memory block in the erase block is empty, that is, any non-used memory block is left. The file item indicates what kind of information is stored in the erase block. The informations indicated as the file item contain data to be sent (referred to as sending data), received data, a received message and a response message of an answering phone, transmission to be done by a timer (referred to as timer transmission), and a bulletin board to be sent by a facsimile (referred to as facsimile bulletin board). Each erase block stores only one kind of those informations. Another kind of information is stored in another erase block. This is because the data is erased in units of one erase block. If each erase block stores the same kind of information, all the erasing conditions of the stored informations are met for quite a short time. The erasing condition means the termination of transmission of the data for the transmission data or the termination of recording the data for the received data. On the condition, the data is allowed to be erased from the flash memory. The location of the erase block actually indicates the location where the empty erase blocks are ranged in a column for waiting for the data input. With reference to FIG. 4, the using state of the erase block will be described. A file is prepared for each kind of informations to be stored. Each erase block is made to be a leased block for the file when the erase block is used for each file. Each erase block is generated as a leased block for each file. When the total volume of the erase block goes beyond 64 KB, the next new erase block is generated and then is chain-coupled to the full erase block. The empty blocks are chain-coupled so that it is used from the head of the block chain. Further, the data-erased block is given back to the tail of the empty block chain. This makes the erasing time of each erase block uniform. Going back to FIG. 3, the next erase block number indicates the number of a next chained erase block if the erase block is chain-coupled to the empty blocks. The storage information of FIG. 3 is a flag for representing the state of the management information title located in the left side. Except the file item contained in the management information, the initial state is indicated by 1 and the starting state is indicated by 0. For example, in the block erasing state, a non-used state (initial state) is 1, while a used state is 0. For the file item, each kind of information has the corresponding number. The next erase block number indicates FF (hexadecimal representation) given when the erase block is coupled to the tail of the empty blocks. If the next erase block is coupled similarly, the next erase block number indicates the number (00 to FE) of that erase block. As mentioned above, the initial state is 1 and the starting state is 0. This is because the flash memory allows the inversion of 0 to 1 to be executed only by erasure, so that the operation of writing data to the memory allows only the change of 1 to 0. FIG. 5 shows an arrangement of each memory block management area in the erase block management area shown in FIG. 2. Like FIG. 3, the memory block management area holds the management information and the storage information. The management information contains a file erasing state, a file using information, a next erase block location, a next memory block location, a memory in-block data length, a directory state, a directory information, a next page erase block location, and a next page memory block location. The file erasing state indicates whether or not a file stored in the corresponding memory block is erased. This information is meaningless unless it is related to the next file using information and any file is stored. The file using information indicates whether or not the corresponding memory block is in use. As shown in FIG. 4, since the erase blocks being used are coupled for each file, the next erase block location indicates the number of an erase block coupled next to the erase block to which the memory block belongs. If the subject erase block is located at the end of the chain, the number indicates FF. The next memory block location means the number of the next located memory block. The memory in-block data length represents the amount of data in the memory block by the number of bytes. In the directory state, it is declared that the use of the management area is prioritized if the state is determined as "0: in use". Further, the memory blocks for each page are collectively managed. The directory information indicates whether or not the information is stored in the memory block(s) composing the directory. If so the directory information indicates "0" for "closed", while if not, the directory information indicates "1" for "not closed". The next page erase block location represents the location of the first erase block of the next page if the data is sent or received in a page unit. The next page memory block location represents the location of the first memory block of the next page. Like the description about FIG. 3, in the storage information located in the right side of FIG. 5, the initial state is represented by 1, while the starting state is represented by 0. The description will be oriented to the operation of the facsimile apparatus having the flash memory 11 arranged as described above with reference to the flowcharts. FIG. 6 is a flowchart showing the operation of the facsimile apparatus when it is powered on. When the facsimile apparatus is turned on, the operation is executed to determine whether or not data is stored (ST1). If it is determined that no data is stored, it is determined whether or not the flash memory is formatted in a predetermined manner (ST2). If the flash memory is not formatted, it is determined that the flash memory is new. Then, the flash memory is divided into erase blocks, which corresponds to an erase unit (ST3). The generated erase blocks are all empty. Hence, these empty erase blocks are chain-coupled as an empty block group as described with respect to FIG. 4 (ST4). If at the step ST1 it is determined that data is stored, it is determined whether or not any conflicting piece of data exists (ST5). Herein, the operation is executed to search the data whose directory state indicates "not in use" and directory information indicates "not closed". Such a conflicting piece of data may take place when the power interruption causes the operation to be suspended while a file is being created. If the conflicting piece of data is found, the recovery process is executed (ST6). The recovery process varies according to the place where the operation is suspended. If the conflicting data may be saved, the directory of the data is changed from "not closed" to "closed". If it may not be saved, the data of the erase block to which the memory block belongs is erased. According to this operation, all the data is retrieved (ST7) and the conflicting piece of data is recovered. Then, the flow given when the facsimile is powered is terminated. Next, the operating flow of writing data to the flash memory 11 will be described with reference to FIG. 7. Any one of processes is executed such as sending of data from the memory, receipt of data in the memory, receipt of a speech by an answering phone, sending of data by a timer, notice of the bulletin board sent by a facsimile e.g., as in a facsimile-on-demand system (ST101). Then, the operation is executed to check whether or not the erase block is provided for the file corresponding to the executed process (ST102). As described with respect to FIG. 4, this is executed for determining whether or not an erase block group is provided for each file. This is determined from the file item of the erase block management area shown in FIG. 3. If no erase block corresponding to the process is found one erase block is obtained from the head of the empty block group shown in FIG. 4 (ST104). The file item of the given process is described in the management area of the obtained erase block. Then, the block using information is made to be in use and the directory state of the memory block management area is also made to be in use (securing the directory area) (ST105). The data of the corresponding file is written in memory blocks to which the erase block belongs (ST106). In the management area of the memory block in which data is written, the file using information is determined to be in use and the storage information such as a number of bytes of the written data is written in the management area (ST107). If the data is overflown out of one memory block, that is, there remains data left to be written (ST108), the operation is executed to check whether or not the in-block memory information of the management area of the erase block indicates "there exists empty space" (ST110). If yes (ST111), the data is written to the next memory block (ST106) and the storage information described at step ST107 is written in the management area of this memory block. At this time, the number of the memory block in which data writing has just terminated is written in the location of the next memory block to this memory block management area, and the memory blocks are chain-coupled with each other. By iterating the loop composed of the steps ST106 to 108, 110 and 111, the data is written in the memory block. If the erase block is full of data during the writing of data, the operations at the steps ST103, 104 and 105 are executed to obtain an empty block so that the remaining data is written in the obtained memory block. After doing these operations, if no data is left (ST108), the storage informations of the erase block management area and the memory block management area are made to indicate the data-written states. Then, the directory information is made to be set as "closed" (ST109), and the operation is terminated. If no empty block is found at the step ST103, no more data is allowed to be stored. Hence, the operation is terminated. In turn, the description will be oriented to the flow of erasing the data stored in the flash memory at an erase block unit with reference to FIG. 8. At first, it is checked that the operation such as sending of data from the memory, receipt of data in the memory or response of an answering phone is terminated (ST 201). Next, the erase block is examined and it is checked that the block corresponds to the head one (NO. 1) of the blocks NOs. 1 to 16 indicated in the left side of FIG. 2 (ST202). Then, based on the block using information of the erase block management area, it is also checked whether or not the erase block is in use (ST203). If it is not in use, it is checked whether or not the erase block is the last erase block (NO. 16) (ST204). If it is not, a check is done to determine whether or not the erase block corresponds to the next one (ST205). If at the step ST203 the erase block is in use, it is determined whether or not the data in all the memory blocks of the erase block is to be erased (ST210). If the data is to be sent (e.g., fax transmission), the data is erased upon termination of sending of the data , while if the data is to be received (e.g., far reception), the data is erased upon termination of recording of the data. If one erase block contains even one piece of data (one memory block) not to be erased, the operation goes to the step ST204 without erasing the erase block. If all the data contained in the erase block are to be erased, the erase block is allowed to be erased (ST211). Then, the erase block whose data is erased is chain-coupled to the tail of the empty block group as shown in FIG. 4 (ST212). This chain-coupling is logically executed based on the information stored in the erase block management area shown in FIG. 3. It is therefore unnecessary to change the initial storage information upon erasure. That is, in the storage information, the block erasing state is "not", the block using information is "not used", . . . , and the number of the next erase block indicates the tail "FF". After checking the next erase block at the step ST205, it is checked whether or not the request for the operation at the step ST201 is issued (ST206). If it is issued, it is checked whether or not the number of empty erase blocks is equal to or more than the regulated value (ST207). To count the number of the empty erase blocks, the block using information of the overall erase block management area is checked. That is, if the information about each erase block indicates "not used", the number of the "not used" erase blocks is counted. The regulated value is defined by the data about sending and receipt treated by the facsimile apparatus. If the number of the empty blocks is equal to or more than the regulated value, the erasing work is interrupted, the requested operation is executed (ST208). After the operation is terminated (ST209), the serial processes at the steps ST203, ST204 and ST210 to ST212, which was executed by the first erase block, are carried out for the next erase block. These processes are repeated until the subject block reaches the last one (NO. 16) (ST204). By performing such an erasing operation periodically or in response to an indication given by the operation unit 5, it is possible to efficiently use the flash memory 11. Next, the description will be oriented to how an operator erases the content of the memory part. In the case of a message received by the answering phone, the message cannot be erased only after the receiver listens to the message. Further, for the facsimile bulletin board, if no notice period is indicated, an operator other than the person posting the notice cannot understand how long the bulletin board is to be noticed. To cope with this, the facsimile apparatus has to be arranged so that the noticer can give a proper indication of erasing the board through the operation unit 5. In this case, in order for the operator to make sure of the erasure, the erasing state is displayed on the display unit 6. FIG. 9 shows a display example appearing when the data is erased. This example concerns with the case that the operator erases the notice on the facsimile bulletin board. Normally, the display unit 6 displays the date and the time. If an indication of erasing the board is given, to make sure of the indication, the sentence "Is Bulletin Board Erased ?" appears on the display unit 6. Next, "Under Erasing" appears thereon. Then, the original date and time are displayed. This shift of the display is so short that the operator can feel the erasure is immediately terminated. To erase one erase block, however, the facsimile apparatus of this embodiment needs about two seconds. It means that a considerable time is required for erasing the content stored in plural erase blocks. On the display, therefore, the block erasing state of the erase block management area is shifted from "yet" to "done" and the data erasion of the erase block is terminated. After this display, the erasing operation is performed along the flowchart shown in FIG. 8. This makes it possible to realize a more convenient facsimile apparatus. As is obvious from the above description, according to the present invention, if the facsimile apparatus uses such a memory as allowing the data to be erased in blocks, the memory may hold the same operativity as the conventional DRAM or SRAM if the way of use is properly selected. Further, the memory used in the present invention does not need a power supply for holding the stored content. It means that the memory may be easily used. The present invention has the following effects (1) to (8). (1) In the case of using the memory in bits, by setting the initial state as a waiting state and the state reversed from the initial state as a starting state, like the conventional memory, the memory may be used as a flag. (2) Since the memory is managed so that one block stores only the same kind of information, the period when the erasing condition of the block becomes satisfactory is made shorter and thereby the data of the block may be erased quickly. This enables to enhance the efficiency of using the memory. (3) In a case that the facsimile apparatus uses a memory which enables to store data only in blocks, the memory may be arranged so that one block stores only the sending information, while another block stores only the received information. In this arrangement, the period when the erasing condition is made satisfactory in each block is made shorter and thereby the erasure is made faster. This enables to enhance the efficiency of utilizing the blocks in the memory. (4) In a case that the facsimile apparatus uses a memory which enables to store data only in blocks, the empty blocks are logically arranged in a line so that these blocks are picked from the head. As such, the probability of evenly using the blocks is made higher and thereby the failure takes place less frequency. This leads to extending the life of the memory. (5) In a case that the facsimile apparatus uses a memory which enables to store data only in blocks, the sending information and the received information are stored in respective blocks. This serves to shorten the period when the erasing conditions of the informations are met. Immediately when the conditions are met, these informations are erased. This makes it possible to process a lot of data even with a small amount of volume. (6) In a case that the facsimile apparatus uses a memory which enables to store data only in blocks, if the block data is erased after the condition is met, the block is connected to the tail of the empty blocks, so that the empty blocks are coupled in the using sequence. This makes it possible to evenly use the blocks, thereby extending the life of the memory. (7) In a case that the facsimile apparatus uses a memory which enables to store data only in blocks, the block data is erased if the erasing condition of the block is met. When the request for sending or received data is issued while the data is being erased, it is checked that the number of the empty blocks is equal to or more than the predetermined number and then the operation is determined to be done. Hence, during the operation, the memory volume is secured. The data is allowed to be positively sent or received. (8) In a case that the facsimile apparatus uses a memory which enables to store data only in blocks, when an operator erases data in the block, the termination of erasure is displayed at a time when the management data of the block requested to erase the erasing condition is erased. Then, the stored content is erased. By this operation, the operator can immediately make sure that the content is erased and does not have to wait until the actual erasure is done.

A memory management device enables to effectively use a memory which permits its stored data to be erased only in blocks. A facsimile apparatus is arranged to temporarily store sending information and received information in the memory and then to send or receive the information. The facsimile apparatus includes a flash memory whose data is allowed to be erased only in blocks and storage unit for storing the sending or the received information in its own blocks if the sending or the received information is stored in the flash memory.

TECHNICAL FIELD The present invention relates to equipment for servicing oil and gas wells and, in particular, to an apparatus and method for protecting blowout preventers from exposure to high pressures and abrasive or corrosive fluids during well fracturing and stimulation procedures. BACKGROUND OF THE INVENTION Most oil and gas wells eventually require some form of stimulation to enhance hydrocarbon flow and make or keep them economically viable. The servicing of oil and gas wells to stimulate production requires the pumping of fluids under high pressure. The fluids are generally corrosive and abrasive because they are frequently laden with corrosive acids and abrasive proppants such as sharp sand. In some wells, stimulation to improve production can be accomplished at moderate pressure which may be safely contained by blowout preventers (BOPs) and, therefore, stimulation fluids may be pumped directly through a valve attached to the BOPs. This procedure is adopted to minimize expense and to permit full access to the well casing with downhole tools during the well servicing operation. It has been demonstrated that it is advantageous to have full access, or substantially full access, to a well casing during a well stimulation treatment. Full access to the casing permits use of downhole tools which are often required, or at least advantageously used during a stimulation treatment. An apparatus for providing full access to the casing while permitting stimulation treatments at extreme pressures that approach a burst pressure rating of the casing is described in Applicant's U.S. Pat. No. 5,819,851 which issued on Oct. 13, 1998 and is entitled BLOWOUT PREVENTER PROTECTOR FOR USE DURING HIGH PRESSURE OIL/GAS WELL STIMULATION. The patent describes an apparatus for protecting BOPs during well treatments to stimulate production. The apparatus includes a hollow spool that has spaced apart inner and outer side walls that define an annular cavity. A mandrel is forcibly reciprocatable in the cavity. The mandrel includes an annular seal at the bottom end for sealingly engaging a bit guide attached to the top end of the casing. The apparatus is mounted above a BOP attached to a casing spool of the well before well stimulation procedures have begun. The mandrel is stroked down through the BOP to protect it from exposure to fluid pressure as well as to abrasive and corrosive well stimulation fluids, especially extreme pressure and abrasive proppants. The BOP protector provides a simple, easy to operate apparatus for protecting BOPs which provides full access to the well casing with well servicing tools to facilitate well stimulation at pressures approaching the burst pressure rating of the well casing. The BOP protector has been readily accepted by the industry and has been proven to be an effective tool which reduces the cost of well stimulation treatments while enabling an ultimate choice of treatment options. However, further improvements are still desirable because the BOP protector described in U.S. Pat. No. 5,819,851 is a hydraulic unit which is mounted above the BOPs during an entire stimulation process. This raises the high pressure valve which controls the flow of stimulation fluids well above a top of the BOPs, which complicates access and reduces the run-in room for perforating gun strings, and other lengthy tools. Consequently, a low profile BOP protector would be advantageous to lower the position of the high pressure valve for easy access during stimulation processes. In addition, a mechanical lockdown mechanism for securing the BOP protector mandrel in an operative position is considered more reliable because a source of pressurized hydraulic fluid is not required. An apparatus and method of isolating a well tree located on an oil or gas well from the effects of high pressure or corrosion caused by stimulation of a well is described in Applicant's U.S. Pat. No. 4,867,243 which issued on Sep. 19, 1989 and is entitled WELLHEAD ISOLATION TOOL AND SETTING TOOL AND METHOD OF USING SAME. The patent describes an apparatus to permit the injection of fluids, gases, solid particles or mixtures thereof through a well tree while protecting the well tree during well stimulation treatments. The apparatus includes a single hydraulic cylinder supported in an axial alignment over a well tree by at least two elongated support rods. The hydraulic cylinder support rods are connected between a base plate and a hydraulic cylinder support plate for supporting the hydraulic cylinder above the well tree at a distance approximately equal to the height of the production tree. The apparatus permits the insertion of a single length of high pressure tubing through any well tree regardless of its height. Once the high pressure tubing is seated in a well tubing or casing, the hydraulic cylinder, hydraulic cylinder plate and support rods are removed to provide 360° access to a high pressure valve attached to the top of the high pressure tubing. The bottom end of the high pressure tubing has a packoff nipple assembly which is inserted into the production tubing or casing and seals against the inner wall. The extent to which the high pressure tubing extends into the production tubing or casing is unimportant so long as the packoff nipple assembly is sealed against the inner wall. Consequently, variations in the length of the production tree are of no consequence and a lockdown mechanism with a short reach is adequate. Consequently, there exists a need for a mechanical lockdown mechanism that provides a broad range of adjustment to permit packoff with a fixed packoff surface in a wellhead. SUMMARY OF THE INVENTION It is a primary object of the invention to provide a BOP protector which isolates BOPs from well stimulation pressures and fluids while overcoming the shortcomings of the prior art. It is another object of the invention to provide a BOP protector which has a low profile for easy access to a high pressure valve during a stimulation treatment. It is a further object of the invention to provide a BOP protector which is locked down in its operative position by a mechanical lockdown mechanism. It is yet a further object of the invention to provide a BOP protector which has a mandrel that can be separated from a tool used for setting the mandrel. It is still a further object of the invention to provide a BOP protector which is economical to manufacture and maintain. In accordance with one aspect of the invention there is provided an apparatus for protecting a blowout preventer from exposure to fluid pressures, abrasives and corrosive fluids used in a well treatment to stimulate production. The apparatus comprises a mandrel adapted to be inserted down through the blowout preventer to an operative position. The mandrel has a mandrel top end and a mandrel bottom end, the mandrel bottom end including an annular sealing body for sealing engagement with a top of a casing of the well when the mandrel is in the operate position. A mechanical lockdown mechanism detachably secures the mandrel to the blowout preventer, the lockdown mechanism being adapted to ensure that the annular sealing body is securely seated against the top of the casing when the mandrel is in the operative position. The mechanical lockdown mechanism preferably includes a base member that is adapted to be mounted to a top of the blowout preventer, the base member having a central passage to permit the insertion and removal of the mandrel. The passage is surrounded by an integral sleeve having an elongated spiral thread for engaging a lockdown nut that is adapted to secure the mandrel in the operative position. The spiral thread on the integral sleeve and the lockdown nut have a length adequate to ensure safe operation at well stimulation fluid pressures (10,000-15,000 psi). At least one of the spiral thread on the integral sleeve and the lockdown nut has a length adequate to provide a significant range of adjustment, preferably at least about 5″ (12.5 cm), to compensate for variations in a distance between a top of the BOP and a bit guide in the tubing hanger spool where the mandrel packs off. The mandrel may be inserted through the blowout preventer using any type of insertion tool used for the insertion of well tree savers or casing savers. Once inserted, the mandrel is securely locked in its operative position by the mechanical lockdown mechanism. In more specific terms, the invention provides an apparatus for protecting a blowout preventer from exposure to fluid pressures, abrasive and corrosive fluids during a well treatment to stimulate production. The apparatus comprises a mandrel adapted to be inserted down through the blowout preventer, the mandrel having a mandrel top end adapted to protrude above the blowout preventer and a mandrel bottom end that includes an annular sealing body for sealing engagement with a bit guide at a top of a casing of the well when the mandrel is in an operative position. A hydraulic cylinder is conveniently used for inserting the mandrel into and removing the mandrel from the blowout preventer. The hydraulic cylinder is supported by at least two elongated hydraulic cylinder support rods fixed relative to the blowout preventer for supporting the hydraulic cylinder in vertical and axial alignment with the blowout preventer, the support rods and the cylinder being removable when the mandrel is operatively inserted through the blowout preventer and the annular sealing body of the mandrel bottom end is seated against the bit guide. A mechanical lockdown mechanism detachably secures the mandrel to the blowout preventer when the mandrel is in the operative position. A primary advantage of the invention is the low profile which provides easy access to a high pressure valve mounted to the top end of the mandrel to control fluid flow during a well stimulation treatment. A further advantage is the security provided by a mechanical lockdown mechanism, which eliminates concern respecting hydraulic fluid pressure losses in the hydraulic system used to lock down Applicant's prior art BOP protector. Furthermore, the separable insertion tool reduces manufacturing and maintenance costs of the apparatus because a single setting tool can be used to set a plurality of mandrels and a damaged or washed-out mandrel is easily replaced without dismantling the tool. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross-sectional view of a blowout preventer (BOP) protector in accordance with the invention, showing the mandrel in an exploded view; FIG. 2 is a longitudinal cross-sectional view of the BOP protector shown in FIG. 1, illustrating the lockdown nut disengaged from the base plate. FIG. 3 is a front elevational view, partially in cross-section, of the BOP protector in accordance with the invention mounted to a wellhead with the mandrel inserted through the BOP and seated in its operative position; FIG. 4 is an alternate embodiment of the lockdown mechanism used in the BOP protector shown in FIG. 1; FIG. 5 is another alternate embodiment of the lockdown mechanism used in the BOP protector shown in FIG. 1; FIG. 6 is a partial cross-sectional view of a first embodiment of an annular sealing body for sealing against a bit guide mounted to a top of a casing of the well; and FIG. 7 is a partial cross-sectional view of an alternate preferred embodiment of an annular sealing body for sealing against a bit guide mounted to the top of a casing of the well. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a cross-sectional view of the apparatus for protecting the BOPs (hereinafter referred to as a BOP protector) in accordance with the invention, generally indicated by reference numeral 10 . The apparatus includes a lockdown mechanism 12 which includes a base plate 14 , a mandrel head 16 and a lockdown nut 18 which detachably interconnects the base plate 14 and the mandrel head 16 . The base plate 14 is preferably a circular disc that includes an integral sleeve 20 which is perpendicular to the base plate 14 . A spiral thread 22 is provided on an exterior of the integral sleeve 20 . The spiral thread 22 is engageable with a complementary spiral thread 24 on an interior surface of the lockdown nut 18 . The base plate 14 and the integral sleeve 20 provides a passage 26 to permit a mandrel 28 to pass therethrough. The mandrel head 16 is an annular flange, having a central passage 30 defined by an interior wall 32 . A top flange 34 is adapted for connection of equipment, such as a high pressure valve, which will be described below in more detail. A lower flange 36 retains a top flange 38 of the lockdown nut 18 . The lockdown nut 18 secures the mandrel head 16 from movement with respect to the base plate 14 when the lockdown nut 18 engages the spiral thread 22 of the integral sleeve 20 . The mandrel head 16 with its upper and lower flanges 34 , 36 and the lockdown nut 18 with its top flange 38 are illustrated in FIG. 1 as an integral unit assembled, for example, by welding or the like. However, persons skilled in the art will understand that either one of the mandrel head 16 and the lockdown nut 18 be constructed to permit disassembly to enable the mandrel head 16 or the lockdown nut 18 to be independently replaced. The mandrel 28 has a mandrel top end 40 and a mandrel bottom end 42 . Complementary spiral threads 43 are provided on the exterior of the mandrel top end 40 and on a lower end of the interior wall 32 of the mandrel head 16 , so that the mandrel top end 40 may be securely attached to the mandrel head 16 . One or more O-rings (not shown) provide a fluid tight seal between the mandrel head 34 and the mandrel 28 . The passage 26 through the base plate 14 has a recessed region on the lower end for receiving a steel spacer 44 and packing rings 46 preferably constructed of brass, rubber and fabric. The steel spacer 44 and packing rings 46 define a passage of the same diameter as the periphery of the mandrel 28 . The steel spacer 44 and packing rings 46 are removable and may be interchanged to accommodate different sizes of mandrel 28 . The steel spacer 44 and packing rings 46 are retained in the passage 26 by a retainer nut 48 . The combination of the steel spacer 44 , packing rings 46 and the retainer nut 48 provide a fluid seal to prevent passage to atmosphere of well fluids between the exterior of the mandrel 28 and the interior of the BOP when the mandrel 28 is inserted into the BOP, which will be described with reference to FIG. 3 . An internal threaded connector 50 on the mandrel bottom end 42 is adapted for the connection of mandrel extension sections of the same diameter. The extension sections permit the mandrel 28 to be lengthened as required by different wellhead configurations. An optional mandrel extension 52 has a threaded connector 54 at a top end 56 adapted to be threadedly connected to the mandrel bottom end 42 . An extension bottom end 58 includes a threaded connector 60 that is used to connect a mandrel packoff assembly 62 , which will be described below in more detail. High pressure O-ring seals 64 , well known in the art, provide a high pressure fluid seal in the threaded connectors between the mandrel 28 , the optional mandrel extension(s) 52 and the mandrel packoff assembly 62 . The mandrel 28 , the mandrel extension 52 and the mandrel packoff assembly 62 are preferably each made from 4140 steel, a high-strength steel which is commercially available. 4140 steel has a high tensile strength and a Burnell hardness of about 300. Consequently, the assembled mandrel 28 is adequately robust to contain extreme fluid pressures of up to 15,000 psi, which approaches the burst pressure of the well casing. In order to support a packoff gasket 66 , however, the walls of the mandrel packoff assembly 62 are preferably about 1.75 inches (4.45 cm) thick. As will be explained with reference to FIG. 3, it is preferable that the wall thickness of the mandrel packoff assembly 62 be such that it fits closely within the tubing head spool of a well being treated. The mandrel packoff assembly 62 includes a packoff upper end 68 and a packoff lower end 70 . The packoff upper end 68 includes a threaded connector 72 which engages the threaded connector 50 on the lower end of the mandrel 28 or the threaded connector 60 on the extension bottom end 58 of the optional mandrel extension 52 . The packoff lower end 70 includes the annular seal 66 which sealingly engages a top of the well casing as will be described below with reference to FIG. 3 . The annular seal 66 is preferably a thermal plastic or a synthetic rubber seal that is bonded directly to the lower end 70 of the mandrel packoff assembly 62 . The packoff lower end 70 is preferably machined to provide a bearing surface to which the annular seal 66 may be bonded. The annular seal 66 is preferably made from a polyurethane or a nitryl rubber. The annular seal 66 should have a hardness of about 80 to about 100 durometer. The internal diameter of the mandrel packoff assembly 62 is at least as large as the internal diameter of the casing, e.g., 5 inches (12.7 cm). The extension and the packoff assembly are more completely described in U.S. Pat. No. 5,819,851, which is incorporated herein by reference. FIG. 2 illustrates the apparatus 10 , shown in FIG. 1, prior to being mounted above a BOP for a well stimulation treatment. The lockdown nut 18 is disengaged from the integral sleeve 20 of the base plate 14 and the mandrel head 16 is connected to the top end 40 of the mandrel 28 which includes any required extension section(s) 52 and the packoff assembly 62 to provide a total length required for a particular wellhead. The base plate 14 is mounted on the top end of the BOP and the combination of the lockdown nut 18 , the mandrel head 16 and the mandrel 28 , inserted from the top into the BOP using any one of several insertion tools known in the industry. FIG. 3 illustrates an example of the use of the BOP protector 10 , shown in FIG. 1, using a hydraulic setting tool to insert the BOP protector 10 to an operative position for a well treatment to stimulate production. The hydraulic setting tool illustrated in FIG. 3 is described in U.S. Pat. No. 4,867,243, which is incorporated herein by reference. A BOP 74 is connected to a well casing 76 by various casing hangers, well known in the art such as a tubing head spool 78 , for example. The BOP 74 is a piece of wellhead equipment that is also well known in the art and its construction and function do not form a part of this invention. The BOP 74 and the tubing head spool 78 are, therefore, not described. Mounted above the BOP protector 10 , is a high pressure valve 80 which is used for fluid flow control during a well treatment to stimulate production and, also, used to prevent well fluids from escaping to atmosphere from the top of the mandrel 28 during the insertion and removal of the mandrel 28 . The high pressure valve 80 is typically a hydraulic valve well known in the art. The hydraulic setting tool includes a hydraulic cylinder 82 which is mounted to support plate 84 . The support plate 84 includes a passage (not shown) to permit a piston rod 85 of the hydraulic cylinder 82 to pass through the support plate 84 . The support plate 84 also includes at least two attachment points 86 for attachment of respective hydraulic cylinder support rods 88 . The spaced apart attachment points 86 are preferably equally spaced from the central bore to ensure that the hydraulic cylinder 82 and the piston rod 86 align with the BOP 74 to which the hydraulic cylinder 82 is mounted. The hydraulic cylinder support rods 88 are respectively attached on their lower ends to corresponding attachment points 90 on the base plate 14 , which is mounted to the top of the BOP 74 . As is apparent, the base plate 14 and the support plate 84 have a periphery that extends beyond the wellhead to provide enough radial offset of the cylinder support rods 88 to accommodate the high pressure valve 80 . The cylinder support rods 88 are identical in length. The support rods 88 are attached to the respective spaced apart attachment points 86 , 90 on the support plate 84 and the base plate 14 by means of threaded fasteners or pins (not illustrated). The piston rod 85 is attached to the top of the high pressure valve 80 by a connector 92 so that mechanical force can be applied to the BOP protector 10 and the attached high pressure valve 80 to stroke them in and out of the wellhead. When the BOP protector 10 is in the operative position shown in FIG. 3, the bottom end of the packoff assembly 62 is in sealing contact with a bit guide 94 attached to a top of the casing 76 . The bit guide 94 caps the casing 76 to protect the top end of the casing 76 and to provide a seal between the casing 76 and the tubing head spool 78 in a manner well known in the art. As noted above, the extension section(s) 52 is optional and of variable length so that the assembled mandrel 28 , including the packoff assembly 62 , has adequate length to ensure that the top end 40 of the mandrel 28 extends above the top of BOP 74 just enough to enable the mandrel to be secured by the lockdown assembly 12 described above when the packoff assembly 62 is seated against the bit guide 94 . However, the distance from the top of the bit guide 94 to the top of the BOP 74 may vary to some extent in different wellheads. This variation cannot be accommodated by a conventional lockdown mechanism such as taught in Applicant's U.S. Pat. No. 4,867,243. In accordance with the invention, the mechanical lockdown mechanism 12 is configured to provide a broad range of adjustment to compensate for variations in the distance from the top of the BOP 74 to the top end 40 of the mandrel 28 . The complementary spiral threads 22 , 24 (FIG. 1) on the respective integral sleeve 20 and lockdown nut 18 having a length adequate to provide the required compensation. Preferably, the respective threads 22 , 24 are at least about 9″ (22.86 cm) in axial length. A minimum engagement for safely containing the elevated fluid pressures acting on the BOP protector 10 during a well treatment to stimulate production is represented by a section labelled “A” (FIG. 1 ). Sections “B” represent the adjustment available to compensate for variations in the distance from the top of the BOP 74 to the top end 40 of the mandrel 28 . A spiral thread with about 9″ of axial length provides about 5″ of adjustment while ensuring that a minimum engagement of the lockdown nut 18 is maintained. FIGS. 4 and 5 illustrate two alternate embodiments of the mechanical lockdown mechanism 12 in accordance with the invention. In FIG. 4, the spiral thread 24 on the lockdown nut 18 has an axial extent “A” adequate to ensure the minimum engagement required for safety, and the thread 22 on the integral sleeve 20 of the base plate 14 has a full length spiral thread, which includes the “A” section for the minimum engagement and the “B” section for adjustment. The mechanical lockdown mechanism 12 illustrated in FIG. 5 provides a similar adjustable lockdown with length “A” for minimum safe threaded engagement on the integral sleeve 20 and length “B” for adjustment on the lockdown nut 18 . FIGS. 6 and 7 illustrate the packoff assembly 62 in accordance with alternate embodiments of the invention. Field experience has shown that the bit guides of used wellheads tend to become deformed by small chips, dents, or scratches after a period of running in and out with production tubing and downhole tools. In such cases, the annualar seal used in the embodiment of FIG. 1 sometimes permits pressure leakage at high stimulation pressures and the packoff assembly 62 illustrated in FIGS. 6 and 7 may be used for the BOP protector 10 to improve performance, as described in Applicant's co-pending U.S. patent application Ser. No. 09/299,551, filed on Apr. 26, 1999 and entitled HIGH PRESSURE FLUID SEAL FOR SEALING AGAINST A BIT GUIDE IN A WELLHEAD AND METHOD OF USING, which is incorporated herein by reference. In FIG. 6, a high pressure fluid seal 98 is an elastomeric material preferably made from a plastic material such as polyethylene or a rubber compound such as nitryl rubber. The elastomeric material preferably has a hardness of about 80 to about 100 durometer. The high pressure fluid seal 10 is bonded directly to the bottom end of the packoff assembly 62 . The bottom end of the packoff assembly 62 includes at least one downwardly protruding annular ridge 100 which provides an area of increased compression of the high pressure fluid seal 98 in an area preferably adjacent an outer wall 102 of the packoff assembly 62 . The annular ridge 100 not only provides an area of increased compression, it also inhibits extrusion of the high pressure fluid seal 98 from a space between the packoff assembly 62 and the bit guide 94 when the mandrel 28 is exposed to extreme fluid pressures. The annular ridge 100 likewise helps ensure that the high pressure fluid seal 98 securely seats against the bit guide 94 , even if the bit guide 94 is worn due to impact and abrasion resulting from the movement of the production tubing or well tools into or out of the casing 76 . A pair of O-rings 104 are preferably provided as back-up seals to further ensure wellhead components are isolated from pressurized stimulation fluids. The packoff assembly 62 illustrated in FIG. 7 has a thicker wall, and an inner wall 106 which extends downwardly past the bit guide 94 and a top edge of the casing 76 into an annulus of the casing 76 . High pressure fluid seal 108 is particularly useful in wellheads where the bit guide 94 does not closely conform to the top edge of the casing 76 , leaving a gap 110 in at least one area of circumference of a joint between the casing 76 and the bit guide 94 . The gap makes the top edge of the casing 76 susceptible to erosion called “wash-out” if large volumes of abrasives are injected into the well during a well stimulation process. The packoff assembly 62 in accordance with this embodiment of the invention covers any gaps at the top end of the casing 76 to prevent wash-out. The length of the inner wall 106 is a matter of design choice. As noted above, the high pressure fluid seal 108 is bonded directly to the end 112 of the packoff assembly 62 using techniques well known in the art. The high pressure fluid seal 108 covers an outer wall portion 120 of the inner wall 106 . It also covers a portion of an outer wall 122 located above the end 112 . A bottom edge of the outer wall 122 of the packoff assembly 62 protrudes downwardly in an annular ridge 124 as described above to provide extra compression of the high pressure fluid seal 108 to ensure that the high pressure fluid seal 108 is not extruded from a space between the packoff assembly 62 and the bit guide 94 when the high pressure fluid seal 108 is securely seated against the top surface of the bit guide 94 . In use of the BOP protector 10 , the base plate 14 is secured to the top of the BOP 74 with the lockdown nut 18 disengaged from the integral sleeve 20 of the base plate 14 , as shown in FIG. 2 . The combination of the mandrel 28 , mandrel head 16 and the lockdown nut 18 may be supported by a rig or other insertion tool. The high pressure valve 80 is mounted to the upper flange 34 of the mandrel head before inserting the mandrel 28 into the BOP 74 . The high pressure valve 80 is closed to prevent well fluids from escaping from the top end 40 of the mandrel head 28 when the mandrel 28 is inserted into the well. The BOP 74 is fully opened to permit the insertion of the mandrel 28 . The mandrel 28 may be inserted through the BOP 74 using the hydraulic cylinder setting tool illustrated in FIG. 3 . If so, the hydraulic cylinder 82 , support plate 84 and the cylinder support rods 88 are mounted on the top of the wellhead in such a manner that the hydraulic cylinder 82 is supported in vertical and axial alignment with the BOP 74 with the piston rod 86 connected by the connector 92 to the top of the high pressure valve 80 and the cylinder support rods 88 attached at their lower ends to the respective attachment points 90 on the base plate 14 . During insertion of the mandrel 28 , well fluids are prevented from escaping to atmosphere by the packing rings 46 located between the mandrel top end 40 and the interior 32 of the mandrel head 16 , which were described above with reference to FIG. 1 . When the mandrel 28 is inserted to its operative position, the lockdown nut 18 is engaged with the threaded integral sleeve 26 of the base plate 14 . The mandrel 28 is inserted into the BOP 74 until the annular seal 66 sealingly contacts the top of the bit guide 94 and the lockdown nut 18 is rotated down to its locking position so that the mandrel 28 is securely held in the operative position during the entire well treatment to stimulate production. After the mandrel 28 is inserted into the operative position, the insertion tool is removed from the wellhead. The insertion tool is remounted to the wellhead after the well treatment to stimulate production is completed. The insertion tool is then operated to stroke the mandrel 28 upward out of the BOP 74 . The BOP 74 is closed before the bottom end of the mandrel 28 is completely withdrawn from the base plate 14 to prevent well fluids from escaping to atmosphere. After the BOP 74 is closed, the entire assembly of the BOP protector 10 and the high pressure valve 80 as well as the hydraulic setting tool is removed from the top of the BOP 74 . The sequence of the steps described above may be changed to adapt to specific circumstances, as will be apparent to persons skilled in the art. Although a hydraulic setting tool as described above with reference to FIG. 3 has been used to illustrate the use of the preferred embodiment of the invention, other types of setting tool may be used for inserting the mandrel 28 through the BOP 74 to the operative position. For example, a setting tool described by McLeod in U.S. Pat. No. 4,632,183 entitled INSERTION DRIVE SYSTEM FOR TREE SAVERS which issued on Dec. 5, 1984, the entire specification of which is incorporated herein by reference, may be used. Another type of setting tool which may also be used to insert the mandrel 28 is described by Bullen in U.S. Pat. No. 4,241,786 entitled WELL TREE SAVER which issued on May 2, 1979 and is also incorporated herein by reference in its entirety. Each of these patents describe an insertion tool in which the force applied to the top of the mandrel is applied by a pair of horizontally oriented beams which are parallel and spaced apart. The lower beam is attached to the top of the BOP, while the upper beam is attached to the mandrel head. A pair of jacks are operatively coupled between the upper and lower beams at respective ends to lower or raise the upper beam with respect to the lower beam so that a force is applied on the mandrel to insert the mandrel into or withdraw the mandrel from the BOP. Other setting tools or rigs known in the art may also be used to insert or remove the BOP protector in accordance with the invention. Modifications and improvements to the above described embodiments of the invention may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.

A blowout preventer (BOP) protector featuring a low profile and a mechanical lockdown mechanism is described. The BOP protector includes a mandrel having an annular sealing body bonded to its bottom end for sealing engagement with a bit guide which protects a top of a casing of a well to be stimulated with acidifying or fracturing fluids. The mandrel is locked down with a mechanical lockdown mechanism having a broad range of adjustment. The advantages include a low profile, the security of a mechanical lockdown mechanism, and full access to the casing with downhole tools.

BACKGROUND OF THE INVENTION This invention relates to a lining or other material and more particularly to a slip resistant lining material for use within a shoe or other wearing apparel. It has long been recognized that excess motion of the foot with respect to an enveloping shoe contributes significantly to a diminution of athletic ability. Such slipping and sliding of the foot with respect to the shoe can result in loss of balance, over-rolling the mid-sole/out-sole platform, heat build up, blisters, fatigue, stress fractures and the bruising of the toe sometimes referred to as black toe. Relative motion between foot and shoe also produces high stresses on the shoe itself sometimes resulting in shoe failures such as sidewall blow-outs, torn stitching, out-sole and mid-sole separation, component delamination and torn linings. In addition, such relative motion decreases the amount of energy available for the athletic endeavor whether it be walking or climbing or running and jumping. Heretofore, the principal function of shoe lining materials has been to provide a base cushion or protective layer between the wearer's foot or sock and the upper and/or sock lining materials of a shoe. Insole and upper linings have traditionally been made with a leather or woven, knitted or non-woven top lining adhered to a foam backer. The most popular knitted and/or woven linings are smooth or non-gripping which actually enhances the probability of slippage inside the shoe during sporting activities, heavy lifting, rigorous walking or climbing. A need therefore exists for a unique lining material to reduce or eliminate excess motion of the foot within the shoe. It is also been recognized that motion between a hand and an object to be gripped diminishes performance. The material of the present invention may therefore be used to form a grip on, for example, a tennis racket or to form a palm grip on sport gloves. The material may also form a surface of a tape which can serve as a wrap to provide slip resistance. SUMMARY OF THE INVENTION For the purpose of commercialization, the material described herein is known as TacLiner™. The primary purpose and unique benefit of TacLiner™ is to reduce or eliminate excess motion, slippage or wasted motion of the foot within the shoe during athletic and non-athletic activity. In one aspect, the invention is a lining material including a woven, knitted or non-woven material having depending fibers extending outwardly from the material. The material need not necessarily have a nap. The fibers are coated with a gripping agent so that the coated fibers grip a second structure such as a sock or bare foot. Suitable coating materials include rubber-, urethane-, or synthetic- base polymers/monomers which form a fine-beaded or solid coating on the individual fibers or base surfaces of the lining material. It is preferred that the lining material be incorporated within a shoe for gripping a foot or sock of the wearer. The material may also be a tape for wrapping the foot or ankle prior to putting on a shoe. In another aspect, the invention is directed to a method for making such a lining material. The method includes apparatus for coating fibers on the knit, non-woven or woven material with a gripping agent to prevent slippage. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation view, with parts broken away, of a shoe incorporating the lining material of the invention. FIG. 2 is a perspective view of the lining material of the invention. FIG. 3 is a cross-sectional view of coated fibers of the lining material of the invention. FIG. 4 is a schematic illustration of the manufacturing process for making the materials of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENT With reference first to FIG. 1, a shoe 10 is illustrated with a sock 12 contained therein. FIG. 1 is merely exemplary and the gripping lining of the invention is effective with a bare foot. As is conventionally understood, the shoe 10 may include an outsole 14 and a midsole 16. The present invention can be used with any shoes which may be injection molded, vulcanized, flat lasted or welted. The inside may be permanently fixed or removable. In an embodiment of the present invention a sockliner foam 18 has adhered to its top surface a lining material 20 of this invention. The sockliner foam 18 bearing the lining material 20 of the invention is also shown in FIG. 2. With reference now to FIG. 3 which is an enlargement of the circular region 22 in FIG. 2, fibers 24 are coated with a suitable gripping material 26. In particular, the fibers 24 are micro-injected or coated with rubber-, urethane-, or synthetic- base polymer/monomers forming a random fine-beaded or solid coating such as the coating 26 on individual fibers 24 or other base surfaces of the lining material 20. This resulting material is known as TacLiner™. The material is not sticky or tacky to the touch. It is preferred that the lining material 20 be bonded to the sock liner foam 18 with an adhesive 28. The coated fibers 24 gently grip uncoated fibers of a wearer's sock 12 or grip a bare foot to help hold the foot (not shown) in place on the platform of the shoe 10 during both sport and non-sport activity. It is to be noted that the gripping effects of the lining material of the invention are designed to increase as pressure or body weight is applied to the material. A light pressure/body weight will result in virtually no slip resistance, while increased pressure/body weight results in a high degree of slip resistance. The lining material 20 of the invention may be made of knitted, woven and non-woven base materials with or without a nap. Colors of the coatings 26 materials may be clear, colored or multicolored according to design preference. The TacLiner™ material of the invention may be combined with a variety of insole and/or lining foams and utilized in molded and non-molded footwear components. The lining material of the invention is non-abrasive, breathable and highly resilient even after exposure to moisture in the form of perspiration. An exemplary process for manufacturing the lining material of the present invention will now be discussed in conjunction with FIG. 4. A bolt of the lining material 20 is mounted onto a horizontal spindle 30 at the first stage of the coating/finishing system. An open end of the bolt is attached by clips or pins (not shown) and is drawn across tension spools 32. A coating bath 34 includes the coating material 26 to be applied to the fibers 24. An injection roller or drum 36 passes through the coating bath 34 and thereafter contacts the material 20 at the location 38. In a preferred embodiment, the injection roller 36 is an elongated gravure-like drum having uniform bristles or spikes, surface patterns and/or textures so as to cause the fibers 24 to extend from the surface of the material 20 and to coat the fibers 26. After being coated, the material 20 passes through a drying tunnel 40 and is then finished by a bristle brush finishing wheel 42. Thereafter, the material 20 is wound onto a take-up spool 44. For materials requiring heavy coatings of rubber-, urethane-, or synthetic- base polymer/monomer, the coating bath 34 and injection roller 36 stages may be replaced by a pressurized sprayer (not shown) mounted and activated above the material as it is drawn through the coating system. With either method, coatings may be injected through the top side (nape side) and/or backside (knit side) of a given material. It will be appreciated by those skilled in the art that other processes and machines may be used to make the lining material of the invention.

A lining material of a woven, knitted or non-woven substrate. The fibers of the substrate are coated with a gripping agent. The coated fibers grip a second structure to eliminate or diminish relative motion between the second structure and the substrate including the coated fibers.

This is a division of application Ser. No. 17,009, filed Mar. 2, 1979. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to cryostats utilized to produce an inventory of a liquefied cryogen (e.g. helium). The liquefied cryogen can be used to continuously refrigerate and thus operate infra-red detectors, superconducting devices, and the like which require extremely low temperature environments. In the case of helium as the cryogen, temperatures on the order of 4.2° Kelvin (K.) (-268.9° C.) are required to maintain a liquid helium inventory. 2. Description of the Prior Art For small devices cooled to temperatures on the order of that of liquid helium, miniature cryogenic refrigeration systems including a dewar within which is disposed a heat exchanger containing at the cold end thereof a Joule-Thompson valve or orifice have been used. These devices, as shown in U.S. Pat. No. 3,728,868, utilize a source of high pressure gas which is cooled through the heat exchanger and expanded through the Joule-Thompson valve to provide a small inventory of a liquid cryogen (e.g. helium). Other prior art systems for producing liquefied cryogens in volume (e.g. helium) are disclosed in U.S. Pat. Nos. 2,458,894 and 3,360,955. Both of the foregoing patents employ one or more expansion engines, together with multi-stage heat exchangers and Joule-Thompson expansion valves to produce liquid helium. In the case of the '894 Patent, the liquid helium is used in heat exchange with air to liquefy air for subsequent fractional distillation to produce oxygen. The '955 apparatus is used for producing low temperatures to cool various types of electrical apparatus including superconducting computers. One of the problems encountered with all prior art Cryostats is the maintenance of an inventory of liquid helium which has a normal boiling point of 4.2° K. One method of maintaining an inventory of liquid cryogen (e.g. helium) is to provide a continuous supply of gaseous cryogen which is liquefied to replace that which boils off due to heat infiltrating the Cryostat. The venting gaseous cryogen can be collected and recondensed. In order to do this, the vented gas must be recycled to a refrigeration apparatus which, in turn, produces the liquid helium which is reintroduced into the liquid inventory or reservoir. In the case of a superconducting electronic devices (e.g. super conducting magnets, super conducting quantum interference devices and Josephson junction devices) access is required to the liquid inventory so the device being cooled can be placed in the inventory with electrical leads from the liquid inventory to related equipment operating at ambient conditions. Of necessity, this creates an access passage and possible paths of heat infiltration into the Cryostat to promote boil-off of the liquid cryogen with pressure increases inside the Cryostat. It is desirable to have the cryogenic refrigerator disposed in the access passage or within the vacuum space to cool suitable heat stations in the access means to prevent heat infiltration. In order to do this, the refrigerator is preferably disposed within the Cryostat housing. Having the refrigerator in this position, it then becomes necessary to provide means to remove the refrigerator should it have to be serviced, preferably without exposing the liquid cryogen inventory to ambient conditions so as to minimize heat infiltration and cryogen boil-off and to prevent contamination of the cryogen by the ambient atmosphere. A cryogenic refrigerator ideally suited for this application is manufactured and sold by Air Products and Chemicals, Inc., Allentown, Pennsylvania as a DISPLEX® Model CS-308 Closed Cycle Helium Refrigeration System. The displacer-expander refrigerator portion of the Model CS-308 is disclosed in the specification of U.S. Pat. No. 3,620,029, which is incorporated herein by reference. A refrigerator of this type has been used successfully to cool such things as sample holders for Mossbauer Spectroscopy by means of non-contact heat exchange as shown in U.S. Pat. No. 3,894,403. SUMMARY OF THE INVENTION In order to provide a cryostat suitable for receiving and maintaining a supply of liquid cryogen, it has been discovered that a cryogenic refrigerator can be placed in the access way (neck tube) of the Dewar or reservoir of a Cryostat to provide a source of refrigeration. The cryogenic refrigerator is coupled to heat shields disposed in the vacuum jacket of the Cryostat housing and in the neck tube to intercept heat infiltration by cooling the shields to temperatures intermediate that of ambient and the temperature of the liquid cryogen. The refrigerator further includes a final stage with a device to recondense the liquid Cryogen boil-off inside the dewar. Such an apparatus would permit continuous operation of a superconducting device in a bath of liquid cryogen (e.g. helium). Therefore, it is the primary object of this invention to provide a Cryostat utilizing a closed-cycle refrigerator with several stages of refrigeration to intercept heat leak into the liquid cryogen and recondense cryogen boil-off. It is a further object of the invention to provide a Cryostat adapted to removal, repair, and replacement of the refrigerator while the superconducting device continues operation. It is yet another object of the invention to provide a Cryostat with minimized cryogen boil-off during periods when the refrigerator is off and/or being serviced. It is still a further object of the invention to provide a Cryostat wherein constant pressure and temperature of the liquid cryogen is maintained during periods when the refrigerator is off and/or being serviced. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic representation of an apparatus according to the present invention. FIG. 2 is a fragmentary schematic diagram of the apparatus of FIG. 1 illustrating an apparatus for removing the cryogenic refrigerator operating at atmospheric pressure. FIG. 3 is a fragmentary schematic diagram of the apparatus of FIG. 1 with a cryogenic refrigeration removal system adapted for a cryostat with the cryogen at a pressure above or below atmospheric. DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of describing the preferred embodiment, the specification will refer to a liquid helium Cryostat with a removable 4.2° K. (-268.9° C.) refrigerator. The apparatus of the invention is adaptable to any other cryogen that is a gas at normal atmospheric temperature and pressure. Referring to FIG. 1, the Cryostat 10 includes a vacuum housing 12 having an inner shell 14 defining a reservoir for storing a quantity of cryogenic fluid 15 and an outer shell 16. The space 17 between inner shell 14 and outer shell 16 is evacuated. The housing 12 is closed by a cover or warm flange 18 fitted to the vacuum housing 12 by a suitable complimentary flange 20 and sealing devices 22 (e.g. O-rings) to thus effect a vacuum tight seal. Between the inner shell 14 defining the reservoir containing the liquid cryogen inventory 15 and the warm flange 18, the Cryostat 10 includes an access passage or neck tube 24 closed by a vacuum tight closure 26 as is well-known in the art. Neck tube 24 provides a means for placing the device being cooled (e.g. superconducting electronic device 28 inside of the liquid cryogen inventory 15. Projecting from superconducting electronic device 28 are a pair of electrical leads 30,32 for connecting the superconducting electric device 28 to the related electronic equipment (not shown). While it is possible to construct a Cryostat with a single access port or neck tube 24, the preferred structure includes a second access port or neck tube 34 between the warm flange 18 and the inner shell 14 defining the liquid cryogen reservoir. Neck tube 34 is sealed in vacuum tight relationship to the warm flange 18 and includes a suitable closure 36 adapted to receive a cryogenic refrigerator shown generally as 40. Cryogenic refrigerator 40 is of the type adapted to produce refrigeration at three temperatures; namely, 65° K.(-208.1° C.), 15° K. (-258.1° C.), and 4.2° K. (-268.9° C.). A refrigerator ideally suited for this purpose is manufactured and sold by Air Products and Chemicals, Inc. and designated as a DISPLEX Model CS-308 Closed Cycle Helium Refrigeration System. As pointed out above, this refrigeration system is described in U.S. Pat. No. 3,620,029 and includes a first refrigeration stage 42, a second refrigeration stage 43, a multi-stage heat exchanger 44 consisting of heat exchanger 44a, 44b and 44c, a liquid cryogen condenser 46 and a Joule-Thompson valve 48. Refrigerator 40 is adapted to utilize helium as a working fluid which is introduced through a coupling means 50. Included in both the refrigerator and heat exchanger are exhaust line couplings 52,54 to collect returning warm helium for recompression and reintroduction to refrigerator 40. As part of the inlet means 50, a branch conduit 56 is provided so that high pressure helium can be introduced simultaneously to the displacer expander section 58 of refrigerator 40 and the heat exchanger portion 44 of refrigerator 40. First stage 42 of the displacer-expander portion 58 of the refrigerator 40 is thermally connected to heat exchanger 44a. Refrigeration produced at the first stage is used in heat exchanger 44a to precool the incoming high pressure fluid in heat exchanger 44a. Similarly, heat exchanger 44b is thermally connected to second stage 43 of displacer expander portion 58 of refrigerator 40 to further precool the incoming high pressure gas to the temperature of second stage 43 of the displacer-expander 58. Finally, high pressure gas exiting heat exchanger 44b is further cooled in heat exchanger 44c and expanded through a Joule-Thompson valve or orifice 48 to provide a temperature of 4.2° K. (-268.9° C.) in condenser 46. Included within the vacuum space defined by the inner and outer shells 14 and 16 of the vacuum housing 12 are a first radiation shield 60 and a second radiation shield 62. The first radiation shield 60 is thermally connected to the first stage 42 of displacer expander 58 and second radiation shield 62 is thermally connected to the second stage 43 of displacer expander 58. Also included in the neck tubes 24 and 34 are heat stations 64,65 and 66,67 thermally connected to the first and second stages of the displacer-expander 58, respectively. The radiation shields and the heat stations are fabricated from materials having high thermal conductivity such as aluminum or copper, whereas, the neck tubes 24 and 34 are constructed of materials having low thermal conductivity such as stainless steel or fiberglass. In operation, when an inventory of liquefied helium (15) is introduced into the dewar defined by inner wall 14, some of the liquefied gas begins to boil off and helium gas fills the vertical neck tubes and becomes thermally stratified. Thus, there is created a temperature gradient from approximately 4.2° K. in the liquid helium reservoir to ambient temperature at the warm flange 18. Cover plate 26, and refrigerator removal flange 36 seal the neck tubes so that the helium cannot vent to ambient and air cannot leak in. Pressure within the Cryostat 10 and the temperature of the liquid helium 15 is determined by the temperature of the helium condenser 46. For example, the Model CS-308 refrigerator can maintain pressures in the range of about 7 psia (48 KPa) to about 20 psia (138 KPa), which corresponds to liquid helium temperatures of between 3.5° K. (-269.6° C.) and 4.5° K. (-268.6° C.). Heat stations 68,69 attached to the displacer expander refrigerator 58 at the first stage 42 where approximately 65° K. (-208.1° C.) refrigeration is produced and at the second stage 43 where approximately 15° K. (-258.1° C.) refrigeration is produced comprise horizontal plates that terminate in the band which is in close physical proximity to the respective heat station bands on refrigerator neck tube 34. The gap between the bands 68,68a and 69,69a contains helium gas which is in the neck tube 34 and serves to transport heat from one band to the other without the need of mechanical coupling. A band with a diameter of 150 mm, width of 25 mm and gap of 0.1 mm can conduct 10 watts of heat at 65° K. (-208.1° C.) with a temperature drop of 1.5° K. (1.5° C.). Similar band 71,71a and 73,73a are located within the process neck tube 24 where they intercept heat leak in the stratified helium and lead wires 30,32. Heat is conducted from the process neck tube 24 to the refrigerated neck tube 34 through a thermal strap which may be the radiation shields (60,62). The horizontal heat stations (64,66,65,67) in both neck tubes 39,34 respectively serve to establish the temperature in the helium gas. They also help block thermal radiation in the neck tube. Radiation and convective thermal losses in the neck tubes 24,34 may be further reduced by packing the neck tubes with a foam or glass fiber type insulation (not shown). In order to minimize convective heat losses within the refrigerator neck tube 34, it is essential to match the temperature profile in each heat exchanger (44a, 44b, 44c) with the temperature profile in the displacer expander refrigerator 58 and the neck tube 34. Thus, it is preferable to design the heat exchangers such that heat exchanger 44a is positioned between the room temperature flange and the first heat station 64, the second heat exchanger 44b is positioned between the first and second heat stations 64,66, and the Joule-Thompson heat exchanger 44c is positioned between the second heat exchanger 44b and the liquid helium inventory 15. The warm end of each heat exchanger 44a, 44b, 44c is positioned closest to the warm flange 18 of the cryostat 10. When the displacer expander refrigerator 58 is turned off, helium will begin to boil off and will rise through one or both of the neck tubes 24,34, depending upon where a vent valve or valves (not shown) are located. One liquid liter of helium absorbs about 0.73 watt hours (WHr) of heat as it vaporizes at atmospheric pressure and about 1 WHr for every 5° K. (5° C.) rise in temperature. The venting helium cools the heat stations and thus minimizes the boil-off rate. Having the refrigerator 40 mounted in a neck tube 34 results in the refrigerator becoming thermally disconnected when it shuts off in a sense that there is no direct heat path to the liquid helium and the refrigeration in the boil-off helium can be used effectively to intercept heat leak. Pressure and temperature control of the helium is maintained by an auxiliary system such as shown in FIG. 3, as will hereinafter be more fully described, during periods when the refrigerator is off and when it is being replaced. In the case of operation at atmospheric pressure, a simple relief valve is all that is needed. Helium boil-off rate during periods when the refrigerator is off and is being serviced would typically be less than 1 liquid liter per hour for a Model CS-308 refrigerator, thus a surplus helium inventory of 30 liters of liquid would suffice to continue operation for 24 hours and cool down a warm replacement refrigerator. After a new unit is operating, it can be used to liquefy make-up gas over a period of one week (typically) to replenish the liquid that is lost. FIG. 2 shows an apparatus for removing the refrigerator 40 without exposing the liquid cryogen to the atmosphere. In particular, the apparatus of FIG. 2 is ideally suited for units operating at atmospheric pressure. In addition to the refrigerator 40 mounted on flange 36, the underside of flange 36 includes a flexible sleeve 70 which may be of plastic, neoprene rubber, rubberized fabric or the like and may either be tubular or accordion pleated in shape such as shown in FIG. 1. In normal operation the sleeve 70 is folded around the top of the refrigerator flange 36 as shown in FIG. 1. It is preferable to have the sleeve 70 surrounded by a sealed housing filled with helium so that air does not infuse through the material and into the helium space such as shown in FIG. 1 by having a depending flange 37 on the refrigerator flange 36 and suitable sealing means (not shown) as is well-known in the art. In order to remove the refrigerator from neck tube 34, it is simply withdrawn so that it becomes surrounded by flexible sleeve 70 as shown in FIG. 2. As the refrigerator 40 is removed, helium gas is supplied through a purge-vent valve 75 while the refrigerator 40 is being lifted in order to keep the removal sleeve somewhat inflated and out of contact with cold refrigerator 40. Once the refrigerator 40 is lifted, the flexible removal sleeve 70 can be tied at its base by a suitable closure means 72 to form a gas tight seal. If the seal is not perfect a flow of purge gas can be maintained. The refrigerator 40 can then be lifted out of the sleeve 70, breaking the gas seal between the refrigerator removal flange 36 and the refrigerator flange 41. The refrigerator 40 may be removed from the sleeve while it is still cold and taken away for service to any convenient location. The sleeve 70 is then folded with the sealing means 72 in place so that the refrigerator removal flange 36 is again caused to mate with the warm flange 18 of cryostat 10 to maintain a gas tight closure of the cryostat 10. To install a warm refrigerator, the procedure is essentially reversed. First, the refrigerator removal flange 36 is removed from warm flange 18 and the sleeve extended. The refrigerator 40 is put into the extended flexible sleeve and a gas seal is made between the refrigerator flange 41 and the refrigerator removal flange 36. The purge valve 75 on the removal sleeve flange 36 is then used to inflate and deflate the flexible sleeve 70 several times to purge out most of the air and replace it with helium. The sealing means 72 is then released and the refrigerator lowered into the neck tube 34. Lowering refrigerator 40 will result in helium venting through the relief valve 75 due to displacement of helium from the sleeve and venting of cold helium that is warmed by the warm refrigerator. Cold helium flowing up past the refrigerator 40 as it is inserted will cool it down with the coldest gas coming into contact first with the part of the refrigerator that will be coldest when it is operating. Most efficient utilization of the cold helium is obtained if the refrigerator is lowered during a period of 10 to 15 minutes at a rate that results in the helium vent rate being nearly constant. After refrigerator 40 is completely inserted, it is turned on. Referring to FIG. 3, an alternate method of removing the refrigerator from the cryostat 10 includes a rigid removal sleeve 80 mated by suitable flanges 82, 84 in gas tight relationship to a gate valve assembly 86. Also shown in FIG. 3 is an auxiliary pressure control system to maintain liquid helium at a pressure above or below atmospheric while the refrigerator 40 is turned off, being removed, serviced, and reinstalled. The auxiliary pressure control system includes a conduit 90 communicating with neck tube 34 which in turn is connected through a first control valve 92 and subsequently by a suitable conduits to a second control valve 94 and vacuum pump 96. This system also includes a pressure relief valve 98 and flow control valve 100 controlling flow from a helium supply source (not shown). With the apparatus of FIG. 3, the gate valve 86 with valve element 88 normally in the retracted position are an intregal part of the cryostat 10 and affixed to warm flange 18 by suitable sealing means as is well known in the art. Rigid sleeve 80 can be removably attached to flange 84 of the valve assembly 86. Refrigerator removal flange 36 is adapted to be held in sealing engagement with flange 84 of valve assembly 86 and is also adapted to be slidingly, sealingly engaged with rigid sleeve 80. In operation, when the refrigerator is turned off and is to be withdrawn it is removed by withdrawing it upwardly into sleeve 80 as at the same time helium gas is added to rigid sleeve 80 through valve 100 and conduit 90. When the refrigerator 40 is fully withdrawn, the valve element 88 is moved into sealing engagement with neck tube 34 thus acting in the same manner as the seal 72 of the apparatus of FIG. 2. The refrigerator 40 can then be removed from sleeve 80 and serviced as needed. One major difference between the apparatus of FIG. 2 and FIG. 3 is that when the refrigerator is replaced, the sleeve can be evacuated by means of conduit 104 and valve 102 to remove air rather than using a purge technique as disclosed in relation to the apparatus of FIG. 2. While the refrigeration apparatus disclosed in connection with the foregoing description utilizes a modified Solvay cycle other cryogenic refrigerators operating on different cycles such as the Claude Cycle, Sterling Cycle or Gifford-McMahon Cycle may be employed. There may be only one heat station in the Cryostat or there may be more than two at different temperature levels. As set out above, the Cryostat may have a working fluid of hydrogen, neon, or any other cryogen that is normally gaseous at atmospheric temperature and pressure. There may be only one neck tube or there may be more than two with the Cryostat. As set out above, thermal coupling between the refrigerator and the neck tube can be by mechanical means (e.g. conducting straps) or utilize a technique of refrigeration by extended surface such as disclosed in U.S. Pat. No. 3,894,403. It is also possible that after the refrigerator is withdrawn from the flexible sleeve 70 or the rigid sleeve 80, a foam plug can be inserted and the neck tube purged to further reduce liquid cryogen boil-off while the refrigerator is out being serviced. Having thus described my invention what is desired to be secured by letters patent of the United States is set forth in the claims.

A cryostat for maintaining an inventory of a liquefied cryogen including a vacuum jacketed reservoir (Dewar) containing heat shields in the vacuum jacket, the heat shields cooled to different temperatures and a cryogen recondenser cooled by a cryogenic refrigerator. Included in the cryostat is an access passage to place objects in the cryogen and to support the refrigerator, the access passage including means to remove the refrigerator without opening the liquid cryogen to ambient atmosphere.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powered oscillating hand tool, in particular a powered oscillating hand tool comprising a drive unit having an electric motor with a drive shaft to which a sander head can be attached. 2. Description of the Prior Art In conventional sanders of the orbital type, with a shaped shoe, the drive system comprises an eccentric which is restrained so that the sander shoe cannot spin independently of the motor and it therefore describes a regular orbit. The shoes of such sanders are available in a range of shapes and such sanders are in general used for the removal of relatively small quantities of material, for example for detailed work or for finishing. The base of the shoe may be provided with a surface, in particular a hook and loop surface, on which an abrasive sheet may be mounted. European Patent No 610 801 describes a sander which carries a triangular shoe which can be detached from the body of the sander by means of an operating button located at the front corner of the sander. The operating button carries a bolt which is resiliently mounted on the tool and is biased towards engagement under a catch hook provided in the triangular shoe. The sander is further provided, on the edge opposite the operating button, with at least one engagement opening for engaging at least one support claw provided on the triangular shoe. It is a disadvantage of such an arrangement that it is expensive to manufacture and may be difficult to operate to attach and detach the shoe, in particular under the conditions in which the sander is likely to be used. SUMMARY OF THE INVENTION It is an object of the present invention to provide a sander in which the above disadvantages are reduced or substantially obviated. The present invention therefore provides a powered oscillating hand tool comprising (a) a drive unit having an electric motor and a drive shaft; (b) a bearing eccentrically mounted on the drive shaft and located radially eccentrically relative to the drive shaft; (c) a carrier plate mounted on the bearing and (d) a platen for mounting on the carrier plate characterised in that the carrier plate is provided with a first engagement means and the platen is provided with second engagement means to engage with the first engagement means by rotation of the platen relative to the carrier plate. The first and second engagement means preferably together form a bayonet fitting, more preferably a bayonet fitting of the type in which the first engagement means (provided on the carrier) is in the form of one or more apertures and the second engagement means is in the form of one or more hook members. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of a powered oscillating hand tool according to the invention will now be described with reference to the accompanying drawings in which FIG. 1 is a side view, in section of a preferred embodiment of a powered oscillating hand tool according to the invention, with a platen attached; FIG. 2 is a perspective view of the carrier plate of FIG. 1, viewed from above, and FIG. 3 is a perspective view of the platen of FIG. 1, viewed from above. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a sanding device ( 10 ) comprising a drive unit ( 2 ) including an electric motor ( 4 ) located in a housing ( 6 ) and a drive shaft ( 8 ). A fan ( 12 ) mounted on shaft ( 8 ) is arranged to draw air in from mouth ( 14 ) of a carrier plate ( 16 ) permanently mounted to the sanding device ( 10 ) and direct it through extractor duct ( 18 ) to exhaust outlet ( 20 ). Mounted on the drive shaft ( 8 ) is a counterbalance ( 24 ). The counterbalance ( 24 ) is necessary because mounted thereon is a bearing ( 26 ). The bearing ( 26 ) is eccentrically mounted relative to the drive shaft ( 8 ) and hence the need for the counterbalance ( 24 ). It will be readily appreciated by those skilled in the art that the counterbalance ( 24 ) has an excess of weight in the radial direction (relative to the axis of the drive shaft ( 8 )) diametrically opposite to that of the radial direction in which the bearing ( 26 ) projects furthest away from the drive shaft ( 8 ). Any suitable method of mounting the counterbalance ( 24 ) on the drive shaft ( 8 ) may be employed. In this example, a simple press-fit is used. The same method may be employed to mount the bearing ( 26 ) on the counterbalance ( 24 ). In the example shown with reference to FIG. 1, the counterbalance ( 24 ) and the fan ( 12 ) are formed as a single unit around the drive shaft ( 8 ). This is simply for ease of manufacture. They could each be formed as separate units and individually mounted on the drive shaft ( 8 ). The carrier plate ( 16 ) is mounted on the bearing ( 26 ) by any suitable means. In the present example, the carrier ( 16 ) is press-fitted into engagement with the bearing ( 16 ) although it could equally well be secured by moulding or using a nut or the like. Three flexible columns ( 28 ) made of rubber are arranged around the drive shaft ( 8 ). The upper end ( 30 ) of each of the flexible columns ( 28 ) is held in the housing ( 6 ) and the lower end ( 32 ) is located in a recess ( 34 ) provided in the carrier plate ( 16 ). A platen ( 36 ) is detachably mounted on the carrier plate ( 16 ), as will be described in more detail with reference to FIGS. 2 and 3. The carrier ( 16 ) is driven by the electric motor ( 4 ) through drive shaft ( 8 ). Rotation of the drive shaft ( 8 ) will cause the radially internal portion of the bearing ( 26 ) to rotate concomitantly. Because the radially external portion of the bearing ( 26 ) is in rigid contact with the carrier ( 16 ), then this particular portion does not rotate. Because the carrier ( 16 ) is restrained from free rotation by the flexible columns ( 28 ), then the carrier ( 16 ) will exhibit an orbital motion on rotation of the drive shaft ( 8 ). A perforated sandpaper sheet (not shown) may be attached to the outer face ( 38 ) of the platen ( 36 ), for example by the use of hook-and-loop fabric such as that sold as VELCRO® glued to face ( 38 ). Holes ( 40 ) passing through the platen ( 36 ) facilitate the removal of dust etc., from the sanding face through the platen ( 36 ) to exhaust outlet ( 20 ) via the duct ( 18 ). An extractor hose (not shown) may be attached to the exhaust outlet ( 20 ). As can be seen from FIG. 2, the carrier plate ( 16 ) is made from a plastics material, for example glass filled nylon and carries on its underside a plurality of strengthening ribs (not shown). The carrier plate ( 16 ) includes three recesses ( 34 ) which are used to couple the carrier plate ( 16 ) to the sanding device ( 10 ) by means of the flexible columns ( 28 ) which locate in the recesses ( 34 ) in known manner. The centre of the carrier plate ( 16 ) has a boss ( 42 ) which is used to mount the carrier plate on the bearing ( 26 ). The carrier plate ( 16 ) has a plurality of holes ( 44 ) formed therein and spaced at 120° around the central boss ( 42 ). The holes ( 44 ) are formed so that each can accept one of a plurality of projections formed on the platen ( 36 ) which will be described in more detail below. The holes ( 44 ) are shaped so as to provide an area of relatively large cross sectional area which narrows down to a strip of narrow width. Flanking each hole ( 44 ) and extending substantially along the length from the relatively large cross-sectional area to the end of the relatively narrow strip is a further hole ( 46 ). These holes ( 46 ) narrower than holes 44 and are formed so as to allow the piece of plastics material ( 48 ) from which the carrier plate ( 16 ) is formed and which is situated between the holes ( 44 ) and ( 46 ) to act as a spring mechanism. The hole ( 44 ) is shaped so that an inwardly projecting piece ( 50 ) of the plastics material of the carrier plate ( 16 ) is formed at the position shown and acts as a detent. It will also be seen from FIG. 2 that each hole ( 44 ) is associated with a vertically displaced platform ( 52 ) which projects inwardly opposite detent ( 50 ). Flat wall ( 58 ) extends vertically upward along one side of platform ( 52 ). The platen ( 36 ) is provided with a plurality of projections ( 54 ) projecting from the inner face of the platen ( 36 ). In order to mount the platen ( 36 ) on the carrier plate ( 16 ) the platen ( 36 ) is oriented such that projections ( 54 ) are situated directly below each of the holes ( 44 ). The platen ( 36 ) is then urged toward the carrier plate ( 16 ) so that the projections ( 54 ) protrude through their respective holes ( 44 ). As can be seen from the relative orientation of each of the projections ( 54 ) and holes ( 44 ), when the platen ( 36 ) is rotated by approximately 24° then the outer peripheral shapes of the platen ( 36 ) and carrier plate ( 16 ) coincide and also the projections ( 54 ) are rotated about the boss ( 42 ) such that they are held within the holes ( 44 ) by way of the projection ( 50 ) acting as a detent and also the strip of material ( 48 ) of the carrier plate ( 16 ) between the holes ( 44 ) and ( 46 ) acting as a spring urging this detent into engagement with each projection ( 54 ). As can be seen in particular from FIG. 3, each projection ( 54 ) has an overhanging hook ( 60 ) which further includes a portion ( 56 ) formed as a flat face. When the platen ( 36 ) and carrier plate ( 16 ) are rotated so as to be locked together as described above, this portion ( 56 ) lies flat against face ( 58 ) of the carrier plate ( 16 ). This is necessary so that the majority of the oscillating driving force is imparted to platen ( 36 ) by the carrier plate ( 16 ) through these flat and abutting faces ( 56 ), ( 58 ). The platen ( 36 ) is retained from separating and therefore falling off the carrier plate ( 16 ) by way of hook ( 60 ) shown in FIG. 3 co-operating with the platform ( 52 ). As has been described above, the platform ( 52 ) is situated in a plane which is vertically displaced from the plane of the carrier plate ( 16 ) and standing proud thereof. The hook ( 60 ) therefore sits between the platform ( 52 ) and the plane of the carrier plate ( 16 ) and in this way the platform ( 52 ) acts as a vertical catch for the hook ( 60 ). In order to prevent the tip portion of the platen ( 36 ) coming away from the carrier plate ( 16 ) the platen ( 36 ) carries a first ramp surface ( 62 ) as shown in FIG. 3, which ramp surface ( 62 ) co-operates with a second ramp surface ( 64 ) in the carrier plate ( 16 ). It will be understood that the coupling mechanism between the first ramp surface ( 62 ) and second ramp surface ( 64 ) operates to engage the two surfaces, when the platen is rotated to engage the projection ( 54 ) and its hook ( 60 ). As can also be seen from FIGS. 2 and 3 a screw (not shown) aids securing the platen ( 36 ) to the carrier ( 16 ) in addition to the coupling mechanism described above. In particular, the screw serves primarily to prevent the platen ( 36 ) from rotating relative to carrier ( 16 ) during orbital motion. A boss ( 70 ) acts as a guide hole for the passage of the screw (not shown) through the platen ( 36 ). The screw then screws into the threaded blind hole ( 72 ) in the carrier ( 16 ) to secure the platen ( 36 ) to the carrier ( 16 ). One more alternative platen ( 36 ) can be provided, for use in different sanding operations, such as for detail sanding, sanding louvres, where the platen is provided with a finger extension and contour sanding.

A powered oscillating hand tool includes a drive unit having an electric motor and a drive shaft; a bearing eccentrically mounted on the drive shaft and located radially eccentrically relative to the drive shaft; a carrier plate mounted on the bearing and a platen for mounting on the carrier plate. The carrier plate is provided with a first engagement means and the platen is provided with second engagement means to engage with the first engagement means by rotation of the platen relative to the carrier plate. The first and second engagement means together comprise a bayonet fitting.

FIELD OF THE INVENTION [0001] The present invention is in the field of implantable medical devices and prosthesis, particularly, devices useful as both a structural prosthetic for articular tissue and an in vivo scaffold for the regeneration of articular tissue, including tendons for rotator cuff repair, and methods of making and using the devices. BACKGROUND OF THE INVENTION [0002] Proper functioning of the human shoulder is in part governed by the rotator cuff muscles. These muscles originate from scapula (one of the three shoulder bones) and attach to the humerus via fibrous tendons as they approach the outer aspect of the shoulder thereby surrounding the anterior, superior and posterior of the shoulder joint. The motion of the shoulder is facilitated by the contraction of rotator cuff muscles which pull the rotator cuff tendons. Thus the rotator cuff allows movement of the upper arm for activities such as reaching and throwing. [0003] Disorders of the rotator cuff, particularly tears of the rotator cuff tendons, can cause significant shoulder pain and disability. Young athletes, middle-aged workers, and a substantial portion of the elderly population can suffer a rotator cuff injury which prevents them from working, playing sports, enjoying hobbies or performing routine daily activities. Active people, including athletes, are highly susceptible to rotator cuff problems, particularly as they get older. It has been estimated that more than 100,000 rotator cuff surgeries are performed in the United States each year. Rotator cuff lesions are one of the most common causes of upper extremity disability. [0004] A serious concern with a rotator cuff tear is that the rotator cuff has limited healing potential after tears. The non-surgical treatment for rotator cuff tears includes some combination of anti-inflammatory medication, limiting overhead activity, steroid injections, and strengthening exercises often in association with physical therapy. Surgery to repair the rotator cuff is often advised when a rotator-cuff tear causes severe shoulder weakness or when there has been no improvement following non-surgical treatment. Repair of a torn rotator cuff generally consists of reapproximating the tendon edge to a bony trough through the cortical surface of the greater tuberosity. [0005] Traditionally, surgeons use suture and suture anchors to repair weak, frayed and damaged tissue. Several surgical procedures have been performed to cover massive irreparable rotator cuff tears, including tendon transfer, tendon mobilization and tendon autografts patch grafts using biological or synthetic materials [Aoki et al., 1996 J Bone Joint Surg Br. 1996 September; 78(5):761-6; Gerber 1992 Clin Orthop Relat Res. 1992 February; (275):152-60; Kimura et al., 2003 J Bone Joint Surg Br. 2003 March; 85(2):282-7]. Suture anchors were found to be useful in rotator cuff repair because they could be placed with less surgical dissection and allowed for the “mini-open” technique to become popularized. There are two major disadvantages to using bioresorbable suture anchors that are currently available and used in arthroscopic rotator cuff repair. Passing the suture through the rotator cuff can often be challenging due to the limited amount of working area in the subacromial space. While knots can be tied arthroscopically in a secure fashion, the process is very time-consuming and clearly has a long learning curve. Arthroscopic repair has been suggested for rotator cuff repair, however is burdened by a percentage of recurrences that is greater than the repair carried out when an open technique is used [Bungaro et al., 2005 Chir Organi Mov. 2005 April-June; 90(2):113-9]. It has been found that when an open technique is used, good hold can be guaranteed by using reinforced stitches such as the modified Mason-Allen suture. [0006] The clinical results of all current rotator cuff repair techniques are often sub-optimal and often pre-injury functional levels are not obtained. Augmentation devices have not provided a satisfactory alternative. Several factors limit the extensive use of biological grafts including donor site morbidity, limited availability of autografts material the risk of disease transmission from allografts and patch grafts become mechanically weaker over time as they cause adverse reactions. Extracellular matrices are widely employed by sports-medicine and orthopedic surgeons for augmenting the torn rotator cuff and are intended to strengthen the tendon and enhance biological healing. More recently, synthetic bioabsorbable meshes have been commercialized for repair of soft tissues, including the rotator cuff. [0007] Several extracellular matrix products (ECMs) are commercially available and include GraftJacket (Wright Medical Technology), CuffPatch (Organogenesis, licensed to Arthrotek), Restore (Depuy), Zimmer Collagen Repair (Permacol) patch (licensed by Tissue Science Laboratories), TissueMend (TEI Biosciences, licensed to Stryker), OrthoADAPT (Pegasus Biologics), and BioBlanket (Kensey Nash). These products are fabricated from human, cow, or pig skin, equine pericardium, human fascia latta, or porcine small intestine submuccosa. The manufacturers use various methods of decellularization, cross-linking, and sterilization; the end products possess varying properties of strength, stiffness, and suture-failure load. While there are many products available and many thousands of rotator cuff repairs being performed annually with extracellular matrices, little is known about clinical outcomes. One published study by Iannofti et al found that porcine small intestine mucosa (DePuy's Restore patch) did not improve the rate of tendon-healing or the clinical outcome scores of patients with massive and chronic rotator cuff tears. The relatively low resistance to suture pull-out and potential for immunological response (perceived or real) of ECMs has limited widespread use of ECMs for rotator cuff repair. [0008] Depuy Orthopedics Inc, Warsaw, Ind. has developed SIS (intenstinal submucosa) for augmentation of rotator cuff tendon tears. The SIS materials have sold well, but have the disadvantage of originating from a contaminated animal source, necessitating a variety of cleaning steps. Some patients have sustained swelling, and what appears to be a graft versus host reaction to the SIS Material. GraftJacket is a product by Wright medical using cross banked human cadaver skin. While response levels are lower with this product, the material is very poorly degradable. [0009] Some of the recent studies have indicated some advantages of using synthetic augmentation devices to support the healing of torn rotator cuff. Two synthetic, bioabsorbable products were recently 510 k cleared by the FDA, and both indications for use statements include rotator cuff repair. One of these products is SportMesh (marketed by Biomet) which is made from woven Artelon fibers. Artelon is a biodegradable poly(urethaneurea) material. SportMesh is currently under evaluation for treatment of rotator cuff tears at one or more US-based centers. A second synthetic product recently cleared by the FDA is the X-Repair (marketed by Synthasome) which is made from woven bioabsorbable poly(L-lactic acid) (PLLA) fibers. The X-Repair product was evaluated in a canine model and found to improve biomechanical function at 12 weeks. Another product of interest that was cleared by the FDA is Serica's SeriScaffold, a long-term bioabsorbable woven mesh of silk fibers. Two PLLA devices have been evaluated for rotator cuff repair; one study in sheep reported in 2000 showed a 25% increase in strength of the repair and a second study in goats reported in 2006 showed no significant difference in load to failure of the repair. One study by Koh et al. demonstrated the better biomechanical performance of damaged rotator cuff tendon while healing when the tear was augmented with woven polylactic acid structures [Koh et al., 2002 Am J Sports Med. 2002 May-June; 30(3):410-3]. See, for example, U.S. published application 2008/0051888. [0010] There is a need for an alternative strategy to develop an augmentation device for rotator cuff repair and regeneration due to several reasons. First it has recently been found that up to 60 percent of rotator cuff tendon repairs are failing after repair, even in the hands of good surgeons. While some patients do well after surgery even with the re-torn rotator cuff tear, many do not, and in fact a re-torn rotator cuff is a negative predictor of outcome for a patient. Second, is the fact that traditional outcomes of rotator cuff repair are limited by biology. It takes four weeks to heal a rotator cuff repair, during which patients are not allowed to have significant mobilization of the shoulder. However, the decreased mobility of the joint can lead to significant shoulder stiffness which is a serious disadvantage. This clearly shows the importance of an augmentation device that would allow shoulder mobility while healing. Third, often there are gap areas that cannot be closed with rotator cuff tears. An augmentation device when employed could satisfactorily address this concern. [0011] It is an object of the present invention to provide a biocompatible device for augmentation and repair of rotator cuff injuries. [0012] It is still another object of the present invention to provide a method for producing a device for repair or augmentation of rotator cuff injury which results in improved strength retention and ingrowth of new tissue. SUMMARY OF THE INVENTION [0013] A braided rather than woven device has been developed to augment the rotator cuff tendon tissue as it proceeds in healing. The device has two purposes: to provide initial stability to the rotator cuff repair site to allow early mobilization of the upper extremity of the patient, and to allow for reinforcement of rotator cuff tendon repairs to increase the likelihood of successful rotator cuff tendon repairs. The device consists of an inter-connected, open pore structure that enables even and random distribution and in-growth of tendon cells. The braided structure allows for distribution of mechanical forces over a larger area of tissue at the fixation point(s). [0014] The device can be formed of a degradable polymer. The degradable material is designed to degrade after a period of about nine to twelve months, to allow for repair or augmentation of the tendon prior to the device losing the structural and mechanical support provided by the degradable material. [0015] The device is manufactured using 3-D braiding to create the proper porosity for tendon cell ingrowth and in conjunction with the degradable polymer, provides augmentation strength. [0016] The device is implanted at the site of injury preferably during open surgery although it may be possible to implant arthroscopically, by securing the device using interference screws, rivets, or other attachment devices such as sutures. Torn or damaged tendons, or allograft tissue, may be sutured to or placed adjacent to the device to enhance healing or augmentation. BRIEF DESCRIPTION OF THE DRAWING [0017] FIG. 1 is a perspective view of a three dimensional (3-D) braid prepared using standard 3-D braiding techniques with final dimensions of 12 mm wide, 0.8 mm thick, cut to length. DETAILED DESCRIPTION OF THE INVENTION [0018] When developing an augmentation device, a bioresorbable device is highly preferred as it could prevent the need for a second surgery and at the same time significantly prevent long term biocompatibility issues found with permanent metallic, ceramic or polymeric implants. [0019] The resorbable augmentation device needs to closely mimic the biomechanical properties of the tissue to be regenerated for a short span of time during the new tissue formation, until the regenerated tissue could satisfactorily perform the required functions. In addition to these requirements the resorbable augmentation device should present a favorable structure for cell infiltration and matrix deposition for neo-tissue formation. These facts points to the need for the development of a temporary augmentation device that closely mimics the structural features of the native tissue. I. Tendon Rotator Cuff Augmentation Device [0020] A polymeric fibrous structure that exhibits similar mechanical properties of human fibrous soft tissue, such as tendon, and is fabricated using standard 3-D braiding techniques. The mechanical properties of soft tissue and/or the fibrous structures can be determined by the placing a sample in a spring loaded clamp attached to the mechanical testing device and subjecting the sample to constant rate extension (5 mm/min) while measuring load and displacement and recording the resulting strain-stress curve. In particularly useful embodiments, the polymeric braided structure exhibits a stiffness in the range of stiffness exhibited by fibrous soft tissue. Typically, suitable stiffness will be in the range of about 10 to about 500 Newtons per millimeter (N/mm), and suitable tensile strength will be in the range of about 20 to about 1000 Newtons (N). In some embodiments, the stiffness of the polymeric fibrous structure will be in the range of about 20 to about 80 N/mm. The fibrous structure can be prepared using standard techniques for making a 3-D braided structure. The width and length dimensions of the device can vary within those ranges conventionally used for a specific application and delivery device. For example, dimensions of about 10 mm by 10 mm to about 100 mm by 100 mm. The device can be dimensioned to allow it to be rolled or otherwise folded to fit within a cannula having a small diameter to allow arthroscopic or laparoscopic implantation, fitting within openings on the order of about 0.5 mm to about 10 mm. In some embodiments, the fibrous structure defines openings on the order of about 0.5 mm to about 10 mm. In certain embodiments, the fibrous structure is braided using multifilament PLLA fibers that are plied to create a yarn bundle. Each 60 to 100 denier PLLA fiber is made up of 20-40 individual filaments. In particularly useful embodiments, the 3-D braided fibrous structure includes about twenty four 75 denier PLLA fibers made up of 30 individual filaments. The diameter of a 75 denier PLLA fiber is about 80-100 microns while the diameter of an individual filament is about 15-20 microns. In some embodiments, the fibers have a diameter ranging from about 50 microns to about 150 microns. In particularly useful embodiments, the fibers have a diameter ranging from about 80 microns to about 100 microns. In one embodiment, the device is formed using a braiding mechanism with 75 denier degradable polymer such as PLLA, having a relaxed width of between 10 mm and 14 mm and tensioned width of between 8 mm and 12 mm; relaxed thickness of between 0.8 mm and 1.2 mm and a tensioned thickness of between 0.6 mm 1.0 mm. [0021] The braided structure can be packaged and sterilized in accordance with any of the techniques within the purview of those skilled in the art. The package in which the implant or plurality of implants are maintained in sterile condition until use can take a variety of forms known to the art. The packaging material itself can be bacteria and fluid or vapor impermeable, such as film, sheet, or tube, polyethylene, polypropylene, poly(vinylchloride), and poly(ethylene terephthalate), with seams, joints, and seals made by conventional techniques, such as, for example, heat sealing and adhesive bonding. Examples of heat sealing include sealing through use of heated rollers, sealing through use of heated bars, radio frequency sealing, and ultrasonic sealing. Peelable seals based on pressure sensitive adhesives may also be used. [0022] The braided structures described herein can be used to repair, support, and/or reconstruct fibrous soft issue. The braided structures may rapidly restore mechanical functionality to the fibrous soft tissue. The braided structures may be implanted using conventional surgical or laparoscopic/arthroscopic techniques. The braided structure can be affixed to the soft tissue or to bone adjacent to or associated with the soft tissue to be repaired. In particularly useful embodiments, the braided structure is affixed to muscle, bone, ligament, tendon, to or fragments thereof. Affixing the braided structure can be achieved using techniques within the purview of those skilled in the art using, for example, sutures, staples and the like, with or without the use of appropriate anchors, pledgets, etc. [0023] A. Polymeric Materials [0024] Suitable degradable polymers include polyhydroxy acids such as polylactic and polyglycolic acids and copolymers thereof, polyanhydrides, polyorthoesters, polyphosphazenes, polycaprolactones, biodegradable polyurethanes, polyanhydride-co-imides, polypropylene fumarates, polydiaxonane polycaprolactone, and polyhydroxyalkanoates such as poly4-hydroxy butyrate, and/or combinations of these. Natural biodegradable polymers such as proteins and polysaccharides, for example, extracellular matrix components, hyaluronic acids, alginates, collagen, fibrin, polysaccharide, celluloses, silk, or chitosan, may also be used. [0025] Preferred biodegradable polymers are lactic acid polymers such as poly(L-lactic acid) (PLLA), poly(lactic acid) (PLA), and poly(lactic-co-glycolic acid) (PLGA). The co-monomer (lactide-glycolide) ratios of the poly(lactic-co-glycolic acid) are preferably between 100:0 and 50:50. Most preferably, the co-monomer ratios are between 85:15 (PLGA 85:15) and 50:50 (PLGA 50:50). Blends of PLLA with PLGA, preferably PLGA 85:15 and PLGA 50:50 can also be used. The preferred polymer for the non-degradable region is a polyester and the preferred polymer for the degradable region is PLLA. [0026] Material may be applied to the fibers to increase adhesion or biocompatibility, for example, extracellular matrix molecules such as fibronectin and laminin, growth factors such as EGF, FGF, PDGF, BMP, and VEGF, hyaluronic acid, collagens, and glycosaminoglycans. [0027] B. Cell Seeding [0028] The devices can optionally be seeded with cells, preferably mammalian cells, more preferably human cells. Alternatively, they are implanted and cells may attach to and proliferate on and within the devices. Various cell types can be used for seeding. In a preferred embodiment, for ligament and tendon replacement, the cells are either mesenchymal in origin or capable of generating mesenchymal cells. Accordingly, preferred cell types are those of the connective tissue, as well as multipotent or pluripotent adult or embryonic stem cells, preferably pluripotent stem cells. However, the scaffolds can be seeded with any cell type which exhibits attachment and ingrowth and is suitable for the intended purpose of the braided scaffold. Some exemplary cell types which can be seeded into these scaffolds when used for repair, regeneration or augmentation of connective tissue or other tissue types such as parenchymal tissues, include, but are not limited to, osteoblast and osteoblast-like cells, endocrine cells, fibroblasts, endothelial cells, genitourinary cells, lymphatic vessel cells, pancreatic islet cells, hepatocytes, muscle cells, intestinal cells, kidney cells, blood vessel cells, thyroid cells, parathyroid cells, cells of the adrenal-hypothalamic pituitary axis, bile duct cells, ovarian or testicular cells, salivary secretory cells, renal cells, chondrocytes, epithelial cells, nerve cells and progenitor cells such as myoblast or stem cells, particularly pluripotent stem cells. [0029] Cells that could be used can be first harvested, grown and passaged in tissue cultures. The cultured cells are then seeded onto the three dimensional braided scaffold to produce a graft material composed of living cells and a degradable matrix. This graft material can then be surgically implanted into a patient at the site of ligament or tendon injury to promote healing and repair of the damaged ligament or tendon. [0030] Growth factors and other bioactive agents may be added to the graft material. In a preferred embodiment, these include fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and bone morphogenic proteins (BMPs). Adhesive materials such as fibronectin and vimentin can also be added. These are preferably added in amount ranging from 0.1 nanogram to 1 micrograms. Cell isolates (for example, from marrow cells) or biological factors isolated from blood can also be added to the graft or placed with the graft. II. Methods of Manufacture [0031] The device is prepared using standard 3-D braiding techniques and equipment. The device is 3-D braided so that the structure has the desired combination of the fiber properties and porosity resulting from the 3-D braided structure [0032] The geometric parameters which determine the shape and fiber architecture of three-dimensional braids includes braiding angle distribution, fiber volume fraction, number of carriers, and braiding width. The braiding pattern can depend on braiding machinery/technique used. The device peak load strength range is from 20 to 1000 N, with an initial stiffness range of 20 to 500 N/mm. The devices are typically provided in a sterile kit, such as a foil or TYVEX® package. III. Methods of Use [0033] The device is used for repair or augmentation of articular injury, by implanting the device at a site in need of articular repair or augmentation. [0034] In use, the devices are implanted to match the biomechanical properties of the tissue being repaired. This permits an early return to normal function post-operatively. The implanted device bears applied loads and tissue in-growth commences. The mechanical properties of the biodegradable material of the implant slowly decay following implantation, to permit a gradual transfer of load to the ingrown fibrous tissue. In a preferred embodiment, the degradation of the biodegradable material occurs after about 9-12 months. Additional in-growth continues into the space provided by the biodegradable material of the implant as it is absorbed. This process continues until the biodegradable material is completely absorbed and only the newly formed tissue remains. [0035] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed invention belongs. Publications cited herein and the materials for which they are cited are specifically incorporated by reference. [0036] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims

A device has been developed to augment the rotator cuff tendon tissue as it proceeds in healing. The device has two purposes: to provide initial stability to the rotator cuff repair site to allow early mobilization of the upper extremity of the patient, and to allow for reinforcement of rotator cuff tendon repairs to increase the likelihood of successful rotator cuff tendon repairs. The device consists of an inter-connected, open pore structure that enables even and random distribution and in-growth of tendon cells. The braided structure allows for distribution of mechanical forces over a larger area of tissue at the fixation point(s).

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. provisional patent application Ser. No. 61/655,485 filed Jun. 5, 2012, and entitled “Apparatus, Systems, and Methods for Reconfigurable Robotic Manipulator and Coupling,” which is hereby incorporated herein by reference in its entirety. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] At least some portion of the technology disclosed herein was developed while work was performed for NASA on contract number NNJ08JA66C during the period that includes Jan. 29, 2007 to Aug. 29, 2010. BACKGROUND [0003] The disclosure relates generally to automation and robotics, and more particularly, the disclosure relates to manipulator arms, end-effectors, and adapter mechanisms for manipulator arms and end-effectors. Still more particularly, the present disclosure relates to apparatus and methods for interchanging and operating manipulator arms and end-effectors. [0004] The field of automation and robotics augments and extends human activities and exploration both on earth and in space. Stationary robots are common in industrial settings for repetitive tasks such as product assembly and packaging. Mobile robots work in a variety of indoor and outdoor settings, moving through varied terrain and in varied environmental conditions. Mobile robots travel on the ground, through the air, and through water to investigate difficult-to-reach locations, handle chemicals, collect environmental samples and data, patrol property, search for people trapped in rubble, and perform a variety of other tasks. [0005] The physical work of a robot is performed by end-effectors mounted on manipulator arms. Mating adapters connect the end-effector to the manipulator arm and the manipulator arm to the body of the robot. The end-effector may be a hand tool, a power tool, a dexterous gripper, a scientific probe, a scoop, or any other attachable device that allows the robot to engage its surroundings. A manipulator arm connects an end-effector to the body of the robot and provides reach capability. A manipulator arm includes one or more segments or joints each with the ability to move in prescribed directions. Basic movements for joints include pitch, which is like the rotational motion of a human elbow, roll, which is like the motion of a human wrist when the hand is rotated about the forearm axis, and linear extension/retraction. Forming a manipulator arm from multiple joints gives the manipulator more flexibility, i.e., the ability to move in more directions. The objective is to move the end-effector toward a target and to engage the target. Basic movements for an end-effector include translation (up-down, forward-backward, and left-right) and rotation (clockwise and counterclockwise). Each of the three translational movements may be assigned to one axis of a coordinate system defined by three orthogonal, mutually perpendicular axes. The axes may be called x, y, and z. The orientation and starting point (origin) of the group of axes may be defined with reference to one of several places. For example, the orientation and origin may be established at a fixed spot within the region being explored (earth or moon), on the robot body, or at the connection point of the end-effector. The last two locations would define a moving and rotating coordinate system because the robot moves and turns. [0006] The total number of independent, basic movements that a particular manipulator arm or an end-effector may make is known as its degrees-of-freedom (DOF). Three DOF are achieved by the translational movement along the three axes. Forward and reverse movement along any one axis is considered one DOF. When the end-effector is rotated clockwise or counter-clockwise around any of the three axes, this capability adds three more DOF, for a total of six DOF. Adding more joints to a manipulator arm adds more DOF. [0007] When a manipulator arm is formed from joints with pitch and roll capabilities, performing a straight translational movement of the end-effector requires the simultaneous movement of multiple joints. Moving multiple joints simultaneously is governed by software algorithms stored in a computer or in another control system that may be on the main body of the robot or separate from the robot. [0008] The work required of a particular robot may change, often requiring modifications to the robot. Common modifications or reconfigurations involve replacing the end-effector or the entire manipulator arm. If the new equipment has a different connecting adapter, the adapter on the robot must be either modified or replaced. If the new equipment has the same adapter as the previous manipulator or end-effector, then the exchange will be simpler but may still require significant effort. The end-effector and manipulator arm may be coupled by an adapter using threaded fasters such as bolts and nuts or machine screws, or coupled by clamps, or coupled by a pneumatically-actuated lock mechanism. These coupling methods require one or more tools or a source of compressed air. Furthermore, the exchange of an end-effector and manipulator arm typically requires adjustment to the controlling software to account for the reach, DOF, lift capability, and other parameters of the new equipment. Seemingly simple modifications to a robot can often be time-consuming and labor intensive. [0009] Accordingly, there remains a need in the art for improved devices and methods for reconfiguring robotic manipulators arms and end-effectors. SUMMARY [0010] A robotic manipulator arm is disclosed. The arm includes joints that are attachable and detachable in a tool-free manner via a universal mating adapter. The universal mating adapter includes a built-in electrical interface for an operative electrical connection upon mechanical coupling of the adapter portions. The universal mating adapter includes mechanisms and the ability to store and communicate parameter configurations such that the joints can be rearranged for immediate operation of the arm without further reprogramming, recompiling, or other software intervention. [0011] In some embodiments, a reconfigurable robotic manipulator arm includes a first joint including a first end assembly having a mechanical coupling interface and an electrical interface, and a second end assembly having a mechanical coupling interface and an electrical interface, a second joint including a third end assembly having a mechanical coupling interface and an electrical interface, and a fourth end assembly having a mechanical coupling interface and an electrical interface, wherein the first and fourth end assemblies are connectable at the first and fourth mechanical coupling interfaces to form a first adapter between the first and second joints including an operative electrical connection between the first and fourth electrical interfaces, and wherein the first and second joints are detachable at the first adapter and re-connectable at the second and third mechanical coupling interfaces to form a second adapter between the first and second joints including an operative electrical connection between the second and third electrical interfaces. In some embodiments, at least one of the adapters includes a control board. In some embodiments, the control board is configured to store electrical data, such as operational parameters of at least one of the joints. In some embodiments, the control board is configured to pass power or electrical signals between coupled joints. In some embodiments, the control board is configured to pass power or electrical signals between a joint coupled to a robot or end-effector. [0012] In some embodiments, a joint for a robotic manipulator arm includes a base section, a rotatable section, a motor configured to rotate the rotatable section or the base section with respect to the other section, a brake, and a magnetic brake release switch configured to be activated by a removable external magnet and when activated to release the joint to move freely, wherein a ferrous metal member may augment the performance of the magnetic brake release switch. In some embodiments, the joint includes a position sensor assembly configured to detect the absolute angular position of the rotatable section with respect to the base section wherein the position sensor assembly is mounted on one of the joint sections and passes or moves near a position-indicating design mounted on the other section of the joint. [0013] In some embodiments, an adapter for connecting different portions of a robotic system includes a first assembly including a mechanical coupling interface and an electrical interface, and a second assembly including a mechanical coupling interface and an electrical interface, wherein the first assembly is connectable to a first portion of the robotic system, wherein the second assembly is connectable to a second portion of the robotic system, wherein the mechanical interfaces are connectable in a tool-free manner whereby the electrical interfaces are brought into contact to form an operative electrical connection in the adapter. In some embodiments, the first assembly and the second assembly comprise a plurality of mating pairs of slidably engageable electrical connectors to transfer data and power signals between the first and second assemblies and one or more attached joints. In some embodiments, the transfer of data or power will not occur unless at least one specified pair of mating electrical connectors is engaged, and wherein the other mating pairs of electrical connectors are always engaged whenever the at least one specified pair is partially engaged or engaged. In some embodiments, the first assembly forms a hermetically sealed barrier, or the second assembly forms a hermetically sealed barrier. In some embodiments, the adapter further includes a mechanism for automatically detaching an object from or attaching the object to a robotic joint or manipulator arm, the mechanism including a socket portion including the first assembly, a plug portion including the second assembly, at least one motor-driven surface, wherein the object to be detached or attached may be an end-effector or another joint, wherein the motor-driven surface is configured to induce the rotational engagement of the first and second assemblies, and wherein the mechanism is configured for automatic or manual operation. [0014] Thus, embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The various features and characteristics described above, as well as others, will be readily apparent to those of ordinary skill in the art upon reading the following detailed description, and by referring to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0015] For a detailed description of the disclosed embodiments of the invention, reference will now be made to the accompanying drawings in which: [0016] FIG. 1 is side view of an embodiment of a robotic manipulator arm comprising a series of connected joints in accordance with the principles disclosed herein; [0017] FIG. 2 is a perspective view of a mobile robot base coupled with the manipulator arm of FIG. 1 and an end-effector tool, in accordance with the principles disclosed herein; [0018] FIG. 3 is a perspective view of another end-effector tool that may couple to the manipulator arm of FIG. 1 , in accordance with the principles disclosed herein; [0019] FIG. 4 is a perspective view of an embodiment of a universal mating adapter (UMA), which may also be referred to as a universal mechanical-electrical coupling (UMEC), in accordance with the principles disclosed herein; [0020] FIG. 5 is a sectional view of the UMA shown in FIG. 4 , in accordance with the principles disclosed herein; [0021] FIG. 6 is an exploded view of the UMA shown in FIG. 4 with the components of the plug assembly and the socket assembly identified, in accordance with the principles disclosed herein; [0022] FIG. 7 is a perspective view of the plug connector body of the UMA shown in FIG. 6 , in accordance with the principles disclosed herein; [0023] FIG. 8 is a perspective sectional view of the UMA plug connector body shown in FIG. 7 , in accordance with the principles disclosed herein; [0024] FIG. 9 is a first perspective view of the control board and power board of the UMA plug assembly shown in FIG. 6 , in accordance with the principles disclosed herein; [0025] FIG. 10 is a second perspective view of the control board and power board of FIG. 9 , in accordance with the principles disclosed herein; [0026] FIG. 11 is a first perspective view of a mounting plate of the UMA shown in FIG. 6 , in accordance with the principles disclosed herein; [0027] FIG. 12 is a second perspective view of the UMA mounting plate of FIG. 11 , in accordance with the principles disclosed herein; [0028] FIG. 13 is a first perspective view of a plug interface board for the UMA shown in FIG. 6 , in accordance with the principles disclosed herein; [0029] FIG. 14 is a second perspective view of the UMA plug interface board in FIG. 13 , in accordance with the principles disclosed herein; [0030] FIG. 15 is a perspective view of the socket connector body of the UMA shown in FIG. 6 , in accordance with the principles disclosed herein; [0031] FIG. 16 is a second perspective sectional view of the socket connector body shown in FIG. 15 , in accordance with the principles disclosed herein; [0032] FIG. 17 is a first perspective view of a socket power board of the UMA shown in FIG. 6 , in accordance with the principles disclosed herein; [0033] FIG. 18 is a second perspective view of the UMA socket power board of FIG. 17 , in accordance with the principles disclosed herein; [0034] FIG. 19 is a first perspective view of a socket interface board for the UMA shown in FIG. 6 , in accordance with the principles disclosed herein; [0035] FIG. 20 is a second perspective view of the UMA socket interface board in FIG. 19 , in accordance with the principles disclosed herein; [0036] FIG. 21 illustrates a sectional view of a roll joint that may be incorporated into the robotic manipulator arm of FIG. 1 , in accordance with the principles disclosed herein; [0037] FIG. 22 is a perspective view of a proximal end cap for the roll joint of FIG. 21 to attach the UMA plug connector body of FIG. 7 , in accordance with the principles disclosed herein; [0038] FIG. 23 is perspective sectional view of the proximal end cap of FIG. 22 , in accordance with the principles disclosed herein; [0039] FIG. 24 is a perspective view of a distal end cap for the roll joint of FIG. 21 to attach the UMA socket connector body of FIG. 15 , in accordance with the principles disclosed herein; [0040] FIG. 25 is perspective sectional view of the distal end cap of FIG. 24 , in accordance with the principles disclosed herein; [0041] FIG. 26 is a perspective view of a pitch joint that may be incorporated into the robotic manipulator arm of FIG. 1 , in accordance with the principles disclosed herein; [0042] FIG. 27 illustrates a sectional view of the pitch joint in FIG. 26 , in accordance with the principles disclosed herein; [0043] FIG. 28 is a perspective view of automated detach/attach module (ADAM) that incorporates the UMA of FIG. 4 , in accordance with the principles disclosed herein; [0044] FIG. 29 is a side view of the combined UMA and automated detach/attach module of FIG. 28 , in accordance with the principles disclosed herein; [0045] FIG. 30 is a side view of an ADAM coupled to a portion of the robotic manipulator arm of FIG. 1 and coupled to an end-effector tool in accordance with the disclosure of FIG. 3 , for which the outline of a tool holder is shown; [0046] FIG. 31 is a perspective view of a position sensor assembly for a joint, such as the roll joint of FIG. 21 , in accordance with the principles disclosed herein; and [0047] FIG. 32 is a position-indicating label to be read by digital and analog sensors of the position sensor assembly of FIG. 31 , in accordance with the principles disclosed herein. DETAILED DESCRIPTION [0048] The following discussion is directed to various embodiments of the invention. The embodiments disclosed should not be interpreted or otherwise used as limiting the scope of the disclosure. One skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment. [0049] Certain terms are used in the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in interest of clarity and conciseness. In addition, like or identical reference numerals may be used to identify common or similar elements. However, for clarity in the figures, not every similar or common element will be identified. [0050] In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples or is coupled to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. [0051] The terms “system,” “assembly,” and “sub-assembly” may refer to a collection of two or more components, or elements, that are associated with one another and that may be coupled together. Furthermore, a system, assembly, or sub-assembly may be comprised of a collection of other, lesser systems, assemblies, or sub-assemblies. The terms “proximal” and “distal” will refer to the intended mounting location of an object or feature relative to the location of the main body of a robot or relative to the location of another supporting device. As such, proximal will describe an object or feature located closer to the main body of a robot as compared to a distal object or feature. [0052] FIG. 1 illustrates an embodiment of robotic manipulator arm 1 comprising one or more segments, or joints, 5 . When arm 1 is formed from multiple joints 5 , each joint 5 may be selectively coupled to an adjacent joint 5 by an interchangeable connector called a universal mating adapter (UMA) 100 , which is alternatively called a universal mechanical-electrical coupling (UMEC). In FIG. 1 , seven joints 5 are shown, but more or fewer joints 5 may be included in the configuration of a robotic manipulator arm like arm 1 . Examples of various types of joints 5 include a roll joint 20 and a pitch joint 60 , and will be explained in further detail in the disclosure below. The arm 1 may also include a UMA socket assembly 305 . FIG. 2 illustrates an integrated system, called robot 10 , comprising mobile robot base 11 , an arm 1 with one or more UMA 100 , and a robot controller 12 . Robot controller 12 includes software to govern the performance of robot 10 , including arm 1 and a tool 14 . One of the UMA 100 (not visible) couples the robot main base 11 to one end of arm 1 . Another UMA 100 may attach a tool, also called an end-effector, to the other end of arm 1 . In the example of FIG. 2 , gripping tool 14 is coupled to arm 1 . [0053] Another example of an end-effector is tool 85 in FIG. 3 , which, in this embodiment, is a scoop configured to collect a soil sample or to perform similar tasks. In other embodiments, tool 85 may instead incorporate a drill, a gripper, a saw, cameras, or another capability. Reference to tool 85 throughout the disclosure will assume that tool 85 has any one or more of these capabilities. In FIG. 3 , tool 85 is shown with a tri-lobe adapter plate 86 , which aids during removal and storage. Tool 85 may include sensors (not shown) to measure environmental conditions or tool performance or for diagnostics. If sensors are included in tool 85 , power and data signals can be exchanged with the robot controller 12 through manipulator arm 1 . [0054] UMA 100 is shown in FIGS. 4 and 5 . As identified in the exploded view of FIG. 6 , UMA 100 comprises two primary sub-assemblies: a first or proximal sub-assembly called a UMA socket assembly 305 and a second or distal sub-assembly called a UMA plug assembly 105 . [0055] Referring to FIG. 6 , UMA plug assembly 105 comprises several components: a generally annular plug connector body 120 (also FIG. 4 ), an internally threaded locking ring 160 , a power board 175 (also FIG. 4 ), a control board 180 (also FIG. 4 ), a mounting plate 190 , an o-ring 215 , an electrical plug interface board 220 , and a central axis 106 . Each component of plug assembly 105 will be explained in the following paragraphs. Subsequently, the assembly of these components will be explained. [0056] As shown in FIGS. 7 and 8 , the generally annular plug connector body 120 of UMA plug assembly 105 comprises a central axis 106 , a first or proximal end 123 , second or distal end 124 , cylindrical outer surface 126 , cylindrical inner surface 127 , a circumferential outer flange 130 , an inner flange 135 , generally rectangular mechanical bosses 140 , countersunk through-holes 146 , and generally trapezoidal recesses 148 . Outer flange 130 is disposed at the proximal end 123 of plug body 120 . Outer flange 130 comprises a distal end 132 and a cylindrical outer surface 131 . Inner flange 135 is disposed axially near the center of the inner surface 127 and extends radially inward from inner surface 127 . Inner flange 135 is characterized by a proximal surface 136 , a cylindrical inner surface 138 , and a seal gland 139 adjacent to proximal surface 136 . Mechanical bosses 140 extend axially away from proximal end 123 and in some aspect define a continuation of inner surface 127 . In the disclosed embodiment, plug body 120 has four mechanical bosses 140 . Other embodiments may have a different number of bosses or may have bosses of different shapes but functionally similar to bosses 140 . The end of each mechanical boss 140 includes an engagement tab 142 , which extends radially outward and might not extend back to proximal surface 123 . The engagement tabs 142 are uniquely placed on bosses 140 so that if plug body 120 is rotated about its central axis 106 , the new position of engagement tabs 142 will only match their original position if the angle of rotation of plug body 120 is a multiple of 360 degrees. This angular limitation insures that mechanical bosses 140 and their corresponding engagement tabs 142 only allow UMA plug assembly 105 and UMA socket assembly 305 to engage in a single orientation relative to one another. The coupling of plug assembly 105 and socket assembly 305 will be described in more detail at a later point in this disclosure. [0057] Continuing with plug connector body 120 in FIGS. 7 and 8 , countersunk through-holes 146 start at proximal end 123 and extend through distal end 124 to allow machine screws (not shown) to couple plug body 120 , and therefore all of UMA plug assembly 105 , to a joint 5 of robotic manipulator arm 1 . In depth, recesses 148 extend from proximal end 123 of plug body 120 to proximal surface 136 of inner flange 135 . In the radial direction, recesses 148 in plug body 120 extend outward from inner surface 127 . [0058] Returning to FIG. 6 , locking ring 160 includes a central axis 106 , a first or proximal end 163 , a second or distal end 164 , a cylindrical outer surface 166 , a cylindrical inner surface 168 , and a flange 170 . Additionally, threads 169 are cut into inner surface 168 . Flange 170 at distal end 164 extends radially inward and includes a generally smooth, inner proximal face 171 within ring 160 . Distal end 164 includes an external surface 165 that is perpendicular to central axis 106 . In the example of FIG. 6 , flange 170 includes a portion of external surface 165 . The external surface 165 is generally smooth in at least one embodiment. In at least one embodiment, cylindrical outer surface 166 may have dimples, knurling, or another form of rough surface (not shown) to improve the ability of operators and equipment to grip surface 166 . [0059] FIGS. 9 and 10 present power board 175 and control board 180 of plug assembly 105 , which are coupled by threaded fasteners 177 a and nuts 177 b , and are held at a fixed distance apart by spacers 178 . Power board 175 comprises a central axis 106 a first or proximal face 174 , a second or distal face 176 , one or more sets of power and data connector receptacles 179 , and a variety of multi-pin electrical connectors 184 . Receptacles 179 pass through power board 175 , extending beyond proximal face 174 and extending further beyond distal face 176 . Although not shown, power board 175 may also comprise power conditioning circuitry, fuses, internal circuitry, and other components to aid in routing electrical power and data signals to a coupled joint 5 or to a coupled tool 85 . [0060] Control board 180 comprises one or more integrated circuits and a variety of multi-pin electrical connectors 184 . Although not shown, control board 180 may also comprise fuses, internal circuitry, other integrated circuits, memory storage device(s), software, and other components to aid in managing a coupled joint 5 or a coupled tool 85 . When coupled to power board 175 , control board 180 is positioned nearest distal face 176 , and threaded fasteners 177 A extend beyond proximal face 174 . Some of the multi-pin electrical connectors 184 couple control board 180 to power board 175 . Other multi-pin electrical connectors 184 may couple with components, such as a motor or a sensor, of a joint 5 when a UMA plug assembly 105 is connected to a joint 5 or may couple to components of an end-effector tool (not shown). [0061] As indicated in FIG. 6 , a mounting plate 190 or a derivative of plate 190 may be incorporated into either a UMA plug assembly 105 or a UMA socket assembly 305 . As illustrated in FIGS. 11 and 12 , mounting plate 190 includes a central axis 106 , a first end 193 , a second end 194 , a first recessed face 195 , a second recessed face 196 , a generally cylindrical outer surface 198 , multiple external circumferentially-spaced tabs 202 , and a seal gland 204 . First end 193 , second end 194 , first recessed face 195 , and second recessed face 196 are perpendicular to central axis 106 . Seal gland 204 is radially disposed near first end 193 between the first recessed face 195 and outer surface 198 . More than one tab 202 is circumferentially-spaced along outer surface 198 . The exemplary embodiment of mounting plate 190 includes four tabs 202 . Each tab 202 includes a countersunk through-hole 203 , starting at first end 193 and extending through second end 194 . A generally rectangular recess 206 in face 195 is positioned off-center from central axis 106 . At least one through-hole 208 extends from recessed face 195 to recessed face 196 . In the example of plate 190 , four through-holes 208 are positioned towards the outer radial extent of recessed face 195 , approximately ninety degrees apart measured across axis 106 . At least one generally rectangular slot 210 extends from recessed face 195 through recessed face 196 as does at least one slot 212 . Slot 212 may be described as generally rectangular with the addition of wings, or smaller slots, that extend almost tangentially from either side of the primary slotted opening. In the example of plate 190 , two slots 210 are disposed on opposite sides of central axis 106 . Ninety degrees from these slots 210 are two of the slots 212 . [0062] Referring to FIGS. 13 and 14 , electrical plug interface board 220 of UMA plug assembly 105 comprises a central axis 106 , a first or proximal face 223 , a second or distal face 224 , an cylindrical outer surface 226 , one or more standoffs 228 , one or more sets of internal power and data pins 230 , and one or more sets of power and data transfer pins 232 , and one or more spring-loaded axially-extendable pins P 13 , P 14 . In the exemplary embodiment shown, four standoffs 228 are fixedly attached to board 220 closer to outer surface 226 than to central axis 106 and spaced 90 degrees from each other about axis 106 . Standoffs 228 pass through faces 223 , 224 , extending beyond proximal face 223 and extending further beyond distal face 224 . Two sets of power and data pins 230 , each with a plurality of pins, extend beyond face 224 on opposite sides of central axis 106 . Two sets of power and data transfer pins 232 , each with a plurality of pins, extend beyond face 223 on opposite sides of central axis 106 and displaced ninety degrees about axis 106 from the sets of pins 230 . Axially-extendable pins P 13 , P 14 are positioned on either side of one set of transfer pins 232 , extending beyond face 223 but not as far beyond face 223 as any of the pins 232 extend. When pins P 13 and P 14 engage a mating surface on a member of a UMA socket assembly 305 , power and data transfer between the mating plug assembly 105 and socket assembly 305 may be initiated. This coupling of plug assembly 105 and socket assembly 305 will be explained in more detail later in this disclosure. [0063] As arranged in FIG. 6 , A UMA plug assembly 105 may be compiled from the following parts, arranged generally in the order listed from the most distal to the most proximal component (left to right in FIG. 6 ): internally threaded locking ring 160 , plug connector body 120 , control board 180 , power board 175 , mounting plate 190 , O-ring 215 , and plug interface board 220 . In an assembly, locking ring 160 is positioned around a plug connector body 120 such that proximal face 171 of inner flange 170 on ring 160 ( FIG. 6 ) may abut the distal end 132 of outer flange 130 on plug body 120 ( FIG. 8 ). In this manner, locking ring 160 and plug connector body 120 are loosely engaged with axial and rotational degrees-of-freedom (DOF), i.e., the capability to move relative to one another in the stated directions. [0064] Another portion of plug assembly 105 will be considered next. As seen in FIG. 10 , a control board 180 is coupled near the distal face 176 of a power board 175 by threaded fasteners 177 A and nuts 177 B, separated by an appropriate distance with spacers 178 . The proximal ends of these threaded fasteners 177 B are aligned and positioned in through-holes 208 of a mounting plate 190 ( FIG. 12 ). The alignment includes the passing of the receptacles 179 on power board 175 through the slots 210 of mounting plate 190 . An O-ring 215 ( FIG. 6 ) seats within seal gland 204 near first end 193 which is positioned as the proximal side of the stated mounting plate 190 . Once aligned and abutted, the distal face 224 of a plug interface board 220 ( FIG. 14 ) seals against O-ring 215 to inhibit the passage of liquid or gas. In other words, as configured, a hermetically sealed barrier may be formed. Alignment of plug interface board 220 includes that insertion and coupling of fasteners 177 B in standoffs 228 . This description refers to the portion of fasteners 177 B that pass through mounting plate 190 . Internal data and power pins 230 slidingly engage receptacles 179 on power board 175 , which are disposed within slots 210 of mounting plate 190 . [0065] As may be inferred from FIG. 6 , tabs 202 of mounting plate 190 fit within recesses 148 of plug connector body 120 to be held by threaded fasteners (not shown) inserted through holes 203 and into body 120 . This arrangement forms a UMA plug assembly 105 . Power and data transfer pins 232 and axially-extendable pins P 13 and P 14 of interface board 220 extend from the proximal end of UMA plug assembly 105 as do mechanical bosses 140 of plug connector body 120 . These extending features ( 232 , P 13 , P 14 , 140 ) are available for engagement with a UMA socket assembly 305 . [0066] UMA socket assembly 305 of UMA 100 in FIG. 6 comprises multiple components: a generally annular socket connector body 320 (also FIG. 4 ), a power board 360 (also FIG. 4 ), a mounting plate 190 , an o-ring 215 , an electrical socket interface board 380 , and a central axis 306 . The components of socket assembly 305 will be explained in the following paragraphs. Subsequently, the assembly of these components will be explained. [0067] As shown in FIGS. 15 and 16 , the generally annular socket connector body 320 comprises a central axis 306 , a first or proximal end 323 , a second or distal end 324 , a generally cylindrical outer surface 326 , a generally cylindrical inner surface 327 , external threads 330 , an inner flange 335 , more than one multifaceted recess 340 , countersunk through-holes 346 , and generally trapezoidal recesses 348 . Flange 335 extends radially inward from inner surface 327 with the exterior surface 336 flush at proximal end 323 . Inner flange 335 is also characterized by a cylindrical inner surface 338 and a seal gland 339 adjacent to distal surface 337 . In depth, multifaceted recesses 340 extend from distal end 324 of socket connector body 320 to distal surface 337 of inner flange 335 . At distal end 324 , multifaceted recesses 340 include chamfered portions 341 . In the radial direction, multifaceted recesses 340 extend outward from inner surface 327 and may be considered to be an extension of inner surface 327 . In the disclosed embodiment, socket connector body 320 has four multifaceted recesses 340 ; although, other embodiments may have a different number of recesses functionally similar to recesses 340 . Each multifaceted recess 340 is shaped to slidingly engage and capture a particular mechanical boss 140 and a corresponding engagement tab 142 on plug connector body 120 ( FIG. 7 ). This engagement limitation insures that a UMA plug assembly 105 and a UMA socket assembly 305 engage in a single orientation relative to one another. [0068] Continuing with socket connector body 320 in FIGS. 15 and 16 , countersunk through-holes 346 start at distal end 324 and extend through proximal end 323 to allow machine screws (not shown) to coupled socket connector body 320 , and therefore all of UMA socket assembly 305 , to a joint 5 of robotic manipulator arm 1 . In depth, generally trapezoidal recesses 348 extend from distal end 324 of socket connector body 320 to distal surface 337 of inner flange 335 . In the radial direction, recesses 348 in socket connector body 320 extend outward from inner surface 327 . [0069] FIGS. 17 and 18 present power board 360 of socket assembly 305 comprises a central axis 306 , a first or proximal face 362 , a second or distal face 363 one or more sets of power and data connector receptacles 179 , a variety of multi-pin electrical connectors 184 and threaded fasteners 364 A and nuts 364 B. Although not shown, power board 360 may also comprise power conditioning circuitry, fuses, internal circuitry, electrical jumpers, and other components to aid in routing electrical power and data signals to a coupled joint 5 or to a coupled tool 85 . Receptacles 179 pass through power board 175 , extending beyond distal face 363 and extending further beyond proximal face 362 . Threaded fasteners 364 A extend beyond distal face 363 . Multi-pin electrical connectors 184 may couple components, such as a motor or a sensor, within a joint 5 when a UMA socket assembly 305 is connected to a joint 5 . [0070] Referring to FIGS. 19 and 20 , electrical socket interface board 380 of UMA socket assembly 305 comprises a central axis 306 , a first or proximal face 383 , a second or distal face 384 , an cylindrical outer surface 386 , one or more standoffs 388 , one or more sets of internal power and data pins 390 , one or more sets of power and data transfer receptacles 392 , and one or more electrical contacts C 13 , C 14 . In the exemplary embodiment shown, four standoffs 388 are fixedly attached to board 380 closer to outer surface 386 than to central axis 106 and spaced 90 degrees from each other about axis 306 . Standoffs 388 pass through faces 383 , 384 , extending beyond distal face 384 and extending further beyond proximal face 383 . Two sets of internal power and data pins 390 , each with a plurality of pins 390 , extend beyond face 383 on opposite sides of central axis 306 . Two sets of power and data transfer receptacles 392 , each with a plurality of pins 392 pass through faces 383 , 384 , extending beyond distal face 384 and extending further beyond proximal face 383 . The two sets of receptacles 392 are positioned on opposite sides of central axis 106 from each other and displaced ninety degrees about axis 106 from the sets of pins 390 . Two electrical contacts C 13 , C 14 are positioned on either side of one set of transfer pins 392 . Electrical contacts C 13 , C 14 are coupled to and nearly flush with face 384 . When pins P 13 and P 14 of plug interface board 220 ( FIG. 14 ) engage contacts C 13 , C 14 , power and data transfer between the mating plug assembly 105 and socket assembly 305 may be initiated. The coupling of plug assembly 105 and socket assembly 305 will be explained in more detail later in this disclosure. [0071] Referring to the exploded view in FIG. 6 , UMA socket assembly 305 may be compiled from the components previously described, arranged generally in the order listed next. The order proceeds from the most proximal to the most distal component, i.e., from right to left in FIG. 6 . The components are: a socket connector body 320 , a power board 360 , a mounting plate 190 , an o-ring 215 , and a socket interface board 380 . To form a socket assembly 305 , the axes 306 for all components 320 , 360 , 190 , and 380 are aligned. As will be explained, other features dictate the necessary angular (rotational) alignment of components 320 , 360 , 190 , and 380 . The socket connector body 320 forms a foundation for the socket assembly 305 . The other referenced components coupled to the distal end 324 of body 320 . [0072] The threaded fasteners 364 A extending from the distal face 363 of power board 360 ( FIG. 17 ) are configured to pass through the holes 208 of mounting plate 190 ( FIG. 11 ) and couple with standoffs 388 on socket interface board 380 ( FIG. 20 ). Additional alignment interactions will now be described. When a sub-assembly is coupled as just described, second end 194 of mounting plate 190 ( FIG. 11 ) faces distal face 363 of power board 360 , making second end 194 the proximal end for the plate 190 in a socket assembly 305 , which is the opposite of a plate 190 in a plug assembly 105 ( FIG. 6 ). Correspondingly, first end 193 ( FIG. 12 ) is positioned toward the most distal component, the socket interface board 380 . An O-ring 215 ( FIG. 6 ) seats within seal gland 204 on mounting plate 190 , facing socket interface board 380 . Once aligned and abutted, proximal face 383 of a socket interface board 380 ( FIG. 20 ) seals against the o-ring 215 to inhibit the passage of liquid or gas. In other words, as configured, a hermetically sealed barrier may be formed. Additionally, receptacles 179 on power board 360 extend through the slots 210 of mounting plate 190 without contacting slot 210 and slidingly engage the internal power and data pins 390 extending from proximal face 383 on socket interface board 380 . Power and data transfer receptacles 392 pass into slots 212 on mounting plate 190 without contacting slot 212 and without contacting power board 360 . [0073] With power board 360 and socket interface board 380 mutually coupled to mounting plate 190 , tabs 202 of plate 190 ( FIG. 12 ) fit within recesses 348 of socket connector body 320 ( FIG. 15 ) to be held by threaded fasteners (not shown) inserted through holes 203 and into body 320 . This arrangement forms a UMA socket assembly 305 . Power and data transfer receptacles 392 , electrical contacts C 13 , C 14 , and multifaceted recesses 340 of the distal face 384 of socket interface board 380 are available for engagement with a UMA plug assembly 105 as are external threads 330 of connector body 320 . [0074] Referring to FIGS. 5 and 6 , the universal mating adapter (UMA) 100 comprises a UMA plug assembly 105 and UMA socket assembly 305 . In some embodiments, assemblies 105 and 305 are coupled. In other embodiments, assemblies 105 and 103 are not coupled. To couple assemblies 105 and 305 , axes 106 and 306 are aligned, and each mechanical boss 140 on plug connector body 120 ( FIG. 7 ) is aligned with a prescribed multifaceted recess 340 on socket connector body 320 ( FIG. 15 ). Assemblies 105 and 305 are moved axially toward one another. In the early stages of contact between 105 and 305 , minor misalignment between bosses 140 and recesses 340 may be corrected by the chamfered portions 341 at the edge of recesses 340 , which are configured to guide the entry of bosses 140 . When mechanical bosses 140 are aligned with and are partially within recesses 340 , power and data transfer receptacles 392 on socket interface board 380 ( FIG. 19 ) slidingly receive power and data transfer pins 232 on interface board 220 ( FIG. 14 ) of plug assembly 105 . Therefore, bosses 140 and recesses 340 have a self-aligning, self-correcting capability to protect pins 232 from being bent during the coupling of a UMA. When plug assembly 105 and socket assembly 305 are axially closer and have greater contact between receptacles 392 and pins 232 , then axially-extendable pins P 13 , P 14 ( FIG. 14 ) touch electrical contacts C 13 , C 14 ( FIG. 19 ), respectively, to form a combined and operative electrical interface between the electrical interfaces 220 , 380 . [0075] If plug assembly 105 or socket assembly 305 is energized during the coupling process, the receptacles 392 and the mating pins 232 are inactive until pins P 13 , P 14 connect with electrical contacts C 13 , C 14 . The contact of pins P 13 , P 14 with electrical contacts C 13 , C 14 may initiate power and data transfer between receptacles 392 and mating pins 232 . Similarly for de-coupling or disconnecting, a plug assembly 105 and socket assembly 305 of a coupled UMA 100 are configured to be de-energized when disconnection is initiated. So, during disconnection and while disconnected, the plug assembly 105 and socket assembly 305 pair are de-energized. In this scenario, power and data transfer between receptacles 392 and the mating pins 232 will cease when pins P 13 , P 14 cease to mate with electrical contacts C 13 , C 14 , which will occur before the receptacles 392 and the mating pins 232 disconnect. As a consequence of these characteristics, UMA 100 is “hot swappable,” meaning a plug assembly 105 and a socket assembly 305 may be connected or disconnected while one or both assemblies 105 , 305 is energized. [0076] When assembled as shown in FIGS. 4 and 5 , the universal mating adapter (UMA) 100 is configured to transfer force and torque loads between an external object connected to plug connector body 120 , and an another external object connected to socket connector body 320 . One or more of the external objects may be a joint 5 . UMA 100 is also configured to transfer power and data signals between the power board 360 and the pair that includes control board 180 and power board 175 . Power board 360 may also couple and exchange power and data signals with an external object, such as one of the previously referenced joints 5 . Control board 180 and power board 175 may individually or collectively couple and exchange power and data signals with an external object, such as a joint 5 . [0077] As introduced earlier in relation to FIG. 1 , robotic manipulator arm 1 comprises a series of joints 5 , each configured to be selectively coupled to an adjacent joint 5 with a UMA 100 . That is to say the plug assembly 105 on a first joint 5 is configured to couple to the socket assembly 305 of a second, adjacent joint 5 . The locking ring 160 of the plug assembly 105 is configured to engage threadingly with the socket connector body 320 of the socket assembly 305 and thereby to hold firmly together (i.e., to lock) the assemblies 105 , 305 and the accompanying joints 5 . [0078] The embodiment of FIG. 1 includes two types of joints 5 in manipulator arm 1 , named according to the type of motion each one is configured to perform. The first type of joint, the roll joint 20 , is illustrated in greater detail in FIG. 21 . The second type of joint, the pitch joint 60 , is illustrated in greater detail in FIGS. 26 and 27 . Various other embodiments include one type of joint 5 or more than two types of joints 5 . Thus, other embodiments of manipulator arm 1 may include other types of joints 5 , such as a joint configured for linear extension or retraction. Some embodiments may include a joint that is configured as a combination of or a variation of roll joint 20 and pitch joint 60 . [0079] The various joints 5 may vary in size depending on the task or location of the joint. A joint 5 that is coupled directly to a robot or is mounted in a more proximal location to the robot may be larger and stronger than other joints 5 that are more distal. A more proximal joint 5 must be configured to support the weight, force, and torque loads of any joints 5 that may be mounted beyond the proximal joint 5 . A distal joint 5 has less load to support than a more proximal joint 5 , and so the distal joint 5 may be sized smaller, if appropriate for the intended task. This disclosed size variation may be implemented for joints 20 , 60 or any other type of joint 5 that is used. Depending on the location, size, or intended purpose of particular a joint 5 , 20 , 60 , the joint may be described as a shoulder, elbow, wrist, or base joint 5 , 20 , 60 . Such a designation is intended for convenience when discussing a joint and is not intended to describe a limitation of the joint. [0080] UMA 100 is configured as a common connector to couple the various pairs of adjacent joints 5 , 20 , 60 in manipulator arm 1 , whether the multiple joints 5 , 20 , 60 are similar in size or differ in size. A plug assembly 105 connects to the proximal end, and a socket assembly 305 connects to the distal end of each joint 5 , 20 , 60 . [0081] With the inclusion of a UMA 100 , two joints may be coupled or uncoupled manually without tools, i.e., in a tool-free manner, and without an external power source. Because all joints use the same connector, i.e., UMA 100 , the order of the joints 5 , 20 , 60 in a manipulator arm 1 may be rearranged, and the number of joints 5 , 20 , 60 can be changed as compared to FIG. 1 , making manipulator arm 1 reconfigurable and scalable. Within the plug assembly 105 of the UMA 100 coupled to each joint 5 , 20 , 60 , the control board 180 is configured to exchange configuration parameters and other data with the control boards 180 coupled to adjoining joint(s) 5 , 20 , 60 . The exchanged parameters from each joint may include the type of joint, range of motion, gear transmission ratio, length of joint, mass of joint, the zero angular location (“home”) of the joint, sensor information, and possibly other pertinent information. The parameters and other data may also be exchanged with a controller, such as robot controller 12 in FIG. 2 . Power boards 175 and 360 in each UMA 100 pass power and aid with the parameter and data exchange to and from joints 5 , 20 , 60 . Power, parameters, and data may also be transmitted for an end-effector, such as gripping tool 14 or and embodiment of tool 85 . The exchange of these parameters and data facilitates the capability to remove joints from, to add joints to, and to rearrange the sequence of joints within arm 1 without reprogramming or recompiling the software running in control boards 180 or the software running in controller 12 . Controller 12 is configured to automatically recognize and control one or more joints 5 , 20 , 60 even after the quantity or sequence of joints has been altered. [0082] Next, the specifications for a roll joint 20 and for a pitch joint 60 will be explained. In the descriptions, reference will be given to a base section and to a rotatable or movable section of the joint 20 , 60 . The base section is intended to be coupled more proximal the robot 10 or another mounting device than is the rotatable section of the same joint 20 , 60 . Thus, the base section refers to the portion of a joint 20 or 60 that is intended couple to the robot directly or to couple to the robot indirectly through one or more joints more proximal. The rotatable section is attached to the base section and is the portion of the joint that is configured to be moved relative to the base section. For example, for a joint 20 , 60 that is directly coupled to the robot, the base section of that joint is configured to remain stationary relative to the robot when the joint operates to move the other, rotatable section. For joints 20 , 60 that couple indirectly to the robot by means of intervening joints, the base section remains stationary relative to the robot if all intervening joints remain stationary. However, in some situations, it is possible for a base section to move while the corresponding rotatable section remains stationary. In general, the base section and the rotatable section of a joint are configured to move relative to each other. More generally, one or both sections of a joint 20 , 60 on an arm 1 are configured to move relative to a fixed coordinate system (not shown) due to the movement of one or more joints 5 in the manipulator arm 1 , due to the movement of robot 10 when coupled to arm 1 , or due to outside forces. [0083] A cross-sectional view of a roll joint 20 is illustrated in FIG. 21 . Roll joint 20 comprises a central axis 21 , a first or proximal end 23 , a second or distal end 24 , a base section 25 , a rotatable section 35 , a motor 40 , a gear mechanism, such as harmonic drive 45 , a brake assembly 50 , one or more rotational bearings 56 , and a central wiring tube 58 . Base section 25 includes an external shell 26 , an internal shell 28 , and a proximal end cap 30 . End cap 30 is configured to couple a UMA plug assembly 105 at the proximal end 23 of joint 20 , as exemplified on the right side of FIG. 21 . Views of end cap 30 are shown in FIGS. 22 and 23 . On the outer surface of external shell 26 , an external recess 27 offers a location to insert a removable magnet 53 to release the grip of brake assembly 50 . The location for recess 27 shown in FIG. 21 is one of many possible locations within base section 25 . Rotatable section 35 includes an external shell 36 and a distal end cap 38 . End cap 38 is configured to couple with a UMA socket assembly 305 at the second or distal end 24 of joint 20 , as exemplified on the left side of FIG. 21 . Views of end cap 38 are shown in FIGS. 24 and 25 . [0084] Hollow-core motor 40 , which may be a brushless direct current (DC) motor, comprises a generally annular stator 44 surrounding a generally annular rotor 42 , which is mounted on a hollow-core rotor coupling 43 . Motor axis 41 is aligned with central axis 21 . At one end, bearing 56 A rotationally couples rotor coupling 43 to external shell 26 of base section 25 . The other end of rotor coupling 43 is coupled to an annular, elliptically-shaped wave generator 46 of harmonic drive 45 . Continuing to explain harmonic drive 45 , wave generator 46 may rotate and may induce rotational motion in bearing 56 C and may cause the external gear teeth 47 G on a flexspline 47 to movably mesh against a small number of the internal gear teeth 48 G on stationary circular spline 48 . Circular spline 48 is fixed to internal shell 28 of base section 25 . Therefore, when wave generator 46 rotates, the rotation induces a slower rotation in flexspline 47 with respect to stationary circular spline 48 . Flexspline 47 is fixed to section 35 of joint 20 by fasteners (not shown) located in through-holes 39 . Therefore, if flexspline 47 rotates, section 35 also rotates. In addition, section 35 is rotationally coupled to base section 25 by one or more bearings 56 B. With this configuration, section 35 may rotate about axis 21 and move relative to section 25 with or without the energized aid of motor 40 . [0085] Continuing to refer to roll joint 20 in FIG. 21 , hollow-core brake assembly 50 comprises a brake rotor 54 A and a brake stator 54 B. In at least one embodiment, brake assembly 50 is equivalent to Kendrion model 86-61104H00. Brake rotor 54 A is affixed to rotor coupling 43 . Brake stator 54 B is affixed to proximal end cap 30 of base section 25 . In the disclosed embodiment, brake assembly 50 is electrically actuatable and is configured for fail-safe operation. The fail-safe configuration means that the brake engages and inhibits rotation of rotor 54 A relative to stator 54 B when electrical power is removed or lost. The brake 50 may also be engaged when power is supplied and commanded to engage. For the brake 50 to engage, a portion of rotor 54 A would move toward and contact stator 54 B, developing friction. When brake 50 engages, rotor coupling 43 , harmonic drive 45 , rotatable section 35 , and any other connected components achieve a less movable configuration with respect to base section 25 . The less movable configuration may result in a slower rotational speed or a fixed, non-moving condition. For section 35 to rotate relative to section 25 of pitch joint 20 , brake 50 is energized and activated to release the frictional engagement of rotor 54 A and stator 54 B. [0086] Another feature is the inclusion of magnetic brake release switch 51 , which is distinct from brake 50 but is functionally coupled to the brake 50 . Brake release switch 51 is configured with the ability to release the hold of brake assembly 50 when joint 20 is appropriately energized. As stated, releasing the engagement of brake 50 allows section 35 of joint 20 to move relative to base section 25 . Release switch 51 is located inside base section 25 near external recess 27 of proximal outer shell 26 . [0087] A method for actuating switch 51 to release the hold of brake assembly 50 is to place a removable magnet 53 in external recess 27 . A ferrous metal member 52 located near switch 51 holds magnet 53 in place and concentrates the lines of magnetic flux of magnet 53 , making it more effective in activating switch 51 . Other braking mechanisms with similar functionality may be employed in joint 20 or any joint 5 , 60 . [0088] Within roll joint 20 , central wiring tube 58 is coaxial with axis 21 and extends through the hollow cores of motor 40 , harmonic drive 45 , brake assembly 50 , rotator coupling 43 , and various other annular features (e.g., bearings 56 ) without hindering the rotation of the stated features. Central wiring tube 58 provides a place for installing electrical wires and other elongate features (not shown) that may extend between base section 25 and rotatable section 35 without being disturbed by the multiple revolutions of the motor 40 , harmonic drive 45 , brake assembly 50 , or other annular features. Any of the electrical wires and other elongate features contained in tube 58 may extend between a UMA plug assembly 105 and a UMA socket assembly 305 for power and data exchange. Electrical wires and other elongate features in tube 58 facilitate the exchange of parameters and data between base section 25 and rotatable section 35 of a single joint 20 or between any combination of joints 5 , 20 , 60 , a tool 85 , robot controller 12 , or similarly connected components. [0089] A pitch joint 60 is illustrated in FIG. 26 . A cross-section of pitch joint 60 is presented in FIG. 27 . Pitch joint 60 comprises a joint axis 61 , a first or proximal end 63 , a second or distal end 64 , a base section 65 , a rotatable section 75 , a motor 40 , a gear mechanism, such as harmonic drive 45 , a brake assembly 50 , one or more rotational bearings 56 , and a central wiring tube 84 . Base section 65 includes an external shell 68 an internal shell 70 , an end cover 71 , and a side cover 72 . Covers 71 , 72 are removable to provide access for maintenance. Internal shell 70 is affixed to external shell 68 . Base section 65 also includes a first or proximal mounting axis 66 , which is perpendicular to joint axis 61 . As exemplified on the bottom of FIGS. 26 and 27 , base section 65 is configured to couple a UMA plug assembly 105 at the proximal end 63 of pitch joint 60 , having the central axis 106 aligned with the proximal mounting axis 66 . On the outer surface of base section 65 , external recess 69 offers a location to insert a removable magnet 53 to release the grip of brake assembly 50 . One possible location for recess 69 is shown in FIG. 27 . Rotatable section 75 includes an external shell 78 , an end cover 81 , and a side cover 82 . Covers 81 , 82 provide access for maintenance. Rotatable section 75 also includes a second or distal mounting axis 76 , which is perpendicular to joint axis 61 . As exemplified on the top of FIGS. 26 and 27 , rotatable section 75 is configured to couple a UMA socket assembly 305 at the distal end 64 of pitch joint 60 , having the central axis 306 aligned with the distal mounting axis 76 . [0090] Continuing to reference FIG. 27 , within pitch joint 60 , the a hollow-core motor 40 is coupled to internal shell 70 and is coupled to rotatable section 75 through a harmonic drive 45 in a similar fashion and for a similar function as another motor 40 is installed within a roll joint 20 , as previously described in reference to FIG. 21 . Returning to FIG. 27 , motor axis 41 is aligned with joint axis 61 . In addition, section 75 is rotationally coupled to base section 65 by one or more bearings 56 B. With this configuration, section 75 may rotate about joint axis 61 and thereby move relative to section 65 with or without the energized aid of the motor 40 . [0091] A fail-safe brake assembly 50 within pitch joint 60 couples base section 65 and rotational section 75 in a similar fashion and for a similar function as brake assembly 50 within roll joint 20 . When brake 50 engages rotatable section 75 and any other connected components of pitch joint 60 , rotatable section 75 achieves a less movable configuration with respect to base section 65 . The less movable configuration may result in a slower rotational speed or a fixed, non-moving condition. Brake 50 may be energized and activated to release section 75 to rotate relative to section 65 . Other features and functions of a brake assembly 50 , a release switch 51 , a ferrous metal member 52 , and a removable magnet 53 were explained previously in relation to roll joint 20 and may be similarly applied to pitch joint 60 . [0092] Within pitch joint 60 , central wiring tube 84 is coaxial with axis 21 and extends through the hollow cores of motor 40 , harmonic drive 45 , brake assembly 50 , and various other annular features (e.g., rotor coupling 43 , bearings 56 ) without hindering the rotation of the stated features. Central wiring tube 84 provides a place for installing electrical wires and other elongate features (not shown) that may extend between base section 65 and rotatable section 75 without being disturbed by the multiple revolutions of the motor 40 , harmonic drive 45 , brake assembly 50 , or other annular features. Any of the electrical wires and other elongate features contained in tube 58 may extend between a UMA plug assembly 105 and a UMA socket assembly 305 for power and data exchange. Electrical wires and other elongate features in tube 58 facilitate the exchange of parameters and data between base section 65 and rotatable section 75 of a single joint 60 or between any combination of joints 5 , 20 , 60 , a tool 85 , robot controller 12 , or similarly connected components. [0093] Pitch joint 60 has a symmetric range of motion in both directions. For example, rotatable section 75 may start in the un-bent, “home” position shown in FIG. 26 and rotate about joint axis 61 and relative to base section 65 , rotating through an angle in one direction (for example, clockwise) to the maximum extent that section 75 is configured to travel. Next, section 75 may return to the “home” position and rotate through an angle in the opposite, counter-clockwise direction to the maximum extent that section 75 is configured to travel. Because pitch joint 60 is configured with a symmetric range of motion, the maximum angle travelled in the clockwise direction will equal or nearly equal the maximum angle travelled in the counter-clockwise direction. The symmetric configuration of pitch joint 60 may permit a closed-form solution for the inverse kinematics when planning a path of motion for robotic arm 1 and may reduce the need to unwind the joints 5 when traveling along certain trajectories, i.e., paths of travel. Similarly, roll joint 20 may be configured with a symmetric range of motion in both directions. [0094] Some embodiments of the disclosed equipment may include sensors to evaluate and respond to force feedback, environmental conditions, joint rotation, joint extension, sense of touch, or other conditions. The sensors may include hall-effect sensors, rotational encoders, strain gauges, or other sensing components. The sensors may be coupled to a joint 5 or to a tool 85 . [0095] Referring now to FIGS. 21 and 27 , within each joint 20 , 60 , an optical encoder and rotating disc pair 530 is axially aligned with a motor 40 and one or more axes 21 , 61 , 41 and configured to track the rotational position and speed of rotor 42 and rotor coupling 43 with respect to a base section 25 , 65 . Each joint 20 , 60 includes a position sensor assembly 500 and a position-indicating label 520 configured to track the rotational position and, if desired, the speed of rotatable section 35 , 75 with respect to base section 25 , 65 . More clearly seen in FIG. 31 , position sensor assembly 500 comprises an angular position sensor 505 , a home sensor 510 , an electrical coupling 512 , stand-off legs 514 , and a mounting pad 516 . Sensors 505 , 510 are mounted to one surface of pad 516 and the legs 514 are attached to the opposite surface of pad 516 . Returning to FIGS. 21 and 27 , the legs 514 of position sensor assembly 500 may be attached to the cylindrical outer surface of an internal shell 28 , 70 of a base section 25 , 65 , respectively. In this location, sensors 505 , 510 are near the inner surface of an external shell 36 , 78 of a rotatable section 35 , 75 , respectively, where position-indicating label 520 is affixed, facing toward sensors 505 , 510 . An embodiment of label 520 is shown FIG. 32 . The gradient-shaded region 522 extends the entire length of label 520 and therefore may encompass the entire inner circumference of an external shell 36 , 78 . When installed, gradient-shaded region 522 is intended to be aligned with angular position sensor 505 . The single stripe, i.e., solid line, 523 on label 520 is intended to be aligned with home sensor 510 . The other linear markings on label 520 may be used to align the label during installation. [0096] Referring to FIGS. 31 and 32 , home sensor 510 may be an optical emitter-sensor pair capable of generating a change in electrical output when the light intensity reflected from an adjacent surface changes by a prescribed threshold. Sensor 510 is configured to generate one level of signal for a light-colored region (e.g., white) and a second signal level for a darker region (e.g., black) such as solid line 523 . In some embodiments, home sensor 510 is a digital optical sensor. If a joint 20 , 60 is energized and activated, sensor 510 may indicate the one particular angular position of a rotatable section 35 , 75 with respect to a base section 25 , 65 , respectively, wherein solid line 523 is adjacent to sensor 510 . This particular angular position may be described as the “home position” of the joint. For a pitch joint 60 , as an example, the home position may be configured to be the position in which the distal mounting axis 76 of section 75 is aligned with proximal mounting axis 66 of section 65 . [0097] Referring still to FIGS. 31 and 32 , angular position sensor 505 may be an optical emitter-sensor pair capable of generating an electrical output proportional to a varying intensity of light reflected from an adjacent surface, such as gradient-shaded region 522 . Therefore, if a joint 20 , 60 is energized and activated, sensor 505 may indicate the angular position of a rotatable section 35 , 75 with respect to a base section 25 , 65 , respectively. In some embodiments sensor 505 is an analog optical sensor. The range of sensitivity of sensor 505 and the shading spectrum of region 522 on label 520 are configured to give a unique output signal for any angular configuration of joint 20 , 60 ; therefore, sensor 505 may be described as an absolute position sensor. As an absolute sensor, sensor 505 may not require calibration or confirmation each time the joint 20 , 60 is initially energized and activated. However, the home signal from home sensor 510 may be used as a redundant confirmation or as an extra calibration aid for angular position sensor 505 if desired. [0098] In other embodiments, position sensor 505 and home sensor 510 may be implemented using another principle for generating and detecting variable or discretely (i.e., distinctly) changing signals based on the relative angular position of two rotatably coupled members, such as, for example, sections 25 and 35 of joint 20 or sections 65 and 75 of joint 60 . For example, sensor 505 may respond to a variation in capacitance induced from a position-indication label that has a dielectric strip of varying width in place of the gradient-shaded region 522 of label 520 . Similarly, as an example, home sensor 510 may be a capacitance sensor with a one or more discrete dielectric elements configured to pass within range of sensor 510 . [0099] FIGS. 28 , 29 , and 30 illustrate an embodiment of an auto-detach/attach mechanism (ADAM) 600 that may couple a tool 85 , also called an end-effector, with the distal end, e.g., end 24 , 64 , of the most distal joint, which may be a joint 5 , 20 , 60 , of a manipulator arm 1 . ADAM 600 includes two portions 605 , 625 that may be coupled or decoupled. First portion 605 includes a modified end cap 610 for a socket and a UMA socket assembly 305 . Second portion 605 includes a modified end cap 630 for a plug and a UMA plug assembly 105 . Modified end cap 610 is generally cylindrical and comprises a central axis 611 , a cylindrical outer surface 612 , a first or proximal end 613 , a second or distal end 614 , one or more wheel assemblies 615 , and one or more motors 624 . Modified end cap 610 may be a modified version of an end cap 38 ( FIG. 24 ) for the distal end 24 of a roll joint 20 , or modified end cap 610 may be configured for the distal end 64 of a pitch joint 60 . When an ADAM 600 attaches to a roll joint 20 , the modified end cap 610 replaces or obviates the use of an end cap 38 . [0100] Each wheel assembly 615 includes an axis 616 , a wheel bracket 617 , a rotatable shaft coupling 618 , which may be a ball-bearing assembly, a shaft 620 , and a wheel 622 . The rotatable shaft coupling 618 , shaft 620 , and wheel 622 are aligned along the common axis 616 . Wheel 622 is rotationally fixed to one end of shaft 620 . Shaft 620 is inserted and axially fixed inside rotatable shaft coupling 618 , which is affixed to wheel bracket 617 . In this configuration, wheel 622 and shaft 620 are free to rotate together relative to wheel bracket 617 as allowed by rotatable shaft coupling 618 . [0101] The example of FIGS. 28 and 29 illustrates an ADAM 600 with three wheel assemblies 615 and one motor 624 . The three wheel assemblies 615 are coupled to and evenly spaced around the circumference of outer surface 612 at the distal end 614 of modified end cap 610 . More specifically, wheel brackets 617 are coupled to the modified end cap 610 and may extend inside the outer surface 612 to facilitate the coupling. The wheel assembly axes 616 , and consequently shafts 620 , are aligned with central axis 611 of modified end cap 610 . The shaft (not independently numbered) of motor 624 is coupled to the shaft 620 of one wheel assembly 615 , or the motor 624 shaft is integral with the shaft 620 of one wheel assembly 615 . In this configuration, motor 624 may drive the coupled wheel 622 , which is also called the driven-wheel 622 A. The outer surface of driven-wheel 622 A is called the motor-driven surface 623 A. The wheels 622 on the wheel assemblies 615 that have no motor may rotate when contacted by a moving object. These wheels with no coupled motor are called idler wheels 622 B. [0102] As best seen in FIG. 29 , in the first portion 605 , a UMA socket assembly 305 is coupled to the distal end 614 of modified end cap 610 . Central axis 306 of assembly 305 is aligned and collinear with central axis 611 . Wheels 622 extend beyond the end 614 . A portion of the outer, contact surface of wheels 622 is axially aligned with external threads 330 on socket assembly 305 . The remainder of the contact surface of wheels 622 extends a distance “X” beyond threads 330 . [0103] Referring still to FIG. 29 , the second portion 625 of ADAM 600 comprises a UMA plug assembly 105 coupled to the proximal end 633 of a modified end cap 630 . Modified end cap 630 is generally cylindrical and comprises a central axis 631 , a first or proximal end 633 , a second or distal end 634 , and a plurality of spring-loaded engagement pins 636 . Modified end cap 630 may be a modified version of a proximal end cap 30 ( FIG. 22 ) as used at the proximal end 23 of a roll joint 20 , or modified end cap 630 may be configured uniquely to match the requirements of a particular tool 85 that may couple at distal end 634 . Engagement pins 636 are circumferentially spaced around proximal end 633 . Pins 636 are configured to press against and slidingly contact the smooth, external surface 165 of the locking ring 160 in UMA plug assembly 105 . [0104] As exemplified in FIG. 30 , ADAM 600 is configured to couple an end-effector, such as a tool 85 , to a manipulator arm 1 at the most distal joint, which, for example, may be a joint 20 . In general, another type of joint 5 , 20 , 60 may be used, and the joint may be alone, not connected to a complete manipulator arm. A coupling process will be described, but the process is only exemplary of the performance of ADAM 600 . The components are not required to be coupled to constitute an ADAM 600 . In the example of FIG. 30 , the two portions 605 , 625 of ADAM 600 are contacting one another or are coupled. A tool 85 couples the distal end 634 of modified end cap 630 while a joint 20 couples the proximal end 613 of modified end cap 610 . To achieve this configuration, axis 611 is first aligned with axis 631 . Plug connector body 120 ( FIG. 7 ) axially engages socket connector body 320 ( FIG. 15 ). This action brings locking ring 160 in proximity to the external threads 330 of body 320 and in proximity to wheels 622 , including motor-driven surface 623 A. Engagement pins 636 push ring 160 toward threads 330 . When motor 624 is activated, motor-driven surface 623 A engages ring 160 causing ring 160 to rotate around axis 611 . Consequently, ring 160 may rotate idler wheels 622 B. Idler wheels 622 B are configured to supply radial, reactive forces to keep ring 160 centered on axis 611 and threads 330 . The rotating action engages threads 169 ( FIG. 6 ) of locking ring 160 with threads 330 , driving ring 160 upward (in the view of FIG. 30 ) toward modified end cap 610 and joint 20 . The coupling of a tool 85 (representing any compatible end-effector) to the end of a joint 20 may be accomplished automatically, without human interaction, when using an ADAM 600 augmented by a tool holder, such as tool holder 90 that grips tri-lobe adapter plate 86 on tool 85 . With an ADAM 600 , tool 85 may also be manually installed or removed without activating motor 624 S. Alternatively, tool 85 may be manually coupled to a joint 5 , 20 , 60 by standard end caps 30 , 38 (or an equivalent interconnection) and a UMA 100 . [0105] Although the disclosed embodiment includes a motor-driven surface 623 A as part of a driven-wheel 622 A, in other embodiments, motor-driven surface 623 A may be part of a rotating belt, a reciprocating arm, the teeth of a ratchet, or another member that engages ring 160 . [0106] While disclosed embodiments have been shown and described, modifications thereof may be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the invention. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters may be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. [0107] The arrangement and features of UMA 100 components may be modified in some embodiments. As exemplified in FIG. 6 , one or more embodiments have been disclosed in which a plug assembly 105 is located on the distal end of a UMA 100 and a socket assembly 305 is on the proximal end. In these embodiments, for example FIG. 21 and FIG. 26 , a plug assembly 105 would be installed at the proximal end of joint 5 , 20 , 60 , and a socket assembly 305 would be installed at the distal end of each joint 5 , 20 , 60 . In other embodiments, some components of plug assembly 105 or an entire a plug assembly similar to assembly 105 may be arranged to be at the proximal end of a UMA 100 , and some components of socket assembly 305 or an entire a socket assembly similar to assembly 305 may be arranged to be at the distal end of a UMA 100 . The relative locations of assemblies 105 , 305 on adjacent joints 5 , 20 , 60 would be swapped accordingly.

A robotic manipulator arm is disclosed. The arm includes joints that are attachable and detachable in a tool-free manner via a universal mating adapter. The universal mating adapter includes a built-in electrical interface for an operative electrical connection upon mechanical coupling of the adapter portions. The universal mating adapter includes mechanisms and the ability to store and communicate parameter configurations such that the joints can be rearranged for immediate operation of the arm without further reprogramming, recompiling, or other software intervention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, in particular, one suitable for operation in a vapour-compression refrigerating cycle which uses a refrigerant, such as CO 2 , in a supercritical area thereof. 2. Description of the Related Art A conventional scroll compressor generally comprises a casing; a fixed scroll and a revolving scroll in the housing, each scroll comprising an end plate and a spiral protrusion built on an inner surface of the end plate, said inner surface facing the other end plate so as to engage the protrusions of each scroll and form a spiral compression chamber. In this structure, the introduced working gas is compressed in the compression chamber and then discharged according to the revolving operation of the revolving scroll. In order to secure enough (large) space for the compression chamber, the height of each spiral protrusion of the fixed scroll and revolving scroll is larger than the height of each end plate. As for the vapour-compression refrigerating cycle, one of the recently proposed measures to avoid the use of Freon (fron, a refrigerant) in order to protect the environment is the use of a refrigerating cycle using CO 2 as the working gas (i.e., the refrigerant gas). This cycle is called “CO 2 cycle” below. An example thereof is disclosed in Japanese Examined Patent Application, Second Publication, No. Hei 7-18602. The operation of this CO 2 cycle is similar to the operation of a conventional vapour-compression refrigerating cycle using Freon. That is, as shown by the cycle A →B→C→D→A in FIG. 5 (which shows a CO 2 Mollier chart), CO 2 in the gas phase is compressed using a compressor (A→B), and this hot and compressed CO 2 in the gas phase is cooled using a gas cooler (B→C). This cooled gas is further decompressed using a decompressor (C→D), and CO 2 in the gas-liquid phase is then vaporized (D→A), so that latent heat with respect to the evaporation is taken from an external fluid such as air, thereby cooling the external fluid. The critical temperature of CO 2 is approximately 31° C., that is, lower than that of Freon, the conventional refrigerant. Therefore, when the temperature of the outside air is high in the summer season or the like, the temperature of CO 2 at the gas cooler side is higher than the critical temperature of CO 2 . Therefore, in this case, CO 2 is not condensed at the outlet side of the gas cooler (that is, line segment B-C in FIG. 3 does not intersect with the saturated liquid curve SL). In addition, the condition at the outlet side of the gas cooler (corresponding to point C in FIG. 3) depends on the discharge pressure of the compressor and the CO 2 temperature at the outlet side of the gas cooler, and this CO 2 temperature at the outlet side depends on the discharge ability of the gas cooler and the outside temperature (which cannot be controlled). Therefore, substantially, the CO 2 temperature at the outlet side of the gas cooler cannot be controlled. Accordingly, the condition at the outlet side of the gas cooler (i.e., point C) can be controlled by controlling the discharge pressure of the compressor (i.e., the pressure at the outlet side of the gas cooler). That is, in order to keep sufficient cooling ability (i.e., enthalpy difference) when the temperature of the outside air is high in the summer season or the like, higher pressure at the outlet side of the gas cooler is necessary as shown in the cycle E→F→G→H→E in FIG. 3 . In order to satisfy this condition, the operating pressure of the compressor must be higher in comparison with the conventional refrigerating cycle using Freon. In an example of an air conditioner used in a vehicle, the operating pressure of the compressor is 3 kg/cm 2 in case of using R 134 (i.e., conventional Freon), but 40 kg/cm 2 in case of CO 2 . In addition, the operation stopping pressure of the compressor of this example is 15 kg/cm 2 in case of using RI 34 , but 100 kg/cm 2 in case of CO 2 . In such a scroll compressor using CO 2 as the working gas and having high operating pressure, if the thickness of each end plate of the fixed scroll and revolving scroll is smaller than the height of each spiral protrusion of the fixed and revolving scrolls, each end plate tends to bend and be deformed due to a load generated in the compression operation, so that the sealing ability of the compression chamber is degraded. As a result, the (amount of) discharge may be decreased due to the leakage of the working gas from the compression chamber, or the temperature of the discharge gas may rise due to recompression of the leaked gas, so that degradation of the performance of the compressor is inevitable. SUMMARY OF THE INVENTION In consideration of the above circumstances, an objective of the present invention is to provide a scroll compressor with which there is no leakage of the working gas from the compression chamber, in which deformation of each end plate of the fixed scroll and revolving scroll is prevented. Therefore, the present invention provides a scroll compressor comprising: a casing; a fixed scroll provided in the housing and comprising an end plate and a spiral protrusion built on one face of the end plate; and a revolving scroll provided in the casing and comprising an end plate and a spiral protrusion built on one face of the end plate, wherein the spiral protrusions of each scroll are engaged with each other so as to form a spiral compression chamber, wherein: a working gas introduced in the casing is compressed in the compression chamber and then discharged according to the revolving operation of the revolving scroll; and given thickness T 1 of the end plate of the fixed scroll, thickness T 2 of the end plate of the revolving scroll, height H 1 of the spiral protrusion of the fixed scroll, and height H 2 of the spiral protrusion of the revolving scroll, the following condition is satisfied: T 1 >0.9H 1 T 2 >0.9H 2 According to the above scroll compressor, even in a scroll compressor having a considerably high operating pressure, the end plates of the fixed scroll and revolving scroll are not easily deformed when the end plates receive a load generated in the compression operation, and thus the sealing ability of compression chamber is not degraded. As a result, the (amount of) discharge is not decreased due to the leakage of the working gas from the compression chamber, and the temperature of the discharge gas does not rise due to recompression of the leaked gas, so that the performance of the compressor is improved. Preferably, ribs for reinforcing the fixed scroll and the revolving scroll are respectively provided at the back face side of each scroll. Accordingly, even if the thickness of the end plate is smaller than the height of the spiral protrusion, that is, smaller than an originally defined size, rigidity equivalent to that obtained by the structure having the originally defined size can be obtained. Therefore, the performance of the compressor can be further improved. Preferably, the working gas is carbon dioxide. In this case, the present invention can be effectively applied to a scroll compressor which uses a refrigerating cycle using CO 2 as the working gas, and which has a high operating pressure. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view in the longitudinal direction of an embodiment of the scroll compressor according to the present invention. FIGS. 2A and 2B show an example structure of the revolving scroll, where FIG. 2A is a plan view of the revolving scroll, and FIG. 2B is a view observed from the lower side of the structure as shown in FIG. 2 A. FIGS. 2C and 2D show another example structure of the revolving scroll, where FIG. 2C is a plan view of the revolving scroll, and FIG. 2D is a view observed from the lower side of the structure as shown in FIG. 2 C. FIG. 3 is a graph showing experimental results which show a relationship between thickness T 1 (=T 2 ) of the end plates of the fixed and revolving scrolls and indicated efficiency η i . FIG. 4 is a diagram showing a vapour-compression refrigerating cycle. FIG. 5 is a Mollier chart for CO 2 . DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the scroll compressor according to the present invention will be explained with reference to the drawings. First, the CO 2 cycle (structure) including the scroll compressor according to the present invention will be explained with reference to FIG. 4 . The CO 2 cycle S in FIG. 4 is applied, for example, to the air conditioner of a vehicle. Reference numeral 1 indicates a scroll compressor for compressing CO 2 in the gas phase. This scroll compressor 1 receives driving force from a driving power supply (not shown) such as an engine. Reference numeral 1 a indicates a gas cooler for heat-exchanging CO 2 compressed in the scroll compressor 1 and outside air (or the like), so as to cool CO 2 . Reference numeral 1 b indicates a pressure control valve for controlling the pressure at the outlet side of the gas cooler 1 a according to the CO 2 temperature at the outlet side of the gas cooler 1 a . CO 2 is decompressed by the pressure control valve 1 b and restrictor 1 c , and CO 2 enters into the gas-liquid phase (i.e., in the two-phase state). Reference numeral 1 d indicates an evaporator (i.e., heat absorber) as an air cooling means in the cabin of the vehicle. When CO 2 in the gas-liquid two-phase state is vaporized (or evaporated) in the evaporator 1 d , CO 2 takes heat (corresponding to the latent heat of CO 2 ) from the air in the cabin so that the air in the cabin is cooled. Reference numeral 1 e indicates an accumulator for temporarily storing CO 2 in the gas phase. The scroll compressor 1 , gas cooler 1 a , pressure control valve 1 b , restrictor 1 c , evaporator 1 d , and accumulator 1 e are connected via piping 1 f so as to form a closed circuit. An embodiment of the scroll compressor 1 will be explained with reference to FIG. 1 . Housing (or casing) 1 A of scroll compressor 1 includes cup-like main body 2 , and front case (i.e., crank case) 4 fastened to the main body 2 via bolt 3 . Reference numeral 5 indicates a crank shaft which pierces the front case 4 and is supported via main bearing 6 and sub bearing 7 by the front case 4 in a freely-rotatable form. The rotation of the engine (not shown) of the vehicle is transmitted via a known electromagnetic clutch 32 to the crank shaft 5 . Reference numerals 32 a and 32 b respectively indicate the coil and pulley of the electromagnetic clutch 32 . In the housing 1 A, fixed scroll 8 and revolving scroll 9 are provided. The fixed scroll 8 and revolving scroll 9 are made of, for example, an aluminum-based or cast iron-based material. The fixed scroll 8 comprises end plate 10 and spiral protrusion (i.e., lap) 11 disposed on a surface of the plate 10 , and the surface facing end plate 17 explained later. A ring-shaped back pressure block 13 is detachably attached to the back face of end plate 10 by using a plurality of bolts 12 as fastening means. O rings 14 a and 14 b are provided (or embedded) in the inner-peripheral and outer-peripheral faces of the back pressure block 13 . These O rings 14 a and 14 b closely contact the inner-peripheral face of main body 2 of the casing, and high-pressure chamber (discharge chamber, explained later) 16 is separated from low-pressure chamber 15 (suction chamber) in the main body 2 of the casing. The high-pressure chamber 16 consists of a space surrounded by smaller-diameter face 13 a of the back pressure block 13 , a space surrounded by larger-diameter face 13 b of the back pressure block 13 , this space being formed continuously with the above space surrounded by face 13 a , and a space surrounded by concave portion 10 a formed in the back face of the end plate 10 of fixed scroll 8 , this space being formed continuously with the above space surrounded by face 13 b . In the end plate 10 of fixed scroll 8 , discharge port 34 (i.e., top clearance) is opened, and discharge valve 35 for opening/closing this discharge port 34 is provided in the concave portion 10 a. The revolving scroll 9 comprises end plate 17 and spiral protrusion (i.e., lap) 18 which is disposed on a surface of the plate 17 , the surface facing the end plate 10 . The shape of the spiral protrusion 18 is substantially the same as that of the spiral protrusion 11 of the fixed scroll 8 . One of the distinctive features of the present embodiment is that thickness T 1 of end plate 10 of fixed scroll 8 is larger than 0.9 times as much as height H 1 of spiral protrusion 11 , and, more specifically, approximately 1.7 times as much as height H 1 . Similarly, thickness T 2 (=T 1 ) of end plate 17 of revolving scroll 9 is larger than 0.9 times as much as height H 2 (=H 1 ) of spiral protrusion 18 , and, more specifically, approximately 1.7 times as much as height H 2 . A ring-shaped plate spring 20 a is provided between the fixed scroll 8 and the main body 2 of the casing. A plurality of predetermined positions of the plate spring 20 a are alternately fastened to the fixed scroll 8 and to the main body 2 via bolts 20 b . According to this structure, the fixed scroll 8 can move only in its axial direction by the (amount of) maximum flexure of plate spring 20 a in the axial direction (i.e., a floating structure). The above ring-shaped plate springs 20 a and bolts 20 a form fixed scroll supporting apparatus 20 . Between the portion protruding from the back face of the back pressure block 13 and housing 1 A, gap C is provided, so that the back pressure block 13 can move in the axial direction described above. The fixed scroll 8 and the revolving scroll 9 are engaged in a manner such that the axes of these scrolls are eccentrically separated from each other by the radius of revolution (that is, in an eccentric form), and the phases of these scrolls differ from each other by 180° (refer to FIG. 1 ). In addition, tip seals (not shown), provided and buried at the head surface of spiral protrusion 11 , are in close contact with the inner surface (facing the end plate 10 ) of end plate 17 , while tip seals (not shown), provided and buried at the head surface of spiral protrusion 18 , are in close contact with the inner surface (facing the end plate 17 ) of end plate 10 . Furthermore, the side faces of the spiral protrusions 11 and 18 contact each other at some positions so that enclosed spaces 21 a and 21 b are formed essentially at positions of point symmetry with respect to the center of the spiral. In addition, rotation-preventing ring (i.e., Oldham coupling) 27 for permitting the revolving scroll 9 to revolve, but prohibiting the rotation of the scroll 9 is provided between the fixed scroll 8 and revolving scroll 9 . A boss 22 is provided on (or projects from) a central area of the outer surface of the end plate 17 . A freely-rotatable drive bush 23 is inserted in the boss 22 via revolving bearing (or drive bearing) 24 which also functions as a radial bearing. In addition, a freely-rotatable eccentric shaft 26 , projecting from the inner-side end of the crank shaft 5 , is inserted in through hole 25 provided in the drive bush 23 . Furthermore, thrust ball bearing 19 for supporting the revolving scroll 9 is provided between the outer-circumferential edge of the outer surface of end plate 17 and the front case 4 . A known mechanical seal (i.e., shaft seal) 28 used for sealing a shaft is provided around the crank shaft 5 , and this mechanical seal 28 comprises seat ring 28 a fixed to the front case 4 , and slave ring 28 b which rotates together with crank shaft 5 . This slave ring 28 b is forced by forcing member 28 c towards seat ring 28 a and closely contacts the seat ring 28 a , so that the slave ring 28 b rotationally slides on the seat ring 28 a in accordance with the rotation of the crank shaft 5 . Another distinctive feature of scroll compressor 1 of the present embodiment is that, as shown in FIGS. 2A and 2B, a plurality of (e.g., 6 ) ribs 50 , functioning as reinforcements, are provided in a radial form at the back face side of the end plate 17 of revolving scroll 9 . In the back face of the end plate 17 , the protruding ribs 50 are provided in a ring-shaped area having a predetermined width around boss 22 , where a slide face having a predetermined width (on which ribs 50 are not provided) remains at the outer-peripheral side of the end plate 17 . According to the above structure of providing ribs 50 at the revolving scroll 9 side, even if the thickness of the end plate 17 is smaller than the height of the spiral protrusion 18 , that is, smaller than an originally defined size, rigidity equivalent to that obtained by the structure having the originally defined size can be obtained. The structure of the ribs is not limited to the above form as shown in FIGS. 2A and 2B, but another structure as shown in FIGS. 2C and 2D is possible, in which a plurality of ribs 52 are also provided in a radial form at the back face side of the end plate 17 of revolving scroll 9 . In this case, the ribs are formed by providing a plurality of concave portions 51 in a ring-shaped area having a predetermined width around boss 22 , where a slide face having a predetermined width (in which concave portions 51 are not provided) remains at the outer-peripheral side of the end plate 17 . That is, the ribs 52 are formed in the end plate 17 in this case. Similarly, ribs functioning as reinforcements are also provided in a radial form at the fixed scroll 8 side. The operation of the scroll compressor 1 will be explained below. When the rotation of the vehicle engine is transmitted to the crank shaft 5 by energizing the coil 32 a of the electromagnetic clutch 32 , the revolving scroll 9 is driven by the rotation of the crank shaft 5 , transmitted via the revolution driving mechanism consisting of eccentric shaft 26 , through hole 25 , drive bush 23 , revolving bearing 24 , and boss 22 . The revolving scroll 9 revolves along a circular orbit having a radius of revolution, while rotation of the scroll 9 is prohibited by the rotation-preventing ring 27 . In this way, line-contact portions in the side faces of spiral protrusions 11 and 18 gradually move toward the center of the “swirl”, and thereby enclosed spaces (i.e., compression chambers) 21 a and 21 b also move toward the center of the swirl while the volume of each chamber is gradually reduced. Accordingly, the working gas (refer to arrow A), which has flowed into suction chamber 15 through a suction inlet (not shown), enters enclosed space 21 a from an opening at the ends of the spiral protrusions 11 and 18 and reaches center space 21 c while the gas is compressed. The compressed gas then passes through discharge port 34 provided in the end plate 10 of the fixed scroll 8 , and opens discharge valve 35 , so that the gas is discharged into high-pressure chamber 16 . The gas is further discharged outside via discharge outlet 38 . In this way, according to the revolution of the revolving scroll 9 , the fluid introduced from the suction chamber 15 is compressed in the enclosed spaces 21 a and 21 b , and this compressed gas is discharged. When the energizing process for coil 32 a of electromagnetic clutch 32 is released so as to stop transmission of the rotating force to crank shaft 5 , the operation of the scroll compressor 1 is stopped. When the coil 32 a of electromagnetic clutch 32 is energized again, the scroll compressor 1 is activated again. In the above-explained structure of the scroll compressor 1 , the thickness T 1 (=T 2 ) of end plates 10 and 17 of the fixed scroll 8 and revolving scroll 9 is relatively smaller than 0.9 times as much as height H 1 (=H 2 ) of the spiral protrusions 11 and 18 . Therefore, even in a scroll compressor having a considerably high operating pressure, the end plates 10 and 17 of the fixed scroll 8 and revolving scroll 9 are not easily deformed when the end plates receive a load generated in the compression operation, and thus the sealing ability of compression chamber 20 is not degraded. As a result, the (amount of) discharge is not decreased due to the leakage of the working gas from the compression chamber 20 , and the temperature of the discharge gas does not rise due to recompression of the leaked gas, so that the performance of the compressor is improved. FIG. 3 is a graph showing experimental results which show a relationship between thickness T 1 (=T 2 ) and indicated efficiency η i , where efficiency η i is a ratio of theoretical power to the sum of theoretical power and indicated power loss (which means power loss caused by leakage of the working gas). As shown in the graph, if T 1 is 0.9 H 1 , or less, indicated efficiency η i , remarkably decreases. Therefore, in the present embodiment, thickness T 1 , is set to be larger than 0.9 H 1 , and similarly, thickness T 2 is set to be larger than 0.9H 2 . In particular, a smaller scroll compressor is required for the air conditioner of a vehicle; thus, the height (i.e., thickness) of each end plate of the fixed and revolving scrolls is limited and is preferably T 1 (=T 2 )<3H 1 (=H 2 ). In the above explained embodiment, the scroll compressor is applied to the CO 2 cycle using CO 2 as the working gas; however, the application is not limited to this type, and the compressor according to the present invention can be applied to the vapour-compression refrigerating cycle using a conventional working gas such as Freon.

A scroll compressor with which there is no leakage of the working gas from the compression chamber is disclosed, in which deformation of each end plate of the fixed scroll and revolving scroll is prevented. The scroll compressor comprises a casing; a fixed scroll provided in the housing and comprising an end plate and a spiral protrusion built on one face of the end plate; and a revolving scroll provided in the casing and comprising an end plate and a spiral protrusion built on one face of the end plate, wherein the spiral protrusions of each scroll are engaged with each other so as to form a spiral compression chamber. In the structure, a working gas introduced in the casing is compressed in the compression chamber and then discharged according to the revolving operation of the revolving scroll; and given thickness T 1 of the end plate of the fixed scroll, thickness T 2 of the end plate of the revolving scroll, height H 1 of the spiral protrusion of the fixed scroll, and height H 2 of the spiral protrusion of the revolving scroll, the following condition is satisfied: T 1 >0.9H 1 , and T 2 >0.9H 2 .

CROSS RELATED APPLICATIONS This application is a continuation of application Ser. No. 280,074, filed July 2, 1981, and now abandoned. BACKGROUND OF THE INVENTION After the Second World War, so-called corrugated paper boards have been widely spread as packaging materials from the field of paperboard box to the field of wooden caskets. They are also widely used as various cushioning materials. On the other hand, as the progress of mechanization of transportation handling as well as scale-up of machinery, transportation units are growing larger to thereby cause startling changes in transportation circumstances. For example, for conveying cargoes using a fork lift truck, wooden pallet forks have conventionally been used. But, as a part of rationalization in circulation of goods, slip sheets have recently been used in place of these pallets. A slip sheet has a thickness of about 1 to 5 mm, and is made of a sheet of paperboard, fiberboard or synthetic resin sheet, having the same size as the wooden pallet (e.g. 1100×1100 mm), provided with a flap portion with a width of about 60 to 120 mm. This flap, which is simply shaped in a form of a sheet being bent in the direction of handling, may disadvantageously be deformed with ease when gripped by the gripper equipped on the fork lift truck. Also, the sheet material itself constituting a slip sheet is deficient in rigidity, and hence cannot stand sufficiently the load of cargoes and may sometimes be deformed to cause sagging of cargoes, etc. Corrugated paper boards are also used as cushioning materials for cargoes. But also, in this case, when the load is too great, the corrugated portion is completely crushed down to render the corrugated board nothing but a mere flat paper board. For enhancement of rigidity, there may be employed a corrugated sheet made of a synthetic resin to solve the problem all at once. But, when it is bent to form a flap portion, various troubles may be caused during usage due to lack of flexibility at the bent portion. The bent portion is generally formed by heating the portion to be bent by pressing a heat bar on one side thereof, which is in turn bent by about 15° to 30°. Since fusion occurs only at the liner portion on the heated side, the bent portion after cooling is fixed at the bent angle, showing substantially no flexibility for bending. For this reason, when for example a corrugated sheet of a synthetic resin is used as slip sheet, there may sometimes be caused fracture at the bent portion when the flap portion of a slip sheet having loaded cargoes is drawn by gripping with a gripper to be unnaturally deformed. Such a slip sheet is found, for example, in the Japanese Patent Laid-Open Public Disclosure No. 144564/1977. Similar inconveniences may also occur when there are piled on the floor slip sheets having loaded cargoes and further slip sheets having loaded cargoes are to be placed side by side by means of a fork lift truck. In this case, the flap portions protruded from the cargoes on the side of already placed slip sheets (it is necessary for next conveying to have the flap portions thus exposed) may be contacted with those to be newly arranged, whereby the flaps may be pressed by the cargoes to be broken at the bent portions or increased in the bent angle to be made difficult in handling for the next time. The cargoes may also be broken in such a case. These troubles can be avoided by taking sufficient intervals between arrays of cargoes, but storage efficiency is thereby markedly lowered. SUMMARY OF THE INVENTION An object of the present invention is to provide a corrugated board-like sheet made of a synthetic resin (hereinafter referred to merely as corrugated sheet) having a desirable compression strength, comprising a composite having liners on both upper and lower sides and an interlining core which holds space between said liners and is fused to both of said liners, and a flap provided continuous to said composite through an intermediary flute having a certain width, said flute being formed at least at one end thereof by integral fusion of the liners and the interlining core. Another object of the present invention is to provide a corrugated sheet, wherein said flute portion has a hinge effect. Still another object of the present invention is to provide a corrugated sheet for use as a slip sheet for conveying of a cargoes or as a cushioning material for packaging having greater compression resistance. Further, it is also another object of the present invention to provide a corrugated sheet, constituted of a resin material selected from polyethylene, ethylene-propylene copolymer containing not more than 40 mole % of ethylene, and blend of polyethylene and polypropylene with polyethylene content of 50% by weight or less. Still further object of the present invention is to provide a corrugated sheet for use as a slip sheet, wherein the surface of the upper liner has a non-slip structure. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a slant view of one example of a corrugated sheet according to the present invention; FIG. 2 shows the cross-sectional view taken along the line A--A in FIG. 1; FIGS. 3 through 8 show slant views partially cut of corrugated sheets to be used for preparation of the corrugated sheets according to the present invention, respectively; FIG. 9 shows a cross-sectional view of a preferred embodiment in FIG. 7; and FIG. 10 shows a cross-sectional view of one embodiment of a corrugated sheet according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT The corrugated sheet according to the present invention, as apparently seen from the examples shown in FIG. 1 and FIG. 2, comprises a corrugated sheet 3 having upper and lower liners 1 and 1' fused on both sides of the interlining core 2 interposed therebetween and has an integrally fused portion 5, wherein the liners 1, 1' and interlining core 2 are heat pressed to be integrally fused into one layer along a continuous line across the corrugated sheet laminate, at a desired position from at least one end of said sheet, and a flap portion 4 capable of being bent through said integrally fused portion 5 connected thereto. The interlining core may have any desired shape and structure, which are not particularly limited. It may be constituted, for example, as illustrated in the slant views partially cut shown in FIGS. 3 through 7 as 2(or 2'). Liners 1, 1' and interlining core 2(or 2') may be molded separately from each other, followed by integral fusion thereof. Alternatively, the whole composite can be molded as one sheet by means of injection molding, etc. Among them, the interlining core having a number of projections as illustrated in FIG. 7 will give a surface of corrugated sheet with slightly swelled portions at the top 3, as shown in FIG. 9, whereby non-slip effect can preferably be imparted to the surface. The height of the swelled parts may be 1 to 40 percent of the total thickness of the sheet, preferably 10 to 15 percent. If the height will be over 40 percent, the stiffness of the sheet may be decreased, while if it will be lower than 0.1%, the above purpose cannot be achieved. FIG. 10 shows the cross-sectional view of a corrugated sheet according to the present invention, particularly at the flute 14, which is the connecting part with the flap portion. Thus, the bottom of the flute 14 is constituted of an integrally made portion in which liners 11, 11' and interlining core 12 are pressed together under heating to be provided with properties like one sheet, whereby excellent hinge effect can be obtained For the use of slip-sheet a surface of liner 1(or 11) is preferably of matted finish in view of preventing to slip cargoes off. The matted finish will be 1 to 20 of gloss value according to the method of ASTM D523, preferably 1 to 10. On the contrary, a surface of liner 1'(11') which faces to a floor is of polished finish in view of less friction on the floor. The polished finish will be 30 to 80 of gloss value, preferably 50 to 70. The liners and the interlining core of these corrugated sheets may each be constituted of a molded product of polyethylene, polypropylene, ethylene-propylene resinous copolymer, polyamide or blends of these with ethylene-propylene rubbery copolymer or ethylene-propylene-diene rubbery copolymer. Among them, molded products of polyethylene, ethylene-propylene copolymer containing not more than 40 mole % of ethylene and blend of polyethylene with propylene containing not more than 50% by weight of polyethylene are particularly preferred. The materials for the liners and for the interlining core may either be the same or different, but it is required that both materials can be fused together by heat pressing. Usually, they are all made of the same material. Corrugated sheets generally employed have a total thickness of about 3 to 10 mm, preferably about 4 to 6 mm. For example, a corrugated sheet having a thickness of 5 mm will have a unit weight of about 900 g/m 2 . The liners and the interlining core constituting such a corrugated sheet may have thicknesses such that, when one liner (generally the liner on the floor side of slip sheet) is made to have a thickness of 1, the other liner has a thickness in terms of relative ratio of 1.5 to 2.0 and the interlining core of about 1.5 to 3.0. On said other liner (generally the liner on the loaded side of slip sheet), there may be provided for non-slip purpose a nonwoven fabric, preferably a spun-bonded nonwoven fabric or net, of polypropylene or polyamide having, for example, a unit weight of 10 to 200 g/m 2 , preferably about 50 to 150 g/m 2 to be laminated by heat fusion or with an adhesive, followed by bending working thereof. The interliner core is generally arranged in parallel to the side of the corrugated sheet, but it may also be arranged in a slanted direction by 5° to 60°, preferably 15° to 45°. The flap to be provided on such a corrugated sheet of the present invention is generally a single flap type, but there may also be employed depending on uses a double flap type, a three flap type or a four flap type, having flaps provided on the adjacent or confronting sides of the sheet. Bending for formation of such a flap portion may be performed by integral fusion of the liners and the interlining core. In case of a double flap type, a three flap type or a four flap type, when the flaps are used for reinforcement of the end portions of packaging material, it is desired to provide a cutting in one of the bending portions 5 of the common flap portion to the crossing point thereof. A width of the bending portion 5 is formed in 0.5 to 4 times of the sheet thickness, preferably 0.8 time to double thereof. Such an integral fusion may be conducted in preparation of a corrugated sheet, but it is generally performed after preparation of the corrugated sheet to press the sheet with a heat bar equipped with a heater for heating, thereby effecting fusion integrally of liners and interlining core. A heat bar employed may differ depending on the bending angle, which is generally set at about 5° to 60°, preferably about 10° to 30°, and the thickness of the corrugated sheet. But there may generally be used a heat bar rounded at the tip portion, having a thickness of about 3 to 15 mm, preferably about 5 to 8 mm. Fusion may be generally effected at a temperature of about 150° to 250° C., preferably about 160° to 200° C., under a surface pressure of about 0.3 kg/cm 2 or more for about 5 to 20 seconds. And, preferably immediately after fusion, bending may be repeated for several times, whereby so called hinge effect can strongly be exhibited to enhance also the strength. As shown in FIG. 10, pressing by means of a heat bar is generally effected only on the side of one liner 11 (the liner on the loaded side of slip sheet) together with interlining core 12, thereby forming a thin laminated portion 13 on the side of the other liner 11' and also a flute portion 14 thereat which enables bending. But it is also possible to effect pressing of the heat bar from both sides of the liners. In the corrugated sheet having the flap portion connected through a bending portion of integrally fused liners and interlining core, it can be first pointed out that improvement in strength of the bending portion is effected. That is, the load on the bending portion is received by the entire thickness of the integrally made portion. Therefore, the strength can clearly be improved as compared with the case when the load is imposed only on the bending portion formed substantially by the liner on one side, namely only on a part of the thickness of the corrugated sheet. Further, due to appearance of the hinge effect as mentioned above, the breaking strength will not be lowered to a great extent even by performing repeated bendings. In addition, when the corrugated sheet of the present invention having the flap connected through such a bending portion is used as slip sheet in storage working for piling of cargoes by a fork lift truck, there occurs no accident of breaking by contact of the cargoes with the flap exposed from beneath of the cargoes, since the flap can be bent relatively freely at the bending portion. Moreover, the flap exposed from beneath of the cargoes can be bent vertically along the line of the piled cargoes, and hence the piled cargoes can be placed with no interval to result in the increase of the storage quantity of cargoes to maximum. As an additional advantage, when conveying the slip sheets themselves, they can be piled flat without damaging whole slip sheet including the flap portion and can also, if desired, carry cargoes thereon to increase remarkably transportation efficiency. When the corrugated sheet of the present invention is used as reinforcing material for packaging, the corner portions of cargoes can completely be protected with the flap. The present invention is to be explained in further detail by referring to the following Examples. EXAMPLE 1 A corrugated sheet as shown in FIG. 7 was prepared from an ethylene-propylene copolymer (density: 0.9 g/cm 3 , Melt Index: 1.3 g/10 min., ethylene content: 30 mole %). The liners had thicknesses of 0.2 mm and 0.4 mm, respectively, and the interlining core a thickness of 0.4 mm. As a whole, the corrugated sheet had a thickness of 5 mm, a width of 1400 mm, a length of 1250 mm and a unit weight of 900 g/m 2 . At 80 mm from the end in the direction of length of this corrugated sheet, there was pressed a heat bar heated to 200° C., with dimensions of 5 mm in thickness and 1500 mm in length having a tip portion rounded at a curvature of radius of 5 mm, under a pressure of 0.3 kg/cm 2 for 15 seconds to form a bending portion in which each liner and the interlining core were integrally fused. For measurement of the strength of the bending portion, there was prepared a test strip having a width of 20 mm and a length of 70 mm, in which the integrally fused portion is located in the center in the direction of length. And, using Instron universal testing machine, the load at break was measured under the conditions of chuck interval of 5 cm and tensile speed of 200 mm/min. to obtain a value of 30.4 kg. Also for measurement of the hinge characteristic of the bending portion, a test strip of 20 mm in width and 70 mm in length was subjected to the hinge test at a hinge angle of 270°. After bending was repeated 1000 times and 10000 times at the rate of 175 times per minute, the loads at break were measured to be 28.7 kg and 27.6 kg, respectively. EXAMPLE 2 Similarly as in Example 1, a corrugated sheet was prepared from a high density polyethylene (density: 0.954 g/cm 3 , Melt Index: 0.90 g/10 min.), and the bending portion was formed according to the same procedures. But, the heat bar was heated to 180° C. and the pressing time was 8 seconds. The load at break of the bending portion formed was found to be 23.0 kg, and the load at break after the hinge test repeated 1000 times 20.6 kg. COMPARATIVE EXAMPLE In Example 1, heat fusion by means of the heat bar is effected only on the liner portion on one side of the corrugated sheet to form a bending at an angle of 30°. The load at break of the bending portion formed was found to be 24.5 kg and that after the hinge test repeated 1000 times 18.6 kg.

This invention relates to a corrugated board-like sheet made of a synthetic resin. More particularly, it relates to a corrugated board-like sheet made of a synthetic resin having a flap portion with hinge effect.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to orthopedic devices and methods therefor, and more specifically relates to improved orthopedic pillow support devices used to hold, support, cushion and immobilize a patient's injured arm or a patient's arm with respect to a patient's injured shoulder and methods therefor. 2. Description of the Related Art In the past, various types of orthopedic devices were created to support an arm and/or shoulder during post-surgical or non-surgical recovery from injury. These devices are often used prior to surgery as well. For example, to aid in the healing of and to provide relief to a shoulder suffering from any number of ailments such as a rotator cuff injury, sprains, dislocations, humeral fractures and other injuries, it is critical to stabilize and immobilize the respective forearm and upper arm at a desired position with respect to the injured shoulder to prevent shoulder joint movement. It is further necessary to position the arm away from the upper torso at an abduction angle that is most conducive to reducing shoulder joint stress. It is also important to provide such support during both waking and sleeping hours while providing the utmost comfort and convenience to the patient. The prior art includes a number of orthopedic devices for supporting an arm and shoulder. For example, one familiar device is the arm sling. It is simply comprised of material in which an arm, typically bent at the elbow at approximately a ninety degree angle, is placed and a shoulder strap for holding the material and arm in place. This type of device provides minimal arm and shoulder support but provides no immobilization of the arm and shoulder joints. It also generally does not provide cushioning for comfort. U.S. Pat. No. 4,373,517 describes a device that supports an arm and immobilizes a shoulder. It is essentially a metal brace comprised of multiple rigid assemblies mounted to a patient's torso to support a rigid horizontal member, which, in turn, supports an arm in a horizontal-only position. This device suffers from numerous drawbacks. It is a complex device comprised of many rigid, metal parts and is consequently bulky, heavy, uncomfortable and not conducive for wearing over long periods of time. Furthermore, it limits the position of the arm to substantially the horizontal plane making it inflexible and unable to be worn in the recumbent (lying down) position. Therefore, a patient who needed the benefits of this device around the clock had to either remove the device to sleep in the recumbent position or sleep in an uncomfortable upright position. Another orthopedic device developed was a shoulder immobilizer which provided a sling-type apparatus to hold an arm and a separate pillow device wrapped around a patient's waist upon which the arm rests. Weaknesses of this two piece device are that it is only utilized for post-surgery situations and is not designed for recumbent use. Moreover, none of the prior devices provided much versatility in terms of their application to a variety of injuries and conditions, flexibility of positioning the arm with respect to the patient's body, ease of use, and comfort, all in one device. Accordingly, there existed a definite need to provide a new orthopedic support device that would be useful for a shoulder injury, arm injury or both, portable and lightweight, extremely comfortable to wear, easy to attach to the body, reversible for attachment to either the left arm and shoulder or right arm and shoulder, adjustable to the size of the patient and to the desired position, and easier and less costly to manufacture. This device would be versatile enough for use in a wide variety of orthopedic applications ranging from non-surgical type arm or shoulder sprains, dislocations and fractures to post-surgical recovery periods such as that after a rotator cuff surgery or other shoulder surgeries. Furthermore, since patients who must wear the devices of the prior art to sleep must remain in the upright, sitting position, it was especially important to provide a device that could be worn in the recumbent, as well as upright, positions. SUMMARY OF THE INVENTION In accordance with one embodiment of this invention, it is an object of this invention to provide an improved, reversible, orthopedic arm and shoulder support device that immobilizes both the shoulder and arm joints and provides abduction of the arm for reducing shoulder joint stress. It is another object of this invention to provide a new orthopedic pillow support device that is light, low cost, easy to attach to the body and comfortable to wear. It is a further object of this invention to provide an orthopedic arm and shoulder pillow device for use while the patient is in the recumbent, as well as upright, positions. It is yet another object of this invention to provide a method for a new and improved, reversible, orthopedic arm and shoulder support device that immobilizes both the shoulder and arm joints. BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with one embodiment of this invention, an orthopedic pillow device for supporting and immobilizing a patient's arm relative to a patient's shoulder is disclosed comprising, in combination, a portable, reversible, pillow support means for selective attachment to one of the patient's right arm and left arm and the patient's upper torso, wherein the support means comprises an L-shape pillow means for providing support and cushioning for both a lower and upper portion of the arm selected for support, and for providing abduction of the lower and upper portions of the arm selected for support with respect to the upper torso for reducing joint stress in the shoulder, and a securing means coupled to the support means for securing the support means to both the patient's arm and upper torso. The support means comprises an inner material having a long member coupled at one end thereof to one end of a short member forming an L-shape, and an outer casing conforming to the L-shape of the inner material for containing the inner material. The inner material comprises a fiberfill material stuffed in a casing. The outer casing comprises a zipper means for providing access to the inner material for removing the inner material from the outer casing. The securing means comprises a first strap means for securing the support means to the patient's upper torso and a second strap means for securing the support means to the patient's arm. The first strap means comprises a waist strap coupled to the long member of the support means for securing to a portion of the patient's waist and a shoulder strap coupled at one end thereof to the unconnected end of the long member and coupled at the other end thereof to the unconnected end of the short member for securing the support means to the patient's shoulder. The shoulder strap is removable. The second strap means comprises an upper arm strap coupled to the short member for securing the upper arm to the support means and a forearm strap coupled to the long member for securing a portion of the patient's forearm to the support means. The forearm strap is removably connected to the long member of the support means for placement at any one location along the long member. In accordance with another embodiment of this invention, an orthopedic pillow support device is disclosed wherein the inner material is comprised of a pre-formed foam material. In accordance with yet another embodiment of this invention, an orthopedic pillow device is disclosed wherein the inner material is comprised of an inflatable air bladder. In accordance with still another embodiment of this invention, a method of providing an orthopedic arm and shoulder support device is disclosed, comprising the steps of providing a portable, reversible, pillow support means for selective attachment to one of the patient's right arm and left arm and the patient's upper torso, the support means comprising an L-shape pillow means for providing support and cushioning for both a lower and upper portion of the arm selected for support, and a securing means coupled to the support means for securing the support means to both the patient's arm and upper torso. The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as ilustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the preferred embodiment of the arm and shoulder support device. FIG. 2 is a perspective view of the support device of FIG. 1 as worn by a person in the upright position. FIG. 3 is bottom view of the support device of FIG. 1 taken along the line 3--3 showing a zipper access on the outer casing. FIG. 4 is a cross sectional view of the long member of the support device of FIG. 1 taken along the line 4--4 showing a fiberfill inner material or a pre-formed foam material. FIG. 5 is a perspective view of the pillow support member of FIG. 1 in another embodiment providing an inflatable air bladder for the inner material. FIG. 6 is a cross sectional view of the long member of the support device of FIG. 5 taken along the line 6--6. FIG. 7 is a perspective view of the support device of FIG. 1 as worn by a person in the recumbent position. FIG. 8 is a perspective view of another embodiment of the forearm strap of the support device of FIG. 1. FIG. 9 is a perspective view of another embodiment of the waist strap of the support device of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a portable, reversible, arm and shoulder, pillow, support device 10, or simply, support device 10, is provided. The support device 10 is comprised of a pillow support 12 and a securing portion which is further comprised of a first strap portion 14, 24 for attaching the pillow support 12 to a patient's upper torso and a second strap portion 30, 34 for attaching the pillow support 12 to the patient's arm. The pillow support 12 is comprised of a long member 20 coupled to a short member 21 forming an L-shape and D-rings 22 coupled to pillow support 12 providing attachments for various straps to the pillow support 12, as described more fully below. The first strap portion 14, 24 is specifically comprised of a shoulder strap 14 and a waist strap 24. The shoulder strap 14 is looped at one end thereof through a D-ring 22. This end of shoulder strap 14 further carries a hook and loop assembly 16, commonly known under the tradename VELCRO, for securing shoulder strap 14 to D-ring 22. The hook and loop assembly 16 further provides a means for adjusting the length of shoulder strap 14 to the patient's preference. Similarly, the opposite end of shoulder strap 14 carries a hook and loop assembly 18 for securing it to the second D-ring 22 and for providing a second means for adjusting the length of shoulder strap 14. Both ends of shoulder strap 14 are provided with hook and loop assemblies 16 and 18 as the means for securing it to the pillow means 12 in order to provide the option of completely removing the shoulder strap 14 from the support device 10. An embodiment with the shoulder strap 14 removed is shown in FIG. 7 and described below. Waist strap 24 is coupled at one end to a back portion of pillow support 12 near the intersection of long member 20 and short member 21. The opposite end of waist strap 24 is similar to either end of shoulder strap 14 wherein it is looped through D-ring 22 and is provided with hook and loop assembly 26 for adjustably securing the support device 10 to the patient's upper torso. The second strap portion 30, 34 is specifically comprised of forearm strap 30 and upper arm strap 34. Forearm strap 30 is comprised of hook and loop assembly 32, whereby a hook strip portion is carried on one side of one end of the strap 30 and a mating loop strip portion is carried on one side of the opposite end of strap 30. Forearm strap 30 is wrapped around long member 20 and the patient's forearm and is secured with the hook and loop assembly 32. Additionally, forearm strap 30 is not attached to pillow support means 12. This allows the patient to secure his forearm to any location along the long member 20 of pillow support 12 depending on the patient's size and preference. Upper arm strap 34 is comprised of a first short strap portion whereby one end is coupled to an inner portion of short member 21 and a second short strap portion whereby one of its ends is coupled to an outer portion of short member 21. The uncoupled ends of the first and second short strap portions carry hook and loop assembly 36 for securing the upper arm to the pillow support 12. It should be understood that support device 10 is reversible and may be used to support and stabilize either a patient's right arm and/or shoulder or a patient's left arm and/or shoulder. Referring to FIG. 2, patient 50 is wearing the support device 10 of FIG. 1 to support and stabilize his left arm 54 and left shoulder 52 while the patient 50 is in the upright position. Specifically, upper arm strap 34 is wrapped around the upper arm 58 to secure it to the short member 21. Forearm strap 30 secures the patient's forearm 56 to the desired location along long member 20. Waist strap 24 is wrapped around the waist and back of patient 50 and tightened and secured through the hook and loop assembly 26 and D-ring 22 (not shown in FIG. 2). Waist strap 24 secures and immobilizes the patient's arm 54 to the patient's upper torso. Shoulder strap 14 is placed over the right shoulder of patient 50 and crosses over to the left portion of his back. Shoulder strap 14 positions and holds forearm 56 at a desired angle relative to the upper arm 58. In this embodiment, forearm 56 is bent at approximately a 90 degree angle with respect to upper arm 58. Taken together, the securing portions 14, 24, 30 and 34 serve to hold, secure and comfortably immobilize the left arm 54 of patient 50, thereby comfortably immobilizing his left shoulder 52 as well. Referring to FIG. 3, the bottom portion outer casing 60 of pillow support 12, comprising zipper 40, is disclosed. The zipper 40 allows for access to and removal of the inner material (not shown in FIG. 3) of pillow support 12 from the outer casing 60 so that the outer casing 60 may be cleaned. After cleaning and drying the outer casing 60, the inner material may be easily reinserted and zipped closed. Referring to FIG. 4, a cross sectional view of a portion of pillow support 12, taken along the 4--4 line of FIG. 1, is provided. The outer casing 60 contains an inner material comprised of fiberfill material 64 contained in a cotton casing 62. Alternatively, the inner material may be comprised of a pre-formed foam material with or without casing 62. Utilizing pre-formed foam material as the inner material provides the benefit of eliminating the need for a casing 62 because, unlike fiberfill material, foam material holds its own shape without external support. Pillow support 12 may be manufactured in a variety of thicknesses resulting in a plurality of support devices 10, each providing a different abduction angle between the patient's arm and upper torso. Offering more than one support device 10 having different abduction angles provides the attending physician or patient the option of selecting the the support device 10 best suited to the patient's conditions and needs. Referring to FIG. 5, an alternative embodiment of the inner material of pillow support 12 is disclosed. It is comprised of an inflatable air balloon 70 and nozzle 72 for inflating and deflating the air balloon 70. The advantage of this embodiment is that pillow support 12 may be inflated to varying degrees determined by the patient's preference or physician's prescription. As the degree of inflation increases, the inflatable air balloon 70 becomes harder or stiffer and the abduction angle formed between the arm and upper torso also increases. In essence, this embodiment allows a single support device 10 to be customized to the patient's needs. Referring to FIG. 6, a cross sectional view of the long member of the inflatable air balloon 70 of FIG. 5 (taken along the 6--6 line) is provided. It is comprised of an outer rubber-type material 80 and is filled with a gas 82, such as air, through nozzle 72. Referring to FIG. 7, patient 100 is shown wearing the support device 10 on the left arm in the recumbent position. In this embodiment, the shoulder strap 14 is typically removed. Referring to FIG. 8, a perspective view of forearm strap 90 is shown. Forearm strap 90 is comprised of strap portion 92 fixedly coupled at one end thereof to buckle 94. A hook portion 96 and loop portion 98 are attached, one next to the other, to the same side of strap portion 92 starting at its second end thereof. When attaching the forearm to the pillow support 12, the patient loops the second end of strap portion 92 of forearm strap 90 through the buckle 92 and folds the end of strap 90 back over the end of buckle 92 so that hook portion 96 may meet and secure to loop portion 98 for securing forearm strap 90 to both the forearm and pillow support 12. Forearm strap 90 may be used in place of forearm strap 30 shown in FIG. 1 and described above. The advantage of forearm strap 90 is that it enables the patient to use his available, uninjured hand to easily and firmly secure forearm strap 90 to the injured arm and pillow support 12. Referring to FIG. 9, a perspective view of waist strap 100 is provided. Waist strap 100 is similar to waist strap 24 shown in FIG. 1 with the following difference: Waist strap 100 is not fixedly coupled at one end to a back portion of pillow support 12 near the intersection of long member 20 and short member 21. Instead, a short strap portion 102 is fixedly coupled at one end thereof to the back portion of pillow support 12 near the intersection of long member 20 and short member 21. The second end of short strap portion 102 is fixedly connected to buckle 104. Waist strap 100 is looped through buckle 104 to secure itself through hook and loop assembly 106 and is therefore removable. As the opposite end of waist strap 100 is also removable, waist strap 100 can attached to pillow support 12 for use on either an injured right arm and/or shoulder or left arm and/or shoulder. While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

An orthopedic pillow device for supporting and immobilizing patient's arm relative to a patient's shoulder is disclosed comprising a portable, L-shaped, reversible, pillow and a plurality of straps for attaching and securing the pillow to both the patient's upper torso and arm. The pillow is selectively attached to one of the patient's right arm and left arm and the patient's upper torso, for providing support and cushioning for both a lower and upper portion of the arm selected for support and for providing abduction of the arm selected for support with respect to the upper torso for reducing shoulder joint stress. The securing means is comprised of a removable shoulder strap, waist strap, forearm strap and upper arm strap.

BACKGROUND OF THE INVENTION [0001] (1) Field of the Invention [0002] This invention relates to shaft seals, and more particularly to turbine engine shaft seals. [0003] (2) Description of the Related Art [0004] In turbomachinery applications, it is often necessary to provide a seal between a rotating shaft and a housing element. At the seal, the shaft typically has symmetry around a central axis (e.g., the shaft has a cylindrical surface area). The shaft axis is normally coincident with the axis of rotation and with an axis of the housing in which the seal is mounted. However, vibration may induce small local oscillatory excursions of the axis of rotation. Brush and labyrinth seals may have sufficient compliance in their respective bristle packs and labyrinth teeth to accommodate relatively minor excursions. To accommodate greater excursions, there may be a non-rigid mounting of the seal element to the housing. This mounting permits excursions of the shaft axis to radially shift the seal relative to the housing to avoid damage to the seal. BRIEF SUMMARY OF THE INVENTION [0005] A turbine engine has a rotor shaft rotatably carried within a non-rotating support structure. A seal is carried by the support structure circumscribing the shaft and having a flexible sealing element for sealing with the shaft. A chamber is located between the seal and support structure. A fluid is carried within the chamber and damps radial excursion of a seal axis from a support structure axis. The seal may be a full annulus or may be segmented. The fluid may be contained within one or more elastomeric bladders. [0006] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS [0007] [0007]FIG. 1 is a longitudinal semi-schematic sectional view of a turbine engine. [0008] [0008]FIG. 2 is a partial semi-schematic longitudinal sectional view of a seal system of the engine of FIG. 1. [0009] [0009]FIG. 3 is a partial semi-schematic transverse sectional view of the seal system of FIG. 2, taken along line 3 - 3 . [0010] [0010]FIG. 4 is a partial semi-schematic longitudinal sectional view of an alternate seal system. [0011] [0011]FIG. 5 is a partial semi-schematic transverse sectional view of an alternate seal system. [0012] Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION [0013] [0013]FIG. 1 shows a turbine engine 20 having a housing case 22 containing concentric high and low pressure rotor shafts 24 and 25 . The shafts are mounted within the case for rotation about an axis 500 which is normally coincident with central longitudinal axes of the housing and shafts. The high pressure rotor shaft 24 is driven by the blades of a high pressure turbine section 26 to in turn drive the blades of a high pressure compressor 27 . The low pressure rotor shaft 25 is driven by the blades of a low pressure turbine section 28 to in turn drive the blades of a low pressure compressor section 29 and a fan 30 . [0014] The rotor shafts are supported relative to the case by a number of bearing systems. The rotor shafts may be sealed relative to the case by sealing systems 40 which may include brush sealing elements, labyrinth sealing elements, or the like. [0015] [0015]FIG. 2 shows further details of an exemplary sealing system 40 . The exemplary system includes a brush seal 50 having a bristle pack 52 secured in a seal body comprising a pair of backing plates 54 and 56 . The plates 54 and 56 are respectively designated as the side plate and the back plate and sandwich the bristle pack on respective high and low pressure sides thereof. In the exemplary embodiment, the bristle roots are secured between the plates with bristle tips extending inward therefrom to contact the shaft outer surface 60 . Bristle and plate materials are typically various metal alloys such as nickel- or cobalt-based superalloys and the plates and bristle roots may thus be secured by welding. Additional shorter bristles may intervene between the sealing bristles contacting the shaft and the backplate. The tips of these bristles may be closer to the rotor than is the inboard surface of the backplate. Such an arrangement provides additional support to the sealing bristles during true running operation while limiting the chance of damage during a rotor excursion. [0016] The seal 50 is contained within an annular seal backing/mounting ring 62 . The ring 62 includes an annular sleeve portion 64 having interior and exterior surfaces 66 and 68 . On the low pressure side, a short flange 70 extends radially inward from the surface 66 . The seal is accommodated within the ring such that an exterior rim surface 72 of the seal contacts the interior surface 66 while a downstream radial surface of the plate 56 contacts an upstream radial surface of the flange 70 . A retaining ring 74 is captured in a groove in the surface 66 so that a downstream surface of the ring 74 contacts an upstream surface of the plate 56 to sandwich the seal 50 between the plate 74 and flange 70 to firmly retain the seal relative to the mounting ring. [0017] The mounting ring 62 is accommodated within a compartment in the case defined by respective downstream and upstream surfaces 80 and 82 of upstream and downstream walls 81 and 83 and an interior surface 84 of an annular wall 85 . Upstream and downstream rims of the sleeve 64 carry o-rings 90 for sealing with the surfaces 80 and 82 . The mounting ring 62 includes a pair of upstream and downstream seal rings 94 and 96 extending radially outward from the exterior surface 68 . Exemplary seal rings may be similarly formed to split piston rings. They may be formed by a casting and machining process. Hoop stress in the seal rings may allow them to maintain engagement with the mounting ring while freely sliding radially within the channels 100 and 102 . Fluid pressure may allow the seal rings to seat axially against radial surfaces of the channels. [0018] Exterior annular rim portions of the rings 94 , 96 are captured within radial channels 100 and 102 in the surface 84 . The channel bases are of sufficiently greater diameter than the sealing ring rims to permit the sealing rings (and thus the mounting ring) a desired amount of radial float relative to the case. The sealing rings and portions of the sleeve 64 and wall 85 between the rings bound a first chamber 120 containing a fluid 122 . Exemplary fluids are oils, water and air. Advantageously in a turbine engine application, the fluid is useful in an operational range of 150° C. to 550° C. (e.g., is non-flammable and does not undergo a phase change or decompose). [0019] The fluid 122 may be introduced to the chamber 120 through a port 124 in the wall 85 . A fluid source may comprise a reservoir 130 such as a sump tank or pressure vessel. To deliver the fluid from the reservoir, a pump 132 is connected to the reservoir via a conduit 134 . The pump is connected to the port 124 via a conduit 136 in which a pressure regulator 138 is positioned. The pressure regulator is in turn coupled to the reservoir via a conduit 140 for returning excess fluid to the reservoir. [0020] In operation, there may be leakage of the fluid around the rings 94 and 96 into chambers 144 and 146 between the sleeve 64 and wall 85 respectively upstream and downstream of the rings 94 and 96 . Ports 150 and 152 are provided in the wall 85 on respective upstream and downstream sides of the rings 94 and 96 to permit a return of leaked fluid from the chambers 144 and 146 to the reservoir via a return conduit system 160 . [0021] [0021]FIG. 3 shows exemplary segmenting of the case and seal system. The exemplary case is longitudinally split into two 180° sections along a planar split interface 520 . To maintain the integrity of the ring 62 , its interfaces are provided with shiplap/tongue & groove connections. The seal 50 is split into nominal 90° segments along four planar interfaces 524 . The interfaces 524 are at an off-radial angle so as to be locally parallel to the bristles. The mounting ring 62 is similarly split or may be split in two, similar to the case. [0022] In operation, a radial excursion of the shaft axis relative to the case axis will apply a net force to the bristles. The force is transmitted to the rigid portions of the seal (e.g., the plates and fixed outboard bristle ends. In doing this, the bristles may flex. Advantageously the pump and regulator maintain sufficient fluid pressure that, given fluid viscosity, density, and other properties, permit the fluid to damp radial excursion of the seal induced by the force. It may be possible for the engine control system (not shown) to regulate pressure based upon engine operating conditions to provide a desired degree of damping. [0023] [0023]FIG. 4 shows an alternate sealing system 200 . Elements in common with the exemplary sealing system 40 are referenced with like numerals. In this embodiment, the seal 50 is similarly held within a mounting ring 210 . The mounting ring 210 is captured within a channel 212 formed in a housing wall 214 . A flexible annular bladder 216 (e.g., formed of a suitable elastomer) is positioned between an exterior surface 218 of the mounting ring 210 and a base surface 220 of the channel 212 . The bladder contains a fluid 224 . The bladder is coupled via one or more ports 226 in the housing to supply lines 228 from a pump 230 delivering the fluid from a reservoir 232 . A regulator 234 is positioned in the supply lines and has a return line 238 for returning fluid to the reservoir 232 . [0024] In operation, the sealing system 200 could be controlled in a similar fashion to the system 40 . For an excursion of the seal, the bladder will be locally compressed at one diametric location and locally expanded at the opposite location. Thus the elasticity and other properties of the bladder are relevant to the degree of resistance offered to seal excursions. Relative to the system 40 , this elasticity may provide a greater degree of resistance (e.g. a spring constant) to excursion for a given degree of damping. Relative to the system 40 , the system 200 may be particularly useful with compressible fluids. Automated control of fluid pressure in the system 200 may provide a high degree of control of seal support. In such an automated system, speed and vibration (e.g., actual vibration levels measured via proximity probes) parameters could be measured and further control inputs could be provided indicating other conditions of operation (e.g., whether the engine was accelerating or decelerating). At startup conditions, a very low pressure could be applied to permit the seal to accommodate the rotor excursions (known as “critical vibration”) typical at startup. In stable running conditions, higher pressure could be maintained to keep the seal centered. This may be desirable to prevent high cycle vibration (HCV) from affecting the seal. At lower pressures, the seal may be more prone to HCV. It may be possible to use the engine's compressor as a source of high pressure fluid. [0025] [0025]FIG. 5 shows an alternate sealing system 300 in which the bladder is itself segmented into four segments or smaller bladders 310 positioned end-to-end circumscribing the shaft. Each exemplary bladder 310 extends around somewhat less than 90° of the shaft. The bladder segments are positioned approximately coincident with segments of the seal 50 and its mounting ring 312 . Each bladder segment is connected via a case port 314 to a common header supply lines and associated equipment as in the embodiment of FIG. 3. Operation of the system 300 may be generally similar to that of the system 200 . The use of separate bladder segments may tend to further increase the effective spring constant for a given fluid type and pressure, bladder material, and the like. Additionally, there exists a possibility of fully or partially independent control over the pressure in the bladder segments giving rise to the possibility of an active positioning of the seal under automated control. [0026] One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, environmental considerations may influence parameters of seal construction. Similar seals could be used in non-rotating (e.g., static) brush seal applications. In such applications, wear and heat generation may be of less concern than compacting the bristle pack. Such compacting can cause flaring of the bristle tips (brooming) and/or cause the bristles to be permanently deformed to increase the bristle pack inner diameter. Additional features are possible such as a seal anti-rotation features (e.g., radial pins or tabs mounted to the seal and riding in slots in the case). Accordingly, other embodiments are within the scope of the following claims.

A turbine engine has a rotor shaft rotatably carried within a non-rotating support structure. A seal is carried by the support structure circumscribing the shaft and having a flexible sealing element for sealing with the shaft. A chamber is located between the seal and support structure. A fluid is carried within the chamber and damps radial excursion of a seal axis from a support structure axis. The seal may be a full annulus or may be segmented. The fluid may be contained within one or more elastomeric bladders.

BACKGROUND OF THE INVENTION A major objective of the present invention is to improve on the tool disclosed in U.S. Pat. No. 4,373,380, Mayo. In accordance with the present invention, the utility of the patented tool has been greatly expanded, while its structure has been considerably simplified and its manufacturing cost reduced. These important improvement features result mainly from the fact that the outside diameter of the improved tool has been substantially reduced in comparison to the outside diameter of the patented tool. As a result of this diameter reduction, the improved tool is not limited in its usage to testing internal sealing surfaces of relatively large diameter well head housings. The improved tool can be used to test the integrity of relatively smaller diameter well casings and other sleeve members. The casing, casing hanger and connecting joints immediately below the blow-out preventer (BOP) or well head can fail during well drilling operations. Such failures are responsible for a number of very costly blow-outs. The U.S. Minerals Management Service does not presently require testing of well components below the casing hanger, and heretofore this area of the well, as a practical matter, could not be tested. The present invention satisfies a need for a practical and economical test tool for the zone of a well below the casing hanger. A further objective of the invention is to provide a multipurpose tool which can be used to isolate members of the well head, BOP and hanger assembly for testing. In accordance with this invention, the improved tool has four main functions: 1. As an isolation tool, the unit can be run in 183/4", 163/4" and 135/8" BOPs to determine leakage in these components. 2. The tool can test an intact sub-sea well head housing which has been used or repaired and will provide a graphic chart of the test as a permanent record in the manner disclosed in U.S. Pat. No. 4,373,380. This enables an operator to make a decision on scrapping or reconditioning a used well head housing so that the useful life of the same can be extended. 3. The tool according to the present invention can replace cup-type testers. Its seals are much more durable and will far outlast cup-type seals which are subject to damage as they are pulled from the well. 4. The improved tool serves as a key seat indicator tool. The relatively thin lips of metal containment rings for elastic seal elements indicate key seat wear present in well casings by bulging outwardly into key seat recesses under influence of fluid pressure. An operator observing this condition can reposition the drilling pipe or mobile rig before key seat wear in one location has become too great to tolerate. Other features and advantages of the invention will become apparent to those skilled in the art during the course of the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B, when matched on match lines 1A and 1B, form a central vertical longitudinal section through a test and isolation tool for wells, partly in elevation. DETAILED DESCRIPTION Referring to the drawings in detail wherein like numerals designate like parts, a test and isolation tool for wells according to the present invention comprises a mandrel 10 which is cylindrical and tubular throughout most of its length. At its upper end, the mandrel includes an enlarged diameter head 11 which is internally screw-threaded as at 12 to receive thereon a Baker locked PUP 13. At its lower end, the mandrel 10 is externally threaded as shown at 14 to receive an internally threaded seal support 15, on which is threadedly mounted a deburring ring 16 secured in place by an anti-back-off screw 17 anchored in the seal support 15. A threaded protector/guide 18 is also carried on the forward end portion of the seal support 15, as shown. The seal support 15 includes a shoulder 19 which is locked by screws 20 to the lower end face of mandrel 10. The seal support 15 is optionally internally threaded at its lower end, as indicated at 21, to receive a closure plug, when such plug is necessary. Mounted on and surrounding the mandrel 10 between its enlarged head 11 and the seal support 15 are separate oppositely axially movable seal energizer rings 22 and 23. A space 24 between the two energizing rings 22 and 23 defining two opposing piston faces 25 is in communication with a radial port 26 formed through the wall of mandrel 10. This mandrel port 26 registers with a radial port 27 formed in a two-piece or one-piece dart 28 which extends upwardly to and beyond the PUP 13. On opposite sides of the ports 26 and 27, the seal energizing rings 22 and 23 and mandrel 10 are sealed by "POLYPAK" seals 29. Similarly, the bore of mandrel 10 and the dart 28 therein are sealed by additional "POLYPAK" seals 30. Another such seal 31, FIG. 1B, seals the lower end of the mandrel with the lower seal support 15. When inclined faces 32 and 32' of the dart 28 and mandrel 10 are solidly engaged, the radial ports 26 and 27 are disposed in registration. The seal energizing ring 22 includes an integral lower skirt portion 33 which overlaps the upper portion of the relatively movable seal energizing ring 23, FIG. 1A. These overlapping ring parts are sealed by another "POLYPAK" seal 34. Upper and lower seal assemblies 35 and 36 of the same type shown in U.S. Pat. No. 4,373,380 surround the upper portion of mandrel 10 and the seal support 15. The metal seal containment rings 37 of the two seal assemblies enter annular seats 38 and 39 formed in the seal energizer rings 22 and 23, respectively. The other metal containment rings 40 of seal assemblies 35 and 36 surround the mandrel 10 and seal support 15 and have their ends engaging a guide ring 41 on the mandrel 10 and an annular shoulder 42 on the seal support 15, respectively. Elastic seal elements 43 of the two seal assemblies are secured to the containment rings 37 and 40 and function therewith in the manner described in U.S. Pat. No. 4,373,380. A somewhat inclined test fluid port 44 is formed through the upper end portion of mandrel 10 and intersects an annular cylindrical chamber 45 within which the two interfitting seal energizing rings 22 and 23 operate like opposing pistons at proper times. Diagonal test fluid ports 46 lead from the chamber 45 through the exterior faces of rings 22 and 23 to deliver pressurized test fluid to the region between the two seal assemblies 35 and 36. An important feature of the construction of the tool contributing to its small outside diameter resides in the utilization of the outer surface of the mandrel 10 as one wall of the cylinder chamber 45 while the interior surface of the skirt portion 33 forms the other wall of the cylinder chamber. The interfitting parts of seal energizing rings 22 and 23 function as opposing pistons which move axially apart and together within the chamber 45 as the elastic seal elements 43 are energized and relaxed. Pressurized seal energizing fluid is delivered through the bore 47 of dart 28 and then through registering ports 27 and 26 to the space 24 between the opposing piston faces 25 of seal activating rings 22 and 23. The pressurized fluid acts simultaneously on the piston faces 25 to force the rings 22 and 23 apart axially, thereby compressing and energizing the elastic seals 43 so that the latter will effectively seal critical surfaces of the bore of a surrounding housing, casing or the like shown at 48. After the seals 43 are fully energized, as described in U.S. Pat. No. 4,373,380, test fluid at a required test pressure is introduced through the port 44 and passes through ports 46 to the exterior of the tool between the seal assemblies 35 and 36 and the critical surfaces of the element 48 which are being tested. The pressure test procedure and results being fully described in U.S. Pat. No. 4,373,380 need not be repeated herein in greater detail to enable a full understanding of the invention. An optional feature not specifically shown in the prior patent is the inclusion of pressure gages on the two lines 92 and 93 in the patent. These gages, when employed, are connected by two hoses with the lines 85 and 86 near the two separator units 87 in the prior patent. It can be seen that the comparative simplicity and compactness of the test and isolation tool according to the present invention allows its use in well casings, pipes and the like which heretofore could not be tested because of the larger diameter of the prior art tool. In accordance with a further important capability of the improved tool, the test fluid port 44 and communicating ports 46 could be eliminated entirely or, if present, need not be used to deliver test fluid. Instead, the pressurized test fluid can be delivered through a radial port 49 in the surrounding tubular member 48 into the area between the seal assemblies 35 and 36. With this arrangement, the test tool itself may have its seals tested on a job site prior to running the tool into a well. It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.

A test and isolation tool for wells of expanded utility and reduced manufacturing cost is disclosed. The outside diameter of the tool is significantly reduced and its overall construction is simplified by total elimination of a previously-employed annular piston. In lieu thereof, the outer surface of a mandrel forms one wall of a cylinder chamber for interfitting axially displaceable seal energizing rings which operate as pistons. The interior surface of a skirt portion of one seal energizing ring forms the other wall of the cylinder chamber for the two rings.

FIELD OF THE INVENTION The invention relates to a radiating structure of power converters, especially to a radiating structure in which the joining of a heat conductor plate and the housing is specially arranged in a decent position so that heat can be quickly and uniformly transfered to the fins formed on the housing and then taken away by air and ventilation channels are formed around the heat conductor plate to allow fresh air to get into the housing for cooling the heat conductor plate. DESCRIPTION OF A PRIOR ART Along with the quick development of computers, the demand of peripheral devices also increases fast. Some devices, such as disk drivers, interface cards, receptacles, and power converters, are built in a computer. As to a power converter, it functions as a regulator to adapt alternating currents to a computer that needs direct currents. Such apparatuses are vital to a portable computer. Besides, in America and Europe, people like to enjoy their leisured life on vacations or holiday. Most of their leisured activities are done outdoors. However, there is seldom electricity supply available in camping areas, The only energy source available is the direct currents of a car battery. Hence, electrical appliances designed to use alternating currents will have difficulties in an outdoor use. The power converter according to the invention is intended to alter a direct current into an alternating current. A conventional structure of D.C./A.C. power converters is shown in FIG. 1, which comprises a housing 100, an electrical circuit board assembly 102 having a power conversion function and held between two guide slots 104, a heat conductor plate 106 soldered on the circuit board 102 and fixed to the side wall of the housing by screws 108 in such a way that the heat conductor plate 106 lies flat on the housing to dissipate heat through the housing. However, the heat dissipation method of a conventional structure has the deficiency that because the heat conductor plate 106 abuts against one side wall of the housing 100 one side wall 100a is always higher than the other side wall 100b in temperature although a cooling fan is used to circulate the air in the compartment 100c. As a result, uneven heat conduction prevails, leading to a poor dissipation effect. Therefore, it is desirable to have an improved structure in which the foregoing drawbacks existing in a conventional radiating structure have been removed. SUMMARY OF THE INVENTION The object of the present invention is to provide a radiating structure of a power converter that dissipates heat from the top of the housing where a heat conductor plate joins with the housing so that heat can be quickly and uniformly released into surroundings and the heat dissipation effect of which radiating structure is further reinforced by use of cool air streams drawn in by a fan and urged to flow through channels formed between the heat conductor plate and the housing. To accomplish the above goal, the radiating structure of a power converter according to the invention comprises a housing, a front cover, a rear cover, a printed circuit board assembly, and a base plate. The housing has fins provided on the outer surface thereof that has the effect of an enlarged heat dissipation area. The housing further has a positioning groove and screw holes disposed in the top inner surface thereof, two opposed guide slots respectively integrally formed on the inner surface of two side walls, and a plurality of slit threaded holes formed at the corners and ends of the side walls of the housing. The front and rear covers are respectively attached to the front and rear ends of the housing by screws tightened on the slit threaded holes; the front cover being provided with receptacles and the rear cover having a power cord, fuse, and a fan. The printed circuit board assembly is held between two guide slots and includes a perpendicularly bent heat conductor plate soldered on the board thereof and provided with a raised block that cooperates with the positioning groove and fastening screws to make the top of the heat conductor plate lie flat on the inner wall surfaces of the housing so that heat can be evenly dissipated through the housing and be driven away by a fan that takes in cool air from the outside and makes it pass through the ventilation channels formed between the walls of the housing and the heat conductor plate. BRIEF DESCRIPTION OF THE DRAWINGS The structure, applied principles, features, and advantages of the invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings wherein: FIG. 1 is a cross-sectional view showing a prior art radiating structure of power converter; FIG. 2 is an exploded view showing the radiating structure according to the invention. FIG. 2A is a partial perspective view showing the fan structure. FIG. 3 is a cross-sectional view illustrating the radiating structure of the invention. FIG. 4 is a schematic cross-sectional view of a housing according to the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIG. 1, there is shown a prior art power converter of which the radiating structure conducts heat transfer by means of single sidewise contact. Hence its surface heat dissipation is not even and the cooling efficiency is poor. FIG. 2 is an exploded view showing the structure of a power converter of the invention. The power converter comprises a housing 1, a front cover 2, a rear cover 3, a printed circuit board assembly 4, and a base plate 5. As shown in FIG. 4, the housing 1 of the converter has a positioning groove 11 disposed in the inner top surface of the housing 1 and having a plurality of threaded holes 12 formed therein, two opposed guide slots 13 arranged near the end of the side walls of the housing 1, and slit threaded holes 14 and 15 formed at the corners of the walls of the housing and the ends of the side walls. The front cover 2 includes receptacles 21 and screw holes 22 near the four corners thereof, by means of screws 23 passing through which holes 22 and the slit threaded holes 14 the front cover 2 can be fixed onto the housing 1. The rear cover 3 is provided with a power cord 31, fuse 32, exhaust fan 33, screw holes 34 formed at four corners thereof, and fastening screws 35 that attach the rear cover 3 to the housing 1 on the slit threaded holes 14 and 15. The board width of the printed circuit board assembly 4 corresponds to the distance between two guide slots 13 so that two slots 13 can hold the printed circuit board assembly 14, with a right-angled heat conductor plate 41 soldered on the board. The heat conductor plate 41 includes a raised block 42 formed on the central portion thereof and provided with threaded holes 43. The base plate 5 is a flat sheet with screw holes 51 disposed at four corners, through which holes 51 the base plate 5 is fixedly secured to the bottom of the housing 1. In assembly, two opposed board edges of the printed circuit board assembly 4 are inserted into opposed guide slots 13 in such a way that the raised block 42 of the heat conductor plate 41 engages with the positioning groove 11 with screws 6 passing through threaded holes 12 and 43 to join the heat conductor plate 41 and the housing 1. As a result, the heat conductor plate 41 and the housing 1 are kept in a state of close contact with each other. From the above description, it is evident that the heat conductor plate 41 of the invention can dissipate heat through the surface contact between the plate and the housing, much better than the single side contact method used in a prior art converter. Furthermore, FIG. 3 shows a cross section of the converter assembly according to the invention. As can be seen from it, in the radiating structure of the power converter of the invention, the heat conductor plate 41 abuts against the housing 1 at the top so that the space between the walls of housing 1 and the heat conductor plate 41 forms ventilation channels x and y through which the cool air inhaled from the outside by a fan 33 on the rear cover 3 as seen in FIG. 2A flows and takes away heat to enhance the cooling effect, resulting in superior dissipation performance. As a consequence, the radiating structure of the power converter according to the invention can evenly transfer heat to surroundings through an improvement made on the joining area between the heat conductor plate and the housing. Additionally, the space around the heat conductor plate becomes a passage for cool air flows. Such cooling means are a revolutionary design and can achieve the maximum dissipation effect.

A printed circuit board and heat conductor plate assembly is secured within an housing that includes a front cover, a rear cover and a base plate, whereby heat is dissipated from the assembly through exterior fins of the housing by a fan which directs cool air between the walls of the housing and the heat conductor plate.

BACKGROUND OF THE INVENTION 1. Field of the invention This invention relates to an optical confocal scanning microscope. 2. Description of the Related Art U.K. Patent Publication No. 2 184 321A discloses a confocal scanning optical microscope which is especially for the study of fluorescent or reflecting specimens. This instrument depends upon the focussing of light upon a single spot scanned over the specimen, which illuminated spot, after de-scanning, is imaged on a confocal aperture in front of a detector. In the case where an image is to be formed of fluorescence from a specimen, the wavelength of the light directed on to the specimen is selected in such a way as to excite fluorescence. The emitted light is separated from the exciting light by a suitable beam splitter and is passed through wavelength-selective filters in such a way that the detector responds only to the light emitted by fluorescence. Instruments based on this design are commercially available. They contain a provision for subdividing the emitted light into beams of different wavelength ranges by a suitable beam splitter and filters. After this division, two dyes can be employed which emit different colours of fluorescence which can be distinguished at two detectors. Alternatively, a reflectance image can be obtained at the same time as a fluorescence image by the use of suitable beam-splitters, in accordance with accepted optical practice. The prior art instruments work satisfactorily but all confocal scanning microscopes which rely on the use of a single scanning spot suffer from the defect that all the spectral selectivity of the system lies in the separation of the emitted or reflected beam into fractions of different wavelength. If there is considerable overlap between the fluorescent emission spectra of two dyes, they cannot be distinguished. For example, Bacallao et al comment in the Handbook of Confocal Microscopy, Plenum Press, 1990, that the commonly-used dyes fluorescein and rhodamine cannot be separated effectively in a system of this type. In order to achieve acceptable separation, it is necessary to vary the wavelength of excitation. This can be done by changing from one type of laser light to another, of spectrally different properties. First an image is obtained by operating the system with one type of excitation, and then a second image is obtained with a different type of exciting beam. This operation is slow and cumbersome. Awamura, Ode and Yonezawa have described a microscope in which red, green and blue laser beams are scanned independently over the specimen, and the reflected beams are separated by dichroic filters and each executes a scanning motion over one of three separate linear CCD detector arrays. The description was published in the Proceedings of SPIE, The International Society for Optical Engineering (1987) Volume 765 pp 53-60. In principle, the system of Awamura et al might be used as a fluorescence microscope. It would then allow more than one type of dye to be excited in rapid succession during each line scan. However, in the case of two dyes with identical emission spectra, or a single ratiometric dye where the emission spectrum was to be monitored in a single waveband, the system of Awamura et al offers no advantage over that of White (U.K. Patent Application No. 2 184 321A), since neither system is capable of separating the two emission signals. SUMMARY OF THE INVENTION According to the present invention, there is provided a confocal scanning optical microscope comprising: an optical scanning system; means for simultaneously generating two or more input beams of optionally different spectral composition and of differing orientations such that after passage through the scanning system a specimen under test is scanned with two or more distinct and separate elemental areas of illumination; and two or more detectors respectively for receiving two or more output beams after de-scanning by the scanning means, each detector receiving an output beam substantially restricted to output light derived from one of the illuminated elemental areas. The invention allows for two or more microscope channels having different excitation wavebands but identical emission wavebands, in order to make possible excitation ratio image measurements according to accepted practice. The invention also allows for two or more microscope channels having identical excitation wavebands but different emission wavebands, in order to make possible emission ratio image measurements according to accepted practice. The present invention is thus applicable to many kinds of scanning optical microscopes. It provides a means by which two or more spectrally distinct exciting spots or bars can be scanned together over the specimen during each sweep of the scanning system. The emission from each spot is passed individually and separately to a stationary confocal aperture leading to a detector, there being at least one aperture and detector for each spot. The emitted beam from each spot, due to specimen fluorescence or reflection, may be filtered spectrally or subdivided between detectors in accordance with established practice, or may be passed unselectively to the detectors. It is thus possible to obtain, within a single scanning cycle, two or more complete images, each of which may differ in both excitation and emission waveband from the other images. The invention may be considered as "a multiplexed optical system" because it involves two or more sets of independent but near-parallel beam paths passing through the same scanning system and objective lens, the optical paths being multiplexed in the literal sense of being folded together. BRIEF DESCRIPTION OF THE DRAWINGS Further features and advantages of the invention will be apparent from the following description of embodiments, making reference to the accompanying drawings, in which FIG. 1 is a schematic diagram of a confocal scanning microscope incorporating the multiplexed optical system of the present invention; FIG. 2 is a schematic diagram showing an alternative and preferred optical arrangement for the upper part of FIG. 1; and FIG. 3 is a schematic diagram showing an optical means by which several beams of different spectral properties may be obtained from a single (e.g. a multiline) laser, for use in the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, the present invention provides an optical assembly which allows a number of independent optical channels to be used simultaneously for excitation in a laser confocal scanning microscope with an extended emission beam path, but is not restricted in application to this kind of microscope. The invention can be applied to confocal microscopes in which a bar or slit of light is scanned over the specimen as well as to those in which a single spot is scanned. In FIG. 1, to simplify the diagram, only two independent light paths are shown, but there is no restriction on number in practice. Light from two lasers, L1 and L2, with different spectral qualities, is directed on to a beam splitter BS1. The two beams are at a slight angle to each other, which angle is exaggerated in the diagram for the sake of clarity. The two beams are reflected into a scanning system as shown, which produces an angular scan of both beams simultaneously. The angular separation of the beams is maintained throughout the scan, and results, after passage through suitable microscope optics, typically an eyepiece E and an objective O, in the formation of two distinct moving spots of light S1 and S2 on the specimen. Light is emitted from the specimen at S1 because of reflection or fluorescence and a portion of this emitted light passes back through the optical system, is descanned, i.e. reconverted into a stationary beam by the scanning system, passes through the beam splitter BS1 and falls on a confocal aperture Al leading to a detector D1. Light from S2 passes through the optical system along a similar but distinct path and falls upon detector D2. The preferred angular separation is the smallest possible consistent with a satisfactory separation of the optical channels. To allow image registration, the small difference in time between the scanning of a given point in the specimen by the spots corresponding to S1 and S2 may be compensated by suitable conventional electronic means, for example by image processing software. It is not essential to the functioning of the system that the two or more spots should lie upon the same scan line. In the preferred embodiment of FIG. 2, the scanning device and microscope are not shown in the figure, but should be taken to be the same as in FIG. 1. Beams from lasers L1 and L2 again pass at a small angle on to the beam splitter BS1. The returning beams, after passing through beam splitter BS1, pass to a second beam splitter BS2, which has dichromatic properties, so that most of the light in one of the beams, B2, passes through to confocal aperture A1 and thus to detector D1, while the other beam B1 is preferentially reflected to A2 and D2. This modification is preferred as it allows the use of the second beam splitter BS2 to achieve a selection of emission wavelengths, and also may be implemented by only slight modification of existing instruments. The separation of the emitted beams by wavelength may be improved by the addition of wavelength-selective filters F1 and F2. The aiming of the emission beams, each on to the appropriate aperture A1 or A2, may conveniently be achieved by the use of mirrors (not shown) interposed between BS2 and the detectors D1 or D2. Additional mirrors and dichromatic reflectors may provide convenient means of achieving an appropriate angle between the input beams L1 and L2. For example, FIG. 3 illustrates one of many possible means by which light from a single multiline laser L may be separated into beams of different spectral composition and angle. In this case, a parallel-sided block B of glass or other transparent material is used to produce a small lateral separation of the beams according to wavelength. The angle between the beams is then adjusted by passing them through a prism P, where they undergo different angular deviations because of the dispersing power of the prism. By appropriate orientation of the prism, parallel beams, each corresponding to a single wavelength, are generated, which converge towards the beam splitter BS1. The angle of convergence is determined by the angle of the prism and its refractive index and dispersive power. In the diagram, the solid line S indicates a beam at a shorter wavelength, which is more strongly refracted than the beam, shown by the dashed lines D, corresponding to light of a longer wavelength. Various modifications of the above-described and illustrated arrangements are possible within the scope of the invention hereinbefore defined.

A confocal scanning optical microscope in which a specimen under test is simultaneously scanned with two distinct spots or slits of illumination and two output beams emitted from the specimen due to reflection or fluorescence are descanned and passed to separate stationary confocal apertures and detectors.

TECHNICAL FIELD This invention relates generally to portable electronic devices, and more particularly to a portable electronic device having wireless communications features. BACKGROUND OF THE INVENTION Portable electronic devices, such as laptop and notebook computers, dataform readers, barcode readers, portable data terminals, work slates, pen computers, portable electrical testing devices, and touch screen displays typically require the ability to communicate data with an external device. Due to the portability of these devices, they are typically remotely powered by a battery pack, enabling their use without connection to power supply or communication lines. Typically, such devices are equipped with one or more forms of memory and an I/O port, enabling intermittent hook-up to a data communications network for transmitting and receiving information therebetween. Additionally, an AC power supply is frequently provided via a power supply port for intermittently connecting the device to a separate power supply during operation, or for recharging batteries contained therein. One technique for transferring data and/or verbally communicating with an electronic device such as a computer system involves connecting the device to a public switched telephone network (PSTN) via a telephone modem. For example, a telephone modem, short for modulator/demodulator, is often used on a computer and consists of a communications device that enables the computer to transmit information over a standard telephone line. An RJ-11 jack and connector enable coupling of the computer and modem with a telephone line. The modem converts the digitally formatted information of a computer into an analog signal that is capable of being carried over the telephone line to another computer. The receiving computer has a modem that transfers the analog signal transmitted over the telephone line back into a digital signal usable by the receiving computer. Typically, the modem modulates a computer's digital signal onto a continuous carrier frequency over the telephone line. When receiving, the modem demodulates the information from the carrier, transferring it into digital form for use by the computer. However, it is sometimes inconvenient to utilize a telephone line for coupling together computer systems. In some cases, a hard wire telephone line is not available to a user for use with the computer. For other cases, the computer or electronic device is required to communicate frequently and intermittently with another computer, which would require frequent coupling and decoupling of a telephone line with a jack on the computer to enable portable movement of the computer and subsequent connection after each cycle of use. According to another way, some portable electronic devices have a dedicated antenna, a cellular radio telephone, and a cellular radio modem configured to enable communication between the device and an external communication device. For example, portable cellular telephones have self-contained antennas for enabling communication with other similar devices via a cellular network. Additionally, laptop and notebook computers have been configured to couple with a cellular telephone via a PCMCIA slot and a connector to enable transmission of data via a cellular modem between the notebook computer and another communications device. However, cellular telephone airtime can be very expensive. Therefore, there is a need for a way to reduce cellular airtime when sending and receiving data in order to reduce cellular airtime charges. One attempt to reduce cellular airtime costs, or charges, when sending data has been to implement packet data service for first and second generation cellular systems such as the Cellular Digital Packet Data (CDPD) standard. CDPD provides mobile packet data connectivity via an AMPS channel on a shared basis. Since users are charged on a packet-by-packet basis, CDPD typically transfers data at reduced cost. CDPD coexists with a conventional voice-only cellular system such as AMPS, but it capitalizes on the unused air time which occurs between successive radio channel assignments by the Mobile Switching Center (MSC). However, many applications still require that a considerable amount of data and/or voice communication be implemented. For example, warehouse personnel performing inventory analysis and/or processing orders in a warehouse with portable computing devices having wireless communications capabilities still must transfer a large amount of data, incurring substantial cellular connection charges. Therefore, there is a need to reduce commercial cellular connection charges when performing data/voice transmissions within a defined geographic location such as a warehouse or factory. The present invention relates to an improved portable electronic device having wireless communications features that minimize use of commercial cellular networks when transmitting data/voice between the device and another device. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are described below with reference to the following accompanying drawings. FIG. 1 is a perspective view of a notebook computer having wireless communications features and switching circuitry for selectively configuring the wireless communications features between local and wide area communications networks; FIG. 2 is a schematic block diagram illustrating a portable electronic communications device having a proximity detection device and switching circuitry for selectively configuring wireless communications between local and wide area networks; FIG. 3 is a schematic block diagram illustrating in further detail one technique using received radio frequency (RF) power detection for implementing the proximity detection device of FIG. 2; FIG. 4 is a schematic block diagram illustrating in further detail another technique using data stream error detection of received radio frequency (RF) signals for implementing the proximity detection device of FIG. 2; and FIG. 5 is a schematic block diagram illustrating in further detail yet another technique using a pair of radio frequency (RF) ground wires for implementing the proximity detection device of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws "to promote the progress of science and useful arts" (Article 1, Section 8). According to one aspect, this invention comprises a portable electronic communications device, comprising a radio frequency modem, wireless communications circuitry, and an antenna operable to communicate over a wireless communications link with one of a local area network and a wide area network; and a proximity detection device operable to detect proximity of the device with the local area network, the wireless communications circuitry responsive to detection of the device within suitable signal communication proximity with the local area network to couple the communications circuitry with the local area network. According to another aspect, this invention comprises a portable electronic device having communications capabilities, a switchable wireless communications device comprising a radio frequency modem, wireless communications circuitry, and an antenna operable to communicate over a wireless communications link with one of a local area network and a wide area network; and a proximity detection device operable to detect proximity of the device with the local area network, the wireless communications circuitry responsive to detection of the device within suitable signal communication proximity with the local area network to couple the communications circuitry with the local area network. These and other aspects of the invention are described in more detail with reference to FIGS. 1-6. The present invention provides a portable electronic communications device having a switchable local/wide area wireless communication network. Referring in more detail to the drawings, FIG. 1 illustrates a portable electronic communications device in the form of a personal computer, namely a notebook computer 10, having switchable wireless communications features that reduce operating costs when used in local geographic areas preferably on a privately owned (or user-run) Local Area Network (LAN). The computer has a thin panel display 12 housed within an upper case 14. A keyboard 16 and a tactile input device 18 are provided in a top face of a lower case 20. Upper case 14 is supported in pivotal relation with lower case 20 such that a user can move display 12 and upper case 14 from a closed, or stowed position to a vertically pivoted in-use position. FIG. 1 depicts computer 20 in an open, or in-use configuration. A whip antenna 22 is pivotally carried on an outer edge of upper case 14, enabling vertical orientation of the antenna regardless of orientation of upper case 14 by way of a pivot connection 24. As shown in FIG. 1, antenna 22 is connected with a coaxial radio frequency (RF) cable 26 to a cellular radio frequency (RF) modem 28 housed within lower case 20. Additionally, a traditional telephone modem 30 usable with a Public Switched Telephone Network (PSTN) system via a telephone line is also provided in lower case 20. Telephone modem 30 is typically used when a standard RJ-11 wall jack and telephone line are available to a user due to the lower use charges of the PSTN system. Accordingly, standard telephone line charges tend to be less expensive than wireless communication charges. Antenna 22 enables wireless communication via cellular radio modem 28, with antenna 22 and modem 28 being operable in both transmit and receive modes. Computer 10 is preferably a ruggedized laptop, or notebook computer suitable for use in mobile workforce environments such as warehouses, manufacturing facilities, assembly lines, testing facilities, mobile service vehicles, and any application requiring a waterproof and shock resistant portable computer. One such computer 10 suitable for modifying to implement the apparatus and method of this invention is an XC-6000 ruggedized notebook computer presently manufactured and sold by Itronix Corporation of Spokane, Wash. Details of such a ruggedized computer are similar to those disclosed in our U.S. patent application Ser. No. 08/499,488 filed on Jul. 7, 1995 and entitled, "Impact-Resistant Notebook Computer", listing inventors as William F. Erler, Jonathan L. LaMarche, David H. Stockham, and Theodore C. Vollmer. This application Ser. No. 08/499,488, which is now U.S. Pat. No. 5,706,168, is hereby incorporated by reference. Details of such a computer 10 having an internal radio are similar to those disclosed in Applicant's U.S. patent application Ser. No. 08/633,010 filed on Apr. 16, 1996 and entitled, "Electromagnetically Shielded Laptop Computer Having Internal Radio", listing the inventor as Jeff Delamater. This Ser. No. 08/633,010 application, which is now abandoned, is hereby incorporated by reference. Additional details of such a laptop computer and radio construction are even further disclosed in Applicant's U.S. patent application Ser. No. 08/623,945 filed on Mar. 19, 1996, and entitled "Laptop Computer Having Internal Radio With Interchangeable Antenna Features", listing the inventor as Jeff Delamater. This application Ser. No. 08/623,945, which is now U.S. Pat. No. 5,828,341, is hereby incorporated by reference. FIG. 1 illustrates notebook computer 10 in a partial breakaway perspective view, enabling visualization of internally housed wired and wireless radio communications features. Antenna 22, carried on the opened upper case 14, is shown pivoted to a vertically oriented position there along. Coaxial radio frequency (RF) cable 26 connects antenna 22 with communications equipment housed within lower case 20. RF cable 26 leaves upper case 14 through one of a pair of hinges, and enters lower case 20 through an LED board carried on the lower case, beneath a plastic trim cover. Radio modem 28, LAN/WAN switching circuitry 32, wireless communications circuitry 34 and a proximity detection device 36 are carried on a daughterboard within case 20. Telephone modem 30 is also mounted within case 20, beneath a motherboard. Preferably, a central processing unit 38, a microcontroller 40, and at least one form of memory device (not shown) are carried on the motherboard within case 20. Wireless cellular radio frequency modem 28 includes a radio, a receiver, and modulation and demodulation circuitry that connect via RF cable 26 with antenna 22. Radio frequency modem 28 is configurable to selectively transmit and receive radio signal-based information between computer 10 and another device, such as a similarly configured computer. Radio modem 28 is mounted on the daughter board via bosses to the bottom of lower case 20. Telephone modem 62 includes a telephone that is provided to enable direct telephone line connection with computer 20 via a receiving RJ-11 jack provided in the back of the computer. FIG. 2 illustrates a layout for a portable electronic communication device 10 having switchable mobile communications features of this invention provided variously by a processor 38/40, radio modem 28, LAN/WAN switching circuitry 32, wireless communications circuitry 34, antenna 22, and proximity detection circuitry 36. Processor 38/40 is preferably implemented via co-processing of cpu 38 and microcontroller 40. Alternatively, cpu 38 or microcontroller 40 can be individually used to implement the processor. Preferably, portable electronic communications device 10 is at least in part formed by a personal computer (PC) subassembly. Other parts of device 10 not shown can comprise testing components, data analysis components, various signal monitoring circuitry, and computer peripheral components. According to FIG. 1, telephone modem 30 forms part of a standard Public Switched Telephone Network (PSTN) which uses standard RJ-11 wall-mounted jacks, plugs and cables to connect telephone equipment with a telephone transmission line, or cable. Such features are made available to a user typically at a reduced transmission cost over using a mobile telephone transmission system, so use of modem 30 makes sense when a telephone jack is available to a user. Alternatively, radio modem 28 is provided along with wireless communications circuitry 34, antenna 22, LAN/WAN switching circuitry 34, and proximity detection device 36 for facilitating implementation of the features of Applicant's invention. Accordingly, processor 38/40 implements cellular data and/or voice communication via radio frequency modem 28, wireless communications circuitry 34 and antenna 22. LAN/WAN switching circuitry 32 is initialized via processor 38/40 to switch wireless communications circuitry 34 for communication with either a Local Area Network (LAN) 44 or a Wide Area Network (WAN) 42. Radio frequency modem 28 talks on WAN 42. Radio frequency modem 28 is implemented on WAN 42 in the form of a wireless radio frequency (RF) network radio modem. Suitable forms of such wireless radio frequency (RF) network radio modems are cellular, RAM™, ARDIS™, or any of a number of available wireless radio frequency (RF) communication systems. Wireless communication circuitry 34 is additional data/voice communication equipment necessary to configure modem 28 for selective communication with either WAN 42 or LAN 44. In order to determine whether wireless communications circuitry 34 should initialize radio frequency modem 28 for communication with WAN 42 or LAN 44, proximity detection device 36 determines whether device 10 is within an acceptable range to communicate with LAN 44. When proximity detection device 36 determines that device 10 is within an acceptable range, LAN/WAN switching circuitry 32, via commands from processor 38/40, configures wireless communications circuitry 34 for wireless communication with LAN 44, via antenna 48. When proximity detection device 36 determines that device 10 is outside an acceptable signal communication range with LAN 44, LAN/WAN switching circuity 32 configures wireless communications circuitry 34 for wireless communication with WAN 42, via antenna 46. According to FIG. 2, LAN 44 is preferably a user-operated Local Area Network comprising a collection of computers and wireless communications links provided within a work environment, such as a warehouse or an assembly line. More particularly, LAN 44 is user operated, eliminating any wireless radio frequency (RF) airtime charges being incurred by a user working within the warehouse. Similarly, LAN 44 can be configured for operation within a defined local geographic area having acceptable signal transmission characteristics. In this manner, users operating within the local geographic region can eliminate wireless radio frequency (RF) airtime charges when implementing a wireless communication link with LAN 44. Once the user leaves the acceptable range of LAN 44, proximity detection device 36 notifies processor 38/40, which initiates LAN/WAN switching circuitry 32 to switch the wireless communication link to WAN 42. When operating with WAN 42, cellular airtime charges will be incurred. As a user returns within the acceptable range of LAN 44, proximity detection device 36 detects an acceptable range, causing switching via circuitry 32 to a wireless communication link with LAN 44. According to one specific embodiment of a proximity detection device, FIG. 3 illustrates portable electronic communications device 10 having a radio frequency (RF) receiver 50 with an antenna 52 and a radio frequency power detector 54. Proximity detection device 36 determines whether device 10 is within an acceptable range by monitoring signal strength from LAN 44 via proximity detection device 36. More particularly, radio frequency (RF) power detector 54 comprises a signal strength detector communicating with processor 38/40 and RF receiver 50 to detect proximity of device 10 with LAN 44. LAN 44 has a proximity RF power transmitter 58 configured to send RF signals having a pre-selected frequency and strength via antenna 56 to antenna 52 of device 10. Power detector 54 detects the received power of the signal captured by antenna 52 and receiver 50 via RF signals sent via antenna 56. Based on the distance between antenna 56 and antenna 52, the detected signal strength will vary. As distance increases, detected signal strength decreases. As distance decreases, detected signal strength increases LAN 44 also includes wireless communications circuitry 60 for sending and receiving data/voice communication signals via antenna 48 with communication devices such as device 10. Optionally, antennas 48 and 56 can be combined into a single antenna. According to FIG. 3, the proximity detection device 36 operates by monitoring radio frequency (RF) signal strength coming from the base, or local area network (LAN) 44 via antenna 56 and transmitter 58. By looking at the RF power received via antenna 56, namely by looking at the amplitude of the analog signal via analog circuitry, the value can be converted via an analog to digital (A/D) converter, then processed by processor 38/40 to evaluate signal strength. Preferably, microcontroller 40 is used to evaluate a data stream from an analog to digital (A/D) converter. According to one construction, radio frequency receiver 50 has a receive signal strength indicator provided therein. The receive signal strength indicator can assess signal amplitude which is proportional to the amount of RF power received from LAN 44 via antenna 56. Hence, the receive signal strength indicator can also be used to assess the proximity of device 10 with LAN 44. Alternatively, radio frequency (RF) receiver 50 and radio frequency (RF) power detector 54 can be incorporated internally within wireless communications circuitry 34. For example, receiving circuitry of receiver 50 and a signal strength detector of detector 54 can be formed internal to wireless communications circuitry 34. Such an implementation would save costs, and antennas 52 and 56, as well as transmitter 58, would be eliminated. Instead, antenna 22 would be used with receiving circuitry 50 in order to detect received signal strength from antenna 48. Such would prove to be a more cost-effective implementation. However, the implementation depicted in FIGS. 2 and 3 better depicts the functionality associated with the implementation. Also according to the FIG. 3 construction, an acceptable threshold signal strength level is predetermined by a user for transmitting data to transfer between antenna 22 and antenna 48 of LAN 44. Once the data stream becomes corrupted, an associated threshold signal level between antenna 52 and antenna 56 will cause switching circuitry 32 to reconfigure wireless communications circuitry 34 for communication via antenna 22 with WAN 42. In this manner, the less expensive LAN 44 can be used with device 10 when operating within the local geographic region. Once beyond the bounds of LAN 44, circuitry 34 is switched to communicate via wireless communication link with WAN 42. In this manner, proximity detection device 36 forms a proximity sensor that toggles between LAN 44 and WAN 42 as a user of device 10 crosses over a perimeter region, or boundary marker, that is defined by transmitted signal strength between antennas 52 and 56. Additionally, when implementing the proximity detection device 36 of FIG. 3, screen 12 (of FIG. 1) can be used to display messages and/or graphics which signal to a user that they are crossing a signal limiting barrier by exceeding an acceptable threshold signal between antennas 52 and 56. According to one version, the computer screen notifies a user, and switching between LAN 44 and WAN 42 still occurs automatically. According to another implementation, a user is notified visually via the computer screen, as well as via a speaker on computer 10, and a user is prompted to respond by manually keying in reconfiguration of communications circuitry 34 for transferring between LAN 44 and WAN 42. According to the implementation of FIG. 3, device 10 looks at radio frequency power received by antenna 52 from antenna 56 of LAN 44. One example involves setting a threshold RF power value of 90 dBm (or 90 decibels below one milliwatt). When RF power received drops below the 90 dBm threshold, switching circuitry 32 switches communication to WAN 42, between antennas 22 and 46. According to this implementation, receiver 50 and antenna 52 are always detecting the presence of signals from antenna 56 of LAN 44, to determine when a user leaves the acceptable range of LAN 44, and returns within the acceptable range in order to selectively switch between WAN 42 and LAN 44. FIG. 4 illustrates an alternative specific embodiment of a proximity detection device 36 (of FIG. 2). Namely, proximity detection of a portable electronic communications device 110 is implemented via a processor 38/40, radio frequency modem 28, LAN/WAN switching circuitry 32, wireless communications circuitry 34, and antenna 22 set up similar to that described in FIG. 3. Additionally, a radio frequency (RF) receiver 50 and a data stream error detecting algorithm 62 communicate, along with processor 38/40 to implement proximity detection. An antenna 52 receives RF signals from antenna 56 of LAN 44. Data stream error detecting algorithm 62 is implemented via processor 38/40 to detect bit stream errors in the received RF signals delivered by receiver 50. A detected increase in bit stream errors indicates a loss in quality of the wireless communications link, requiring transfer to WAN 42. As distance between antenna 52 and antenna 56 increases, the number of bit stream errors will also increase. Therefore, proximity detection can be implemented by monitoring the number of bit stream errors being detected. Such implementation forms another technique for monitoring the existence of a healthy communications signal providing the communications link between base, or LAN 44, and antenna 22 of device 110. In this manner, processor 38/40 looks for an error correction coding sequence, counting the number of corrupted bits. When the number of errors increases, device 110 switches to form a communications link with WAN 42. One suitable error detecting algorithm is implemented by embedding error correcting code built into the data being received from LAN 44 via antenna 56. The simplest technique involves detecting bit errors. One such code is CHECKSUM, a cyclic redundancy code. Another is Reed Solomon code. Alternatively, any type of error detecting and/or correcting algorithm can be used. Such monitoring of the integrity of data streams received by receiver 50 and antenna 52 involves base band analysis, and does not involve radio communication, per se. Alternatively, the error correcting code could be embedded in the data stream between antennas 22 and 48, eliminating the need for antennas 52 and 56. FIG. 5 illustrates another alternative specific embodiment of a proximity detection device 36 (of FIG. 2). Namely, proximity detection of a portable electronic communication device 210 is implemented via a processor 38/40, radio modem 28, LAN/WAN switching circuitry 32, wireless communications circuitry 34, and antenna 22 set up similar to that described in FIG. 3. A first radio frequency (RF) receiver 64 and a second radio frequency (RF) receiver 66 cooperate with RF antennas 68 and 70, respectively, to provide the specific embodiment of a proximity detection device according to this implementation. More particularly, a first radio frequency transmitter 72 and a second radio frequency transmitter 74 are provided within LAN 144 signally connected with antennas 76 and 78, respectively. RF transmitter 72 emits an RF transmitting signal via antenna 76, having a first transmission frequency (f 1 ). Likewise, the second RF transmitter 74 transmits a second RF signal via antenna 78, having a transmitting frequency of (f 2 ). RF receiver 64 is configured to receive the transmitted signal from antenna 76 via receiving antenna 68. Similarly, RF receiver 66 is configured to receive the transmitted RF signal from antenna 78 via receiving antenna 70. According to the construction of FIG. 5, antennas 76 and 78 are preferably laid out along a desired periphery of a local geographic area in which LAN 144 is desired to operate in wireless communication link with portable electronic communications device 210. According to this construction, antenna 76 is laid within the periphery of antenna 78, but parallel to the layout. Preferably, antennas 76 and 78 are laid out immediately adjacent to one another. By constructing antennas 76 and 78 to emit distinct frequencies, receivers 64 and 66 can discriminate the antennas to enable detection of when a user transports device 210 outside/inside of the desired geographic area of wireless operation for LAN 144. If a single wire (of antenna 76 or 78) is utilized in conjunction with a single receiver (of receiver 64 or 66), it is possible that a user might leave/enter the bounded area of the antenna in the region without being detected. Accordingly, device 210 would not recognize whether it is within the desired geographic location for use with LAN 144, or should be configured for communication with WAN 42. By providing a pair of antennas 76 and 78 and receivers 64 and 66, device 210 can discriminate whether it is leaving or entering the desired geographic operating region of LAN 144. Hence, antennas 76 and 78 and receivers 64 and 66 enable processor 38/40 to determine in which direction device 210 is crossing the operating boundaries of LAN 144. Alternatively, a single one of antennas 76 and 78 and receivers 64 and 66 can be utilized to implement the proximity detection device of FIG. 5. However, with such a construction, it will be important to determine that device 210 be able to detect the RF signal from the antenna with each pass across its boundary. One example of a case where device 210 can "slip by" the antenna would be where a battery power-supplied device 210 is completely exhausted, disabling receiver 64. Further alternatively, the device depicted in FIG. 5 can be implemented such that transmitter 72 and transmitter 74 operate at the same frequency, such that f 1 equals f 2 . To distinguish antennas 76 and 78, transmitter 72 drives antenna 76 according to one modulation scheme, whereas transmitter 74 drives antenna 78 at a second, and different, modulation scheme. Receiver 64 is configured to detect the modulation scheme received from transmitter 72 and antenna 76, whereas receiver 66 is configured to detect the modulation scheme received from transmitter 74 and antenna 78. Even further, alternative constructions for proximity detection device 36 (of FIG. 2) include use of a Global Positioning Satellite (GPS) receiver to detect proximity of a portable electronic communications device with a local area network. By providing a GPS receiver within a portable electronic communications device, the device can detect its proximate location relative to a transmitter of the local area network. One way is to assign position of the local area network transmitter as a way point, or reference point, in memory of the GPS receiver. The GPS receiver, operating off satellite signals, can accurately determine location of the device with reference to the way point. Hence, knowledge of transmitting and receiving signal integrity between the device and the local area network allows one to define a radius in which the local area network can be utilized by the device. Once outside of the radius, the device can reconfigure a wireless communication link with a wide area network. Alternatively, any device which allows for detection of proximity relative to a local area network can be utilized. In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.

A portable computing device has a computer programmed to store and communicate information and a housing configured to house the computer. A communications device, provided in the housing, is controlled by the computer and configured to communicate information between the computing device and a remote computer. An antenna is carried by the housing and is configurable to electrically couple with the communications device for communicating radio frequency information with the remote computer. A signal coupling device is carried by the housing and is configured to removably mate in signal transmitting relation with an external antenna via a complementary mating signal coupling device. A switch provided with the device is constructed and arranged to selectively connect the communications device with one of the dedicated antenna and the external antenna. According to one aspect, this invention comprises a portable electronic communications device, comprising a radio frequency modem, wireless communications circuitry, and an antenna operable to communicate over a wireless communications link with one of a local area network and a wide area network; and a proximity detection device operable to detect proximity of the device with the local area network, the wireless communications circuitry responsive to detection of the device within suitable signal communication proximity with the local area network to couple the communications circuitry with the local area network.

This application is a continuation-in-part, of now abandoned application Ser. No. 907,999, filed Sept. 16, 1986. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support device for the construction of movable covers for various purposes, for example for covering terraces or verandas, or the temporary closing of vertical front walls. 2. Description of the Related Art The existing systems usually comprise at least two lateral uprights each of which is formed by rectilinear portions constituted by metal section members, between which there are interposed curved parts, whereby it is possible to give the desired profile to the assembly. The lateral uprights, between which is displaced a movable element formed for example by a sheet, are used in particular for the mounting of an intermediate structure supporting the movable element. This intermediate structure may be formed, on one hand, by a support tube including electrical or manual means for driving the movable element, and on which is fixed one of the ends of said movable element, and, on the other hand, by a load bar fixed to the other end of the movable element. The load bar is movable between the two lateral uprights in a slideway and ensures the traction of the movable element. Furthermore, the movable element when in the deployed position is maintained by supports, termed windbreaks, which are evenly spaced apart transversely between the two lateral uprights. Each windbreak comprises a tube whose ends are fitted onto a sleeve mounted to be freely rotatable on a pin fixed inside each lateral upright. But these known systems have many drawbacks. First of all, the support tube for the movable element is mounted by means of a special member which is fixed to the end of the lateral uprights and is also employed for the fixing of the assembly to a wall. This arrangement consequently does not allow the support tube to be displaced along the uprights or to be mounted in another place nor does the arrangement facilitate the mounting of several support tubes (i.e. separate intermediate structures) one after another in a vertical direction extending along the uprights. Thus, the possibilities of installation are limited. Furthermore, the curved parts interposed between the rectilinear metal section members are also formed by special members usually fixed by being bolted to the rectilinear section members. These members have a predetermined curvature and do not permt a modification of the angles of the curved parts of the lateral uprights. Moreover, in the case of special installations which do not correspond to a current profile, i.e. which include special angles, it is necessary, depending on the angle to be obtained, to specially machine a member having the desired curvature which increases the cost of the installation. Lastly, the windbreak is fixed by drilling and by being bolted through the lateral uprights in given places so that when it is desired to modify the position of these windbreaks, the lateral uprights must be again drilled, and this of course has an adverse effect on the appearance and the strength of the assembly. SUMMARY OF THE INVENTION An object of the present invention is to avoid the drawbacks mentioned above and to provide a device whose construction is less expensive and whose utilization is simpler than that of known systems. The present invention therefore provides a device for supporting movable cover elements comprising at least two longitudinal uprights formed by rectilinear and/or curved parts which are juxtaposed in series, said uprights permitting the mounting of an intermediate structure constituted by a support tube for the movable element, a load bar fixed to one of the ends of said movable element and slidable between the longitudinal uprights, and a plurality of tubes or windbreaks evenly spaced apart between said uprights for the support of the movable element in the deployed position, wherein the rectilinear and/or curved parts of the longitudinal uprights are formed, thoughout their length, by a section member of the same section forming a continous assembly. The support device comprises, on one hand, means for fixing the various elements of the intermediate structure at any point and movable by sliding along said uprights and, on the other hand, means for interconnecting said various rectilinear and/or curved parts. According to another feature of the invention, the section member in the curved parts is formed by at least one small section of the same section member whose transverse surfaces intersect at a predetermined angle. BRIEF DESCRIPTION OF THE DRAWINGS The following description, given by way of non-limiting examples and shown in the accompanying drawings, will bring out the advantages and features of the invention. In the drawings: FIG. 1 is a diagrammatic exploded perspective view of a first embodiment of the device according to the present invention; FIG. 2 is a sectional view taken in a plane transverse to the longitudinal axis of the upright of the first embodiment; FIG. 3 is a diagrammatic exploded perspective view of a second embodiment of the device according to the present invention; FIG. 4 is a sectional view taken in a plane transverse to the longitudinal axis of the upright of the second embodiment; FIG. 5 is a longitudinal cross-sectional view taken through an intermediate structure showing an upright and the relative positions of the different elements comprising the intermediate structure; FIG. 6 is a diagrammatic exploded perspective view of a rectilinear part and a curved part of an upright according to the first embodiment of the present invention; FIGS. 7 and 8 are two perspective views of two embodiments of the connecting means between the curved parts and the rectilinear parts of the upright; FIG. 9 is a view similar to FIG. 2 in which the elements of the intermediate structure supporting the movable element are diagrammatically represented; FIG. 10 is a view similar to FIG. 4 in which the elements of the intermediate structure supporting the movable element are diagrammatically represented; FIG. 11 is a cross-sectional view of an upright showing a modification of a device according to the present invention; FIG. 12 is a plan view of a second modification of a device according to the present invention, and FIG. 13 is a plan view of a third modification of a device according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, the device for supporting movable cover elements comprises two longitudinal uprights 1 and 2 from each other. These uprights 1 and 2 are symmetrical with respect to each other and are each formed by rectilinear parts and curved parts constituting the framework of an assembly for covering terraces or verandas for example. Each upright 1 and 2 is fixed, for example, to a wall by a bracket 5. Mounted between the two uprights 1 and 2 is an intermediate structure generally designated by the reference numeral 30, which supports a movable cover element 31 for example a sheet. The sheet 31 is wound around a support tube 32 including means for rotating the tube. These rotating means in the embodiment illustrated in FIG. 1 are formed by a small motor 33 incorporated in the tube 32, and may also be formed by a manual system actuated, for example, by a crank. The tube 32 further comprises on its outer periphery a longitudinal groove 34 for fastening one of the ends of the sheet 31. Each end of the tube 32 is fitted on a sleeve 35 having a central orifice 36. The free end of the sheet 31 is secured to a load bar 37 movable between the uprights 1 and 2, as will be understood hereinafter. This load bar 37 consists of a tube provided on its outer periphery with a longitudinal groove 33 for securing the free end of the sheet 31. The ends of the tube of the load bar 37 are fitted on a sleeve 39 having a central orifice 40. For the purpose of supporting the sheet 31 in the deployed position, the intermediate structure 30 includes windbreaks 41 judiciously spaced apart between the uprights 1 and 2. The windbreaks 41 are each formed by a tubular member, fitted at each end on a sleeve 42 provided with a central orifice 43, and are mounted to be freely rotatable on the uprights 1 and 2. The rectilinear and/or curved parts of the longitudinal uprights 1 and 2 are constituted, throughout their length, by assembled discrete sections of a given section member 10 of so that each section has the same sectional shape which is shown in cross-section in FIG. 2. This section member 10, which is, for example, fabricated from metal or a plastics material, has a vertical inner partition wall 11 which defines a vertical plane of symmetry P. On each side of this vertical partition wall 11 horizontal walls 12, 13, 14 form, in the longitudinal direction of the section member and one below the other, respectively a groove 15 and groove or slideway 16. Below the horizontal wall 14, the section member 10 has, on each side of the plane of symmetry P, two parallel vertical partition walls 17 and 18 which extend downwardly and define a longitudinal central cavity 19 defined in its lower part by a horizontal inner plate 20. On the outer surface of the vertical partition walls 17 and 18, horizontal walls 21 define therebetween a plurality, for example four, of superimposed longitudinal grooves 22a, 22b, 22c, 22d. The ends of the horizontal walls 12, 13, 14, and 21, are provided with small vertical flanges 23 which partly close the grooves 15 and 22 and the slideway 16 while defining therebetween a sufficient opening for the mounting of the intermediate structure 30. In the first embodiment illustrated in FIGS. 1 and 2, the section member 10 therefore includes, throughout its length, symmetrically relative to the plane P and on each lateral side, an upper groove 15, a slideway 16 and four small grooves 22a, 22b, 22c, 22d in superimposed relation to one another. The dimensions and the distances between the axes of the grooves and the slideway are chosen to satisfy required standards. As mentioned before, the uprights 1 above and 2 formed by assembled sections of a section member 10 having a contour when viewed in a vertical plane of the uprights which may include rectilinear and/or curved parts. Depending on the length of the rectilinear parts, these parts may have a plurality of sections of the sections members which are in juxtaposed series relation to one another. In this case, the ends of the sections of the section member may be beveled to create a ridge angle which increases the rigidity of the assembly. Several devices may be placed adjacent to one another and may be linked together as will be further described with reference to FIG. 3. FIGS. 3-5 show a second embodiment of the device for supporting movable cover elements. The intermediate structures shown in FIG. 3 are the same as in the first embodiment and therefore, the corresponding elements have the same reference numerals. Thus, the intermediate structure of each device comprises a support tube 32, several windbreaks 41 and a load bar 37. FIG. 3 further shows several adjacent devices linked together to form an assembly. The devices are disposed in an adjacent relation with respect to both the horizontal and the vertical and are interconnected through intermediate, common uprights 101. Each common upright 101 supports two devices disposed side by side with respect to the horizontal and can also, as shown in FIG. 3, support two or more devices placed one after another with respect to the vertical. As in the first embodiment, the uprights 101 according to the second embodiment comprise rectilinear and/or curved parts constituted, through their length, by a section member 102 having the same sectional shape which is shown in cross section in FIG. 4. This section member 102, which is comprised of metal or a plastic material, for example, has a symmetric structure and comprises a central rectangular part consisting of two parallel vertical partition walls 103 interconnected by two horizontal inner plates which collectively define a longitudinal central cavity 105 extending throughout the length of the uprights 101. The section member 102 furthermore comprises horizontal walls 106 extending outwardly from the vertical partition wall 103 and defining together therewith several grooves 107a, 107b and a groove or central slideway 108 on each longitudinal side of the upright 101. The ends of the horizontal walls 106 are provided with small vertical flanges 109 which partly enclose the grooves 107a, 108b. The upper and lower flanges have at their outer ends a horizontal wall 110 projecting inwardly and defining grooves 111 and 112 with the horizontal inner plates 104. The upper and lower grooves 11 and 112 can be T-shaped as shown in FIGS. 4, or they can also have the same rectangular shape as do the side grooves 107a, 107b. The openings of the side grooves 107a, 107b are sufficient for the mounting of an intermediate structure on one or both sides of an upright. The upper and lower grooves 111 and 112 can cooperate with fixing or holding devices. FIG. 5 is a longitudinal cross-sectional view taken through an intermediate structure showing an upright 101 and the position of the different elements comprising the intermediate structure. At the top of the figure, a support tube 32 is mounted in a central slideway 108. The upright is then slightly inclined inward and a windbreak 41 is placed in a lower side groove 107b in the middle of a curved section. Then another curved section providing an inward inclination is provided and a windbreak 41 is disposed in the same way as in the first one, i.e. in the lower side groove 107b in the middle of the curved section. The upright 101 is then inclined slightly outward and a windbreak 41 is placed in the upper side groove 107b. A load bar 37 is movably mounted in the central slideway 108 between the windbreaks in the upper and lower side grooves 107a and 107b. A second support tube 32 is mounted in the central slideway 108 below the third curved section. In the substantially curved sections of the first and second embodiment (FIGS. 1, 3 and 6), the uprights 1, 2 and 101 are formed by a plurality of small rectilinear sections 10a and 102a, respectively, of the section members 10 and 102 which are pre-cut in such a manner that the transverse end; surfaces of each small section 10a make therebetween an angle A whose apex faces the centre of curvature. This angle A is for example equal to 10°. Consequently, in accordance with the desired curvature, it is sufficient to juxtapose in series relation a plurality of small sections 10a, 102d of the section member. In the case where the desired curvature does not exactly correspond to the various possibilities with sections at 10°, the fitter may cut directly on the site the end of the rectilinear section. For example, if the angle to be formed is equal to 85°, the fitter will juxtapose eight 10° sections so as to form an angle of 80° and will cut the end of the rectilinear part of the upright at 5°. Since the rectilinear parts and/or curved parts of the uprights 1 and 2 are formed by identical sections of section members having the same sectional shape, on each lateral side of said uprights a group of grooves and slideways are provided which are perfectly continuous. The various sections 10, 10a and 102a, respectively of of common given section member are maintained in position by a connecting means 50 which extends through the interior of the central cavity 19 of each section, as shown diagrammatically in FIG. 6. With reference now to FIGS. 7 and 8, this connecting means will be described in more detail. The connecting means 50, whose width and thickness substantially correspond to the dimensions of the cavity 19, comprises at least two links 51 which are articulated together (FIG. 7) so that the connecting means is bendable in a vertical plane passing through the respective upright. Each link 51 is formed by two plates 52 and 53 each of which has a rounded end portion provided with an aperture 54 and a straight end. The two plates 52, 53 are fixed together in head-to-toe relation and slightly offset in the longitudinal direction so as to form at each end of the link a flat face 55 against which the end portion of the following link is applied. The links 51 are articulated together by a small pin 57 extending through the apertures 54 so as to form a continuous articulated chain element. It will be clear that each link 51 may be formed by a single machined member having in each of its end portions a flat face and an aperture. Furthermore, one of the links may also be formed by a longer member 56 having a given curvature, as shown in FIG. 8. The juxtaposition of the sections 10 and 10a of the section member is achieved by introducing the articulated links 51 into the cavity 19, which thus centers the various sections with respect to one another in accordance with the desired curvature the links automatically adapting themselves to this curvature as shown by the correctly assembled juxtaposed sections of the upright on the right side of the device shown in FIG. 1. FIG. 6 is a cross-sectional view of a section 10 of a section member on which the various component parts of the intermediate structure supporting the movable cover are fixed. Bearing in mind the symmetry of the section member 10, all the elements may be fixed on the same side, for example in the case where the section member constitutes a lateral upright, or on both sides, in the case where the section member constitutes an intermediate upright for supporting a movable cover on each side. The sleeve 35 of the support tube 32 for the sheet is mounted on a pin 60 integral with a plate 61 fixed in the grooves 15 and 22a of the section member in such manner that the axis of the support tube 32 is placed on the axis of the slideway 16. The plate 61 is fixed in each groove by a quarter-turn clamping system 62 comprising a screw 62a cooperating with a nut or a pellet 62b placed in the corresponding groove. When assembling, the end of the screw 62a bears against the inner end of the groove, which is effective to locate the nut 62b against the inner flanges of said groove. The tube 37 of the load bar is fitted on the sleeve 39 in which is mounted a pin 63 having at its opposite end a roller 64 which penetrates the slideway 16 in such manner that the load bar can be moved along said slideway. The axes of the support tube 32 and the load bar are therefore located in the same plane. The windbreaks 41, each comprising a tubular member fitted at each end on the sleeve 42, are fixed in the grooves 22d of the section member also by means of a quarter-turn clamping system 65. This system 65 comprises a screw 66 whose head 67 is placed inside the sleeve 42. The body of the screw 66 extends through the sleeve 42 in the aperture 43 and clamping lock-nuts 68 are screwed on the body of the screw 66 from the other side of the sleeve. The windbreak 41 is fixed in the groove 22d by a nut or a pellet introduced in said groove. When assembling, the end of the screw screwed into the nut 69 bears against the inner end of the groove 22d, which is effective to locate the nut 69 against the flanges of said groove 22d. The clamping is completed by means of lock-nuts 68. The windbreak is therefore fixed in position by turning the screw 66 through a quarter of a turn. Since this manner of securing the intermediate structure, and in particular the support tube 32 and the windbreaks 41, solely by a quarter-turn clamping screw and nut system cooperating with a groove of the section member, no drilling of said section member is required and the supports may be placed in any position along the uprights and may be above all shifted as desired by sliding without any particular requirements. FIG. 10 is a cross-sectional view of a section member 102 on which the various component parts of the intermediate structure supporting the movable cover are fixed. These component parts are described in detail with reference to FIG. 9. According to the second embodiment as well as to the first one, these elements may be fixed on just one side of the upright, or on both sides thereof when the section member is used as an intermediate upright for supporting a movable cover on each side thereof. The pin 60 of the support tube 32 is integral with a plate 113 fixed in the grooves 107a and 107b of the section member in such a manner that the axis of the support tube 32 extends along an axis of the central slideway 108. The plate 113 is fixed in each groove by the same quarter-turn clamping system 62 as described above with reference to FIG. 9. The pin 63 of the load bar 37 has a roller 64 at one end thereof which is disposed in the slideway 108 in such a manner that the load bar can be moved along said slideway. The windbreaks 41 are fixed in the grooves 107a and 107b of the section member by means of a quarter-turn clamping system 65 of the same type as described above with reference to FIG. 9. The clamping is completed by means of lock-nuts 68. Furthermore, the grooves 22b, 22c, and 107a, 107b, respectively, may be employed for securing other elements, such as for example rollers of a cable or a belt driving the load bar. The other elements are also mounted by means of a quarter-turn clamping system. If a single piece cover having a large width is required, the same section member 10 is employed, but in an inverted position as shown in FIG. 11. Indeed, this arrangement enables a single load bar 37 fixed to a carriage 70 to be mounted on top of the section member. The carriage 70 is moved along the section member in the groove 22d by means of small wheels 71. In accordance with the diameter of the tube 41 of the windbreaks, said windbreaks are secured in the grooves 22a, 22b, or 22c also by means of a quarter-turn clamping system so that the tube 41 extends beyond the top of the upper surface of the section member 10 for supporting the sheet. In this arrangement, it is also possible to superimpose two sheets as, for example, a fine sheet of the mosquito-net type in the lower part of the section member in the region of the groove 15 and, above, a movable water-tight sheet driven by the load bar 37. The device according to the invention may be used for closing off vertical front walls by means of a movable sheet or blind. The uprights 1 and 2 are vertically secured to a front wall 6 (FIG. 8) for example on each side of 12 row of windows 7 on several floors. A single sheet may close the windows in several floors and, in this case, a support tube is mounted in the upper part of the uprights and a load bar descends throughout the height. If it is desired to close off the windows of each floor separately (FIG. 12), a support tube is placed between each floor and a load bar 37 connected to a sheet 31 is moved. This arrangement with a plurality of support tubes 14 and a load bar on the same uprights is possible due to the fixing of the support tubes directly on the section members of the uprights with no use of an intermediate element. The device according to the invention may also be used for closing off and supporting glass panes of verandas or glass roofs or casings. In this case, the section member 10 includes, in addition to the means for supporting the sheet, means for supporting the panes of glass 70 and sealing elements (FIG. 9). For this purpose, the section member is provided, throughout its length in a symmetrical manner with respect to the plane P and on each lateral side, with a small groove 71 in which is placed a sealing element 72 which has for example a lip portion applied against the pane of glass 70. For the purpose of supporting the pane of glass 70, the section member 10 has in its lower part a small horizontal plate 73 including, on each side of the plane of symmetry, a longitudinal cavity in which a sealing element 75 is mounted. The pane of glass 70 bears against the sealing element 75. The device according to the invention therefore provides a continuity of the section member throughout the length of the uprights and also permits the construction of all possible arrangements, which increases the possibilities of installation. Furthermore, the installation is extremely flexible and easy to construct, since it does not require drilling or the use of special fastening elements.

A device has at least two longitudinal uprights (1, 2) each of which is made up of a series of juxtaposed aligned discrete sections of a given section member through which a throughway longitudinal cavity and grooves parallel to the cavity are defined. An elongate connecting device extends through the cavities of the sections and maintains them in alignment and assembled to one another. These uprights (1, 2) support transverse members (41) of an intermediate structure (30), the transverse members being engaged in the grooves of the sections. Fixing devices slidable in the grooves of the sections fix the transverse members (41) in position. Each upright may have rectilinear parts interconnected by at least one curvilinear part. The rectilinear parts consist of a single section of the section member while the curvilinear parts consist of a plurality of small sections (10a) of the section member having end faces that are convergent toward the center of radius of the desired curve.

CROSS-REFERENCE TO RELATED APPLICATION This is a continuation application of PCT/NL00/00271 filed Apr. 26, 2000, which PCT application claims priority on NL application number 1011915 filed Apr. 28, 1999, herein incorporated by reference. FIELD OF THE INVENTION The invention relates to an ice cube apparatus which is designed in particular as a desktop and/or stand-alone unit and is intended in particular for the consumer market. BACKGROUND OF THE INVENTION An ice cube apparatus is known, for example, from U.S. Pat. No. 4,055,053 which, in FIG. 8, shows a housing in which there is a mould chamber. The base of the mould chamber is largely formed by a plurality of mould trays which, on the underside, are connected to thermoelectric elements. The mould chamber is permanently connected to a water system and is kept permanently completely full of water with the aid of a float system. Consequently, the mould trays are always automatically full of water. After the apparatus has been switched to a freezing position, the thermoelectric elements ensure that the water in the mould trays freezes. Then, the power supply to the thermoelectric elements is interrupted, or alternatively these elements are temporarily switched to a heating state, so that heat is supplied to the mould trays for a short time. As a result, the outermost layer of ice melts and the ice cubes are free to float upwards in the mould chamber. The ice cubes can be scooped out of the top side of the mould chamber into an ice bucket with the aid of a chain drive with scoop blades. A drawback of this known apparatus is that the time which elapses between when the apparatus is switched on and a first series of ice cubes is ready is relatively long. Furthermore, the apparatus comprises a large number of mechanical components, is relatively expensive to produce and is unwieldy. The apparatus can only function with a mould chamber which is completely full, since otherwise the ice cubes which have floated upwards cannot be scooped out of the apparatus. To achieve this, the mould chamber has to be permanently connected to a supply system. The ice cubes which have already been produced remain floating in the water and slowly melt. Furthermore, use of the apparatus is unhygienic, since any contamination remains in the mould chamber and is continuously mixed with fresh water. Further, FR-A-2,747,769 shows in FIGS. 1 and 2 an apparatus for preparing cold water and ice. Water at ambient temperature can be fed from water bottles which are to be placed on top of the apparatus to a collection bin located inside the apparatus. In a variant, the apparatus may also be connected directly to a water supply system. A controllable valve is provided between the water bottles or the water supply system and the collection tray. From the collection tray, water can be passed via a pump, a system of pipes and a controllable valve to either an external tap or a distribution pipe located inside the apparatus. The distribution pipe is provided with a large number of spray nozzles which are situated just above a cooling body. The cooling body is formed by an inclined, elongate plate with transverse partitions. The spray nozzles atomize water over the cooling body. At one end, the cooling body is connected to a peltier element. In the freezing position of the peltier element, a small amount of the water which reaches the cooling body can freeze on the said body and can grow in layers to a limited extent. The water which does not freeze immediately falls downwards from the cooling body as cooled drops of water and enters the collection bin. At set times, the current direction to the peltier element is reversed, with the result that the bottom layers of ice on the cooling body melt and the discs of ice lying above it slide off the inclined plate and fall onto a collection grate which hangs above the collection tray. On this grate, the discs of ice will begin to melt, the melt water dropping into the collection tray. It should be noted that this apparatus is intended in particular for the preparation of cold water. The formation of discs of ice is simply a side effect. On the cooling body, it is only possible to freeze ice with a maximum thickness of a few millimeters. The first layers of ice which freeze on the cooling body at the beginning of a freezing cycle provide so much insulation that further progressive growth of ice is impossible. Consequently, only thin discs of ice can be formed. The thin discs of ice will melt away quickly, both on the collection grate and when they are finally used. For this type of combination apparatus, this is more of an advantage than a disadvantage, since the cold melt water contributes to reducing the temperature of the water in the collection bin, which can then be tapped into a glass as cold water via the tap. However, quickly melting discs of ice are very disadvantageous for an ice cube apparatus according to the present invention. This is because in this case cold melt water is an undesirable by-product. The principal product is the production of ice cubes. Therefore, a drawback of the apparatus described in FR-A2,747,769 is that only a small amount of the water supplied can be effectively converted into ice. Moreover, the ice is of low quality, i.e. it melts very quickly without dissipating much coldness. A further drawback is that the apparatus can only be used in combination with the special bottles which are to be placed on top of the apparatus, or has to be permanently connected to a water supply system. The bottles limit the versatility of the apparatus and, moreover, make it unwieldy and unstable. The water supply system also limits the versatility of the apparatus and, moreover, means that it has to remain in one place. A long time is required to make a first quantity of thin discs of ice. The apparatus has a long start-up time. The water comes out of the bottles at ambient temperature and passes directly into the collection bin, in order then to be cooled slowly by being mixed with water which has been cooled using the cooling body or with melt water. Discs of ice of some thickness can only be made after a sufficiently low temperature of the water in the collection bin has been reached. The mixing is not only slow but also unhygienic, since mixing often takes place with water which has already spent a long time in the apparatus. The thin discs of ice are therefore to a large extent formed from old water. SUMMARY OF THE INVENTION The object of the present invention is to provide an apparatus with which the only principal product made is ice cubes and in which the above drawbacks are eliminated. In particular, the invention aims to provide an ice cube apparatus which is inexpensive, compact and operates quickly and hygienically and is suitable in particular for the individual consumer who wants to make a small number of ice cubes from fresh water within a short time. According to the invention, this object is achieved by means of an ice cube apparatus for producing ice cubes, comprising a water reservoir, a housing, a freezing element which is separate from said water reservoir, pump means for supplying water from said water reservoir to said freezing element, at least one thermoelectric element which is connected in a thermally conductive manner to said freezing element, control means with a timer unit for providing current to said thermoelectric element for a defined freezing time, in such a manner that this element extracts heat from said freezing element, removal means for collecting ice which comes from said freezing element, wherein said water reservoir is located entirely inside said housing and comprises a filling opening, via which said water reservoir can be filled with a desired quantity of water, said freezing element being an ice cube tray which comprises at least one set of a base part and vertical wall parts which, together, delimit a mould cavity having a volume with a depth which is greater than or equal to one centimeter, said pump means being designed to supply said mould cavity with an amount of water which substantially corresponds to said volume of said mould cavity from said water reservoir at a start of a freezing cycle, release means being provided for releasing a frozen ice cube from said mould cavity after said freezing time. The apparatus comprises a thermoelectric element and an ice cube tray which is connected thereto in a thermally conductive manner. The apparatus is provided with its own internal water reservoir which, at the start of a production cycle, can be filled once with a desired amount of water. From the reservoir, the water can be metered to a mould cavity of an ice cube tray with the aid of water-metering means, for example a pressure pump. The mould cavity is at least one centimeter deep and consequently is suitable for the production of ice cubes with a thickness of greater than one centimeter. Control means with a timer unit then ensure that the thermoelectric element is supplied with current for a defined, set freezing time, in such a manner that heat is extracted from the ice cube tray. On the other side of the thermoelectric element, this heat is released again to the environment. After the freezing time has elapsed, release means which release the ice cube from the tray come into operation. The ice cube is collected and removed by removal means which are arranged beneath or next to the tray. The apparatus may comprise its own battery power supply or may be equipped with a plug for connection to an electricity grid. Consequently, the invention provides an ice cube apparatus which operates completely independently. The apparatus simply has to be switched on after the water reservoir has been filled with a defined amount of water. The amount of water can be adapted to the desired number of ice cubes. Then, the apparatus will produce a plurality of ice cubes in succession, in a continuous process, which are collected and removed via the removal means. The apparatus is structurally simple, inexpensive to produce and hygienic to use. The various components interact virtually without any noise and make it possible to construct an apparatus of very small dimensions, for example with a housing which holds the various components and measures 15×15×25 cm. Consequently, the apparatus is eminently suitable for use at home and in hotel rooms and the like. The use of mechanical components, such as controllable valves, is limited, which increases the reliability of the apparatus and means that maintenance is limited to a minimum. Surprisingly it has been found that the time which is required to produce a series of ice cubes of standard size, for example approximately 8 cm 3 , using the apparatus according to the invention is less than 10 minutes, and in particular only a few minutes. Preferred embodiments of the invention are defined in the subclaims. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in more detail with reference to the appended drawing, in which: FIG. 1 shows a diagrammatic, perspective view of a first embodiment of the ice cube apparatus according to the invention, with the surrounding housing having been omitted; FIG. 2 shows a view corresponding to FIG. 1 of a preferred embodiment of an ice cube apparatus in a freezing position; FIG. 3 shows a partial view of FIG. 2, in a release position; FIG. 4 shows a perspective view, with exploded components, of an ice cube tray with cylinder part and an insert element with piston part; and FIG. 5 shows a cross-sectional view through the assembled components from FIG. 4, in a release position. DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, for the sake of clarity the ice cube apparatus is illustrated without its surrounding housing. The surrounding housing can be shaped as desired with an appearance which, for example, fits in with other consumer electronics and/or kitchen equipment. The apparatus comprises a water reservoir 1 with a filling opening 3 . The filling opening 3 may preferably be closed off by a cover. The water reservoir 1 is connected to water-metering means, which in this case are formed by a pump unit. On the pump side, the pump unit is connected to a filler tube 5 which extends upwards from the bottom of the reservoir 1 and opens out into a metering unit 6 with four nozzles 7 . In the top of the apparatus, there is an ice cube tray 10 in which there are four mould cavities 11 which can be filled with water via the nozzles 7 at the start of a freezing cycle. On two opposite sides, the ice cube tray 10 is delimited by thermoelectric elements 15 , which in this case are formed by peltier elements. If the peltier elements are connected to a DC voltage source, depending on the current direction, heat will be extracted on one side of the peltier element and an amount of heat will be emitted on the other side. Consequently, the peltier element can act as a heat pump, by means of which it is possible to extract sufficient heat from the ice cube tray 10 for the water in the mould cavities 11 to freeze and form ice cubes. The various components of the apparatus are attached to a wall plate 19 , from which an electricity cable 20 also extends, which can be plugged into a wall socket in order to supply in particular the pump unit and the peltier elements with current. In the apparatus, there are control means 21 which comprise a timer unit for activating the various components of the apparatus in a defined order and for defined times. The two thermoelectric elements 15 , together with the ice cube tray 10 suspended between them, are arranged in such a way that they can rotate about a pivot pin 22 . The pivot pin 22 is connected to a drive 23 which is formed, for example, by an electric motor. The drive 23 is activated by the control means 21 and can ensure that the ice cube tray 10 is turned over at set times, so that the ice cubes which have formed in the mould cavities 11 fall out. A funnel-like collection container 25 is arranged beneath the ice cube tray 10 . The collection container 25 is preferably large enough to accommodate a number of ice cubes which corresponds to a full water reservoir 1 . On its underside, the collection container 25 is provided with a slide-out drawer 26 for the removal of ice cubes. In its base part, the drawer 26 is provided with one or more leakage openings allowing melt water to flow out. The leakage opening opens out above a leak bin 28 . Any melt water, and also water which is spilt during filling of the ice cube tray 10 automatically passes into the leak bin 28 , which can be removed from the apparatus and emptied or is provided, on its underside, with a closable outlet opening. The columnar arrangement of the leak bin 28 , the collection container 25 and the ice cube tray 10 has the further advantage that, in the event of a power failure, all the melt water which is released from ice cubes which have already been produced is collected in the leak bin 28 . The leak bin 28 advantageously ensures that ice cubes are only produced from fresh water. This is of benefit to the taste and, in addition, is hygienic. During use, the water reservoir 1 is filled with, for example, half a liter of tap water. Then, the apparatus can be switched on by pressing a switch 30 . The control means 21 will then begin by switching on the pump unit for a defined filling time, the filling time being precisely sufficient to fill the mould cavities 11 with water. The pump unit is switched off and the thermoelectric elements 15 are switched to a freezing position for a defined freezing time, in which they are supplied with current in such a manner that heat is extracted on the side of the ice cube tray 10 . The ice cube tray 10 is simultaneously cooled from two sides to below the freezing point in an efficient and very rapid way, with the result that the water in the mould cavities 11 freezes. During freezing, the heat which is released on those faces of the thermoelectric elements 15 which lie opposite the ice cube tray 10 has to be dissipated. For this purpose, these surfaces may be provided with cooling ribs. Furthermore, there is a fan 32 which, during freezing, releases a flow of air along the cooling ribs. The flow of air is discharged to the atmosphere via a grate in the surrounding housing. After the freezing time has elapsed, the current to the thermoelectric elements 15 is switched off for a defined release time. The heat which is then still stored in the cooling ribs flows back to the ice cube tray 10 , with the result that the outer layers of ice of the ice cubes melt and the ice cubes then rest freely inside the mould cavities 11 . In a variant, the current direction to the thermoelectric elements 15 is reversed, as a result of which these elements begin to emit heat on the side of the ice cube tray 10 . Then, the release means are activated, which in this embodiment means that the drive 23 turns over the ice cube tray 10 and empties it into the collection container 25 . A fresh freezing cycle can then begin. The ice cube tray 10 is returned to its original position, the mould cavities 11 are filled again with water, etc. The freezing cycle for freezing four ice cubes will continue to repeat itself automatically until either the water reservoir 1 is empty or the collection container 25 has been completely filled with ice cubes. The water reservoir 1 or the collection container 25 may to this end be fitted with suitable level detectors which emit a signal to the control means 21 . The water reservoir 1 is provided with a scale 35 which indicates the amount of water and the quantity of ice cubes which can be produced with this amount. The scale may also include an indication of the production time required. The amount of ice cubes to be produced can be determined by the user himself by filling the water reservoir 1 to a greater or lesser extent. The water reservoir 1 preferably has a volume of 0.1-1.5 liters, in particular 0.53-1.0 liter. This corresponds to the average requirement for ice cubes while ensuring that the apparatus remains compact and manageable. Operating on the basis of ice cubes with a volume of approximately 8 cm 3 , the apparatus has proven able to produce approximately 60 ice cubes within a period of approximately one hour. The freezing time required for the production of a series of four ice cubes, each with a volume of approximately 8 cm 3 , is less than ten minutes and in particular only a few minutes. The ice cubes produced are held at a temperature of approximately 0° C. in the collection container 25 . The collection container 25 can be insulated or supplied with cold derived from the thermoelectric elements 15 . As a result, the ice cubes produced can be stored for a certain time. The ice cube tray 10 is preferably made from aluminium, which is a good thermal conductor. To further minimize the production time and the amount of energy required, the ice cube tray 10 is designed to be as thin-walled as possible. In a particular embodiment, the mould cavities 11 of the ice cube tray 10 are lined with a layer of teflon, so that the ice cubes can be released from the mould cavities 11 more easily. In a variant embodiment which is not shown, the ice cube apparatus comprises an ice cube tray with a bottom which can be slid or tilted away and, with the aid of a suitable drive during a release operation, can be moved into an open position. The ice cubes can then fall freely downwards into a collection container arranged below. FIG. 2 shows a variant embodiment of the ice cube apparatus. In this FIG. too, the surrounding housing has been omitted for the sake of clarity. The apparatus comprises a water reservoir 40 with a filling funnel 41 and a pump unit 42 , which is connected to the reservoir and, via a filling tube 43 , is connected to an ice cube tray 45 with two mould cavities 46 . The ice cube tray 45 is delimited on two sides by two peltier elements 47 with cooling ribs 48 . Beneath the ice cube tray 45 there is a collection container 49 , which in this case is formed by an inclined chute which opens out into a closable dispensing opening. The ice cube tray 45 comprises an insert element 50 which can be moved up and down between a bottom position (FIG. 2) and a top position (FIG. 3 ). The insert element 50 comprises a lifting part which, in the bottom position, bears against the base of the mould cavity 44 . If, during a release operation after freezing, the insert element 50 is moved upwards into the top position, the lifting part pushes the ice cube upwards with it until ultimately it is tipped over the edge of the ice cube tray 45 and falls into the collection container 49 . The insert element 50 can be moved up and down using any suitable drive. Advantageously, however, water pressure from the pump unit 48 is used. In this case, it is even possible to fill the mould cavities 46 with water while the insert element 50 is moving upwards. In this way, the release of the ice cubes is combined with the operation of filling the mould cavities, which saves time and eliminates the need for a separate drive for the release means. The above release principle will be explained in more detail with reference to a variant of an ice cube tray with insert element which is shown in FIGS. 4 and 5. In FIGS. 4 and 5, the ice cube tray 60 is of cuboidal design and has a circular recess arranged in its base. A filler piece with a cylinder part 61 is arranged in the ice cube tray 60 from below. An insert element 62 is arranged above the top section of the cylinder part 61 , in such a way that it can slide up and down. The insert element 62 comprises a piston part 63 which rests inside the cylinder part 61 . The piston-cylinder system which is formed in this way can be connected, by means of a connection port 64 , to, for example, the filler tube 43 of the pump unit 42 of the ice cube apparatus shown in FIG. 2 . When the pump unit is set in operation, the water pressure built up ensures that the piston part 63 , together with the rest of the insert element 62 , is pushed upwards with respect to the cylinder part 61 and the ice cube tray 60 . The upwards travel can be limited by a stop pin 68 mounted in the piston part 63 or by the top side of the insert element 62 coming into contact with a spring means or stop wall. As can be seen in FIG. 5, the cylinder part 61 is provided on its top side with two inlet openings 65 which, in the top position of the insert element 62 , are opened by a narrowing 69 in the piston part 63 . From that moment, the water can flow into the mould cavities. When the mould cavities have been filled, the pump unit can be switched off, with the result that the water pressure drops and the insert element 62 can move back into its bottom position, for example under the influence of a spring means or the force of gravity. The insert element 62 has a vertical wall part 70 which forms a partition between the mould cavities in the ice cube tray 60 . In addition, the insert element 62 comprises two lifting parts 71 which extend on either side of the vertical wall part 70 . The two lifting parts 71 are inclined, ensuring that, in the top position of the insert element 62 , the two ice cubes are pushed outwards over the sides of the ice cube tray 60 . This is advantageous in particular if the assembly of ice cube tray 60 and insert element 62 is clamped between two thermoelectric elements, since the release direction can then be directed between the two thermoelectric elements. It is advantageously possible to make the lifting parts 71 and the vertical wall 70 of any desired shape. In this way, the final shape of the ice cubes is defined, so that they can be given an attractive appearance. Since, in addition, the insert element 70 is easy to exchange, the ice cube apparatus can easily and quickly be adapted to a desired shape of ice cube, for example with the logo of a hotel chain. The release principle illustrated in FIG. 2 may advantageously also be employed in FIG. 1, and vice versa, so that in this case too the fresh water is kept separate from water which has already been used or used water is returned to the water reservoir for reuse. Consequently, the invention provides an ice cube apparatus which operates simply, quickly and effectively and is of acceptably small size, making the apparatus very suitable for use as a stand-alone unit in, for example, a home or a hotel room. In addition to the embodiments shown, numerous variants are conceivable. For example, the water reservoir may be arranged removably in the housing, so that it can be taken out of the apparatus and filled beneath a tap. It is also possible for the collection container to be fitted removably. To collect melt water, a separate leak bin may be provided beneath the removal means. Keeping the melt water outside the water reservoir in this way advantageously ensures that only fresh water is used to make the ice cubes.

Ice cube apparatus for the production of ice cubes, comprising a water reservoir with a filling opening, which can be filled with a desired amount of water, an ice cube tray, which is separate from the water reservoir and has at least one mold cavity, water-metering means for supplying a metered amount of water from the water reservoir to the mold cavity, at least one thermoelectric element for freezing the amount of water in the mold cavity, control means with a timer unit for providing current to the thermoelectric element for a defined freezing time, in such a manner that this element extracts heat on the side of the ice cube tray, release means for releasing a frozen ice cube from the ice cube tray after the freezing time, and discharge means for collecting and dicharging the ice cube which has been released from the ice cube tray.

[0001] This application is a continuation-in-part of and claims priority of prior pending application Ser. No. 09/609082, entitled “Floor Vinyl Repair Technique And Tool” filed Jun. 30, 2000, issuing as U.S. Pat. No. 6,619,360 on Sep. 16, 2003, which is incorporated herein by this reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates generally to flooring and more specifically to repairs for damaged vinyl floors. [0004] 2. Related Art [0005] Vinyl as a flooring material has become very popular. Many millions of square feet of vinyl flooring are installed every year. Often, after or during installation, the vinyl flooring is damaged by dents, holes, scrapes or scratches. Then, the vinyl flooring needs to be repaired. [0006] Typically, the repair of this damage to vinyl flooring is done by: [0007] Providing an oversized replacement patch that matches the pattern in the damaged area (for example, by cutting from a roll or large sample of the vinyl); [0008] Aligning the patch and taping it in place; [0009] Cutting through both layers with a utility knife along a cutting line determined to surround and not cut through the damaged area; [0010] Removing the patch and peeling up the damaged flooring with a scraper, taking care not to damage the cut edges, and using a heat gun or iron to soften the adhesive, if necessary; [0011] Applying new flooring adhesive to the newly-cut patch and pressing it in place into the opening created by cutting the damaged flooring from the undamaged vinyl; and [0012] Wiping off any excess adhesive with a damp cloth and covering the patch with a weight for 24 hours. [0013] Preferably, the cut is made along the flooring pattern lines, if any, to make the repair less visible. If it is discovered that the section to be removed isn't attached to the subfloor by adhesive, an attempt to slip some new adhesive underneath the exposed edges of the original vinyl to keep it in place is recommended. [0014] However, whenever this prior art repair technique is practiced, the seam (between the original vinyl and the replaced, repair piece) is noticeable. The seam may be barely noticeable, but it is there nonetheless, and irritating to discriminating homeowners and floor repairmen. The reason for the seam is because typically the cut replacement piece turns out to be slightly smaller than the original damaged piece. Typically, the industry craftsmen have filled this seam with seam sealer or filler. However, it has been a desire in the industry to eliminate this seam space as much as possible. [0015] This imperfect fit may be because the top piece of vinyl is stretched slightly when it is cut with the knife while overlaying the relative soft damaged piece. The damaged piece, on the other hand, is constrained by the supporting floor and is totally and/or substantially bound by an underlying adhesive, so it does not stretch, or stretches less, when cut. After the cut is performed, the replacement piece tends to be slightly smaller than the original damaged piece, leaving a slight seam between the original, undamaged vinyl and the inserted replacement piece. [0016] Alternatively, the imperfect fit may be because, when the semi-elastic replacement patch is cut out from the oversized patch sheet, the replacement patch may tend to contract slightly, that is, the edges of the replacement patch pull inward slightly, which results in a slightly smaller replacement patch than originally intended. Also, when the semi-elastic vinyl material on the floor is cut, the edges around the cut-out damaged piece may tend to contract slightly especially if not totally secured to the floor by adhesive, that is, the edges of vinyl surrounding and defining the opening pulling-back slightly. This would tend to increase the size of the opening in the floor vinyl into which the replacement patch will be placed. Therefore, either the edges of the replacement patch, the edges of the remaining original vinyl, or both, may have retracted in opposite directions, resulting in a small gap between the edges that must be filled and/or hidden. [0017] Thus, whether the imperfect fit occurs due to stretching and subsequent retraction, and/or contraction of edges after they are cut from adjacent vinyl material, the imperfect fit may be attributed to retraction or contraction of the vinyl. [0018] The present invention addresses the need for a closer fit between the inserted replacement vinyl patch piece and the surrounding, original undamaged vinyl, preferably by adapting the method and apparatus for cutting the vinyl patch. SUMMARY OF THE INVENTION [0019] The present invention is a floor vinyl repair technique and tool. According to the present invention, the prior art repair technique is practiced, except a specially-adapted spacer is placed between the patch and the damaged area prior to taping the oversized replacement patch in place atop the damaged section in preparation for cutting through both layers with the knife. Typically, the spacer is placed or pressed firmly against/into the damaged section generally at, or near, the middle of this section, before the oversized replacement patch is placed above the damaged area. This way, when the patch is taped in place, the center of the patch is slightly elevated above the damaged piece. This slight elevation allows for a slight increase in the perimeter of the patch, or, in other words, a slight increase in the total area of the replacement piece once it is cut. This increase in the perimeter dimension(s)/area of the cut replacement patch offsets the retraction (in opposite directions) of the patch and original vinyl flooring that is believed to occur after both layers of material are cut with the knife. As a result, a more exact fit between the patch and the surrounding, original undamaged vinyl may be achieved when the patch is installed. [0020] Typically, the amount of original vinyl to be removed and, correspondingly, the size of the replacement patch, is determined by the size and shape of the dent, hole or surface abrasion to be repaired. Preferably, a sufficient amount of vinyl is removed so that no significant distortion of the original pattern or texture is noticeable. By trial and error and experience, we have determined an estimated relationship between the size of the spacer to be inserted between the two layers of vinyl before the cut, and the size of the replacement patch. BRIEF DESCRIPTION OF THE DRAWINGS [0021] [0021]FIG. 1 is a perspective view of the prior art vinyl flooring repair technique. [0022] [0022]FIG. 2 is a perspective view of one embodiment of the vinyl flooring repair technique according to the present invention. [0023] [0023]FIG. 3A is a top perspective view of one embodiment of the repair tool insert/spacer according to the present invention. [0024] [0024]FIG. 3B is a side cross-sectional view of the embodiment of FIG. 3A. [0025] [0025]FIG. 4 is a side-cross-sectional view along line 4 - 4 in FIG. 2. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0026] Referring to the Figures, there is shown in FIG. 1 the prior art vinyl flooring repair technique described in the Related Art section above. In FIGS. 2 - 4 , there are depicted several, but not all, embodiments of the present invention. [0027] According to FIG. 1, oversized patch 10 is laid over damaged vinyl section 12 so that patch 10 extends over the surrounding, original undamaged vinyl 14 . The oversized patch 10 is aligned to match the pattern on damaged section and the adjacent undamaged vinyl, and is taped into place with tape strips 16 , 16 ′ and 16 ″. Then, both layers of vinyl (oversized patch 10 and damaged section 12 ) are cut with utility knife 18 , for example, along the dashed lines shown in FIG. 1 to form replacement patch 15 and opening 17 in the floor vinyl. The oversized patch 10 is then removed, including the newly-cut replacement patch 15 that has been cut out generally from the center of the oversized patch 10 . The damaged section 12 is peeled up off the floor with a scraper (not shown). Then, new adhesive is applied to the newly-cut replacement patch 15 and the patch 15 is pressed into place in the opening 17 where the damaged section 12 was removed. Any excess adhesive is removed with a damp cloth, and this replacement patch 15 is covered with a weight for about 24 hours to hold it in place while the adhesive dries. [0028] In FIG. 2 depicts the vinyl floor repairing technique according to the present invention. In the invented technique, the steps of the prior art repair technique are practiced, except that a specially-adapted spacer 20 is placed on top of the damaged section 12 prior to positioning the oversized replacement patch 10 over the damaged section 12 and taping or otherwise securing it in place. As a result, the oversized replacement patch is elevated slightly above the damaged piece prior to cutting through both layers with the knife. During cutting, this slight elevation increases the perimeter of the newly-cut patch to offset contraction/retraction of the patch and/or of the original vinyl sheet that may happen after the cut(s) are made. [0029] Preferably, the spacer 20 is placed in the center of the damaged section that will be cut out, which may or may not correspond to the center of the damage in the vinyl, that is, the hole/cut/gouge/scrape in the vinyl. By placing the spacer 20 in the middle of the section that will be cut out, it is more likely that the spacer will evenly and accurately raise the oversized patch in a manner that will consistently increase the perimeter of the replacement patch 15 an appropriate and equal amount all around the patch 15 . For example, if the damage comprises a hole in the vinyl, the repairman may choose to cut out a larger area in which the hole is slightly to one side of that area, so that the spacer may be placed/pressed into the damaged vinyl in the center of the area to be cut out but not in the center of the hole. [0030] Increasing the perimeter dimension(s) and total area of the replacement patch, via spacer insertion prior to cutting, serves to counteract the retraction/contraction of the vinyl material encountered after the sections are cut. Larger replacement patches may have a tendency to retract/contract more than smaller patches and the migration of the edges of the original vinyl may also be greater for larger removed sections. Further, a larger patch should be raised up in its center more than a smaller patch, in order to obtain an appropriate amount/percentage of perimeter/area increase. Consequently, depending upon the size of the patch, preferably different sized spacers may be used. A combination thickness and radius or size of the domed-disc spacer may be important. For example, the inventors have determined that, for replacing a damaged section about 3 to 5 inches square, a domed-disc about ⅛″ high at the center and about ⅞″ square (disc # 1 ) is preferably used. Table 1 offers a rough guide for repairing damaged square sections. TABLE 1 Size of Square Size of Disc  3 to 5″ 1/8″ high × 7/8″ (disc #1)  5 to 8″ 3/16″ high × 1 1/2″ (disc #2)  8 to 11″ stack disc #1 on top of disc #2 11 to 18″ 5/16″ high × 2 3/4″ (disc #3) 18 to 24″ stack disc #2 on top of disc #3 24″ and up stack disc #1 on top of disc #2, and disc #2 on top of disc #3 [0031] The spacer/insert may be various shapes that conveniently take up space between oversized patch 10 and damaged section 12 . A squared-off domed-disc is preferred, as illustrated in FIGS. 3A and 3B, because the square shape helps align the disc in the center of damaged section 12 , which is usually cut out as a square or rectangular shape. The inventors prefer the domed-disc because the patch 10 slides easily over the dome when aligning it with the pattern in the original, undamaged vinyl 14 . A square, domed-disc spacer is also preferred, as the dome shape tends to raise all regions of the replacement patch an approximately equal amount and, hence, to increase the perimeter of the patch an approximately equal amount all the way around the patch. Other shapes may be used, with those having a central region 26 raised relative to their edges 28 being preferred. For example, in FIG. 3B, one may see that the square, domed spacer includes a central region 26 having a thickness from top to bottom that is greater than the thickness of the spacer at the edge regions 28 . [0032] Preferably, the spacer 20 has a pointed tip or other gripper(s) on its underside, so that it may be firmly pressed into the damaged vinyl to retain it in place during the cutting procedure. Preferably, a pointed tip 22 is provided on the bottom of the domed-disc to better engage the damaged section 12 once the disc is centered. Other gripping member(s) may be used to keep the spacer in place. [0033] The preferred pointed tip is of a small enough diameter, short enough length, and sharp enough distal end that it easily “pokes” into the damaged vinyl without a great deal of effort by the user and without extending through the damaged vinyl into the floor underneath the vinyl. For example, the preferred pointed tip is a short, sharp protrusion that has a length L of less than about {fraction (1/10)} of the width W of the spacer. [0034] Also, preferably, a depression 24 is provided on the top center of each domed-disc for receiving the pointed tip of another spacer. This enables several of the discs to be stacked for use and for storage, by virtue of the pointed tip of an upper spacer fitting into the depression of the lower spacer. While the preferred depression 24 is conical, a depression more closely fitting the point tip 22 is also acceptable, for example. [0035] While the invented methods and apparatus are specially-adapted for vinyl flooring, the inventors envision that other flooring coverings may also benefit from the invention. For example, the methods and apparatus may be beneficial to other sheet floor coverings, especially to those that are semi-elastic or partially elastic. [0036] Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.

A floor covering repair technique and tool includes placement of a spacer between a patch and a damaged floor covering piece before cutting through both layers. This way, the replacement patch is elevated slightly above the damaged piece and this slight elevation allows for a slight increase in the perimeter/total area of the patch, which offsets the slight retraction/contraction of the edges of the patch and/or the edges of the original flooring after the cut. This results in a more exact fit between the patch and the surrounding, original undamaged when the patch is installed.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a National Stage Entry application of PCT Application No. PCT/JP2012/072245, filed Aug. 31, 2012. BACKGROUND Disclosed herein a seat frame for a vehicle seat, and more particularly, a seat frame for a vehicle seat including side frames arranged on both right and left ends of a seat back frame, and a connection frame for connecting bottom ends of the side frames with each other. In a seat frame for a vehicle seat, side frames are arranged on both ends of a seat back frame constructing a frame of a seat back, and bottom ends of the side frames are usually connected with each other by a connection frame. Moreover, among prior-art side frames, there is such a side frame that an upper portion and a lower portion are independent members, and both portions are joined by welding or the like. For this side frame constructed by the two components, the connection frame is provided to connect the members forming the lower portions with each other (for example, refer to Japanese Patent Document No. 2008-201216 A (“the '216 Document”). On the other hand, when the welding is used to assemble the seat frame, the number of times of welding decreases as the number of the components of the seat frame decreases, which is preferred in terms of workability of the frame assembly. Therefore, in a vehicle seat according to Japanese Patent Document No. 2012-126245 A (“the '245 Document”), each of side frames arranged at right and left sides is constructed by a single member, and the side frames are connected with each other by welding a lower frame, which is the connection frame, to bottom ends of the respective side frames, thereby connecting the side frames with each other. A description is now given of a frame structure of the vehicle seat according to the '245 Document, and the lower frame is constructed by a metal plate member extending as a straight line, and both ends on an extension direction of the lower frame are welded to rear surface flanges extending from rear surface edges of the side frames toward a seat inside. As a result, the side frames are connected with each other by the lower frame, and a rigidity of each of the side frames, particularly, a rigidity of the bottom end of each of the side frames is secured. A rigidity of each of the side frames needs to be further increased, and particularly, a rigidity against such a load as to bend the side frame toward the inside of the seat needs to be secured. In other words, if the bottom ends of the side frames are connected by the connection frame to increase the rigidity, the connection frame needs to be attached to secure such a degree of rigidity to suppress the inward bends of the side frames. Further, when the connection frame is attached to the side frames, the connection frame needs to be attached to further increase the rigidity while interference with members around attached locations are avoided. Moreover, if the connection frame is attached to the side frames by way of welding, welded areas between the connection frame and the side frames need to be set to promote a welding operation. Various embodiments of the present invention consider the foregoing problems, and an object of the embodiments is to provide a seat frame for a vehicle seat particularly realizing a structure capable of increasing the rigidity to such a degree as to suppress the inward bends of the side frames in the configuration in which the bottom ends of the side frames are connected by the connection frame. Moreover, another object is to provide a seat frame for a vehicle seat realizing a structure capable of further increasing the rigidity while the interference with the members around the attached locations are avoided when the connection frame is attached to the side frames. Moreover, still another purpose is to provide a seat frame for a vehicle seat in which welded areas between the connection frame and the side frames are set to promote the welding operation in the structure in which the connection frame is welded to the side frames. The above-described problems may be solved by a seat frame for a vehicle seat including side frames arranged on both ends in a widthwise direction of the vehicle seat in a seat back frame provided for a seat back of a vehicle seat, the side frames each comprising a bottom end, and a connection frame for connecting the bottom ends of the side frames, which are attached to a seat cushion of the vehicle seat, with each other, where each of the side frames further includes a side wall arranged outside in the widthwise direction in the side frame, and extending in a top to bottom direction, and a rear wall extending inward from the side wall in the widthwise direction, the connection frame includes first extension portion extending along the widthwise direction, and second extension portions extending forward respectively from both ends in the widthwise direction of the first extension portion, and each of the second extension portions is located inside the side wall in the widthwise direction, and overlaps with the side wall. When the connection frame is attached to the respective side frames in the seat frame for the vehicle seat, each of the second extension portions, which is a portion of the connection frame, is arranged inside the side wall of the side frame in such a state that each of the second extension portions overlaps with the side wall. This configuration increases the rigidity of the side walls of the side frames, particularly a rigidity against a load acting in the widthwise direction of the vehicle seat, and the inward bends of the side frames are suppressed. In other words, the rigidity can be increased to such a degree as to suppress the inward bends of the side frames in the above-mentioned seat frame for the vehicle seat. Moreover, the above-mentioned seat frame of the vehicle seat preferably includes a reclining mechanism for swinging the seat back with respect to the seat cushion, where the reclining mechanism is attached to an outside surface located outside in the widthwise direction out of side surfaces of the side wall, the second extension portion abuts against an inside surface located on a rear side of the outside surface in the widthwise direction out of the side surfaces of the side wall, and an area of the side wall of which the second extension portion abuts against the inside surface deviates from an area of which the reclining mechanism is attached to the outside surface. Welding marks for attaching the reclining mechanism and the like exist on the inside surface of the portion to which the reclining mechanism is attached on the side wall of the side frame, and some recesses and protrusions are thus formed. In the above-mentioned configuration, the connection frame is attached to avoid the portion where the recesses and protrusions are formed by the welding on the inside surface of the side wall of the side frame, and the connection frame can thus be satisfactorily attached. Moreover, in the above-mentioned seat frame of the vehicle seat, preferably, the area of the side wall of which the reclining mechanism is attached to the outside surface is a circular area viewed in the widthwise direction, and at least a portion of the second extension portion extends in an arc shape along an outer edge of the circular area. The above-mentioned configuration promotes an operation of attaching the connection frame to avoid the portion to which the reclining mechanism is attached on the side wall of each of the side frames. Moreover, in the above-mentioned seat frame of the vehicle seat, more preferably, a swing shaft for the swing of the seat back by the reclining mechanism with respect to the seat cushion is provided in such a state as to pass through the side walls in the widthwise direction, and at least a portion of the second extension portion extends in an arc shape to go around from a rear of the swing shaft to a front thereof. When the connection frame is attached while avoiding the portion to which the reclining mechanism is attached on the side wall of each of the side frames, the above-mentioned configuration enables the attachment of the connection frame to the side walls of the side frames in such a state that the interference with the swing shaft is avoided when the seat back swings with respect to the seat cushion. Moreover, the connection frame extends in the arc shape to go around from the rear of the swing shaft to the front thereof, and the area in which the portion of the side wall of each of the side frames overlaps with the connection frame is thus somewhat longer in the front to back direction. As a result, the portion increased in the rigidity by the attachment of the connection frame out of the side wall of each of the side frames is provided to extend in the front to back direction of the vehicle seat. As a result, the rigidity of the side frame against the load acting in the widthwise direction of the vehicle seat further increases. Moreover, in the above-mentioned seat frame of the vehicle seat, further preferably, a side wall side bent portion bending toward the inside in the widthwise direction is formed on a bottom end of the side wall, a second extension portion side bent portion bending toward the inside in the widthwise direction is formed on a bottom end of the second extension portion, and at least a portion of the second extension portion extends so that the second extension portion side bent portion aligns with the side wall side bent portion, and a portion of the second extension portion side bent portion overlaps with the side wall side bent portion. In the above-mentioned configuration, a unity of the bottom end of the side wall of each of the side frames and the connection frame is enhanced, resulting in a further increase in the rigidity in the bottom end of the side wall of each of the side frames. Moreover, in the above-mentioned seat frame of the vehicle seat, at least a portion of the area of the side wall of which the second extension portion abuts against the inside surface may be located above the area of which the reclining mechanism is attached to the outside surface, and a bent portion bending toward the inside in the widthwise direction is formed on a top end of the second extension portion. In the above-mentioned configuration, the connection frame can be attached to avoid the portion to which the reclining mechanism is attached on the side wall of each of the side frames, and the rigidity of the connection frame itself simultaneously increases, which increases the rigidity of the side frames. Moreover, in the above-mentioned seat frame of the vehicle seat, preferably, the area of the side wall of which the reclining mechanism is attached to the outside surface is a circular area viewed in the widthwise direction, the area of the side wall of which the second extension portion abuts against the inside surface is an area in a C shape along the outer edge of the circular area viewed in the widthwise direction, and the second extension portion includes an upper portion arranged above the circular area and a lower portion arranged below the circular area. In the above-mentioned configuration, while the portion to which the reclining mechanism is attached on the side wall of each of the side frames is avoided, the connection frame can be attached to the side frames to further increase the rigidity. Moreover, in the above-mentioned seat frame of the vehicle seat, more preferably, a swing shaft for the swing of the seat back by the reclining mechanism with respect to the seat cushion is provided in such a state as to pass through between the side walls in the widthwise direction, the upper portion and the lower portion are respectively welded to the side wall, a welded area between the upper portion and the side wall extends in a front to back direction of the vehicle seat so that at least a portion of the welded area is located in front of the swing shaft, and a welded area between the lower portion and the side wall extends in the front to back direction so that at least a portion of the welded area is located in the rear of the swing shaft. In the above-mentioned configuration, the respective upper portion and lower portion of the second extension portion of the connection frame can be satisfactorily fixed to the side wall of each of the side frames. Further, each of the welded areas extends in the front to back direction of the vehicle seat, a strength against a load acting in the front to back direction can be secured, and the state in which the upper portion and the lower portion of the second extension portion are respectively fixed to the side wall of each of the side frames can be stably maintained. Moreover, in the above-mentioned seat frame of the vehicle seat, a bottom end of the first extension portion at a center may be located further up than the bottom ends of the first extension portion at both ends in the widthwise direction in the connection frame provided for the vehicle seat which is a front seat arranged in front of a rear seat. The feet of a passenger on the rear seat may enter into a space located below the connection frame of the front seat. If the bottom end at the center in the extension direction is located above the bottom ends of the ends in the extension direction in the first extension portion located above the feet of the passenger out of the connection frame, an interference of the feet of the passenger with the connection frame can be suppressed. In the seat frame for the vehicle seat according to an embodiment, each of the second extension portions of the connection frame is arranged inside the side wall of the side frame in such a state that the second extension portion overlaps with the side wall, the rigidity of the side frame against the load acting in the widthwise direction of the vehicle seat thus increases, and the inward bend of the side frame is suppressed. In the seat frame for the vehicle seat according to an embodiment, some recesses and protrusions are formed on the inside surface of the portion to which the reclining mechanism is attached on the side wall of the side frame, and the connection frame can be satisfactorily attached by attaching the connection frame to avoid the portion. In the seat frame for the vehicle seat according to an embodiment, the operation of attaching the connection frame to avoid the portion to which the reclining mechanism is attached on the side wall of each of the side frames is promoted. In the seat frame for the vehicle seat according to an embodiment, the connection frame can be attached to the side walls of the side frames in a state in which the interference with the swing shaft is avoided. Further, the portion increased in the rigidity by the attachment of the connection frame out of the side wall of each of the side frames is provided to extend in the front to back direction of the vehicle seat, and as a result, the rigidity of the side frames against the load acting in the widthwise direction of the vehicle seat further increases. In the seat frame for the vehicle seat according to an embodiment, the unity of the bottom end of the side wall of each of the side frames and the connection frame is enhanced, resulting in a further increase in the rigidity in the bottom end of the side wall of each of the side frames. In the seat frame for the vehicle seat according to an embodiment, the connection frame can be attached to avoid the portion to which the reclining mechanism is attached on the side wall of each of the side frames, and the rigidity of the connection frame itself simultaneously increases, which increases the rigidity of the side frames. In the seat frame for the vehicle seat according to an embodiment, while the portion to which the reclining mechanism is attached on the side wall of each of the side frames is avoided, the connection frame can be attached to the side frames to further increase the rigidity. In the seat frame for the vehicle seat according to an embodiment, the connection frame can be satisfactorily fixed to the side wall of each of the side frames, the strength against the load acting in the front to back direction can be secured, and the state in which the connection frame is fixed to the side wall of each of the side frames can be stably maintained. In the seat frame for the vehicle seat according to an embodiment, the interference of the feet of the passenger on the rear seat with the connection frame can be suppressed, when the feet of the passenger on the rear seat enter into the space located below the connection frame of the front seat. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view showing an exterior of a vehicle seat according to an embodiment of the present invention; FIG. 2 is a perspective view showing an entire seat frame of the vehicle seat according to the embodiment of the present invention; FIG. 3 is a rear view showing the seat frame of the vehicle seat according to the embodiment of the present invention; FIG. 4 is an exploded perspective view of a neighborhood of a side frame out of the seat frame; FIG. 5 is a front view showing a positional relationship among the side frame, a connection frame, and a reclining mechanism; FIG. 6 is a perspective view showing a connection state between the side frame and the connection frame; FIG. 7 is an explanatory side view of welded locations between the side frame and the connection frame; FIG. 8 is a cross sectional view showing a structure of the side frame made on a plane and in a direction indicated by A-A in FIG. 3 ; and FIG. 9 is a cross sectional view of the connection frame attached to the side frame made on a plane and in a direction indicated by B-B in FIG. 3 . DETAILED DESCRIPTION Hereinafter, a description is given of a seat frame for a vehicle seat according to various embodiments of the present invention referring to FIGS. 1 to 9 . A height adjustment mechanism 4 and a slide rail mechanism R described later are not shown in FIG. 2 for the sake of clarity. Hereinafter, a front to back direction is a direction matching a travel direction of the vehicle. Moreover, a widthwise direction is a direction along a lateral width of the vehicle, more specifically in a right to left direction, and corresponds to a widthwise direction of the vehicle seat. Moreover, a top to bottom direction is a top to bottom direction of the vehicle seat. A description given of positions and attitudes of respective portions of the seat in a normal state, in other words, a state in which a passenger is seated hereinafter unless otherwise specified. First, a description is given of a basic configuration of the vehicle seat and the seat frame (hereinafter referred to as this seat S and this frame F) according to an embodiment of the present invention. This seat S is approximately the same in a basic structure as a publicly known vehicle seat, and is used as a front seat arranged in front of a rear seat particularly in this embodiment. This seat S is not limited to the front seat, and the present invention can be applied to a seat frame for a vehicle seat, which is a rear seat. More specifically, this seat S includes a seat back S 1 , a seat cushion S 2 , and a headrest S 3 as main components as shown in FIG. 1 . On the other hand, this frame F constructing a framework of this seat S includes a seat back frame F 1 provided for the seat back S 1 , and a seat cushion frame F 2 provided for the seat cushion S 2 as shown in FIG. 2 . Moreover, guide stays fs for supporting the headrest S 3 body when pillars S 3 a extending from a bottom of the headrest S 3 are inserted into them are fixed to a top of the seat back frame F 1 . Moreover, most of portions of this frame F are constructed by metal members. The assembled seat back frame F 1 and the seat cushion frame F 2 are constructed to respectively form rectangular frames as shown in FIG. 2 . Then, bottom ends of side frames 11 provided on both ends in the widthwise direction of the seat back frame F 1 are assembled to rear ends of side portion frames 1 provided on both ends in the widthwise direction of the seat cushion frame F 2 . The bottom end of the side frame 11 is assembled through a reclining mechanism 3 shown in FIG. 4 to the rear end of the side portion frame 1 in this frame F. The reclining mechanism 3 is activated by an operation of a passenger on an operation portion, not shown, and is configured to swing the seat back S 1 forward or backward with respect to the seat cushion S 2 . The reclining mechanisms 3 are individually provided for the respective side frames 11 provided as a left-and-right pair, and are attached to bottoms of outside surfaces 12 a of the respective side frames 11 in this seat S. Moreover, the reclining mechanisms 3 are welded to rear ends of inner wall surfaces of the side portion frames 1 opposite to the sides welded to the side frames 11 . A structure of each of the reclining mechanisms 3 is a known mechanism, and includes reclining mechanism bodies 3 a , and a penetration shaft 3 b extending in the widthwise direction in such a state as to pass through the reclining mechanism bodies 3 a . Then, a drive mechanism which is provided in the body, and is not shown, is activated by a rotation of the penetration shaft 3 b . As a result of the activation of the drive mechanism, a portion joined to the side frame 11 side out of the reclining mechanism 3 a relatively swings about the penetration shaft 3 b with respect to a portion on the opposite side thereof, specifically a portion joined to the side portion frame 1 side of the seat cushion frame F 2 . As a result, the side frame 11 relatively swings about the penetration shaft 3 b with respect to the seat cushion S 2 . In other words, the seat back S 1 swings about the penetration shaft 3 b with respect to the seat cushion S 2 . The penetration shaft 3 b is a rotational shaft for rotating to drive the reclining mechanisms 3 , and is also a swing shaft when the seat back S 1 swings with respect to the seat cushion S 2 by the reclining mechanisms 3 . The penetration shaft 3 b is a shaft shared between the reclining mechanism 3 attached to the one side frame 11 and the reclining mechanism 3 attached to the other side frame 11 in this seat S. In other words, the penetration shaft 3 b passes through the side wall 12 of the one side frame 11 , extends toward the other side frame 11 along the widthwise direction, and further penetrates the side wall 12 of this side frame 11 . Then, each of both ends of the penetration shaft 3 b passes through the corresponding reclining mechanism body 3 a , and further passes through to the side portion frame 1 of the seat cushion frame F 2 located by the reclining mechanism body 3 a as shown in FIG. 5 . In other words, the penetration shaft 3 b is provided for rotation in such a state as to penetrate through the side walls 12 of the side frames 11 and the side portion frames 1 in the widthwise direction in this seat S. The penetration shaft 3 b may be rotated through an operation portion such as a lever by the passenger, or may be rotated by a power generated by a drive device such as an actuator or the like. On the other hand, the slide rail mechanism R for sliding this seat S in the front to back direction with respect to a vehicle body floor is arranged at a position below the seat cushion S 2 . Then, a height adjustment mechanism 4 for adjusting a seat height is provided between the seat cushion S 2 and the slide rail mechanism R in the top to bottom direction in this seat S. This height adjustment mechanism 4 is activated by the passenger operating the operation lever 5 shown in FIG. 1 . Specifically, the height adjustment mechanism 4 uses a drive force generated by the operation on the operation lever 5 to turn turn links 6 for connecting between the seat cushion frame F 2 and the slide rail mechanism R, thereby adjusting the seat height. More specifically, a total of four turn links 6 are provided to be located at both ends in the widthwise direction respectively at a front end and a rear end of the seat cushion frame F 2 . One end of each of the turn links 6 is turnably supported by a support portion Rx provided on an upper rail Ru of the slide rail mechanism R to protrude upward. Moreover, the other end of each of the turn links 6 is turnably attached to the side portion frame 1 of the seat cushion frame F 2 . On the other hand, a sector gear 7 a is formed on the rear turn link 6 located on one end side in the widthwise direction out of the turn links 6 , and a pinion gear 7 b meshes with the sector gear 7 a . The pinion gear 7 b is connected to the operation lever 5 through a connection shaft, which is not shown. As a result, when the operation lever 5 is operated, the pinion gear 7 b rotates integrally with the connection shaft, and a meshing position between the pinion gear 7 b and the sector gear 7 a changes. As a result, the turn link 6 on which the sector gear 7 a is formed turns, and the other turn links 6 turn in a form of following this turn link 6 . As a result, the seat body including the seat cushion S 2 rises and falls, resulting in adjustment of the seat height. A detailed description is now given of the seat back frame F 1 out of this frame F. The seat back frame F 1 includes the side frames 11 arranged at both ends in the widthwise direction, an upper frame 21 for connecting top ends of the side frames 11 with each other, and a lower member frame 31 serving as a connection frame for connecting the bottom ends of the side frames 11 as shown in FIGS. 2 and 3 . The upper frame 21 is a portion forming a top end of the seat back frame F 1 as shown in FIGS. 2 and 3 . The upper frame 21 is constructed by a bent portion 22 including both ends bent in a downward U shape to direct downward and an upper member frame 23 bridging between one end and the other end of the bent portion 22 . The side frames 11 form both ends of the seat back frame F 1 in the widthwise direction, and are portions extending from the top to bottom direction. Each side frame 11 is bent in an approximately arcuate shape so that a top end thereof is located somewhat in the rear of a bottom end in this seat S as shown in FIG. 2 . Moreover, each side frame 11 is formed from a single member, and is specifically formed by machining a single metal plate in this seat S. A more detailed description is given of the structure of each side frame 11 . The side frames 11 arranged at the both ends in the widthwise direction have left-right symmetry structures, and a description is given of only the structure on the one side frame 11 hereinafter. Each side frame 11 includes the side wall 12 located on the outside in the widthwise direction, and a rear wall 13 extending from a rear end of the side wall 12 inward in the widthwise direction as shown in FIG. 8 . The side wall 12 extends approximately straight in the top to bottom direction, a top end is in such a pointed shape as to narrow upward viewed from the side in the widthwise direction, a center has a gently curved shape, and a bottom has a semi-ellipsoidal shape. Multiple holes are formed on the side wall 12 , a hole 12 c out thereof is formed at the bottom end of the side wall 12 , and the penetration shaft 3 b for driving the reclining mechanisms 3 is inserted into this hole. Further, one of the remaining holes is a hole for fixing the side frame 11 when the seat back frame F 1 is assembled, particularly when members constructing the seat back frame F 1 are assembled to each other, and a fixing jig, which is not shown, is inserted for the assembly into this hole. Moreover, the reclining mechanism 3 is attached to the outside surface 12 a located on the outside in the widthwise direction out of side surfaces of the side wall 12 as described before. More specifically, the reclining mechanism 3 is attached at a portion located somewhat above the bottom end of the side wall 12 by way of the laser welding in this seat S. When the reclining mechanism 3 is attached to the outside surface 12 a of the side wall 12 by way of the laser welding, a laser irradiates on the inside surface 12 b located on the rear side of the outside surface 12 a in the widthwise direction out of the side surfaces of the side wall 12 . Therefore, recesses and protrusions are formed as welding marks on the inside surface 12 b. A portion out of the reclining mechanism 3 joined to the side wall 12 of the side frame 11 , more specifically, a portion of the reclining mechanism body 3 a opposing the side wall 12 is circular in this seat S. Thus, an area of which the reclining mechanism 3 is attached to the outside surface 12 a on the side wall 12 of each side frame 11 is a circular area M viewed in the widthwise direction as shown in FIG. 7 in this seat S. The hole into which the penetration shaft 3 b is inserted is formed at a center position of the circular area M. Moreover, a side wall side flange 14 bent inward in the widthwise direction is formed at a front end of the side wall 12 as shown in FIGS. 4 and 8 . This side wall side flange 14 corresponds to a side wall side bent portion, and is provided from the top end to the bottom end of the side wall 12 in order to reinforce the side wall 12 . The bottom end of the side wall 12 has a semicircular shape as described before, and the side wall side flange 14 provided at the bottom end of the side wall 12 is formed in the arc shape to go around from the front to the rear along an outer edge of the bottom end of the side wall 12 . The rear wall 13 is adjacent to a rear end of the side wall 12 in such a state as to cross the side wall 12 , and an angle between the rear wall 13 and the side wall 12 is approximately 90 degrees in this seat S. In other words, an outside end in the widthwise direction of the rear wall 13 forms a corner of the side frame 11 along with the rear end of the side wall 12 . Moreover, a top end of the rear wall 13 is at a position somewhat lower than the top end of the side wall 12 , and a bottom end of the rear wall 13 is somewhat higher than the bottom end of the side wall 12 . Then, a member frame attachment portion 13 a in an approximately trapezoidal shape larger in an inward extension amount in the widthwise direction than a portion located above this portion is formed at the bottom end of the rear wall 13 as shown in FIG. 3 . A lower member frame 31 described later is attached to this member frame attachment portion 13 a. Further, a rear wall side flange 15 bent forward is formed at an inside end in the widthwise direction of the rear wall 13 as shown in FIGS. 4 and 8 . The rear wall side flange 15 is formed from the top end to the bottom end of the rear wall 13 in order to reinforce the rear wall 13 , and extends to the top end of the member frame attachment portion 13 a . Moreover, the rear wall side flange 15 is similarly formed in an area located below the main frame attachment portion 13 a out of the rear wall 13 . On the other hand, the flange 15 is not formed on a portion inside the widthwise direction and a portion on a bottom end side out of an outer edge portion of the member frame attachment portion 13 a in order to avoid interference with the lower member frame 31 . The rear wall side flange 15 formed at the bottom end of the rear wall 13 joins at the outside end in the widthwise direction with the side wall side flange 14 formed to go around to the rear at the bottom end of the side wall 12 as shown in FIG. 4 . As a result, the rigidity of the entire side frame 11 further increases. The lower member frame 31 is a member in an approximately U shape viewed from above as shown in FIGS. 2 and 9 , and is formed by machining a single plate metal member. The lower member frame 31 includes a first extension portion 32 extending in the widthwise direction, and second extension portions 33 extending forward from both ends in the widthwise direction of the first extension portion 32 . The first extension portion 32 is a portion arranged between the side frames 11 in the widthwise direction, and attached to the rear walls 13 of the side frames 11 , particularly the member frame attachment portions 13 a . Specifically, each of both ends in the extension direction of the first extension portion 32 is attached to the member frame attachment portion 13 a by way of the laser welding in a state in which teach end is in contact with a front surface of the member frame attachment portion 13 a. Moreover, a through hole 32 b communicating with a hole (not shown) formed on the member frame attachment portion 13 a when the first extension portion 32 is attached to the member frame attachment portion 13 a is formed on an extension direction end of the first extension portion 32 as shown in FIG. 6 . The hole 32 b is used to fix the lower member frame 31 when the members constructing the seat back frame F 1 are assembled with each other, and a fixing jig, not shown, is inserted into the hole 32 b during the assembly. A detailed description is now given of the shape of the first extension portion 32 , and a bottom end position of the first extension portion 32 at a center in the extension direction is located somewhat above the bottom end position at the ends in the extension directions as appreciated from FIG. 3 . In other words, the first extension portion 32 has such a shape that the bottom end somewhat rises at the center in the extension direction in this seat S. A use of this seat S as a front seat is promoted by the provision of the first extension portion 32 shaped in this way. More clearly, feet of a passenger on the rear seat may enter a space located below the lower member frame 31 of the front seat. If the bottom end at the center in the extension direction is located above the bottom ends at the extension direction ends in the first extension portion 32 out of the lower member frame 31 , an interference of the feet of the passenger with the lower member frame 31 can be suppressed. On the other hand, the extension direction ends of the first extension portion 32 are wider in the top to bottom direction than the center in the extension direction, and the rigidity of the lower member frame 31 is secured as a result. Moreover, a protrusion portion 32 a protruding in an arc shape from a front surface (in other words, a portion recessed in an arc shape on a rear surface) is formed at a center in the top to bottom direction of the first extension portion 32 as shown in FIG. 3 . The protrusion portion 32 a is a so-called reinforcement bead, and is formed to a relatively long extent along the extension direction of the first extension portion 32 . Moreover, a first extension portion upper side flange 34 bent forward is formed at the top end of the first extension portion 32 as shown in FIGS. 4 and 6 . The first extension portion upper side flange 34 is formed from the one end to the other end in the extension direction of the first extension portion 32 to reinforce the first extension portion 32 . Further, the above-described rear wall side flange 15 (particularly an inside end in the widthwise direction of the flange 15 ) formed at the top end of the member frame attachment portion 13 a abuts against a portion somewhat closer to the center than the end position in the extension direction of the first extension portion 32 out of the first extension portion upper side flange 34 in this seat S as shown in FIG. 6 . In other words, the lower member frame 31 is attached to the member frame attachment portion 13 a as if the rear wall side flange 15 and the first extension portion upper side flange 34 continue to each other in this seat S. As a result, integrity between the lower member frame 31 and the side frame 11 is increased, and the rigidity of the neighborhood of a portion to which the lower member frame 31 is attached further increases in the side frame 11 . Moreover, a first extension portion lower side flange 35 bent to the front side is formed at the bottom end of the first extension portion 32 from the one end to the other end in the extension direction of the first extension portion 32 . As a result, the rigidity of the lower member frame 31 further increases. The second extension portions 33 are adjacent to the both ends in the extension direction of the first extension portion 32 in such a state as to cross the first extension portion 32 , an angle between the first extension portion 32 and the second extension portion 33 is approximately 90 degrees in this seat S. In other words, the rear end of the second extension portion 33 , along with the extension direction end of the first extension portion 32 , forms a corner of the lower frame member 31 . Then, the lower member frame 31 is attached to the member frame attachment portion 13 a so that the corner of the lower member frame 31 overlaps with the corner of the side frame 11 in this seat frame S as shown in FIG. 6 . In other words, the second extension portion 33 is located inside the side wall 12 of the side frame 11 in the widthwise direction, and overlaps with the side wall 12 . More specifically, the second extension portion 33 is attached to the side wall 12 by way of the laser welding in such a state as to abut against the inside surface 12 b of the side wall 12 . As described above, the second extension portion 33 of the lower member frame 31 is arranged in such a state as to abut against the inside surface 12 b of the side wall 12 of the side frame 11 in this seat S, the rigidity of the side wall 12 of the side frame 11 , particularly rigidity against the load acting in the widthwise direction increases, and the inward bend of the side frame 11 is suppressed. In other words, the rigidity can be increased to such a degree as to suppress the inward bend of the side frame 11 by arranging the second extension portion 33 inside the side wall 12 of the side frame 11 in the overlapping state. A detailed description is now given of a shape of the second extension portion 33 , and the second extension portion 33 is formed into a C shape viewed in the widthwise direction as illustrated in FIGS. 6 and 7 . In other words, the second extension portion 33 provided for this seat S is punched off at a center into a circular shape. Moreover, a half area in the bottom side of the front end of the second extension portion 33 is cut off in such a state as to continue to the circular punched-off portion. The second extension portion 33 is configured to include an upper portion 36 arranged above the circular punched-off portion and a lower portion 37 arranged below the circular punched-off portion as a result of the punching or cutting. Then, both the upper portion 36 and the lower portion 37 are joined to the side wall 12 by way of the laser welding in such a state as to abut against the inside surface 12 b of the side wall 12 of the side frame 11 . On the other hand, it should be understood that the circular punched-off portion in the second extension portion 33 is not joined to the side wall 12 of the side frame 11 . Then, the reclining mechanism 3 is arranged at a position opposite to the circular punched-off portion in this seat S across the side wall 12 . In other words, the area in which the circular punched-off portion is located in the side wall 12 of the side frame 11 corresponds to an area of the outside surface 12 a to which the reclining mechanism 3 is attached in this seat S. In other words, areas of the inside surface 12 b against which the upper portion 36 and the lower portion 37 of the second extension portion 33 abut on the side wall 12 of the side frame 11 are deviated from the area of the outside surface 12 a to which the reclining mechanism 3 is attached in this seat S. In the area of the outside surface to which the reclining mechanism 3 is attached in the side wall 12 , recesses and protrusions are formed as laser welding marks on the inside surface 12 b thereof. The second extension portion 33 is attached to the inside surface 12 b of the side wall 12 to avoid the portion on which the recesses and protrusions are formed, and the lower member frame 31 including the second extension portions 33 are thus satisfactorily attached. The area of the outside surface 12 a to which the reclining mechanism 3 is attached is circular viewed in the widthwise direction in the side wall 12 as described before in this seat S. On the other hand, the center of the second extension portion 33 of the lower member frame 31 is punched off in the circular shape to match the circular area M. Then, the second extension portion 33 is joined to the side wall 12 so that an outer edge of the circular area M and an inner edge of the circular punched-off portion in the second extension portion 33 match each other in this seat S In other words, the area of which the second extension portion 33 abuts against the inside surface 12 b is the area in the C shape along the outer edge of the circular area M in the side wall 12 in this seat S. More specifically, a portion located in the lower side of a center in the front to back direction of the upper portion 36 of the second extension portion 33 is cut off in a semicircular shape as shown in FIGS. 6 and 7 . Then, the second extension portion 33 is attached to the side wall 12 along an edge of the cutout and an upper portion of the outer edge of the circular area M. In other words, the upper portion 36 out of the second extension portion 33 is a portion arranged above the circular area M. On the other hand, the lower portion 37 of the second extension portion 33 extends forward in an arc shape as shown in FIGS. 6 and 7 . Then, the second extension portion 33 is attached to the side wall 12 so that the lower portion 37 aligns with a lower portion of the outer edge of the circular area M. In other words, the lower portion 37 out of the second extension portion 33 is a portion arranged below the circular area M, and extends in the arc shape along the outer edge of the circular area M. As described above, the second extension portion 33 is in the C shape along the outer edge of the area M (the area on the side wall 12 of the side frame 11 to which the reclining mechanism 3 is attached) viewed in the widthwise direction in this seat S. Then, the second extension portion 33 is joined to the side wall 12 so that the circular area M and the circular punched-off portion in the second extension portion 33 match each other. Conversely, the circular area M and the circular punched-off portion in the second extension portion 33 only need to align with each other when the second extension portion 33 is joined to the side wall 12 . As a result, the operation of attaching the lower member frame 31 to avoid the portion to which the reclining mechanism 3 is attached on the side wall 12 of each of the side frames 11 is promoted. Particularly when the seat back frame F 1 of this seat S is assembled, first, the reclining mechanism 3 is attached to the side wall 12 of each side frame 11 by way of the laser welding, and, then, the lower member frame 31 is attached to the side frames 11 . When the seat back frame F 1 is assembled in this assembly sequence, if the circular area M and the circular punched-off portion in the second extension portion 33 are aligned with each other, the attachment of the lower member frame 31 to avoid the attachment portion of the reclining mechanism 3 in the side wall 12 of the side frame 11 is further promoted. In other words, the configuration of punching the center of the second extension portion 33 in the circular shape to align with the outer edge of the circular area M is more effective when the seat frame F 1 is assembled in the assembly sequence. That the lower portion 37 of the second extension portion 33 extends in the arc shape to go around from the rear of the penetration shaft 3 b to the front of the penetration shaft 3 b in the state where the second extension portion 33 is joined to the side wall 12 in this seat S. Similarly, the upper portion 36 of the second extension portion 33 extends from the rear of the penetration shaft 3 b to the front of the penetration shaft 3 b . This configuration enables the attachment of the lower member frame 31 to the side walls 12 of the side frames 11 while the attachment portions of the reclining mechanism 3 on the side walls 12 of the side frames 11 are avoided, and the interference with the penetration shaft 3 b is further avoided. Moreover, the portion increased in the rigidity by the attachment of the lower member frame 31 out of the side wall 12 of the side frame 11 extends in the front to the back direction, and the rigidity of the side frame 11 further increases against the load acting in the widthwise direction Moreover, the upper portion 36 and the lower portion 37 of the second extension portion 33 are respectively laser-welded to the side wall 12 of the side frame 11 as described before in this seat S. Then, a welded area X 1 between the upper portion 36 and the side wall 12 extends in an arc shape in the front to the rear direction so that a portion of the welded area X 1 locates in front of the penetration shaft 3 b as shown in FIG. 7 in this seat S. Similarly, a welded area X 2 between the lower portion 37 and the side wall 12 extends in an arc shape in the front to the rear direction so that a portion of the welded area X 2 is located in the rear of the penetration shaft 3 b. As described above, each of the welded areas X 1 and X 2 is an area having a certain length in the front to the back direction in this seat S, and the upper portion 36 and the lower portion 37 of the second extension portion 33 are thus respectively fixed to the side wall 12 of the side frame 11 satisfactorily. Further, each of the welded areas X 1 and X 2 extend in the front to the back direction, and a strength against the load acting in the front to the back direction can be secured. As a result, even if a load in the front to the back direction acts on the side frame 11 and the lower member frame 31 , a detachment in the welded areas X 1 and X 2 can be suppressed, and the joint state between the second extension portions 33 of the lower member frame 31 and the side walls 12 of the side frames 11 can be stably maintained. The welded area X 1 between the upper portion 36 and the side wall 12 is the arc area corresponding to approximately ⅓ of the circumference about the penetration shaft 3 b , and the welded area X 2 between the lower portion 37 and the side wall 12 is an arc area corresponding to approximately ⅙ of the circumference in this seat S. Further, both the welded areas X 1 and X 2 are separated from each other. Both the welded areas X 1 and X 2 do not correspond to the entire circumference about the penetration shaft 3 b , and are separated from each other in this way. Therefore, when the seat back frame F 1 is assembled, a welding operation can be carried out more easily than a case in which the entire circumference about the penetration shaft 3 b is continuously laser-welded. Flanges bent inward in the widthwise direction are respectively formed on the upper portion 36 and the lower portion 37 of the second extension portion 33 as shown in FIGS. 4 and 6 . Specifically, a second extension portion top side flange 38 including a top end bent inward in the widthwise direction is formed on the upper portion 36 of the second extension portion 33 . The second extension portion top side flange 38 corresponds to a bent portion, and is formed from a front end to a rear end of the upper portion 36 in order to reinforce the second extension portion 33 . The formation of the flange 38 for the reinforcement at the top end of the upper portion 36 of the second extension portion 33 as describe above increases the rigidity of the lower member frame 31 itself, and, as a result, the rigidity of the side frame 11 to which this frame 31 is attached also increases. The second extension portion top side flange 38 continues to the first extension portion top side flange 34 formed at the top end of the first extension portion 32 as illustrated in FIG. 4 . As a result, the rigidity of the entire lower member frame 31 further increases. On the other hand, a second extension portion bottom side flange 39 including a bottom end bent inward in the widthwise direction is formed on the lower portion 37 of the second extension portion 33 as shown in FIGS. 4 and 6 . The second extension portion bottom side flange 39 corresponds to a second extension portion side bent portion, and is formed from a front end to a rear end of the lower portion 37 in order to reinforce the second extension portion 33 . The lower portion 37 extends in the arc shape to go around from the rear side to the front side of the penetration shaft 3 b as described before, and the second extension portion bottom side flange 39 thus also extends in an arc shape. Then, the front end of the second extension portion bottom side flange 39 overlaps with a rear end extending in an arc shape at a bottom end position of the side wall 12 out of the side wall side flange 14 formed on the side wall 12 of the side frame 11 in the state in which the second extension portion 33 is joined to the side wall 12 as shown in FIG. 6 in this seat S. More specifically, the lower portion 37 of the second extension portion 33 extends so that the second extension portion bottom side flange 39 aligns with the side wall side flange 14 , and the front end of the second extension portion bottom side flange 39 overlaps with the rear end of the side wall side flange 14 . In other words, the lower member frame 31 is attached to the side frame 11 as if the second extension portion bottom side flange 39 and the side wall side flange 14 continued to each other in this seat S. As a result, integrity between the lower member frame 31 and the side frame 11 , particularly integrity with the bottom end of the side wall 12 is increased, and the rigidity of the neighborhood of the portion to which the lower member frame 31 is attached further increases in the side frame 11 . Further, the second extension portion bottom side flange 39 connects to the first extension portion bottom side flange 35 formed at the bottom end of the first extension portion 32 as shown in FIG. 4 . As a result, the rigidity of the entire lower member frame 31 further increases. A description is given of the configuration example of the seat frame for the vehicle seat according to various embodiments of the present invention, but these are merely examples for promoting the understanding of the present invention, and do not limit the present invention. In other words, it should be understood that the shapes, dimensions, arrangements, and the like described before can be changed or improved without departing from the purpose of the present invention, and equivalents thereof are included. Moreover, the second extension portion 33 of the lower member frame 31 abuts against the inside surface 12 b on the side wall 12 of the side frame 11 in the embodiment. On the other hand, the area of which the reclining mechanism 3 is attached on the outside surface 12 a is the circular area M viewed in the widthwise direction on the side wall 12 . Then, the area of which the second extension portion 33 abuts against the inside surface 12 b is the area in the C shape along the outer edge of the circular area M in the side wall 12 . In other words, the second extension portion 33 includes the upper portion 36 arranged above the circular area M and the lower portion 37 arranged below the circular area M. However, the configuration is not limited to this case, and the second extension portion 33 may have such a configuration as to include a portion corresponding to only one of the upper portion 36 and the lower portion 37 . Moreover, though the flanges (second extension portion top side flange 38 and the second extension portion bottom side flange 39 ) for the reinforcement are provided respectively for the upper portion 36 and the lower portion 37 according to the embodiment, the configuration is not limited to this example, and a configuration without including the formed flanges for reinforcement may be adopted. REFERENCE NUMERALS S this seat S 1 seat back S 2 seat cushion S 3 headrest S 3 a pillar F this frame F 1 seat back frame F 2 seat cushion frame fs guide stay R slide rail mechanism Ru upper rail Rx support portion M circular area X 1 , X 2 welded area 1 side portion frame 3 reclining mechanism 3 a reclining mechanism main body 3 b penetration shaft 4 height adjustment mechanism 5 operation lever 6 turn link 7 a sector gear 7 b pinion gear 11 side frame 12 side wall 12 a outside surface 12 b inside surface 12 c hole 13 rear wall 13 a member frame attachment portion 14 side wall side flange 15 rear wall side flange 21 upper frame 22 bent portion 23 upper member frame 31 lower member frame (connection frame) 32 first extension portion 32 a protrusion portion 32 b hole 33 second extension portion 34 first extension portion top side flange 35 first extension portion bottom side flange 36 upper portion 37 lower portion 38 second extension portion top side flange 39 second extension portion bottom side flange

A seat frame for a vehicle seat has side frames disposed on both ends of a seat back frame in the width direction, and a bottom member frame for connecting the bottom ends of the side frames which attach to a seat cushion, wherein: each side frame has a side wall which is positioned on the outside in the width direction and which extends in the vertical direction, and a back wall which extends from the side wall towards the inner side in the width direction; and the lower member frame has a first extension portion extending along the width direction, and second extension portions extending from both ends of the first extension portion in the width direction towards the front. The second extension portions are positioned further inward than the side walls in the width direction and overlap with the side walls.

This application is a divisional of copending application Ser. No. 07/471,610, which was filed on Jan. 29, 1990, now U.S. Pat. No. 5,083,447. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine or laundry machine equipped with an optical sensor for detecting the light permeability of a detergent or rinse water in a washer tank. 2. Description of the Prior Art A washing machine of the type referred to above, namely, a washing machine equipped with an optical sensor for detecting the light permeability of a solution of washing detergent, i.e., for detecting the amount of light that can penetrate the detergent solution, has been disclosed in Japanese Patent Laid-open Publication No. 61-50595. More specifically, the washing machine of Tokkaisho 61-50595 is provided with an optical sensor comprised of light emitting and light receiving elements confronting each other in a washer tank, whereby the light permeability of the detergent solution in the washer tank is detected using an output of the light receiving element. A control circuit to which is generated an output of the sensor obtains data depicting the dirt contents of the laundries on the basis of the time period consumed from the start of washing until the light permeability detected by the optical sensor decreases to a predetermined value (20% of the light permeability of clear water), and the washing machine is operated according to the dirt content data of the control circuit. Meanwhile, a washing machine disclosed in Japanese Patent Laid-open Publication No. 61-159999 has been devised taking note of the fact that the light permeability detected by the optical sensor gradually increases after the start of washing, and thereafter it gradually decreases. A time point at the interface between the increase and decrease of the light permeability is set as an initial value of the data. In this washing machine, the type of detergent and the like are detected on the basis of both the time spent before the light permeability reaches the interface after the start of washing, and the changing width of the light permeability. In the washing machine disclosed in Japanese Patent Laid-open Publication NO. 61-50595, however, if the light emitting surface of the light emitting element or the light receiving surface of the light receiving element is stained, the light intensity coming from the light emitting element to the light receiving element lessens thereby diminish an output from the light receiving element. Accordingly, the light permeability detected by the optical sensor is a lower value than the actual value of the light permeability of the detergent in the washer tank. In consequence, the light permeability detected by the optical sensor reaches the predetermined value after the start of washing more quickly in comparison to the case where the elements are not stained. Therefore, the dirt content is erroneously detected. Particularly, since during use of the washing machine laundries and detergent are put in the washer tank, the light emitting and receiving elements provided in the washer tank are unavoidably stained. Moreover, the amount of the stain is generally increased in proportion to the usage time of the washing machine. As a result, the detecting accuracy of the optical sensor deteriorates with time. Accordingly, the optical sensor cannot be relied upon for a long service in the detection of the dirt content of laundries. Meanwhile, the change in the light permeability of the detergent solution in the washer tank is greatly influenced by the type of the detergent being used. Liquid detergent changes the light permeability significantly less than powdery detergent, and the light permeability of liquid detergent may not be reduced to 20% of that of clear water. In such case, it is impossible to obtain the dirt content data. Therefore, the washing machine disclosed in Tokkaisho 61-50595 is not able to control washing operation in a manner which is responsive to the type of the detergent being used. On the other hand, the washing machine disclosed in Tokkaisho 61-159999 is designed to detect the type of cleanser. However, according to the disclosed detecting method the type of the detergent can be detected only when the detergent is supplied into the tank before the water is added at the start of washing. In other words, if the detergent is put into the tank after the start of washing (after the start of stirring), the light permeability detected by the optical sensor declines after the start of washing. However, since the washing machine is arranged to operate based on the notion that the light permeability detected by the optical sensor increases at the start of washing and then, gradually decreases, the washing machine cannot detect the type of the detergent if the detergent is put into the tank after the start of washing. In addition, the change in the light permeability of the optical sensor is dependent not only on the type of detergent, but is also dependent on the amount of the detergent, and accordingly the light permeability detected by the optical sensor does not always follow a constant pattern of increasing once after the start of washing and thereafter decreasing. SUMMARY OF THE INVENTION A primary object of the present invention is to provide a washing machine which is arranged to detect the dirt content of the laundries with a high degree of accuracy, even when light emitting and light receiving elements of an optical sensor are stained. A second object of the present invention is to provide a washing machine which is arranged to control washing and rinsing operation without being influenced by the staining of the optical sensor. A third object of the present invention is to provide a washing machine which is arranged to control washing and rinsing operations using the data of the volume of laundries in a washer tank and the light permeability detected by an optical sensor. A fourth object of the present invention is to provide a washing machine which is arranged to correctly detect the type of detergent in use without being influenced by the amount of the detergent used or the time the detergent is placed into the washer tank. A fifth object of the present invention is to provide a washing machine which is arranged to control washing and rinsing operations in accordance with the type of detergent in use. A sixth object of the present invention is to provide a washing machine which is arranged to control washing and rinsing operations on the basis of three data sets, namely data directed to the volume of laundries in a washer tank, the light permeability detected by an optical sensor and the type of detergent being used. In accomplishing the above-described objects, a washing machine according to a first embodiment of the present invention is provided with an optical sensor comprised of a light emitting element and a light receiving element for detecting the light permeability of a detergent solution and rinse water in a washer tank, an output control unit for controlling an output generated from the light emitting element, and a storage unit. The control unit controls the light emitting element such that the light permeability of water or air in the washer tank becomes a reference value for the storage unit. In the washing machine, a reference value of the light permeability of supplied water is made different from that of air. An output of the light emitting element is controlled by the output control unit based on the reference value of the light permeability of the water or air, which is determined by a signal from a water level detecting unit. Moreover, the above output control based on the reference value of supplied water is effected when the water level detecting unit detects the water as not being lower than a predetermined level. The data of outputs of the light emitting element or data of the light permeability when the optical sensor is set at the reference value is stored in the storage unit, which is utilized for a succeeding output control. According to a second embodiment of the present invention, the washing machine is provided with an optical sensor comprised of a light emitting and light receiving elements for detecting the light permeability of a detergent solution and rinse water in a washer tank, an output control unit for controlling an output from the light emitting element, a storage device, and a control unit for controlling washing and rinsing operations. The output control unit controls the light emitting element such that the light permeability of water or air fed into the washer tank becomes a reference value, to thereby initialize the optical sensor. Moreover, the control unit controls the washing or rinsing operation based on the change of the light permeability indicated by the optical sensor. The output control is carried out during the supply of clear water. The washing operation is controlled by the saturating time from the start of washing until the light permeability of the optical sensor becomes approximately constant, and the changing width of the light permeability of the optical sensor, so that an additional washing time from the saturating time point is arranged on the basis of the changing width of the light permeability. According to a third embodiment, the washing machine is provided with an optical sensor comprised of a light emitting and light receiving elements for detecting the light permeability of a detergent solution and rinse water in a washer tank, a storage devices, a control unit for controlling washing and rinsing operations, and a volume sensor for detecting the volume of laundries in the washer tank. The control means controls the washing or rinsing operation based on the data of the volume sensor and the changing width of the light permeability of the optical sensor indicated during washing or rinsing operation. Moreover, according to this embodiment, the control unit sets the upper and lower limits of the washing time from the volume of laundries detected by the volume sensor. According to a fourth embodiment of the present invention, the washing machine is provided with an optical sensor comprised of a light emitting and a light receiving elements for detecting the light permeability of a detergent solution and rinse water in a washer tank, and a judging unit for judging the detergent type. The judging unit judges whether liquid detergent or powdery detergent is used through comparison of a reference light permeability of the optical sensor which is based on the light permeability of water or air fed into the washer tank with the light permeability of the optical sensor shown during the washing operation. According to a fifth embodiment of the present invention, the washing machine is provided with an optical sensor comprised of a light emitting and a light receiving elements for detecting the light permeability of a detergent solution and rinse water in a washer tank, a judging unit for judging a detergent type, and a control unit for controlling washing and rinsing operations. The judging unit judges the detergent type, i.e., liquid or powder, through comparison of a reference light permeability of the optical sensor with the light permeability indicated during the washing operation, whereby the control unit controls washing or rinsing operation in accordance with the judged type. According to a sixth embodiment of the present invention, the washing machine is provided with an optical sensor comprised of a light emitting and a light receiving elements for detecting the light permeability of a detergent solution and rinse water in a washer tank, a volume sensor for detecting the volume of laundries in the washer tank, a judging unit for judging the detergent type, and a control unit for controlling washing and rinsing operations. The control unit controls the washing or rinsing operation based on the data of the laundry volume detected by the volume sensor and the detergent type judged by the judging unit. In the washing machine of the first embodiment of the invention, an output of the light emitting element is controlled based on a reference value of the light permeability of water or air which has a high light permeability, to initialize the optical sensor. Consequently, the dirt content of the laundries is detected by the relative change of the light permeability from that of water or air, without being influenced by stains at a drainage path in which the optical sensor is provided, thus accomplishing an accurate detection of dirt content. Moreover, since the light permeability of water is different from that of air, the reference value is changed between water and air, so that the initial setting of the optical sensor is enabled both in the case of water and in the case of air. Further, if the water level detecting device detects no water, the light emitting element of the optical sensor is controlled on the basis of the reference value of air. On the contrary, if water is detected by the detecting device, the light emitting element is controlled on the basis of the reference value of air. Moreover, the light emitting element is controlled during a previous supplying time of rinse water such that an output signal of the optical sensor becomes a set value, and this controlling data is stored. Therefore, at the coming start of washing, the light emitting element is so controlled by the stored controlling data as to generate an output of a fixed value, to thereby detect the change of data after washing and stirring. In the case where only the air is present in the washer tank before the start of washing, since it is feared that the optical axis of each element of the optical sensor may be deviated because of the adhesion of water drops, an output of the light emitting element is controlled relatively larger as compared in the case where there is clear water in the tank. Although the output signal from the optical sensor becomes a Hi level and may exceed beyond the dynamic range when the water is actually fed in the tank, the data stored in the storage device is useful to solve such problem. Therefore, the change of the output signal due to the real dirt content can be detected. Further, in the second embodiment of the present invention, the light permeability is detected by the optical sensor after the sensor is initialized, so as to control the washing or rinsing operation. Accordingly, the optical sensor positively works for a long period of time without being affected by staining. Moreover, the optical sensor is initialized during the supply of rinse water, the light permeability of the clear water can be used as a reference value. Since washing is controlled by the saturating time spent before the saturating time point of the change of the optical sensor and by the changing width of the output of the optical sensor, the quality of stains related to the saturating time and the volume of stains related to the output changing ratio of the optical sensor can be detected, to thereby facilitate an optimum control of washing and rinsing operations. In the washing machine according to the third embodiment of the present invention, washing by detergent solution or by clear water can be controlled in consideration not only of the dirt content of the laundries shown by the optical sensor, but also in consideration of the laundry volume in the washer tank. Therefore, the washing machine can operate in the similar manner as if it were by a user's own control. According to the fourth embodiment of the present invention, taking note of the fact that the kind of a detergent can be known through comparison of the light permeability after the start of washing with that when the water is not supplied, that is, the light permeability of air as a reference, in the case where liquid detergent is used, for example, the light permeability after the start of washing is reduced to approximately 80% based on the reference light permeability of the air, while, in the case of powdery detergent, the light permeability after the start of washing is decreased to about 40-60%. Therefore, this conspicuous change of the light permeability enables the judgement as to the type of the detergent. Since the change of the output from the optical sensor is detected while rinse water is being supplied, namely, based on the light permeability of clear water, the relative change of the output is approximately equivalent to the change corresponding to the absolute volume of dirt content, and therefore it becomes possible to detect the volume of dirt content. In the case of powdery detergent, the output change of the optical sensor caused only by the dirt content of the detergent solution is approximately 50% and accordingly, the change thereafter, i.e., over 50% corresponds to the amount or degree of dirt content. In other words, it becomes possible to detect the presence of the detergent and the dirt content thereof by the present embodiment. According to the fifth embodiment of the present invention, since washing is arranged to be controlled in accordance with the detergent type, and data of detergents types which greatly affect the detection by the optical sensor is added, washing or rinsing control with high accuracy can be realized. According to the sixth embodiment of the present invention, since the data of detergents types and the data of volume of the laundries are added to the dirtiness data obtained by the optical sensor, washing can be performed under more accurate control. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and features of the present invention will become apparent from the following description taken in conjunction with preferred embodiments thereof with reference to the accompanying drawings in which throughout like parts are designated by like reference numerals and in which: FIG. 1 is a circuit diagram of an optical sensor of a washing machine according to one embodiment of the present invention; FIG. 2 is a block diagram showing the circuit structure of the washing machine of FIG. 1; FIG. 3 is a flow-chart showing the controlling operation of the washing machine of FIG. 1; FIG. 4 is a graph showing the change of an output of the optical sensor of FIG. 1; FIG. 5 is a table showing judging contents in the controlling operation of the washing machine of FIG. 1; FIG. 6 is a cross sectional view of the washing machine; FIG. 7 is a circuit diagram of an optical sensor of a washing machine according to a modified embodiment of the present invention; FIG. 8 is a graph showing an output of the optical sensor of FIG. 7; FIG. 9 is a flow chart showing the setting of the optical sensor at the start of washing; FIG. 10 is a flow chart showing the change detecting operation of the optical sensor; FIG. 11 is a flow chart of a subroutine for setting and storing an output of the optical sensor to a reference value; FIG. 12 is a flow chart showing the controlling operation of the optical sensor before washing; FIG. 13 is a graph showing the relation between the dirt content and the changing ratio of an optical sensor output V1 with respect to an optical sensor output Vo during the supply of water; FIG. 14 is a timing chart of an output signal of the optical sensor from the start of washing to drying; FIG. 15 is a graph showing the controlling contents for the washing time; FIG. 16 is a flow chart showing the controlling operation of washing; and FIG. 17 is a flow chart showing the output controlling operation for the optical sensor. DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIGS. 1-16, the structure of an automatic washing machine according to one preferred embodiment of the present invention will be described. The washing machine shown in FIG. 6 is provided with a washer tank 1 which serves also as a dryer tank (hereinafter referred to as a washer tank). A stirring vane 2 is rotatively placed in the bottom section inside the washer tank 1. A water reservoir 3 housing the washer tank 1 is supported by a main body 5 of the washing machine through a suspension 4, so that the water reservoir 3 is restricted from vibrating. A lid 5a which is freely openable and closable is provided in the upper portion of the main body 5. There is a motor 6 below the water reservoir 3, the rotation of which is transmitted to the stirring vane 2 through a transmission mechanism 7. At the time of drying, the transmission mechanism 7 also transmits the rotating force of the motor 6 to the washer tank 1. Further, a water exit 9 formed in the bottom portion of the water reservoir 3 is communicated to a drain valve 10 through a drainage path 11. A light emitting and receiving unit 8 comprised of a light emitting element and a light receiving element is installed in a part of the drainage path 11. Referring to a block diagram of FIG. 2, the circuit construction of the washing machine will be described hereinabelow. In FIG. 2, an alternating current source 12 supplies power to a control unit 13, the motor 6 provided with a phase according capacitor 14, the drain valve 10 and a feed valve 15. The control unit 13 has a microcomputer 16 which is the center of the controlling operations. At an input of the microcomputer 16 are connected a cover opening/closing detecting device 17 which detects whether the lid 5a is opened or closed, a water level detecting device 18 for detecting the water level within the washer tank 1, an optical sensor 19 including the light emitting and receiving unit 8 which detects the light permeability of a detergent solution and rinse water in the washer tank 1, and a volume detecting device 20 for detecting the volume of laundries in the washer tank 1 using the change of a terminal voltage of the capacitor 14 when the motor 6 is turned off. The volume detecting device 20 counts the number of pulses of the capacitor 4 when the motor 6 is controlled in the normal or reverse rotation thereof or the motor 6 is turned off, and determines that there are a relatively large amount of laundries in the washer tank when the number of pulses is small. On the other hand, at an output side of the microcomputer 16 is connected a switching device 21 which controls the load of the motor 6 and the like in response to an output signal from the microcomputer. Moreover, the microcomputer 16 is further connected with an operation display device 22 for transmitting and receiving signals therewith. The above-mentioned control unit 13 will operate in the following manner. In the first place, when the microcomputer 16 receives a start signal from the operation display device 22, the microcomputer carries out the programmed operation processes, that is, washing using a detergent solution, rinsing using clear water and drying. More specifically, when the water is supplied in the washing process, the microcomputer 16 controls the feed valve 15 to be opened and the drain valve 10 to be closed through the switching device 21. In the middle of the supply of water, when the water level is low, the motor 6 is driven to rotate the stirring vane 2 for a predetermined time. Immediately after the rotation of the motor 6 is stopped, the microcomputer 16 reads a signal from the volume detecting device 20 so as to determine the volume of the laundries from the attenuating change of the terminal voltage of the capacitor of the motor 6. Consequently, a water stream, washing time, rinsing time, drying time, etc., which are appropriate for the detected volume of laundries are determined, and each process is carried out. Referring now to FIG. 1, the specific structure of the optical sensor 19 which is a main feature of the present invention will be explained. The microcomputer 16 is provided with a PWM output terminal 16a which freely controls an output pulse width. An output pulse from the PWM output terminal 16a is, via a D/A converter 19a, inputted to a base of a transistor 19b. In other words, an anode current in a light emitting diode 8a which is a light emitting element of the light emitting and receiving unit 8 and connected to a collector of the transistor 19b is controlled in accordance with the pulse width. The D/A converter 19a and transistor 19b constitute a current variable means for the light emitting element. A phototransistor 8b which is a light receiving element for receiving light from the light emitting diode 8a has an emitter connected to a resistor 19d, and an output signal V e (light permeability) of the phototransistor 8b can be output as a voltage. This output signal Ve is connected to an A/D input terminal of the microcomputer 16 to be A/D converted. The microcomputer 16 controls the optical sensor 19 as follows. Referring to a flow chart of FIG. 3, the water level detecting device 18 detects the presence or absence of water in the washer tank 1 in step 140. Without water, the current of the light emitting diode 8a is increased in step 141 and, the optical sensor is initialized such that the output voltage Ve of the phototransistor 8b becomes a reference value Vo in step 142. That is to say, the light permeability of air is set as a reference value. The pulse width from the PWM output terminal 16a should be increased when the current of the light emitting diode 8a is to be increased. Because of this initial setting of the optical sensor, a decrease in the detecting accuracy due to the decline of the output voltage of the phototransistor 8b resulting from the staining of to the surface of the light emitting diode 8a or phototransistor 8b can be prevented. In the case where the water is already supplied in the washer tank 1, the optical sensor is set with the current of the light emitting diode 8a employed in the previous operation, in step 143. Then, in step 144, a constant current is fed to the light emitting diode 8a. It is detected in step 145 whether the washing process is selected. In the event that the washing process is not selected, the flow proceeds to a succeeding process in step 146 (for example, rinsing process). In the washing process, if there is no water in the tank 1, the volume detecting device 20 detects the volume of laundries, and the water is fed to a predetermined water level, and thereafter the stirring vane 2 is rotated to produce the water stream. The change in the output voltage Ve of the phototransistor 8b after the start of stirring is indicated in the graph of FIG. 4 in which lines A and B show the voltage Ve change when a powder detergent is used, and a line C indicates the change when a liquid detergent is used. If washing is completed before a time point T1 (e.g., the user sets the washing time period shorter than T1), the operation flow advances to a next process (steps 147 and 148). In step 149, the output voltage Ve is set to be Vel at the time point T1 after the start of washing. In step 150, it is judged whether Vel is larger than the judging value Vx set for judging the type of detergent. If Vel>Vx holds (in the case shown by line C in FIG. 4), a flag denoting liquid detergent is set in step 151. Or, if Vel≦Vx holds (in the case shown by lines A and B in FIG. 4), a flag denoting powder detergent is set up in step 152. Since the light permeability of the liquid detergent is decreased to 80% in comparison with the reference value Vo, which is the light permeability when no water is present in the washer tank, namely, the light permeability of the air, while the light permeability of powder detergent is lowered to 40-60% Vx is set to be at about the middle of the light permeability between the liquid and powder detergents to thereby enable the detection of the detergent type. The changing ratio ΔVe of the output voltage Ve is detected in step 153. It is regarded as a saturating point of the light permeability when ΔVe is smaller than a set value. A difference ΔV between the reference value Vo of the light permeability of air and the output voltage Vel is obtained in step 154. The time to the saturating point is T3. With reference to a table of FIG. 5, how the difference ΔV and the time T3 are utilized for the control of washing will be described. In FIG. 5, the difference ΔV and the time T3 are classified into three groups, respectively, large, middle and small. By way of example, when both ΔV and T3 are small, the washing time is shortened, whereas, when both ΔV and T3 are in the middle group, the washing time is ordinary (middle). In the manner as above, data on the difference ΔV and time T3 is fuzzy-controlled for washing. Furthermore, according to the present invention, washing can be controlled by three data sets, i.e., volume data of laundries detected by the volume detecting device 20 in addition to the data ΔV and T3, which will be described hereinbelow. In other words, the judging result from ΔV and T3 is classified into three groups, namely, large, middle and small. By comparing the result with the washing time determined by the volume of laundries detected by the detecting device 20, the washing time is controlled 3 minutes longer in the event that the result is large. If the result is middle, the washing time is maintained as it is. On the other hand, if the result is small, the washing time is shortened by two minutes. Thus, washing can be controlled in an optimum manner. If the washing time is determined from the total point of view based on the detected volume of the laundries W1 and the dirt content degree W2 (determined by ΔV and T3), washing can be controlled as if it were done by the user himself or herself, with the volume and dirt content of laundries taken into consideration as when the user selects the washing time. Although the foregoing description is related to the detecting of the dirt content and to the controlling operation therefor in the washing process, the same also holds true in the rinsing process. Since ΔV changes in accordance with the detergent type as shown in FIG. 4, the value ΔV classified in the groups, large, middle and small in FIG. 5 may be changed corresponding to the detergent type. Moreover, the detecting accuracy of the saturating point of dirt may be rendered variable corresponding to the type of detergent. In the foregoing embodiment, since the optical sensor is set at the initial stage when the clear air is in the washer tank, the detection of dirt is based on the relative change of the light permeability from that of air, and accordingly the detection is free from influences of stains in the drainage path where the optical sensor is installed or the stains interfering with the light detection of the optical sensor, thereby realizing an accurate detection of dirt. In addition, since it is possible to detect the detergent type by the relative change of the output of the optical sensor between the time when the air is in washer tank and after the start of washing, the data of the detergent type can be utilized for an accurate detection of dirt and accordingly for an accurate control of washing. Hereinafter, an optical sensor and its control circuit of a washing machine according to a modified embodiment of the present invention will be explained with reference to FIG. 7. In FIG. 7, a pulse width controlling circuit (referred to a PWM circuit hereinafter) for controlling the current of the light emitting diode 8a in the light emitting and receiving unit 8, and an A/D converter for converting an analog signal to a digital signal is built in the microcomputer 16. A storage device 23 stores a control signal for controlling the current of the light emitting diode 8a (output controlling signal), namely, it stores data of PWM signals. This storage device 23 uses, for example, a non-volatile memory. The PWM signal from the microcomputer 16 is added to the D/A converter 19a (generally, an integrating circuit) to be converted to a direct current voltage to thereby control the voltage at the base of the transistor 19b. The collector of the transistor 19b is connected to the light emitting diode 8a, and the emitter thereof is connected to an emitter resistor 19c, thereby constituting a constant current circuit able to control the current of the light emitting diode 8a responsive to the base voltage. A switching transistor 19e is connected in series to the emitter resistor 19c, so that the current of the light emitting diode 8a is controlled on and off and pulse-driven by an output signal P1 of the microcomputer 16. A load resistor 19f of the phototransistor 8b, an emitter follower circuit of a transistor 19g, a resistor 19h and a capacitor 19i form a peak hold circuit so as to stabilize an output signal of the pulse-driven light emitting and receiving unit 8, thus reducing errors in A/D conversion. The change of an output of the optical sensor 19 in the entire process of operation is indicated in the graph of FIG. 8. In this case, the change denotes a change after the current of the light emitting diode 8a is controlled to generate a preset output. As is clear from FIG. 8, the light permeability during washing is detected by the change of the output of the optical sensor from the reference value Vo which is set when the rinse water is supplied (the light permeability is represented by ΔV/Vo×100% wherein ΔV indicates the difference between the output V1 and reference output Vo). The light permeability expresses the dirt content and cleanliness of the laundries. Also, the change of the output from the clear water at the time of rinsing is seen from FIG. 8. FIG. 9 is a flow chart showing how the optical sensor is set at the start of washing. Upon supply of the power in step 212, it is detected in step 213 whether or not the current I F of the light emitting diode 8a is set. If I F is set, the set value is inputted from the storage device (memory) 23 in step 214, and the microcomputer 16 sets If by the PWM signals based on the inputted data in step 215. If I F is not set in step 213, it is adjusted in step 216, and the PWM signal is controlled such that the output signal Vc of the optical sensor 19 is a set value, thereby controlling the output of the D/A converter circuit 19a of FIG. 7. The data read out from the storage device 23 is the data set at the previous rinsing time. The detecting flow of the change of the output of the optical sensor 19 during the washing process is indicated in FIG. 10. The light emitting diode 8a is pulse-driven at a set level periodically in step 221 to input data of outputs Vc of the optical sensor 19. Since the output data includes bubbles and noise components, such data at an extraordinarily low level is removed, and only signals of a suitable level are taken out in step 222. The changing ratio of the data Vc is obtained in step 223, and judged in step 224 whether it is a predetermined ratio. The light permeability when the changing ratio, becomes a predetermined ratio and the saturating time are stored in step 225 to determine the washing time in step 226. When the determined washing time has passed, washing is completed in step 227. Then, discharging of water and drying are carried out in step 228. After it is detected in step 229 whether the rinse water is filled in the tank, the current of the light emitting diode 8a is controlled such that the output signal Vc of the optical sensor 19 shows the reference value Vo. A flow chart of FIG. 11 explains the controlling process when the output signal of the optical sensor is set to be the reference value Vo. In step 232, the current If of the light emitting diode 8a is controlled. In step 233, the switching transistor is turned on to input the signal Vc of the optical sensor 19 into the microcomputer 16 for A/D conversion. Then, the switching transistor 19d is turned off in step 235. A difference ΔX between the reference value Vo and the input signal Vc is calculated in step 236. In step 237, PWM control is performed such that the difference ΔX is within a predetermined value. If the difference is within the predetermined value, the output controlling data is stored in the storage means 23, and the optical sensor 19 is fixed by the stored data thereafter turning on and off the current of the light emitting diode 8a. In the above-described embodiment, the output voltage of the optical sensor is set at the reference value at the supplying time of the rinse water, so that the dirt content or cleanliness of the laundries is detected by the change of the output voltage from the reference value. In general, the water supplied as rinse water has 100% light permeability. Therefore, the light permeability or dirt content of the water can be detected by the changing ratio of the output voltage of the optical sensor with respect to the reference value. Particularly, for detecting the dirt content of the laundries at the time of washing, the change of the light permeability from the clear water will carry out the detection. Further, since the previous reference value is arranged to be stored in the storage device 23, it may be useful in the case where washing is continuously performed subsequent to the previous one (in the case where water drops are still adhered to the optical sensor 19 because of the previous washing, resulting in an erroneous detection). Accordingly no complicated control is required even during continuous washing. The controlling process without the output controlling data will be described with reference to FIG. 12. In the event that the output controlling data is not found in step 240, or the data is found to be inappropriate, the presence or absence of water is detected in step 241. If the water is found to be above the minimum water level in step 241, that is, if there is some water in the washer tank, the output voltage of the optical sensor is set at the reference value Vo in step 243. On the contrary, if there is no water in the washer tank, the output voltage is set to a second reference value Vo'. This is because the refractive index is different for air and water. Since the reference value Vo for clear water is 1.1 times larger in comparison with the reference value Vo' for air, Vo' is set smaller than Vo. With reference to FIG. 13, the basic principle of the detection of dirt content and cleanliness will be described. Specifically, when the output from the light emitting diode 8a is made constant, the ratio between the generated light amount Io and the penetrating light amount I1 when the water is clear water is represented by I1/Io=e -k1 ., wherein k1 is a light absorbing factor and l is an optical path length. Similarly, when the water is dirty, the ratio between the generated light amount Io and the penetrating light amount I2 is indicated by I2/Io=e -k2 ., wherein k2 represents a light absorbing factor of the dirty liquid. If Io is constant, the following equation is held; I2/I1=e.sup.-e(k2-k1) Since the penetrating light amount I1 when the water is clear is proportional to Vo shown in FIG. 14, and the penetrating light amount I2 when the water is dirty is proportional to V1 of FIG. 14, an equation; V1/Vo=e.sup.-e(k2-k1) is obtained. Accordingly, it is understood that the changing ratio V1/Vo of the sensor output for the voltage Vo when the rinse water is supplied is changed logarithmically to the change of dirt content (the change of the light absorbing factor), as viewed from the graph of FIG. 13. In other words, ln(V1-Vo)=-Δk.l (Δk=k2-k1) Therefore, it is so determined that the larger the changing ratio is, the greater the dirt content is, thus increasing the washing time, or strengthening the stirring force. Although the current of the light emitting diode 8a is controlled through D/A conversion by the PWM controlling and integrating circuit in the foregoing embodiment, it may be effected by direct D/A conversion. Moreover, in setting the optical sensor at the reference voltage Vo, although it is easy if the current of the light emitting diode 8a is increased from 0, it takes much time. In addition, since the output control requires a good responding capability, the capacity of the capacitor 19i should be rendered small. The washing time can also be controlled in the other modification of the present invention, which will be described with reference to FIG. 15. The washing time TW is expressed by TW=TS+TF (wherein TS is a saturating time until the change of the output of the optical sensor becomes constant after the start of washing, and TF is the time corresponding to the changing ratio V1/Vo (Vo being the reference value and V1 being the output of the optical sensor at the saturating time point)). In considering the case where the light permeability does not reach the saturating point, a minimum value Tmin and a maximum value Tmax are set for the washing time, which are changed corresponding to the volume of the laundries. Therefore, when a relatively large amount of laundries are to be washed, Tmin and Tmax are large. The changing ratio V1/Vo is different for liquid detergent and powder detergent, that is, not smaller than 0.5 and smaller than 0.5, respectively. When the powder detergent is used for lightly soiled laundries, V1/Vo is approximately 0.5. As the dirtiness of the laundries increases, the changing ratio becomes smaller than 0.5. On the other hand, when the liquid detergent is used, if the laundries are a little dirty, V1/Vo becomes closer to 1, and it becomes smaller than 1 as the dirt content increases. Since the logarithmic value of V1/Vo is inversely proportional to the dirt content the laundries are much dirtier as the changing ratio V1/Vo becomes smaller. TF should be increased logarithmically in order to increase the washing time. The control of washing according to the present embodiment is carried out as shown in FIG. 16. When washing is started in step 300, IF controlling data stored in the previous rinsing process and the voltage data Vo are read from the storage device in step 301, thus controlling the output of the optical sensor. Step 302 is a volume detecting routine in which the volume of the laundries is detected, and the minimum and maximum washing times are determined in accordance with the detected volume of the laundries. After the start of stirring, the optical sensor is periodically controlled in step 303, generating the sensor output. In step 304, it is detected whether the sensor voltage is saturated to a predetermined value. When the output voltage is saturated, a saturation detecting flag is checked in step 305. Thereafter, the saturating time TS is stored in step 306, and further the changing ratio V1/Vo from the time of clear water (supplied as rinse water into the washer tank) is calculated in step 307. In step 308, TF is obtained based on the graph of FIG. 15. Then, in step 309, the washing time TW is obtained. When the washing time TW is consumed in step 310, the washing process is completed. It is possible to control the washing time to TW=TS+TF+TG in step 309. The time TG is changed corresponding to the volume of laundries. The dirt content is inversely proportional to the logarithmic value of the changing ratio V1/Vo, and accordingly, the optimum washing time can be obtained in accordance with the dirt content. The output control and storing operations in the rinsing process according to a modified embodiment will be described with reference to FIG. 17. At the first rinsing time in step 312, the output of the optical sensor is controlled during the supply of rinse water, i.e., before the rinse water is supplied to a set level, so that the output voltage Vo becomes a set value. In step 313, the water level of the supplied rinse water is detected. If the water level is not sufficient, rinse water is fed again in step 314. Then, if the sensor voltage does not reach the set value in step 316, the current IF of the light emitting diode is controlled by PWM signals in step 317. When the sensor voltage reaches the set value, the output controlling data (PWM signal data) and output signals Vo from the sensor are stored in steps 318 and 319, respectively. In the control of washing described above, even if the laundries are soiled with mud, and accordingly when the saturating time of the sensor voltage becomes short, the washing time can be changed and lengthened in accordance with the dirt content of the laundries (light permeability). Therefore, a large washing and cleansing power is secured. Likewise, when the oily stains are to be washed and therefore the saturating time is long, the washing time can be lengthened. In short, according to the washing machine of the present invention, it is possible to control washing in accordance with the quality and quantity of the dirt. Since the dirt of the laundries in general domestic use is easy to decompose by water and detergent, in such case, it will fit the user's sense to control the washing time in accordance with the changing ratio V1/Vo, with reducing the saturating time. In other words, when the changing ratio is small and the saturating time TS is short, the laundries are judged to be lightly soiled, whereby the washing time is set shorter. On the other hand, when the changing ratio is large, with a small saturating time TS, the laundries are judged to be considerably dirty, and the washing time is set longer. The washing machine of the present invention can realize this type of control. As is made clear from the foregoing description of preferred embodiments, the washing machine of the present invention is significantly effective as follows: (1) Since the optical sensor is initialized on the basis of the light permeability of water (clear water) or air supplied into the washer tank, a situation can be prevented in which an output of the optical sensor is erroneously decreased as a result of staining. Therefore, an erroneous detection by the optical sensor is avoided, and an accurate detection of dirt is ensured. (2) Since the reference value is changed between water and air, the optical sensor can be initialized both for water and for air. (3) Since it is so arranged as to detect the dirt of the laundries through detection of the light permeability of the optical sensor after the sensor is initialized, the detection is free from influences of stains to the optical sensor, and accordingly the optical sensor is reliably accurate for a long period of use. (4) Since the dirt of the laundries is detected on the basis of both the saturating time of the output of the optical sensor and the changing width of the output, the quality and quantity of the dirt can be taken into consideration in control of washing and rinsing. (5) Since there is provided, in addition to the optical sensor, a volume sensor for detecting the volume of the laundries, control of washing and rinsing can be carried out based on the data of the dirt detected by the optical sensor and the data of the laundry volume detected by the volume sensor. Therefore, control of washing and rinsing can be realized as if by the operator himself or herself. (6) Since the detergent type is detected through detection of the output from the optical sensor after the optical sensor is initialized at the reference value, the washing machine can utilize a wide variety of detergents. (7) Since washing and rinsing are controlled corresponding to the detergent type which greatly influences the optical sensor in detection of the light permeability, a highly accurate control is gained. (8) Since the data of the kind of detergent type, data of the laundry volume and dirt content data from the optical sensor are all together utilized for control, washing and rinsing can be controlled with a much higher accuracy. Although the present invention has been fully described by way of example with reference to the preferred embodiments thereof, it is to be noted here that various changes and modifications would be apparent to those skilled in the art. Such changes and modifications are to be understood as defined by the appended claims unless they depart therefrom.

A washing machine apparatus includes an optical sensor for detecting a light permeability of a liquid contained in a washer tank. The time duration of a washing cycle is determined in accordance with two variables. The first variable is a saturating time in which the detected light permeability becomes relatively constant. The second variable is the overall light permeability change during the washing cycle at the saturation time. The saturating time period and the light permeability change are fuzzy processed to obtain a remaining time duration of the washing cycle.

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Application No. 61/466,224, filed on Mar. 22, 2011. The entire disclosure of the above application is incorporated herein by reference. FIELD OF THE INVENTION This invention relates to adjustable dental tools and more particularly, to a novel apparatus where the head of the tool includes an accordion section which allows the tool to be bent and twisted for maximum adjustability. BACKGROUND OF THE INVENTION Often, a dentist's view and working environment in a patient's mouth is obstructed because of lack of adjustability of his dental mirror and/or instrument. A problem with current designs is that the adjustability, if any, is restricted to the location of the hinges or the orientation of the mirror and instrument. SUMMARY OF THE INVENTION The present invention contemplates an adjustable dental tool in which the working portion of the tool can be manipulated relative to the tool handle to position the head in a desirable configuration to carry out a task or to provide a better viewing angle within a patient's mouth. In one form, the present disclosure provides a dental tool that may include a head and a handle. The head may include a working portion and a neck. The neck may include a first end and a second end, and the working portion may extend from the first end. The handle may include a clamp and a socket. The socket may be configured to receive the second end of the neck. The second end may pivot within the socket to move the working portion and the neck relative to the handle. The clamp may be adapted to selectively fix the second end relative to the handle. In another form, the present disclosure provides a dental tool that may include a working portion and a neck. The neck may include a proximal end and a distal end. The working portion is coupled to the distal end of the neck. A sleeve couples to the distal end of the neck and is movable between a first position allowing the working portion to rotate relative to the neck and a second position restricting rotation of the working portion relative to the neck. In another form, the present disclosure provides a dental tool that may include a working portion and a neck. The neck may include a proximal end, a distal end and a first longitudinal axis extending between the proximal and distal ends. The working portion may be coupled to the distal end of the neck. A handle may include a first end, a second end and a second longitudinal axis extending between the first and second ends. The first end may be coupled to the proximal end of the neck, and the neck may be movable relative to the handle between a first position in which the first and second longitudinal axes are substantially collinear and a second position in which the first longitudinal axis is angled relative to the second longitudinal axis. The design offers the advantages of allowing different dental heads to be used with the same handle which will allow the tool to be sold in kits, thereby reducing the cost of the tool since only a single handle is needed for a multitude of dental heads. Further, the handle can include a single coupling portion on its proximal end for attachment of a single dental head, or it can include a plurality of coupling portions on both ends for attachment of a plurality of dental heads. The design offers an additional advantage of maximum adjustability of the dental head. The adjustable portion of the neck of the dental head provides for pivoting movement of the dental head relative to the proximal end of the dental head and radial twisting movement of the dental head relative to the longitudinal axis of the neck. The adjustable dental tool provides the dentist with the capability to adjust the dental head to a multitude of positions for optimal viewing or operation within a patient's mouth. Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: FIG. 1 shows a perspective view of the adjustable dental tool with a pivoting neck, threaded mirror head and handle, wherein the mirror head is positioned at a 90° angle relative to the handle; FIG. 2 shows an exploded view of the adjustable dental tool with the mirror head positioned at the 90° angle relative to the handle; FIG. 3 shows a top view of the pivoted neck and mirror head of FIG. 1 ; FIG. 4 shows a section view of the assembled dental tool with the mirror head positioned at the 90° angle relative to the handle; FIG. 5 shows a perspective view of the range of motion of the pivoting section of the neck of the dental tool; FIG. 6 shows a perspective view of a second embodiment of the head of the the dental tool; FIG. 7 shows a perspective view of a third embodiment of the head of the dental tool; FIG. 8 shows a perspective view of a fourth embodiment of the dental tool; FIG. 9 shows a perspective view of a fifth embodiment of the dental tool; FIG. 10 shows a perspective view of a sixth embodiment of the adjustable dental tool with the pivoting neck, threaded mirror head and handle, wherein the mirror head is positioned at a 0° angle relative to the handle; FIG. 11 shows an exploded view of the sixth embodiment of the adjustable dental tool with the mirror head positioned at the 0° angle relative to the handle; FIG. 12 shows a section view of the sixth embodiment of the dental tool with the mirror head positioned at the 0° angle relative to the handle; FIG. 13 shows a section view of the twistable function of the mirror head relative to the neck of the tool; FIG. 14 shows a section view of a seventh embodiment of the head of the dental tool; and FIG. 15 shows a section view of an eighth embodiment of the head of the dental tool. FIGS. 16A-C show various perspective views of the adjustable dental tool with a bendable, threaded, mirror head and handle; FIGS. 17A-C show various perspective views of the bendable section of the neck of the tool; FIG. 17D shows a perspective view of the twistable function of the bendable section of the neck of the tool; FIG. 17E shows a perspective view of the range of motion of the bendable section of the neck of the tool; FIGS. 18A-C show perspective views of three different embodiments of the head of the dental tool; FIGS. 19A-B show perspective views of a fourth and fifth embodiment of the dental tool; FIG. 20 shows a perspective view of a sixth embodiment of the dental tool; and FIGS. 21A-B show perspective views of a seventh embodiment of the dental tool. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. FIGS. 1-15 illustrate various views of an adjustable dental tool 10 including a handle 12 and a head 14 that can be placed in a patient's mouth. Referring to FIGS. 1-5 , the head 14 includes a neck 16 having a distal end 26 and a proximal end 27 . The neck further includes a ball 18 located on the proximal end 27 of the neck 16 and a working portion 20 on the distal end 26 of the neck 16 , which is in the form of a mirror 22 according to this embodiment. As will be discussed in greater detail below, the ball 18 can be pivoted to affix the head 14 and ultimately the working portion 20 , e.g. the mirror 22 , in a desired position. The head 14 additionally includes a male coupling portion 24 or female coupling portion on the distal end 26 of the neck, which is a male threaded portion 24 in this embodiment. The proximal end 28 of the working portion 20 includes a complementary female coupling portion 30 or male coupling portion, which is a female threaded portion 30 in this embodiment that is in engagement with the coupling portion 24 of the neck 16 . Referring specifically to FIG. 2 , the handle 12 includes a clamp 32 and a socket 34 coupled to a distal end 36 of the handle 12 for attaching the head 14 to the handle 12 and adjusting the neck 16 to a desired angle relative to the longitudinal axis of the handle 12 . The clamp 32 includes a male coupling portion 38 , 40 or female coupling portion on both its proximal 42 and distal 44 ends, which is a male threaded portion 38 , 40 in this embodiment. The distal end 36 of the handle 12 and a proximal end 42 of the socket 34 both include complementary female coupling portions 46 , 48 or male coupling portions, which are female threaded portions 46 , 48 in this embodiment that are in engagement with the coupling portions 38 , 40 of the clamp 32 . The socket 34 further includes a receptacle 50 for receiving the ball 18 on the head 14 of the adjustable dental tool 10 . As discussed in greater detail below, the ball 18 fits within the receptacle 50 so that the neck 16 exits through a slot 52 located in a distal end 54 of the socket 34 . The slot 52 allows the neck 16 to pivot in a range of 0° to 90° from the longitudinal axis of the handle 12 , in conjunction with the ball 18 as the ball 18 is rotated within the receptacle 50 , altering the position of the working portion 20 relative to the distal end 54 of the socket 34 (further demonstrated in FIG. 5 ). Further, the ball 18 may be twisted in a range of 0° to 360° both clockwise and counterclockwise in the radial direction along the longitudinal axis of the handle 12 , altering the position of the working portion 20 relative to the axis running the length of the handle 14 . The neck 16 may also be rotated and twisted simultaneously. The coupling of the clamp 32 and the socket 34 may be tightened such that the distal end 44 of the clamp 32 contacts the ball 18 and increases a compressive force on the ball 18 from the clamp 32 and the walls of the receptacle 50 . The application of the compressive force will cause the ball 18 to remain in its set position thereby temporarily fixing the position of the working portion 20 . As Illustrated in FIGS. 6 and 7 , the adjustable dental tool 10 may include a variety of working portions 20 . Specifically, FIG. 6 is a perspective view of an embodiment of the adjustable dental tool 10 including the working portion 20 illustrated as a pick head 56 . This embodiment includes the same remaining elements of the adjustable dental tool 10 illustrated in FIGS. 1-5 . Specifically, FIG. 7 is a perspective view of one other embodiment of the adjustable dental tool 10 including the working portion 20 that is illustrated as a cement spatula head 58 . This embodiment also contains the same remaining elements of the adjustable dental tool 10 illustrated in FIGS. 1-5 . FIGS. 8-9 illustrate embodiments of a dental tool 100 including a handle 112 , a head 114 , a neck 116 , and a working portion 120 wherein the neck 116 is fixed at a predetermined angle from the longitudinal axis of the handle 112 (for example only, 0°). The neck 116 includes a male coupling portion 122 or female coupling portion on a proximal end 124 of the neck 116 , which is a male threaded portion 122 in this embodiment. A distal end 126 of the handle 112 includes a complementary female coupling portion 128 or male coupling portion, which is a female threaded portion 128 in this embodiment that is in engagement with the coupling portion 122 of the neck 116 . The dental tool 100 may include a variety of different, interchangeable, working portions. The working portion 120 of the embodiment shown here is a mirror 130 . Specifically, FIG. 9 is a perspective view of another embodiment of the dental tool 100 including the working portion 120 that is illustrated as a pick head 132 . This embodiment also contains the same remaining elements of the dental tool 100 illustrated in FIG. 8 . Referring specifically to FIGS. 10-13 , an adjustable dental tool 200 includes all of the elements of the adjustable dental tool illustrated in FIGS. 1-7 and further illustrates an embodiment of the adjustable dental tool 200 where the rotational position of a ball 218 can be temporarily fixed in a range of 0° to 90° from the longitudinal axis of a handle 212 , and the radial position of the ball 218 relative to the axis running the length of the handle 212 is fixed. The ball 218 includes a raised portion 222 and a plurality of flat portions 224 . The raised portion 222 protrudes out of a receptacle 226 of a socket 228 and rests within a slot 230 , fixing the radial position of the ball 218 . The plurality of flat portions 224 engage with a complementary flat portion 232 of the receptacle, stopping the rotation of the ball at predetermined stop angles in the range of 0° to 90° from the longitudinal axis of the handle. A clamp 234 , including a male coupling portion 236 or female coupling portion on a distal 238 end of the clamp 234 that engages with a complementary male or female coupling portion 240 on a proximal 242 end of the socket 228 , may then be engaged to apply compressive pressure to the ball 218 , temporarily fixing the ball 218 , in the desired angle. Further, the adjustable dental tool 200 includes a sleeve 244 for adjusting the position of a working portion 220 relative to the axis running the length of the handle 212 . The sleeve 244 includes a male or female coupling portion 246 , which is a female threaded portion 246 in this embodiment. The coupling portion 246 on the sleeve 244 is engaged with a complementary male coupling portion 248 or female coupling portion on a distal end 250 of a neck 216 , which is a male threaded portion 248 in this embodiment. The sleeve may be threaded onto the distal end 250 of the neck 216 and provide a stop position for the working portion 220 . The working portion 220 includes a similar coupling portion 252 to the coupling portion 246 of the sleeve 244 , which is a female threaded portion 252 in this embodiment, and the coupling portion 252 of the working portion 220 is threaded onto the distal end 250 of the neck 216 and contacts a distal end 254 of the sleeve 244 . FIGS. 10-12 show the raised portion 222 having opposed flat surfaces and a rounded surface, the opposed flat surfaces being substantially parallel to each other, a plurality of the flat surfaces 224 extending perpendicularly from the raised portion 222 . As illustrated in FIG. 13 , the position of the sleeve 244 defines the radial position of the working tool 220 and allows the working tool 220 to be twisted in a range of 0° to 360° both clockwise and counterclockwise in the radial direction along the longitudinal axis of the handle 212 , altering the position of the working portion 220 relative to the axis running the length of the handle 212 . Once the user determines the desired radial position of the working tool 220 , the sleeve 244 is turned counterclockwise until the distal end 254 of the sleeve 244 contacts a proximal end 256 of the working tool 220 , preventing the working tool 220 from being threaded further onto the neck 216 . The radial position of the working portion 220 is temporarily fixed until a new desired radial position is set. As Illustrated in FIGS. 14 and 15 , the adjustable dental tool 200 may include a variety of working portions 220 . Specifically, FIG. 14 is a perspective view of an embodiment of the adjustable dental tool 200 including the working portion 220 illustrated as a cement spatula head 258 . This embodiment includes the same remaining elements of the adjustable dental tool 200 illustrated in FIGS. 10-13 . Specifically, FIG. 15 is a perspective view of one other embodiment of the adjustable dental tool 200 including the working portion 220 that is illustrated as a pick head 260 . This embodiment also contains the same remaining elements of the adjustable dental tool 200 illustrated in FIGS. 10-13 . The scope of this disclosure may include embodiments including working portions 20 that may be both detachably connected to the neck 16 and may be irremovably connected to the neck 16 . This embodiment is not limited to the mirrors 22 shown in these illustrations but could include any working portions 20 . It is envisioned that the adjustable dental tool may be assembled as a kit including a single or plurality of handles 12 and a plurality of removable working portions 20 that can all be interchanged on the handle 12 . Each handle 12 may include a single complementary coupling portion 46 that is in engagement with the female or male coupling portion 38 of the clamp 32 or may include a plurality of complementary coupling portions 46 located on both ends of the handle 12 for engagement with a plurality of male coupling portions 38 or female coupling portions of a plurality of clamps 32 . The handle 12 , neck 16 and working portions 20 and, in particular, the ball 18 and socket 34 , should be made from a material that is fully autoclavable for sterilization purposes. Working portions 20 are not limited to the working portions 20 illustrated in the embodiments of the Figures. Additional working portions may include, but are not limited to, a flosser, explorers, periodontal probes, saliva ejectors, gauges, cheek retractors, ligature directors, band pushers, scalers, bracket placers, periodontal curettes, periosteal elevators, filling instruments, root tip instruments, waxing instruments, burnishers, carvers, cavity liners, cement spatulas, cleoid discoids, and excavators, by way of non-limiting example. Several benefits and advantages of the present invention over prior dental tools include adjustment capabilities of the head 14 relative to the handle 12 , and the orientation of the working portion 20 of the head 14 itself. An additional advantage is the uniform handle 12 that may receive a plurality of dental heads 14 allowing for the formation of kits including a plurality of handles 12 and dental heads 14 that are all interchangeable. FIGS. 16-21 illustrate various views of an adjustable dental tool 262 including a handle 264 and a head 266 that can be placed in a patient's mouth. Referring specifically to FIGS. 16A-C , the head 266 includes a neck 268 having an adjustable section 270 and a working portion 272 which is in the form of a mirror 274 according to this embodiment. As will be discussed in greater detail below, the adjustable section 270 can be bent and/or twisted to affix the head 266 and ultimately the working portion 272 , e.g. the mirror 274 , in a desired position. The head 266 additionally includes a male coupling portion 276 or female coupling portion on its proximal end 278 , which is a male threaded portion 276 in this embodiment. The distal end 280 of the handle 264 includes a complementary female coupling portion 282 or male coupling portion, which is a female threaded portion 282 in this embodiment that is in engagement with the coupling portion 276 of the head 266 . Referring specifically to FIGS. 17A-E , the neck 268 includes an adjustable section 270 that may be manipulated to adjust the position of the working portion 272 relative to the proximal end 278 of the head 266 . The adjustable section 270 may be of an accordion construction to allow bending capability anywhere along its length. FIGS. 17B , 17 C, and 17 E demonstrate the bending capabilities of the adjustable section 270 which may be bent in a range of 0° to 360° from the longitudinal axis of the handle 264 in all directions, altering the position of the working portion 272 relative to the proximal end 278 of the head 266 . FIG. 17D demonstrates the twisting capabilities of the adjustable section 270 which allows the head 266 to be turned in a range of 0° to 360° both clockwise and counterclockwise in the radial direction along the longitudinal axis of the handle 264 , altering the position of the working portion 272 relative to the axis running the length of the handle 264 . The adjustable section 270 may also be bent and twisted simultaneously. The material of the adjustable section 270 is rigid enough to withstand forces encountered in the oral cavity without distortion, but also is flexible enough for the operator to manipulate the head 266 to the desired angle with ease. As Illustrated in FIGS. 18-21 , the adjustable dental tool 262 may include a variety of working portions 272 . Specifically, FIG. 18A is a perspective view of an embodiment of the adjustable dental tool 262 including a working portion 272 illustrated as an excavator 284 . This embodiment includes the same remaining elements of the adjustable dental tool 262 illustrated in FIGS. 16A-C . Specifically, FIGS. 18B and 3C are perspective views of two other embodiments of the adjustable dental tool 262 including working portions 272 that are illustrated as a filling head 286 and a probe head 288 , respectively. Each of these embodiments also contain the same remaining elements of the adjustable dental tool 262 illustrated in FIGS. 16A-C . FIG. 19A illustrates an embodiment of the adjustable dental tool 262 including a handle 264 , a head 266 , and a neck 268 having an adjustable section 270 wherein the head 266 is irremovably attached to the handle 264 . The working portion 272 of the embodiment shown here is a root elevator 290 . Further, as seen in FIG. 19B , the adjustable dental tool 262 may have the same embodiment as in FIG. 19A with the same working portion 272 , except include a removable head 266 as in FIGS. 16A-C . The adjustable section 270 of the head 266 is included in both the embodiment with the removable head 266 and the embodiment wherein the head 266 is irremovably attached to the handle 264 . FIG. 20 includes all of the elements of the adjustable dental tool illustrated in FIGS. 16A-C and further illustrates an embodiment of the adjustable dental tool 262 where two working portions 272 , which in this embodiment are pick heads 292 , may be connected to a single handle 264 , one working portion 272 connected to each of the distal and proximal ends. The scope of this disclosure may include embodiments including working portions 272 that may be both detachably connected to the handle 264 and may be irremovably connected to the handle 264 . This embodiment is not limited to the pick heads 292 shown in this illustration but could include any two working portions 272 in any combination. It is envisioned that the adjustable dental tool may be assembled as a kit including a single or plurality of handles 264 and a plurality of removable working portions 272 that can all be interchanged on a handle 264 . Each handle 264 may include a single complementary coupling portion 282 that is in engagement with the female or male coupling portion 276 of the working portion 272 or may include a plurality of complementary coupling portions 282 located on both ends of the handle 264 for engagement with a plurality of male or female coupling portions 276 of a plurality of working portions 272 . The handle 264 and working portions 272 and in particular the adjustable section 270 of the neck 268 , should be made from a material that is fully autoclavable for sterilization purposes. Working portions are not limited to the working portions illustrated in the embodiments of the Figures. Additional working portions may include, but are not limited to, a flosser, explorers, periodontal probes, saliva ejectors, gauges, cheek retractors, ligature directors, band pushers, scalers, bracket placers, periodontal curettes, periosteal elevators, filling instruments, root tip instruments, waxing instruments, burnishers, carvers, cavity liners, cement spatulas, cleoid discoids, and excavators, by way of non-limiting example. Several benefits and advantages of the present invention over prior dental tools include adjustment capabilities of the head 266 in any of the angle of the neck 268 , the location of the bend in the neck 268 , and the orientation of the working portion 272 of the head 266 itself. An additional advantage is the uniform handle 264 that may receive a plurality of dental heads 266 allowing for the formation of kits including a plurality of handles 264 and dental heads 266 that are all interchangeable. The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

A dental tool may include a head that may include a working portion and a neck. The neck may include a first end and a second end, and the working portion may extend from the first end. A handle may include a clamp and a socket. The socket may be configured to receive the second end of the neck. The second end may pivot within the socket to move the working portion and the neck relative to the handle. The clamp may be adapted to selectively fix the second end relative to the handle.

BACKGROUND OF THE INVENTION The invention relates to a data processor which has interrupt in a central processing unit, an interrupt handler which signals a single interrupt vector, and multiple interrupt sources connected to an interrupt handler through a daisy-chain unit to exchange interrupt request signals and interrupt acknowledge signals[]. The interrupt handler communicates a read vector command to all interrupt sources in parallel, to allow transmission of an actual interrupt address vector. In particular, the various interrupt sources may be distributed among a plurality of individual daisy chains. Interrupt organizations have been around for a long time, but a need for further improvement and extension is still being felt. Such development may lie on various levels of quality and quantity, for which reason the present invention should in particular cater to: it should support a large number of different interrupt sources and/or interrupt causes, typically 200 or more; it should support a large number of different priority levels, typically 16 or 32; it should provide vector support to facilitate fast selection of an appropriate handler routine; it should be easily extendible in size; it should allow flexible allocation of interrupt priorities. it should require only a minimum of routing overhead. No system has been encountered that is capable of meeting all above requirements at an acceptable price/performance level. SUMMARY TO THE INVENTION In consequence, amongst other things, it is an object of the present invention to provide a data processor with an interrupt architecture that offers a comprehensive and versatile solution to the combinations of all above requirements. Now thereto, according to a first aspect, the invention includes an interrupt handler unit which communicates a "read vector" command to all interrupt sources in parallel, for thereupon allowing transmitting an actual interrupt address vector on a bus. In particular, the bus may be used for other transport types outside the interrupt procedure; this lessens hardware requirements. Advantageously, an interrupt default vector generator tails a daisy-chain unit. This feature avoids the development of blocked progress. Further advantageous aspects are recited in dependent Claims. BRIEF DESCRIPTION OF THE DRAWING These and other aspects and advantages of the invention will be described more in detail hereinafter with reference to the disclosure of preferred embodiments, and in particular with reference to the appended Figures that show: FIG. 1, an elementary embodiment of an interrupt architecture according to the invention; FIG. 2, a timing diagram of the interrupt mechanism; FIG. 3, a block diagram of the interrupt controller; FIG. 4, a block diagram of an interrupt source; FIGS. 5A-5D, four different interrupt source implementations; FIG. 6, a block diagram of an interrupt default vector generator; FIG. 7, a detailed example of an interconnection scheme; FIG. 8, an exemplary interconnection scheme; FIG. 9, an overview of the interrupt architecture; FIG. 10, the interrupt acknowledge daisy-chain and vector selection mechanism. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 shows an elementary embodiment of an interrupt architecture according to the invention. The block diagram contains the principal subsystems of an integrated circuit VLSI data processor. As shown, central processor unit 20 is attached to PI bus 30, as are an interrupt controller 22, interrupt sources 24 and 26, and interrupt default vector generator 28. In practice, the number of interrupt sources may be large: an envisaged system may have >20 such physical sources which collectively may generate >200 different interrupt causes, that may be distinguished by an associated unique or non-unique interrupt vector. As will be shown in FIG. 4 hereinafter, the physical interrupt sources are effectively ORED for presenting an interrupt request signalization on one of the INTREQ lines to interrupt controller 22, and chained likewise in series for receiving an interrupt acknowledge signalization, one for each ORED line, on the lower multibit line from interrupt controller 22. The number of these lines may be greater than 1, and the interrupt handler may decide which request is to be handled first, e.g. as based on a hierarchy, on a round robin schedule. Controller 22 further presents to all such sources an Interrupt -- Read -- Vector signal on line 32. The interrupt vector proper can be presented to the central processing unit 20 by the actually partly self-selected active source on overall bus 30. Preferably, this is the so-called PI-bus as disclused in PCT Application EP 94/01711. Further, the processor has been shown with an on-chip or off-chip memory 34, I/O subsystem 36, and a "various" subsystem indicated as 38, such as a control unit BCU, not part of the invention. Interrupt-generating devices would be arranged in the string 24-26. Preferably, the architecture should allow low-level as well as sophisticated interrupt sources. By way of non-limitative example, the processor may be a RISC-processor, and the number of ORED interrupt request lines may be equal to 16. Upon receiving an interrupt request, interrupt controller or handler 22 executes interrupt masking, and furthermore determines which one of possibly coexistent interrupts has highest priority. An appropriate one-bit signal indicates to central processing unit 20 the existence of a nonmasked interrupt. When central processing unit 20 requests to read the actual interrupt vector, the interrupt controller 22 generates an acknowledge signal on the particular line of the acknowledge bus, which corresponded to the ORED line which the source then choose, or even chooses at that instant. If an interrupt source accepts the actual acknowledge signal, it will generate the lower part of the interrupt vector, while the interrupt controller will generate the upper part. If under particular circumstances, the interrupt acknowledge signal is not accepted by any of the connected sources, but arrives at Interrupt Default Vector Generator 28, the latter will generate the lower part of the interrupt vector instead. Subsequently, the interrupt vector is applied to bus 30 for the central processing unit. Definitions CPU: the CPU is a processing unit on the IC. Interrupts are generated to interrupt the normal program flow to perform interrupt service routines. CPU -- INT[M-1 . . . 0]: this is the single CPU interrupt bus which consists of M lines, that connect the interrupt controller to the CPU. Interrupt controller: decodes the interrupt request from the various interrupt sources into CPU interrupt requests, and selects one out of possibly many (16) ORED REQUESTs. It also acknowledges the interrupts and generates the upper part of the interrupt vector. Interrupt default vector generator: generates the lower part of the interrupt vector if no interrupt source does it. Interrupt source: every module on the IC that may want to interrupt the CPU. A particular module may generate various different interrupts, on one or more ORED Request lines. INT -- REQ[N-1 . . . 0]: the N lines of the interrupt request bus connect the interrupt sources to the interrupt controller. INT -- ACK[N-1 . . . 0]: the N lines of the interrupt acknowledge bus run from the interrupt controller via the interrupt sources to the interrupt default vector generator. Each line INT -- ACK[x] correspond to an ORED interrupt request line INT -- REQ[x]. INT -- CLEAR: the interrupt status variable INT -- STATUS located in the interrupt source can be cleared by writing a `1` to the corresponding interrupt clear variable INT -- CLEAR. INT -- ENABLE: the interrupt enable variable INT -- ENABLE located in the interrupt source can be set to `1` to admit an interrupt to the interrupt request lines or to `0` to ignore it. INT -- MASK: the (optional) interrupt masking variable to mask the different interrupt request lines INT -- REQ[x]. INT -- MASK -- LEVEL: the (optional) interrupt masking level variable to mask all interrupt request lines INT -- REQ[x] below a certain level. INT -- PRIORITY[N-1 . . . 0]: the (optional) interrupt request line priority variables to facilitate varying the priority for each interrupt request line INT -- REQ[x] separately. INT -- RD -- VECTOR: this interrupt read vector line connects the interrupt controller to all interrupt sources. It is asserted by the interrupt controller when the CPU wants to read the interrupt vector INT -- VECTOR: first comes signal ACK, and thereafter the RD -- vector. INT -- SET: the optional interrupt status variable INT -- STATUS located in the interrupt source can be set by writing a `1` to the corresponding interrupt set variable INT -- CLEAR. INT -- STATUS: the interrupt status variable INT -- STATUS located in the interrupt source equals `1` if the source wants to interrupt the CPU, or `0` if the interrupt source does not want to interrupt. INT -- VECTOR: the CPU will read the interrupt vector variable to branch to the appropriate interrupt routine when it is interrupted. The interrupt vector variable is split into two 16-bit parts: INT -- VECTOR[31..16]: the upper part of the interrupt vector variable is always generated by the interrupt controller; INT -- VECTOR[15..0]: the lower part of the interrupt vector can be generated by the various interrupt sources or by the interrupt default vector generator. L: the number of bus clock cycles required for the daisy-chained interrupt acknowledge signal to run through all interrupt sources (and back to the interrupt controller). M: the CPU dependent width of the CPU interrupt bus. Generally, M=1. N: the width of the interrupt request bus. Typically N equals 16 or 32. Also, N is the number of INT -- ACK lines. PI-bus D: these lines are the data lines of the bus. PI-bus CLK: this is the clock signal of the bus. Variables in the Interrupt Sources and the Interrupt Controller The variables are part of registers that can be read and written via the bus. The addresses of the registers are mapped within the bus address range, allocated to the particular interrupt source or the interrupt controller. Each interrupt source has a number of variables. There is a set of variables (INT -- STATUS, INT -- ENABLE, INT -- CLEAR and optionally INT -- SET) for each interrupt it can generate, and usually another set of variables will control the further behaviour of the device containing the interrupt source. Also one or more INT -- VECTOR[15..0] variables or constants can be part of an interrupt source. The interrupt controller has a number of variables such as INT -- VECTOR[31..16], and further variables for masking and priority decoding. The address of the total interrupt vector INT -- VECTOR is mapped in the address range allocated to the interrupt controller. The interrupt default vector generator may have a programmable default INT -- VECTOR[15..0] variable. If so, the address thereof is mapped in the address range allocated to the interrupt default vector generator. Requesting an Interrupt When an interrupt source has an (internal) interrupt request, it writes a `1` to the corresponding INT -- STATUS variable. If also the corresponding INT -- ENABLE variable equals `1`, the request is sent to the interrupt controller via the interrupt request line INT -- REQ[x] this particular interrupt is connected to. If the INT -- ENABLE variable equals `0`, the internal request is ignored. It is only sent to the interrupt controller, when INT -- ENABLE has been set to `1`. Masking and Prioritising The implementation of masking and prioritising are not specified. There is no explicit order among the N interrupt request lines INT -- REQ[N-1 . . . 0] and the M CPU interrupt lines CPU -- INT[M-1 . . . 0]. The priority decoder may be fixed in hardware or may be programmable. The masking feature is not a strict prerequisite. The simplest implementation of the masking and prioritising is by a strict and fixed hierarchy. Another solution is to implement an N-bit interrupt mask register, each bit of the register masking one interrupt request line. When a bit of the interrupt mask register equals `1`, the corresponding interrupt request line is enabled and when the bit equals `0`, the corresponding interrupt request line is disabled. A third solution is to implement an interrupt mask level register. Only interrupt request lines with a rank at least equal to the value of the interrupt mask level register are enabled, the others are disabled. Prioritising can be done by implementing a priority variable for each interrupt request line, so that the priority for each interrupt request line INT -- REQ[x] can be set separately. Combinations of the above are feasible as well. Other ways of deciding on the highest priority are often feasible, such as round robin. Interfacing with the CPU The way in which the N interrupt request lines INT -- REQ[N-1 . . . 0] are connected (after masking and prioritising) to the M CPU interrupt lines CPU -- INT[M-1 . . . 0] is implementation specific. Usually, M=1 is sufficient. When the CPU is interrupted, it may perform some specific actions such as context saving, and then it branches to an interrupt vector. In the end, the software branches to the interrupt handler, using the interrupt vector INT -- VECTOR as an offset to a branch table base address: this is fast, because no further processing is necessary on various specific bits from the INT -- VECTOR, the interrupt handler, or the actual source. Generating the Acknowledge and Getting the Interrupt Vector The interrupt vector INT -- VECTOR is addressed as a bus register, mapped on the address area allocated to the interrupt controller. If the interrupt controller receives a bus read request for the interrupt vector, it will select an acknowledge signal associated to REQ and its priority mask; an active source will subsequently self-select according to the daisy chain, (or the interrupt default vector generator) and via one interrupt acknowledge line, and will request the interrupt source (or the interrupt default vector generator) to put the lower part of the interrupt vector (INT -- VECTOR[15 . . . 0]) on the PI-bus D-lines. The upper part INT -- VECTOR[3l . . . 16] is always generated by the interrupt controller itself. The interrupt controller will latch the current value of the interrupt request lines, before or after masking and prioritising. Only the active interrupt request line with the current highest priority, depending on the masking and prioritising schemes, will be answered with a daisy-chained interrogation signal on its corresponding interrupt acknowledge line. Other interrupt request lines will remain unanswered for the moment. The daisy-chain starts running through the interrupt sources connected to the asserted interrupt acknowledge line. If more than one interrupt source generated a request on the selected interrupt request line, the daisy-chain takes care that only one of the interrupt sources gets the acknowledge. This will be the interrupt source connected logically closest to the interrupt controller. Other sources located `downstream` get blocked from the acknowledge. This leads to an implicit scheme of sub-priorities for each pair of interrupt request and acknowledge lines. The interrupt source wired closest to the interrupt controller has a higher sub-priority within the daisy-chain. Some delay is introduced to give the acknowledge signal enough time to run through the daisy-chain. During this delay the interrupt controller will drive the bus acknowledge ACK-lines with the WAT-acknowledge. The delay is equal to L bus clock cycles, synchronous to the rising edge of the bus clock CLK. The exact number of bus wait cycles is governed by the delay in the daisy-chained interrupt acknowledge lines and depends on the implementation. After this delay, the interrupt controller will assert the interrupt read vector signal INT -- RD -- VECTOR during the last WAT-acknowledge (because the INT -- RD -- VECTOR signal is an early signal) and drive the bus ACK-lines with the RDY-acknowledge instead of with the WAT-acknowledge. In this cycle, the interrupt controller will also put bits 31 to 16 of the interrupt vector INT -- VECTOR[31 . . . 16] on the bus while bits 15 to 0 of IN -- VECTOR[l5 . . . 0] will be driven by either the acknowledged interrupt source or by the interrupt default vector generator. The interrupt controller quasi "freezes" acknowledgement of new interrupts during the reading of the vector to avoid possible race conditions. The upper part of the interrupt vector, INT -- VECTOR[31 . . . 16], may contain the priority signalization, and is always generated by the interrupt controller. There are many different lower parts of the interrupt vector INT -- VECTOR[15 . . . 0], from at least one (in the interrupt default vector generator) to as many as one for each interrupt. Clearing the Interrupt Request When the interrupt request has been serviced by an interrupt routine, the interrupt source can be cleared by writing a `1` to the corresponding INT -- CLEAR variable. It is not recommended to clear the INT -- STATUS variable by writing a `0` to it, since a read-modify-write action might interfere with the hardware changing other bits in the same register. FIG. 2 is a diagram of the full timing mechanism of the architecture. The signal INT -- REQ[x] is asynchronous, the signal INT -- RD -- VECTOR is synchronous with the bus CLK. The successive traces show the following signals: the system bus clock, the bus read operation, the bus Operation code, the bus Address signalization, in particular the address contained in the interrupt vector, the bus Data slots, of which the final one transmits the Interrupt vector , the bus acknowledge, that has four wait cycles, followed by a single acknowledge cycle, the interrupt request signalization, the CPU interrupt signalization, the interrupt acknowledge, the interrupt acknowledge return (no signalization), and finally, the interrupt read vector. The vertical wave lines denote intervals of appropriate size. Signals INT -- REQ[N-1 . . . 0] connect the interrupt sources to the interrupt controller. No order or priority is specified. Interrupt sources are hooked up to these lines by means of OR-gates. Each interrupt source can connect to one or more interrupt request lines. The interrupt request lines are asynchronous and active high. INT -- ACK[N-1 . . . 0]: each interrupt acknowledge line INT -- ACK[x] corresponds to one interrupt request line INT -- REQ[x]. The interrupt acknowledge lines are asynchronous and active high. When the CPU addresses the interrupt controller to read INT -- VECTOR, the controller activates exactly one of the interrupt acknowledge lines. Priority and masking schemes determine which acknowledge line will be activated. The interrupt acknowledge lines are daisy-chained through the interrupt sources that correspond with REQ. Any source can block the acknowledge signal for other interrupt sources `downstream` when it has an interrupt pending on the corresponding request line. INT -- RD -- VECTOR: the interrupt read vector line connects the interrupt controller to the interrupt sources that are capable to generate the lower half of the interrupt vector, including the interrupt default vector generator. When the CPU addresses the interrupt controller to read INT -- VECTOR, it is asserted by the interrupt controller after a delay of L-1 bus clock cycles. The interrupt read vector line is active high and synchronous to the bus clock CLK. CPU -- INT[M-1 . . . 0]: these M are the CPU interrupt lines, usually M=1, for connecting the interrupt controller to the CPU. When the interrupt controller receives one or more interrupt requests on the interrupt request lines INT -- REQ[N-1 . . . 0], it asserts one or more of the CPU interrupt lines (if not all REQs are masked). Which line(s) will be asserted depends on the masking and priority schemes and on the mapping to the CPU interrupt lines, which are all implementation specific. The active level and timing behaviour of the CPU interrupt lines are CPU dependent. PI-bus D: these lines are the PI-bus data lines. PI-bus CLK: this is the clock signal of the PI-bus. ACK=WAT (wait), ACK=RDY (ready), depending on actual situation. FIG. 3 is a block diagram of the interrupt controller. At the top right corner, the N interrupt request lines 302 arrive. After passing through the masking, prioritising and latching block 310, the N lines are mapped 308 to the M usually single (M=1) CPU interrupt lines 306. A bus read request for the interrupt vector is routed via the bus interface 318 to control block 314. This block controls the latching block 310, and the acknowledge generation block 312, which generates the proper daisy-chained interrupt acknowledge on line 304. After a delay of L-1 bus clock-cycles, the control block requests the upper vector block to put the interrupt vector INT -- VECTOR[31 . . . 16] data on the bus 322 D-lines in the next bus CLK cycle. At the same time, the control block 314 asserts the INT -- RD -- VECTOR line to request the lower vector block (in one of the interrupt sources or in the interrupt default vector generator) to put the INT -- VECTOR[15 . . . 0] data on the bus D-lines in the next PI-bus CLK cycle. In the interrupt controller, only the INT -- VECTOR variable is mandatory. INT -- VECTOR: this interrupt vector variable is read by the CPU by issuing a PI bus read request. The INT -- VECTOR variable is split into two parts. The upper 16 bits INT -- VECTOR[31 . . . 16] are always generated by the interrupt controller. The lower 16 bits INT -- VECTOR[15 . . . 0] are generated by either the acknowledged interrupt source or by the interrupt default vector generator. The interrupt vector variables INT -- VECTOR[31 . . . 16] in the interrupt controller can be fixed constants (read-only) or programmable (also writable). A different INT -- VECTOR[31:16] variable or constant may be selected according to decisions made by the masking or priority mechanism. The priority may be part of INT -- VECTOR[31:16]. INT -- MASK: an optional interrupt masking variable to mask the various interrupt request lines INT -- REQ[x]. Each bit INT -- MASK[x]=0 in this variable will mask the corresponding interrupt request line INT -- REQ[x]. INT -- MASK -- LEVEL: if an optional interrupt masking level variable is used to mask all interrupt request lines INT -- REQ[x] below a certain level, it is called INT -- MASK -- LEVEL. If this variable has a value of y, all interrupt request lines INT -- REQ[x] with x<y will be masked (if y=0, no interrupt request lines whatsoever will be masked). INT -- PRIORITY[N-1 . . . 0]: if the optional interrupt request line priority variables are implemented, these are called INT -- PRIORITY[N-1 . . . 0]. These variables typically have a width of four bits (for N=16) and facilitate setting the priority for each interrupt request line INT -- REQ[x] separately. FIG. 4 is a simple block diagram of an interrupt source. At the top right and left corners, the interrupt request line comes 402 in and goes out 406. If the incoming interrupt request line is active, the outgoing interrupt request line will also be active. If the incoming interrupt request line is not active, the outgoing interrupt request line may be active if the interrupt source has an (enabled) interrupt request available via OR 404. In the middle at the left and right sides of the interrupt source, the interrupt acknowledge line comes in 416 and goes out 414. The outgoing interrupt acknowledge line will only be active if the incoming interrupt acknowledge line is active and the interrupt source does not have an enabled interrupt request pending through AND 410. This AND is optional and need not be implemented if the interrupt source will not generate its own INT -- VECTOR[15 . . . 0] but makes use of the default vector INT -- VECTOR[15 . . . 0] generated by the interrupt controller. At the bottom of the picture, the bus interface 420 and the read vector line INT -- RD -- VECTOR input 422 are drawn. When the INT -- RD -- VECTOR line input is active, and the interrupt source does have an acknowledged interrupt request pending, the lower part of the interrupt vector INT -- VECTOR[15 . . . 0] will be put on the bus D-lines in the next bus cycle. The INT -- RD -- VECTOR line also is not implemented if the source does not generate its own INT -- VECTOR[15 . . . 0]. Each interrupt source will have three (and an optional fourth) 1-bit variables for each interrupt it can generate. It also has an optional INT -- VECTOR[15 . . . 0] variable. 1 INT -- STATUS: this variable equals `1` if the source wants to interrupt the CPU, or `0` if the interrupt source does not want to interrupt. This variable can be a separate register, a flip-flop, or it can be represented by a state in a (finite) state machine. The variable may be read by means of the bus for polling. Other variables in the same register can be changed by the hardware in the meantime. Clearing and setting the variable can be done via the INT -- CLEAR (and optional INT -- SET, such as for diagnostic purposes) variable. The address of the variable is mapped within the bus address range, allocated to the particular interrupt source. 2 INT -- ENABLE: this variable can be set to `1` to admit the variable INT -- STATUS to the interrupt request lines (via the OR-gate) or to `0` to ignore the INT -- STATUS variable and to disconnect it from the interrupt request lines. INT -- ENABLE can be read and written via the PI-bus. The address of the variable is mapped within the PI-bus address range, allocated to the particular interrupt source. 3 INT -- CLEAR: INT -- STATUS[b] can be cleared by writing a `1` to the corresponding INT -- CLEAR variable. Writing a `0` to this variable will be ignored. After writing a `1` to this variable, the variable will be reset to `0` automatically. The address of the variable is mapped within the bus address range, allocated to the particular interrupt source. 4 INT -- SET: this optional variable can be set to `1` by writing a `1` to the corresponding INT -- SET variable to be able to simulate an interrupt of this particular source. Writing a `0` to this variable will be ignored. After writing a `1` to this variable, the variable will be reset to `0` automatically. This variable is optional. The address of the variable is mapped within the PI-bus address range that is allocated to the particular interrupt source. INT -- VECTOR[15 . . . 0]: the lower 16 bits of the interrupt vector variable INT -- VECTOR are generated by the interrupt source 418. It does so after it receives a request on the read vector line INT -- RD -- VECTOR 422 and the particular interrupt has been acknowledged. The INT -- VECTOR[15 . . . 0] variable can be a fixed constant or a programmable register. If a fixed constant, its value is hard-wired. If a programmable register, the address is mapped in the PI-bus address range allocated to the interrupt source (a programmable INT -- VECTOR[15 . . . 0] variable in an interrupt source may be read via its local INT -- VECTOR[15 . . . 0] address located in the interrupt source). Generally, the two least significant bits should always be zero to allow its usage as a 32-bit address word, used as offset in a table. This variable is optional; by default the interrupt default source will generate the lower 16 bits of INT -- VECTOR. For brevity, detailed mapping of the above variables and other items within the interrupt source, have not been specified here. A separate PI-bus address may be formed by adding or combining in one or more addressable registers. For any interrupt source, all interrupts may either be connected to the same interrupt request line INT -- REQ[x] or connected to different interrupt request lines. See FIGS. 5A and 5B, that through OR-gates illustrate various implementations. Approach B is more flexible. The various interrupt requests can be chained on one interrupt request line if desired, FIG. 5C. It is allowed to make the interrupt request line programmable, if the correct mapping to the interrupt acknowledge lines is multiplexed, FIG. 5D. Simple interrupt sources can be clustered and combined into one larger interrupt source to reduce cost on the bus interface, the request and acknowledge mechanisms and the INT -- VECTOR[15 . . . 0] variable. Any interrupt source should have at least one line, but no more than the interrupt handler can handle. For each interrupt request line INT -- REQ[x], one interrupt acknowledge line INT -- ACK[x] may or may not be implemented. FIG. 6 is a block diagram of the interrupt default vector generator. At the left side, the interrupt acknowledge lines INT -- ACK[N-1 . . . 0] 602 come in. At the bottom of the picture, the PI-bus interface 608 and the read vector line INT -- RD -- VECTOR input 610 are drawn. When the INT -- RD -- VECTOR line input and an INT -- ACK[x] are active, the lower part of the interrupt vector INT -- VECTOR[15 . . . 0] 606 will be put on the PI-bus D-lines in the next PI-bus 612 cycle by the interrupt default vector generator. INT -- VECTOR[15 . . . 0]: these are the lower 16 bits of the (default) interrupt vector variable INT -- VECTOR that are generated by the interrupt default vector generator. It does so after it receives a request on the read vector line INT -- RD -- VECTOR and an INT -- ACK[x] is active. All details are the same as for the INT -- VECTOR[15 . . . 0] variable inside the interrupt sources. An array of N different INT -- VECTOR[15 . . . 0] variables may be implemented, e.g. one for each incoming INT -- ACK[x] line, so that a different interrupt vector can be generated for each priority level. The interrupt default vector generator can be clustered with the interrupt controller, such as to reduce cost. The only requirements for the CPU are that it has enough interrupt inputs to connect to the CPU interrupt lines CPU -- INT[M-1 . . . 0] and that it can issue a bus read request to read the interrupt vector INT -- VECTOR. This read request may be issued directly by the CPU hardware or via an interrupt routine in software. Interconnection There are a number of requirements to the interconnection scheme for the CPU, the interrupt controller and the various interrupt sources. Interrupt request lines INT -- REQ[x] may not be split. They are all point-to-point connections between either: the INT -- REQ[x] output and the INT -- REQ[x] input of two different interrupt sources the INT -- REQ[x] output and another INT -- REQ[x] input of the same interrupt source, see FIG. 5 the INT -- REQ[x] output of an interrupt source and the INT -- REQ[x] input of the interrupt controller. When for an interrupt source, an interrupt request line INT -- REQ[x] input is connected, the INT -- REQ[x] out put must also be connected. The INT -- REQ[x] input of the first interrupt source in a chain will be connected to a logical `0` level. Interrupt acknowledge lines INT -- ACK[x] may not be split. They are all point-to-point connections between either: the INT -- ACK[x] output and the INT -- ACK[x] input of two different interrupt sources; the INT -- ACK[x] output and another INT -- ACK[x] input of the same interrupt source; the INT -- ACK[x] output of the interrupt controller and the INT -- ACK[x] input of an interrupt source; the INT -- ACK[x] output of an interrupt source and the INT -- ACK[x] input of the interrupt default vector generator; the INT -- ACK[x] output of the interrupt controller and the INT -- ACK[x] input of the interrupt default vector generator. When for an interrupt source, an interrupt acknowledge line INT -- ACK[x] output is connected, the INT -- ACK[x] input and output also have to be connected. The INT -- ACK[x] output of the last interrupt source in a chain will be routed to the corresponding INT -- ACK[x] input of the interrupt default vector generator. Every interrupt source is connected to at least one interrupt request line INT -- REQ[x] and at most all interrupt request lines. For each INT -- REQ[x] line, there must be a corresponding INT -- ACK[x] line. Even if no interrupt sources are connected to this INT -- ACK[x] line, it must be routed to the interrupt default vector generator to enable the generation of the default INT -- VECTOR[15 . . . 0] by the interrupt default vector generator. The interrupt default vector generator must be connected to all INT -- ACK[N-1 . . . 0] lines. Every interrupt source can be connected to from one to all interrupt acknowledge lines INT -- ACK[x]. Interrupt sources that will not generate INT -- VECTOR[15 . . . 0] do not have to be connected to the interrupt acknowledge lines INT -- ACK[x]. Interrupt sources that will generate INT -- VECTOR[15 . . . 0] have to be connected to the interrupt read vector line INT -- RD -- VECTOR. Interrupt sources that will not generate INT -- VECTOR[15 . . . 0] do not have to be connected to the interrupt read vector line INT -- RD -- VECTOR. Also the interrupt default vector generator has to be connected to the INT -- RD -- VECTOR line. The interrupt controller, all interrupt sources and the interrupt default vector generator must be connected to the PI-bus. The CPU interrupt lines CPU -- INT[M-1 . . . 0] are connected by the CPU interrupt line outputs of the interrupt controller to the interrupt inputs of the CPU. FIG. 7 is a feasible interconnection scheme. Here, N=4 and M=1. There are four interrupt request lines INT -- REQ[3 . . . 0] and also four interrupt acknowledge lines INT -- ACK[3 . . . 0]. The way in which various interrupt sources may be interconnected is listed in FIG. 8. Further, all interrupt sources, the interrupt controller and the interrupt default vector generator are connected to the interrupt read vector line INT -- RD -- VECTOR and the PI-bus. The CPU has not been shown, but the CPU interrupt bus consists of only one line CPU -- INT. Note that source C in this case is not connected to INT -- ACK[x], but obviously relies on the effective generation of the default vector. FIG. 9 summarizes of the interrupt architecture, in particular, the operation of the interrupt controller core INTC, viz a viz the many possible sources of interrupt. Entering at right are 32 request lines 918, each representing a priority level. The information on these can be latched in latch 904. Mask register 906, bitwise ANDED in AND 902, forwards to priority determining element 908 and coder 903. The coder codes to six bit signal CPU -- INT[5:0] on line 920, although one may be enough. The priority determined, acknowledges on 32 acknowledge lines 909, that are stringed through respective sources 910, 912, . . . 914, that collectively get a further control signal 911 from the core. As shown, the sources send signals to the request line channel, as well as to the system bus 916. The processor, when receiving the six-bit interrupt code,will, regardless the interrupt source, self-reliantly set the handling instant. It then will save status, and branch to an interrupt routine. Then the processor will issue a bus read for the interrupt vector: this is an address, and the interrupt controller will latch the currently highest interrupt level and generate a daisy-chain interrogate to the sources connected to that level. The interrupt source, after the daisy-chain delay, will put its vector on the bus. Then the controller puts an ACK=OK on the bus ACK lines. The processor can now use the value actually received as an address offset to determine on further actions. In this manner a two dimensional array wise interrupt is realized, wherein both the physical interrupt sources and also their respectively generated interrupts may have independent values. In the source, there are various variables: INT -- X signals that an interrupt is present (1) or not; this may be a flipflop. The flipflop is reset by writing to a PI-bus mapped address in the PI-bus range allocated to the unit of which this interrupt source is a part. further, ENAB -- X signals (1) to admit INT -- X on the appropriate INT -- REQ(L) line; this may be another flipflop, that can be read and written via the bus. Its address is in the bus range located to the unit of which this source is a part. FIG. 10 shows an examplary interrupt acknowledge daisy-chain and vector selection mechanism for one particular interrupt source. At the top are the interrupt controller core bundle 1002 (=909) and the system bus 1004 (=916). From left arrive the bit INT -- REQ -- X and the interrupt acknowledge INT -- ACK -- IN. The latter is inverted in element 1016 for activating latch 1008, thereby latching INT -- REQ -- X. If a `0` is stored, the inverted latch output opens AND gate 1014, thereby allowing INT -- ACK -- OUT to travel further to the right. If a `1` is stored, AND 1014 is blocked, but AND 1010 is opened, subject to receiving a further `1` from the interrupt controller core, thereby activating buffer 1012. This then puts the interrupt vector on the bus.

A data processor, includes a central processing unit, an interrupt handler for selectingly signalling a single interrupt vector to the central processing unit, and multiple interrupt sources that are daisy-chained to the interrupt handler, for therewith exchanging interrupt request signals and interrupt acknowledge signals. A Bus (or buses) interconnects all above subsystems. The interrupt handler communicates a read vector command to all interrupt sources in parallel and thereupon allows transmitting an actual interrupt address vector on the bus.

FIELD OF THE PRESENT INVENTION [0001] The present invention relates to the method of recycling wasted printed-circuit-board, particularly for the method and equipment thereof in collecting the different metals remaining on the recyclable wasted PCB being converted into recycling industrial materials under the standard of avoiding second pollution. BACKGROUND OF THE INVENTION [0002] As everyone knows, the PCB has been largely used in variety of electric products; Worryingly, the heavy metals in the wasted PCBs such as tin, lead and copper etc. can easily cause second social effects of pollution if those wasted PCBs did not collected for recycling or disposed unsuitably when they are discarded as junk; Especially, the brominated epoxy resins of halide in said wasted PCBs are much easier to spoil natural environment; that is why all the environmental protection experts of every country in the world without exception strive for advocating in reducing the utility rate of using halide materials. [0003] Therefore, every country in the world takes the wasted PCBs into noxious entrepreneurial junk under the environmental protection control; Presently, the relating industries already developed some methods to collect and recycle the metal materials and the fiberglass of intermediate material in the wasted PCB, they are comminuting method [for example: the patent numbers of 247281 and 363904 in the patent publication of TAIWAN R.O.C.], direct incinerating method, heating decomposition method, chemical dissolving method and melted inorganic salt method; However, while recycling disposal of the wasted PCB, some drawbacks still exist in these methods aforesaid as bellow. [0004] 1. Comminuting Method: [0005] First pulverize the wasted PCBs into powder, then sort said powder into two categories of more metallic powder and less metallic powder; Regardless of what kind of powder aforesaid, the ingredients contain mixture of brominated epoxy resins and fiberglass in addition of the metal so that causing not only impurity effect but also certain difficulty in recycling disposal; Especially, both of the recycling value of said brominated epoxy resins and fiberglass after collecting are neglected. [0006] 2. Direct Incinerating Method: [0007] Directly incinerate and melt the wasted PCBs into mixture of fiberglass and metal, then extract the essential metals after cooling; The process not only consumes much energy but also creates environmental pollution issue owing to the toxic hydrogen bromide [BrH] byproduct; Besides, the collected materials, which are low-grade mixture of metal, must re-smelt to purify for recycling use so that the value of direct utilization is very low. [0008] 3. Heating Decomposition Method: [0009] A tremendous amount toxic hydrogen bromide [BrH] gas is produced during heating decomposition process so that seriously jeopardizing natural environment; Excepting the metal being recyclable by sorting, the rest materials such as brominated epoxy resins and fiberglass are not recyclable with potentiality of spoiling environment. [0010] 4. Chemical Dissolving Method: [0011] The metal in the middle layers of the wasted PCBs can not be completely dissolved during dissolving process so that the brominated epoxy resins being mixed up with heavy metals after dissolving process; Thus, the issue of environmental protection still exists. [0012] 5. Melted Inorganic Salt Method: [0013] Collect and recycle metals and fiberglass by putting the wasted PCBs into melted inorganic salt, which having drawbacks as below: [0014] a. Upon processing temperature over 400° C., the tin, lead and copper in said wasted PCBs will mix into alloy such that becoming low-grade metal mixture, which not only incurring extra cost expense but also wasting time and effort for refinement. [0015] b. The wasted PCBs will float on the melted inorganic salt as the specific weight of the melted inorganic salt is greater than that of the wasted PCBs; Thereby, the agitating separation process is difficult to directly operate. [0016] c. The agitating shattering process will fail as the wasted PCBs softening with flexibility after the dissolution of the melted inorganic salt. [0017] d. The finished PCBs are interconnected by electroplating joint with soldering point being bigger than through-hole such that fiberglass of PCBs being tightly bonded; Thereby, the effect in separating process of fiberglass is relative low due to difficulty. [0018] e. The fiberglass will be ruined as the wasted PCBs being put in the melted inorganic salt over a long period of time; The collecting of said fiberglass is difficult as operating time in the mix-agitating process and the re-extracting process is uncontrollable and inconsistent; [0019] Meanwhile, the recycling feasibility of shattered fiberglass is relatively reduced. [0020] Accordingly, all the conventional methods aforesaid in disposing wasted PCB are not the ideal perfect disposal method. Therefore, the present invention originates a stepwise way to collect and recycle different materials by different method and step at each stage in accordance with the characteristics of the PCB so as to achieve in creating the best recycling value in consequence of perfect collecting and recycling. SUMMARY OF THE INVENTION [0021] The present invention originates a method of recycling wasted printed-circuit-board, whose prime object is to stepwise collect and recycle different materials in the wasted PCB in manner from outer towards inner way in accordance with the structural characteristics of the PCB; Additionally, a suitable recycling procedure is designed in accordance with recycling value such that recycling material obtaining highest recycling value; Thereby, an integrated recycling system is worked out for the everlasting plan in PCB industry. [0022] In other words, the present invention takes advantage of the characteristics of the PCB so as to dispose different recycling material in stage manner, so that different metals remaining on said PCB are sorted out step by step; Thereby, the bromide and the fiberglass of importance in the resins are collected and converted into variety of industrial materials as resource for recycling in order to prevent said wasted PCB from spoiling the natural environment after recycling. BRIEF DESCRIPTION OF THE DRAWINGS [0023] FIG. 1 is the disposal flow chart of the present invention. [0024] FIG. 2 is the illustrative view of the wasted PCB after chemical reaction in the melted sodium nitrate of the present invention. [0025] FIG. 3 is the illustrative view of the recycling equipment thereof to operate in coordination with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0026] As shown in the figures of number 1 and 2 , the present invention is a method of recycling wasted printed-circuit-board with disposal steps comprising: [0027] a. Remove all electronic components on all wasted PCBs 10 by heating them on their soldering points such that becoming wasted PCBs without any electronic component then collectively sort and dispose them for recycling use. [0028] Heat all such wasted PCBs without any electronic component over to 200° C. to melt soldering tin on their surface layer so as to remove and collect the tin-contained-compounds, whose melting point being 200° C.; then directly collect them by vacuum tin-sucking method for recycling use. [0029] c. Soak said wasted PCBs at step b in de-tin solution of market finished product to dissolve the tin-contained-compounds in the inner layers to separate it from copper; then directly collect all of tin-contained-compounds by said de-tin solution for recycling use. [0030] d. Apply strong acid solution on said wasted PCBs at step c to dissolve the spot-welding copper and electroplating copper in the through-hole out such that becoming wasted PCBs without any copper foil; Wherein, used strong acid solution will become acid solution containing copper ion [Cu ++ ] being able to serve as etching solution, and some copper pathways in the inner layers still mix up with fiberglass owing to no contacting with said strong acid. [0031] e. Soak said wasted PCBs at step d in melted sodium nitrate 20 to proceed heating decomposition chemical reaction to separate brominated epoxy resins from fiberglass so as to produce sodium bromide 11 , carbonized fiberglass 12 , copper foil 13 , organic gas 14 and nitrogenous oxides 15 ; [0032] Wherein, said sodium bromide 11 can be directly discharged and collected due to harmless to environmental safe, and said organic gas 14 and nitrogenous oxides 15 will become stable nontoxic gas to be discharged out after complete combustion. [0033] f. Separate carbonized fiberglass 12 and copper foil 13 by applying water rinsing method on their mixture formed above; then directly collect said carbonized fiberglass and copper foil for recycling. [0034] Wherein, the strong acid solution used in step d aforesaid can be the diluted nitric acid, either hydrochloric or sulfuric acid mixing with a little nitric acid to sprinkle on said wasted PCBs under oxygen environment. [0035] Furthermore, the detail of step d aforesaid is shown in the FIG. 2 ., employ melted sodium nitrate 20 to directly decompose brominated epoxy resins such that sodium ion [Na + ] and bromine ion [Br − ] immediately combining into stable sodium bromide 11 ; Thus, air pollution and environment pollution can be prevented by discharging said bromide out with gas. After heating decomposition, said epoxy resins will becomes organic gas 14 and black carbon, which adhering to the fiberglass 12 . Additionally, the sodium nitrate 20 becomes a nitrate radical ion [NO 3 − ] due to losing its sodium ion [Na + ]; both of said organic gas 14 and nitrate radical ion [NO 3 − ] will become stable gas after oxygenated combustion; Next, the toxic material contained can be easily removed via operating in coordination with water rinsing dirt-removal device; Thus, not only the bromine element can be collected for recycling use but also the carbonizing of the fiberglass can be enhanced as said fiberglass must via carbonizing reinforcement and increasing surface area to have application convenience for being favorable in recycling use. [0036] Moreover, after water rinsing method in the step f aforesaid, in the mixture of said carbonized fiberglass 12 and copper foil 13 , said carbonized fiberglass 12 will float upwards on the water solution while said copper foil 13 will precipitate downwards due to different specific weight comparing to that of water solution respectively; Thereby, the collecting and recycling process of carbonized fiberglass 12 and copper foil 13 becomes easier. [0037] Thus, via all the process steps aforesaid applying on said wasted PCBs 10 , all the constituents of the soldering tin, copper, brominated epoxy resins and fiberglass can be easily separated respectively; [0038] Hence, we can adequately work out solutions for both of pollution preventing and product recycling issues through above separating process. Comparing to all conventional process methods of prior art mentioned above, the process method of the present invention has following advantages: [0039] 1. Being a nondestructive manner, the process of the present invention has good economical effect as not incurring any recycling cost increase due to destroying material chemical structure. [0040] 2. Each process step of the present invention has recycling value effect in easy feasibility and resulting in not only substantially reducing the equipment investing cost but also being simple and convenient in operation. [0041] 3. The entire recycling process of the present invention can ensure in avoiding and preventing second pollution with reasons as bellow: (1) The nitric acid de-tin solution and hydrochloric acid de-tin solution used in the tin dissolving process is existing market finished product with mature process effect. (2) The strong acid used in the copper dissolving process is same as the etching solution used in the conventional PCB manufacturing process so that it can be directly collected to serve as etching solution for recycling use. (3) Employ strong oxidizing agent to directly decompose brominated epoxy resins such that sodium ion [Na + ] and bromine ion [Br − ] immediately combining into stable bromide and resulting in preventing second pollution. (4) The black carbon, attaching on the fiberglass with intact large surface area after heating decomposition, not only make itself increase in the recycling feasibility and process easiness but also make said fiberglass save heating energy in carbonization for being directly collected as recycling material. (5) The fiberglass can be easily collected and recycled via simple water rinsing method. (6) The copper foil can be easily collected and recycled via simple water rinsing method too. (7) Separating the sodium bromide and sodium nitrate is not difficult owing to their difference in physical properties, namely the melting point is 300° C. and specific weight is 2.261 for said sodium nitrate while the melting point is 757.7° C. and specific weight is 3.203 for said sodium bromide. (8) All the variety of recycling materials can create good recycling value without any waste in the process. [0050] Regarding the method for undertaking the heating decomposition in providing said wasted PCBs 10 and sodium nitrate 20 , the equipment thereof in recycling wasted printed-circuit-board in the present invention comprises a furnace 30 and a heater 40 ; Wherein, said furnace 30 comprises a feeding inlet 31 , a discharge valve of sodium bromide 32 , an gas complete-combustion apparatus 50 and a production outlet 34 ; [0051] For said feeding inlet 31 with double doors design of exterior door and interior door has working safety in consequence of preventing internal gas from leaking out by means of their interlocking protection of said double doors; Whose operation way is that first put the wasted PCBs 10 , which containing brominated epoxy resins and fiberglass, together with the sodium nitrate 20 inside while exterior door being open and interior door being closed; next guide said wasted PCBs 10 and sodium nitrate 20 into said furnace 30 while exterior door being closed and interior door being open; then close the interior door after all feeding stuff getting into said furnace 30 such that double doors in closed status. [0052] Said discharge valve of sodium bromide 32 is to discharge the mixing liquid of said sodium nitrate 20 and sodium bromide 11 out of said furnace 30 after heating decomposition chemical reaction, wherein said sodium bromide 11 being at the undermost of said furnace 30 due to heavier specific weight than that of said sodium nitrate 20 ; [0053] Said outlet tractor of fiberglass 33 is to draw the carbonized fiberglass and copper foil to said production outlet 34 after heating decomposition chemical reaction, so that subsequently undertaking water rinsing outside of said furnace 30 via said production outlet 34 so as to obtain pure carbonized fiberglass 12 and pure copper foil; [0054] Said heater 40 is to heat said sodium nitrate 20 up to between 350° C. and 500° C. such that said sodium nitrate 20 becoming melted state. [0055] Thus, via all equipment aforesaid, heating decomposition chemical reaction of said wasted PCBs 10 and sodium nitrate 20 happens in said furnace 30 and the sodium bromide 11 , carbonized fiberglass 12 , copper foil 13 , organic gas 14 and nitrogenous oxides 15 are obtained respectively; Wherein, said sodium bromide 11 , fiberglass 12 and copper foil 13 are drawn out of the furnace 30 by said outlet tractor of fiberglass 33 such that removing said sodium bromide 11 and sodium nitrate 20 by water rinsing to obtain carbonized fiberglass 12 and copper foil 13 as industrial materials for recycling use; [0056] And, said organic gas 14 and nitrogenous oxides 15 will be converted into stable gas 141 after complete combustion in the gas complete-combustion apparatus 50 and water rinsing in the water rinsing dirt-removal device. As shown in the FIG. 3 , said gas complete-combustion apparatus 50 mainly comprises a circulating reactor 51 , an oxygenated combustion-supporting reactor 52 , an air reaction buffing retainer 53 , a second heating burner 54 , a blower 55 , an air heat-exchanger 56 , a furnace cooler 57 , an air dirt-removal cooler 58 and a pressure equilibrator 59 ; [0057] Wherein, said circulating reactor 51 , which being built in the furnace 30 , is to control the reaction time of said wasted PCBs 10 and melted sodium nitrate 20 by transmission speed of connected motor so as to ensure the quality of the fiberglass 12 not being spoiled; [0058] Said oxygenated combustion-supporting reactor 52 , which being put above said circulating reactor 51 in the furnace 30 , is to supply compressed oxygen so as to enhance the complete combustion of said organic gas 14 ; [0059] Said air reaction buffing retainer 53 , which being constructed above said oxygenated combustion-supporting reactor 52 in the furnace 30 , is to stabilize and expedite the gas inside in chemical combination with oxygen of hot air; [0060] Said second heating burner 54 , which being put above said air reaction buffing retainer 53 , is to increase the reaction temperature in the furnace 30 so as to ensure said organic gas 14 being combusted more completely during second combustion as well as to let air dirt-removal cooler 58 cool them down to become stable gas 141 meanwhile; [0061] Said blower 55 , which being disposed above the furnace 30 , is to inhale a great quantity of external air into said furnace 30 such that said organic gas 14 and nitrogenous oxides 15 complete combusting quickly so as to eliminate the incomplete combustion phenomena of those gas; [0062] Said air heat-exchanger 56 , which being built above said second heating burner 54 over the furnace 30 , is to warm and activate the intake cool air by temperature of said furnace 30 so as to have multiple enhancing effects as not only increasing the activity of oxygen for combustion but also reducing the consumption of fuel material as well as accelerating the reaction speed; [0063] Said furnace cooler 57 , which being put on the furnace 30 , is to exchange heat between the cooling water and the temperature of said furnace 30 under principle of heat exchange so as to cool down the temperature of said furnace 30 ; [0064] Said air dirt-removal cooler 58 is to remove the dirty material via dust-filtering and adsorption for the gas after combustion, which being then discharged outside after dirt-removal handling to prevent second pollution; [0065] Said pressure equilibrator 59 is to detect and measure the negative pressure in the furnace 30 by pressure transducer, then to adjust the speed of windmill via regulation of the frequency converter by means of pressure controller so as to further equilibrate the pressure in said furnace 30 such that said organic gas 14 being processed in single adequate direction; [0066] Therefore, concluding the exemplary embodiment aforesaid, it is justified that such gas complete-combustion apparatus 50 can really convert the organic gas 14 and nitrogenous oxides 15 into nontoxic stable gas 141 after heat decomposition; Thus, whole process absolutely conforms to every regulations of the environment protection as no harmful material being discharged out.

The present invention relates to a “method of recycling wasted printed-circuit-board”, which takes advantage of the characteristics of the PCB so as to dispose different recycling material in stage manner, so that different metals remaining on said PCB are sorted out step by step; Thereby, the bromide and the fiberglass of importance in the resins are collected and converted into variety of industrial materials as resource for recycling use in order to prevent said wasted PCB from spoiling the natural environment after recycling use.

This is a divisional application of Ser. No. 08/823,248, filed Mar. 24, 1997, now U.S. Pat. No. 5,718,966, issued on Feb. 17, 1998, which in turn is a continuation application of Ser. No. 08/328,835, filed Oct. 25, 1994, now abandoned. BACKGROUND OF THE INVENTION (1) Field of the Invention The present invention relates to reinforcing the edges of a fabric panel. More specifically, the present invention relates to a method of coating the edges of a release liner fabric to prevent raveling or fraying during cutting and subsequent use. (2) Description of the Prior Art Woven fabrics that are made from thermoplastic yarns tend to disassemble along the cut edge when cut and subsequently handled. This disassembly occurs as the result of the untangling of the warp and weft yarns and is commonly known as raveling. Raveling significantly reduces the efficiency of subsequent article handling operations such as winding and unwinding and shipping and seriously reduces the strength of the fabric at its edges. Release liners fabricated from fabrics with edges having untangled warp and weft yarns tend to pull apart when stressed during handling. This phenomenon is generally referred to as raveling. When this deficiency, particularly in strength, occurs in release liners for shipping rolled rubber sheeting for use in manufacturing tires, unacceptable damage to the release liner causes shorten life of the liner and possible contamination of the rolled rubber sheeting. Various physical procedures have been proposed and adopted to prevent edge raveling. These include fusing the warp and weft yarns along the cut edge by various means during the cutting process. Processes known to be commonly used in this regard are based on hot-die slitting and laser cutting methods. Generally, these methods are unacceptably slow or add significant costs to the production of the finished article. Fabric typically used for release liners in shipping rolls of calendared rubber sheeting for manufacturing tires for automobiles and other vehicles must satisfy a number of unique and demanding requirements. Fabrics that are useful for release liner construction are required to be strong, lightweight, resistant to abrasion and have good release from the rubber stock. Typically, conventional release liners meeting the above objectives are made of coated fabrics like siloxane-coated nylon or acrylic-coated polyester. In either case, the release liner fabric panel requires fabric edge reinforcement to provide longer service life. SUMMARY OF THE INVENTION The present invention is directed to a method for reinforcing the fabric edges of a release liner to prevent raveling or fraying of the yarns during use. To this end, the process is carried out by coating the yarn crossovers with a flexible, thin film of a radiation polymerized resin and then curing the coating system at high production speeds. Fabrics treated by the process of the present invention have a significantly reduced tendency to ravel during cutting, handling and use. Further, fabrics that are reinforced produce better end results in applications in which they are used as compared to fabrics that are not reinforced. For example, the process, which is based on high speed radiation curable resin coating, is particularly suitable for the fabrication of release liners used for the production of rolled rubber sheeting used in manufacturing tires made from fabrics such as nylon, polyester and polyolefin. Accordingly, one aspect of the present invention is to provide a method for reinforcing the edge of a release liner fabric. The method includes the steps of: (a) applying a thin layer of a radiation-curable resin to a pre-selected area of the edge of the fabric to be cut, the radiation-curable resin being curable and crosslinkable at substantially ambient temperatures; (b) irradiating the coated fabric of step (a) in at least those areas containing the radiation-curable resin under conditions to cure and crosslink the resin into a thin, flexible, nonreactive coating impregnating the fabric and securing the yarn crossovers together to prevent raveling; and (c) cutting the irradiated fabric in the coated areas thereby leaving the cut edge ravel-resistant. Another aspect of the present invention is to provide a release liner fabric having a reinforced edge. The release liner includes: (a) an elongated fabric panel; and (b) a thin layer of a radiation-curable resin applied to a pre-selected area of the edge of the fabric to be cut, the radiation-curable resin being curable and crosslinkable at substantially ambient temperatures. Still another aspect of the present invention is to provide a reinforced edge for a release liner fabric panel. The reinforced edge includes a thin layer of a radiation-curable resin applied to a pre-selected area of the edge of the fabric, the radiation-curable resin being curable and crosslinkable at substantially ambient temperatures, the resin being selected from the group consisting of polyfunctional acrylic monomers, acrylated urethane oligomers and acrylated urethane polymers. A final aspect of the present invention is to provide a release liner fabric having a reinforced edge. The release liner includes: (a) an elongated fabric panel; (b) a release finish uniformly coated on at least one of its entire surfaces of the fabric panel; and (c) a thin layer of a radiation-curable resin applied to a pre-selected area of the edge of the fabric to be cut, the radiation-curable resin being curable and crosslinkable at substantially ambient temperatures, the resin being selected from the group consisting of polyfunctional acrylic monomers, acrylated urethane oligomers and acrylated urethane polymers. These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment. DESCRIPTION OF THE PREFERRED EMBODIMENTS The inventors have found that coating compositions containing an initiator, polyfunctional acrylic monomers, acrylated urethane oligomers and acrylated urethane polymers in combination with other additives, produce radiation curable and crosslinked coatings which are highly effective in enhancing the ravel resistance of cut fabric edges without the shortcomings associated with the above-mentioned prior art. In practicing the present invention, the radiation curable coating compositions are first compounded by adding together the polyfunctional acrylic monomer or mixtures thereof, optionally an ultraviolet (UV) sensitizer, and optionally, any other additives. The various components are thoroughly mixed so as to form a generally homogeneous coating composition. A thin, uniform coating of the coating solution is then applied onto the fabric surface by any of the known means such as dipping, spraying, screen printing, rollcoating and the like. In the instant invention, screen or gravure applications are preferred. The coating is then cured (optionally in an inert, e.g., [nitrogen] atmosphere) using ultraviolet or, optionally, electron beam radiation. Preferably, UV radiation which can have a wavelength of from 1000 Å to 3900 Å is the most cost effective. In the present invention, the lamp systems used to generate such radiation can consist of ultraviolet lamps which can include discharge lamps, i.e., xenon, metallic halide, metallic arc, or mercury vapor discharge lamp, etc., having operating pressures of from as low as a few milli-torr up to about 10 atmospheres. Curing by exposure to an electron beam is also possible. The electron source may be gamma or pile sources, or electrostatic methods. For purposes of the present invention, curing is defined as the copolymerization of the polyfunctional acrylic monomers, acrylated urethane oligomers and polymers to form a flexible coating. The reaction chemistry of crosslinking through radiation induced polymerizations of, for example, UV-curable coatings, is generally known to those skilled in the art. In the practice of this invention, the UV curable coating is generally formed by, but is not restricted to, the polymerization of acrylated urethane oligomers. The principle components of the embodied coating materials for this application are of two main types. These are: 1. Resins. These may be oligomers or prepolymers. 2. Diluents. These may be: a. reactive monomers or oligomers. b. unreactive compounds that plasticize the cured film. Preferred materials should give a hard but flexible coating with good adhesion to various fabric substrates. The coating must have acceptable wetting and flow characteristics to provide for uniform application to fabric. Resin types generally used include: Unsaturated Polyesters Acrylated Polyesters Acrylated Epoxy Esters Acrylated Isocyanates Acrylated Triazines Acrylated Polyethers Thiol-ene Systems: Cationic cured epoxy systems Aminoplasts cured by photoliberated acids A preferred aspect of the invention is the use of acrylated polyurethane resin materials and reactive oligomers. Urethane resins may be prepared as follows from reactions of isocyanates with compounds containing hydroxyl groups such as alcohols: ##STR1## Unsaturation may then be readily introduced when R is acrylic, allylic, vinylic, et al. For example: ##STR2## More complicated urethanes may be prepared by reacting: ##STR3## Unsaturation may also be introduced by reacting a hydroxyl-modified acrylic or methacrylic monomer with a polyisocyanate to obtain a urethane-type resin containing acrylic linkages which can then undergo free-radical photopolymerization. Di-isocyanates are frequently used, allowing large structures to be formed, especially when the chain is lengthened by ethylene oxide derivatives, amino alcohols, polyesters, diamines, etc. as shown below. ##STR4## Very large complicated urethane structures may be built up by combinations with acrylics and polyester/urethane complexes, e.g., a polyester/acrylate may be based upon adipic acid (AD) and hexanediol (HD) reacted through its terminal hydroxyl groups with acrylic acid to give a structure of the form: ##STR5## and this same polyester acrylate may then be reacted with toluene-di-isocyanate (TDI), ##STR6## followed by further reaction with hydroxyethyl acrylate to give a possible structure of the form: ##STR7## Illustrative examples of other starting materials for synthesis of polyurethanes include optional di-isocyanates as shown in Table 1 and polyether polyols as shown in Table 2. The preceding overview of polyurethane chemistry is essentially that of Roffey, and is hereby incorporated by reference from Photopolymerization of Surface Coatings, C. G. Roffey, John Wiley & Sons: New York, pp. 153-156. TABLE 1______________________________________Representative Di-isocyanatesName Structure______________________________________PPDI 1 #STR8##TDI 2 #STR9##MDI 3 #STR10##PMDI 4 #STR11##NDI 5 #STR12##TODI 6 #STR13##XDI 7 #STR14##HDI OCN(CH.sub.2).sub.6 NCOTMDI 8 #STR15## 9 #STR16##CHDI 0 #STR17##BDI 1 #STR18##H.sub.6 XDI 2 #STR19##______________________________________ TABLE 2______________________________________Representative polyether PolyolsProduct Functionality______________________________________poly(ethylene glycol) (PEG) 2poly(propylene glycol) (PPG) 2PPG/PEG* 2poly(tetramethylene glycol) (PTMG) 2glycerol adduct 3trimethylolpropane adduct 3pentaerythritol adduct 4ethylenediamine adduct 4phenolic resin adduct 4diethylenetriamine adduct 5sorbitol adducts 6sucrose adducts 8______________________________________ *Random or block copolymers. The reactive monomers of the present invention are represented by the general formula (1): ##STR20## Where "n" is an integer from 1 to 8, preferably from 2 to 6, and more preferably from 2 to 4; and "R" is an "n" functional hydrocarbon, an "n" functional substituted hydrocarbon, an "n" functional hydrocarbon containing at least one ether linkage, an "n" functional substituted hydrocarbon containing at least one ether linkage. Preferred "n" functional hydrocarbons are the "n" functional aliphatic, preferably saturated aliphatic, hydrocarbons containing from 1 to about 20 carbon atoms and the "n" functional aromatic hydrocarbons containing from 6 to about 20 carbon atoms. Preferred "n" functional hydrocarbons containing at least one ether linkage are the "n" functional aliphatic hydrocarbons, preferably saturated aliphatic hydrocarbon residues, containing from 1 to about 5 ether linkages and from 2 to about 20 carbon atoms. Preferred "n" functional substituted hydrocarbons are the "n" functional aliphatic hydrocarbons, preferably the saturated aliphatic hydrocarbons, containing from 1 to about 20 carbon atoms, and the "n" functional aromatic hydrocarbons containing from 6 to about 10 carbon atoms which contain substituent groups such as the halogens, i.e., fluorine, chlorine, bromine and iodine, and/or substituent groups such as hydroxyl, --COOH, --COH and --COOR' groups wherein "R'" represents alkyl groups containing from 1 to about 6 carbon atoms. Preferred "n" functional substituted hydrocarbons containing at least one ether linkage are the "n" functional aliphatic, preferably saturated aliphatic, hydrocarbons containing from 2 to about 20 carbon atoms and from 1 to about 5 ether linkages which contain substituent groups such as the halogen hydroxyl, --COOH, --COH, and --COOR' groups wherein "R'" is as defined above. The more preferred polyfunctional acrylic monomers are those represented by Formula 1 wherein "R" is selected from the group consisting of an "n" functional saturated aliphatic hydrocarbon containing from 1 to about 20 carbon atoms, a hydroxyl substituted "n" functional saturated aliphatic hydrocarbon containing from about 1 to about 20 carbon atoms, an "n" functional saturated aliphatic hydrocarbon containing from 2 to about 20 carbon atoms and from 1 to about 5 ether linkages, and a hydroxyl substituted "n" functional saturated aliphatic hydrocarbon containing from 2 to about 20 carbon atoms and from 1 to about 5 ether linkages. The preferred polyfunctional acrylate ester monomers are those wherein "R" is an "n" functional saturated aliphatic hydrocarbon, ether, or polyether, with those monomers wherein "R" is an "n" function saturated aliphatic hydrocarbon being more preferred. More particularly, the di-functional acrylic monomers, or diacrylates, are represented by Formula 1 wherein "n" is 2; the trifunctional acrylic monomers, or triacrylates, are represented by Formula 1 wherein "n" is 3; and the tetrafunctional acrylic monomers, or tetra-acrylates, are represented by Formula 1 wherein "n" is 4. Illustrative of suitable polyfunctional acrylate ester monomers of Formula 1 are those listed below in Table 3. These polyacrylate esters and their production are well known to those skilled in the art. The preceding is incorporated by reference from U.S. Pat. No. 4,198,465 by Moore, et al. TABLE 3______________________________________Polyacrylates of Formula 11. CH.sub.2 ═CHCOO--CH.sub.2 --OOCCH═CH.sub.22. CH═CHCOO--CH.sub.2 --CH.sub.2 --OOCCH═CH.sub.23. CH.sub.2 ═CHCOO--CH.sub.2 --CHOHOCH.sub.2 --OOCCH═CH.sub.24. CH.sub.2 ═CHCOO--(CH.sub.2).sub.4 --OOCCH--CH.sub.2 1 #STR21##6. CH.sub.2 ═CHCOO--CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 --OOCCH═ CH.sub.2 2 #STR22## 2 #STR23## 3 #STR24##10. 4 #STR25## 5 #STR26## 6 #STR27##13. CH.sub.2 ═CHCOO--CH.sub.2 --CH═CH--CH.sub.2 --CH.sub.2 --OOCCH═CH.sub.2 7 #STR28## 8 #STR29## 9 #STR30## 0 #STR31## 1 #STR32## 2 #STR33##20. 3 #STR34## 4 #STR35##Triacrylates of Formula 1 5 #STR36## 6 #STR37## 7 #STR38## 8 #STR39## 9 #STR40## 0 #STR41## 1 #STR42##______________________________________ These polyacrylate esters and their production are well known to those skilled in the art. One method of producing the di-, tri-, and tetra-acrylate esters involves reacting acrylic acid with a di-, tri-, or tetrahydroxyl compound to produce the di-ester, tri-ester or tetra-ester. Thus, for example, acrylic acid can be reacted with ethylene glycol to produce ethylene glycol diacrylate (compound 2 in Table 3). Although the coating compositions may contain only one of said polyfunctional acrylate monomers, coating compositions may contain a mixture of two polyfunctional monomers, preferably a diacrylate and a triacrylate. When the coating compositions contain a mixture of acrylate monomers, it is preferred that the ratio, by weight, of the diacrylate to the triacrylate be from about 30/70 to about 70/30. Exemplary mixtures of diacrylates and triacrylates include mixtures of hexanediol diacrylate with pentaerythritol triacrylate, hexanediol diacrylate with trimethylolpropane triacrylate, diethyleneglycol diacrylate with trimethylolpropane triacrylate. While the corresponding coatings may likewise contain the ultraviolet light reaction product of a single polyfunctional acrylate monomer, coatings containing the photoreaction product of two polyfunctional acrylate monomers, preferably a diacrylate and a triacrylate, are preferred. Generally, the coating composition contains from about 40 to about 99 weight percent of the polyfunctional acrylate or acrylates. The UV cured coating contains from about 40 to about 99 weight percent of the photoreaction products of the polyfunctional acrylate monomer or mixture of acrylate monomers present in the coating composition. The photocurable coating compositions also contain a photosensitizing amount of photosensitizer, i.e., an amount effective to initiate the photocure of the coating composition. Generally, this amount is from about 0.01% to about 10% weight, preferably from about 0.1% to about 10% weight, and more preferably from about 0.1% to about 5% by weight of the photocurable coating composition. These additives and the cure thereof are generally well known in the art. Some non-limiting examples of these UV radiation photosensitizers include ketones, such as benzophenone, acetophenone, benzyl, benzyl methyl ketone, benzoins and substituted benzoins such as benzoin methyl ether, a-hydroxymethyl benzoin isopropyl ether; halogen-containing compounds such as o-bromoacetophenone, p-bromoacetophenone, and the like. The coating compositions of the present invention may also optionally contain various flame retardants, flatting agents, surface active agents, thixotropic agents, UV light absorbers and dyes. All of these additives and the use thereof are well known in the art and do not require extensive discussions. Therefore, only a limited number will be referred to, it being understood that any compounds possessing the ability to function in such a manner, i.e., as a flame retardant, flatting agent, surface active agent, UV light absorber, and the like, can be used so long as they do not deleteriously affect the photocuring of the coating compositions. The various surface-active agents, including anionic, cationic and nonionic surface-active agents are described in Kirk-Othmer Encyclopedia of Chemical Technology, Vol. 19, Interscience Publishers, New York, 1970, pp. 477-486, a reference incorporated herein. Accordingly, in the preferred embodiment, the method for reinforcing the edge of a release liner fabric according to the present invention includes applying a thin layer of a radiation-curable resin to a pre-selected area of the edge of the fabric to be cut, wherein the resin further includes an initiator. The radiation-curable resin is curable and crosslinkable at substantially ambient temperatures and selected from the group consisting of polyfunctional acrylic monomers, acrylated urethane oligomers and acrylated urethane polymers. After application by conventional means, the next step is irradiating the coated fabric in at least those areas containing the radiation-curable resin under conditions to cure and crosslink the resin into a thin, flexible, nonreactive coating impregnating the fabric and securing the yarn crossovers together to prevent raveling. Finally, the irradiated fabric is cut in the coated areas thereby leaving the cut edge ravel-resistant. The resulting stabilized fabric has three times the life of a comparable fabric without the edge treatment according to the present invention. In a most preferred embodiment, the fabric is coated with the radiation-curable resin in patterns defining a plurality of parallel bands extending lengthwise, irradiated and cut within the bands of irradiated resin to form release liners of predetermined widths. In one embodiment, the fabric is woven nylon and the fabric is uniformly coated on at least one of its entire surfaces with a siloxane release finish prior to being irradiated and cut to form said release liner. In another embodiment, the fabric is woven polyester and the fabric is uniformly coated on at least one of its entire surfaces with an acrylic release finish prior to being irradiated and cut to form said release liner. In either case the fabric may be cut with a reciprocating knife or other slitting means. In the preferred embodiment, the fabric is woven in a plain square weave. Also, preferably, the fabric is formed from warp yarn having a denier of between about 150 to 1000 and from weft yarn having a denier of between about 150 to 1000 wherein the fabric has a weight of between about 3 oz/yd 2 to 8 oz/yd 2 . In the preferred embodiment, the edge is between about 0.25 to 2.0 inches in width but because the resin wets the fabric, the resin does not form a thickened edge. This prevents "dumb belling" which would occur when the release liner is rolled if it had a thickened edge. By way of example and not limitation, the following examples serve to further illustrate the present invention in its preferred embodiments. EXAMPLE I Fabrics are rendered ravel-resistant by applying a thin, flexible polymerized coating at the edges thereof and in areas where raveling due to abrasion is likely to occur or where reinforcement is required. The process of this invention includes applying a liquid, radiation-curable resin system, in uncured or uncrosslinked form, pre-determined to selected areas of a fabric in a pattern matching or approximating the areas and shapes of the fabric to be cut. Conveniently, the fabric is in open width. Next, the applied resin system is exposed to the type of radiation needed to cure and crosslink the resin, depending upon the catalyst crosslinker, etc., system employed (see the following discussion), typically UV radiation. Once the liquid resin system is cured, it solidifies into a non-tacky coating and is preferably clear and transparent or substantially transparent. Next, the fabric is cut in the areas where the cured coating was applied. Cutting may be accomplished by any convenient means, including knife cutting. The area of the cut is aligned with or arranged to be within the coated area so as to leave a band or border of cured resin of sufficient width to prevent raveling of the nonselvage edge. The cut edge thus formed is resistant to raveling during use as a release liner for the separation of calendared rubber sheeting used for the production of tires and other molded rubber products. EXAMPLE II Another objective of this invention is to provide a procedure for preventing the cut edge of an otherwise uncoated fabric from raveling. The procedure is substantially as explained in Example I; that is, selecting the general area of a fabric that is to be cut, applying a radiation-curable coating, and curing and crosslinking the resin. Coating formulations representative of those described herein are given in Table 4. The compositions given in Table 4 are for a series of formulations whose performance is evaluated for their ability to strengthen the fabric edge by binding the warp and fill yarns together at the crossover points. A further requirement of these compositions is that they do not adhere to the rubber sheet stock against which the release liner comes in contact with during use. Included are the formulations for eight compositions which differ in the relative amounts of mono- and di-functional reactive diluents and the addition of a polysiloxane copolymer surfactant. Test results for the formulations in Table 4 are shown in Tables 5-8. These tests are representative of those which are of importance in many coated fabric applications, including release liners. The combout resistance data given in Table 5 is especially relevant to coatings applied for the purpose of ravel resistance. This data indicates a clear and dramatic increase in combout resistance, and hence, ravel resistance. The effect on weight gain, thickness and flexibility are shown in Tables 6-8. All resulting values are well within the acceptable range for application of coated fabrics, including automotive release liners. It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention. TABLE 4______________________________________Coating FormulationsFormulation (Grams)COMPONENT 1 2 3 4 5 6 7 8______________________________________Acrylated aromatic 80 80 80 80 80 80 80 80urethane oligomerAcrylated ester of 10 10 10 10 20 20 20 20tripropylene glycolAcrylated ester of alkyl 10 10 20 20 10 10 20 20alcoholAromatic substituted 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0propanolPolyether modified 0 0.1 0 0.1 0 0.1 0 0.1dimethyl polysiloxanecopolymer______________________________________ TABLE 5______________________________________Coated Fabric Combout.sup.1 FORMULATION.sup.2CONTROL.sup.3 1 2 3 4 5 6 7 8______________________________________38.9 129.5 148.7 196.1 170.0 156.5 185.7 123.8 166.0______________________________________ .sup.1 The combout resistance test uses an instrumental tensiometer and special test fixture to comb yarns out of the woven fabric and measure th force required to do so. The test method and apparatus are described in "The Steger Tensile Test," Bobbin Magazine, June 1985, pp. 140-141. .sup.2 Correspond to formulations in Table 4, all coatings silkscreen applied through a mesh screen; cured with ultraviolet light source at 100 feet/minute. .sup.3 Control is uncoated 420 denier nylon fabric, Highland Industries Style #39010. TABLE 6______________________________________Weight Gain by Coated Fabric (Oz./Sq. Yd.)FORMULATION1 2 3 4 5 6 7 8______________________________________0.29 0.71 1.16 0.81 1.34 0.88 0.66 1.02______________________________________ TABLE 7__________________________________________________________________________Thickness Increase by Coated Fabric (Inches)FORMULATION1 2 3 4 5 6 7 8__________________________________________________________________________0.0008 0.0004 0.0004 0.0002 0.0005 0.0002 0.0002 0.0002__________________________________________________________________________ TABLE 8______________________________________Flexibility of Coated Fabrics (In. Deflection, Warp/Fill)FORMULATION______________________________________#1 #2 #3 #4______________________________________.124/.478 .333/.501 .205/.667 .580/.663______________________________________#5 #6 #7 #8______________________________________.591/.438 .676/.756 .759/.708 .737/.796______________________________________ TABLE 9______________________________________Properties of Coated Fabric.sup.1TEST RESULTS______________________________________Coated Fabric Combout Resistance (Lbf) 166.5Weight Gain by Coated Fabric (Oz./Sq. Yd.) 0.75Thickness Increased by Coated Fabric (Inch) 0.0004Flexibility of Coated Fabric 0.233/0.301(Inch, Warp/Fill)FMVSS.302 Flammability, Warp/Fill SE/SE______________________________________ .sup.1 420 denier nylon fabric Highland Industries, Style #32012 .sup.2 Coating applied through a mesh screen; cured with ultraviolet ligh source at 50 feet/minute.

A method for reinforcing fabric edges to prevent raveling or fraying of a release liner fabric during cutting and subsequent use. The method is carried out by coating the yarn crossovers with a flexible, thin film of a radiation polymerized resin and then curing the coating system at high production speeds. The fabric is cut in those areas where the cured coating is applied, thereby providing a band or border of cured resin of sufficient width to prevent raveling of the fabric edge. The method is particularly suitable for the fabrication of release liners used for the protection of rubber sheeting for manufacturing automobile tires.

CROSS-REFERENCE TO RELATED APPLICATIONS Reference is made to the copending, commonly assigned U.S. patent application, Ser. No. 08/912,709, filed Aug. 18, 1997 entitled Integrated Pulsed Propulsion and Structural Support System for Micro-satellite, the disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION This invention relates to micro-electromechanical systems (“MEMS”) and, more particularly, to micro-miniaturization of electrical switches and arming and firing devices having application in missiles, rockets, and like apparatus. BACKGROUND In order to prevent a rocket motor, warhead, explosive separation device or energetic material, collectively sometimes referred to as target devices, from being unintentionally operated during flight or in any circumstance that could produce an extreme hazard to personnel or facilities, an “arm fire” device is customarily incorporated in the firing control circuit for the foregoing devices as a safety measure. The arm fire device electrically and mechanically interrupts the “ignition train” to the target device so as to prevent accidental operation. The arm fire device includes a mechanism that permits the target device to be armed, ready to fire, only while electrical power is being applied to the target device. When that electrical power is removed, signifying the target device is disarmed, the mechanism of the arm fire device returns to a safe position, interrupting the path of the ignition train. Another known device of similar purpose, is called the “safe and arm” device, and is a variation of the arm fire device. The mechanism of the safe and arm device enables the target device, such as the rocket motor, warhead and the like, earlier mentioned, to remain armed, even after electrical power is removed. The device may be returned to a “safe” position only by applying (or reapplying) electrical power. The safe and arm device is commonly used to initiate a system destruct in the event of a test failure, for launch vehicle separation and for rocket motor stage separation during flight. Typically, the safe and arm device uses a pyrotechnic output which may be either a subsonic pressure wave or which may be a flame front and supersonic shock wave or detonation to transfer energy to another pyrotechnic device (and serves as the trigger of the latter device). The foregoing safety devices have been proven in service. Constructed using existing technology, those safety devices are typically of the size of a person's fist, and possess a noticeable weight of several pounds. If the weight and volume of those devices can be reduced, the payload and propulsion systems can be increased in weight and/or volume to increase the range and capability of a weapon system. Given the goal of reducing weight and volume, the arm fire device and the safe and arm device are candidates for significant miniaturization in the system. As an advantage the present invention addresses the function of arm fire devices and safe and arm devices, and accomplishes the functions of the foregoing devices in an electromechanical apparatus that is significantly smaller in size and weight than the presently existing counterparts. Micro-electromechanical systems (“MEMS”) have become known to a degree. The MEMS devices reported in the literature represents an achievement milestone in miniaturization and integration of electromechanical machines and devices. That technology provides, as example, a toothed gear that is smaller in size than a speck of dust, invisible to the eye. MEMS devices are sometimes fabricated by employing the photo-lithograph mask and etch techniques familiar to those in the semiconductor fabrication technology to form micro-miniature parts of silicon, which are annealed to strengthen the part. In copending application Ser. No. 08/912,709, a micro-miniature pyrotechnic gas generator, called a micro-thruster is described that is capable of issuing a microburst of gas in which the expelled gas is applied to produce thrust for a micro-satellite or other small craft. Accordingly, a principal object of the invention is to micro-miniaturize arm fire and safe and arm devices. Another object of the invention is to provide electrical single operation switch designs for fabrication using MEMS fabrication techniques. An ancillary object of the invention is to produce micro-miniature single operate electrical switches. SUMMARY OF THE INVENTION Miniaturized light-weight arm fire and safe and arm devices are made possible by incorporating the advantages of micro-electromechanical system (“MEMS”) technology in the devices. In accordance with the invention, arm fire and safe and arm devices include an electrically operated pyrotechnic initiator or, as variously termed, MEMS ignition device to generate a pyrotechnic output upon command and an electro-mechanically movable pyrotechnic barrier that blocks propagation of the shock wave and expanding gases of the pyrotechnic output if the device is not intended to be fired. The pyrotechnic output is transferred from the device for use in igniting an explosive train, either directly or indirectly, the latter, as example, by operating an electrical switch. To prevent output through unintended operation of the MEMS ignition device the pyrotechnic barrier is normally positioned to block the output; and the barrier is moved out of the way when output is desired. In the arm fire device, the barrier automatically prevents an output when electrical power is removed from the unit. In the safe and arm device, the barrier, once moved out of the way, remains out of the way, even when electrical power is removed. As an additional feature, the switch operator of a micro-miniature electrical switch receives the pyrotechnic output and is moved in position by the pyrotechnic output to close a pair of normally open electrical contacts. The contacts may be included in an electrically operated explosive train. An ancillary invention in a miniature single operation electrical switch includes an electrically operated MEMS gas generator, a movable switch operator and a pair of electrical contacts. On applying a current pulse, a microburst of hot gas is generated that forces the switch operator to shift in position to change the condition of a DC current path through the electrical contacts. The foregoing and additional objects and advantages of the invention together with the structure characteristic thereof, which was only briefly summarized in the foregoing passages, will become more apparent to those skilled in the art upon reading the detailed description of a preferred embodiment of the invention, which follows in this specification, taken together with the illustrations thereof presented in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is an embodiment of an arm fire device as the embodiment appears in the unarmed (or safe) mode; FIG. 2 shows the embodiment of FIG. 1 as the embodiment appears in the fire mode; FIG. 3 illustrates in a partially exploded view a MEMS ignition device used in the embodiment of FIG. 1; FIG. 4 is an embodiment of a safe and arm device as the embodiment appears in the safe mode; FIG. 5 shows the embodiment of FIG. 4 as the embodiment appears in the arm mode; FIG. 6 illustrates a rotary form of the movable barrier that may be substituted for the slidable barrier component in an alternative embodiment of the arm fire device of FIG. 1; FIGS. 7 and 8 illustrate an embodiment of a single operation digital gas motivated electrical switch in respective standby and operated modes; FIG. 9 partially illustrates an alternative embodiment of a single operation digital gas motivated electrical switch; FIG. 10 partially illustrates a further alternative embodiment of a single operation digital gas motivated electrical switch; and FIGS. 11 and 12 illustrate a still further alternative embodiment of a single operation digital gas motivated electrical switch in normal and operated positions, respectively. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 to which reference is a not-to-scale pictorial view of an embodiment of an arm fire device 1 constructed in accordance with the invention illustrating the device in a top plan view and in the unarmed (safe) position. The device includes a base 3 , suitably of a conventional resin based printed circuit board, ceramic substrate or other substrate, and the various components attached to the top surface of base 3 . Those components include a MEMS ignition device 5 , electromagnet solenoid 7 , and a multi-part mechanical slider assembly 9 . That slider assembly includes a movable slider 10 , a firing piston 11 , a firing piston channel 13 and shear pin 15 . The slider 10 is oriented perpendicular to the firing piston channel 13 for transverse movement. The slider contains an upper portion that is solid and serves as a barrier, a like bottom portion 16 and a window 12 between the two cited portions, as later more fully described herein. A tension spring 14 attaches to the remote end 16 of slider 10 and the armature 6 of solenoid 7 connects to the upper end of slider 10 . Metal leads 17 and 18 , plated on the base, electrically connect the terminals of electromagnet 7 to respective edge pins on an edge of the base 3 . Likewise plated-on metal leads 19 and 20 electrically connect the terminals of the MEMS ignition device 5 to respective edge pins on the right edge of base 3 . A pair of contact pins mounted to base 3 connect via respective plated-on leads 21 and 23 to respective edge contacts on the base. The contact pins are positioned to contact a conductive metal end on slider 10 , which serves as an electrical bridging contact, when the slider is in the safe position illustrated in the figure. Through the edge contacts, the circuit through the pin contacts connect to an indicator circuit, not illustrated, so that when the slider is in the safe position the circuit through leads 21 and 23 is closed and an indicator, such as a lamp, will illuminate indicating “safe”, to the operator. As a mechanical indicator, the slider 10 may be painted with green 71 and red 73 colored patches, only one of which may be viewed through an indicator window in the cover, not illustrated, to the arm fire device. Normally the green patch is visible in the safe mode. When the unit is placed in the arm mode, later herein described, the red patch is then visible through the indicator window in lieu of the green patch. If a safe condition is not indicated for any reason, then personnel should investigate to determine the cause. Further, leads 24 and 26 are connected to leads 19 and 20 that lead to the ignition device 5 , and to respective contacts located on the side of the slider 10 . The latter contacts are in contact with another electrical bridging contact on the lower side of slider 10 , when the slider is in the unarmed mode, as illustrated in the figure. The bridging contact places a short-circuit across the electrical circuit to the MEMS ignition device 5 to prevent inadvertent electrical energization of that device as an added safeguard. Packaged similar to the packing used for semiconductor chips, preferably the unit may be plugged into a standard integrated circuit chip socket to mount and connect the device to external control and power circuitry, not illustrated. Although the foregoing components are three-dimensional in geometry, the components are of a very short height in this miniature device. Hence, a side view of the components does not offer any details of particular note and, accordingly, need not be illustrated. Firing piston channel 13 may be constructed of flat rectangular tubing that has a rectangular passage cut through the sides to provide the mounting for the slider assembly 9 . Using a microscope the firing piston 11 is inserted into the channel and a passage in a side of that piston is aligned with a hole drilled or cut into the side of the rectangular tubing of the channel 13 . The shear pin 15 is then inserted into place to hold firing piston 11 in place in the channel. Slider 10 is rectangular in cross section and sufficient in size to fill the lateral passages in the firing piston channel but with sufficient clearance on the sides to move freely through that channel. If found necessary or desirable, guide rails may be included in the slider assembly 9 to guide slider 10 as it moves, as described herein, assuring that the slider does not bind. Slider 10 may be formed of a metal or a magnetic metal material. The central section of the slider assembly contains an opening or passage 12 and another passage orthogonal thereto, not visible in the figure, that leads to the right and opens into channel 13 . The window portion is bounded by four straight frame members, only two of which are visible in this top view, joining the upper portion of the slider to the lower section 16 . The bottom surface of the slider underlying window 12 is closed by a panel, and the left vertical side of the slider adjacent window 12 is also closed by a panel, not illustrated. On assembly of the device, the slider is pushed to the position illustrated with the upper barrier portion of slider 10 blocking firing channel 13 . With the assistance of a microscope, the ends of spring 14 are hooked into holes, not illustrated, formed in the base 3 and in slider assembly 9 , or may be soldered to those components. Preferably, a fusible link 40 is mechanically coupled across spring 14 , such as by soldering, to normally restrain the spring, preventing the spring from expanding. The fusible link restrains slider 10 from changing in position at this stage, notwithstanding shock or vibration, as might occur when the arm fire device is being transported. Leads 41 A and 41 B extend the circuit from the link to contacts at the edge of base 3 . That restraint is removed at the appropriate time by applying current over those leads to break the link. The length of the upper portion of slider 10 is about equal to the distance to the front of electromagnet solenoid 7 so that when the slider is moved through the firing channel 13 to, as example, into abutment with the solenoid or the uppermost position of travel, as later herein described during operation, the right hand side window, not visible in the figure, that is perpendicular to window 12 , is centrally positioned in the firing piston channel 13 and provides a clear passage through that channel into the slider 10 , and, through a right hand turn, (upwardly from the plane of the drawing) through window 12 . The foregoing components may be fabricated to the requisite miniature size by any of the many available precision metal machine shops, particularly those firms having some experience with the MEMS technology or other miniaturized fabrication. The electromagnet 7 and firing piston channel 13 , the latter supporting slider assembly 9 , are attached to base 3 , as example, with epoxy. MEMS ignition device 5 is also mounted at the end of the channel 13 , through an end cut-out in that channel to base 3 , suitably by epoxy. MEMS ignition device 5 is preferably constructed as described in copending application Ser. No. 08/912,709, referred to earlier. In that structure a quantity of solid pyrotechnic material, such as lead styphenate or zirconium potassium perchlorate, is confined within millimeter (micro-miniature) sized cavity and the cavity is sealed by a wall. In other embodiments in which sub-sonic velocity of gas is desired, lead phtalate may be substituted. By design, that sealing wall is constructed to be weaker in strength than other walls in the cavity or contains a portion of that wall that is weakened. To complete the ignition unit, the cavity is mounted in thermal conductive relationship to an electrical resistance heater element associated therewith. The MEMS ignition device produces a pyrotechnic output, typically a subsonic pressure wave or supersonic detonation wave, occurring, typically over an extremely short time interval of less or equal to one-thousand micro-seconds. A typical MEMS ignition device in size measures about 900 μm by 900 μm×1400 μm. When one desires the unit to provide a pyrotechnic output, electric current is applied to the heater. Within a millisecond or so, the heat generated couples into the cavity and ignites the confined pyrotechnic material, which instantaneously produces expanding hot gas and a shock wave sufficient in force to break through the weaker wall of the unit. Such MEMS ignition devices can be provided in many different forms. As illustrated in FIG. 3, a suitable pyrotechnic device 5 ′ may be fabricated on a substrate 27 , such as a circuit board, ceramic layer or other conventional substrate material. A thermal resistive material 28 is deposited on the substrate, a small pot or cavity 29 , about {fraction (1/16)} th inch in diameter is attached by epoxy atop the resistive material, pyrotechnic ingredient 30 is inserted into the pot, and the weak-strength cover 31 is sealed in place closing the cavity. Electrical contacts 32 and 33 and the associated wiring on the circuit board or substrate permit electrical current to be applied to resistance heater 28 . The foregoing pyrotechnic device may be positioned in the combination of FIG. 1, as 5 , oriented so that the lid is in the channel facing the direction of firing piston 11 . Returning to FIG. 1, the operation of the device is next considered. In safe mode, which FIG. 1 illustrates, electromagnet solenoid 7 remains unenergized. The slider 10 is positioned blocking channel 13 . Firing piston 11 is held in place by shear pin 15 and the electrical triggering circuit to MEMS ignition device 5 remains short circuited by the bridging contact at the side of the slider. Should the MEMS ignition device 5 be fired inadvertently, as example, should an ill-trained technician rest a hot soldering iron on the ignition device, piston 11 will be forced forward to break shear pin 15 . However, the lateral force is not great enough to force slider 10 out of channel 13 or otherwise remove that barrier. Thus the pyrotechnic blast cannot propagate through window 12 . In the latter regard, it is noted that the side walls of the firing channel shown to the left in the figure adds further support to the side of the upper portion of slider 10 , forming, so to speak, a flying buttress to prevent further lateral movement of the firing piston 11 . The hot gas and pressure remains confined and cannot reach a “secondary ignitor”, not illustrated, external of the arm fire device of the system in which the arm fire device is installed. Everything thus remains “safe”. Once the arm fire device 1 has been transported and installed in a system, personnel apply electrical current to the fusible link 40 via leads 41 A and 41 B, and the current melts the link. That removes the restraint from spring 14 . When one desires to arm a target device, the electromagnet solenoid 7 must be energized. By applying current to electromagnet 7 over leads 17 and 18 , the device transitions into the “arm” mode. The electromagnet solenoid magnetically draws armature 6 within the coil of the solenoid, pulling slider 10 to which the armature is connected toward the solenoid against the restraint of spring 14 , which expands and is placed in tension. As the slider 10 is drawn to solenoid 7 , the barrier portion of the slider is moved out of channel 13 , removing the blockage from the channel, such as is illustrated in FIG. 2 to which reference is made. When the slider reaches the uppermost position of travel, the device is ready to “fire”. The circuit through leads 21 and 23 is broken to result in a signal for personnel. In the indicator window in the cover, not illustrated, the green colored patch on the slider moves out of view and is replaced by the red patch 73 . The device is thus in the arm mode, ready to be fired. As long as the electromagnet solenoid 7 remains energized, the device remains in the armed condition. Should the solenoid be de-energized, spring 14 pulls slider 10 back to the normal “safe” position. The shear pin 15 , another safety precaution, is strong enough to obstruct travel of the firing piston 11 when the latter is motivated only by vibration and/or acceleration, since the piston is thin, light weight, relatively flat and possesses insufficient moment of inertia. To fire the device, electrical current is next applied to the input terminals of MEMS ignition device 5 via leads 19 and 20 . The ignition device produces a “micro-burst” of hot gas and pressure that is directed against firing piston 11 . Under the force exerted by the rapidly expanding hot gas and pressure wave, the shear pin 15 breaks and the firing piston 11 is propelled through channel 13 to the left, ultimately striking the side wall, not illustrated, to window 12 in slider 10 , covering a portion of window 12 , but leaving a portion of that window unobstructed. The hot gases and pressure wave exit through window 12 , perpendicular to the plane of the paper in FIG. 2, through which the gas and pressure may be applied to initiate a larger explosive device, the secondary ignitor, either directly or indirectly. As later herein described the foregoing may be combined with an electrical switch of micro-miniature size to electrically trigger an electrically actuated explosive device, such as illustrated in FIGS. 6 through 10 later herein described. In a practical example the base 3 of the foregoing embodiment is 2.5 cm by 2.5 cm square and 0.1 cm thick; and the entire unit weights about 2 grams. Compared to the “fist” sized units currently being used, weighing approximately 32 ounces, the arm and fire device of the present invention represents an improvement in weight alone of more than 99.9%, and a volume savings of about 99.99%. A safe and arm device constructed in accordance with the invention is illustrated in FIGS. 4 and 5 to which reference is made. As recalled, in this kind of device, the device is armed by application of electrical power, and remains armed even when the electrical power is subsequently withdrawn. The device is reset to the safe mode by application of power. As generally observed from the figures, the structure of the safe and arm device employs many of the same components that are included in the arm fire device of FIG. 1 . To avoid unnecessary repetition and to facilitate understanding of the embodiment, the elements of this embodiment are given the same denomination as the corresponding element of the prior embodiment. Only those components added or the modifications to those components are given a new denomination. A second electromagnet solenoid 8 is included in the embodiment of FIG. 4, in lieu of the tension spring 14 used in FIG. 1 . Leads 72 and 74 are included on base 3 to connect current to the solenoid 8 , when the solenoid is to be operated. A pair of spring clip formed latches are mounted to the base, one on each side of the path of movement of slider 10 and at the bottom end of the slider, respectively. The upper and lower ends of slider 10 are notched on each side to form the catches for the releasable latches. The latches are designed to release their grip on the slider, when the solenoid exerts a linear pull on the slider. The latches should hold the slider against foreseeable shock and vibration. As in the prior embodiment in the “safe” condition illustrated, should MEMS ignition device 5 inadvertently fire, the hot expanding gases and the pressure wave will be sufficient to force firing piston 11 to the left and break shear pin 15 , which otherwise holds that piston stationary. However the piston strikes the side of slider 10 and cannot move any further to the left. When current is applied to electromagnet solenoid 7 (via leads 17 and 18 ), the solenoid pulls in the armature 6 , and, thereby releases latch 76 , and pulls the slider assembly close, the uppermost position of travel, as shown in FIG. 5 to which reference 25 is made. The window 12 in slider 10 is moved into place in firing channel 13 , removing the barrier from the channel. As in the prior embodiment, the device is ready to fire. When moved to electromagnet solenoid 7 , the spring clips 75 engage the notches in the side of the upper end of slider 10 to latch the slider in place. Should the power to the electromagnet solenoid 7 be removed, the latches prevent the slider from moving. Hence, the slider remains in the armed position illustrated, ready to fire. As in the prior embodiment, when the device is in safe mode, an indicator circuit is closed through leads 21 and 23 , the contacts abutting the side of piston 16 and the conductive bridging contact on the side of the piston and the green patch 71 is visible through the indicator window in the cover. The firing of the device is the same as in the prior embodiment, and need not be repeated. If one wishes to halt the arm condition of the device and return to the safe mode, then current is applied to electromagnet solenoid 8 . The electromagnet produces a magnetic field that pulls the solenoid armature 4 into the solenoid. Since armature 4 is attached to the lower end of slider 10 , the slider is pulled back to the normal position illustrated in FIG. 4 . The force produced by the solenoid is sufficient to overcome the restraining force of the latches 75 . The spring clips of the latch are forced out of the notches as the slider is pulled toward electromagnet 8 . On completion, the device is restored to the position shown in FIG. 4, and the indicator circuit and the mechanical indicator both indicate “safe”. The foregoing embodiment of FIG. 1 employed a slide type of arming device. The function served by slider assembly 9 may alternatively be served by a rotary type device, such as the device pictorially illustrated in FIG. 6 to which references is made. In this a motor mechanism 34 , containing electromagnetic coil 35 , turns the shaft of a cylindrical valve 36 by ninety degrees against the restraint of a spring when electromagnet coil 35 is energized with DC current. The side of the cylinder contains two openings 38 and 39 that are spaced ninety degrees apart about the cylindrical axis. The cylinder also contains an internal passage between those openings. In application, when the motor winding is energized the shaft turns by ninety degrees, to orient the two passages one way. When the winding is deenergized, the magnetic pull of the winding collapses, and spring 37 turns the shaft in the reverse directing reorienting the passages in cylinder 36 to the normal position. As placed into the device, as example, of FIG. 1, the orientation in the normal position normally prevents gas from passing through the cylinder when the motor winding is not energized. In such application, the side of cylinder 36 is positioned against the end wall of a passage, such as passage 13 in FIG. 1, whose end edges are for this adaptation shaped to the diameter of the cylinder so as to mate with the right and left hand cylindrical surfaces of the cylinder. Normally, when motor winding 35 is not energized, passage 39 faces into the firing channel 13 , but the connected passage 38 faces the bottom of the mounting 3 , thereby blocking the escape of any pressurized gas, should the gas generator 5 inadvertently fire. When the motor winding 35 is energized, the shaft turns by ninety degrees, orienting passage 39 upwardly, and passage 38 into passage 13 . If the MEMS ignition device 5 is fired, the pyrotechnic output travels through passage 13 as earlier described in connection with the operation of FIG. 1, then through the cylinder and out passage 39 . If the power extinguishes before firing the ignition device, the spring restores the cylinder to the blocking orientation, the “safe” position. As one appreciates in this embodiment and in all of the other embodiments, the side walls of the passages, such as passage 13 must be of a material and/or thickness and strength that is sufficient to withstand the force of the anticipated pyrotechnic output without falling apart or distorting in shape. Reference is made to FIGS. 7 and 8 which illustrate an alternative MEMS single operation electrical operated MEMS gas generator motivated electrical switch prior to and following operation. The switch includes a pair of electrical leads or conductive metal contacts 42 and 43 , elongate in geometry, positioned at the lower end of a rectangular shaped housing 44 . A pair of relatively thick interior sidewalls or supports 45 and 46 are affixed to opposite walls of the housing. Both the housing walls and the sidewalls supports 45 and 46 are formed of electrically non-conductive material, such as Silicon. Contact 42 lies on the bottom of the housing extending over a considerable portion of the bottom surface. The contact further extends through support 45 and the adjacent wall to the housing exterior so that the contact may be accessed by external circuitry. Contact 43 is held in a cantilever fashion by support wall 46 in a position overlying contact 42 and extends parallel to the latter contact. Contact 43 is sufficient in length to extend over a major portion of that portion of contact 42 that is located interior of housing 44 ; and also extends through the wall to the housing exterior. Metal contacts 42 and 43 define a normally open electrical circuit through the switch housing. Contact 43 is sufficiently rigid to maintain sufficient clearance to the adjacent contact in the presence of any foreseeable shock and vibration. A bar membrane 47 extends across the housing interior, supported by the upper ends of sidewalls 45 and 46 to which the bar is affixed. A rectangular block of non-conductive material 48 , suitably of silicon, is supported in between side walls 45 and 46 from the underside of bar membrane 47 , leaving a slight clearance on each of the right and left hand sides of the block, suitably less than one micron in clearance. Block 48 , sometimes referred to as the “silicon hammer”, overlies and is spaced from contact 43 . The upper end of housing 44 contains the MEMS gas generator 49 , pictorially illustrated, that was earlier described. Electrical power for initiating the generator 49 is supplied via electrical leads 50 a and 50 b . A small ledge 51 , only portions of which are illustrated, extends about the upper walls of housing 44 and serves to support a covering membrane 52 , that divides the internal region above, containing gas generator 49 , from that below. Together with bar membrane 47 , covering membrane 52 defines a plenum for gas. Both membranes 47 and 52 are rupturable. When the switch is to be operated, a short pulse of current is applied via leads 50 a and 50 b to the MEMS gas generator, which, in response, explodes the confined pyrotechnic material, producing a burst of hot expanding gas. The force produced by the gas is released against membrane 51 , which ruptures, and further expands into the plenum region, applying the force of the gas against the membrane bar 47 . The membrane bar and the silicon hammer 48 are driven down by the force, rupturing membrane bar 47 and driving silicon hammer 48 into contact 43 . As illustrated in FIG. 8, silicon hammer presses against contact 43 and being fragile the contact deforms and/or bends and presses against contact 42 , closing an electrical circuit through the switch. In a practical example, in overall dimension the switch of FIG. 7 may be one millimeter square, membrane 52 may be one mm in thickness and be of any appropriate material, such as a metal foil. Membrane bar 47 man be about one-half micron in thickness and comprise a more thick metal foil. Side walls 45 and 46 may be about 100 microns thick and be formed of silicon. The housing may comprise any insulator material. Using conventional techniques the cantilever contact 43 is formed of silicon. An electrode, a conductive load pad is manufactured and positioned under the cantilever contact. When the switch is fired, the pressure of the pyrotechnic blast breaks the plenums and drives the hammer. In turn the hammer impacts the cantilever contact, forcing the cantilever into contact with the electrode 42 , thereby closing the switch. Electrical switches may be of a mechanical design different from that of FIGS. 7 and 8, all of which make use of the MEMS digital propulsion gas generator to operate the switch. Several of those alternative designs are illustrated in FIGS. 9, 10 , 11 and 12 . The switch of FIG. 9 includes the pair of relatively thick side walls 54 and 55 , as in the preceding embodiment, a pair of electrical contacts 56 and 57 , and a movable block 58 , the hammer. In this embodiment hammer 58 is of electrically conductive material or has electrically conductive sides so that the hammer may also serve as a bridging contact between contacts 56 and 57 . The switch contains the same upper section, not illustrated, as in the switch of FIG. 7 . When the MEMS device operates and creates the force to rupture the membranes and drive the hammer 58 down, the side of the hammer brushes against wiper contact 57 and the front moves into contact with contact 56 , such as illustrated in the operated mode, in the figure. The electrical circuit completes through the conductive sides of the hammer 58 . In this embodiment, as an improvement, the face of the hammer includes a projection in the shape of a truncated right cone, and the contact 56 includes a conical shaped passage that is aligned with the cone. The conical passage provides a mechanical device that allows for slight misalignment between the conductive cone of the hammer and the axis of the passage, providing for self-alignment. Additionally since the cone may scrape against the conical walls when the hammer 58 is descending and essentially clean the contact of any dirt resulting in a more reliable electrical contact as compared to a contact that simply is pressed against the contact surface. In the switch embodiment partially illustrated in FIG. 10, an electrically conductive metal diaphragm, 62 resembling a coffee can or oil can lid is used to provide a bridging contact for the spaced contacts 63 and 64 . A second metal diaphragm 61 is mounted in overlying relationship, leaving a gas chamber there between. Both diaphragms are attached about the peripheral edge to the walls 59 and 60 , at respective vertical locations along the wall. In the switch, contacts 63 are mounted through passages in insulating walls 59 and 60 with ends of the two contacts facing one another across an air gap. The membrane 62 normally bulges in one direction, the upward direction, as example. When a force applied to that membrane in the opposite direction attains a sufficient level, the membrane inverts, and bulges in the opposite direction. In the switch, force is applied by the expanding gas released by the MEMS thruster, not illustrated, against diaphragm 61 and forces the diaphragm downward, compressing the gas in the confined region. In turn that compressed gas creates a force on diaphragm 62 , which rises to a sufficient level to invert diaphragm 62 . By design, the downward bulge is great enough to permit the metal diaphragm to contact both contacts 63 and 64 bridging a circuit between the contacts. Another micro-miniature switch structure is partially illustrated in FIGS. 11 and 12 in normal and operated positions, respectively. As with the prior switch embodiments the MEMS gas generator is omitted from the illustration. In this embodiment the switch operator is a plunger 67 . Electrical terminals 68 and 69 serve as the switch contacts. Each electrical terminal is an elongate strip of conductive metal, attached to housing 70 . Each strip extends from the exterior of the housing, through the housing wall and through a portion of the housing interior with electric terminal strip 69 overlying and parallel to a portion of electric terminal strip 68 disposed on the bottom of the housing. Housing 70 includes two side walls and a top wall 71 , the latter containing a passage for the shaft of plunger 67 . The plunger includes a wide diameter head, greater in diameter than the shaft; and the head is located within the upper housing region that receives the micro-blast of gas from the micro-thruster, not illustrated. The plunger may be formed of a light weight rigid metal or plastic material. On assembly, the shaft of plunger 67 is inserted through the passage and the end of the shaft abuts the upper surface of contact 69 . The rigidity of the contact strip 69 should be sufficient to permit the contact to bear the weight of the plunger without significant deflection, maintaining clearance with the other contact strip 68 . The shaft of the plunger is of sufficient length to permit the head of the plunger to be slightly elevated above the upper surface of wall 71 when the end of the shaft is supported on contact strip 69 . This is the normal position of plunger 67 . When the switch is operated, the plunger is moved down to the second position with the head abutting the upper surface of wall 71 , as later herein described in connection with FIG. 12 . As in the switches earlier described, when the switch is to be operated to close a DC circuit between contacts 68 and 69 , a pulse of current is applied to the input of the micro-thruster, not illustrated, of the switch. The current pulse heats the resistance material of the igniter, and ignites the pyrotechnic material in the housing of the micro-thruster, in the manner earlier herein described. The micro-thruster produces a micro-blast of hot expanding gas accompanied by a spiked rise in pressure. That gas and pressure impulse is directed into the chamber above wall 71 , and, hence, against the head of plunger 67 . As shown in FIG. 12, the plunger is thereby driven downward until the head abuts the wall 71 . In moving down, the shaft of the plunger presses against and bends the cantilevered end of contact 69 into contact with contact 68 , which completes a DC circuit through the switch. Contact 69 may be constructed to be deformable in character, in which event the switch remains closed even after termination of the micro-blast. The contact may alternatively be flexible in character, such as spring copper alloy, so as to restore to the first position when the micro-blast extinguishes. It is appreciated that the foregoing electric switch structures are of the normally open variety. That is, the switch contacts are normally separated to interrupt a DC current path through the contacts of the switch, and, when the switch is operated, the contacts are in abutment closing a DC current path there through. The foregoing mode of switch operation is consistent with present requirements for electrically detonated explosive devices that require the application of a current to ignite the device. However, in alternative embodiments some designers may chose to require the interruption or opening of a normally closed DC circuit to signify the onset of an electrically initiated explosive train. In that case the foregoing switch structures of FIGS. 7-12 should be modified so that the switch contacts are normally in electrical contact, and separate to break the DC circuit with the switch is operated. It is believed that the foregoing description of the preferred embodiments of the invention is sufficient in detail to enable one skilled in the art to make and use the invention. However, it is expressly understood that the detail of the elements presented for the foregoing purpose is not intended to limit the scope of the invention, in as much as equivalents to those elements and other modifications thereof, all of which come within the scope of the invention, will become apparent to those skilled in the art upon reading this specification. Thus, the invention is to be broadly construed within the full scope of the appended claims.

Miniature arm fire and safe and arm devices include an electrically operated pyrotechnic initiation device ( 5 ) to generate a detonation wave upon command and a movable pressure barrier ( 9 ) that blocks propagation of the detonation wave if the device is not intended to be fired and opens a window ( 12 ) to transfer the detonation wave externally of the device. The detonation wave may in alternate embodiments be a subsonic flame front and pressure wave or a supersonic shock wave, respectively. An electromagnet ( 7 ) may serve to move the pressure barrier. Detonation waves output from the device have application in igniting an explosive train, either directly or indirectly, the latter by operating an electrical switch. In the arm fire device, the barrier automatically prevents a detonation output when electrical power is removed from the device. In the safe and arm device, the barrier, once moved out of the way, remains out of the way, even when electrical power is removed. Various forms of miniature single operate electrical switches are described that may be operated by the foregoing devices.

BACKGROUND OF THE INVENTION The present invention relates to a method of producing the latch bearing in a latch needle for textile machines, and more particularly to such a latch needle which includes a shank having a longitudinally extending latch slot laterally delimited by needle shank cheeks, and a latch having a bearing member or portion at an end thereof inserted into the latch slot and positioned correctly therein with the use of an elongate hinge pin which is laterally inserted into laterally extending bores in at least one of the needle shank cheeks and into the bearing portion of the latch and is securely fixed in the bores in said needle shank cheeks. The invention also relates to an apparatus for implementing this method. A prior apparatus of this kind (German Offenlegungsschriften Nos. 3,546,037 and 3,606,962) includes a clamping device for a latch needle into whose longitudinal latch slot the latch has been pre-assembled. A hole punching device o one side of the clamping device is equipped with a punch able to penetrate through the needle shank cheeks which laterally delimit the latch slot and through the bearing portion of the latch. A coaxial counter punch which is longitudinally displaceably mounted in bearing means on a side of the clamping device opposite the punch cooperates with the punch and is advanceable toward the clamping device. The term "textile machines" is here to be understood to mean stitch forming machines, particularly knitting machines, but also specialized sewing machines and the like, in which yarn, wire and similar thread-shaped material is processed. The term "latch needle" includes all yarn etc. processing tools in which a latch or similar latch-like element is pivotally mounted in the latch slot of a shank. In the latch needles primarily employed in practice at present, the bearing portion of the latch is generally configured so that the bearing hole disposed in the latch slot of the needle shank is mounted so as to pivot on two pivot or hinge pins pressed out of the material of the needle shank cheeks (see U.S. Pat. No. 3,934,109 and British Patent No. 836,297). The manufacturing process for this type of latch bearing is relatively simple because the configuration of the pivot pins and the installation of the latch on the pivot pins takes place practically in one process step which requires only simple and sturdy tools. Therefore, this method is quite economical, with high production rates being attainable. However, due to the unpredictable flow behavior of the material of the needle shank cheeks which is pressed into the bearing hole of the latch during the formation of the pivot pins, the pivot pins produced in this stamping process and shaped to extend from the needle shank cheeks are more or less irregularly shaped in the region of their outer peripheral faces so that the percentage of load-bearing area of the inner walls of the bearing hole for the latch on the pivot pins is relatively small. Particularly when used in fast running high performance machines, the small percentage of load-bearing area and high dynamic stresses result in a high specific load per surface area which, in turn, is the cause of premature wear phenomena. It is known that a significantly more accurate and more wear resistant bearing for the latch can be realized in that the latch is mounted on a continuous hinge pin which has a smooth, cylindrical outer peripheral surface (see German Pat. No. 3,600,621 or the corresponding U.S. Pat. No 4,723,425). However, latch needles equipped with such a hinge pin latch bearing have not found wide acceptance in the past because manufacture and assembly of such smooth, continuous hinge pins is extremely difficult in an industrial setup due to the extremely small size of these pins. To give an idea of the order of magnitude involved, the bearing hole diameter of the latch of finer needle sizes lies at about 0.28 mm while the length of the hinge pin is about 0.35 mm. In a prior art method for the production of latch bearings in knitting machine needles (see German Offenlegungsschriften DE-OS 3,546,037 and DE-OS 3,606,962), the needle shank is provided, before or after making the longitudinal slot, for example, with a transverse bore extending only through one shank cheek. A hinge pin whose length corresponds to approximately 2/3 of the needle shank thickness is pressed into the bore and then extends through the latch hole to the abutment at the opposite shank cheek which is not provided with a bore. A subsequently applied impression which surrounds the bore in the form of a ring or a corresponding annular weld serves to securely fix the hinge pin in the bore. In this case, the hinge pin is punched out by means of a punch through a die which is aligned with the bore in the needle shank and with the latch hole on the side of the needle shank. The hinge pin is punched out of a flat wire moved past the said die and is pressed by the punch into the hole in the shank cheek. Aside from the fact that the cutting edge of the die is worn out after a short period of operation and must be reground, and the cutting edge diameter is unduly enlarged by the clearance angle present at the die, the punched out hinge pins do not have continuously smooth cylindrical outer peripheral surfaces. Moreover, the method can only be used up to a ratio of the length to the diameter of the hinge pin that is 1 or less. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a way which makes it possible to economically produce a highly precise, wear resistant latch bearing for a latch needle employing a one-piece hinge pin suitable for mass production, with the hinge pin having a smooth, cylindrical outer peripheral surface and being inserted into the needle shank in a precisely predetermined length and with a precisely predetermined diameter. To solve this problem, a cylindrical wire made of a material suitable for hinge pins is provided with transversely extending notches at intervals corresponding to the length of the hinge pin. The thus notched wire is then converted by hot or cold treatment to a brittle state and then the individual hinge pins are broken off at the notches which form desired break locations. In a preferred embodiment, the procedure may be such that the wire is made of a hardenable metal which is hardened after the notches are cut and is then tempered in such a manner that the thus refined hard wire can be broken off in a smooth break. The notched wire which has been made brittle can be easily and smoothly broken off at the notches, with the position of the smooth break surface, which corresponds to the surface structure of the break, being precisely determined by the notches. Since the hinge pin, when it is broken off from the hard wire, neither changes in its shape nor in its dimensions, it can effortlessly and at high speed be inserted into the intended position in the needle and is then securely arrested or fixed there by suitable means. Since the hinge pin is hard, it does not tend to grab when it is pressed into the associated bore. Small drilling inaccuracies are compensated and equalized automatically when the smooth and hard pin is pressed in. The thus produced latch bearing therefore includes a hinge pin whose diameter and length stay within very close tolerances, with the surface of the hinge pin being manufactured with any desired fine consistency by corresponding selection or processing of the starting wire material. It is advisable for the wire to be provided with circumferential, groove-like notches which advantageously have an essentially V-shaped cross-sectional configuration. In this way a chamfer is provided at the ends of the broken-off hinge pins to facilitate insertion into the respective bore of the needle shank cheek. The notches may be cut or recessed into the wire, for example, by means of a suitable recessing head. However, embodiments are also possible in which the notches are pressed or stamped into the wire. For installation of the thus produced hinge pins, the procedure may be such that each hinge pin is initially broken off from the hard wire and is then inserted into the associated bores. Alternatively, one end of the hard wire can be initially pushed into the associated bores and to then be broken off from the hinge pin that remains in the bores. Particularly in continuous processes, it is advisable for the wire coming from a wire supply to be continuously provided with notches and to then be wound, after which the notched, coiled wire is converted to the brittle state and thereafter unwound as required to permit breaking off of the hinge pins. Such a coil of notched wire may contain, for example, 200,000 and more hinge pins which all have exactly the same characteristics. The bores in the needle shank cheeks may be produced in any desired manner. However, it has been found to be very expedient for the bores in the needle shank cheeks to be made while the pre-assembled latch needle is firmly clamped, immediately following which the hinge pin is inserted into the bores without any change in the condition of clamping. For this purpose, the bores may be punched out, for example, by means of a through hole punch. The wire material is selected for the intended purpose. The wire material is generally steel but other materials, for example, brass, bronze or plastics, etc., are also possible. To realize specific slide effects or a reduction in wear, the wire may be coated, at least in sections, with another material before the hinge pins are broken off. The coating will here generally be applied continuously, i.e. in a flow-through process, before the notches are made, but it is also possible, in principle, to apply the coating after conversion to the brittle state. Another surface treatment for the wire, for example grinding, is also possible. The inserted hinge pin can be arrested or fixed in the needle shank cheek in a known manner by laser welding, bead-like impressions, etc. In this connection, it is often of advantage for the inserted hinge pin to be fixed to the corresponding needle shank cheek only on one side to thus ensure a certain transverse elasticity of the needle shank cheeks in the region of the latch bearing. This transverse elasticity is utilized to friction brake and catch the latch when it is thrown into its rearward position. An apparatus suitable for implementing the described method and including the above-mentioned features is characterized, according to the present invention, in that, between a bearing means for the counter punch and a die of a clamping means, a transfer element is provided which is movable between a receiving position and an insertion position and is provided with receiving means which accommodate at least one hinge pin to hold it in a precisely axially parallel alignment with the hole punch axis, with charging means being associated with the transfer element so as to insert one hinge pin into the receiving means when the transfer element is in the receiving position. When the transfer element is in the insertion position, the hinge pin held in its receiving means then has its axis aligned with the hole punch axis so that the pin ca easily be inserted into the bore of the adjacent needle shank cheek with the counter punch. Particularly simple structural conditions result if the transfer element includes a flat pusher, that is, a member of substantially rectangular cross section which slides transversely along a surface of the die. In this case, the pusher is advantageously provided with a continuous bore which extends is parallel to the hole punch axis, serving as the receiving means, with a hinge pin being held in such a bore in sliding seat. A continuous process can be realized with a simple apparatus in which the charging means includes a transporting device which advances the notched hard wire in steps and with which one end of the wire can be inserted into the receiving means of the particular transfer element that is presently in the receiving position. The transfer element is associated with a breaking means which produce a bending movement between the wire and the end portion thereof which is held in the receiving means. These breaking means may include a pivotally mounted abutment which guides the notched hard wire between the transporting device and the transfer element. BRIEF DESCRIPTION OF THE DRAWINGS These and other features and advantages of the invention will be more completely understood from the following detailed description of a preferred embodiment with reference to the accompanying drawings in which: FIG. 1 is a schematic representation in a side view, partially in section, of a device according to the invention for notching a wire intended for the production of hinge pins; FIG. 2 is a sectional view to an enlarge scale of the wire notched with the apparatus according to FIG. 1, illustrating one notch; FIGS. 3 to 6 are partially schematic side cross-sectional view of an apparatus according to the invention for the production of the latch bearing of a latch needle, showing four different successive operational stages; FIG. 7 is a sectional view to an enlarged scale of the latch needle of FIG. 8 seen along line VII--VII of FIG. 8, with the latch pivoted up and showing the latch bearing produced according to the present invention; and FIG. 8 is a side view of the stitch forming portion of a latch needle equipped with a latch bearing produced according to the invention; and FIG. 9 is a side view, partially in cross section, of the latch needle portion shown in FIG. 8. DESCRIPTION OF THE PREFERRED EMBODIMENT The latch needle shown in FIGS. 7, 8 and 9 includes a needle shank 1 which may possibly be equipped with an integrally punched out needle butt followed at one end by a needle hook 2. In the region of the needle cheek 3, a longitudinally extending latch slot 4 is formed in the needle shank 1 and is provided, in the customary manner, with a passage to the underside of the needle shank. Latch slot 4 is delimited on either side by a respective needle shank cheek 5; in it, a needle latch 6 is pivotally mounted with its bearing member or bearing portion 7 lying within the latch slot 4. The latch bearing comprises a smooth-walled, cylindrical hinge pin 8 which is inserted into corresponding cylindrical, transversely extending, aligned holes or bores 9 of needle shank cheeks 5. Latch 6 is mounted so as to pivot on this hinge pin 8 with little bearing play by means of a transversely extending bearing bore 10 formed in its bearing member 7. Preferably, hinge pin 8 is arrested or fixed in one of the two bores 9 so as to be held in an axially inescapable way. For this purpose, one of its ends is welded at 11 to the associated needle shank cheek 5, for example by means of a laser beam, while its other end is merely supported in the associated bore 9 of the other needle shank cheek 5 in such a manner that needle shank cheeks 5 retain their elastic transverse mobility. However, it is also conceivable to arrest or fix the hinge pin 8 in bores 9 so that they are axially secured. The production of this latch bearing will now be described with reference to FIGS. 1 to 6. In FIG. 1, a cylindrical metal wire, particularly a steel wire, is shown wound onto a reel 12. This wire has a smooth surface and its diameter corresponds precisely to the desired diameter of hinge pin 8. This wire 13 is unwound in stages from the correspondingly driven reel 12; it initially moves through aligning rolls 14 where it is set to be precisely straight. The aligned wire 1 3 is transported through the guide channel 15 of a stationary guide member 16 of a notching device 17. Guide member 16 carries a cutting head 18 which is coaxial with the axis of channel 15. The interior of cutting head 18 is equipped with a milling tool 19 having such a profile that it cuts circumferential notches 20 (FIG. 2) of an essentially V-shaped cross-sectional configuration into the stopped wire 13. A likewise driven second reel 21 winds up the notched wire 13. The two reels 12, 21 are driven stepwise by associated stepping drives 22, 23 so that milling tool 19 cuts successive notches 20 into the wire at intervals corresponding to the length of the hinge pins. Instead of circumferential notches 20, any other type of oppositely disposed notches could be produced in notching device 17 at intervals corresponding to the length of the hinge pins, for example, oppositely disposed notches, and it would also be possible not to cut or punch the notches in a milling process but to stamp or press them in. If necessary, wire 13 may be coated with another material before or after the cutting of notches 20 in a continuous process taking place in a coating station indicated at 24, to thus produce special sliding effects or an additional reduction of wear in the latch bearing. The wire 13 wound on reel 21 which has about 200,000 or more notches 20 in it is then treated as by heating and/or cooling processes in such a manner that it takes on a brittle, hard state. In this state, wire 13 can be unwound without difficulty from reel 21, but simply bending the wire at notches 20, which act as desired break locations, easily divides the wire into individual hinge pins 8. This breaking off produces smooth break surfaces which start at the bottom of the respective V-shaped notches 20 and extend at a right angle to the axis of the wire. At the same time, the breaking process causes the frustoconical side walls 25 of each notch 20 to produce a chamfer at the frontal face of the presently cut hinge pin 8, with the shape of this chamfer being given by milling tool 19 and not being changed by the treating and breaking processes. The thus notched and hardened wire 13 is fed to the device shown in FIGS. 3 to 6. This device includes a support 26 of accurate dimensions and a counter support or female piece 27 following the support on one side. Together with a clamping jaw 28 mounted so as to be moved toward and away from counter support 27, the latter forms clamping means for a partially pre-assembled latch needle whose needle shank 1 is clamped between counter support 27 and clamping jaw 28 in the region of the needle shank cheeks 5 resting on support 26 in a manner shown in FIGS. 3 to 6. In a previous assembly step, latch 6 is inserted into longitudinal latch slot 4 and is stationarily positioned therein in such a manner that its bearing hole 10 has a precisely predetermined spatial orientation. In clamping jaw 28, which simultaneously serves as a punch guide, a guide bore 29 is formed in which a cylindrical punch 30 is mounted so as to be slideably moved back and forth and whose axis is coincident with the axis of a bore 31 of counter support 27. The pivotal axis of latch 6 of the pre-assembled latch needle is also aligned with the axis of punch 30. Spaced opposite counter support 27, a bearing means in the form of guide block 32 is disposed which includes a cylindrical guide bore 33 serving as a slide bearing that is axially aligned with bore 31 in counter support 27 and in which a impression or counter punch 34 is longitudinally movably guided. Thus, counter punch 34 is aligned with bore 31 in counter support 27. In the space between counter support 27 and guide block 32, a transfer element in the form of a pusher 35 is guided to be displaceable between a receiving position shown in FIG. 3 and an insertion position shown in FIG. 6. Pusher 35 is rectangular in cross section and lies against the side face of counter support 27. Pusher 35 is provided with a cylindrical through bore 36 which serves as a receiving means and into which a hinge pin 8 can be inserted in a sliding fit. The thickness of pusher 35 is somewhat greater than the length of a hinge pin 8. Below guide block 32 following and next to pusher 35, there is disposed a guide and abutment element 37 which is equipped with a cylindrical through bore 38 and is mounted so as to be pivotable slightly downwardly, as shown in FIG. 4 by arrow 40. A transporting device 42 driven in steps and provided with transporting rollers 41 is provided at guide and abutment element 37 to permit the advancement of a notched hard wire 13 inserted into guide bore 38, in steps of one length of a hinge pin, to the right with respect to FIG. 3. The device described above operates as follows: Once a latch needle having a pre-punched latch 6 has been clamped in the above-described manner between the counter support 27 and the clamping jaw 28 with hole punch 30 in the retracted position, the assembly of the hinge pins can begin. Transporting device 42 pushes the end of the notched and tempered wire 13 corresponding to one hinge pin 8 and coming from reel 21 into bore 36 of pusher 35 which is in its receiving position. Guide and abutment block 37 then takes on its upper position in which its guide bore 38 is aligned with the bore 36 of pusher 35 as shown in FIG. 3. Now, punch 30 is moved to the left with reference to FIG. 3, thus cutting a straight bore 9 out of the two needle shank cheeks. The two cut pieces 42 drop into the space between counter support 27 and guide block 32 and are blown away by means of a jet of air supplied through a nozzle 43. At the same time, guide and abutment element 37 is pivoted slightly downwardly, thus smoothly breaking off, at the associated notch 20, the end of wire 13 held in bore 36 of pusher 35 and corresponding to the length of one hinge pin 8 as shown in FIG. 4. Now, starting from its receiving position of FIG. 4, pusher 35 is moved upwardly into its insertion position in which bore 36 containing the broken-off hinge pin 8 is aligned with bore 31 of counter support 27. At the same time, guide and abutment element 37 has returned to its starting position shown in FIG. 3. Punch 30 has been retracted to such an extent that its frontal face is approximately flush with the facing side wall of counter support 27, as shown in FIG. 5. With pusher 35 arrested or fixed in its insertion position, impression or counter punch 34 is now advanced to the right with reference to FIG. 6, which thus pushes hinge pin 8 out of bore 36 of pusher 35 into bore 31 of counter support 27 and thus into bores 9 previously produced by punch 30 in needle shank cheeks 5. During this step of pressing in hinge pin 8, hole punch 30 constitutes the counter punch which accurately determines the insertion depth of hinge pin 8, as shown in FIG. 6. In the next following process step, impression and counter punch 34 is again retracted to its starting position shown in FIG. 3 while clamping jaw 28 is moved to the right with reference to FIG. 6 so that the assembled latch needle can be removed and replaced by a new, partially pre-assembled latch needle. Moreover, pusher 35 has now been lowered again to its transfer position shown in FIG. 3 in which its bore 36 is aligned with guide bore 38 of guide and abutment element 37. As soon as pusher 35 has reached this position, the transporting device 42 again pushes wire 13 to the right with reference to FIG. 3, by an amount corresponding to the length of one hinge pin 8, thus again reaching the starting state shown in FIG. 3. The assembled latch needle taken from the device is now subjected to further processing. For this purpose, at least one frontal face of the inserted hinge pin 8 is initially ring welded to the associated needle shank cheek 5 in a device not shown here, or is otherwise secured; then the latch needle is hardened, polished, etc. i.e. brought to its final marketable state. The described device is distinguished by very simple manipulation of hinge pins 8 because the latter are supplied contiguously, separated only by notches 20, in the form of a wire on a reel. Alternatively, embodiments are possible in which the individual hinge pins 8 are broken from the notched and hardened wire in a separate process step and are then taken over by a transfer element and brought into the effective range of impression or counter punch 34. In the described embodiment of the method, the notched metal wire 13 formed for example of steel, is converted by heat treatment and subsequent tempering, or similar treatment, to a brittle state. However, it is also possible, in principle, to cool wire formed of a material, such as brass, bronze, plastics etc., to such a low temperature that it is converted to such a state. This cooling may be effected, for example, with liquid air or liquid nitrogen. In this way, it can be accomplished that the material of the hinge pins 8 inserted into the bores 9 of needle shank cheeks 5, when reheated to ambient temperature, retains its original characteristics. Additionally, the enlargement in diameter occurring during heating can also be utilized to arrest or fix hinge pin 8 in needle shank cheeks 5. The present disclosure relates to the subject matter disclosed in Federal Republic of Germany Patent application No. P 38 00 802.5-14 filed Jan. 14th, 1988, the entire specification of which is incorporated herein by reference. It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

A method for producing the latch bearing in a latch needle for textile machines of the type in which a latch is pivotably mounted in a longitudinal slot between two cheeks of a needle shank by a hinge pin passing through mutually aligned transversely extending bores in at least one of the cheeks and a bearing portion of the latch between the cheeks. In accordance with the method a cylindrical wire is provided with transversely extending notches at intervals corresponding to the length of a hinge pin. The notched wire is converted by hot or cold treatment into a bittle, hard state. Individual hinge pins are broken off from the wire at the notches, and are subsequently inserted into the bores in the cheeks and the bearing portion of the latch to be securely fixed there.

RELATED APPLICATION DATA This application is a Continuation of application Ser. No. 10/076,990 filed Feb. 15, 2002 abandoned, which is a Continuation of Ser. No. 09/781,501 filed Feb. 12, 2001 abandoned, which is a Divisional of Ser. No. 09/047,479 filed Mar. 25, 1998, now U.S. Pat. No. 6,229,295, issued May 8, 2001, which is a Continuation of Ser. No. 08/478,605 filed Jun. 7, 1995, now U.S. Pat. No. 5,903,145, issued May 11, 1999, which is a Continuation of Ser. No. 08/384,398, filed Feb. 3, 1995, now U.S. Pat. No. 5,457,621, issued Oct. 10, 1995, which is a Continuation of Ser. No. 08/259,116 filed Jun. 10, 1994 (now abandoned), which is a Continuation of Ser. No. 07/839,967 filed Feb. 21, 1992 (now abandoned). FIELD OF INVENTION The present invention relates generally to the field of electric utility meters. More particularly, the present invention relates to electronic utility watthour meters or meters utilized to meter real and reactive energy in both the forward and reverse directions. BACKGROUND OF THE INVENTION Electric utility companies and power consuming industries have in the past employed a variety of approaches to metering electrical energy. Typically, a metering system monitors power lines through isolation and scaling components to derive polyphase input representations of voltage and current. These basic inputs are then selectively treated to determine the particular type of electrical energy being metered. Because electrical uses can vary significantly, electric utility companies have requirements for meters configured to analyze several different nominal primary voltages. The most common of these voltages are 120, 208, 240, 277 and 480 volts RMS. Presently, available meters have a different style for each of these applications, both electro-mechanical and electronic. This forces the electric utility companies to inventory, test and maintain many different styles of meters. Consequently, a need exists for reducing the number of meter types a utility need inventory by providing a meter capable of operation over a wide dynamic range. The problem of wide amperage dynamic range was addressed in U.S. Pat. No. 3,976,941—Milkovic. It was there recognized that solid state electronic meters were becoming more desirable in metering applications, however, such solid state meters had a critical drawback in their amperage dynamic range. An effort was described to improve the amperage dynamic range of solid state meters so that such meters would be operationally equivalent to prior electromechanical meters. The problem with such meters, however, was their failure to address the multiple voltage situation. Utility companies utilizing such meters would still be forced to inventory, test and maintain many different styles of meters in order to service the various voltages provided to customers. It has been recognized in various meter proposals that the use of a microprocessor would make metering operations more accurate. It will be understood, however, that the use of a microprocessor requires the provision of one or more supply voltages. Power supplies capable of generating a direct current voltage from the line voltage have been used for this purpose. Since electric utility companies have requirements for various nominal primary voltages, it has been necessary to provide power supplies having individualized components in order to generate the microprocessor supply voltages from the nominal primary voltage. Consequently, a need exists for a single meter which is capable of metering electrical energy associated with nominal primary voltages in the range from 96 to 528 volts RMS. Applicants resolve the above problems through the use of a switching power supply and voltage dividers. It will be recognized that switching power supplies are known. However, the use of such a power supply in an electrical energy meter is new. Moreover, the manner of the present invention, the particular power supply construction and its use in an electrical energy meter is novel. It will also be noted, in order to solve the inventory problem, designing a wide voltage range meter in the past involved the use of voltage transformers to sense line voltage. A significant problem associated with the use of such transformers was the change in phase shift and the introduction of non-linearities that would occur over a wide voltage range. It was not easy to remove such a widely changing phase shift or to compensate for the non-linearities. Consequently, a need still exists for a single meter which is capable of metering electrical energy associated with nominal primary voltages that also minimizes phase shift in the voltage sensors over a wide voltage range. SUMMARY OF THE INVENTION The present invention is directed to a power supply for an apparatus for metering at least one type of electrical power over a predetermined range of service voltages supplied by electrical service providers, where the apparatus comprises a voltage input circuit connected to receive a voltage component, and a processing unit. The power supply comprises a surge protection circuit which receives an input voltage, a rectifier circuit which receives an alternating current voltage from the surge protection circuit and outputs a rectified direct current voltage, a transformer which receives the rectified direct current voltage at a first winding so that current flows through the first winding, and a second winding defines an unregulated output voltage of the power supply, a switching device for permitting and preventing the flow of current through the first winding in response to a control signal, and a controller for generating the control signal based on the voltage across the third winding. The control signal output by the controller operates to disable the switching member. According to another feature of the present invention, the output of the power supply is input to a linear regulator, which outputs a regulated voltage. The regulated voltage is less than the output voltage, and the regulated voltage is output to a precision voltage reference generator. The unregulated voltage is input to the apparatus to determine the presence of a power fail condition. According to yet another feature, the power supply comprises a non-volatile supply; and the regulated voltage is input to the non-volatile supply, such that the apparatus is switched to the non-volatile supply when the regulated voltage is not present. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood, and its numerous objects and advantages will become apparent to those skilled in the art by reference to the following detailed description of the invention when taken in conjunction with the following drawings, in which: FIG. 1 is a block diagram of an electronic meter constructed in accordance with the present invention; FIG. 2 is a schematic diagram of the resistive dividers shown in FIG. 1 ; FIG. 3 is a schematic diagram of the linear power supply shown in FIG. 1 ; FIG. 4 is a block diagram of the power supply shown in FIG. 1 ; FIG. 5 is a schematic diagram of the control and switching members shown in FIG. 4 ; FIG. 6 is a schematic diagram of the startup/feedback shown in FIG. 4 ; and FIG. 7 is a schematic diagram of the voltage clamp shown in FIG. 4 . DETAILED DESCRIPTION A new and novel meter for metering electrical energy is shown in FIG. 1 and generally designated 10 . It is noted at the outset that this meter is constructed so that the future implementation of higher level metering functions can be supported. Meter 10 is shown to include three resistive voltage divider networks 12 A, 12 B, 12 C: a first processor—an ADC/DSP (analog-to-digital converter/digital signal processor) chip 14 ; a second processor—a microcontroller 16 which in the preferred embodiment is a Mitsubishi Model 50428 microcontroller: three current sensors 18 A, 18 B, 18 C; a 12V switching power supply 20 that is capable of receiving inputs in the range of 96-528V: a 5V linear power supply 22 ; a non-volatile power supply 24 that switches to a battery 26 when 5V supply 22 is inoperative; a 2.5V precision voltage reference 28 ; a liquid crystal display (LCD) 30 ; a 32.768 kHz oscillator 32 ; a 6.2208 MHz oscillator 34 that provides timing signals to chip 14 and whose signal is divided by 1.5 to provide a 4.1472 MHz clock signal to microcontroller 16 ; a 2 kByte EEPROM 35 : a serial communications line 36 ; an option connector 38 : and an optical communications port 40 that may be used to read the meter. The inter-relationship and specific details of each of these components is set out more fully below. It will be appreciated that electrical energy has both voltage and current characteristics. In relation to meter 10 voltage-signals are provided to resistive dividers 12 A- 12 C and current signals are induced in a current transformer (CT) and shunted. The output of CT/shunt combinations 18 A- 18 C is used to determine electrical energy. First processor 14 is connected to receive the voltage and current signals provided by dividers 12 A- 12 C and shunts 18 A- 18 C. As will be explained in greater detail below, processor 14 converts the voltage and current signals to voltage and current digital signals, determines electrical energy from the voltage and current digital signals and generates an energy signal representative of the electrical energy determination. Processor 14 will always generate a watthour delivered (Whr Del) and, watthour received (Whr Rec), depending on the type of energy being metered, will generate either a volt amp reactive hour delivered (Varhr Del)/a volt amp reactive hour received (Varhr Rec) signal or volt amp hour delivered (Vahr Del)/volt amp hour received (Vahr Rec) signal. In the preferred embodiment, each transition on conductors 42 - 48 (each logic transition) is representative of the measurement of a unit of energy. Second processor 16 is connected to first processor 14 . As will be explained in greater detail below, processor 16 receives the energy signal(s) and generates an indication signal representative of said energy signal. It will be noted again that meter 10 is a wide range meter capable of metering over a voltage range from 96-528V. The components which enhance such a wide range meter include the divider network 12 A- 12 C, which as previously noted are connected to receive the voltage component. The dividers generate a divided voltage, wherein the divided voltage is substantially linear voltage with minimal phase shift over the wide dynamic range, i.e. 96-528 Volts. A processing unit (processors 14 and 16 ) are connected to receive the divided voltage and the current component. The processing unit processes the divided voltages and the current components to determine electrical energy metering values. It will be appreciated from the following description that processors 14 and 16 require stable supply voltages to be operable. A power supply, connected to receive the voltage component and connected to processors 14 and 16 , generate the necessary supply voltages from the Phase A voltage component over the wide dynamic range. Power supply 20 could also run off of phase 8 and phase C voltages or a combination of the above. However, a combination embodiment would require additional protection and rectifying components. In relation to the preferred embodiment of meter 10 , currents and voltages are sensed using conventional current transformers (CT's) and resistive voltage dividers, respectively. The appropriate multiplication is accomplished in a new integrated circuit, i.e. processor 14 . Processor 14 is essentially a programmable digital signal processor (DSP) with built in multiple analog to digital (A/D) converters. The converters are capable of sampling multiple input channels simultaneously at 2400 Hz each with a resolution of 21 bits and then the integral DSP performs various calculations on the results. For a more detailed description of Processor 14 , reference is made to U.S. Pat. No. 5,555,508, which is incorporated herein by reference and which is owned by the same assignee as the present application. Meter 10 can be operated as either a demand meter or as a time-of-use (TOU) meter. It will be recognized that TOU meters are becoming increasingly popular due to the greater differentiation by which electrical energy is billed. For example, electrical energy metered during peak hours will be billed differently than electrical energy billed during non-peak hours. As will be explained in greater detail below, first processor 14 determines units of electrical energy while processor 16 , in the TOU mode, qualifies such energy units in relation to the time such units were determined, i.e. the season as well as the time of day. All indicators and test features are brought out through the face of meter 10 , either on LCD 30 or through optical communications port 40 . Power supply 20 for the electronics is a switching power supply feeding low voltage linear supply 22 . Such an approach allows a wide operating voltage range for meter 10 . In the preferred embodiment of the present invention, the so-called standard meter components and register electronics are for the first time all located on a single printed circuit board (not shown) defined as an electronics assembly. This electronics assembly houses power supplies 20 , 22 , 24 and 28 , resistive dividers 12 A- 12 C for all three phases, the shunt resistor portion of 18 A- 18 C, oscillator 34 , processor 14 , processor 16 , reset circuitry, EEPROM 35 , oscillator 32 , optical port components 40 , LCD 30 , and an option board interface 38 . When this assembly is used for demand metering, the billing data is stored in EEPROM 35 . This same assembly is used for TOU metering applications by merely utilizing battery 26 and reprogramming the configuration data in EEPROM 35 . The additional time-of-use billing data is stored in the internal RAM of processor 16 , which RAM is backed by battery 26 . Consider now the various components of meter 10 in greater detail. Primary current being metered may be sensed using conventional current transformers. The shunt resistor portion of devices 18 A- 18 C are located on the electronics assembly. The phase voltages are brought directly to the electronic assembly where resistive dividers 12 A- 12 C scale these inputs to processor 14 . In the preferred embodiment, the electronic components are referenced to the vector sum of each line voltage for three wire delta systems and to earth ground for all other services. Resistive division is used to divide the input voltage so that a very linear voltage with minimal phase shift over a wide dynamic range can be obtained. This in combination with a switching power supply allows the wide voltage operating range to be implemented. Referring briefly to FIG. 2 , each resistive divider consists of two 1 Meg, ½ watt resistors 50 / 52 , 54 / 56 and 58 / 60 , respectively. Resistors 50 - 60 are used to drop the line voltage at an acceptable watt loss. Each resistor pair feeds a resistor 62 , 64 and 66 , respectively. Resistors 62 - 66 are metal film resistors having a minimal temperature coefficient. This combination is very inexpensive compared to other voltage sensing techniques. Resistors 50 - 60 have an operating voltage rating of 300 Vrms each. These resistors have been individually tested with the 6 kV IEEE 587 impulse waveforms to assure that the resistance is stable and that the devices are not destroyed. Resistors 62 - 66 scales the input voltage to be less than 1 Volt peak to peak to processor 14 . Resistors 62 - 66 should be in the range of from about 100 ohms to about 1 K ohms to assure this maximum voltage and maintain maximum signal. On grounded, three wire delta systems, those components of the electronics assembly operating on logic voltage levels (including the battery connector) can be at an elevated voltage. In such situations, the two, 1 Meg resistor combinations ( 50 / 52 , 54 / 56 , 58 / 60 ) provide current limiting to the logic level electronics. The worse case current occurs during testing of a 480 V, 3 wire delta meter with single phase excitation. It will be appreciated that energy units are calculated in processor 14 primarily from multiplication of voltage and current. The preferred embodiment of processor 14 , referenced above as being described in U.S. Pat. No. 5,555,508, includes three analog to digital converters. The necessity for three converters is primarily due to the absense of voltage transformers, present in prior meters. The M37428 microcontroller 16 is a 6502 (a traditional 8 bit microprocessor) derivative with an expanded instruction set for bit test and manipulation. This microcontroller includes substantial functionality including internal LCD drivers (128 quadraplexed segments), 8 kbytes of ROM, 384 bytes of RAM, a full duplex hardware UART, 5 timers, dual clock inputs (32.768 kHz and up to 8 MHz), and a low power operating mode. During normal operation, processor 16 receives the 4.1472 MHz clock from processor 14 as described above. Such a clock signal translates to a 1.0368 MHz cycle time. Upon power fail, processor 16 shifts to the 32.768 kHz crystal oscillator 32 . This allows low power operation with a cycle time of 16.384 kHz. During a power failure, processor 16 keeps track of time by counting seconds and rippling the time forward. Once processor 16 has rippled the time forward, a WIT instruction is executed which places the unit in a mode where only the 32.768 kHz oscillator and the timers are operational. While in this mode a timer is setup to “wake up” processor 16 every 32,768 cycles to count a second. Consider now the particulars of the power supplies shown in FIG. 1 . As indicated previously, the off-line switching supply 20 is designed to operate over a 96-528 VAC input range. It connects directly to the Phase A voltage alternating current (AC) line and requires no line frequency transformer. A flyback converter serves as the basis of the circuit. A flyback converter is a type of switching power supply. As used herein, the “AC cycle” refers to the 60 Hz or 50 Hz input to power supply 20 . The “switching cycle” refers to the 50 kHz to 140 kHz frequency at which the switching transformer of power supply 20 operates. It will be noted that other switching cycle frequences can be used. Referring now to FIG. 4 , power supply 20 for use in electronic meters includes a transformer 300 having primary and secondary windings. The input voltage (Phase A Voltage) is provided to the primary winding so that current may flow therethrough. As will be appreciated from FIG. 5 , the secondary winding defines the output of the power supply. Referring back to FIG. 4 , a switching member 302 is connected to the primary winding of transformer 300 . Switching member 302 permits and prevents the flow of current through the primary winding. Switch member 302 is operable in response to a control signal, which control signal is generated by control circuit 304 . Controller 304 generates the control signal in response to a limit signal generated by the start/feedback circuit 306 in response to the output of power supply 20 . Voltage clamp 308 serves to limit the voltage applied to transformer 300 and switch 302 . Surge protection circuit 309 is provided at the input to protect against surges appearing in the Phase A voltage. Referring now to FIG. 5 , transformer 300 and switch 302 are shown in greater detail. It will be appreciated that switch 302 is a transistor. At the beginning of each switching cycle, transistor 302 “turns on”, i.e. becomes conductive, and magnetizes the core of transformer 300 by applying voltage across the primary 310 . At the end of each cycle, transistor 302 turns off and allows the energy stored in the core of transformer 300 to flow to the output of the power supply, which “output” can be generally defined by secondary 312 . Simultaneously, energy flows out of the bootstrap or tertiary winding 314 to power the control circuitry 304 . Feedback circuit 306 and controller 304 control the output of power supply 20 by varying the ON time of transistor 302 . Controller 304 will be described in greater detail in relation to FIG. 5 . Transistor 302 is connected through inverter 316 to receive the output of an oscillator formed from inverters 318 , 320 and 322 . It will be recognized that such inverters form a ring oscillator. The oscillator has a free-run frequency of 50 KHz. The ON time of transistor 302 may vary between 200 ns and 10 μs. The OFF time is always between 8 and 10 μs. During operation, the bootstrap winding 314 of transformer 300 (pins 10 and 11 ) powers controller 304 , but this power is not available until the power supply has started. The control circuit is a current-mode regulator. At the beginning of a switching cycle, transistor 302 is turned ON by the oscillator output. If left alone, transistor 302 would also be turned OFF by the oscillator output. Transistor 302 remains ON until the current in primary 310 of transformer 300 (pins 8 and 13 ) ramps up to the threshold current level I th represented as a voltage V th . As will be explained below, V th is generated by feedback circuit 306 . When the primary current of transformer 300 , represented as a voltage V, and sensed by resistor 326 , ramps up to the threshold level V th pin 1 of comparator 324 terminates the ON period of the oscillator by forcing the oscillator output HIGH, which output in turn is inverted by inverter 316 , shutting OFF transistor 302 . Transistor 302 then turns OFF until the next switching cycle. Since the V th indirectly controls the ON time of transistor 302 , controller 304 regulates the output voltage of the power supply by comparing the sensed current in transformer 300 to this threshold level. Transistor 362 and pin 7 of comparator 326 can disable the oscillator. Transistor 362 , described in greater detail in FIG. 7 , disables the oscillator when the line voltage exceeds 400 volts. Comparator 328 disables the oscillator when the controller 304 has insufficient voltage to properly drive transistor 302 . The voltage in controller 304 , V c , will be described in relation to FIG. 5 . Consider now feedback circuit 306 , shown in FIG. 6 . When connected to the Phase A Voltage, resistor 330 slowly charges capacitor 332 . The high value of resistor 330 and the 400 volt limit by voltage clamp 308 limit the power dissipation of resistor 330 . After a few seconds, capacitor 332 charges above 13 volts. Transistors 334 and 336 then provide positive feedback to each other and snap ON. Controller 304 can run for tens of milliseconds from the charge stored in capacitor 332 . Normally, power supply 20 will successfully start and begin to power itself in this period. If it fails to start, transistors 334 and 336 turn OFF when the charge across capacitor 332 drops below 8.5 volts and capacitor 332 again charges through resistor 330 . This cycle repeats until the supply starts. With high input voltages and without resistor 338 (FIG. 5 ), the current sourced by resistor 330 can hold the control and start-up circuits in a disabled state that does not recycle. When Capacitor 332 drops below 8.5 volts, resistor 338 places a load on the control circuit supply. This load insures that the start-up circuit recycles properly with high input voltages. As indicated above, when the primary current of transformer 300 sensed by resistor 326 ramps up to the threshold level V th , pin 1 of comparator 324 can terminate the ON period of the oscillator. When the voltage on capacitor 332 is less than 13 volts, zener diode 340 provides no voltage feedback. Under these conditions, the base-emitter voltage of transistor 336 sets the current threshold I th to about 650 mA. This maximum current limit protects transistor 302 , as well as those transistors in voltage clamp 306 , and prevents transformer 300 from saturating. As the voltage on capacitor 332 , which is representative of the output voltage of the supply, approaches the proper level, zener diode 340 begins to conduct and effectively reduces the current threshold, i.e. effectively reduces V th . Each switching cycle will then transfers less power to the output, and the supply begins to regulate its output. When the regulating circuitry requires ON times of transistor 302 less than about 400 ns, the current sense circuitry does not have time to react to the primary current of transformer 300 . In that case, the regulating circuit operates as a voltage-mode pulse width modulator. Resistor 342 ( FIG. 5 ) generates a negative step at pin 3 of comparator 324 at the beginning of each switching cycle. The regulator feedback voltage at pin 2 of comparator 324 , which contains little current information at the beginning of each switching cycle, translates the step at pin 3 into various input overdrives of comparator 324 , thereby driving the output of comparator 324 to a logic HIGH level. The propagation time of the comparator 324 decreases with increasing overdrive, i.e. as the negative step increases, and the circuit acts as a pulse width modulator. The negative step will increase due to the changing level of V th . Any leakage inductance between the bootstrap winding (pins 10 and 11 of transformer 300 ) and the output winding (pins 3 and 4 of transformer 300 ) causes inaccurate tracking between the voltage on capacitor 332 and the output voltage of the supply. This leakage inductance can cause poor load regulation of the supply. The bootstrap and output windings are bifilar wound; they are tightly coupled, have little leakage inductance, and provide acceptable load regulation. Since the two windings are in direct contact, the bootstrap winding requires Teflon insulation to meet the isolation voltage specifications. A 100% hi-pot test during manufacture insures the integrity of the insulation. Consider now the details of voltage clamp 308 , shown in FIG. 7. A 528 VAC input corresponds to 750 VDC after rectification. Switching transistors that can directly handle these voltages are extremely expensive. By using the voltage clamp of the present invention, relatively inexpensive switching transistors can be utilized. In power supply 20 , the switching member 302 is shut down during parts of the AC cycle that exceed 400 volts. The switching transistor, transistor 302 , in conjunction with two other transistors 344 and 346 , can hold off 750 VDC. During surge conditions, these three transistors can withstand over 1500 volts. In the preferred embodiment, transistors 302 , 344 and 346 are 600-volt MOSFETs. Because high-voltage electrolytic capacitors are expensive and large, this voltage clamp 308 has no bulk filter capacitor after the bridge rectifier 348 . Without a bulk filter capacitor, this switching converter must shut down during parts of the AC cycle. It intentionally shuts down during parts of the AC cycle that exceed 400 volts, and no input power is available when the AC cycle crosses zero. The 2200 μf output capacitor 350 (FIG. 5 ), provides output current during these periods. As discussed above, transistors 344 and 346 act as a voltage clamp and limit the voltage applied to switching member 302 . At a 528 VAC line voltage, the input to the clamping circuit reaches 750 volts. During lightning-strike surges, this voltage may approach 1500 volts. When the voltage at the output of bridge rectifier 348 exceeds 400 volts, zener diodes 352 and 354 begin to conduct. These diodes, along with the 33 KΩ resistors 356 , 358 and 360 , create bias voltages for transistors 344 and 346 . Transistors 344 and 346 act as source followers and maintain their source voltages a few volts below their gate voltages. If, for example, the output of bridge rectifier 348 is at 1000 volts, the gates of transistors 344 and 346 will be at approximately 400 and 700 volts respectively. The source of transistor 344 applies roughly 700 volts to the drain of 346 ; the source of 346 feeds about 400 volts to switching member 302 . Transistors 344 and 346 each drop 300 volts under these conditions and thereby share the drop from the 1000 volt input to the 400 volt output, a level which the switching converter 302 can withstand. As zener diodes 352 and 354 begin to conduct and as transistors 344 and 346 begin to clamp, transistor 362 turns ON and shuts down the switching converter. Although transistors 344 and 346 limit the voltage fed to the converter to an acceptable level, they would dissipate an excessive amount of heat if the switching converter 302 consumed power during the clamping period. When switching converter 302 shuts down, transistor 302 no longer has to withstand the flyback voltage from transformer 300 . Resistor 364 takes advantage of this by allowing the output voltage of the clamp to approach 500 volts (instead of 400 volts) as the input to the clamp approaches 1500 volts. This removes some of the burden from transistors 344 and 346 . Zener diodes 352 and 354 are off and the converter 302 runs when the output of bridge rectifier 348 is below 400 volts. During these parts of the AC cycle, the 33 KΩ resistors 356 , 358 and 360 directly bias the gates of transistors 344 and 346 . The voltage drop across transistors 344 and 346 is then slightly more than the threshold voltages of those transistors along with any voltage drop generated by the channel resistance of those transistors. During the off time of transistor 302 , about 10 μS, the 33 KΩ resistors can no longer bias the gates of transistors 344 and 346 . Diode 366 prevents the gate capacitance of transistors 344 and 346 and the junction capacitance of zeners 368 and 370 from discharging when transistor 302 is off. This keeps transistors 344 and 346 ON and ready to conduct when transistor 302 turns ON at the next switching cycle. If the gates of transistors 344 and 346 had discharged between switching cycles, they would create large voltage drops and power losses during the time required to recharge their gates through the 33 KΩ resistors. In the preferred embodiment, two 33 KΩ resistors are used in series to obtain the necessary voltage capability from 966 surface-mount packages. This power supply must withstand an 8 KV, 1.2×50 μS short-branch test. Varistor 372 , resistors 374 , 376 and 378 , and capacitor 380 protect the power supply from lightning strike surges. A 550 VAC varistor 372 serves as the basis of the protection circuit. It has the lowest standard voltage that can handle a 528 VAC input. The device has a maximum clamping voltage of 1500 volts at 50 amps. A varistor placed directly across an AC line is subject to extremely high surge currents and may not protect the circuit effectively. High surge currents can degrade the varistor and ultimately lead to catastrophic failure of the device. Input resistors 374 and 376 limit the surge currents to 35 amps. This insures that the clamping voltage remains below 1500 volts and extends the life of the varistor to tens of thousands of strikes. Resistor 378 and capacitor 380 act as an RC filter. The filter limits the rate of voltage rise at the output of the bridge rectifier. The voltage clamping circuit, transistors 344 and 346 , is able to track this reduced dv/dt. Current forced through diodes 382 , 384 and capacitor 386 ( FIG. 5 ) is also controlled by the limited rate of voltage rise. Resistors 374 and 376 are 1 watt carbon composition resistors. These resistors can withstand the surge energies and voltages. Resistor 378 is a flame-proof resistor that acts as a fuse in the event of a failure in the remainder of the circuit. The values of resistors 374 , 376 and 378 are low enough so that they do not interfere with the operation of the power supply or dissipate excessive amounts of power. Finally it is noted that resistors 388 and 390 act to generate the power fail voltage PF. By using the wide voltage ranging of the invention, a single meter can be used in both a four wire wye application as well as in a four wire delta application. It will be recognized that a four wire delta application includes 96V sources as well as a 208V source. In the past such an application required a unique meter in order to accomodate the 208V source. Now all sources can be metered using the same meter used in a four wire wye application. While the invention has been described and illustrated with reference to specific embodiments, those skilled in the art will recognize that modification and variations may be made without departing from the principles of the invention as described herein above and set forth in the following claims.

Methods and apparatus for supplying power for use in metering electrical energy over a wide range of voltages with a single meter are disclosed. The wide ranging meter includes a processing unit for processing divided input voltage and a current component in order to determine electrical energy metering values. The processing unit is operable in response to supply voltages. A power supply, connected to receive the undivided voltage component, generates the supply voltages over the wide dynamic range. It is especially preferred for the power supply to include a transformer having first, second and third windings, wherein the undivided voltage component is provided to the first winding and wherein the second winding defines the output of the power supply. A switching member is connected to the first winding for permitting and preventing the flow of current in response to a control signal. A control member generates the control signal in response to the output of the power supply. It is also preferred for the control signal to disable the witch member. It is further preferred for the power supply to include a voltage blocking clamp, connected to the transformer for blocking the voltage applied to the transformer. It is still further preferred for an oscillator to be used to generate an oscillating signal for switching the switching member ON and OFF so that the switching member is provided a substantially constant OFF time.

TECHNICAL FIELD OF INVENTION [0001] The invention relates to the infrastructure field, more specifically to sewage technologies. Even more particularly, the invention relates to providing a manhole for desert environments where temperatures can be very high and environmental conditions such as erosion exert different challenges on sewage infrastructure. BACKGROUND [0002] Urbanisation requires sewage systems, and to accommodate this need, various technologies related to manholes have been devised. [0003] A traditional manhole used in Finland is shown in FIG. 1 in accordance with the prior art. FIG. 1 shows the top view at the top of the page and side view at the bottom of the page. Traditionally the parts of concrete manholes below ground surface are in size 80 cm or 1 m for the diameter and are made of concrete cones 100 , typically of height 50 cm or 75 cm. Traditionally a manhole is built of several parts: bottom ring 110 , cone 100 and several adjusting rings 140 , 141 and 142 . The outlet pipe 120 leads the water to the rest of the sewage system. [0004] For adjusting the height of the manhole separate adjusting rings 140 , 141 and 142 on the top of the concrete cone 100 have been used. In most cases there has been a need for several adjusting rings, as is also shown in FIG. 1 where three adjusting rings 140 , 141 and 142 are exhibited. The height of the adjusting rings typically varies between 5 cm and 25 cm, and the number of rings used varies also. Typically sealing tape is used between the adjusting rings. Occasionally elastomeric sealing rings are also used. The manhole cover 130 is typically a cast iron solid cover, which also acts as a rainwater cover. [0005] The concrete cone 100 is typically of 80 cm or 60 cm or 1 m diameter. The height of the cone 100 is typically 50 cm or 75 cm. The concrete bottom ring 110 typically has a diameter of 80 cm-1 m. The concrete in both the cone 100 and the bottom ring 110 is made of sulfate resistant cement. [0006] One problem with the traditional solution of adjusting rings is that the joint between the adjusting rings 140 , 141 , 142 , or an adjusting ring 140 and the cone 100 is occasionally not water and soil proof. Further the adjusting rings may get easily broken during the building of manholes, and over operational lifetime of the manhole. In many cases there has been a need for replacing broken adjusting rings 140 , 141 and 142 during yearly repairs of the concrete manholes. [0007] FIG. 2 shows another manhole in accordance with the prior art. FIG. 2 shows the top view at the top of the page and side view at the bottom of the page. In one alternative way of building a manhole, traditional concrete cone 100 is replaced with a concrete cone 200 and a telescope pipe 250 . The telescope pipe 250 is made of PEH (High density polyethylene). Clear opening of the telescope pipe 250 and cast iron cover 230 is about 60 cm, i.e. the same as in traditional concrete cone 100 of FIG. 1 . Benefits of using the telescope pipe 250 are variable height adjustment and tightness against leaking water from the ground and soil. [0008] Further, in Finland roads are not paved with asphalt directly after installing water pipes and manholes. The heights of the manholes need to be adjusted during the building of the pavement, and telescope makes it easier and faster to adjust the height. Building of manhole with several parts i.e. a bottom ring 110 , cone 100 and several adjusting rings 140 , 141 and 142 is slower than with telescope cone 250 . In many cases there has been a need for replacing broken adjusting rings 140 , 141 , 142 during yearly repairs of concrete manholes 10 . Telescope 250 and concrete cone 200 reduces also the amount of repairs needed. Lifting the heavy concrete cone 200 has also been made safer with lifting wire instead of traditional lifting grabs. [0009] The concrete cone 200 is typically 80 cm or 60 cm or 1 m in diameter and has a matching PEH-pipe telescope and two circular ring seals 260 and 261 . [0010] The telescope 250 is used to set the cover 230 so that it matches the final ground level. The concrete in both the cone 200 and the bottom ring 210 is made of sulfate resistant cement. The outlet pipe 220 leads the water to the rest of the sewage system. [0011] FIG. 3 demonstrates a typical concrete manhole 30 in Arabia, from the United Arab Emirates. In the UEA manholes are casted on worksite. This is in contrast to Europe where most of the manholes are casted in concrete mills and are then transported to worksites for assembling. A typical problem with manholes in the UAE is that the soil sinks around manhole and the manhole becomes too high. The cover 330 , which is typically a ductile iron inlet frame and crate, is then elevated and the concrete sides 300 of the manhole are exposed. A concrete slab 370 has been sometimes placed under the manhole to try and stabilize it. The outlet 330 and the inlet 331 connect the manhole to the rest of the sewage system. [0012] In the Middle East cities of millions of people are being built on sandy deserts, and in the United States many states such as Texas and Arizona are experiencing rapid growth in urbanisation. These areas are so hot that the PEH with a melting point of 120 Celsius is suboptimal for sewage applications, because PEH at a temperature of 40-50 Celsius degrees begins to be closer to the physical parameters where it behaves like a fluid, which of course is harmful in these sewage applications. [0013] Building sewage systems in these areas is challenging because temperature variations can be quite high and the ground is not always of a stable composition, i.e. many times the ground is composed of sand that can be quite mobile over long time periods. [0014] It is also known in the prior art that manholes have been protected against earthquakes, e.g. in JP2000291034A which is cited here as reference. [0015] Clearly what is needed is a manhole solution that can be casted on work site and the on-site casted manhole should still be resistant to environmental change such as erosion and temperature changes over long time periods in a desert environment. SUMMARY [0016] The invention under study is directed towards a system and a method for effectively providing a manhole for very hot desert conditions that can be casted on site and has an extended, long stable operational lifetime in a desert environment. [0017] A further object of the invention is to present a manhole that is cheap to construct and easy to maintain in desert conditions. [0018] One aspect of the invention involves a manhole with a metal telescopic pipe arranged into a concrete cone, which is attached to a concrete manhole that has a concrete slab of large area underneath it. Inlets and outlets are connected to the concrete manhole. The concrete cone, manhole and slab can all be casted on the worksite, or only some of them may be cased on the worksite. The metal telescopic pipe has a diameter that matches the diameter of the concrete cone, and the interface between the concrete cone and the metal pipe telescope is sealed with heat resistant sealing rings. The metal telescopic pipe can be moved within the concrete cone so that the position of the cover of the manhole is matched to the ground level. [0019] Therefore, whenever a sand storm, desert wind or other form of erosion causes a change in the ground level, a maintenance engineer can quite simply adjust the manhole so that the cover does not protrude or fall short from the ground, but matches the ground level. [0020] Further, in desert environments the ground is more fluid, as the ground is more sand based than in those regions where it is rock based. Therefore in one aspect of the invention the soil sinks around the manhole just because the sand moves, e.g. underneath the concrete or asphalt that surrounds the manhole. This causes the manhole to protrude and create torsion or shear into the asphalt or concrete surrounding the manhole, as the asphalt or concrete is going down due to the escape of sand underneath and gravity, and the manhole cover is going up relatively, as the concrete cone is unaffected by the movement of the sand. In these situations, the inventive manhole can be easily realigned to have the cover of the manhole match the (now lowered) surface level of the ground in accordance with the invention by moving the telescopic pipe. [0021] A manhole in accordance with the invention comprises a telescope and a cover, wherein the telescope is arranged to adjust the height of the manhole cover from the ground and is characterized in that, said telescope is a metal pipe within a concrete cone with at least one seal arranged to seal the interface between the pipe and the concrete cone, said concrete cone is arranged to be attached to the manhole, and said metal pipe telescope is arranged to be moved within said concrete cone vertically to adjust the cover position to ground level. [0025] A method of constructing a manhole is in accordance with the invention and the said manhole comprises a telescope and a cover, wherein the telescope adjusts the height of the manhole cover from the ground and is characterized by the following steps, said telescope is a metal pipe and is placed within a concrete cone with at least one seal, sealing the interface between the pipe and the concrete cone, said concrete cone is attached to the manhole, and said metal pipe telescope is moved within said concrete cone vertically to adjust the cover position to ground level. [0029] If the inventive manhole has a very wide diameter, e.g. larger than 1 m or the manhole is very low in height or shallow in depth, the concrete cone is removed and the telescope is attached to the manhole directly. [0030] The inventive manhole has numerous advantages over the prior art. The inventive manhole is very resistant to environmental changes such as erosion and temperature changes over long time periods, thereby providing a good return on infrastructure investment by providing sewage service to populations in these environmentally challenged locations. The inventive manhole can be constructed on site from the elements, i.e. its parts can be casted on the worksite, and it can be maintained very easily on its site. If the ground level changes, it will take just five minutes for a maintenance engineer to fix the manhole to match the current ground level by simply moving the telescopic pipe in the manhole. [0031] In addition and with reference to the aforementioned advantage accruing embodiments, the best mode of the invention is considered to be a steel pipe telescope matched to two circular heat resistant sealing rings in a concrete cone. The concrete cone is attached to a concrete manhole with a heat resistant seal. The position of the concrete cone is stabilised by a large concrete slab at the bottom of the manhole. The cover of the manhole rests on the steel pipe telescope, and when the ground level changes, the steel pipe telescope can simply be repositioned within the concrete cone to match the changed ground level. There is a mechanical system for moving the telescope for example by turning a handle or a lever that makes it possible to adjust the telescope height without actually dismantling the manhole during yearly repairs. All concrete parts can be casted on-site, which means that preferably both the construction and the maintenance of the manhole happen at the installation site in the best mode. BRIEF DESCRIPTION OF THE DRAWINGS [0032] In the following the invention will be described in greater detail with reference to exemplary embodiments in accordance with the accompanying drawings, in which [0033] FIG. 1 demonstrates an embodiment of a prior art traditional manhole 10 . [0034] FIG. 2 demonstrates an embodiment of a prior art telescopic manhole 20 . [0035] FIG. 3 demonstrates an embodiment 30 of a prior art work site casted manhole currently used in desert conditions. [0036] FIG. 4 demonstrates an embodiment 40 of the inventive manhole. [0037] FIG. 5 demonstrates an embodiment 50 of the inventive method of constructing the manhole of the invention in desert conditions. [0038] FIG. 6 demonstrates an embodiment 60 of the inventive manhole where the manhole is low and/or flat or large in diameter. [0039] Some of the embodiments are described in the dependent claims. DETAILED DESCRIPTION OF EMBODIMENTS [0040] FIGS. 1 , 2 and 3 that depicted prior art were already discussed in the background section. [0041] FIG. 4 displays an inventive manhole 40 with a concrete cone 400 with a telescope pipe 450 for hot climate regions. The on worksite casted manhole 410 has both an outlet 420 and an inlet 421 in some embodiments, but may also have only one or the other of the inlet 421 or outlet 420 . [0042] The concrete cone 400 , or any other concrete parts of the manhole 40 , may either be precasted at a concrete mill before bringing it to the worksite, or it may be casted at the worksite. When a concrete cone 400 is precasted in a concrete mill, it is faster to assemble the manhole 40 on the worksite. However, casting the concrete cone 400 at the worksite may save transportation costs substantially in some embodiments. In some embodiments the concrete may be made from polymer concrete. This is preferable especially in desert conditions where the salt content of the ground/soil is higher than in rocky ground/soil. In some embodiments polymer and cement are mixed together in different compositions to make up a polymer-cement concrete in accordance with the invention. [0043] The concrete cone 400 is arranged to host a telescope pipe 450 made of metal, preferably steel in some embodiments of the invention. The concrete cone 400 with the steel telescope 450 is surprisingly suitable for hot climate regions, and is designed to solve the problem of flexible height adjustment on demand for the manhole, in case ground level sinks or rises. The manholes typically become too high while the soil sinks around them. The main benefit of concrete cone 400 with the telescope 450 is that the height of the manhole can be made to follow the ground level, if ground sinks around the manhole. [0044] During repairs a technician will simply just move the telescope 450 to a new position in the concrete cone 400 to provide a different height for the telescope 450 and the cover 430 . The movement of the telescope 450 can take place preferably vertically with the telescope 450 in the concrete cone 400 . Even with this relative movement of the ground and the manhole, the inventive manhole stays still tightly sealed and does not leak. In some embodiments where the concrete cone is detached or not yet mounted onto the manhole, the movement can of course take place in any direction, depending on how the concrete cone 400 is positioned at that time. [0045] In the inventive concrete cone 400 the telescope 450 material is chosen for the hot climate, and also the joining of the concrete cone 400 to the on worksite casted manhole 410 is different, and in some embodiments utilizes a heat resistant seal 462 , which is e.g. circumferential along the entire interface of the concrete cone 400 and the on worksite casted manhole 410 . Also, in some embodiments it is preferable to have the bottom slabs of the manholes, i.e. the concrete slab 470 casted on the worksite in accordance with the invention, which saves transportation effort and cost. In other embodiments of the invention the concrete slab 470 may be precasted at a concrete mill for quick installation at the worksite. [0046] The concrete cones 400 with steel telescopes 450 can be manufactured in concrete mills in some embodiments, but also on the worksite in other embodiments. The cover 430 is typically made of solid iron, and is a rainwater cover, in some embodiments of the invention. The concrete cone 400 is interfaced to the metal telescope 450 with two O-ring seals 460 , 461 which are preferably heat resistant in accordance with the invention in some embodiments. Other types of seals may also be used in accordance with the invention. [0047] The telescope 450 is used to match the cover 430 level to the ground level and thereby establish the goals of the invention. In one preferred embodiment there is a mechanical system 480 for adjusting the position of the metal pipe telescope 450 within the concrete cone 400 , for example by turning a lever or handle mechanically. This way the technician can adjust the position of the metal pipe telescope and the cover anytime he wants, simply by using the mechanical system 480 , and there is no need to dismantle any part of the manhole or use complicated tools to move the metal pipe telescope 450 . For example, a chain and a lever and/or a gearwheel, gear, cogwheel and/or a cog with a lever or handle can be utilized to transmit the mechanical energy provided by the technician to move the metal pipe telescope in some embodiments of the invention. For example in one embodiment, the technician rotates a handle, which rotates a gearwheel, which pulls or pushes a chain or a rope or a structure on the metal pipe telescope 450 , thereby moving the telescope 450 within the concrete cone 400 up or down. [0048] In some embodiments of the invention the metal pipe telescope 450 is coupled to the surrounding tarmac, asphalt, or other surface material surrounding the manhole cover. As the soil sinks, the surface material will also start to sink, thereby moving the metal pipe telescope 450 , which is coupled to the surface material. This way, there is no need to adjust the metal pipe telescope 450 by a repair technician, because the metal pipe telescope 450 dynamically adjusts its position to the demands of the environment. [0049] Naturally all aspects of the described manhole system 40 can be combined with the method 50 of constructing the inventive manhole in accordance with the invention. [0050] Quite clearly any feature or phase of the embodiment 40 may be readily combined with any feature or phase of any of the subsequent embodiments 50 and 60. [0051] FIG. 5 shows the method of constructing the inventive manhole as a flow diagram. The concrete parts needed in the construction, for example the concrete cone 400 , or any other concrete parts of the manhole 40 , may either be precasted at a concrete mill before bringing it to the worksite, or it may be casted at the worksite. When a concrete cone 400 is precasted in a concrete mill, it is faster to assemble the manhole 40 on the worksite. However, casting the concrete cone 400 at the worksite may save transportation costs substantially in some embodiments. In some embodiments the concrete may be made from polymer concrete. This is preferable especially in desert conditions where the salt content of the ground/soil is higher than in rocky ground/soil. In some embodiments polymer and cement are mixed together in different compositions to make up a polymer-cement concrete in accordance with the invention. [0052] In phase 500 the metal pipe telescope 450 is placed into the concrete cone 400 that forms the throat of the manhole. The sealing between the concrete cone 400 and the metal pipe telescope is made tight enough that the metal pipe does not move unless considerable external force is applied to it, (e.g. a man pushing on it very hard.) This is to make sure that the pipe does not mechanically drift due to gravity over long time periods. The heat resistant seals 460 , 461 are applied and adjusted so that the interface between the concrete cone and the metal pipe is established in this way in phase 500 . [0053] In phase 510 the concrete cone 400 is attached to the manhole 410 . If the concrete cone is precasted, it is simply placed over the manhole, mason over the manhole, or attached with the sealing element 462 , which is designed to make the interface between the concrete cone 400 and the manhole 410 water- and soil-proof. [0054] In phase 520 the metal pipe telescope position is adjusted so that the cover of the manhole is at the same level to the ground. This is achieved by just mechanically moving the metal pipe telescope to a new position. In some embodiments of the invention the metal pipe telescope 450 is attached with screws and/or bolts to the concrete cone 400 or some other adhesive structure or method that is easy to dismantle or detach during the time of repairs when the telescope needs to be moved. [0055] In some embodiments of the invention in phase 520 the metal pipe telescope 450 is coupled to the surrounding tarmac, asphalt, or other surface material surrounding the manhole cover. As the soil sinks, the surface material will also start to sink, thereby moving the metal pipe telescope 450 , which is coupled to the surface material. This way, there is no need to adjust the metal pipe telescope 450 by a repair technician, because the metal pipe telescope 450 dynamically adjusts its position to the demands of the environment. [0056] Quite clearly any feature or phase of the embodiment 50 may be readily combined with any feature or phase of any of the other embodiments 40 and 60. [0057] FIG. 6 shows an embodiment 60 of a low or a wide manhole, where there is no need for a concrete cone. This embodiment is typically used in situations where the diameter of the manhole is more than one meter, or the manhole is so low that the concrete cone does not fit into the manhole. The telescope pipe 650 is attached to a manhole 610 as shown in FIG. 6 . The telescope pipe 650 is preferably a metal pipe telescope, for example a steel pipe telescope. The seals 661 , 662 are typically O-ring seals, and are also arranged to lubricate and/or reduce friction similarly to ball bearings between the manhole 610 and the telescope pipe 650 when the telescope pipe is being moved. The seal 660 is typically a slightly larger seal, for example 2 cm*2 cm in size. The purpose of the seal 660 is specifically to block the entry of soil or water into the manhole 610 . [0058] Quite clearly any feature or phase of the embodiment 50 may be readily combined with any feature or phase of any of the other embodiments 40 and 60. [0059] The invention has been explained above with reference to the aforementioned embodiments and several commercial and industrial advantages have been demonstrated. The methods and arrangements of the invention allow the manhole to be very resistant to environmental changes such as erosion and temperature changes over long time periods, thereby providing a good return on infrastructure investment by providing sewage service to populations in environmentally challenged locations, such as desert locations. The inventive manhole can be constructed on site from the elements, i.e. its parts can be casted on the worksite, and it can be maintained very easily on its site. If the ground level changes, it will take just five minutes for a maintenance engineer to fix the manhole to match the current ground level by simply moving the telescopic metal pipe in the manhole, preferably with the mechanical system 480 , thus avoiding the need to dismantle any part from the manhole. [0060] Naturally all aspects of the described method 50 of constructing the inventive manhole can be combined with the inventive manhole 40 in accordance with the invention. [0061] The invention has been explained above with reference to the aforementioned embodiments. However, it is clear that the invention is not only restricted to these embodiments, but comprises all possible embodiments within the spirit and scope of the inventive thought and the following patent claims. REFERENCES [0000] JP2000291034A, Ishikawa Takashi, NIPPON MANHOOLE KOGYO KK, 2000

A manhole ( 40 ) for desert environments where temperatures can be very high and environmental conditions such as erosion exert different challenges on sewage infrastructure, the manhole including a steel pipe telescope ( 450 ) matched to two circular heat resistant sealing rings ( 460, 461 ) in a concrete cone ( 400 ). The concrete cone is attached to a concrete manhole ( 410 ) with a heat resistant seal ( 462 ). The position of the concrete cone is stabilised by a large concrete slab ( 470 ) at the bottom of the manhole. The cover ( 430 ) of the manhole rests on the steel pipe telescope ( 450 ), and when the ground level changes, the steel pipe telescope can simply be repositioned within the concrete cone to match the changed ground level. All concrete parts ( 400, 410, 470 ) can be casted on-site, which means that preferably both the construction and the maintenance of the manhole happen at the installation site.

BACKGROUND OF THE INVENTION 1. Origin of the Invention The invention described herein was made in the performance of work under a NASA Contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 STAT, 435; 43 USC 2457). 2. Related Applications This application is a continuation in part application of U.S. patent application, Ser. No. 259,208, filed Apr. 30, 1981, entitled STABLE DENSITY-STRATIFICATION SOLAR POND now abandoned, incorporated herein by reference. 3. Background Discussion The invention generally relates to solar energy collectors and more particularly to an optimized "natural" solar pond particularly suited for use in capturing and storing solar thermal energy for residential and industrial usage, and providing minimum environmental problems. DESCRIPTION OF THE PRIOR ART Solar ponds of the types generally known, utilize "natural" or artificial density stratification facilitated by salty solutions of different concentrations. When exposed to the sun, rays of solar energy progressively penetrate the pond's depth with attendant increase in thermal energy absorption. This heat-transfer mechanism normally results in a relatively hot, dense bottom solution disposed beneath a relatively cool, dilute upper solution. Density gradients in the pond's depth preferably are designed large enough to stabilize density currents resulting from temperature differences and buoyancy forces. Diffusion at the thermocline boundary layer is considered to be inevitable, particularly during long periods of operation. Additionally, use of salty solar ponds tends to be limited to those areas where there can be found near a point of utilization, high-salinity lakes, seas, swamps, marshes, and so forth, of little environmental use. In such instances, a portion of the salty water beds can be made to serve as a solar pond, particularly where proper concentration levels are maintained. Utilization of man-made salty brine solar ponds, of course, tends to be limited because of the overwhelming operational and maintenance costs involved in such usage, particularly when compared to the low overall efficiency ultimately achieved and environmental problems associated with brine ponds. The prior art is replete with disclosures of solar-pond collector systems. For example, during the course of a preliminary search conducted with respect to the instant invention, the following patents were discovered U.S. Pat. No. 3,077,190, P. S. Allen; U.S. Pat. No. 3,372,691, S. Shachar; U.S. Pat. No. 4,063,419, Garrett; U.S. Pat. No. 4,066,062, Houston; U.S. Pat. No. 4,086,958, Lindner et al.; U.S. Pat. No. 4,099,558, Bricard et al.; U.S. Pat. No. 4,121,567, Carson; U.S. Pat. No. 4,159,736, Denis et al. None of the references discovered during the course of the search disclose the invention hereinafter described and claimed. However, it is noted that the patent to Garrett U.S. Pat. No. 4,063,419, discloses a method for obtaining solar energy utilizing solar ponds which includes a broad concept of using a dense liquid, such as a brine for solar energy collection and a covering agent, such as a floating oil, or other immiscible fluid or surface-active reagent, as well as an evaporation-inhibiting film in order to minimize or prevent evaporation of the pond liquid. Moreover, the pond liquid may include a dye for enhancing solar thermal energy absorption. It also is noted, however, that the prior art, including the patent to Garrett, clearly fails to disclose a stable, density-stratification, non-brine, solar pond of simplified economic and practical construction, which tends to render such a device suitable for residential and industrial usages. It is therefore the general purpose of the instant invention to provide a solar thermal energy collector which is particularly designed for enhanced operational efficiency in residential and industrial environments, and in particular has improved power output and may be used efficiently for cooling as well as heating. OBJECTS AND SUMMARY OF THE INVENTION It is an object of the instant invention to provide a stable density-stratification solar pond and method for collecting solar thermal energy. It is another object to provide a solar pond, solar thermal energy collector designed for enhanced operational efficiency. It is another object to provide an improved solar pond having reduced requirements for continuous maintenance of fluid levels to compensate for evaporation and undesired interface diffusion. It is another object to provide an optimized, stable density solar pond for use in collecting and storing solar thermal energy for usage in low-temperature Rankine cycle power systems. It is another object to provide a natural, completely stable, density-stratification, non-brine, solar pond employing two immiscible fluids of different densities combined in a container simulating a cavity radiometer for enhancing the operational efficiency thereof. These and other objects and advantages are achieved through the use of a container characterized by a generally cylindrical upright interior the uppermost wall of said container having an upper conical segment within which there is defined a solar energy acceptance opening, and a body of liquid disposed within the container consisting essentially of two layers of immiscible, non-brine liquids of mutually differing densities having a boundary layer defined there-between. Some of the unique features of this invention are: (1) that the area of the opening to the surface area of the internal walls is in the range of 1/10 to 1/50, and the opening area is no greater than 50% of the projected area of the container; (2) that the upper liquid is substantially less dense than the lower liquid which is of a color which absorbs solar energy. The "projected area" of the container means the cross sectional area of a plane through the container which results in the maximum area. For example, if the container was a cylindrical sphere, the plane would be through the center of the sphere at the maximum diameter. Typically the upper liquid is at least 20% less dense than the lower liquid. Because of these combined features the pond of this invention is able to reach higher temperatures than conventional systems (for example, 207° F. for the pond of this invention compared to 170° F. for conventional ponds). Moreover, because the liquid is essentially salt free (non-brine), it does not present a pollution problem and is easy to maintain. DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a solar pond embodying the principles of the instant invention, which as shown includes a device powered by a solar pond for closing the acceptance apparatus thereof. FIG. 2 is a side elevational view of the solar pond shown in FIG. 1 with the solar panel removed for the sake of simplicity. FIG. 3 is a top plan view of the solar pond as shown in FIG. 1. FIG. 4 is a cross-sectional view taken generally along lines 4--4 of FIG. 3. FIG. 5 is a schematic view depicting the device, powered by the solar pond, for deploying a thermally-insulative layer over the solar energy acceptance aperture provided for the solar pond. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a solar pond, generally designated 10, embodying the principles of the instant invention. As shown in FIG. 1, the solar pond 10 includes an upright container 12 having a base segment 14 and a shroud segment 16. As best illustrated in FIG. 4, the internal surface of the base segment 14 is of a generally cylindrical configuration while the internal surface of the shroud segment is of a substantially frusto-conical configuration disposed in coaxial juxtaposition with the base segment. As a practical matter, the container 12 includes a planar bottom segment 18, FIG. 4. Of course, the base segment 14, the shroud segment 16, and the bottom segment 18 are integrally related to form an integral structure. Moreover, within the plane of truncation of the shroud segment 16, there is defined an opening, herein referred to as a solar energy acceptance aperture 20. This aperture is closed by a transparent cover 22 formed of a suitable material, such as thermoplastic polymers and the like. The cover 22 serves as a fluid-evaporation barrier, as well as a barrier to wind, trash, and the like, and is supported by an annular structure, herein referred to as a protective ring 24. The ring 24 circumscribes the opening 20 and is, in turn, supported in a suitable manner. The ratio of the area of the opening to the internal surface area of the base, shroud and bottom segments is within a range of 1/10-1/50. As the ratio approaches a ratio of 1/50, the pond 10 approaches a black-body configuration of a relatively large volume. Accordingly, the ratio of the areas aforementioned serve to dictate the efficiency of the pond, and the angles of the shroud segment need only to accommodate the establishment of a desired ratio. In this example, the projected area corresponds to the area of base of the container. Within the container 12, there is disposed a body 26 of immiscible liquids, generally designated 26, FIG. 4. This body of liquids 26 includes a lower liquid 28 which substantially fills the base segment 14 of the container 12, while there is deposited thereon, in a layered relationship therewith, therefore an upper liquid 30 of the body 26. The upper liquid 30 substantially fills the shroud segment 16 with an optimum height between 10 to 50% of the lower liquid. As a practical matter, a boundary layer 32 is defined between the upper and lower liquids 28 and 30, respectively. It is important here to note that the lower liquid 28 of the body 26 of liquids is of greater density than the upper liquid 30 thereof. To exemplify, the body 26 comprises two immiscible liquids which may, where so desired, include water, glycerol-water or ethyleneglycol-water mixtures or the like as the lower liquid, and oil of paraffin, mixed, and naphthene base, or synthetic fluids such as polyolefins, polyalkylene glycols, silicones, halogenated hydrocarbons or vegetable oils or the like as the upper liquid. Because of their relative immiscibility, relatively widespread availability, low cost, and non-toxicity, oil and water are particularly suited for usage in solar ponds. Brines of differing densities could be used to establish a thermal gradient, but they present serious pollution and maintenance problems and, therefore, are unacceptable. Additionally, it is preferred that the lower liquid 28 of the body 26 of immiscible liquid, comprises a water or water of a dark color. Such a color may be imparted thereto through the use of a black dye or any other soluable dye with high absorptivity to the solar energy spectrum. The second portion 30 of the body 26 should be substantially transparent to rays of solar energy with a low extinction coefficient to solar radiation wave lengths. Thus, the upper liquid will act as low absorber and high transmitter to short wavelengths of the solar spectrum band. Where so desired, a layer of insulation foam, such as may be employed as a blanket 34 about the periphery of the external surface of the container 12. Such is provided as desired in order to minimize thermal energy losses to ambient air, the ground, and the like. Also, where so desired, a thermally insulated cover 36 is provided for preventing loss of thermal energy through the solar energy acceptance opening 20. As a practical matter, the cover 36 is, where desired, formed of a flexible insulative material and stored on a reel 38 in a manner such that the cover 36 may be drawn across the opening 20 in the absence of impinging solar radiation, such as occurs during the night season. A cover typifying that which may be employed is illustrated in FIG. 5. As shown, the cover 36 is connected with spring-loaded take-up reels 40, via cables 42, which are so spring-biased as to draw the cover 36 toward the reels 40. However, as illustrated, a motor 44 is provided for driving a suitable shaft of the reel 38 in order to effect a winding of the cover 36 thereabout. Where so desired, the motor 44 is connected to a solar panel 46, via suitable leads not designated. Where so desired, the solar panel 46 may comprise a simple photocell for closing a circuit switch in order to complete an electrical circuit through the motor 44 to ensure operation of the pond as a solar absorber collector during the sunny hours, and actuate the motion of the cover 36 at night hours, for a complete unattended operation. It should be appreciated, however, that the panel 46, upon being energized by incident solar radiation, serves to energize the motor 44 for winding the cover 36 about the reel 38, against the forces applied by the reels 40 via the cables 42. In the event the solar panel 46 is shaded from incident solar energy, the motor 44 de-energizes for thus permitting the reel 40 to draw the cover 36 across the solar energy acceptance opening 20. Thus the solar pond 10 is maintained in a suitable condition for receiving solar energy, and yet is protectively covered for inhibiting loss of heat when shaded from incident solar radiation. In view of the foregoing, it should now be apparent to those familiar with solar ponds, their construction and usages and the like that the relative thicknesses of the first and second portions 28 and 30 of the body 26 of liquids, the index of refraction and transmissivity coefficients of the upper and lower density liquids, as well as the thermal and physical properties of the liquids and the color of the bottom, higher density fluid can be varied in a manner well within the skill of the art. Such variations, of course, tend to reduce convection currents at the boundary layer 32 while the thermal storage characteristics of the pond are enhanced. Moreover, through the use of the transparent cover 22, the immiscible liquids forming the first and second portions of the body 26 of liquid can be maintained in a calm condition for thus further reducing the chances of developing vertical convection currents. Finally, the pond is provided with a heat transfer system 50. As shown, an inlet 52 and an outlet 54 for a coil 56 circumscribing the lower portion of the pond is provided. Suitable fluids such as organic fluids known as R-11 and R-113 serve quite satisfactorily as both heat transfer fluid and as a working fluid for a low-temperature Rankine cycle system. OPERATION It is believed that in view of the foregoing description, the operation of the invention herein disclosed and claimed readily is apparent, however, in the interest of completeness, the operation of the invention herein disclosed and claimed is, at this point, briefly reviewed. With the solar pond 10 having deposited within the container 12 a body 26 of immiscible liquid, as hereinbefore described, the device is ready for operation simply by removing the cover 36, manually or mechanically. As rays of solar energy are accepted at the solar energy acceptance opening 20, solar rays characterized by relatively short wave lengths, 0.3-3 microns, penetrate the transparent upper liquid 30 of the liquid body 26, passing through the boundary layer 32. The solar thermal energy now is absorbed in the lower liquid 28 of the body 26 of immiscible liquids. Thus the temperature of the lower liquid 28 rises. As the temperature of the lower liquid 28 rises, it begins to radiate thermal energy, a small quantity of the radiation being of a wave length to which the upper liquid 30 of the body 26 is transparent, while a much larger quantity of the radiation is of a wave length to which the upper liquid 30 of the body 26 is opaque. Thus a major portion of the radiation is trapped in the lower liquid of the pond. Due to the differing densities of the first and second portions 28 and 30, respectively, of the body 26 of immiscible liquids, the upper and lower liquids 28 and 30 respectively tend to remain separated along the boundary layer 32. Of course, as the thermal energy of short wave lengths is radiated from the upper liquid 30 of the body 26 of immiscible liquids, the radiation strikes the internal surface of the shroud segment 16 and is re-reflected back toward the lower liquid 28 of the body 26 of liquids. Thus the thermal energy is, in effect, trapped due to the opacity of the body 26 as well as the geometry of the internal surfaces of the container 12, in much the same manner as radiation is trapped within the cavity of a black body. Consequently, the lower liquid 28 of the body 26 of immiscible liquids is, in operation, maintained as a "hot" fluid relative to the upper liquid 30 of the body. Thus solar thermal energy is trapped within the pond 10 and the energy thus stored is usable as thermal energy for heating, cooling, or power generation in residential and industrial usages. In order to utilize the thermal energy thus collected and stored, a suitable heat transfer fluid is circulated through the heat transfer system 50 for conveying thermal energy from the pond 10 to a system, such as a low-temperature Rankine cycle power system, not shown. In view of the foregoing, it is believed to be readily apparent that the solar pond 10 provides a practical solution to the problems heretofore encountered by those engaged in the design of devices and systems intended to function as solar thermal energy collectors.

A stable density-stratification solar pond 10 for use in the collection and storage of solar thermal energy including a container 12 having a first section 14 characterized by an internal wall of a substantially cylindrical configuration and a second section 16 having an internal wall of a substantially truncated conical configuration surmounting the first section in coaxial alignment therewith, the second section of said container being characterized by a base of a diameter substantially equal to the diameter of the first section and a truncated apex defining a solar energy acceptance opening 20. A body 26 of immiscible liquids is disposed within the container and comprises a lower portion 28 substantially filling the first section of the container and an upper portion 30 substantially filling the second section of the container, said lower portion being an aqueous based liquid of a darker color than the upper portion and of a greater density. A protective cover plate 36 is removably provided for covering the acceptance opening.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to magnetic recording and reproducing apparatus, and particularly to a magnetic head apparatus for use in high density recording and high efficiency reproduction. 2. Description of the Prior Art Known types of magnetic head apparatus widely used for magnetic recording and reproducing apparatus, such as video tape recorders or video sheet recorders, include: (1) A combination system which uses the same magnetic head or heads for both recording and reproducing; and (2) An individual system which uses separate heads for recording and reproducing. Recently developed magnetic recording media have a characteristic suited for recordings of high density, for example, a high coercive force to prevent a self-demagnetizing action due to the recording of high density and a rapid decrease in reproducing output. The video sensitivity of a magnetic recording medium adaptable for recording at a high density as noted above is predicted by the following equation, as described in the Collection of Dissertations For 5th Science Lecture On Applied Magnetism (Page 76 to Page 77, 9, 1973), ______________________________________Video sensitivity = 0.363 Bm* + 0.434 Br* / Bm +(λ = 2.2μ) 1.200 Hc* - 0.185 ΔHc* 1/2 + 0.168 d* + 0.169 REF* + 0.580______________________________________ The mark (*) signifies that the values are those for standard tape converted into decibells. Bm = Maximum magnetic flux density, Br = Residual magnetic flux density, Br/Bm = Squareness ratio, Hc = Coercive force, ΔHc/2 = The half width of the differential curve near at its Hc, which relates to the steepness of slope of B - H curve. REF = The reflected light intensity (45° to 45° ) from the surface of the sample. D = Thickness of magnetic layer, λ = Recording wave length. The video sensitivity, from the above equation, increases at the coercive force becomes high, but the magnetic medium requires an intense recording magnetic field, with the result that saturation of the magnetic flux density of the recording system head cannot be ignored. As a consequence, the actual video sensitivity tends to be lower in value than the predicted value obtained from the equation. For example, FIG. 1 shows the relationship between coercive force of a given magnetic recording medium and the video sensitivity for a recording wave length of 2.2μ, in which curve A represents the predicted value of sensitivity, curve B represents the actually measured value of sensitivity using an alloy head (Sendust) for recording and reproduction, and curve C represents the actually measured value of sensitivity using a ferrite head (Mn-Zn system ferrite) for recording and reproduction. The difference between measured sentivity values, resulting from the use of different kinds of heads, is due to the differences in the maximum magnetic flux density. (Bm) and in the physical characteristics inherent in the different materials. Table I below shows the magnetic and physical characteristics of various magnetic head materials. TABLE 1__________________________________________________________________________MAGNETIC AND PHYSICAL CHARACTERISTICS OF MAGNETIC HEAD MATERIALS ALLOY MATERIAL FERRITE* Conven- high Single Hot Hot tional Perm- Alphenol Sendust(al- density crystal press press sintered alloy (Alperm) pheceil) ferrite ferrite ferrite ferrite ferrite Unit__________________________________________________________________________ Ni 79 Al 16 Al 5.5 NiO 11 MnO 23 MnO 15 NiO 18.9 NiO 19Composition Mo 4 Fe 84 Si 10.0 ZnO 22 ZnO 7 ZnO 15 ZnO 13.6 ZnO 13.5 Wt % Fe 17 Fe 84.5 Fe.sub.2 O.sub.3 67 Fe.sub.2 O .sub.3 70 Fe.sub.2 O.sub.3 70 Fe.sub.2 O.sub.3 Fe.sub.2 O.sub.3 67.5 DC 20,000 3,000 30,000 850 2,000 2,000 250 200μo 4MH.sub.z 40↑ 30↑ 60↑ 550 1,100* 800 250 200Bm 8,700 18,000 11,000 3,900 4,500 4,000 4,000 2,500 gaussHc 0.05 0.04 0.05 0.4 0.1 0.1 1 1.5 OeSpecificresistance 55×10.sup.-6 140×10.sup.-6 80×10.sup.-6 107 >1 >102 >106 107 Ω.cmCurie 460 400 500 125 230 150 350 250 ° CtemperatureVicker' 132 350 500 600 600 650 750 400hardnessDensity 8.72 6.5 8.8 5.3 5.1 5.1 5.3 4.5 g/cm.sup.3__________________________________________________________________________ ↑Sample ring thickness 0.2 mm *(110) face ring In video recorders using a combination system magnetic head apparatus the head assembly is often designed with an efficient reproducing system as the main criteria. Consequently, magnetic heads composed of a ferrite system magnetic material are widely used because they provide a high conversion efficiency due to their high permeability, μo. However, their coercive force is high and their maximum magnetic flux density. is low, resulting in an inability to achieve high density recording. On the other hand, when the magnetic head composed of an alloy system magnetic material is used, high density recording can be achieved but reproduction occurs at a low conversion efficiency because of the low permeability μo. Consequently there is a distinct disadvantage if the same head is used for recording and reproducing. In recorders having an individual system magnetic head apparatus the recording system magnetic head apparatus is composed of an alloy system magnetic material and the reproducing system magnetic head apparatus is composed of a ferrite system mangetic material. The recording and reproducing of heads are not mounted on the same mechanism as rigidly with respect to each other. Heretofore, such individual systems have been very complicated, and thus expensive, due to the requirement for precision in video magnetic recording because of the separate mounting. The information tracks must be precisely positioned such that the recording and reproducing head mechanisms place their respective heads in the identical positions relative to the information tracks. This has only been accomplished by complicated adjustment mechanisms. SUMMARY OF THE INVENTION It is an object of the present invention to overcome the disadvantages noted above with respect to prior art apparatus. The object of the present invention may be achieved by providing a magnetic recording and reproducing apparatus characterized by the provision of a magnetic head device wherein the same supporting means supports a recording magnetic head made of an alloy system magnetic material and a reproducing magnetic head made of a ferrite system magnetic material in fixed physical relation to each other. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the relationship between coercive force of a magnetic recording medium and video sensitivity. FIG. 2 is a top plan view of a helical scanning rotary head system of a video recorder according to one embodiment of the present invention. FIG. 3 is a front view of FIG. 2. FIG. 4 is a perspective view partially cutaway of a magnetic sheet recorder according to a modified embodiment of the present invention. FIG. 5 is a diagram of a control system for controlling the rotary position of the magnetic heads. FIG. 6 is a pictorial representation showing the relative positions of the information signals and the control track signals on a magnetic medium. FIG. 7 is a diagram of apparatus for controlling the lateral position of the magnetic heads. DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIGS. 2 and 3, there is shown a rotary head device 1, which comprises, two drums 2 disposed one above the other to form a horizontal slit S therebetween, a cross arm 4 rotatable in the direction of the arrow A by means of a rotary shaft 3 extending through the central portion of the drums 2, and two recording magnetic heads 5 and two reproducing magnetic heads 6, said recording and reproducing magnetic heads being mounted on the upper surfaces at the tips of the arm 4. The recording magnetic heads 5 are made of an alloy system magnetic material, for example, such as a Sendust system or alphenol system alloy material, and the reproducing magnetic heads 6 are made of a ferrite system magnetic material, for example, such as single crystal ferrite or high density ferrite. Further, the aforesaid recording magnetic heads 5 can be thin film magnetic heads which are made of the alloy system magnetic material described above, a conductor such as Cu and an insulator such as SiO, by using several techniques such as electroplating, vacuum evaporating, cathod sputtering, photo etching and the like as disclosed in the Journal of IEEE Transations on Magnetics, vol. Mag-11, No. 5,1218, September 1975. The slit S is designed to have the minimum width necessary to accomodate the arm 4 provided with the recording magnetic heads 5 and reproducing magnetic heads 6. The foremost surfaces of the recording magnetic heads 5 and reproducing magnetic heads 6 mounted on the arm 4 are each slightly extended past the outer surface of the drums 2 and are alternately arranged on the same circumference in a spaced relation of 90° from the center of the arm 4. Guide rollers 7 are provided on the opposite sides of the drums 2 so that a magnetic tape 8 may travel in the direction of the arrow B while being helically wound around substantially half the circumference of the drum 2. To record video signals, the magnetic tape 8 is caused to travel at a constant speed in the direction of the arrow B while being wound in helical fashion around more than half of the circumference of the drums 2 and the slit S. The arm 4 is rotated at a constant speed in the direction of the arrow A and at the same time the two recording magnetic heads 5 disposed in a spaced relation of 180 degrees from the center of the arm 4 are excited to magnetically record video signals on the magnetic tape 8. The magnetic tape 8, to which a high coercive force must be imparted for purposes of recording the video signals thereon with high density can have the signals recorded thereon by the recording heads 5 which will not saturate because of their high maximum magnetic flux density Bm. Next, in reproducing the video signals, the magnetic tape 8 travels and the arm 4 is rotated in a manner similarly to that for video recording, as previously mentioned, and at the same time, the two reproducing magnetic heads 6 are excited to reproduce the video signals magnetically recorded on the magnetic tape 8. It will be appreciated that in order that the reproducing magnetic heads 6 accurately trace a recorded track when the magnetic heads are switched from the recording system to the reproducing system, a 90° phase shifter added to a known servo circuit for a rotary head device can be used to control the phase of the servo system. A well-known servo system for a turn head apparatus is shown generally in FIG. 5 with the addition of a phase shifter 60. For the head according to the present invention, the phase shifter 60 is switched into the circuit during the reproducing mode. When recording, a standard turn speed reference signal (RS) is applied to a servo circuit 58, which drives a motor 64 in the direction of arrow A at a speed based on RS. The motor rotates the recording heads 5 and the reproducing heads 6, which are turned with a direction of the arrow A. The turning speed of the motor or heads 5 is detected by a conventional encoder comprising disc 54 and detector 56. The detected speed is fed back for combination with RS to correct the difference between RS and the rotational speed. Also, the output signal from a pulse generator, comprising disc 50 and detector 52, constitutes the control track pulse and occurs twice each revolution in accordance with the phase of the heads 5. The control track signal is recorded on the lower part of the tape by means of the control truck head 71. As seen in FIG. 6, the information signal, recorded by means of the heads 5 is recorded in tracks 70 and the control track signals are recorded at 72. When the system is switched to the reproducing mode, the RS signal is supplied to the servo circuit 58 via the phase shifter 60. Also the output signal of the encoder is fed back for combination with RS in order to correct the difference. At the same time, the recorded control track signal is reproduced, by means of the control track head 71, and applied to the phase shifter 60 along with the output signal of the control track pulse generator. The time difference between the two pulse signals is detected and the speed control signal is phase shifted to cause said two pulse signals to be 90° out of phase. This results in the reproducing heads 6 being in phase with the information tracks 70. Accordingly, the phase of heads 5 is delayed by 90° from the control track signal recorded on the tape. The phase of reproducing heads 6 is delayed by 90° from the phase of heads 5 and is turned in accordance with the control track signal. Since the reproducing magnetic heads 6 have an extremely high permeability μo, the system has a electromagnetic conversion effeciency and exhibits a high SN ratio in the output. FIG. 4 illustrates a modified form of embodiment according to the present invention, which is a video sheet recorder. A magnetic head device as indicated at 41 comprises an arm 42 movable toward the center of a magnetic sheet 45, a recording magnetic head 43 mounted on the under-surface of the arm 42 and made of an alloy system material, for example, such as Sendust system or alphenol system material, and a reproducing magnetic head 44 also mounted on the undersurface of the arm 42 and made of a ferrite system magnetic material, for example, such as single crystal ferrite or high density ferrite material. The recording magnetic head 43 and reproducing magnetic head 44 mounted adjacent to each other on the under-surface of the arm 42 are disposed along the rotating direction D of the magnetic sheet 45 and in parallel to each other in a suitable spaced relation, E. The reference numeral 46 denotes a base plate of the magnetic sheet recorder, and numeral 47 denotes a rotary shaft extending through a central hole 46a of the base plate 46. The shaft 47 is rotated in the direction of the arrow D with a central portion of the magnetic sheet 45 held by the upper end surface of shaft 47 and a screw 48. When the magnetic sheet 45 mounted on the rotary shaft 47 is rotated in the direction of the arrow D, it floats on an air cushion. Thus there is a slight clearance F between the upper surface of the base plate 46 and the magnetic sheet 45. As the sheet 45 rotates, the magnetic surface of the sheet comes into accession or contact with the foremost surfaces of the recording magnetic head 43 and reproducing magnetic head 44. The recording magnetic head 43 is excited and the arm 42 is moved in the direction of the arrow C to record video signals on the magnetic sheet 45. For reproduction the reproducing magnetic head 44 is excited and allowed to trace the recorded track. It is noted that since the reproducing magnetic head 44 is displaced by an amount E from the recording magnetic head 43, an arrangement is made so that such a displacement may be corrected prior to commencement of reproduction by the arm 42. An example of a system for providing the correction is shown in FIG. 7. Although only arm 42 is illustrated it will be apparent that the other three arms are adjusted by the same mechanism shown. An input command circuit 96, for setting the exact position of record head 43, applies a command signal via preset counter 92 to a controller 90. The controller 90 controls motor 88, which turns gear 84, which rotates ball screw 82 relative to bearings 86. Arm 42 thereby moves in accordance with the command in counter 92. A coded disc attached to the ball screw and a detector make up an encoder 80, which feeds position signals to the counter 92. Movement stops when the head 43 is at the position determined by the input command signal from circuit 96. During the reproduction mode the system inserts circuit 94, which add an amount, +E, to the command signal. Consequently the reproducing head will be positioned exactly adjacent the recorded track. Thus the invention disclosed above permits the advantages of an individual system without the normally attendant complex mechanisms for interchanging the record and reproduce head mechanisms. This is accomplished by providing at least one record head and at least one read head, fixedly positioned relative to one another on the same head supporting mechanism, the record head having a maximum magnetic flux density Bm substantially higher than that of said read head, and said read head having a permeability μo substantially higher than that of said record head.

A magnetic recording and reproducing apparatus provided with a magnetic head device comprising a supporting means having a recording magnetic head made of an alloy system magnetic material and a reproducing magnetic head made of a ferrite system magnetic material. The recording and reproducing heads are fixed relative to one another thereby eliminating the need for completely separate head mechanisms and for complex mechanisms to reliably interchange the positions of the two heads relative to the recording medium.

FIELD OF THE INVENTION This invention relates generally to apparatus for collecting blood and in particular to an apparatus for agitating collected blood to prevent coagulation thereof and for weighing the collected blood. 1. Background of the Invention Supplies of blood are maintained by hospitals and other medical facilities for use in blood transfusions. Blood is collected from individual donors at hospitals, clinics and at other sites via mobile blood collection units. Because blood supplies are in great demand, it is important to be able to maintain the quality of blood supplies between the time they are collected and the time they are actually used in transfusions. Typically, the collected blood is mixed with an anticoagulant to prevent the blood from coagulating. 2. Description of the Prior Art According to prior practice, blood taken from a donor is introduced via a flexible flow tube into a flexible bag or pouch. The pouch is often placed on an agitator device, which rocks the pouch back and forth to mix the blood and anticoagulant. Conventional agitating devices are motorized, and require a source of electrical current as well as relatively expensive electrical components. The agitator may have a scale associated therewith for weighing the collected blood and for cutting off the blood flow to the pouch when a preset weight has been collected. One problem associated with electrically powered agitators is that a suitable source of electrical power may not be available, such as when blood is collected via mobile collection units. Electrically operated agitators are also relatively large and expensive because of the electrical components required. The need therefore exists in the art for a blood agitator device which can be operated without electrical power. OBJECTS OF THE INVENTION It is therefore the principal object of the present invention to provide an improved blood agitator device. Another object of the invention is to provide a blood agitator device which is operable without electrical power. Yet another object of the invention is to provide a blood agitator device suitable for use in a mobile blood collection unit. Still another object of the invention is to provide a device for measuring the weight of blood collected from a donor and for terminating the blood collection process when a predetermined weight of blood has been collected. A further object of the invention is to provide a pneumatically operated blood agitator device. SUMMARY OF THE INVENTION These and other objects are accomplished in accordance with the present invention wherein an agitator device is provided for agitating a liquid, such as blood, collected in a container, such as a flexible blood storage bag. The device includes a base member and a support member for the container, which is pivotally mounted with respect to the base member. In one aspect of the invention the agitating device includes means for biasing the support member to a first tilted position relative to the base member and an expandable member positioned beneath the support member. The expandable member is inflated and expanded in response to the introduction of pneumatic pressure therein to overcome the biasing means to move the support member to a second tilted position, opposite from the first tilted position, relative to the base member. The expandable member is contracted in response to the release of the pneumatic pressure to allow the biasing means to move the support member to the first position. The support member is alternately moved between the first and second tilted positions by the alternating expansion and contraction of the expandable member to agitate the blood in the container. In one embodiment the device further includes means for introducing pneumatic pressure into the expandable member to inflate the expandable member and for allowing the pneumatic pressure to be released therefrom. In another embodiment the means for introducing pneumatic pressure into the expandable member includes a bellows and a flexible tube coupled between the bellows and the expandable member. The bellows is compressible for transmitting pneumatic pressure through the tube to the expandable member and is inflatable for relieving pneumatic pressure from the expandable member. The bellows is preferably a flexible squeeze bulb operated by hand squeezing action, such as by a blood donor when blood is being collected in the container. When the donor squeezes the bellows, pneumatic pressure is introduced into the expandable member to overcome the biasing means, thereby tilting the support member to the second tilted position. When the donor releases his grip on the bellows, the pneumatic pressure in the expandable member is released back through the flexible tube into the bellows, thereby allowing the expandable member to contract and allowing the biasing means to return the support member to the first tilted position. By alternately squeezing and releasing the bellows, the support member, with the container of blood positioned thereon, is tilted back and forth to agitate the blood for mixing with the anticoagulant in the container. In another aspect of the invention the agitating device is adapted for controlling the amount of blood being collected in the container via a flexible flow tube extending between the donor and the container. The device includes means for applying tension to the tube so that at least a portion of the tube is maintained relatively straight; means for exerting a compressive force on the relatively straight portion of the tube to close off the tube and terminate the flow of blood to the container; means for monitoring the weight of blood being collected from the donor; latch means for holding the compressive force exerting means out of contact with the relatively straight portion of the tube until a predetermined weight of blood has been collected in the container; and means for releasing the latch means when the predetermined weight of blood has been collected to allow the compressive force exerting means to engage the relatively straight portion of the tube to close off the tube and terminate the blood flow. In one embodiment the tension applying means includes a retaining member having a pair of aligned slots for receiving the tube therethrough, such that the relatively straight portion of the tube is disposed between the slots. In another embodiment, the compressive force exerting means includes a piston member which is biased toward a first position for closing off the tube when the piston member is in the first position. The piston member further includes a notch therein. The latch means include a bar member having a first end portion which mates with the notch to maintain the piston member in a second position, opposite from the first position, such that the piston member is held out of contact with the tube. The first end portion is disengaged from the notch to release the piston member when sufficient force is exerted on a second end portion of the bar, opposite from the first end portion, to tilt the first end portion away from the piston member. In the preferred embodiment, the means for monitoring the weight of collected blood includes a tension spring, a first end of which is fixed and a second end of which, opposite from the first end, is movable away from the first end when the spring is under tension. Means is provided for adjusting the tension of the spring in accordance with a predetermined weight of blood to be collected. A platform member is coupled to the second end of the spring and is movable therewith for exerting a downward force on the second end portion of the bar sufficient to tilt the first end portion thereof out of engagement with the piston member when the weight of blood which has been collected causes the second end of the spring and the platform member to move downwardly, such that the platform member contacts the second end portion of the bar. BRIEF DESCRIPTION OF THE DRAWINGS Further objects and advantages of the invention will be apparent from the detailed description and claims when read in conjunction with the accompanying drawings wherein: FIG. 1 is a perspective view of a blood agitator and weighing device according to the present invention; FIG. 2 is a side elevation view of a top portion of the agitator device, illustrating the top portion thereof in different tilted positions for agitating blood collected in a container positioned on top of the agitator device; FIG. 3 is a sectional view, taken along the line 3--3 in FIG. 4, showing internal components of the agitator device; and FIG. 4 is a sectional view, taken along the line 4--4 in FIG. 3, showing internal components of the agitator device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the description which follows, like parts are marked throughout the specification and drawings, respectively. The drawings are not necessarily to scale and in some instances proportions have been exaggerated in order to more clearly depict certain features of the invention. Referring to FIG. 1, a liquid agitator device 10 according to the present invention includes a base member 12 and a support member 14, which is pivotally mounted with respect to base member 12. Support member 14 has a top panel 16 for supporting a liquid container, such as a flexible blood storage bag 18. The support member 14 has a rectangular recess 14A centered about a support panel 16A for receiving the flexible storage bag 18. Base member 12 includes a plurality of bottom feet 20 for stabilizing device 10 on a support surface. Base member 12 further includes a retaining member 22, projecting outwardly from an end surface of base member 12. Retaining member 22 includes two relatively flat, parallel projections having respective aligned slots 24 for receiving respective portions of a flexible tube 26 as tube 26 passes through retaining member 22. Slots 24 are tapered downwardly and inwardly for tightly gripping tube 26 to exert tension thereon and maintain a portion of tube 26 disposed between aligned slots 24 in a relatively straight orientation. As shown in FIG. 1, one end of tube 26 is coupled to bag 18 and the opposite end of tube 26 is coupled to a blood donor (not shown). A piston member 28, having an extension portion 30, is provided for closing off tube 26 to terminate the flow of blood from the donor to bag 18 when a predetermined weight of blood has been collected. Piston member 28 is shown in its extended position in FIG. 1 for allowing blood to flow through tube 26. When piston member 28 is retracted, such that extension portion 30 engages the portion of tube 26 disposed between slots 24, tube 26 will be "pinched off" by the inwardly directed force exerted by piston member 28. The operation of piston member 28 will be described in greater detail hereinafter, with respect to FIG. 4. Device 10 also includes a handle 32 to facilitate transport of device 10. Referring to FIGS. 1 and 2, base member 12 includes an upwardly extending member 34 on each side thereof for pivotally mounting support member 14. Each member 34 has a threaded opening therein for receiving a screw 36 or other attachment member to pivotally mount support member 14 with respect to base member 12. Support member 14 can thus be tilted about a horizontal axis substantially coincident with the respective major axes of mounting screws 36. A compression spring 38 is coupled between an inner surface 40 of support member 14 and a mounting plate 42 fixed to base member 12. Spring 38 is positioned between the horizontal tilt axis and a first end 44 of support member 14 when spring 38 is extended (i.e., not under compression), spring member 38 will bias support member 14 toward a first tilted position at which first end 44 of support member 14 is higher than second end 46 of support member 14, as shown in FIG. 2. A flexible, inflatable bladder 48 is disposed between inner surface 40 and mounting plate 42 and also between the horizontal tilt axis and second end 46. When support member 14 is in the first tilted position, such that first end 44 is elevated above second end 46, the bladder 48 is in a substantially collapsed position. When pneumatic pressure is introduced into the bladder 48 sufficient to overcome the bias of spring 38, the bladder 48 will be expanded to tilt support member 14 to a second tilted position, opposite from the first tilted position. In a second tilted position, second end 46 is elevated above first end 44, as also shown in FIG. 2. Pneumatic pressure is introduced into the bladder 48 by means of a squeeze bulb 50 and a pneumatic tube 52. Tube 52 is coupled at one end to bulb 50 and at the opposite end to a nipple 54 projecting outwardly from support member 14. As shown in FIG. 2, another tubular member 56 connects nipple 54 and bladder 48, thereby pneumatically interconnecting bulb 50 and bladder 48. During the blood collection process, the blood donor is typically placed in a reclining position and a needle is inserted into a vein in the donor's arm to draw blood therefrom. The needle is connected to a flexible flow tube, which in turn is connected to a bag where the blood is collected. To expedite the blood collection process, the donor typically opens and closes the hand on the particular arm in which the needle has been inserted in order to increase the blood flow through the flow tube into the bag. In accordance with the present invention, the blood donor will alternately squeeze and release bulb 50. The squeezing action will compress bulb 50 to transmit pneumatic pressure to the bladder 48, thereby causing the bladder 48 to expand and tilt support member 14 to the second tilted position. When support member 14 is in the second tilted position, the spring bias of spring 38 is overcome and spring 38 is substantially compressed. When the donor releases his grip on bulb 50, pneumatic pressure will flow from the bladder 48, through tube 52, back into bulb 50, thereby expanding bulb 50 for the next squeeze cycle. The release of pneumatic pressure from the bladder 48 permits it to collapse and allows spring 38 to return to its extended position, thereby tilting support member 14 back to the first tilted position. One skilled in the art will appreciate that as the donor alternately squeezes and releases bulb 50, support member 14 will be tilted gently back and forth to agitate the blood collected in bag 18 and mix the collected blood with the anti-coagulant inside bag 18. Referring to FIGS. 3 and 4, the agitator device 10 includes means for monitoring the weight of blood or other liquid being collected. The monitoring means includes a tension spring 58 having a relatively flat plate 60 interposed between adjacent turns of spring 58, near the top part of spring 58. A threaded bolt 62 extends through an opening in an elongated arm member 64 and through the top part of spring 58 and terminates substantially at plate 60. Plate 60 maintains the top portion of spring 58, which is disposed between plate 60 and arm member 64, in a fixed position, while allowing the portion of spring 58 below plate 60 to be stretched and compressed depending upon the weight of the liquid in the bag on top of support member 14. An adjustment nut 66 is threadedly connected to bolt 62 for adjusting the tension of spring 58 in order to calibrate device 10, as will be described in greater detail hereinafter. Spring 58 is disposed within a housing 68, which is movable up and down along with spring 58. Support member 14 and an upper portion 70 of base member 12 are also movable along with housing 68. Spring 58 is coupled to a bottom portion 72 of housing 68 by means of a cotter pin 74 or other suitable attachment member. A pair of counterweights 76 are mounted on respective shafts 78 for dampening the movement of housing 68 and also to offset variations in the tension of spring 58, which may be caused by changes in humidity, air pressure and other environmental conditions. Counterweights 76 are pivotally mounted on their respective shafts 78 by means of spring rods 80, which extend through respective openings in housing 68. As the weight of the liquid collected in the container on top of support member 14 increases, spring 58 will stretch and housing 68 will move in a downward direction, thereby causing counterweights 76 to rotate upwardly to counteract the downward movement of spring 58 and housing 68. In accordance with the present invention the flow of liquid to the container disposed on top of support member 14 is cut off after a predetermined weight of liquid has been collected. A substantially Z-shaped bar 82 has a first end portion which mates with a notch disposed in piston member 28, as best seen in FIG. 4. A spring member 84 biases the first end portion of bar 82 into contact with the notch to hold piston member 28 in an extended position, as shown in FIG. 4. A compression spring 86 is disposed on piston member 28 for biasing piston member 28 toward a retracted position. Bar 82 exerts a force acting along the major axis of piston member 28, which is sufficient to overcome the spring bias of spring 86 and hold piston member 28 in the extended position. A second end portion of Z-shaped bar 82, opposite from the first end portion thereof, is pivotally mounted within base member 12, beneath bottom portion 72 of housing 68. As the weight of the liquid being collected increases, housing 68 will move downwardly along with spring 58 until bottom portion 72 of housing 68 contacts the second end portion of bar 82. The force exerted by bottom portion 72 on the second end portion of bar 82 will pivot bar 82, such that the first end portion thereof will move upwardly and out of mating engagement with the notch in piston member 28. When bar 82 is disengaged from piston member 28, the spring bias of spring 86 will retract piston member 28, such that extension portion 30 of piston member 28 will contact tube 26 (see FIG. 1) and close off the flow of blood to the container on top of support member 14. Device 10 is calibrated for a predetermined weight of blood to be collected by adjusting the tension of spring 58. As previously mentioned, an adjusting nut 66 is threadedly connected to bolt 62 above arm member 64. Tightening nut 66 by rotating it in a clockwise direction will cause bolt 62 to move upwardly to increase the tension on spring 58, thereby increasing the weight of liquid which must be collected before piston member 28 is released. Similarly, loosening nut 66 by rotating it in a counterclockwise direction will cause bolt 62 to move downwardly to decrease the tension on spring 58, thereby decreasing the weight of liquid which must be collected before piston member 28 is released. After the initial adjustment of spring tension on spring 58 is accomplished by means of adjustment nut 66, fine adjustment is achieved by means of an adjusting screw 88. Adjusting screw 88 is threadedly received within an opening in arm member 64 at the opposite end thereof from the end at which bolt 62 extends through arm member 64. Arm member 64 is pivotally mounted at a central portion thereof to a fixed portion of base member 12, as indicated at 90 and as best seen in FIG. 3. Turning adjusting screw 88 to the left (counterclockwise) will rotate arm member 64 upwardly (i.e., counterclockwise when viewed from the perspective of FIG. 3), thereby increasing the tension on spring 58. Similarly, turning screw 88 to the right (clockwise) will rotate arm member 64 downwardly (i.e., clockwise when viewed from the perspective of FIG. 3), thereby decreasing the tension on spring 58. Calibration is achieved by placing a known weight equal to the desired weight of blood to be collected on top of support member 14 and adjusting the tension on spring 58, first by turning nut 66 clockwise to tighten nut 66 and increase the tension on spring 58 until bottom portion 72 of housing 68 contacts the second end portion of bar 82, but does not yet exert sufficient downward force to disengage the first end portion of bar 82 from piston member 28. Further adjustment is made by turning screw 88 counterclockwise to further increase the tension on spring 58 until bar 82 is disengaged from piston member 28, at which point screw 88 is "backed off" approximately 1/2 turn clockwise. The above-described procedure has been found to provide a relatively precise calibration of device 10 for the predetermined weight of blood to be collected. Various embodiments of the invention have been described in detail. Since it is obvious that many changes in and additions to the above-described preferred embodiment can be made without departing from the nature, spirit and scope of the invention, the invention is not limited to said details, except as set forth in the appended claims.

A blood agitating and weighing device includes a base member and a support member, pivotally mounted with respect to the base member, for journally supporting a container, such as a flexible blood storage bag. A spring member is provided for biasing the support member to a first tilted position relative to the base member and a flexible bladder is positioned beneath the support member. The bladder is expandable in response to the introduction of pneumatic pressure therein to overcome the bias of the spring member to move the support member to a second tilted position relative to the base member. The bladder is contracted in response to the release of pneumatic pressure to allow the spring member to move the support member back to the first position. The support member is therefore alternately moved between the first and second positions by the alternating expansion and contraction of the bladder to agitate the blood in the container.

FIELD OF THE INVENTION The present invention relates generally to yarns and processes for producing yarns and, more specifically, to a composite yarn and a process for producing a composite yarn comprising a multifilament yarn and staple fibers. BACKGROUND OF THE INVENTION The basic concept of spinning fibers is centuries old. Spinning staple fibers into useful threads and yarns improved their overall strength, to a limited extent, and allowed the final yarn to be spun with varying degrees of thickness, strength, etc. With the advent of synthetic textile fibers, the possibility arose for producing continuous filament yarns with greater strength and more durability than those from staple fibers, and also no shrinkage. Unfortunately, the look and feel of fabrics produced solely with synthetic yarns do not meet the high standards demanded by a significant portion of the textile market, especially the clothing industry. In an attempt to produce yarns with the positive qualities of both staple fibers and synthetic filaments, composite yarns have been manufactured for many years. A well-known method of spinning both homogenous and composite yarns has been ring spinning, which has several advantages. For example, ring spinning produces a strong yarn of high quality, with a low capital investment per spindle. Unfortunately, ring spinning is a comparatively slow process, capable of producing only about 10 to 25 meters of yarn per minute, which greatly increases the cost of the final product. Still, since no other previously known process could produce the strength or feel of ring-spun yarn, this process is still used when the demand for its strength and feel justifies the high costs involved. Other spinning machines and methods have been developed in more recent years in an attempt to produce a composite yarn with the quality of a ring-spun yarn. Some of these methods include open-end, vacuum, and air-jet spinning, which are capable of output capacities exceeding 10 to 25 times that of ring spinning. One such method is disclosed in U.S. Pat. No. 4,069,656 to Arai etal. Arai describes a process for producing yarns at high speed by feeding a bundle of short fibers along with fine multifilament yarn into a twisting device. The filament yarn is fed at sufficiently low tension and at a faster speed than the fibers such that the fine yarn becomes wrapped around the short fibers. Supposedly, the non-twisted configuration of the fiber bundle provides a good feel to the yarn. However, the alternating twist of the yarn in this patent precludes its use as a sewing thread, where tear-resistance and high uniformity are required. Additionally, thread made from filament yarns such as that disclosed by Arai have smooth outer surfaces, which causes them to be easily pulled from seams. To date, high quality goods have consistently used mainly ring-spun staple fibers for thread, but as mentioned above, this greatly increases the costs. Another attempt to create a high-quality composite yarn is disclosed in U.S. Pat. No. 4,866,924 to Stahlecker. A fiber component is first formed by a drawn sliver that is pre-strengthened by false twist spinning. A filament yarn is then taken up with the fiber component onto a spool for subsequent spinning, using a conventional spinning method. According to the patent, when high demands are made on the composite yarn, such as are made on ring-spun staple fibers, it is necessary to rewind the yarn and clean it out so that defects, such as thick or thin points, can be removed. Obviously, the cost involved in rewinding the yarn, among other deficiencies, makes this yarn unacceptable as a viable, cost-effective alternative to ring-spun yarn. In U.S. Pat. No. 4,928,464 of Morrison, a core filament yarn is tensioned and dragged over the sharp edge of a nonconductive material. After releasing the tension, a crimp develops on the filaments. The crimped filament yarn is then fed into a vacuum spinning device along with nipped sliver or roving. The crimp of the core filaments causes the individual filaments to repel each other and allows the sliver or roving to become partially intermixed with the core during spinning. When the core filaments enter the spinner, they are only tensioned sufficiently to carry them through the apparatus. In the final product, the fibers, while partially intermixed with the core, are relatively loosely spun around the core, allowing them to slide along it and expose the filament yarn beneath. This degrades the look and feel of any fabric produced with the yarn. This sliding phenomenon is known to occur with many existing composite yarns. The vacuum spinning disclosed by Morrison is faster than conventional ring spinning, but is still considerably slower than air-jet spinning. In vacuum spinning, a shaft having multiple holes is rotated while suction is applied to the holes. This rotating shaft is capable of a rotational speed much less than that caused by air jets. An effective air-jet spinner is disclosed in U.S. Pat. No. 4,497,167 to Nakahara et al. The dual-nozzle system provides high-speed, uniform spinning. The only necessary tension on the entering fibers is that sufficient to carry the fibers through the nozzles. The type of air-jet spinner disclosed by Nakahara can also be applied to composite spinners, such as the "High-Speed Type Murata Jet Spinner," manufactured by Murata Machinery, Ltd., Kyoto, Japan. This machine is capable of producing 300 meters per minute, while maintaining uniform spinning. Nevertheless, with any of the known air-jet spinners, it has been impossible to achieve a tight enough wrapping of fibers around a core to prevent any slippage or pilling. SUMMARY OF THE INVENTION The present invention is directed to a method for manufacturing yarn of staple fibers and continuous multifilament yarn. The multifilament yarn is first heavily pretensioned before entering a spinning chamber where it is co-spun with the staple fibers. The tension is relaxed after passing through the spinning chamber to allow the filaments of the yarn to expand and form a matrix to which the staple fibers can adhere. The expanded filaments cause the staple fibers to be tightly wound around and anchored to the core, preventing any slippage or excess pillage and providing for superior "feel" by preventing the core filaments being exposed. To the contrary, it has been the practice in the prior art to feed the multifilament yarn at little or no tension in order to improve intermixing with the staple fibers. However, it was surprisingly discovered that pretensioning the textured yarn sufficiently to temporarily remove any crimp prior to spinning dramatically increases the quality and durability of the composite yarn produced. During spinning, the sliver may be applied with an opposite spin direction to that of the continuous multifilament yarn to create a more balanced yarn. Materials knit from the resulting yarn have high ball burst strength, low random pill test results, and low shrinkage (on the order of 2-3%). Accordingly, one aspect of the present invention is to provide a two-component composite yarn, including a staple fiber component and a filament yarn component that is tensioned before being spun. Another aspect of the present invention is to provide a method of co-spinning a continuous filament yarn and staple fibers in a spinner to produce a two-component composite yarn. The method includes the steps of feeding a sliver or roving of the staple fibers through a drafting apparatus to prepare a continuous bundle; pretensioning the filament yarn; combining the continuous bundle of fibers and the filament yarn downstream of said drafting apparatus; and feeding them into a spinner. Still another aspect of the present invention is to provide a yarn produced according to the above method. These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following detailed description of the preferred embodiment in conjunction with a review of the appended drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of a yarn spinning apparatus constructed according to the present invention; FIGS. 2A-2D are partially magnified schematic views of a yarn at various stages of production according to the present invention; FIG. 3 is a magnified perspective of an end of a completed composite yarn according to the present invention; FIGS. 4-8 show graphical representations of the force elongation curves for various example yarns described below. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, it is to be understood that such terms as "forward", "rearward", "left", "right", and the like are words of convenience and are not to be construed as limiting terms. Now referring to the drawings, as best seen in FIG. 1, there is shown a schematic representation of a yarn spinning apparatus, generally designated 10, constructed according to the present invention. Spinning apparatus 10 includes a drafting frame 12 to which a staple sliver 14 is fed in the direction of arrow "A". In the drafting frame 12, a staple sliver 14, such as from cotton, is drawn to the desired size, as is known in the art. The drafting frame 12 preferably has bottom rollers 16,18,20,22 and top pressure rollers 26,28,30,32. Top and bottom aprons 34,36 are driven by rollers 32,22, respectively, also as is known. The resulting staple fibers 14 are prepared to be spun. A stretch textured multifilament S-twist (clockwise twist) yarn 50, such as a stretch "S"-twist 70 denier/34 filament yarn, is withdrawn from yarn supply 38 through guide 40, pretensioning device 42 and ceramic thread guide 44 located downstream of the aprons and before top and bottom nip rollers 46,48. The pretensioning device 42 is preferably an adjustable spring-loaded cymbal tension device that the multifilament yarn 50 is passed through so that the yarn can be adjusted to provide the best results. Other known tensioning devices may be employed. As seen in FIG. 2A, when the stretch textured "S" twist multifilament yarn 50 is removed from its supply, it is in a crimped state with inter-filament gaps caused by the random abutment of adjacent crimps. The gaps also cause the yarn 50 to have an overall average thickness in its relaxed state substantially exceeding the average thickness in its tensioned state. While only a small number of filaments are shown in FIGS. 2A-2D, it is to be understood that the preferred multifilament yarn is comprised of as many filaments as are necessary to produce the desired final size composite yarn. The yarn filaments shown in FIG. 2A exit in that crimped, expanded state from the yarn supply 38 to the pretensioning device 42. After the pretensioning device, the multifilament yarn is pulled sufficiently taut such that the crimp is temporarily substantially removed from the filaments, as seen in FIG. 2B. The multifilament yarn 50 is preferably a synthetic material, such as nylon, rayon, acrylic, polypropylene, spandex, acetate, asbestos, glass filament, polyolefin, carbon fiber, and quartz multifilament yarn. As seen in FIG. 2B, the overall average thickness has been significantly reduced by tensioning yarn 50 and temporarily removing the crimp. The multifilament yarn 50 then enters between the top and bottom nip rollers 46,48, which maintain the tension on the yarn 50. The tension is similarly maintained between the first nip rollers 46,48 and second nip rollers 52,54. At the first nip rollers, the yarn 50 and the staple fibers 14 are combined and fed into the air-jet zone. The air-jet zone is preferably constructed as shown in U.S. Pat. No. 4,497,167. The cotton staple sliver 14 and the core filament yarn 50 enter the first air jet 56 where the loose cotton staple is wrapped around the core yarn 50 with a clockwise rotation, as seen in FIG. 2C. It is to be understood that the cotton staple fibers completely surround the core yarn 50 and that the illustrated single spread-out winding 14 in FIG. 2C, is shown exaggerated, for illustration purposes. Thus, the wrapped staple fibers 14 are shown spaced in order to show the condition of the underlying core. Similar false spacing is shown in FIG. 2D. Preferred covering by the cotton fibers 14 of the core yarn 50 is shown in FIG. 3. After leaving the first air-jet 56, the combined filament and staple fibers then pass into the second air jet 58 where the combined yarn is subsequently twisted with a counterclockwise rotation. Since in this case, the core filament yarn was processed with a "S" twist (clockwise twist), the core's rotational orientation is opposite the "Z" twist (counterclockwise twist) orientation of the composite yarn, which leads to a stable final yarn with reduced twist. The direction of the two air jets 56,58 can be reversed if the core yarn has been processed with a "Z" twist (counterclockwise twist). The core twist can also be matched to the composite yarn twist to produce a covered yarn with increased twist. Upon leaving the second air jet 58, the combined yarn passes through second nip rollers 52,54, with the core still under tension and looking much like FIG. 2C. Although exaggerated, the space between the loops of the surrounding staple fibers and the core illustrates how easily the fibers 14 might move along the core 50 if the yarn were completed at this point. After the second nip rollers 52,54, the core 50 is finally released from its tension, causing it to expand to a state similar to FIG. 2A. However, it is now wrapped with and constrained by the surrounding staple fibers 14, which bind the core and prevent it from reaching its fully expanded state and thus, simultaneously become more taut themselves. This tight wrapping, unattainable through conventional spinning alone, increases the frictional engagement between the staple fibers 14 and the core 50, greatly reducing slippage. The core filaments also tend to enter, but not penetrate, between the surrounding fibers, further increasing the anchoring of the outer fiber cover to the inner core. It will be understood that the final overall thickness of the core 50 after expanding is still less than the original thickness, since it is constrained by the staple fibers. The process and products according to the present invention will become more apparent upon reviewing the following detailed examples: EXAMPLE 1 10 samples of 70 denier 34 filament stretch textured multifilament yarn were tested on a Uster TENSORAPID testing machine. Results of the tests are shown in FIG. 4 and in Table 1 below. As can be seen, the yarn is a relatively high-strength high-elongation yarn with little variation in elongation or B-force (breaking force). The curve shown in FIG. 4 is typical of what would be expected for modern man-made multifilament yarns. TABLE 1______________________________________ X V______________________________________Elongation 29.23% 7.36B-Force 414.20 g 2.91Tenacity 53.31 RKM 2.91Work to Rupture 3499.60 g*cm 12.89______________________________________ where X is the mean, V is the coefficient of variation, RKM represents grams per Tex (1000 meters), and g*cm represents grams per 100 meters. EXAMPLE 2 10 samples of a 70 d/34 stretch texture yarn and stable fiber composite yarn were tested on an Uster testing machine. The stretch textured filament yarn was pretensioned at 20 gms. Results of the tests are shown in FIG. 5 and in Table 2 below. As can be seen, the yarn is a relatively low-strength, low-elongation yarn with an undesirable large variation in elongation. The curve shown in FIG. 5 is typical of what would be expected for an incompletely intermixed composite yarn. TABLE 2______________________________________ X V______________________________________Elongation 4.38% 69.80B-Force 240.90 g 5.43Tenacity 7.34 RKM 5.43Work to Rupture 364.74 g*cm 90.21______________________________________ EXAMPLE 3 10 samples of a 70 d/34 filament stretch textured yarn and stable fiber composite yarn were tested similarly as above. The filament yarn was pretensioned at 50 gms. Results of the tests are shown in FIG. 6 and in Table 3 below. As can be seen, this yarn also is a low-strength, low-elongation yarn with a large variation in elongation between individual fibers. The curve in FIG. 6 is also typical of what would be expected for an incompletely intermixed composite yarn. However, the "knee" of the curve at about 6% elongation and the lower range of variation in elongation compared to Example 2 indicates that increasing the tension improves the quality of the yarn. TABLE 3______________________________________ X V______________________________________Elongation 6.78% 15.63B-Force 290.66 g 9.66Tenacity 8.86 RKM 9.66Work to Rupture 529.19 g*cm 23.31______________________________________ EXAMPLE 4 10 samples of a 70 d/34 filament stretch textured filament yarn and staple fiber composite yarn were tested as above. The filament yarn was pretensioned at 75 gms. Results of the tests are shown in FIG. 7 and in Table 4 below. As can be seen, this composite yarn is a higher-strength, higher-elongation yarn with a smaller range of variation in elongation than any of the previous examples. The curve is as expected for a substantially completely intermixed composite yarn. Note the well defined "knee." TABLE 4______________________________________ X V______________________________________Elongation 12.61% 5.77B-Force 370.91 g 7.73Tenacity 11.31 RKM 7.73Work to Rupture 984.71 g*cm 14.06______________________________________ EXAMPLE 5 10 samples of a 70 d/34 filament stretch textured yarn and staple fiber composite yarn were tested as above. The filament yarn was pretensioned at 150 gms. Results of the tests are shown in FIG. 8 and in Table 5 below. As can be seen, this yarn is also a higher-strength, higher-elongation yarn with a small variation in elongation. The curve shown in FIG. 8 is typical of what would be expected for an intermixed composite yarn. Note the well defined "knee." However, the Tenacity value is slightly lower than for Example 4 indicating additional pretensioning would not produce a better quality yarn. TABLE 5______________________________________ X V______________________________________Elongation 16.21% 6.37B-Force 301.36 g 8.47Tenacity 9.19 RKM 8.47Work to Rupture 1147.74 g*cm 17.82______________________________________ EXAMPLE 6 150 d/34 filament stretch textured yarn was evaluated for testing as above. While not actually tested, it is expected that if tested the results of the tests would be as shown in Table 6 below. Elongation and tenacity are material dependent properties and are expected not to change with denier. However, B-force, which is dependent on denier, is expected to about double. TABLE 6______________________________________ X V______________________________________Elongation 29.23% 7.36B-Force 818.40 g 2.91Tenacity 53.31 RKM 2.91______________________________________ EXAMPLE 7 150 d/34 filament stretch textured yarn and staple fiber composite yarn were evaluated for testing as above. If it is assumed that the filament yarn was pretensioned at 150 gms, the results shown in Table 7 below are anticipated to closely follow the results of the 70 d filament yarn pretensioned at 75 gms (see Table 4 for comparison). Elongation and tenacity are material dependent properties and are expected not to change with denier. However, B-force, which is dependent on denier, is expected to about double when comparing 70 denier to 150 denier. TABLE 7______________________________________ X V______________________________________Elongation 12.61% 5.77B-Force 741.82 g 7.73Tenacity 11.31 RKM 7.73______________________________________ It is to be understood that in place of the cotton staple fibers, similar staple fibers such as rayon, polypropylene, acetate, asbestos, nylon, polyester, acrylic, wool, cashmere, alpaca, mohair, linen, silk and polyolefin could be substituted. Fabric Advantages Fabrics produced with yarns according to the present invention display several advantages with respect to other fabrics, such as 100% cotton and conventional poly/cotton blends. These advantages include less pilling and higher ball burst strength. The fabrics also have high uniformity and even cover, due to the reduced slippage of the cover staple fibers and the evenness of the filament core yarn. In the embodiment of the yarn in which the core has the reverse twist of the cover fibers, there is less fabric biasing. This reduces the tendency of hems or other garment parts to torque or bias. The fabrics produced with yarns according to the invention also exhibit lower shrinkage, i.e., less than 2-3%, compared to typical cotton fabric, which exhibits 12-14% shrinkage. Therefore, there are lower finishing costs, since no formaldehyde-based resin is necessary to decrease the shrinkage as with the cotton fabric. Therefore, the composite yarns of the present invention and fabrics produced with them exhibit the positive qualities of filament yarns and staple fibers, while avoiding the negative qualities of both. It is to be understood that while the embodiments shown and described are fully capable of achieving the above objects and advantages, these embodiments are shown and described only for the purpose of illustration and not for the purpose of limitation.

A composite yarn comprises a staple fiber component that is formed by drafted sliver. A filament yarn component is formed by applying tension to a filament yarn initially having a crimp such that the crimp is temporarily substantially removed. The staple fiber component and the pretensioned filament yarn component are combined by spinning while the tension is applied to the filament yarn.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a marine engine cooling system and, more particularly, to a cooling system that is provided with a siphon inhibiting device to alleviate problems in marine engine cooling systems that can possibly result due to heated water reversing its normal flow direction when the engine is off. 2. Description of the Prior Art Those skilled in the art of marine propulsion systems are aware of many different types of engine cooling systems. Typically, a water pump is used to draw water from the body of water in which the marine propulsion system is operated. The water is then conducted through a series of passages and into thermal communication with various heat producing components, such as the engine and its exhaust manifolds. After being used to remove heat from the heat producing components, the water is then typically combined with an exhaust stream from the engine and conducted overboard back into the body of water from which it was drawn. U.S. Pat. No. 5,980,342, which issued to Logan et al on Nov. 9, 1999, discloses a flushing system for a marine propulsion engine. The flushing system provides a pair of check valves that are used in combination with each other. One of the check valves is attached to a hose located between the circulating pump and the thermostat housing of the engine. The other check valve is attached to a hose through which fresh water is provided. Both check valves prevent flow of water through them unless they are associated together in locking attachment. The check valve attached to the circulating pump hose of the engine directs a stream of water from the hose toward the circulating pump so that water can then flow through the circulating pump, the engine pump, the heads, the intake manifold, and the exhaust system of the engine to remove seawater residue from the internal passages and surfaces of the engine. It is not required that the engine be operated during the flushing operation. U.S. Pat. No. 5,334,063, which issued to Inoue et al on Aug. 2, 1994, describes a cooling system for a marine propulsion engine. A number of embodiments of cooling systems for marine propulsion units are disclosed which have water cooled internal combustion engines in which the cooling jacket of the engine is at least partially positioned below the level of the water in which the water craft is operating. The described embodiments all permit draining of the engine cooling jacket when it is not being run. In some embodiments, the drain valve also controls the communication of the coolant from the body of water in which the water is operating with the engine cooling jacket. Various types of pumping arrangements are disclosed for pumping the bilge and automatic valve operation is also disclosed. U.S. Pat. No. 6,004,175, which issued to McCoy on Dec. 21, 1999, discloses a flush valve which uses only one moving component. A ball is used to seal either a first or second inlet when the other inlet is used to cause water to flow through the valve. The valve allows fresh water to be introduced into a second inlet in order to remove residual and debris from the cooling system of the marine propulsion engine. When fresh water is introduced into a second inlet, the ball seals the first inlet and causes the fresh water to flow through the engine cooling system. When in normal use, water flows through the first inlet and seals the second inlet by causing the ball to move against a ball seat at the second inlet. Optionally, a stationary sealing device can be provided within the second inlet and a bypass channel can be provided to allow water to flow past the ball when the ball is moved against the ball seat at the first inlet. This minimal flow of water is provided to allow lubrication for the seawater pump impeller if the seawater pump is operated during the flushing operation in contradiction to recommended procedure. U.S. Pat. No. 6,135,064, which issued to Logan et al on Oct. 24, 2000, discloses an improved drain system. The engine cooling system is provided with a manifold that is located below the lowest point of the cooling system of the engine. The manifold is connected to the cooling system of the engine, a water pump, a circulation pump, the exhaust manifolds of the engine, and a drain conduit through which all of the water can be drained from the engine. The patents described above are hereby expressly incorporated by reference in the description of the present invention. In certain types of marine propulsion systems, water can drain and thereby create a siphon effect that draws water from other components of the cooling system. When the engine is turned off, cooling water in the outboard drive drains downward to the water line. This draining initiates a siphon effect which, in turn, draws cooling water from the heated engine in a backwards direction through the cooling circuit. The heated water from the engine then enters and remains in the fuel/water heat exchanger which, in most cases, is a coaxial heat exchanging device. The heated water in this fuel/water heat exchanger causes the liquid fuel to increase in temperature and, in certain cases, vaporize. When the operator of a marine vessel then tries to restart the engine, this partially vaporized fuel in the fuel/water heat exchanger is difficult to displace with the typical electric fuel pump that is normally used. As a result, vapor lock can be experienced. It would therefore be significantly beneficial if a means could be provided that prevents the siphon effect from draining the water from the cooling system soon after the pump is deactivated. It would be further beneficial if the siphon inhibiting means could also allow later draining of the cooling system. SUMMARY OF THE INVENTION A marine cooling system made in accordance with the present invention comprises a pump, a heat producing component, and a conduit connected between the pump and the heat producing component. In a marine propulsion system, the heat producing component can be the engine itself or associated devices, such as the exhaust manifolds and the exhaust elbows. A preferred embodiment of the present invention also comprises a valve connected in fluid communication with the conduit between the pump and the heat producing component. A ball or poppet is disposed within a cavity of the valve, with the valve having a first port and a second port. In certain embodiments of the present invention, a poppet valve can be used instead of the ball. Throughout the description of the present invention it should be understood that the use of the term “ball” should be understood to describe the use of either a ball or a poppet valve. The first and second ports of the valve allow water to flow into and out of the valve during operation of the engine and during draining. The valve is configured to receive a stream of water into the first port from the pump and then pass the stream of water serially through the cavity and the second port to the heat producing component. The present invention further comprises a seal which is responsive to movement of the ball within the cavity and located between the first port and the cavity in order to inhibit water flow through the cavity toward the pump. The valve is positioned to dispose the first port above the second port when associated within a cooling system of a marine engine. In a particularly preferred embodiment of the present invention, the ball is less dense than water and, as a result, floats on the water which is within the cavity of the valve. The seal is responsive to an upward movement of the ball within the cavity and, in a particularly preferred embodiment of the present invention, the seal is a ball seat which is shaped to receive the ball in sealing contact in response to movement of the ball against the ball seat. When water exists within the cavity of the valve, the water causes the ball to rise because the ball is less dense than the water. As the ball rises, it moves into contact with the ball seat and provides a seal. Also, flow of water upward within the cavity toward the first port from the second port, will also cause movement of the ball in an upward direct toward the ball seat. In one embodiment of the present invention, the valve comprises a first portion and a second portion that are attached together to define the cavity which captivates the ball. In certain embodiments of the present invention, a ball rest is formed in the cavity proximate the second port in order to support the ball. The ball rest permits water to flow around the ball and through the second port when the ball is located on the ball rest at the bottom of the cavity. The cooling system of the present invention can further comprise an engine having a plurality of cooling passages, with the valve being connected in fluid communication between the pump and the cooling passages. It can also comprise a thermostat housing connected in thermal communication with the valve and with the pump. Similarly, a fuel cooler and an exhaust manifold can be incorporated as part of the cooling system, with the valve being connected in fluid communication between the pump and both the fuel cooler and the exhaust manifold. Although not a requirement in all embodiments of the present invention, it is preferable to locate the valve in the cooling system conduit between the pump and other components of the cooling system. Since the purpose of the valve of the present invention is to prevent, or at least inhibit, siphoning of water back through the pump, locating the valve closer to the pump than the heat producing components will facilitate its operation. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully and completely understood from a reading of the description of the preferred embodiment in conjunction with the drawings, in which: FIG. 1 is an exploded view of a marine engine cooling system; FIG. 2 illustrates a prior art siphon inhibiting valve; FIG. 3 and 4 show section views of the present invention under two states of operation; and FIG. 5 is a section view of FIG. 4 . DESCRIPTION OF THE PREFERRED EMBODIMENT Throughout the description of the preferred embodiment of the present invention, like components will be identified by like reference numerals. FIG. 1 is an exploded view showing the components of a marine engine cooling system. In the exploded view, various water paths are represented by various series of aligned arrows. These individual flow paths will be identified by specific reference numerals in the following description. A pump 10 draws water from an intake 12 along a flow path 14 . The water intake 12 is disposed below the surface of a body of water in which the marine propulsion system is operating. Whether the body of water is a lake or sea, the water is drawn along flow path 14 by the pump 10 and induced to flow under pressure along flow path 18 and into the cooling passages of the cooling system. As an example, the power steering cooler 19 , the fuel cooler 20 , and an engine oil cooler 22 are shown connected in fluid communication with the conduits that conduct the flow path 18 toward a thermostat housing and cover assembly 30 . From the thermostat housing 30 , the cooling water is conducted along flow path 32 to an engine water circulating pump 36 . From the engine water circulating pump 36 , water is directed along two generally parallel flow paths, 41 and 42 , into the engine 50 after passing through the cooling passages within the structure of the engine 50 , the cooling water flows, along flow path 52 , back to an inlet of the thermostat housing 30 . From the thermostat housing 30 , water flows in two parallel flow paths, 61 and 62 , to the water jackets of the exhaust manifolds, 71 and 72 . After passing through the water jackets of the manifolds, 71 and 72 , the cooling water then flows into the exhaust elbows, 77 and 78 , along flow paths 81 and 82 . From there, the water is ejected with the exhaust gases as represented by flow paths 91 and 92 . When the engine 50 is turned off and the pump 10 becomes inactive, water can drain from the pump 10 , in conduit 94 , in a direction opposite to flow path 14 . As this water in conduit 94 drains back into the body of water from which it was originally drawn, it can create a siphon effect which draws water from conduit 96 in a direction opposite to flow path 18 . As a result of this siphon effect, water can be drawn from various portions of the cooling system and away from certain heat producing components, such as the engine 50 and exhaust manifolds, 71 and 72 . This prevents the water from remaining in its intended locations to remove additional heat from the heat producing components. As described above in greater detail, the siphon effect can draw heated water back into the fuel/water heat exchanger and result in vaporization of the fuel in the heat exchanger. It should be understood that after the engine 50 is turned off, heat continues to emanate from the engine and be conducted into other various other components, particularly fuel containing and conducting components. As a result, these components experience a significant temperature rise after the engine is turned off. This temperature rise can create vapor lock problems when the operator of the marine vessel attempts to restart the engine. These vapor lock problems can be prevented if the cooling water remains within the cooling system in thermal communication with the heat producing components. A siphon inhibiting device 100 is provided in series between the pump 10 and the heat producing components. The purpose of the siphon inhibiting device 100 is to prevent the flow of water within conduit 96 , in a direction opposite flow path 18 , resulting from a siphon effect that is initiated by water draining from the pump 10 back into the body of water in a direction opposite to the flow path 14 . FIG. 2 shows a siphon inhibiting valve that is known to those skilled in the art and available in commercial quantities. The valve body 110 is provided with an inlet port 112 and an outlet port 114 . When the pump 10 is operating, water flows in the direction represented by arrow W in FIG. 2, enters the inlet port 112 , flows through the internal chamber 120 of the valve body 110 , and exits from the valve through the outlet port 114 . A spring 124 provides a force against a plunger 130 which seals a passage when the head 134 of the plunger 130 moves into sealing relation within a narrowed section 136 of the passage. Water pressure from the pump 10 , causes the flow W against the head 134 of the plunger 130 and, as a result, provides sufficient force against the plunger 130 to compress the spring 124 and allow water to flow downward in FIG. 2 serially through the inlet port 112 , the internal cavity 120 , and the outlet port 114 . When the pump 10 is deactivated as a result of the engine 50 being turned off, spring 124 moves the plunger 130 upward to prevent reverse flow in an upward direction in FIG. 2, opposite to the direction represented by arrows W. This prevents water from being drawn through conduit 96 in a direction opposite to the flow path 18 illustrated in FIG. 1 . Several disadvantages are inherent in the design shown in FIG. 2 . First, the force provided by spring 124 must be overcome by a downward force in the direction of arrow W against the head portion 134 of plunger 130 . This results in a pressure drop through the valve which, in turn, causes a measurable loss of flow through the cooling system compared to the flow that could otherwise by pumped by the pump 10 . Another deleterious result of the design shown in FIG. 2 is that water will be trapped on the inlet side of the head portion 134 when the operator wishes to drain the cooling system. Therefore, water will remain in certain conduits on the inlet side of the valve, upstream from the head portion 134 of plunger 130 . As a result, the draining procedure will be incomplete and some water will remain in the cooling system. This incomplete draining procedure can result in significant damage in the event that ambient temperatures decrease to below the freezing point of the cooling water. In addition, if the operator of the marine vessel attempts to operate the engine while a blockage exists within the cooling system, such as frozen cooling water, this blockage will prevent appropriate cooling of the engine and may cause damage. With continued reference to FIGS. 1 and 2, it will be significantly beneficial if a siphon inhibiting valve 100 could be provided without the inherent disadvantages of the valve shown in FIG. 2 . FIG. 3 shows a section view of a siphon inhibiting valve 100 made in accordance with the principles of the present invention. The valve 100 , as described above in conjunction with FIG. 1, is intended to be connected in fluid communication with a conduit 96 that is, in turn, connected between the pump 10 and a heat producing component, such as the engine 50 or the exhaust manifolds, 71 and 72 . A ball 200 is disposed within a cavity 204 of the valve 100 . The valve has a first port 211 and a second port 212 . The valve is configured to receive a stream of water into the first port 211 from the pump 10 , as described above in conjunction with FIG. 1, and past the stream of water serially through the cavity 204 and the second port 212 on its way to a heat producing component, such as the engine 50 or exhaust manifolds, 71 and 72 . A seal, such as the ball seat 220 is responsive to movement of the ball 200 within the cavity 204 . The seal is located between the first port 211 and the cavity 204 for the purpose of inhibiting water flow through the cavity 204 and through the first port 211 on its way back to the pump 10 . In operation, the valve 100 is positioned in the cooling system to dispose the first port 211 above the second port 212 . In a particularly preferred embodiment of the present invention, the ball 200 is less dense than water and the seal, which comprises the ball seat 220 , is responsive to the upward movement of the ball 200 within the cavity 204 . In other words, when the ball 200 moves into contact with the ball seat 220 , it blocks passage through the valve 100 . The valve 100 can comprise a first portion 231 and a second portion 232 which can be combined together, as shown in FIG. 3, to define the cavity 204 in which the ball 200 is captivated. FIG. 3 shows the position of the ball 200 , relative to the cavity 204 and relative to the second port 212 , when water is flowing under the influence of the pump 10 in the direction represented by arrows W. When in this position, water can flow around the ball 200 with relatively little restriction. The resulting small pressure drop is not significant and does not represent an appreciable decrease in the efficiency of the cooling system. FIG. 4 shows the valve 100 when the ball 200 is moved upward within the cavity 204 and against the ball seat 220 . The ball 200 will assume this position under two different circumstances. First, if water attempts to flow upward through the valve 100 , in the direction from the second port 212 towards the first port 211 , the flow of water will carry the ball 200 upward and into contact with the ball seat 220 . This will occur even if the ball is more dense than water. This movement will create a seal to prevent further movement of water in that same direction. Another circumstance that will cause the ball 200 to assume the position shown in FIG. 4 is the presence of non flowing water within the cavity 204 . Since, in a preferred embodiment of the present invention, the ball 200 is less dense than water, it will float on the water within the cavity 204 and be moved into position against the ball seat 220 . This position, as described above, will block further movement of water through the valve 100 in an upward direction from the second port 212 toward the first port 211 . With continued reference to FIG. 4, it should be noted that a ball rest 230 is formed in the cavity 204 proximate the second port 212 for the purpose of supporting the ball 200 when the ball moves to the position illustrated in FIG. 3 . The ball rest 230 provides a plurality of ribs 234 as illustrated in FIG. 5 which is a section view of FIG. 4, as shown. The ribs 234 support the ball 200 above the non-ribbed portion of the surface 240 surrounding the opening leading to the second port 212 . As a result, water can freely flow around the ball 200 , and between the ribs 234 , when water is flowing in the direction represented by arrows W in FIG. 3 . With reference to FIGS. 1, 3 , 4 , and 5 , it can be seen that the present invention provides a means for preventing a siphon effect from drawing water through conduit 96 in a direction opposite to flow path 18 . As described above, this siphon effect can be created when water drains from the conduit 94 in a direction opposite to the flow path 14 . The valve 100 of the present invention prevents this continuing siphon effect that can lead to significant difficulty in starting the engine 50 because of vapor lock, as described in detail above. It can also be seen that the valve 100 of the present invention performs this function in a way that does not preclude the easy draining of the water cooling system at a later time. When the operator intentionally opens drain valves to induce draining of the cooling system, water flows away from the second port 212 and out of the cavity 204 . As a result, support for the ball 200 is removed and, in addition, forces on the ball 200 in a downward direction exceeds those in a upward direction. As a result, the ball 200 falls away from the ball seat 220 and rests on the ball rest which comprises the ribs 234 . This allows a complete draining of the system, including the portion of the cooling system comprising conduit 96 and the power steering cooler 19 , if provided in this system. As a result, the valve 100 of the present invention provides the beneficial affect of preventing the siphoning of water out of the cooling system while not adversely affecting the easy draining of the system when the watercraft operator desires to do so. Although the present invention has been described in considerable detail and illustrated to show a preferred embodiment, it should be understood that alternative embodiments are also within its scope.

A siphon inhibiting valve is provided for a marine engine cooling system. The purpose of the valve is to prevent the draining of the pump and outboard drive unit from creating a siphon effect that draws water from portions of the cooling system where heat producing components exists. The valve also allows intentional draining of the system when the vessel operator desires to accomplish this function. The valve incorporates a ball that is captivated within a cavity. If the ball is lighter than water, its buoyancy assists in the operation of the valve.

This application is a divisional of U.S. patent appl. No. 09/631,503 filed Aug. 3, 2000 now U.S. Pat. No. 6,391,380. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is concerned with stiffener materials for use in the fabrication of shoes and for making other articles. 2. Description of the Related Art Stiffener materials traditionally are used in the shoe industry to provide varying degrees of resilient, stiffness, and shape-retention to the heel and toe portions of shoes. These materials have been made of either a needle punched non-woven fabric which is saturated with a latex resin composition or a flexible thermoplastic resin that is extruded or powder coated onto a woven fabric or extruded into a sheet. If a non-woven fabric is employed, the typical material which is selected is a polyester mat made from fibers having a denier of between 3 and 6 deniers or mixtures of such fibers. The latex resin compositions may be based on resins selected from styrene resins, styrene-butadiene resins, vinyl acetate resins, vinyl chloride resins or acrylic resins. The extruded thermoplastic or powder coated thermoplastic materials may be selected from the group consisting of polyvinyl chloride, ionomers, high, medium or low density polyethylene, polypropylene, polyesters, polystyrene and copolymers and compatible blends of such polymers. After the initial coating of the woven or non-woven fabrics, a separate hot melt coating operation is carried out to provide a finished stiffener which has self adhesive properties which are sufficient to bond the stiffener to an inner layer and an outer layer of a manufactured article. The powder-coated resins usually contain particles which measure from about 100 to about 590 microns which prevents the particles from passing through the woven fabrics during the coating operation. A typical non-woven latex saturated stiffener is made with a polymer latex wherein the dispersed polymer particles have an average latex particle size of less than one micron and a filler such as calcium carbonate which has an average particle size of less than 10 microns. A continuous sheet of the non-woven fabric may be passed through a bath containing the latex composition to saturate the non-woven fabric prior to passing the saturated sheet through calendaring rolls, which are spaced apart with a filer gauge, in order to remove excess latex composition. The saturated non-woven fabric is then clipped onto a tenter frame and passed to a drying oven to remove the water from the latex composition. The dried non-woven fabric is then sized by passing the dried latex saturated non-woven fabric through calendar rolls and wound on a beam. The product may be made heavier, thinner, stiffer or more flexible depending on the weight and thickness of the non-woven fabric, the amount of the latex applied and the formulation of the latex. Since the dried non-woven fabric has no adhesive properties after the application of the latex and the oven drying, it is necessary to apply a hot melt adhesive, such as a ethylene vinylacetate hot melt adhesive. This results in a product that can be heat activated to provide a finished stiffener which has self adhesive properties which are sufficient to bond the stiffener to an inner layer and an outer layer of a shoe. U.S. Pat. No. 4,717,496 describes a method of making a stiffening material with non-latex powders. The disclosure of U.S. Pat. No. 4,717,496 is incorporated by reference. SUMMARY OF THE INVENTION The present invention provides a novel process that produces a novel stiffener material which is made by adding an effective amount of a finely divided thermally activatable powder adhesive to a latex composition which is used to saturate a non-woven fabric to make a stiffener material. The process of the invention comprises a method of making a fabric based stiffener material having thermal adhesive properties on its top and bottom surfaces, said process comprising: (a) preparing a coating composition which comprises a latex forming resin and a finely divided powdered adhesive polymer; (b) contacting a non-woven fabric with the composition of step (a) to form a latex saturated non-woven fabric; (c) removing the excess latex from the non-woven fabric; and (d) drying the product of step(c). Accordingly, it is a primary object of the invention to provide a process where a treating composition comprising a latex based stiffening resin and a heat activated adhesive resin is used to saturate a non-woven fabric to form a treated fabric and thereafter drying and sizing said treated fabric to make a heat activated adhesive stiffener having adhesive properties on both sides of the stiffener material. It is also an object of the invention to provide a novel heat activated stiffener material which has adhesive material on the surface and on the interior of the stiffener material. It is also an object of the invention to eliminate the need to carry out a separate adhesive coating operation whereby an adhesive is applied as a separate manufacturing step to a stiffener which is prepared by a latex coating a non-woven fabric. It is also an object of the invention to provide a novel polyester containing latex composition which provides a stiffener having a good combination of stiffness, shape-retention, and resiliency. These and other objects and features of the invention will become apparent from a review of the following detailed description. DETAILED DESCRIPTION OF THE INVENTION While woven or non-woven fabrics may be used in the practice of the invention, it is preferred to employ a non-woven fabric that is made with fibers having a denier of about 6 to about 15 or fabrics made with a blend of such fibers. It is especially preferred to use a non-woven fabric made with fibers that are a 70/30 blend of 15 and 6 denier fibers. If fabrics are used that are made with deniers substantially different than the above described results, difficulty can arise when using the latex containing the adhesive and the polymer material. The polyester containing latex composition is prepared by taking a conventional latex of a material such a styrene butadiene, an acrylic polymer, a vinyl acetate resin, a vinyl chloride resins or other suitable latex forming polymer and adding an amount of a polyester powder which is sufficient to impart good adhesive properties to the finished stiffener material. Saturated powdered polyesters such as polycaprolactone, azelaic, adipic, sebacic and copolymers of polyethylene terephthalate and the like may be employed as substantially pure resins or in the form of commercially formulated adhesive compositions with conventional dispersants, tackifiers, stabilizers, fillers and the like. If the polyester is employed as a pure resin, conventional dispersants such as non-ionic surfactants, gums, colloids or thickening agents may be added to stabilize the latex containing the polyester. In order to provide an adhesive which adheres to the non-woven fabric without “dropping out” or in other words separating as a discrete powder on the non-woven fabric, it is preferred to grind the powdered polyester to a finely divided state which will remain dispersed on the non-woven fabric when it is applied from a dispersion in a polymeric latex. Generally an average particle size of less than 150 microns and more preferably less than 100 microns will provide good results. The “dropping out” phenomenon is usually observed when the process of the invention is practiced on a full scale commercial apparatus as compared to a laboratory scale operation. Ammonium chloride or other acid forming ingredients may be employed as a catalyst to cross-link certain polymer latex resins. It is preferred to add an effective amount of an organic cross-linking agent to the polyester containing latex to improve resilience and prevent “washing out” of the latex. Melamine-formaldehyde condensates are preferred. Suitable examples of these materials are described in U.S. Pat. No. 2,871,213 and U.S. Pat. No. 3,215,647, which are incorporated by reference. If a cross-linker is used, a total of 1.0% to 2.0% by weight may be used. Compatible fillers such as finely calcium carbonate, and the like may be employed. The novel stiffener may be evaluated to determine the adhesive bonding strength of the finished product by die cutting a piece of the stiffener to be tested and inserting the stiffener between two pieces of a non-woven lining material that is a 35% poly ester blend having a thickness of 0.029 inches. The three pieces are held together and placed into a back part heel counter molding machine with the female mold at 180° F. and the male mold at 290° F. The mold is closed and held in position for 17 seconds, The mold is opened and the laminate is placed, at room temperature, in a laminate cooling station having the desired shape of the final product. The shaped heel counter is now rigid and the stiffener is bonded to the two pieces of non-woven lining material. The adhesive test requires that the three part laminate remain bonded together when manual pressure is applied to pull the components apart. The resiliency test is based on making a thumb indent on the side of the heel counter and evaluating the degree which the indent bounces back. An acceptable bounce is when the indent bounces back immediately with a “ping-pong” sound. The latex of the invention will comprise the following formulation: latex forming polymer dry basis 15 wt % to 35 wt % dispersant 0.4 wt % to 1.0 wt % adhesive polymer 10 wt % to 21 wt % water 35 wt % to 50 wt % filler  0 wt % to 15 wt % Generally the preferred latex formulations will comprise the following formulation: latex forming polymer dry basis 29.5 wt % to 35 wt %   dispersant .7 wt % to .9 wt % adhesive polymer 15 wt % to 19 wt % water 43 wt % to 44 wt % filler  1.1 wt % to 11.8 wt %  The non-woven fabric should be saturated with an amount of the latex formulation that will result in a dry weight gain of between 300 to 1000 g/meter 2 of coated fabric and preferably between 400 to 900 g/meter 2 of based on the dry weight of the coated fabric after the coating and drying operation as compared to the dry weight of the uncoated fabric. The preferred drying conditions are a temperature of from 200 to 400° F. and preferably from 250° F. to 370° F. which are applied for a period of 5 to 15 minutes in a tenter frame equipped thermostatically controlled oven. DESCRIPTION OF THE PREFERRED EMBODIMENTS The following examples are added to illustrate the invention. They are not to be construed as limitations on the scope of the invention. EXAMPLE 1 A formulation was made by adding the ingredients in sequence using a laboratory propeller agitator: Styrene-butadiene copolymer 318.0 g (Dow 242 SBR on resin-49% solids; particle size 1750 Angstroms; Brookfield visc. #2-50 rpm = 70; Tg 45° C.)) Melamine-formaldehyde condensate cross-linker 8.0 g (cyrez 933; CAS. No. 88002-20-01) Water 68.0 g Oxazolidine surfactant 3.0 g (Alkaterge T-IV wt av mol wt 545 CAS No. 95706-86-8) Polyepsiloncaprolactone-88 micron av. dia. 67 g (Tone 767-MFI ASTM-D1238-73 1.9 at 80° C., 44 psi, g/10 min. mp. 140° C.; shore hardness 55D) Calcium carbonate 46 g (median particle dia. 6.5 μ; Omyacarb 6) Ammonium chloride 3 g Aqueous Soln. Sod. polyacrylate 14.5 g (Alcogum 296; Brookfield vis. 20 rpm, 25° C. 20,000-30,000 cs; 14.7-17.3% solids) Total mix Viscosity-Brookfield-3spindle-20 rpm-25° C. 2050 cps % polyester based on total weight of solids - 25% % polyester based on total weiqht of resin - 30% This formulation applied to a non-woven fabric, 166 g/m2, which was made from a 70/30 blend of 15 and 6 denier fibers. The fabric was provided on a continuous roll. 60″ wide which was passed through a trough to saturate the fabric prior to passing the fabric through a set of steel rolls that were 76″ wide and 9″ in diameter with an opposing hydraulic pressure of 500-600psi. After passing through the rolls, the fabric was dried in an oven 85 ft. long at a temperature of 130-200° C. and wound on a reel at a speed of 3.25 yards/minute. The product produced had good resiliency and a fair bond. EXAMPLE 2 A formulation was made by adding the ingredients in sequence using a laboratory propeller agitator: Styrene-butadiene copolymer 260.0 g (Dow 242 SBR on resin-49% solids; particle size 1750 Angstroms; Brookfield visc. #2-50 rpm = 70; Tg 45° C.)) Melamine-formaldehyde condensate cross-linker 8.0 g (cyrez 933; CAS. No. 88002-20-01) Water 75.0 g Oxazolidine surfactant 4.0 g (Alkaterge T-JV VA av mol wt 545 CAS. No. 95706-86-8) Polyepsiloncaprolactone-88 micron av. dia. 85 g (Tone 767-MFI D1238-73 1.9-80° C., 44 psi, g/10 min. mp. 140° C.; shore hardness 55D) Calcium carbonate 0 g (median particle dia. 6.5 μ; Omyacarb 6) Aqueous Soln. Sod. polyacrylate 22 g (Alcogum 296; Brookfield vis. 20 rpm, 25° C. 20,000-30,000 cPs; 14.7-17.3% solids) Ammonium chloride 4 g Total mix Viscosity-Brookfield-3spindle-20 rpm-25° C. 2100 cps % polyester based on total weight of solids 37.7% % polyester based on total weight of resin 40% This formulation applied to a non-woven fabric, 166 g/m2, which was made from a 70/30 blend of 15 and 6 denier fibers. The fabric was provided on a continuous roll. 60″ wide which was passed through a trough to saturate the fabric prior to passing the fabric through a set of steel rolls that were 76″ wide and 9″ in diameter with an opposing hydraulic pressure of 500-600psi. After passing through the rolls, the fabric was dried in an oven 85 ft. long at a temperature of 130-200° C. and wound on a reel at a speed of 3.25 yards/minute. The product produced has a very good bond and good resiliency. EXAMPLE 3 A formulation was made by adding the ingredients in sequence using a laboratory propeller agitator: Styrene-butadiene copolymer 227.0 g (Dow 242 SBR on resin-49% solids; particle size 1750 Angstroms; Brookfleld visc. #2-50 rpm = 70; Tg 45° C.)) Melamine-formaldehyde condensate cross-linker 7.0 g (cyrez 933; CAS. No. 88002-20-01) Water 92.0 g Oxazolidine surfactant 4.0 g (Alkaterge T-IV wt av mol wt 545 CAS. No. 95706-86-8) Polyepsiloncaprolactone-88 micron av. dia. 91 g (Tone 767-MFI D1238-73 1.9-80° C., 44 psi, g/10 min. mp. 140° C.; shore hardness 55D) Calcium carbonate 62 g (median particle dia. 6.5; Omyacarb 6) Aqueous Soln. Sod. polyacrylate 14 g (Alcogum 296; Brookfleld vis. 20 rpm, 25° C. 20,000-30,000 cPs; 14.7-17.3% solids) Total mix Viscosity Brookfiled-3spindle-20 rpm-25° C. 1850 cps % polyester based on total weight of solids 34.5% % polyester based on total weight of resin 45% This formulation applied to a non-woven fabric at a level of 166 g/m2. The non-woven fabric was made from a 70/30 blend of 15 and 6 denier fibers. The fabric was provided on a continuous roll. 60″ wide which was passed through a trough to saturate the fabric prior to passing the fabric through a set of steel rolls that were 76″ wide and 9″ in diameter with an opposing hydraulic pressure of 500-600psi. After passing through the rolls, the fabric was dried in an oven 85 ft. long at a temperature of 130-200° C. and wound on a reel at a speed of 3.25 yards/minute. The product produced had good resiliency and a good bond.

A process of making a fabric based stiffener material having thermal adhesive properties on its top and bottom surfaces which is based on (a) contacting a non-woven fabric with a latex forming resin and a finely divided powder adhesive polymer to form a latex saturated non-woven fabric; and (b) removing the excess latex from the non-woven fabric formed in step (a); and (c) drying the product of step (b).

FIELD OF THE INVENTION The invention relates to a method for anchoring a structure in a bed of a body of water. Furthermore, the invention relates to an underwater foundation for a structure, in particular a wind power station. DESCRIPTION OF RELATED ART Underwater foundations especially in the offshore area are required to an ever increasing extent. Such underwater foundations serve to anchor various types of structures, for example wind power stations projecting from the water or turbines arranged underwater for tidal power stations. For underwater foundations of such type it is known that drilled piles are produced. In this process a cased or uncased drilling is produced in the bed of a body of water. Subsequently, the borehole is filled with a concrete slurry which hardens to form the drilled piles. Such a method is known from EP 2 354 321 A1 for instance. However, the production of such concreted drilled piles is both time-consuming and labor-intensive. Moreover, when support tubes are used there is the problem that due to their relatively large contact surface the tubes are difficult to handle especially in the case of stronger underwater currents. In addition, drill cuttings accumulate during drilling, the disposal of which is laborious and may cause an undesired contamination of the body of water. Furthermore, it is known that for an underwater foundation driven piles are introduced by means of a pile driving apparatus into a bed of a body of water. However, the impact pulses occurring during underwater operations lead to considerable acoustic emissions which can have a significant detrimental effect on the underwater fauna. Hence, in some fields of application these pile-driving methods are undesirable or not permitted for environmental reasons. SUMMARY OF THE INVENTION The invention is based on the object to introduce an underwater foundation into a bed of a body of water efficiently and particularly gentle at the same time. A method according to the invention for anchoring a structure in a bed of a body of water comprises the method steps: introducing at least one screw anchor into the bed of the body of water, wherein a lower anchoring section is anchored in the bed of the body of water and an upper fastening section of the screw anchor projects from the bed of the body of water, arranging and fastening a base element on the fastening section of the screw anchor, wherein the base element has a holder for the structure, and arranging and fastening the structure on the holder of the base element. A first basic idea of the invention resides in the fact that one or several screw anchors are provided as anchoring elements in the bed of a body of water. These bar- or rod-shaped screw anchors have one or several screw flights on their outer circumference so that they can be screwed in an efficient way through a rotational movement into a bed of a body of water. In this process there is no, or hardly any, accumulation of excavated soil. Moreover, the relatively slim screw anchors, which generally have a diameter ranging from 5 cm to 30 cm are also relatively easy to handle underwater. Another aspect of the invention resides in the fact that the structure to be anchored is not fastened directly on the screw anchors. In fact, a base element for the foundation is arranged on the fastening section of the screw anchor projecting from the bed of the body of water. The base element has a holder which is adapted to the structure to be anchored. The base element is thus designed as an adapter link between the fastening section of the screw anchor and the bearing feet of a structure to be anchored. The base element can be fastened exclusively on the fastening sections above the bed of the body of water or preferably be placed onto the bed of the body of water and pre-tensioned by a tensioning means with respect to the bed of the body of water. For the purpose of fastening and/or bracing a thread portion can be provided on the fastening section of the screw anchor, wherein the base element is fastened in a releasable manner on the screw anchor by means of appropriate threaded nuts or screws. The fastening can also comprise a clamping effected by means of clamping wedges or another kind of locking. In this way, it is also easily possible to remove the base elements and, where appropriate, also the screw anchors through simple dismantling. A preferred embodiment of the invention resides in the fact that for a base element a plurality of screw anchors is introduced in a predetermined arrangement pattern into the bed of the body of water and that the base element is fastened on the plurality of screw anchors. According to the structure to be anchored and the required bearing forces almost any number and arrangement of screw anchors can be chosen. By preference, between 4 and 20 screw anchors are provided for each base element. The screw anchors can preferably have a length ranging between 3 m and 25 m. According to the invention, further flexibility for the underwater foundation is achieved in that several base elements are installed on the bed of the body of water. Hence, depending on the structure to be anchored one or several base elements can be provided. By preference, between 2 to 10 base elements are arranged so that the foundation load of a structure is distributed to this plurality of base elements. According to the invention a particularly stable underwater foundation results from the fact that the base elements are installed in a predetermined arrangement, wherein the structure to be anchored has a scaffold-type jacket structure with a central receiving part located in the center and bearing feet arranged thereon that are fastened on the holders of the base elements. A jacket structure is a foot or base area of the entire structure, through which a load distribution is effected to the individual base elements. In particular, the jacket structure can have 3 or 4 struts that extend from a central receiving part, more particularly a central tube, to the lower bearing feet. The bearing feet preferably have a shaft-shaped design and can be inserted into correspondingly arranged tubular holders on the base elements and fastened by suitable locking means, in particular screw connections. A further increase in strength of the underwater foundation is achieved in accordance with the invention in that before or after anchoring at least one ballast body is arranged on the base element. The ballast body can be a concrete or steel element. By increasing the load superimposed on the base element existing buoyant forces of the base element or the structure to be anchored are counteracted. This results in the screw anchors being relieved. According to the invention a particularly gentle anchoring is accomplished in that the screw anchor is screwed with a drilling device into the bed of the body of water. For this purpose the drilling device can be arranged above or below water. By means of the drilling device an axial feed force can additionally be exerted on the screw anchor. By preference, the feed force of the screw anchor is applied solely or to a substantial part by the screw flight on the exterior of the screw anchor during rotation. Depending on the bed of the body of water the required anchoring force can be applied solely by screwing the screw anchor in. For certain cases of application provision is made according to the invention for the screw anchor to be additionally anchored in the bed of the body of water by a binding agent which is injected into an outer circumferential area of the screw anchor. In particular, the binding agent can be injected by high-pressure injection through a central duct in the screw anchor via radial outlet nozzles on the anchoring section of the screw anchor into the outer circumferential area. This brings about an additional connection and an increase of the frictional forces between the screw anchor and the surrounding ground material. Furthermore, according to the invention it is preferred that a mast is provided which is inserted into the central receiving part of the jacket structure and fastened thereon. The mast can extend, in particular, from the jacket structure located underwater in the upward direction beyond the water surface. In accordance with the invention provision is furthermore made for an underwater foundation for a structure, wherein the underwater foundation has at least one screw anchor which is introduced into a bed of a body of water, wherein a lower anchoring section is anchored in the bed of the body of water and an upper fastening section of the screw anchor projects from the bed of the body of water, and at least one base element which is arranged underwater and fastened on the at least one screw anchor, wherein the base element has a holder for the structure. This underwater foundation is produced, in particular, by the method described above. As a result, the advantages outlined above are attained. Basically, the base element can be a solid body. According to the invention it is preferred that the base element is designed in a scaffold-type manner. In this manner, the base element offers a lesser contact surface especially in the case of underwater currents. For a good load distribution an upper and a lower beam plane can be provided which are connected to each other via vertical supports. Another advantageous embodiment resides in the fact that a base element has one or several holders for receiving the structure. The holders can be sleeve-shaped receiving parts or supports in particular, into which corresponding shaft-shaped bearing feet of the structure to be anchored are inserted and fastened therein. To increase the superimposed load provision is made according to the invention in that on the base element one or several supporting areas for ballast bodies are designed. In particular, the supporting areas are provided on the upper side of the base element. If the weight of the ballast bodies is sufficiently high they do not require additional fastening. However, additional provision can be made for fastening bolts or further locking or fastening means to fix the ballast bodies on the base element. The invention furthermore relates to a wind power station having a mast which is anchored into a bed of a body of water by means of the previously described underwater foundation. The wind power station comprises a mast of up to over 100 m in height, in the upper mast area of which a windmill with a generator is arranged that transforms a rotational movement of the windmill into electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS In the following the invention is described further by way of preferred embodiments illustrated schematically in the drawings, wherein show: FIG. 1 : a schematic view of screw anchors introduced in a bed of a body of water according to a first step of the invention; FIG. 2 : a perspective view of the arrangement of base elements on the bed of a body of water according to a second step pursuant to the invention; FIG. 3 : the arrangement of a structure to be anchored on the base elements according to a third step pursuant to the invention; FIG. 4 : a perspective view of a base element according to the invention; and FIG. 5 : a schematic view of an underwater foundation according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT According to FIG. 1 a plane, hence a substantially plane surface, is initially produced on a bed of a body of water 5 . In the illustrated embodiment a plurality of screw anchors 20 is screwed into this area of the bed of the body of water 5 for a total of four base elements to be provided. The rod-shaped screw anchors 20 have a lower anchoring section 22 that is provided with a single screw flight 26 of approximately disk-shaped design. By means of a drilling apparatus, not illustrated here, the screw anchors 20 are drilled in a screw-like fashion into the bed of the body of water. For each of the four base elements to be arranged a total of nine screw anchors 20 are introduced in the illustrated embodiment in a square arrangement pattern with equal distance to each other. An upper fastening section 24 , which accounts for approximately 10 to 20% of the total length of the screw anchor 20 , projects from the bed of the body of water 5 . After this first method step scaffold-type base elements 30 are lowered from a ship or pontoon, not illustrated here, by means of a crane onto the bed of the body of water 5 and are positioned on the respective fastening sections 24 of the screw anchors 20 , as can be seen from FIG. 2 . A base element 30 has a box-shaped scaffold frame 32 which is composed of H-beams. Corresponding to the arrangement pattern of the screw anchors 20 sleeve-shaped fastening means 37 are arranged. The base element 30 is positioned in such a way on the bed of the body of water 5 that the pencil-shaped fastening sections 24 of the screw anchors 20 fittingly project into the sleeve-shaped fastening means 37 . By way of locking means, in particular screw connections, that are not illustrated here, the sleeve-shaped fastening means can be firmly connected to the fastening sections 24 of the screw anchors 20 . In a center area of the base element 30 a tubular central receiving part 34 for a structure to be anchored is arranged. Furthermore, on the upper side of the base element 30 supporting areas 38 are provided, onto which a total of eight identically constructed, prism-shaped ballast bodies 40 are placed. After the base elements 30 have been arranged and fastened underwater on the bed of the body of water 5 the actual structure 10 to be anchored is lowered from the water surface and positioned in the holders 34 of the base elements 30 , as becomes apparent from FIG. 3 . In the illustrated embodiment the structure 10 is designed as a so-called jacket structure 12 which can serve as a base area for receiving a mast, for example for a wind power station. According to the number of the base elements 30 provided this jacket structure 12 comprises four shaft-shaped vertically extending bearing feet 16 which are positioned in the sleeve-shaped holders 34 of the base elements 30 and fastened therein. The bolt-shaped bearing feet 16 are connected to each other through lateral struts 17 which surround a square. Within this arrangement a sleeve-shaped central receiving part 14 is arranged in the center which is connected via four central struts 18 and four diagonal struts 19 to the lateral struts 17 and therefore the bearing feet 16 . The central receiving part 14 is provided for receiving and holding a mast. Following fastening of the jacket structure 12 , which is usually located underwater, a mast can be lowered from the water surface and a mast base can be fastened in the central receiving part 14 . According to FIG. 4 an embodiment of a base element 30 pursuant to the invention is shown in greater detail. The base element 30 has a scaffold frame 32 which essentially consists of two horizontal planes that are welded together in a lattice-type manner of horizontal beams 42 . The upper and the lower horizontal planes are welded to each other by vertical supports 44 so that a cuboid scaffold frame 32 is formed. According to the positions of the screw anchors 20 sleeve-shaped fastening means 37 extend vertically through the scaffold frame 32 . At their upper end the outer sleeve-shaped fastening means 37 merge into a total of eight diagonal supports 46 that extend from the upper horizontal plane towards the central, vertically extending holder 34 . Between the diagonal supports 46 on the upper side of the upper horizontal plane of the scaffold frame 32 supporting areas 38 are arranged, on which a total of eight prism-shaped ballast bodies 40 are arranged. The ballast bodies 40 are in particular formed of concrete and serve to secure the superimposed load. All in all, an underwater foundation 1 , illustrated schematically again in FIG. 5 , is created by the method according to the invention. In the illustrated embodiment a total of four base elements 30 are arranged on the bed of the body of water and anchored by way of nine screw anchors 20 at a time in the bed of the body of water 5 . The fastening of the base elements 30 is effected by sleeve-shaped fastening means 37 , into which the bar-shaped fastening sections 24 of the screw anchors 20 extend. On the base elements 30 a central, tubular holder 34 is arranged in each case which is connected laterally via diagonal supports 46 to the tubular fastening means 37 . The fastening means 37 located in the center of the base element 30 is connected directly to the central holder 34 . A structure 10 is placed into the four holders 34 in total, in which case a total of four bearing feet 16 fittingly project into the holders 34 and are fastened therein. The underwater foundation 1 is especially well-suited for offshore applications but can also be used in lakes, rivers or other bodies of water.

The invention relates to a method for anchoring a structure in a bed of a body of water comprising the method steps of introducing at least one screw anchor into the bed of the body of water, arranging and fastening a base element on the fastening section of the screw anchor, wherein the base element has a holder for the structure, and arranging and fastening the structure on the holder of the base element. Furthermore, the invention relates to an underwater foundation produced by this method.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to improvements in fuel conservation means and more particularly, but not by way of limitation, to a device adapted to be interposed between a carburetor and manifold of an internal combustion engine, or the like, for increasing the conservation of the fuel. 2. Description of the Prior Art In the usual internal combustion engine, or the like, the fuel-air mixture normally moves through the carburetor directly into the manifold and to the combustion chamber for burning. The fuel and air are normally admitted into the carburetor and directed simultaneously into the manifold, with certain air to fuel ratios being considered optimum for achieving an efficient burning of the fuel-air mixture. For example, fourteen parts air to one part fuel is considered to be an optimum air to fuel ratio. However, with the normal present day carburetor mechanism the air and fuel are usually not sufficiently mixed prior to discharge into the combustion chamber, thus resulting in an inefficient burning of the fuel. This causes waste of the fuel and usually causes the discharge of pollutants into the atmosphere through the engine exhaust system. With the current and ever increasing concern with the shortage of fuels, and dangers of air pollution, it is becoming urgent to reduce fuel waste and reduce the exhaust of pollutants into the atmosphere. SUMMARY OF THE INVENTION The present invention contemplates a device which is particularly designed and constructed for conserving fuel during the operation of an internal combustion engine, or the like. The novel device is adapted to be interposed between the discharge or outlet side of a carburetor and the inlet or intake side of a manifold for receiving the fuel-air flow stream therethrough. The fuel-air mixture from the carburetor initially comes into contact with a rotor means and the force of the flow stream causes the rotor to rotate for stirring the flow stream and agitating the fuel-air mixture. Sonic reed or fin means is operably connected with the rotor means for simultaneous rotation therewith, and as the flow stream passes around or through the area of the sonic blade or reed, sonic vibrations are impressed on the flow stream for acting thereon. The flow stream is then directed through a heated screen or grid means, around which a magnetic force field is established. The grid means serves to straighten out the flow path of the flow stream, and the magnetic force field affects the molecular structure of the fuel and air mixture, particularly the hydrocarbon components thereof, which apparently promotes a more efficient power conversion of the fuel and air mixture. Of course, it is preferable that the heating of the screen or grid means be of a low order to avoid any accidental flashing of the fuel-air mixture passing therethrough. In addition, it is preferable that the screen or grid means comprises a pair of substantially identical grid elements spaced apart and rotationally orientated with respect to each other for providing a grid pattern for passage of the flow stream therethrough with a minimum of air restriction, or to prevent any excessive air restriction. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional elevational view of a fuel conservation device embodying the invention. FIG. 2 is a view taken on line 2--2 of FIG. 1. FIG. 3 is a view taken on line 3--3 of FIG. 1. FIG. 4 is an enlarged plan view of a grid element such as may be utilized in the invention. FIG. 5 is a plan view of a modified fuel conservation device embodying the invention. FIG. 6 is a sectional elevational view of the embodiment depicted in FIG. 5 and illustrated as installed in a manifold. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in detail, reference character 10 generally indicates a fuel conservation device for use with internal combustion engines (not shown) or the like, and comprises an outer housing 12 having a central passageway 14 extending longitudinally therethrough. Whereas the housing 12 may be of substantially any desired construction, as shown herein the housing 12 is sectional and comprises a first sleeve member 16 having one open end 17 and outwardly extending oppositely disposed flanges 18 and 18a provided at the opposite end thereof. A second sleeve 19 is secured in substantial axial alignment with the sleeve 16 by a collar 20 and is provided with one open end 21 disposed in the proximity of the open end 17 and oppositely disposed outwardly extending flanges 22 and 22a at the opposite end thereof. The flanges 18--18a and 22--22a are provided with bores 24 and 26, respectively, with the bores 24 of the flanges 18--18a being substantially axially aligned with the bores 26 of the flanges 22--22a for a purpose as will be hereinafter set forth. An annular shoulder 28 is provided on the inner periphery of the sleeve 16 spaced from the open end 17 thereof for receiving a grid means 28 thereon. The grid means 28 is secured in position on the shoulder 28 by the collar 20 in a manner as will be hereinafter set forth. A spider member or apertured disc 30 is disposed against the uppermost end of the collar 20 as viewed in FIG. 1, and an annular shoulder 32 provided on the inner periphery of the sleeve 19 rests on the ring or disc 30 for retaining the ring in position against the collar 19. Whereas the collar 20 may be of substantially any well known construction for securing the sleeves 16 and 19 in end to end relationship, as shown herein substantially one-half the outer periphery of the collar 20 is tapered radially outwardly in a direction toward the longitudinal center thereof as shown at 34, and the remaining portion of the outer periphery of the collar 20 is tapered radially inwardly toward the end thereof as shown at 36 in FIG. 1. The inner periphery of the sleeve 16 between the shoulder 28 and the open end 17 thereof is preferably of a tapered configuration complementary to the tapered portion 34 of the collar 20 for snugly receiving the collar 20 thereagainst. In addition, the inner periphery of the sleeve 19 between the shoulder 30 and the open end 21 thereof is preferably of a tapered configuration complementary to the tapered portion 36 of the collar 20 for snugly receiving the collar 20 thereagainst. Of course, suitable bolts (not shown) may be inserted through the mutually aligned pairs of bores 24 and 26 for securing the sleeves 16 and 19 together and clamping the ring 30, collar 20 and grid means 28 therein. The spider or perforated plate 30 is provided with a central bore 38 for receiving a hub 40 therethrough. A rotor member or propeller 42 is suitably journalled in the hub 40 in any well known manner (not shown) and is provided with a shaft 44 which extends through and beyond the hub 40. A blade or reed 46 is secured to the outer end of the shaft 44 in any suitable manner for rotation simultaneously with the rotor 42. The reed or blade 46 is preferably constructed from a suitable spring steel, preferably approximately five thousandths of an inch in thickness, but not limited thereto, and the plane of the reed 46 is preferably substantially perpendicular to the longitudinal axis of the shaft 44 whereby the reed 46 is rotated in the plane of its own surface during rotation of the rotor 42. In addition, a plurality of spaced apertures 48 (FIG. 3) are provided in the reed 46, said apertures preferably being of a diametric size corresponding to the usual number "80" drill bit, but not limited thereto. Of course, the reed 46 is installed or disposed downstream of the rotor 42, as clearly shown in FIG. 1, and it is to be understood that the sonic reed 46 may be stationary, or retained against rotation, if desired. The grid means 28 preferably comprises a pair of substantially identical grid-type discs 50 preferably spaced slightly apart by suitable spacer means (not shown) in order to preclude excessive restriction to the flow stream moving therethrough. Each disc 50 comprises an annular outer ring 52 (FIG. 4) having a single strand of Ni-chrome wire 54 or the like of a suitable diametric size and following a back-and-forth pathway across the open central portion of the rints 52, with the loops or segments of the wire 54 at the turning points thereof being molded or otherwise secured to the ring 52. In addition, the portions of the wire 54 spanning the open central portion of the ring 52 are preferably substantially mutually parallel. The opposite ends of the wire 54 extend beyond the outer periphery of the rings 52 as clearly shown in FIG. 4, with one end 56 emerging from one surface of the ring 52 and the opposite end 58 emerging from the opposite surface thereof. In the assembly of the grid means 28, one of the discs 50 is disposed in axial alignment with the other of the discs 50, but with a rotational orientation between the discs 50 such that the wires 54 of one disc are substantially perpendicularly disposed with respect to the wires 54 of the other disc. The ends of the wire 54 which emerge from the common sides or surfaces thereof, or the surfaces facing one another, are connected in any well known manner, and the connected ends and free ends are suitably connected with an electrical source (not shown), such as the electrical system of an automobile wherein the internal combustion engine (not shown) with which the device 10 is to be utilized is installed. Of course, it will be apparent that the opposite ends 56 and 58 of the connected discs 50 may be connected with the electrical source, and the common wires which are connected between the discs 50 will electrically connect the discs 50 in the circuit. It is to be understood that the grid 28 may be of an ultimate substantially unitary construction in that the rings 52 of the complementary discs 50 may be cemented or otherwise secured together subsequent to the forming of the wires 54 therein whereby in essence the outer rings 52 form a single annular ring (not shown) having a pair of mutually perpendicularly arranged wire grid portions 54 in spaced relation in the central portion thereof. Whereas the housing 12 as shown herein is of a sectional construction, it is to be noted that the outer housing 12 may be of a unitary construction, having a central bore or passageway extending longitudinally therethrough wherein the rotor 42, sonic reed 46 and grid means 28 may be suitably installed. The device 10 as shown in FIGS 1, 2 and 3 is particularly designed and constructed for use in combination with a single barrel carburetor (not shown) and may be installed between the discharge side of the carburetor and the intake side of the associated manifold (not shown). The device 10 is installed in such a way that the rotor or propeller 42 is upstream from the grid means 28 with regard to the flow of the fuel-air mixture from the carburetor to the manifold. The carburetor and manifold function in the normal manner therefor, and as the fuel-air mixture is pulled into the manifold from the carburetor, the flow stream moves across the rotor 42, transmitting rotation thereto. The rotation of the rotor 42 stirs the flow stream for an agitation thereof, and as the flow stream continues to move across the sonic reed 46, sonic vibrations are impressed on the flow stream. The reed 46 may be either electrically or mechanically induced for impressing the sonic vibrations on the flow stream. The flow stream then moves across the grid means 28 wherein the path of travel of the stream is straightened and the fuel-air mixture is heated. The portion of the flow stream striking the heated wires 54 is substantially vaporized, and the remaining portion of the flow stream is heated by radiation. Also the flow stream is acted upon by the magnetic force field surrounding the wires 54. This force field apparently acts on the molecular structure of the fuel-air mixture, particularly the hydrocarbon components thereof, which results in a more efficient power conservation of the fuel-air mixture than otherwise possible. Under test conditions the increased efficiency of fuel conservation with use of the device 10 has been found to be considerable. With Dynamometer testing the results showed an increase in mileage per gallon of approximately 53.59 per cent, and an increase of two in the engine horse power. In actual road testing, the mileage per gallon was increased by 45.08 per cent. The advantages of such an increased efficiency are apparent. Referring now to FIGS. 5 and 6, a modified fuel conservation device 60 is shown which has been particularly designed and constructed for use in combination with a four barrel carburetor (not shown). The device 60 comprises a plate 62 adapted for disposition over the intake opening 64 of a suitable manifold 66 and having a plurality of apertures 68 for alignment with similar apertures or bores (not shown) provided in the manifold 66 wherein the plate 62 may be secured to the manifold 66 by suitable bolts, or the like (not shown). Of course, it is preferable to interpose a suitable gasket 67 between the plate 62 and the manifold 66. Spaced bores 70, 72, 74 and 76 are provided in the plate 62 in substantial alignment with the usual bores 78 of the manifold 66. It is preferable to provide an opening 80 between the bores 70 and 76, and a similar opening 82 between the bores 72 and 74, but not limited thereto. A fuel-air mixture handling element 84 is suspended within each manifold bore 78 from the plate 62 and since the elements 84 are substantially identical, only one will be set forth in detail herein. The element 84 comprises an annular support ring 86 suspended from the plate 62 by an arm 88. The arm 88 may be integral with the plate 62, or may be secured thereto in any suitable manner, as desired. In inwardly directed annular shoulder 90 is provided on the inner periphery of the ring 86 for receiving the grid means 28 thereagainst, and an annular groove 92 is provided in the inner periphery of the ring 86 spaced from the shoulder 90 for receiving a suitable snap ring or lock washer 94 therein for retaining the grid means 28 securely in position against the shoulder 90. A hub member 96 is spaced from the ring 86 and supported in substantial axial alignment therewith by an arm 98 which is secured to or integral with the arm 88. A rotor 100 of any suitable type is journalled in the hub 96 in any well known manner for free rotation about its longitudinal axis, and is provided with a shaft 102 which extends through and beyond the hub 96 as particularly shown in FIG. 6. The sonic reed or blade 46 is secured to the outer extremity of the shaft 102 in any suitable manner for rotation simultaneously therewith. The fuel-air mixture is pulled into the manifold 66 from the carburetor (not shown) in the usual manner, and the rotors 100 of the elements 84 are disposed directly in the flow stream of the fuel-air mixture entering the manifold. The moving flow stream transmits rotation to the rotors 100, which stir the flow stream for an agitation thereof. The flow stream then enters the area surrounding the sonic reeds 46 which impress a sonic frequency on the flow stream. The fuel-air mixture then passes through the grids 28 which heat the flow stream and magnetically affect the molecular structure of the fuel-air mixture while straightening out the flow path of the fuel-air mixture. The heated grid means 28 also substantially vaporizes the fuel-air mixture. The fuel-air mixture thus treated produces a greatly increased conservation efficiency as well as increased engine operating efficiency. It will be readily apparent that the invention may be utilized with substantially any type carburetor and manifold combination, from single barrel carburetors to multipe barrel carburetors, with great fuel conservation during operation of the associated engine, or the like. From the foregoing it will be apparent that the present invention provides a novel fuel conservation device comprising three essential and basic stages: a rotor stage wherein the fuel-air mixture flow stream is stirred for an agitation thereof, a sonic frequency stage wherein sonic frequency is impressed on the flow stream, and a heated grid stage wherein the flow stream is heated for a substantial vaporization thereof and magnetically affected as well as a straightening of the flow path of the fuel-air mixture leaving the manifold. The novel device is simple and efficient in operation and economical and durable in construction. Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.

A device adapted to be interposed between the usual carburetor and manifold of an internal combustion engine, or the like, for receiving the fuel-air mixture from the carburetor and discharging same into the manifold, said device comprising three components or stages: a rotor member, a sonic vibrator, and a heated grid means. The rotor member is mounted in the flow stream of the fuel-air mixture and is rotated by the air intake for causing oscillation of the fuel-air mixture from the carburetor. The fuel-air mixture then enters the sonic vibration stage which causes a molecular mixing of the fuel with the air. The mixed fuel-air is then passed through the heated grid or screen, which not only straightens out the path of the flow stream of the fuel-air mixture, but also promotes vaporization of the fuel-air mixture impinging the screen, and receiving the heat by radiation. A magnetic force field is established in the area of the screen or grid which magnetically affects the molecular structure of the hydrocarbon content of the fuel-air mixture to provide a more efficient power conversion of the fuel-air mixture.

[0001] This application claims the benefit of Taiwan application Serial No. 101129055, filed Aug. 10, 2012, the subject matter of which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates in general to a search method for a wireless communication system, and more particularly to a search method for finding a target location in a variable space so that an output result of a wireless communication system satisfies a target value. [0004] 2. Description of the Related Art [0005] A communication system frequently encounters optimization issues. For example, an image rejection mixer needs to adjust a size and a phase of a local signal to remove a signal of an image channel, i.e., to minimize signal energy of the image channel. In a radio-frequency identification (RFID) application, a carrier signal transmitted from a reader becomes noise due to reflection, and the noise may then be received by the reader. The energy of such noise also needs to be minimized. [0006] To achieve optimization, a most appropriate value for a controllable variable is sought for in order to render a maximized or minimized output result. The search process may be accomplished through algorithms. For example, exhaustive search is a type of algorithm that tries all possible variable combinations of a variable once. According to all output results generated by the combinations, an optimal output result can be identified, and thus the most appropriate values for the variable can be obtained. However, as each of the variable combinations needs to be executed once, the exhaustive search process for finding the most appropriate variable values is not only extremely time-consuming but also involves an immense amount of computations. Therefore, the conventional exhaustive search is impractical for a communication system that demands high-speed and power-saving features. SUMMARY OF THE INVENTION [0007] The invention is directed to a search method for a wireless communication system for finding a target location in a variable space. The variable space is constructed by a set of variables and has a plurality of sub-spaces. The target location renders an output result of the communication system to satisfy a target value. [0008] According to an aspect the present invention, a search method for finding a target space in a variable space is provided. The variable space is constructed by a set of variables and has a plurality of sub-spaces. The target space renders an output result of a wireless communication system to satisfy a target value. The search method includes steps of: providing the set of variables; identifying a target sub-space where the target location is located from the sub-spaces; obtaining a plurality of gradients of the output result at a predetermined location from the target sub-space, each of the gradients corresponding to a direction of change; and selecting one from the directions of change according to the gradients, and changing values of the set of variables along the selected direction of change to find the target location. [0009] According to another aspect of the present invention, a search method for finding a target location in a variable space is provided. The variable space is constructed by a set of variables and has a plurality of sub-spaces. The target location renders an output result of a wireless communication system to satisfy a target value. The search result includes steps of: providing two quadrature compensation signals; providing the set of variables for controlling the compensation signals; feeding the compensation signals to an input of the wireless communication system to affect the output result of the wireless communication system; identifying a target sub-space where the target location is located from the sub-spaces; obtaining a plurality of gradients of the output result at a predetermined locations, each of the gradients corresponding to a direction of change; and selecting one from the directions of change according to the gradients, and changing values of the set of variables along the selected direction of change to find the target location. [0010] The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0011] FIG. 1 shows a conventional radio-frequency identification (RFID) system. [0012] FIG. 2 depicts a structure in a reader in FIG. 1 . [0013] FIG. 3 is a block diagram of a transceiver applicable to an RFID system according to one embodiment of the present invention. [0014] FIG. 4 is a relationship diagram between phases and signal strengths of associated signals in FIG. 3 . [0015] FIG. 5 is a variable space constructed by amplification ratio control signals IGM and QGM. [0016] FIG. 6 is an exemplary optimal algorithm adopted by a digital signal controller in FIG. 3 . [0017] FIG. 7 is an example of step 112 of FIG. 6 . [0018] FIG. 8 is an example of steps 114 and 116 in FIG. 6 . [0019] FIG. 9 is an example of 138 I of FIG. 8 . DETAILED DESCRIPTION OF THE INVENTION [0020] Noise optimization for a radio-frequency identification (RFID) reader is utilized as an example in the embodiments for explaining the present invention. It should be noted that the present invention is not limited to applications of an RFID reader, but is also suitable for optimization of other applications in wireless communications. For example, based on the disclosed embodiments, a person having ordinary skill in the art may also implement the present invention for image rejection. [0021] Referring to FIG. 1 , an RFID system generally requires a reader and an RFID tag. In an RFID operation, an RF electric wave is transmitted by the reader 10 to trigger the RFID tag 12 within coverage, and an electric current is generated through electromagnetic sensing to power a chip on the RFID tag 12 and to backscatter a wireless signal to the reader 10 . [0022] The RFID tag 12 usually transmits a message via a modulated carrier signal when backscattering to the reader 10 . At this point, the reader 10 however still transmits unmodulated carrier signals for powering a passive tag. FIG. 2 shows a structure in the reader 10 . A majority of a carrier signal Cx sent by the transmitter 14 is transmitted to the environment via an antenna 18 . Due to slight impedance mismatch in real situations, a small part of the carrier signal Cx is reflected by the antenna 18 , as indicated by a reflected carrier signal CRx in FIG. 2 . The reflected carrier signal CRx and a wireless signal Rx received by the antenna 18 are jointly received by the receiver 16 via a coupler 20 . Compared to the desired wireless signal Rx, the reflected carrier signal CRx is equivalently noise that should be restrained or eliminated. The presence of the reflected carrier signal CRx lowers a signal-to-noise ratio (SNR) of a receiving terminal of the receiver 16 . Once the reflected carrier signal CRx is aggravated, the wireless signal Rx may be overwhelmed by the reflected carrier signal CRx and become unidentifiable. In an ideal approach, the reflected carrier signal CRx is totally eliminated or mitigated to be lower than a target value, so that the wireless signal Rx may remain identifiable and thus increasing the SNR. [0023] FIG. 3 shows a block diagram of an RFID transceiver. Referring to FIG. 3 , a transceiver 60 includes a reader 62 , an antenna 64 , and several discrete elements. [0024] A digital message to be transmitted by the reader 62 is converted by a digital-to-analog converter (DAC) 68 and up-converted by a mixer 70 , and is transmitted to the environment via a transmitting terminal Tx of the transmitter 66 , a power amplifier 72 , a coupler 74 and the antenna 64 . The mixer 70 mixes the modulated signal outputted by the DAC 68 and a carrier signal provided by a local oscillator. [0025] A receiver 76 includes a low-noise amplifier (LNA) 78 , a mixer 80 and an analog-to-digital converter (ADC) 84 . The wireless signal transmitted by the RFID tag and received by the antenna 64 is processed by the coupler 74 , a balanced and unbalanced converter (balun) 86 and a receiving terminal RX, and is then received by the receiver 76 . After processes of down-conversion and analog-to-digital conversion, the receiver 76 provides a corresponding digital signal to a digital signal processor 88 , which can be implemented in hardware, software or a combination thereof. For example, processor 88 may be in the form of an application specific integrated circuit (ASIC) that is encoded with logic instructions operable to perform the functions described herein. [0026] As the transmitter 66 transmits the carrier signal Cx via the transmitting terminal TX, the power amplifier 72 , a coupler 74 and the antenna 64 , a part of the carrier signal Cx is reflected by the antenna 64 as the reflected carrier signal CRx. As far as wireless signals from the RFID tag are concerned, the reflected carrier signal CRx is noise that should be restrained or eliminated. Without appropriate processing, noise such as the reflected carrier signal CRx are included in the wireless signal, and are received by the receiver 76 via the coupler 74 , the balun 86 and the receiving terminal RX. [0027] The reader 62 further includes a noise canceller 90 for eliminating or restraining the noise (i.e., the reflected carrier signal CRx) included in the wireless signal received by the receiving terminal RX to increase the SNR. The noise canceller 90 includes a quadrature basic signal generator 92 , programmable amplifiers 94 , a power detector 96 and an ADC 98 . [0028] A part of the carrier signal Cx passes through the coupler 74 and a balun 100 to reach a carrier cancelling terminal CC, and becomes a carrier cancelling signal CCx. Since the carrier cancelling signal CCx and the reflected carrier signal CRx, both being a part of the carrier signal Cx, pass through different transmission paths, the carrier cancelling signal CCx and the reflected carrier signal CRx only differ in signal phase and signal strength. FIG. 4 shows exemplary relationships between phases and signal strengths of associated signal in FIG. 3 . In FIG. 4 , assume that the carrier cancelling signal CCx is located in the fourth quadrant, and the reflected carrier signal CRx is located in the first quadrant. [0029] On basis of the carrier cancelling signal CCx, the quadrature basic signal generator 92 provides a quadrature basic signal pair (I B , Q B ). Taking FIG. 4 for example, the quadrature basic signal generator 92 generates a basic signal pair (I B , Q B ), which are respectively located at borders of the first quadrant in FIG. 4 . [0030] The two programmable amplifiers 94 linearly amplify the received basic signal pair (I B , Q B ) according to amplification ratios g I and g Q determined by amplification ratio control signals IGM and QGM, respectively, into corresponding compensation signals I CC and Q CC . The two compensation signals I CC and Q CC are consolidated into a feedback signal IQ CC , which is then fed to the input of the receiver 76 , i.e., the receiving terminal RX. The digital signal processor 88 provides amplification ratio control signals IGM and QGM for controlling the signal strength and polarity of the quadrature compensation signals I CC and Q CC . Taking FIG. 3 for example, the programmable amplifiers 94 linearly convert the basic signal pair (I B , Q B ) to the corresponding compensation signal pair (I CC , Q CC ). The feedback signal IQ CC is a vector sum of the compensation signals I CC and Q CC . The amplification ratio control signals IGM and QGM also in equivalence determine a length and an angle of the feedback signal IQ CC in FIG. 4 . Given that the feedback signal IQ CC equals a reverse of the reflected carrier signal CRx, the feedback signal IQ CC may substantially cancel out the reflected carrier signal CRx to eliminate the noises. [0031] A power detector 96 detects the signal strength of the noise in the wireless signal received by the receiving terminal RX, i.e., the strength of the reflected carrier signal CRx, to generate a received signal strength index (RSSI). According to the RSSI, the digital signal processor 88 updates the amplification ratio control signals IGM and QGM to accordingly adjust the feedback signal IQ CC . For example, the digital signal processor 88 is built in with an optimization algorithm for identifying optimal amplification ratio control signals IGM best and QGM best for rendering a lowest possible RSSI. The digital signal processor 88 records the optimal amplification ratio control signals IGM best and QGM best for normal operations, so as to eliminate the reflected carrier signal CRx and to increase the SNR at the receiving terminal RX. [0032] The amplification ratio control signals IGM and QGM are two controllable variables capable of affecting the RSSI that the digital signal controller 88 obtains. FIG. 5 shows a variable space constructed by the amplification ratio control signals IGM and QGM, with the horizontal axis representing IGM and the vertical axis representing QGM. In one embodiment of the present invention, each of the amplification ratio control signals IGM and QGM is an integer between 63 and −63. Thus, a variable space 102 is approximately a square in FIG. 5 , and the amplification ratio control signal pair (IGM, QGM) corresponds to a current location in the variable space. Further, the most appropriate amplification ratio control signal pair (IGM best , QGM best ) corresponds to an optimal location identified from the variable space 102 , such that the RSSI is a minimum value. As shown in FIG. 5 , the variable space 102 may be divided into four sub-spaces—a first quadrant I, a second quadrant II, a third quadrant III and a fourth quadrant IV. [0033] In the description below, the amplification ratio control signal pair (IGM, QGM), the most appropriate amplification ratio control signal pair (IGM best , QGM best ) and the optimal output result RSSI best are variables temporarily stored in the digital signal controller 88 . The amplification ratio control signal pair (IGM, QGM) is referred to as a current location, the most appropriate amplification ratio control signal pair (IGM best , QGM best ) is referred to as an optimal location, the RSSI (IGM, QGM) in the transceiver 60 resulted by the current location is referred to as a current output result, and the RSSI (IGM best , QGM best ) resulted by the optimal location is referred to as the optimal output result RSSI best . The optimal location and the optimal output result RSSI best are constantly modified in the process of the optimization algorithm step until the optimization algorithm step ends. [0034] FIG. 6 shows a flowchart of an optimization algorithm process employed by the digital signal controller 88 in FIG. 3 . The optimization algorithm process begins with step 110 . In step 112 , an optimal sub-space is identified from the four sub-spaces. That is, it is identified in which of the four sub-spaces the optimal location is located. In step 114 , the amplification ratio control signal pair (IGM, QGM) is modified utilizing a large step-size to coarsely determine the optimal location in the optimal sub-space. In step 116 , the amplification ratio control signal pair (IGM, QGM) is modified utilizing a small step-size to fine-tune the optimal location in a predetermined region near the optimal location. The optimization algorithm process ends with step 118 . [0035] FIG. 7 shows an example of details of step 112 . In Step 120 , as a first step upon the start of step 112 , the optimal location is predetermined as an origin in FIG. 5 , i.e., (0, 0); the optimal output result RSSI best is predetermined as a current output result, i.e., RSSI (0, 0). When it is determined in step 122 that not all of the four sub-spaces are checked, step 124 is performed to relocate the current location to a central location of a sub-space that is not yet checked. Taking the first quadrant I in FIG. 5 for example, the central location is (32, 32). When it is determined in step 126 that the current output result is not better than the optimal output result RSSI best , step 122 is performed to check another sub-space. When it is determined in step 126 that the current output result is better than the optimal output result RSSI best , step 128 is performed to update the current location and the current output result as the optimal location and the optimal output result RSSI best , respectively. The completion of step 128 is equivalently having checked all of the sub-spaces, and step 122 is iterated. Once it is determined in step 122 that all of the four sub-spaces are checked, step 129 is performed to set the optimal location as the current location, and step 130 is performed to end step 112 . [0036] Taking FIG. 5 as an example, when ending step 130 in FIG. 7 , the optimal output result RSSI best is a minimum value among RSSI (32, 32), RSSI (−32, 32), RSSI (−32, −32) and RSSI (32, −32); the optimal location is the location corresponding to the minimum value. After going through five points of (0, 0), (32, 32), (−32, 32), (−32, −32) and (32, −32), the current location returns to the identified optimal location. [0037] FIG. 8 shows an example of details of steps 114 and 116 in FIG. 6 . In step 132 , two gradients |ΔRSSI IGM | and |ΔRSSI QGM | of the current location are calculated. The gradients |ΔRSSI IGM | and |ΔRSSI QGM | respectively correspond to the horizontal axis (IGM) and the vertical axis (QGM), where ∥ represents an absolute value calculation. For example, ΔRSSI IGM =RSSI (IGM+4, QGM)−RSSI (IGM, QGM); ΔRSSI QGM =RSSI (IGM, QGM+4)−RSSI (IGM, QGM). A difference between |ΔRSSI IGM | and |ΔRSSI QGM | determines a subsequent moving direction from the current location. When it is determined in step 134 that |ΔRSSI IGM | is greater, it implies that the optimal location can be more quickly found if the amplification ratio control signal IGM is first changed. Conversely, when it is determined in step 134 that |ΔRSSI IGM | is smaller, it implies that optimal location can be more quickly found if the amplification ratio control signal QGM is first changed. In FIG. 8 , processes following step 134 at the left and right sides are substantially the same, with only a sequence of change priorities of the amplification ratio control signal IGM and the amplification ratio control signal QGM being the opposite. In the description below, details of subsequent steps when a determination result of step 134 is affirmative are given. Details of subsequent steps when the determination result of step 134 is negative can be easily deduced, and shall be omitted herein. [0038] In step 136 I, the step-size variable StepSize is set to 8. In step S 138 I, the current location is changed along the horizontal axis (IGM) in FIG. 5 using a step size of 8 to update the most appropriate amplification ratio control signal IGM best and the optimal output result RSSI best . Similarly, in step 140 I, the current location is changed along the vertical axis (QGM) in FIG. 5 using a step size of 8 to update the most appropriate amplification ratio control signal IGM best and the optimal output result RSSI best . [0039] For example, assume that the determination result of step 134 in FIG. 8 is affirmative, and the current location and the optimal location are both (32, 32) in the first quadrant. In step 138 I, the location is changed from (32, 32) towards the left or the right utilizing a step-size of 8 to search for a location that generates the minimum RSSI in the first quadrant. In step 138 I, it is possible that eight locations (0, 32), (8, 32), (16, 32) . . . (56, 32) have been searched. Assuming that among the eight locations (0, 32), (8, 32), (16, 32) . . . (56, 32), the location that generates the minimum RSSI is (8, 32). In step 138 I, the most appropriate amplification ratio control signal IGM best is updated to 8, and so the optimal location is (8, 32), and the optimal output result RSSI best is currently RSSI (8, 32). Similarly, in step 140 I, the location is changed from (8, 32) upwards or downwards utilizing a step-size of 8 to search for a location that generates the minimum RSSI in the first quadrant. Assuming that among the eight positions (8, 0), (8, 8), (8, 16) . . . (8, 56), the location that generates the minimum RSSI is (8, 16). In step 140 I, the most appropriate amplification ratio control signal QGM best is updated to 16, so that the optimal location is currently (8, 16), and the optimal output result RSSI best is currently RSSI (8, 16). From the above examples, it is concluded that the optimal location can be identified by searching through a maximum of 16 locations in steps 138 I and 140 I. Assuming that positive and negative values of the gradients of the RSSI are utilized for assisting in determining the search direction of the current location, it is probable the optimal location can be found by searching through a smaller number of locations in steps 138 I and 140 I. [0040] In step 142 I, the step-size variable StepSize is set to a smallest value of 1. In step 144 I, the current location is changed along the horizontal axis (IGM) in FIG. 5 utilizing a step-size of 1 to update the most appropriate amplification ratio control signal IGM best and the optimal output result RSSI best . Similarly, in step 146 I, the current location is changed along the vertical axis (QGM) in FIG. 5 utilizing a step-size of 1 to update the most appropriate amplification ratio control signal QGM best and the optimal output result RSSI best . Step 148 I, following step 146 I, performs the same operations as those in step 144 I. [0041] Assuming that after step 140 I in FIG. 8 , the current location and the optimal location are updated to (8, 16), and the optimal output result RSSI best is updated to RSSI (8, 16). Similar to step 136 I, in step 144 I, an optimal location that generates the minimum RSSI is searched for among 15 locations (1, 16), (2, 16) . . . (8, 16) . . . (15, 16) to fine-tune the optimal location. Assume that the optimal location that generates the minimum RSSI among the 15 locations is (10, 16). In step 144 I, the most appropriate amplification ratio control signal IGM best is updated to 10. The optimal location is currently (10, 16), and the optimal output result RSSI best is currently RSSI (10, 16). [0042] Similarly, in step 146 I, an optimal location that generates the minimum RSSI is searched for among 15 locations (10, 9), (10, 10) . . . (10, 16) . . . (10, 23). Assume that the optimal location identified in 146 I is (10, 20). Similar to step 146 I, in step 148 I, only the amplification ratio control signal IGM is changed to find the optimal location. For example, step 148 I fine-tunes the most appropriate amplification ratio control signal IGM best to 13. Thus, the optimal location is finally (13, 16), and the optimal output result RSSI best is RSSI (13, 16). [0043] FIG. 9 shows an example of details of step 138 I. Based on the descriptions associated with step 138 I, steps 140 I, 144 I, 146 I, 148 I, 138 Q, 140 Q, 144 Q, 146 Q and 148 Q are be similarly deduced, and shall be omitted herein. When entering step 138 I, the current location and the optimal location are the same. In step 160 , a change Delta (=RSSI (IGM+StepSize, QGM)−RSSI (IGM, QGM)) is calculated. In step 162 , it is determined whether the change Delta is a positive or negative value. When the change is a negative value, i.e., when a determination result of step 162 is affirmative, it means that a smaller RSSI can be expected by increasing the amplification ratio control signal IGM. In step 164 , given that the amplification ratio control signal IGM does not exceed the maximum value IGM MAX of the search range in step 138 I, StepSize for the amplification ratio control signal IGM is increased. In step 166 , it is checked whether the current output result generated by the current location is still smaller than the optimal output result RSSI best . When the current output result is smaller, i.e., when a determination result of step 166 is affirmative, the optimal output result RSSI best is updated to the current output result and the optimal location is updated to the current location in step 168 . When the current output result is not smaller, i.e., when the determination result of step 166 is negative, it means that the output result RSSI will not be decreased if the amplification ratio control signal is further increased, and so the optimal output result RSSI best is almost certain. Therefore, in continuation of the negative determination result of step 166 , the current location is restored back to the optimal location in step 170 . When the change Delta in step 162 is a positive value, it means that a smaller RSSI can be obtained if the amplification ratio control signal IGM is decreased. In step 172 , given that the amplification ratio control signal IGM is not decreased to being lower than a minimum value IGM MIN of the search range in step 138 I, StepSize of the amplification ratio control signal IGM is decreased. In step 174 , it is checked whether the current output result generated by the current location is smaller than the optimal output result RSSI best . In step 176 , the optimal output result RSSI best is updated to the current output result, and the optimal location is updated to the current location. A negative determination result of step 174 means that a valley value has been reached, and so the process continues to step 170 . [0044] According to the descriptions, in one embodiment of the present invention, the step of searching for the optimal location first determines a possible sub-space where the optimal location is located, the optimal location is identified in the sub-space utilizing a larger step-size, and the optimal location is further fine-tuned utilizing a smaller step-size. Further, in an alternative embodiment of the present invention, the process of finding the optimal location begins first along the direction of change of the largest gradient and then along the direction of change of a smaller gradient. When the conventional exhaustive search process is employed for finding the optimal location in the variable space in FIG. 5 , 127*127 locations need to be searched, resulting in a lengthy computation time and consuming immense amounts of computations and resources. With the search method according to the above embodiments of the present invention, the optimal location can be determined by searching through a smaller number of locations. As the computation amount and time are significantly reduced, the search method according to the embodiments is particularly suitable to a communication system. In an alternative embodiment of the present invention, a specific target location can be determined to render the output result to satisfy a specific value, e.g., to render the output value to be larger than a target value or to be smaller than a target value. [0045] While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.

A searching method for finding a target location in a variable space is provided. The variable space is constructed by a set of variables and has multiple sub-spaces. The target location renders an output result of a wireless communication system to satisfy a target value. The search method includes steps of: providing the set of variables; identifying a target sub-space where the target location is located from the sub-spaces; obtaining a plurality of gradients of the output result at a predetermined location from the target sub-space, each of the gradients corresponding to a direction of change; and selecting one from the directions of change according to the gradients, and changing values of the set of variables according to the selected direction of change to find the target location.

FIELD OF THE INVENTION This invention relates to magnetic closure means and carrying bags incorporating same. More particularly, this invention relates to magnetic closure and illumination means and re-closable carrying bags incorporating same. BACKGROUND OF THE INVENTION Carrying bags incorporating closure and illumination means or devices are known. For example, re-closable carrying bags have been including illumination means to light up the interior of a carrying bag to provide useful facilities to a user, for example, for searching items inside the carrying bag when in a dark environment. U.S. Pat. No. 4,912,611 describes a handbag with an actuator which closes the contact of a control switch and turn on a light source when the handbag or purse is opened. U.S. Pat. No. 5,444,605 describes a purse with an illumination device and a manual switch to turn on and off a light bulb inside the carrying bag. U.S. Pat. No. 6,120,162 describes an automatic magnetic actuation system for inner illumination of a container in which an illumination means is turned on by magnetic induction when a closure flap of the handbag is moved away from a switching device. Carrying bags equipped with means for automatic actuation of an inner illumination means when the carrying bags are opened provide security alert to a user, especially in a crowded or a dark environment when the handbag can be more easily and adversely tampered. However, known closure and illumination means for use in carrying bags are not satisfactory. For example, the illumination means of the handbag described in U.S. Pat. No. 6,120,162 require a relatively complicated circuitry with wirings distributed inside the carrying bag and with the closure parts separately mounted from the illumination switching device. Hence, it would be highly desirable if there can be provided improved closure and illumination means and carrying means incorporating same so that the carrying bags can be easily opened and closed and, at the same time, when the carrying bag is inadvertently or adversely opened, the light will be automatically lit to alert the owner. Of course, the actuated light can also help the bag owner when searching for items inside the bag. In this specification, the term “carrying bags” refers generally to portable containers including, but not limited to, containers with flexible closure means such as handbags or purses and containers with semi-rigid or substantially rigid closure parts such as suitcases, briefcases, make-up case, or pilot cases. OBJECT OF THE INVENTION Accordingly, it is an object of the present invention to provide improved closure and illumination means and carrying bags incorporating same. More specifically, although of course not solely limited thereto, it is also an object of the present invention to provide magnetic closure with inner illumination means for use in carrying bags and carrying bags incorporating the same so that the carrying bags can be more conveniently closed without much effort by the owner, and at the same time, when opened, the interior of the carrying bag will be lit so as to assist the owner as well as, or, alternatively, providing the appropriate alert. At a minimum, it is an object of the present invention to provide the public with a useful choice of magnetic closure means and carrying bags incorporating same. SUMMARY OF THE INVENTION Broadly speaking, the present invention has described a magnetic closure means including first and second detachable closure parts which respectively comprise first and second magnetic fasteners opposite, said first and second magnetic fasteners including means for guiding and aligning the closure of said detachable closure means substantially along a pre-determined path, said first and second detachable closure parts comprise mechanical actuation means adapted for turning on an illumination means when the separation between said first and second detachable closure parts exceeds a pre-determined threshold. Preferably, said mechanical actuation means comprises co-operative actuation means for co-operatively actuating said illumination means when said first and second closure parts are separated beyond a prescribed separation. According to a preferred embodiment of the present invention, there is provided a magnetic closure and illumination means comprising said co-operative actuation means including a spring urged switching device which is pressed against spring urge to turn off said illumination means when said first and second detachable closure parts are in the magnetically engaged configuration, said switching device being released by spring urge to turn on said illumination means when said first and second detachable closure parts are separated for a prescribed separation. Preferably, one of said first and second detachable closure parts including a rigid main housing, wherein one of said magnetic fasteners, a battery compartment and an electronic circuit for controlling said illumination means being housed on said main housing, the luminescent portion of said illumination means protruding from said main housing. Preferably, said illumination means including an LED. Preferably, said first and second detachable closure parts including means for mounting on to corresponding closure parts of a carrying bag. Preferably, said first and second detachable closure parts being engagable and disengagable along said pre-determined path, said illumination means including an LED with a substantially cylindrical body, the axis of said cylindrical body being substantially orthogonal to said pre-determined path. Preferably, said first and second detachable magnetic fasteners including approaching surfaces which are in close proximity when said magnetic closure means being in the magnetically engaged closed configuration, said approaching surfaces co-operate to cause the turning on and off of said illumination means. Preferably, said switching device including a spring urged push-button for turning on and off said illumination means, said push-button protrudes from one of said approaching surfaces and extending towards another approaching surface, said push button being pushed by said another to retract towards said one of said approaching surface to turn off said illumination means when said first and second closure parts come into closing engagement. Preferably, said first and second magnetic fasteners being of compatible magnetic attractive properties. Broadly speaking, this invention has described a carrying bag or portable container with magnetic closure and illumination means as described herein. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the present invention will be explained in further detail below by way of examples and with reference to the accompanying drawings, in which: FIG. 1 is a perspective view showing first and second detachable closure parts of a magnetic closure means of a first preferred embodiment of the present invention, FIG. 2 is another perspective view showing the detachable closure parts of FIG. 1 , FIG. 3 is a perspective view from one side of the magnetic closure means when the detachable closure parts have come into closing engagement, FIG. 4 is another perspective view of FIG. 3 , FIG. 5 is a perspective view showing one of the detachable closure parts in partly exploded form, FIG. 6 is a perspective view of FIG. 5 from another side, FIG. 7 is a side view of FIG. 5 , FIG. 8 is a more detailed partial exploded view of the closure means of FIG. 1 , FIGS. 9A , 9 B and 9 C are respectively the front, side and bottom views of a second magnetic fastener of the second detachable closure part, FIGS. 10A , 10 B and 10 C are respectively the front, side and bottom views of a first magnetic fastener of the first detachable closure part, FIG. 11 is a longitudinal cross-sectional view of the main housing of one of the detachable closure parts, FIG. 12 illustrates the attachment of the first and second detachable closure parts of the magnetic closure means of FIG. 1 to the corresponding re-closable surfaces of a container, FIG. 13 is an example showing the application of the magnetic closure means of the present invention to a hand-carrying bag as a convenient example, FIG. 14 is a perspective view of a magnetic closure and illumination means of a second preferred embodiment of this invention, FIG. 15 is a perspective view of the magnetic closure and illumination means of FIG. 14 from the other side, FIG. 16 is a perspective of the first detachable closure part of the closure means of FIG. 14 , FIG. 17 is a cross-sectional view of the first detachable part of FIG. 16 , FIG. 18 is a partially exploded perspective view of the first detachable part of FIG. 16 , FIG. 19 is the partially exploded view of FIG. 18 from another side, FIG. 20 shows the approaching of the first detachable closure parts of the closure means of FIG. 14 towards the second detachable closure part, and FIG. 21 is a side view of FIG. 20 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1–11 , there is shown a first preferred embodiment of a magnetic closure and illumination means 10 of the present invention. The magnetic closure and illumination means 10 includes first and second detachable closure parts for attaching respectively to the corresponding closure parts of a carrying bag, as shown in FIGS. 12 and 13 . The first 100 and the second 200 detachable closure parts include a pair of counterpart magnetic fasteners (first and second magnetic fasteners respectively) of compatible magnetic properties, for example, of opposite magnetic polarities, so that the first and the second detachable closure parts will be held in magnetic closing engagement by magnetic attractive force between the first and the second magnetic fasteners. By utilizing magnetic fasteners with guiding and aligning means, the pair of counterpart magnetic fasteners will come into closing engagement along a pre-determined path when the pair of magnetic fasteners are in mutual magnetic proximity. This self-guided and aligned closure features of the magnetic fasteners will bring the pair of detachable closure parts into closing engagement with enhanced user convenience and benefit. One of the detachable closure parts (the first detachable closure part 100 in this example) includes, in addition to a magnetic fastener, a main housing 110 on which there are provided illumination means 120 , an electronic circuit for controlling the operation of the illumination means, actuation means 130 for operation of the electronic circuit and the illumination means, and a battery compartment 140 containing a battery 141 . The main housing can be integrally molded from plastics or stamp pressed from alloys or metallic sheets. A compartment for securely receiving the magnetic fastener (the first magnetic fastener 150 in this example) is also pre-formed so that the first magnetic fastener can be installed or mounted onto the main housing for subsequent mounting onto a carrying bag. The first 150 and the second 250 magnetic fasteners include approaching surfaces which come into close contact or close proximity of each other when the first and the second detachable closure parts have come into a closing engagement. The actuation means is disposed on the main housing and adjacent the approaching or coupling surface of the first magnetic fastener so that when the second magnetic fastener comes into closing engagement with the first magnetic fastener, the actuation means will be actuated by the closing-in motion of the approaching surface of the second magnetic fastener. In this example, the actuation means includes a push-button switch 131 which is disposed adjacent to the first magnetic fastener and within the footprint or projection of the approaching surface 260 of the second magnetic fastener. In particular, the push-button switch is disposed so that, when the second magnetic fastener is magnetically coupled with the first magnetic fastener, the push button will be pushed downwards towards the main housing and to turn off the illumination means. It will be note that, in this example, the approaching surface of the second magnetic fastener has a footprint exceeding that of the first magnetic fastener so as to provide an additional area to engage with the actuation push-button. Of course, the projection or footprint of the approaching surfaces of the first and second magnetic fasteners can be equal in which case the push-button or other actuation means will be disposed within the footprint of the approaching surfaces 160 , 260 and intermediate the approaching contact surfaces so that it will be actuated or de-actuated upon magnetic engagement between the approaching surfaces. As can be seen from the Figures, the first and the second magnetic fasteners will come into magnetic engagement or coupling along a first prescribed direction which is substantially parallel to the magnetic axis of the first and second magnetic fasteners and the push-button switch is retractable also along an a axis which is substantially parallel to the first prescribed direction. In this example, the push-button switch 131 includes a spring-urged shank protruding from the front surface of the main housing (which is substantially parallel to the approaching contact surface of the first magnetic fastener), this spring urged shank will be pressed to retreat towards the main housing so as to cause the turning-off of the illumination means by using appropriate electrical connection or circuitry known to the skilled persons without loss of generality. Of course, more sophisticated electronic circuitry with timing or other purposive or utilitarian features can also be included in the circuitry. As can be seen from FIG. 6 , the main housing includes “leg” apertures to allow the engaging legs of the first magnetic fastener to pass through and in order to engage with the closure part of the container or other articles on which the first detachable closure part is to be mounted. The first magnetic fastener 150 includes a ring-magnet 151 with the front or approaching surface 152 embraced with a cover 153 of copper, aluminum, plastic or other appropriate magnetic permeable sheet materials to provide a preferred aesthetic appearance. The back side or non-approaching side of the ring-magnet is mounted with a back plate 154 made of an appropriate magnetic or ferro-magnetic material, such as stainless iron, so that the magnetic strength of the ring-magnet can be redirected through the central aperture of the ring-shaped magnet through a cylindrical head 155 or rivet protruding from the back plate towards the approaching surface of the first magnetic fastener. The magnetic body or head is a cylindrical piece also of magnetic or ferro-magnetic material connected to the back plate by, for example, riveting or stamping so that the magnetic strength emanating from the back side of the ring-magnet can be directed towards the approaching surface of the ring-magnet through the magnetic head protruding from the back plate towards the approaching surface of the first magnetic fastener. A mounting means, such as a pair of mounting legs 156 are also attached to the sub-assembly of the ring-magnet and the back plate by the riveted head or cylindrical magnetic body as more particularly shown in FIG. 10C . Referring to FIGS. 9A to 9C , the second magnetic fastener 250 comprises a counterpart magnetic fastener with magnetic properties compatible with that of the first magnetic fastener 150 described above. Specifically, the second magnetic fastener comprises a ferro-magnetic base plate 254 and a protruding head 255 of magnetic properties compatible respectively to that of the approaching surface of the ring-magnet and the magnetic head of the first magnetic fastener. For example, if the approaching surface of the ring-magnet 151 and the magnetic head 155 of the first magnetic fastener are respectively of the “N” and “S” magnetic characteristics, ferro-magnetic base plate and protruding head can both be of non-magnetized in order to be magnetically compatible with the first magnetic fastener. Alternatively, the ferro-magnetic base plate 254 and protruding head 255 can be respectively of the “S” and “N” polarities to be compatible without loss of generality. It will be appreciated that the application of a ring-shaped magnet with a magnetic head protruding from the central aperture of the ring, so that the magnetic strength from the back or non-approaching side of the ring-shaped magnet can be utilized for added coupling strength will also enhance the self-guided and self-aligned coupling between the first and the second magnetic fasteners. Instead of a ring-magnet, a pellet-shaped magnet with a ferro-magnetic brace which surrounds the rim of the pellet magnet and redirects magnetic strength from the back side to the outer-rim of the pellet magnet, as described in U.S. Pat. No. 6,378,174, can be used. The magnetic fasteners in this example include guiding and aligning means. The guiding and a ligning means is co-operatively formed between the protruding head of the second magnetic fastener and the partly retracted ferro-magnetic head in the central aperture of the ring-magnet. The appearance of the opposite magnetic polarities at the approaching surface further enhance the self-guiding and aligning. Turning now to the operation of the magnetic closure means, when the first and the second detachable closure parts are in mutual proximity, the magnetic field in their proximity will cause the first and second detachable closure parts to move towards each other and towards a closing engagement as a result of the magnetic interaction between the first and second magnetic fasteners. Although the fasteners are referred to as magnetic fasteners, it will be appreciated that it is not essential to have magnets in both the first and the second magnetic fasteners since a magnet disposed in either one of the first and second magnetic fasteners will be sufficient to cause magnetic attraction to the other magnetic fastener, provided the other magnetic fastener includes a coupling or approaching surface made of an appropriate magnetic (or ferro-magnetic) material, such as iron or stainless iron without loss of generality. The approaching surface 252 of the second magnetic fastener 250 is dimensioned with an appropriate footprint or projection so that when the first and the second magnetic fasteners have entered into closing engagement configuration, the push button will be pushed sufficiently deep by the approaching surface of the second magnetic fastener to cause turning-off of the illumination means, since the light is expected to be turned off when the handbag is closed. On the other hand, when the first and the second magnetic fasteners are being separated, the spring urged push button switch will be gradually released by spring urge and will extend from the main housing of the first detachable closure part towards the second detachable closure part. When the push button has extended for a prescribed or sufficient distance from the main housing of the first magnetic fastener, the release of the push button switch will cause the turning-on of the illumination means by actuating the electronic control circuitry housed inside the main housing. In this preferred embodiment, the illumination means 120 is a discrete LED with a focusing lens, a built-in reflector and a generally cylindrical body with the luminescent portion protruding from the side of the main housing. Specifically, the axis of the substantially cylindrical body is substantially orthogonal to the prescribed direction of relative movement between the first and the second magnetic fasteners or the magnetic axis of the ring-magnet of the first magnetic fastener. By having an LED protruding from the main housing of the first detachable closure part and along a substantially orthogonal axis from the magnetic axis, the LED will not hinder the closure of the respective re-closable parts and at the same time permitting a compact design in a substantially modular form so that the first and second detachable closure parts can be available as modules for convenient assembly without requiring complicated or clumsy wirings or distribution on the carrying bag. For example, as shown in FIG. 12 , the first and second detachable closure parts can be mounted on corresponding positions on the closure parts of a portable container 20 without requiring ancillary wiring layout and an additional LED mounting, as was required in closure and illumination means of the conventional type. Likewise, FIG. 13 shows the application of the modular first and second detachable closure parts in a hand-carrying bag 30 in which the respective closure flaps of the carrying bags are mounted with the modular first and second detachable closure parts with the LED pointing towards the bottom of the carrying bag so that the direction of the light emanating from the LED is substantially orthogonal to the direction of closure as defined by the magnetic coupling direction of the first and second magnetic fasteners. A second preferred embodiment of a magnetic closure means 40 of the present invention is shown in FIGS. 14–21 . In this preferred embodiment, instead of providing a compartment for mounting a discrete magnetic fastener, the main housing 410 includes a compartment with means for mounting a ring-shaped magnet 420 and a protruding head 412 penetrating the central aperture of the ring-shaped magnet to provide equivalent magnetic effect of that of the first magnetic fastener of the first preferred embodiment. In this application, the main housing 410 comprises a base plate 411 of a magnetic or ferro-magnetic material such as stainless iron to direct the magnetic flux from the back or non-approaching side of the ring-shaped magnet to appear inside the central aperture of the ring-shaped magnet. While the base plate is made of a ferro-magnetic material for this purpose, the top part of the main housing is made of a magnetic permeable material such as plastics, resins, copper, or polymers where appropriate. Similar to the first preferred embodiment, the protruding magnetic head 412 and the mounting legs 413 can be joined together to the back plate by riveting or other appropriate fastening means without loss of generality. While the present invention has been explained by reference to the examples or preferred embodiments described above, it will be appreciated that those are examples to assist understanding of the present invention and are not meant to be restrictive. The scope of this invention should be determined and/or inferred from the preferred embodiments described above and with reference to the Figures where appropriate or when the context requires. In particular, variations or modifications which are obvious or trivial to persons skilled in the art, as well as improvements made thereon, should be considered as falling within the scope and boundary of the present invention. Furthermore, while the present invention has been explained by reference to a carrying bag, it should be appreciated that the invention can apply, whether with or without modification, to other containers without loss of generality.

A magnetic closure device having an illumination mechanism. The device includes a first detachable closure part that has the illumination mechanism, an electronic circuit, an actuator for operation of the illumination mechanism and the electronic circuit, and a first magnetic fastener with a first approaching surface. The device also includes a second detachable closure part that has a second magnetic fastener, wherein the second magnetic fastener includes a second approaching surface that is capable of forming a magnetically engaged configuration with the first approaching surface. The actuator is disposed adjacent to the first magnetic fastener and within the footprint or projection of the second approaching surface, and is actuated by the separation between the first and second approaching surfaces.

TECHNICAL FIELD [0001] The present invention relates to the field of smelting of aluminum alloys, and in particular to an alloy refiner material for refining an aluminum alloy. BACKGROUND ART [0002] Aluminum is the most abundant metal element reserved in the earth crust, has the characteristics of small density, high plasticity, good ductility and excellent casting performance and is good in corrosion resistance due to a dense oxidiation film for surface protection. Cast aluminum alloy is prepared by adding other metal or non-metal elements on the basis of pure aluminum, not only maintaining the basic properties of the pure aluminum, but also possessing excellent comprehensive performance due to the effects of alloying and thermal treatment. Al-Si cast alloy takes Si as a major secondary element, with the Si content controlled to be 4% to 22%. Al-Si based alloy has good casting properties (such as liquidity, shrinkage percentage, thermal cracking resistance, and air tightness). A356 alloy belongs to Al-Si based alloy and is widely applied to casting of various casing parts, automobile wheels, aircraft pumps, aircraft accessories, automobile transmissions, car chassis accessories and the like due to the excellent comprehensive performance thereof. [0003] At present, A356 aluminum alloy has been often adopted in the international automobile industry to cast various wheels. A356 aluminum alloy is an Al-Si-Mg based alloy, with primary α-Al and an eutectic structure as a major structure (α-Al+eutectic Si), wherein eutectic silicon takes a coarse acicular shape, and a structure taking the coarse acicular shape will severely split a matrix and reduce the mechanical property of the alloy. Therefore, modification treatment is needed to improve the structure form thereof to further improve the mechanical property of the alloy. The present invention is intended to develop a novel modifier. Accordingly, at present, there is an urgent need of a refiner, which meets the chemical requirements of A356.2 alloy and is capable of improving the structure as well as the mechanical property of the A356.2 alloy to meet the requirement of wheel production. SUMMARY OF THE INVENTION [0004] Therefore, an object of the present invention is to provide a refiner, which meets the chemical requirements of A356.2 alloy, and is capable of improving the structure as well as the mechanical property of the A356.2 alloy to meet the requirement of wheel production. [0005] In order to achieve the object described above, the present invention provides a technical solution as follows. [0006] In one aspect of the present invention, an aluminum alloy refiner is provided, which is characterized by being an amorphous alloy comprising 40 to 60 parts of Zr, 25 to 45 parts of Cu, 1 to 15 parts of Al, 1 to 10 parts of Pd and 1 to 10 parts of Nb in terms of mass fraction. [0007] In one preferable aspect of the present invention, the aluminum alloy refiner comprises 50 parts of Zr, 35 parts of Cu, 7 parts of Al, 5 parts of Pd and 3 parts of Nb in terms of mass fraction. [0008] In one preferable aspect of the present invention, the aluminum alloy refiner is prepared through rapid cooling. [0009] In one preferable aspect of the present invention, the rapid cooling is to melt Zr, Cu, Al, Pd and Nb at the temperature of 900 to 1000° C. and the refiner is prepared by a single-roll melt spinner. [0010] In one preferable aspect of the present invention, the aluminum alloy refiner is prepared with a method including the following steps: [0011] (1) mixing pure metals of Zr, Cu, Al, Pd and Nb according to a certain proportion, pre-vacuumizing a vacuum electric arc furnace to be below 10 −3 Pa, charging an argon gas (preferably under a partial pressure of 0.02 to 0.05 MPa) for smelting, and repeatedly smelting 5 times to prepare a master alloy with even components; and [0012] (2) breaking the master alloy from the step (1) into small lumps, placing the small lumps into a quartz tube, pre-vacuumizing a single-roll melt spinner to be below 10 −3 Pa, charging the argon gas (preferably under a partial pressure of 0.05 to 0.1 MPa) to melt the master alloy in the quartz tube through induction heating, with the temperature of molten alloy of 900 to 1000° C., regulating the rotation speed of a copper roll to be 3000 to 4000 r/min, and spraying the molten alloy out to the surface of the copper roll by using the argon gas, thereby preparing an amorphous alloy ribbon. [0013] In another aspect of the present invention, a method for preparing the foregoing aluminum alloy refiner described is also provided, characterized by comprising the following steps: [0014] (1) mixing pure metals of Zr, Cu, Al, Pd and Nb according to a certain proportion, pre-vacuumizing a vacuum electric arc furnace to be below 10 −3 Pa, charging an argon gas (preferably under a partial pressure of 0.02 to 0.05 MPa) for smelting, and repeatedly smelting 5 times to prepare a master alloy with even components; and [0015] (2) breaking the master alloy from step (1) into small lumps, placing the small lumps into a quartz tube, prevacuumizing the single-roll melt spinner to be below 10 −3 Pa, charging the argon gas (preferably under a partial pressure of 0.05 to 0.1 MPa) to melt the master alloy in the quartz tube through induction heating, with the temperature of molten alloy of 900 to 1000° C., regulating the rotation speed of a copper roll to be 3000 to 4000 r/min, and spraying the molten alloy out to the surface of the copper roll by using the argon gas, thereby preparing an amorphous alloy ribbon. [0016] In other aspects of the present invention, a technical solution is also provided as follows: [0017] In one aspect of the present invention, a method for smelting an aluminum alloy is provided, characterized by comprising a step of treating the aluminum alloy with a refiner, wherein the refiner is a Zr-Cu-Al-Pd-Nb amorphous alloy, which is characterized by comprising 40 to 60 parts of Zr, 25 to 45 parts of Cu, 1 to 15 parts of Al, 1 to 10 parts of Pd and 1 to 10 parts of Nb in terms of mass fraction; preferably, the amorphous alloy comprises 50 parts of Zr, 35 parts of Cu, 7 parts of Al, 5 parts of Pd and 3 parts of Nb in terms of mass fraction. [0018] In one preferable aspect of the present invention, the Zr-Cu-Al-Pd-Nb amorphous alloy is prepared through rapid cooling; and preferably, the rapid cooling is to melt Zr, Cu, Al, Pd and Nb at the temperature of . and prepare the refiner by a single-roll melt spinner. [0019] In one preferable aspect of the present invention, the Zr-Cu-Al-Pd-Nb amorphous alloy is prepared with a method including the following steps: [0020] (1) mixing pure metals of Zr, Cu, Al, Pd and Nb according to a certain proportion, pre-vacuumizing a vacuum electric arc furnace to be below 10 −3 Pa, charging an argon gas (under a partial pressure of 0.02 to 0.05 MPa) for smelting, and repeatedly smelting 5 times to prepare a master alloy with even components; and [0021] (2) breaking the master alloy from the step (1) into small lumps, placing the small lumps into a quartz tube, pre-vacuumizing a single-roll melt spinner to be below 10 −3 Pa, charging the argon gas (under a partial pressure of 0.05 to 0.1 MPa) to melt the master alloy in the quartz tube through induction heating, with the temperature of molten alloy as 900 to 1000° C., regulating the rotation speed of a copper roll to be 3000 to 4000 r/min, and spraying the molten alloy out to the surface of the copper roll by using the argon gas, thereby preparing an amorphous alloy ribbon. [0022] In one preferable aspect of the present invention, the Zr-Cu-Al-Pd-Nb amorphous alloy is added according to 0.15 to 0.80 wt % of the weight of the aluminum alloy to be treated during refining treatment. [0023] In one preferable aspect of the present invention, the refining treatment comprises the following steps: (1) melting the aluminum alloy to be treated at 750 to 800° C. and deslagging and degassing; and (2) adding the Zr-Cu-Al-Pd-Nb amorphous alloy according to 0.15 to 0.80 wt % of the weight of the aluminum alloy to be treated, holding the heat for 5 to 120 min, and degassing. [0024] In one preferable aspect of the present invention, the melting temperature in the step (1) is 790° C., and in the step (2), the Zr-Cu-Al-Pd-Nb amorphous alloy is added according to 0.20 wt % of the weight of the aluminum alloy to be treated. [0025] In one preferable aspect of the present invention, the melting temperature in the step (1) is 790° C., and in the step (2), the Zr-Cu-Al-Pd-Nb amorphous alloy is added according to 0.60 wt % of the weight of the aluminum alloy to be treated. [0026] In one preferable aspect of the present invention, the heat is held for 5 to 120 min in the step (2), for example, the heat is held for 5, 10, 30, 45 or 60 min. [0027] In other aspects of the present invention, an aluminum alloy prepared according to the foregoing method as described is also provided. [0028] In other aspects of the present invention, an application of the foregoing aluminum alloy as described to a cast aluminum alloy wheel is also provided. [0029] In other aspects of the present invention, a technical solution is provided as follows. [0030] In one aspect of the present invention, a technological method for modification treatment of an A356 aluminum alloy by adding a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is provided, characterized by comprising the following steps: [0031] Step 1, preparing of a Zr-Cu-Al-Pd-Nb amorphous ribbon by using a single-roll melt spinner, to be specific, preparing raw materials according to 40% to 60% of Zr, 25% to 45% of Cu, 1% to 15% of Al, 1% to 10% of Pd and 1% to 10% of Nb in terms of atomic percentage, smelting the raw materials in a nonconsumable electric arc smelting furnace for smelting at first, and then placing the smolten alloy into the single-roll melt spinner to prepare the Zr-Cu-Al-Pd-Nb amorphous ribbon; [0032] Step 2, smelting and refining, to be specific, with A356 aluminum alloy (chemical components of which are as shown in Table 1) as an alloy raw material and the Zr-Cu-Al-Pd-Nb amorphous ribbon prepared in Step 1 as an intermediate alloy, placing the A356 aluminum alloy into a resistance furnace for smelting at the smelting temperature of 750 to 800° C., adding the alloy raw material at the smelting temperature, holding the heat for 30 to 50 min till the A356 alloy raw material is completely smolten, deslagging and stirring for 30 s, charging an Ar gas, N 2 or other inert gases for 3 to 30 min for degassing, holding the heat for 5 to 15 min and then deslagging; adding the Zr-Cu-Al-Pd-Nb amorphous ribbon prepared in Step 1 according to 0.2 to 0.6% of the alloy raw material in terms of weight percentage, and holding the heat for 5 to 120 min at 750 to 800° C. ; and charging an Ar gas, N 2 or other inert gases for 3 to 30 min in a heat holding process for degassing, deslagging and stirring for 3 to 5 min after the heat holding is completed, and taking out a crucible to expose in the air. [0033] Step 3, gravity casting, to be specific, deslagging when the temperature of molten aluminum is 700 to 750° C., pouring the molten aluminum into a cast iron mold preheated to 200° C., and performing air cooling naturally to form an aluminum alloy rod; [0034] Step 4, thermal treatment, to be specific, performing thermal treatment on the aluminum alloy rod in the cast iron mold, which comprises: [0035] solid solution treatment, to be specific, holding the heat for the aluminum alloy rod for 2 to 6 hours in a thermal treatment furnace at 535±5° C., after heat holding, transferring the aluminum alloy rod into hot water at 70 to 90° C. within 20 seconds for quenching treatment, and taking out the rod after maintaining the rod in the hot water for 2 to 5 min; [0036] aging treatment, to be specific, after the quenching treatment is completed, transferring the rod into the thermal treatment furnace at the temperature of 130 to 160° C., holding the heat for 3 to 12 hours, and performing air cooling. [0037] In one aspect of the present invention, an application of the A356 aluminum alloy, prepared according to the forgoing technological method for modification treatment of the A356 aluminum alloy with the Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy as described, to the manufacturing of automobile wheels is provided. [0038] In one aspect of the present invention, a technological method for modification treatment of an A356 aluminum alloy with a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is provided, which comprises the following steps: preparing a Zr-Cu-Al-Pd-Nb amorphous ribbon by using a single-roll melt spinner; with an A356 aluminum alloy as an alloy raw material and the Zr-Cu-Al-Pd-Nb amorphous ribbon as an intermediate alloy, adding the intermediate alloy according to 0.2 to 0.6% of the alloy raw material in terms of weight percentage, placing the aluminum alloy into the resistance furnace for smelting at the smelting temperature of 750 to 800° C., and holding the heat for 5 to 120 min after the intermediate alloy is added; and performing gravity casting and thermal treatment. Compared with the A356 aluminum alloy to which the intermediate alloy is not added, the A356 aluminum alloy to which the Zr-Cu-Al-Pd-Nb amorphous ribbon is added as the intermediate alloy is refined in crystal grains, more even in the dispersion of an eutectic silicon structure and has the mechanical property improved to a certain extent. [0039] With adoption of the Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy as a modifier for the A356 aluminum alloy, the refiner provided by the present invention can favorably refine crystal grains as well as improve the mechanical property of the aluminum alloy to a certain extent (as shown in FIG. 3 ). Moreover, the intermediate alloy improves the strength and plasticity of the alloy, and the refined A356 aluminum alloy is very suitable for the manufacturing of automobile wheels. BRIEF DESCRIPTION OF DRAWINGS [0040] In the following, embodiments of the present invention are illustrated in detail in combination with the drawings, wherein [0041] FIG. 1A is a diagram of an as cast metallographic structure of an A356 aluminum alloy in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added in Embodiment 1 of the present invention. [0042] FIG. 1B is a diagram of an as cast metallographic structure of an A356 aluminum alloy in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added in Embodiment 2 of the present invention. [0043] FIG. 1C is a diagram of an as cast metallographic structure of an A356 aluminum alloy in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added in Embodiment 3 of the present invention. [0044] FIG. 1D is a diagram of an as cast metallographic structure of an A356 aluminum alloy in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added in Embodiment 4 of the present invention. [0045] FIG. 1E is a diagram of an as cast metallographic structure of an A356 aluminum alloy in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added in Embodiment 5 of the present invention. [0046] FIG. 2A is a diagram of a metallographic structure of an A356 aluminum alloy, in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added, at a thermal treatment state in Embodiment 1 of the present invention. [0047] FIG. 2B is a diagram of a metallographic structure of an A356 aluminum alloy, in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added, at a thermal treatment state in Embodiment 2 of the present invention. [0048] FIG. 2C is a diagram of a metallographic structure of an A356 aluminum alloy, in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added, at a thermal treatment state in Embodiment 3 of the present invention. [0049] FIG. 2D is a diagram of a metallographic structure of an A356 aluminum alloy, in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added, at a thermal treatment state in Embodiment 4 of the present invention. [0050] FIG. 2E is a diagram of a metallographic structure of an A356 aluminum alloy, in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added, at a thermal treatment state in Embodiment 5 of the present invention. [0051] FIG. 3A is a diagram of tensile strength of an A356 aluminum alloy in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added in Embodiments 1 to 5 of the present invention. [0052] FIG. 3B is a diagram of yield strength of an A356 aluminum alloy in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added in Embodiments 1 to 5 of the present invention. [0053] FIG. 3C is a diagram of percentage of elongation of an A356 aluminum alloy in which a Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy is added in Embodiments 1 to 5 of the present invention. [0054] FIG. 4A is a DSC diagram of a Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon added in the present invention. [0055] FIG. 4B is an XRD diagram of a Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon added in the present invention. DETAILED DESCRIPTION OF THE INVENTION [0056] In the following, the present invention is described in detail through embodiments, and the embodiments are provided for the convenience of understanding instead of limiting the present invention. [0057] The present invention provides performing modification treatment on an A356 aluminum alloy with a Zr-Cu-Al-Pd-Nb amorphous ribbon as an intermediate alloy, which improves the strength and plasticity of the alloy, and the treated A356 aluminum alloy can be applied to the manufacturing of automobile wheels. [0058] Embodiment 1: Technological method for modification treatment of A356 aluminum alloy with Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy, comprising the following steps: [0059] Step 1, preparing a Zr-Cu-Al-Pd-Nb amorphous ribbon by using a single-roll melt spinner, to be specific, preparing a Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy according to 50% of Zr, 35% of Cu, 7% of Al, 5% of Pd and 3% of Nb in terms of atomic percentage, wherein a process comprises the following substeps: mixing pure metals of Zr, Cu, Al, Pd and Nb according to a certain propertion, pre-vacuumizing a vacuum electric arc furnace to be below 10 −3 Pa, charging an argon gas (under a partial pressure of 0.02 to 0.05 MPa) for smelting, and repeatedly smelting 5 times to prepare a master alloy with even components; and breaking the master alloy into small lumps, placing the small lumps into a quartz tube, pre-vacuumizing a single-roll melt spinner to be below 10 −3 Pa, charging the argon gas (under a partial pressure of 0.05 to 0.1 MPa) to melt the master alloy in the quartz tube through induction heating, with the temperature of molten alloy of 900 to 1000° C., regulating the rotation speed of a copper roll to be 3000 to 4000 r/min, and spraying the molten alloy out to the surface of the copper roll by using the argon gas, thereby preparing an amorphous alloy ribbon. FIG. 4 shows DSC and XRD diagrams of the Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon, indicating that the Zr 50 Cu 35 Al 7 Pd 5 Nb 3 intermediate alloy of the present invention is an amorphous alloy. [0060] Step 2, smelting and refining, to be specific, with the A356 aluminum alloy as an alloy raw material and the Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy prepared in Step 1 as the intermediate alloy, smelting in a resistance furnace at the smelting temperature of 790° C., adding the A356 aluminum alloy at the smelting temperature, holding the heat for 35 min till the A356 alloy raw material is completely smolten, deslagging and stirring for 30 seconds, charging an Ar gas for 3 minutes for degassing, holding the heat for 5 min and then deslagging; adding the Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy accounting for 0.2 wt % of the A356 alloy, and holding the heat for 5 min at 790° C.; and charging the Ar gas for 5 min in the heat holding process for degassing, deslagging and stirring for 3 to 5 min after the heat holding is completed, and taking out a crucible to expose in the air. [0061] Step 3, gravity casting, to be specific, deslagging when the temperature of molten aluminum is 750° C., pouring the molten aluminum into a cast iron mold preheated to 200° C., and performing air cooling naturally to form a rod; [0062] Step 4, performing T6 thermal treatment on the rod in the cast iron mold (i.e. performing aging treatment after solid solution treatment), wherein the solid solution treatment is to hold the heat for the rod in a thermal treatment furnace at 540° C. for 2 hours, and then perform quenching treatment in hot water at 80° C.; and the aging treatment is to transfer the rod into the thermal treatment furnace at the temperature of 150° C. after the quenching treatment is completed, holding the heat for 12 hours, and performing air cooling. [0063] Step 5, thermal treatment, to be specific, performing thermal treatment on the aluminum alloy rod in the cast iron mold, which comprises the following substeps: [0064] solid solution treatment, to be specific, holding the heat for the aluminum alloy rod for 2 hours in a thermal treatment furnace at 540° C., after heat holding, transferring the aluminum alloy rod into hot water at 80° C. within 20 seconds for quenching treatment, and taking out the rod after maintaining the rod in the hot water for 2 to 5 minutes; and [0065] aging treatment, to be specific, after the quenching treatment is completed, transferring the rod into the thermal treatment furnace at the temperature of 150° C., holding the heat for 12 hours, and performing air cooling. [0066] With an Olympus metallographic microscope GX51, metallographic detection is performed on a test sample obtained from Step 3, as shown in FIG. 1 ( a ) , and a test sample obtained from Step 4, as shown in FIG. 2( a ) ; and with a WDW-20 universal mechanics testing machine, a tensile mechanical property test is performed on the test samples obtained from Step 4 at the tension rate of 0.1 mm/min, as shown in FIG. 3 ( a ), ( b ) and ( c ) . [0067] Embodiment 2: Technological method for modification treatment of A356 aluminum alloy with Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy, comprising the following steps: [0068] Step 1, preparing a Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy, which is the same as that in Embodiment 1; [0069] Step 2, smelting and refining, which is different from Step 2 in Embodiment 1 only in that the heat holding time at 790° C. is changed from 5 min to 10 min after the Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy is added; [0070] Step 3, gravity casting, which is the same as that in Embodiment 1; and [0071] Step 4, performing T6 thermal treatment on the rod in a cast iron mold, which is the same as that in Embodiment 1. [0072] Metallographic detection is performed on a test sample obtained from Step 3, as shown in FIG. 1 ( b ) , and a test sample obtained from Step 4, as shown in FIG. 2( b ) ; and a tensile mechanical property test is performed on the test samples obtained from Step 4, as shown in FIG. 3 ( a ), ( b ) and ( c ) . [0073] Embodiment 3: Technological method for modification treatment of A356 aluminum alloy with Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy, comprising the following steps: [0074] Step 1, preparing a Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy, which is the same as that in Embodiment 1; [0075] Step 2, smelting and refining, which is different from Step 2 in Embodiment 1 only in that the heat holding time at 790° C. is changed from 5 min to 30 min after the Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy is added; [0076] Step 3, gravity casting, which is the same as that in Embodiment 1; and [0077] Step 4, performing T6 thermal treatment on the rod in a cast iron mold, which is the same as that in Embodiment 1. [0078] Metallographic detection is performed on a test sample obtained from Step 3 , as shown in FIG. 1 ( c ) , and a test sample obtained from Step 4, as shown in FIG. 2( c ) ; and a tensile mechanical property test is performed on the test samples obtained from Step 4, as shown in FIG. 3 ( a ), ( b ) and ( c ) . [0079] Embodiment 4: Technological method for modification treatment of A356 aluminum alloy with Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy, comprising the following steps: [0080] Step 1, preparing a Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy, which is the same as that in Embodiment 1; [0081] Step 2, smelting and refining, which is different from Step 2 in Embodiment 1 only in that the heat holding time at 790° C. is changed from 5 min to 45 min after the Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy is added; [0082] Step 3, gravity casting, which is the same as that in Embodiment 1; and [0083] Step 4, performing T6 thermal treatment on the rod in a cast iron mold, which is the same as that in Embodiment 1. [0084] Metallographic detection is performed on a test sample obtained from Step 3, as shown in FIG. 1 ( d ) , and a test sample obtained from Step 4, as shown in FIG. 2( d ) ; and a tensile mechanical property test is performed on the test samples obtained from Step 4, as shown in FIG. 3 ( a ), ( b ) and ( c ) . [0085] Embodiment 5: Technological method for modification treatment of A356 aluminum alloy with Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy, comprising the following steps: [0086] Step 1, preparing a Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy, which is the same as that in Embodiment 1; [0087] Step 2, smelting and refining, which is different from Step 2 in Embodiment 1 only in that the heat holding time at 790° C. is changed from 10 min to 60 min after the Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy is added; [0088] Step 3, gravity casting, which is the same as that in Embodiment 1; and [0089] Step 4, performing T6 thermal treatment on the rod in a cast iron mold, which is the same as that in Embodiment 1. [0090] Metallographic detection is performed on a test sample obtained from Step 3, as shown in FIG. 1 ( e ) , and a test sample obtained from Step 4, as shown in FIG. 2( e ) ; and a tensile mechanical property test is performed on the test samples obtained from Step 4, as shown in FIG. 3 ( a ), ( b ) and ( c ) . [0091] Embodiment 6: Technological method for modification treatment of A356 aluminum alloy with Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy, comprising the following steps: [0092] Step 1, preparing a Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy, which is the same as that in Embodiment 1; [0093] Step 2, smelting and refining, which is different from Step 2 in Embodiment 1 only in that the weight of the Zr 50 Cu 35 Al 7 Pd 5 Nb 3 amorphous ribbon intermediate alloy added is changed from 0.2 wt % to 0.6 wt % of the A356 aluminum alloy; [0094] Step 3, gravity casting, which is the same as that in Embodiment 1; and [0095] Step 4, performing T6 thermal treatment on the rod in a cast iron mold, which is the same as that in Embodiment 1. [0096] From Embodiments 1 to 6 and FIGS. 1, 2 and 3 , it can be seen that with the addition of the Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy, the α-Al phase is refined to a certain extent, and the mechanical properties of the modified A356 are improved to a certain extent. Based on comparison between FIG. 1 and FIG. 2 , it can be seen that an eutectic silicon phase in an eutectic structure changes from shapes of strip and clustered sphere to a shape of approximate spheres dispersed in an a-Al matrix after thermal treatment. Based on comparison among ( a ), ( b ), ( c ), ( d ) and ( e ) in FIG. 1 , it can be seen that a dendritic crystal structure in (c), i.e. Embodiment 3, is the coarsest, with primary dendritic crystals and secondary dendritic crystals higher than other structures; FIG. 3 shows that both tensile strength and yield strength of ( c ) are very low, but the percentage of elongation of the material is improved, indicating that the growth of the dendritic crystals reduces the tensile strength and yield strength of the material but increases the plasticity of the material. The general requirements of the automobile wheels for the mechanical properties of the A356 aluminum alloy are as follows: the tensile strength being Rm>220 MPa, the yield strength being Rp0.2>180 MPa, and the percentage of elongation being As>7%. Embodiments 1, 2 and 4 meet these requirements, and the mechanical properties of the alloy subjected to 5 min heat holding in Embodiment 1 are the best. As the heat holding time increases, the mechanical properties undergo a phenomenon of decrease and increase in order. However, the plasticity of the material presents the opposite tendency, that is, as the heat holding time increases, the plasticity increases and decreases in order, which is in conformity with the general law that the tensile strength increases and the plasticity decreases. [0097] The preparation method of the present invention has the following advantages: [0098] (1) with adoption of a novel amorphous intermediate alloy, the ribbon is shown as an amorphous alloy in DSC and XRD in FIG. 4 and the use of the amorphous alloy allows a more even metallographic structure of a final product; [0099] (2) the intermediate alloy added in a ribbon form dissolves quickly in molten aluminum and can be distributed in an even dispersion way after proper mechanical stirring; [0100] (3) the A356 aluminum alloy treated with the Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy have even and fine crystal grains, with alloy elements distributing in an aluminum matrix in an even dispersion way, which is beneficial to the improvement of the mechanical properties of the A356 aluminum alloy; [0101] (4) with addition of the Zr-Cu-Al-Pd-Nb amorphous ribbon intermediate alloy, the as-cast structure subjected to 30 min heat holding has the most and coarsest dendritic crystals; and [0102] (5) the mechanical properties of the alloy subjected to 5 min heat holding in Embodiment 1 are the best. As the heat holding time increases, the mechanical properties undergo a phenomenon of decrease and increase in order. However, the plasticity of the material presents the opposite tendency, that is, as the heat holding time increases, the plasticity increases and decreases in order, which is in conformity with the general law that the tensile strength increases and the plasticity decreases. [0103] At the same time, the inventors also prepare and test the Zr-Cu-Al-Pd-Nb amorphous alloy comprising the following components: [0104] (A) 40 parts of Zr, 45 parts of Cu, 1 part of Al, 10 parts of Pd and 1 part of Nb; [0105] (B) 60 parts of Zr, 25 parts of Cu, 15 parts of Al, 1 part of Pd and 10 parts of Nb; [0106] (C) 52 parts of Zr, 29 parts of Cu, 7 parts of Al, 7 parts of Pd and 3 part of Nb; and [0107] (D) 57 parts of Zr, 41 parts of Cu, 12 parts of Al, 5 parts of Pd and 1 part of Nb. [0108] Results show that for the amorphous alloys in the groups above under the conditions of Embodiment 1, [0109] (1) the tensile strengths Rm of all the aluminum alloys produced by treatment are higher than 230 MPa, with the highest Rm value (283 MPa) of the amorphous alloy from Group (B); [0110] (2) the yield strengths Rp0.2 of all the aluminum alloys produced by treatment are higher than 180 MPa, with the highest Rp value (220.1 MPa) from Group (D); and [0111] (3) the percentages of elongation As of all the aluminum alloys produced by treatment are higher than 7.0%, with the highest As value (10.625%) from Group (A). [0112] Although the present invention is illustrated through the embodiments as described above in combination with the drawings of the description, the embodiments above are intended only to illustrate the experiments of the present invention in a better way, instead of limiting the scope of implementation of the present invention. Equivalent variations and relevant modifications made according to the present invention or without departing from the experimental spirit of the present invention are within the protection scope of the invention.

The present invention provides an aluminum alloy refiner, which is characterized by being an amorphous alloy comprising 40 to 60 parts of Zr, 25 to 45 parts of Cu, 1 to 15 parts of Al, 1 to 10 parts of Pd and 1 to 10 parts of Nb in terms of mass fraction. The refiner provided by the present invention can be used to favorably refine crystal grains as well as improve the mechanical property of the aluminum alloy to a certain extent. Moreover, the intermediate alloy improves the strength and plasticity of the alloy, and a refined A356 aluminum alloy is very suitable for the manufacturing of automobile wheels.

[0001] This application is a continuation of U.S. patent application Ser. No. 12/417,246 filed Apr. 2, 2009, which claims the benefit of U.S. Provisional Applications Nos. 61/041,784, filed Apr. 2, 2008; 61/041,791, filed Apr. 2, 2008; 61/041,790, filed Apr. 2, 2008; 61/041,794, filed Apr. 2, 2008; 61/041,797, filed Apr. 2, 2008; and 61/043,571, filed Apr. 9, 2008. BACKGROUND OF THE INVENTION [0002] 1. Technical Field [0003] The present invention relates to the virtual detection, quantization and characterization of immunologically detected substances electronically in human and animal biological fluids such as whole blood, serum, plasma, urine, milk, pleural and peritoneal fluids, and semen, which detection, quantification and characterization is performed in a thin chamber on a quiescent fluid sample, said chamber having at least two parallel planar walls, at least one of which is transparent. [0004] 2. Background Information [0005] This invention relates to the improvement in the performance of all immunoassays that presently involve the physical separation of bound from free analyte by, instead, performing a virtual separation of bound and free optically detected label in a ligand assay, wherein the label is preferably a fluorescent label although any optically detectable and quantifiable label will suffice. The chambers for use in this assay and the instruments for measuring the analytes in these chambers are described in the following issued U.S. Pat. Nos. 6,929,953 issued to S. C. Wardlaw; 6,869,570 issued to S. C. Wardlaw; 6,866,823 issued to S. C. Wardlaw; and U.S. Patent Application Publication No. US 2007/0087442, to S. C. Wardlaw, published Apr. 19, 2007. [0006] Physical separation of bound from free analytes have, in the prior art, been accomplished by multiple means including but not limited to, adsorption of the free label by charcoal or talc, magnetic separation of beads containing either the bound or unbound analyte, adsorption of the bound labeled analyte by the container such as antibodies coupled to the wall of a test tube and the use of second precipitation antibodies directed against the analyte binding antibody followed by centrifugation as well as the methods described in the above noted patents and publications. [0007] Some of the types of prior art physical separation of bound target analyte assays are described in the following U.S. Pat. Nos. 5,834,217; 5,776,710; 5,759,794; 5,635,362; 5,593,848; 5,342,790; 5,460,979; 5,480,778; and 5,360,719, all issued to R. A. Levine et al. In the aforementioned patents, the separation of bound from free analyte is performed by centrifugation, or other physical methods, such as decanting, filtration, or the like. [0008] The prior art also describes a type of immunoassay, which is called a “homogeneous immunoassay”. Homogeneous immunoassays do not require the physical separation of bound from non-bound, or free, analyte. The “separation of the bound from free” is accomplished by utilizing the steric interference of an enzyme by the relatively large antibody and quantifying the colored or fluorescent products of the enzymatic action. Additional methods of homogeneous assays utilize the fluorescent quenching of fluorophores to distinguish bound from free analyte. While these methods greatly simplify the performance of immunoassays, they are generally useful only for high concentrations of analytes with low molecular weight since the large molecular weight of target analytes such as proteins (e.g., insulin), growth hormones, and the like will also interfere with the enzyme and may affect quenching. Additionally immunoassays of this homogeneous type typically do not have the high sensitivity of standard immunoassays. [0009] It would be highly desirable to provide a ligand assay of a target analyte wherein the quantification of the target analyte is a virtual one which can be performed electronically thereby having the advantages of a homogeneous immunoassay while maintaining the sensitivity of standard immunoassays, as well as the ability to have large size target analytes such as hormones like insulin, growth hormone and the like. SUMMARY OF THE INVENTION [0010] Immunoassays are used to analyze a wide range of analytes, such as hormones in blood, etc. They work by the general technique of finding a specific binder which specifically binds to the target analyte being measured. A binder is referred to herein as a ligand. Ligands are defined herein as including, but not limited to those antibodies, lectins, aptimers, or naturally occurring substances, that are operative to bind a target analyte. The sample to be measured is admixed with the ligand which is specific to the target analyte, and a labeled version of the analyte to be measured. As this mixture is incubated, the labeled and unlabeled target analyte molecules compete for binding sites on the ligand. After a suitable period, the ligand is removed by any number of ways, and the label bound to the ligand is compared to the label which is unbound and remains free in the mixture. This bound/free ratio relates to the concentration of the target analyte originally in the sample, although either the bound or free label can give the same information. The use of the ratio allows the quality control check wherein the total of bound plus free is relatively constant if the volume is constant. This quality control may also be employed in the practice of this invention. [0011] According to an aspect of the present invention, a method for assaying a biological fluid sample for a target analyte material that may be in the fluid sample is provided. The method utilizes a virtual separation of free and bound target analyte disposed within the fluid sample involving electronic scanning of the sample. The method involves placing the fluid sample in a test chamber having a predetermined and fixed height so as to produce a thin layer of the fluid sample in the chamber. At least one wall of the chamber is transparent, usually the top wall, so that the sample can be observed in the chamber. In certain cases both the top and bottom walls of the chamber are transparent. The height of the chamber (e.g., typically 1μ to 200μ) can vary according to the application at hand. For example, when anticoagulated whole blood is being analyzed, a chamber height of 6μ is advantageous because it creates a monolayer of red blood cells and interspersed plasma lacunae within the blood sample [0012] The height of the fixed structure or ligand-coated bead optimally should be no less than one tenth of that of the chamber and ideally approaching the height of the chamber. The reason for this is that if the total amount of label (e.g., fluorophore) present in the free state, surrounding the particle or structure to which the label is bound, is much greater than the amount of the lowest amount of bound label to be detected, the ability to accurately determine the amount of label bound to the bead or structure is diminished due to the influence of signal to noise ratios. Mathematically there is no limit to the height of the chamber but practical limits due to signal to noise of the detected label require a thin chamber and structures occupying at least ten percent of the volume of a cylinder drawn around the periphery of the structure and extending from the base to the tip of the chamber for optimal function. In examples where the ligand is adherent to the chamber top or bottom rather than a structure or bead, the above ratios apply, but the assay optimally should be formulated so that the cylindrical volume above the bound ligand area contains not more than ten times the lowest amount bound to the ligand area that is desired to be detected. This constraint can be diminished by making the chamber as thin as possible or by altering the stoichiometry of the reaction. [0013] The method of this invention can be used to test for drug allergies or allergen sensitivities in patients at the point of care. Drug allergies and allergen sensitivities are a common and important problem. It is expensive to the patient and society. Treating a penicillin allergic patient with a penicillin class drug, for example, can cause death or serious reactions. Penicillin is used in this discussion as a representative drug and because it is the drug type that is the most common cause of severe allergic reactions. The present invention is not limited to testing for penicillin allergies, and can be used to test for sensitivity to other drugs (e.g., antibiotics, muscle relaxants, anesthetics, etc.) and allergens. [0014] Penicillin is an inexpensive, effective and generally non-toxic drug. Patients who think they have a penicillin allergy, can be treated with another less microbial-targeted drug in view of the perceived allergy. Such replacement drugs may cause serious side effects in patients, however, and incur enormous costs to the health care system, since newer medications can be hundreds or thousands of times more expensive then penicillin drugs. Equally importantly are the costs to society associated with the increased development of drug resistant bacteria, viruses, or other infectious agents that occurs when broader spectrum drugs are used instead of drugs more focused on the target organism. It is, therefore, important to individual patients, healthcare providers, and society, to determine the presence or absence of drug allergies or allergen sensitivities by methods in addition to the history given by the patient. One goal of this invention is to detect the presence or absence of drug allergies and/or allegen sensitivities in a sample of a patient's whole blood or plasma. [0015] It is well documented that many patients who claim to be allergic to penicillin are not allergic and similarly some patients who think that they are not allergic may have developed an allergy since their last exposure. There are many reports that about 80% of individuals who believe they are allergic to penicillin will in fact tolerate penicillin use, so for these patients the constraints on antibiotic choice, potentially resulting in less effective, more toxic and more expensive treatment, are unnecessary. [0016] Nowhere is the need for the ability to detect drug allergy more needed than at point of care encounters with the patient. Physicians about to prescribe a medication in their office, the emergency room or hospital do not have the luxury of waiting many hours or a day for the test to be performed either in vitro, or by skin tests. Skin testing may additionally expose the patient to risk of reaction to the testing substance and has the theoretical possibility of inducing allergy or increasing it by an anamnestic response. In vitro tests at present are complex, time consuming to perform and yield information to the physician long after it would be most useful. Additionally the allergenic nature of many drugs, including penicillin type drugs, may be due to more than one epitope and accurate testing would require testing for all common epitopes which may be the cause of the allergic response. RAST testing, well described in the literature, is generally performed on a limited number of test allergens and their epitopes. [0017] It is generally agreed that IgE mediated immune response is the cause of most severe allergic reaction including anaphylaxis, hives, intestinal swelling with diarrhea and respiratory obstruction due to swelling of airways. It is suggested by some experts that other immunoglobulin classes may also contribute to the allergic response to drugs but generally the allergic response to IgG and IgM mediated drug allergies is not life threatening and more likely to be a rash. [0018] An advantage of the present invention is that it provides a means to perform, optimally at the point of care, a determination of the presence of IgE or any other immunoglobulin which has an affinity for one or more drugs that are or may be indicated for use in a given situation. [0019] The label of choice is the use of a fluorophore that is easily detected and attached to the ligand. The present invention is not limited to using fluorometric labels, however. More than one color fluorophore may be used if it is desired to check for the presence or absence of more than one class of immunoglobulin that may become attached to the beads in the same chamber. Beads without the attached antigen are used as controls. The control beads can be chemically and geometrically similar to the coated beads, differing only in color or other means enabling their detection (e.g., fluorescence or combinations of fluorescence dyes incorporated into their structure). The control beads provide a control so that the detection, for example of significant fluorescent signal from the fluorescent labeled antibody directed against the IgE that is attached to the beads containing a determinant (epitope) of the drug being tested as a potential allergen, may be compared to the signal that is present of similar beads not coated or bound to the epitope. Thus, nonspecific binding is controlled and will not result in a false positive. DESCRIPTION OF THE DRAWINGS [0020] FIG. 1 is a schematic side view of a ligand-bearing surface which may be used to perform an immunoassay on a blood or other sample in accordance with the prior art. [0021] FIG. 1( a ) is a view similar to FIG. 1 but showing the surface after the sample has been washed away therefrom in accordance with the prior art. [0022] FIG. 2 is a schematic side view similar to FIG. 1 , but showing a ligand-bearing surface which may be used to perform a sandwich immunoassay on a blood or other sample in accordance with the prior art. [0023] FIG. 2( a ) is a view similar to FIG. 2 but showing the sample after a second label has been added to the sample in accordance with the prior art. [0024] FIG. 2( b ) is a view similar to FIG. 2( a ) but showing the surface after the sample has been washed away therefrom in accordance with the prior art. [0025] FIG. 3 is a plan view of a first embodiment of a sampling chamber formed in accordance with this invention which contains an anticoagulated whole blood sample to which blood sample ligand-bearing analyte-capturing particles have been added. [0026] FIG. 4 is a side sectional view of a portion of the sampling chamber of FIG. 3 which contains one of the ligand-coated target analyte-capturing particles. [0027] FIG. 5 is a plan view of a test chamber like that shown in FIG. 4 , showing an area of the sample containing one of the ligand-coated target analyte-capturing particles and also showing another area of the sample which does not contain one of the ligand-coated target analyte-capturing particles but only contains the free labeled target analyte in the blood sample. [0028] FIG. 6 is a fragmented cross-sectional view of a partially ligand coated target analyte capturing surface wherein portions of the surface are coated with ligands and other portions of the surface are not. [0029] FIG. 7 is a sectional schematic view of a closed chamber having a top surface such as that shown in FIG. 6 . [0030] FIG. 8 is a plan view of the surface shown in FIG. 6 . [0031] FIG. 9 is a trace of the emissions from the ligand bands on the capture surface shown in FIGS. 6 and 8 . DETAILED DESCRIPTION OF THE INVENTION [0032] Referring now to the drawings, FIGS. 1 and 1( a ) illustrate a prior art competitive immunoassay (also referred to as an “equilibrium assay”) which is commonly used for analytes of low molecular weight, such as the thyroid hormone, thyroxin, where the numeral 1 denotes a surface to which a ligand 2 , which is specific to the target analyte, is attached by any number of means well-known to the art. Surface 1 may be a transparent wall of a glass or plastic tube or a particle. A solution 3 contains a mixture of the unlabeled target analyte 4 (the unknown) and a labeled target analyte 5 . After a period of time, which may be from minutes to hours, depending upon the target and the label, the labeled target analyte 5 and the unlabeled target analyte 4 will be in an equilibrium with each other, wherein many, but generally not all, of the ligand sites 2 will be occupied with either a labeled target analyte 5 or unlabeled target analyte 4 . At this point ( FIG. 1 a ), the mixture 3 is separated from the ligand-bearing surface 1 in a manner that preserves the labeled target analytes 5 which are bound to the ligand 2 . The labeled target analytes 5 bound to the surface 1 are then measured (see FIG. 1 a ), and the free labeled target analytes may also be measured or may be calculated as: Total=Free+Bound, or Bound=Total−Free. The bound to free target analyte ratio is inversely related to the total target analyte amount in the sample. [0033] FIG. 2-FIG . 2 ( b ) show a ligand assay often referred to as a “sandwich” assay, where two separate ligands are utilized. Surface 1 has ligand 2 bound (“bound ligand”) thereto in a similar manner described above, and the sample containing the target analyte 4 is introduced into the solution 3 and incubated with the surface 1 . Either immediately, or after a suitable period of time, a separate labeled ligand 6 is introduced into the solution, which labeled ligand 6 binds to a site on the target analyte 4 which is different than bound ligand 2 ( FIG. 2 a ). This, in effect, creates a “sandwich”, containing the target analyte 4 in the center. The free labeled ligand 6 is then washed off the surface 1 to leave the surface 1 covered with labeled sites ( FIG. 2 b ). The labeled target analytes 4 bound to the surface 1 are then quantified, and the signal therefore is directly proportional to the amount of the target analyte 4 in the original sample. It is generally recognized that the sandwich assay is more precise and somewhat more accurate, but it can only be applied to target analyte molecules which have at least two different sites to which ligands can be bound. [0034] In either of the above assays, the separation of the bound label from the free label is recognized as one of the challenging aspects of the procedure, and often requires one or more mechanically complex steps, such as centrifuging, decanting, washing, etc. As a result, instrumentation to automate these tests has been relatively complex, requiring multiple operations. [0035] Aspects of the present invention, in contrast, provide a means of “virtual separation”, wherein the bound and free label are not physically separated, but rather separated by a combination of test cell configuration and mathematical manipulation of the signals from different regions in the test cell. As a result, simplified automated ligand assay methods and apparatus can be performed. [0036] According to aspects of the present invention, immunoassays or ligand assays are performed where the binder is a ligand or other a substance having a high affinity for the target analyte. [0037] Assays according to the present invention can be performed, for example, using the sample containers and imaging instrument systems described in the U.S. Patent Publication Nos. 2007/0243117 and 2007/0087442 and U.S. Pat. No. 6,866,823, all of which are hereby incorporated by reference in their entirety. The present assays are not limited to these chambers and imaging devices, however. [0038] The term “immunoassay” as used in this disclosure and claims shall mean both antibody-based binding agents and non antibody-based binding agents. Examples of the latter include, but are not limited to, intrinsic factors for binding vitamin B12, and avidin for binding biotin-labeled targets or vice versa. [0039] Under aspects of the present invention, a well-defined and physically circumscribed surface is provided to which the ligand is attached, and then the signal from the label bound to that surface is mathematically distinguished from that of any surrounding free label that may reside in solution. There are two general cases which are described as follows. [0040] FIG. 3 is a plan view of a section of a specimen chamber assembly 40 , which chamber assembly 40 contains an anticoagulated whole blood sample. The chamber assembly 40 includes upper and lower walls 7 (see FIG. 4 ), at least one of which is transparent. Preferably, both of the walls 7 are transparent. The chamber assembly 40 includes spacer members 42 (see FIG. 3 ) which are randomly located inside of the chamber assembly 40 . The spacer members 42 are preferably spherical and determine and control the height of the chamber assembly 40 . In the case of assaying an anticoagulated whole blood sample, spacer members 42 having a diameter of about 6μ work particularly well. The blood sample which is contained in the chamber assembly 40 will include individual red blood cells 44 and agglomerations of red blood cells 46 . The blood sample also includes clear plasma lacunae areas 48 which do not contain any formed blood components. Finally, the blood sample also includes a plurality of ligand-coated target analyte-capturing particles 8 which are preferably in the form of spheres. The target analyte-capturing particles 8 are randomly distributed throughout the blood sample, and may be about 3μ-4μ in diameter for a blood sample analysis, so that they can be easily detected in the blood sample. [0041] FIG. 4 shows the structure of the chamber assembly 40 of FIG. 3 . The chamber assembly 40 is bounded by top and bottom wall 7 , at least one of which must be transparent. Within the chamber is a particle 8 , whose surface is covered with a ligand 9 . The particle 8 may be any shape as long as its volume can be determined, but it is preferably a sphere. The particle 8 may be of any material to which a ligand can be attached, such as glass, polystyrene, or the like. The particles are not limited to any particular diameter (e.g., 2μ-100μ), and the diameter can vary depending on the fluid being assayed and the height of the chamber being used. The distance between the walls 7 is typically not less than the diameter of the particle 8 , but the upper distance limit will depend upon the nature of the particle 8 . [0042] A mixture 10 contains both a target analyte 11 and a labeled target analyte 12 in a manner similar to that described in connection with FIG. 1 above. After a suitable period of incubation, the signals from the bound and free target analyte are processed. [0043] FIG. 5 is a top view of a test chamber assembly like that shown in FIG. 4 , showing an undefined expanse 13 of the mixture 10 . Within this expanse, the total signal from the label 12 is collected over a defined area 14 , which area is not limited to any particular shape. The means of collection can be a fluorescence scanner, in the case of a fluorescent label, or a radio nucleotide scanner, in the case of a radio label. The area is chosen so that it includes at least one particle 8 , with a known or measurable diameter. An adjacent defined area 16 , not containing a particle, is also measured. The signal from area 16 represents that from the unbound label, since there are no binding sites in that location. The signal from area 14 , however, has a signal from both the bound and the free label. The influences of each can be determined in a number of ways. If the particle is spherical, which is a preferred shape, its volume (Vp) can be calculated from its diameter, which can be measured with the same optical system that collects the signal from the label. The volume of the defined areas 14 (V 14 ) and 16 (V 16 ) can be readily calculated from their width and the chamber depth. Assuming that the chamber volumes associated with defined areas 14 and 16 are identical, the signal from the free label is equal to that of the signal from area 16 (S 16 ). This means, that in the absence of signal from the particle (the bound label), the signal from area 14 (Sf) should be: Sf=S 16 ×(V 14 −Vp). Any signal in excess of this amount is from the bound label (Sb): Sb=S 14 −Sf. If the volume of the particle is de minimus compared to the volume within the area 14 , then the volume correction is not necessary. What is determined is the average label signal intensity per pixel (or collective group of pixels) of the scans. The term pixel as used in this application may include the meaning of one or more adjacent pixels. [0044] In a second, and most preferred embodiment, ligands are attached to at least one surface of the chamber itself. FIG. 6 shows an (upper) transparent chamber surface 17 , which may be glass or plastic, such as acrylic or polystyrene, to which a uniform coating of the ligands has been attached by any number of means well known to the art. After the uniform coating is formed, ligand are selectively removed from one or more regions 18 , either by mechanical or chemical means, or by laser ablation, consequently leaving active ligands in adjacent regions 19 . [0045] FIG. 7 shows this surface 17 as part of a thin chamber containing mixture 20 , comprising unlabeled target analyte 21 and labeled analyte 22 . The chamber is preferably less than about 1 mm in height, and is most preferably less than 200μ (e.g., in a range of 1 to 200μ). As before, after a suitable period of time, the labeled and unlabeled analyte will reach equilibrium with the ligand, leaving a portion of the labeled analyte 23 bound to the surface, but only in the region where the ligand remains. In the case of a fluorescent label, the chamber surface 17 is illuminated with light source 24 of the appropriate wavelength to excite fluorescence in the label. Lens 25 collects the fluorescent emissions, which are filtered by optical filter 26 and projected onto an image dissection device 27 , which may be a charge couple device (CCD), complimentary metal oxide semiconductor (CMOS), or the like. Alternatively, the light source may be a laser which focuses a tiny, moving spot onto the chamber, and the light collecting device 27 would be, in that case, a simple phototube or photomultiplier. [0046] The net result of either process is shown in FIG. 8 , which is a schematic top view of the chamber 28 , where the active ligand 29 and ablated ligand 30 appear as a series of vertical stripes. The scan lines from the apparatus of FIG. 7 are represented by the lines a-a. FIG. 9 is a representation of the waveform taken across the scan lines a-a, where the peaks 31 are the signal from the active ligand, and the valleys 32 are from the inactive areas. Thus, the bound label concentration is represented by the distance from the peaks to the valleys, and the height of the valleys represents the free label. The active areas and inactive areas are not limited to any particular geometry. [0047] In some embodiments, a chamber wall 17 can be used that is sufficiently flexible that it can be locally elastically deformed by subjecting it to a relatively small point load. The elastic nature of the chamber wall 17 allows a unique option to capture very weak “bound” signals. If the chamber wall 17 is compressed, such as by a small stylus just out of the imaged area, the free label 22 is expelled laterally from the local field of view, and thus its signal is markedly reduced. With this “background” signal reduced, very weak signals from bound label 23 can be detected. [0048] Multiple analytes could be measured simultaneously if the labels fluoresce at different wavelengths, or if the ligand for analyte 1 were at a different physical location in the chamber from the ligand for analyte 2 . [0049] An example of a method according to the present invention method includes performing an assay to determine whether a patient may be allergic to one or more drugs (e.g., antibiotics, including penicillin, etc.) or allergens. The assay is performed using a cartridge that has an analysis chamber containing a large number (e.g., thousands) of antibiotic epitope coated beads and uncoated control beads. For those analyses directed toward more than one antibiotic epitope, each particular antibiotic epitope is matched with a particular type of bead for identification purposes. The groups of beads associated with different epitopes can be distinguished from one another using characteristics such as a bead color, size, shape, etc; e.g., epitope A is coated on white beads, epitope B is coated by red beads, etc. A small amount of sample (e.g., 0.5 to 5 micro liters) of capillary or venous anticoagulated whole blood is deposited in the chamber (e.g., drawn into the chamber by capillary action) and upon closing the chamber the blood is directed into an area within the chamber containing the beads. After incubation for a first period of time (e.g., minutes to an hour) immunoglobulin present within the sample binds to those beads coated with a drug (or allergen) to which the immunoglobulin molecule has a specific affinity. Different immunoglobulin molecules present within the sample may have different affinities specific to different drugs (or allergens). The combined beads and blood sample is further mixed with one or more labeled antibodies directed against the immunoglobulin being tested (e.g., Immunoglobulin E (“IgE”), etc.) and allowed to incubate for a second period of time (e.g., seconds to minutes). A fluorophore may be tagged to the antibodies directed against the immunoglobulin being tested to create the “labeled antibody”. The sample is then directed into the analysis chamber of the type described above. The actual times needed for incubation for the two steps can be empirically determined and will likely depend upon the avidity and concentration of the antibodies present. The sample disposed within the chamber is analyzed by collecting the signal from the labeled antibodies both free and bound in one or more of the manners described above. If the assay involves the determination of allergy susceptibility of more than one drug, or sensitivity to more than on allergen, the analysis will include distinguishing the bound labeled antibodies as a function of the different types of coated beads as well. The bound label represents those labeled antibodies that are bound to the immunoglobulin being tested, which immunoglobulin is bound to the particle coated with the drug (or allergen) with which the particular immunoglobulin particle has a specific affinity. The amount of label bound on a particle may be calculated by measuring the total signal of the imaged particle and subtracting the surrounding free signal in the immediate area surrounding the particle that is included in the image. Ratios of the amount of label on a given class of coated beads can be calculated by measuring labeled coated and uncoated beads of the same type. Thus, the determination of whether a sample contains immunoglobulin molecules having an affinity for a given drug (or allergen) can be performed by practicing the present invention. In addition, simultaneous detection of an allergy to more than one drug (or sensitivity to more than one allergen) can be performed under the present invention using different types of detectable beads or particles, with each type coated with a different drug (or allergen). A single type particle (or bead) may be used as a control particle for all the drug allergy (allergen sensitivity) tests if the particle is the same in size and composition as the coated particles. If necessary, more than one type of control particle may be used with the size of the control particle matching the size of the drug or allergen coated particles to which it is being compared. [0050] In some embodiments, after the second incubation (the one containing the labeled ligand) the method includes the step of adding a liquid containing no label to the sample containing unbound label disposed within the chamber, thereby leaving primarily the label attached to the immobilized beads or structures. The virtual separation of bound from free is subsequently performed as previously stated but the removal of the liquid containing the label can serve to increase sensitivity of the assay at the expense of complexity. Since the total capacity of the chamber and the amount of liquid in the chamber is in the range of less than one to several micro liters, the addition of a label-free fluid to the chamber in a substantial volume (e.g., tens of micro liters) will remove much of the fluid containing label and the remaining free label signal will be removed by the utilization of the virtual separation of bound from free process. [0051] The above described methodology provides a novel and desirable technique for determining the amount of bound and free labeled target analyte within areas of a chamber that contain ligands or are free of ligands specific to that target analyte within a sample, and thereby provides qualitative and quantitative information relative to the sample. In some instances, qualitative information such as knowing whether the target analyte is present or absent in the sample is sufficient information for the analysis at hand. An example of such an instance is the determination of whether a specimen has specific IgE directed against a given drug, when the absence of such IgE is the normal state. If more quantitative information is desired (e.g., the concentration of the target analyte in the sample), the obtained bound/free information may be used with a standard curve, which curve is empirically derived for the particular target analyte and sample being considered, to determine the quantitative information; e.g., the amount of target analyte within the sample. Standard curves operable to be used with all types of immunoassays are known and the present invention is not limited to any particular standard curve. Sample curves may be performed prior to or concurrently with the assay and the results stored on the instrument performing the analysis. [0052] Although the invention has been shown and described with respect to specific detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and the scope of the invention.

Detection and characterization of immunologically detected substances are performed electronically on human and animal biological fluids such as whole blood, serum, plasma, urine, milk, pleural and peritoneal fluids, and semen, which fluids are contained in a thin chamber forming a quiescent fluid sample, which chamber has at least two parallel planar walls, at least one of which is transparent.

FIELD OF THE INVENTION The present invention relates to an ionisation vacuum gauge. More particularly, the present invention relates to an ionisation vacuum gauge for measuring the residual pressure of a gaseous material remaining in a container, for instance, after operation of a vacuum pump, the gauge being of the kind comprising an electron-emitting cathode, a grid for accelerating the electrons emitted by the cathode and a plate collecting the ionised positive molecules of the gas, wherein the measurement of the plate current by a galvanometer allows for determining the value of the residual pressure inside the container. BACKGROUND OF THE INVENTION Two kinds of vacuum gauges are known: thermionic emission vacuum gauges (also called hot cathode vacuum gauges), and field emission (or cold cathode) vacuum gauges. In thermionic emission vacuum gauges, the electron source comprises in one or more filaments, for instance of tungsten, brought to incandescence. A typical example of hot cathode vacuum gauge is the Bayard-Alpert vacuum gauge. That kind of vacuum gauge comprises a wire-shaped ion collecting plate, a cylindrical grid surrounding the plate and an incandescent tungsten filament for electron emission, located outside the grid. The electrons emitted by the filament and accelerated by the grid ionise the residual gas, and the ions and/or the ionised positive molecules are collected by the plate, which is kept at lower potential than the electron source and the grid. In the disclosed design, the electrons pass several times through the grid and, during such “in” and “out” movement, they ionise the residual gas until they hit the grid and are absorbed by it. A plate, which is designed as a simple wire allows for pressure measurements as low as about 10 −9 Pa. Indeed, because of the reduced plate wire surface, the background current is minimised due to photoelectric effect from the plate (electron emission) caused by X-rays produced by electrons hitting the grid. The example of vacuum gauge is disclosed for instance in U.S. Pat. No. 2,605,431 “Ionisation Vacuum Gauge”. The major drawback of that kind of vacuum gauges is related to the nature of the electron-emitting cathode. Actually, a heated filament is an isotropic electron source, where directionality of the electron beam is an essential parameter for vacuum gauge sensitivity. The vacuum gauge sensitivity is not constant, since the distribution of the electron emission changes direction as the temperature along the emitting cathode filament changes, this filament typically reaching temperatures up to about 2000° C. Moreover, the phenomenon of electron emission by thermionic effect entails high power consumption, long response times and a non-negligible pollution of the surrounding environment due to the release of impurities. It is the main object of the present invention to overcome the above drawbacks, by providing a miniaturised vacuum gauge, which has a great sensitivity and which does not appreciably perturb the pressure measurements. The above and other objects are achieved by a vacuum gauge as claimed in the appended claims. Advantageously, the gauge according to the invention exploits the nanotube technology for making the electron-emitting cathode. According to such a solution, electron emission takes place by field effect, and not by thermionic effect: application to a nanotube film of a strong electric field, whose flow lines are concentrated at the ends of the nanotubes, results in electron emission. A nanotube cathode is a so-called “cold” electron source, requiring very low power consumption and having high directionality. According to a preferred embodiment of the invention, due to the use of such a cathode, it is possible to utilize not only cylindrical geometry of the conventional Bayard-Alpert vacuum gauge but to use different geometries, allowing miniaturising the ionisation vacuum gauge. More particularly, according to some embodiments of the invention, the electrons continue moving in the space between the grid and the plate, without any appreciable electron amount passing again through the grid. The preferred embodiments of vacuum gauge according to the invention, given by the way of non-limiting examples, is disclosed in greater detail hereinafter, with reference to the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematical perspective representation of a nanotube; FIG. 2A is a schematical representation of a assembling nanotubes for manufacturing a nanotube film for electron emission; FIG. 2B is another schematical representation of assembling nanotubes for manufacturing a nanotube film for electron emission; FIGS. 3 to 8 are schematical perspective views of different embodiments of the invention. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1 , reference numeral 1 denotes a single-wall carbon nanotube. Carbon nanotubes are one of the possible forms of crystalline carbon, together with graphite, diamond and fullerenes. Generally, a single-wall carbon nanotube 1 can be considered as a carbon tube made of a graphite layer rolled up into a cylinder, closed at its ends by two hemispherical caps 1 b . The nanotube body is formed only by hexagonal carbon structures 3 a , where the end caps are generally formed by both hexagonal structures 3 a and pentagonal structures 3 b of carbon atoms. The diameter of a nanotube is generally in a range 0.8 to 10 nm and usually is smaller than 2 nm. The length of a nanotube is generally of the order of 10 4 to 10 5 nm, so that nanotubes can be considered monodimensional structures. Multiple nanotubes assembled into a thin film exhibit optimum field emission capability, i. e. capability of emitting electrons due to the action of a strong electric field, whose flow lines are concentrated at ends 1 b of the nanotubes. In order to exhibit good field emission capability, the nanotubes in the thin film must be arranged in ordered manner. FIGS. 2A and 2B show two typical modalities for assembling the nanotubes. In FIG. 2A , a plurality of nanotubes 5 , 5 ′, 5 ″ are arranged inside one another, so that they are concentric and form a so-called multiple-wall nanotube. In FIG. 2B , on the contrary, a plurality of nanotubes 7 , 7 ′, 7 ″ are arranged parallel and adjacent to one another, so that they form an ordered bundle. By using either arrangement described above, a nanotube film with optimum electron emission properties can be obtained. Turning now to FIG. 3 , a vacuum gauge according to the invention is shown. The ionisation vacuum gauge is of the so-called Bayard-Alpert type, which uses a cathode 31 capable of emitting electrons and formed by a nanotube film 29 arranged on a substrate 27 . The vacuum gauge is housed inside a vacuum chamber 10 and it comprises, a nanotube cathode 31 for electron emission, an anode 13 in a shape of a cylindrical grid, capable of accelerating the electrons emitted by the cathode, and a wire-shaped plate or collecting electrode 15 , located centrally of anode 13 , for collecting the gas ions and ionised positive molecules. Cathode 31 , formed by the thin nanotube film 29 arranged on the substrate 27 according to the arrangement shown in either FIG. 2A or FIG. 2B , is a low-temperature, highly directional, field-emission electron source. An extraction grid 30 is located opposite to film 29 , at short distance therefrom, and is connected to a power supply 17 keeping the grid at a potential V 30 higher than that of the substrate 27 , which is grounded. The potential difference between the substrate 27 and the extraction grid 30 generates an electric field, in which nanotube film 29 is immersed and which causes field-effect electron emission by the nanotubes. The electrons emitted by the cathode 31 are accelerated by grid-shaped anode 13 , connected to a second power supply 19 and kept at a potential V 13 >V 30 . The electrons accelerated in this manner pass through the grid 13 and move towards collecting electrode 15 that, however, being grounded, repels the electrons, causing them to pass again through grid 13 . This motion in and out of the grid 13 continues until the electrons are absorbed by the grid itself. During this motion, the electrons ionise the molecules or atoms of the residual gas contained in vacuum chamber 10 , so that the ionised molecules or atoms are attracted by the plate 15 . The ion current generated on said plate 15 can be measured by means of a galvanometer 21 . Suitable signal processing means 23 allows for obtaining the residual gas pressure inside chamber 10 from the value of the ion current, once the current intensity of the electron source of cathode 31 is known. It is clear that using a nanotube cathode allows for solving many problems inherent in the use of ionisation vacuum gauges. The nanotubes are highly directional electron sources, whereas the conventional heated filament is a substantially isotropic source. Moreover, the power required to apply to the cathode a potential difference sufficient to cause field emission by the nanotubes is far lower than that required to bring the filament to incandescence. Referring to FIG. 4 , there is shown a second embodiment of the vacuum gauge according to the invention. A chamber 10 encloses the volume containing a residual gas, the pressure of which is to be measured. The vacuum gauge substantially comprises: a cathode 31 capable of emitting electrons, which cathode is formed by a nanotube film 29 arranged on a substrate 27 and is provided with an extraction grid 30 ; a grid-shaped anode 33 , capable of accelerating the electrons emitted by cathode 31 ; and a plate or collecting electrode 35 , which is to collect the ions produced by the electron collisions with the gas atoms or molecules. In that embodiment, anode 33 is made as a substantially plane grid placed opposite to said cathode 31 , at a short distance therefrom. Thus, the electrons emitted by cathode 31 are focussed into a beam oriented according to a preferential initial direction (denoted by arrow F), substantially perpendicular to the plane of the grid 33 . It is therefore advantageous to make plate 35 as a plane plate, in register with and substantially parallel to the grid 33 . Note that, in the embodiment shown, cathode 31 and plate 35 are made as plane plates. Such members could however have a different shape as well, e.g. a concave or convex shape. Moreover, plate 35 could be also made as a small bar or a wire. The plane plate shape is however preferable since increasing the plate surface directed towards the electron source results in increasing the sensitivity of the plate. The electrons, once the cathode 31 due to field effect emits them, are accelerated through holes 34 of grid 33 in a direction perpendicular to the grid, towards plate 35 . To this end, like in the previously disclosed embodiment, the grid 33 is suitably biased at a potential V 33 higher than potential V 30 at which extraction grid 30 of cathode 31 is set and such that the electrons passing through grid 33 come out therefrom with a kinetic energy preferably in a range 100 to 150 eV, that is, in the most favourable energy range for ionisation of residual gas present in chamber 10 . In order to keep extraction grid 30 of cathode 31 and anode 33 at different potentials, two d.c. power supplies 17 , 19 connected in series are provided. Extraction grid 30 is connected to power supply 17 , which keeps the grid at a potential V 30 higher than that of grounded substrate 27 of nanotube film 29 . The electrons emitted by the cathode 31 are accelerated by grid-shaped anode 33 , connected to the second power supply 19 and kept at a potential V 33 >V 30 . During their motion between said grid 33 and said plate 35 , the electrons collide with the atoms or the molecules of the residual gas, ionising them. When arriving close to the plate 35 , the electrons are repelled by the plate, since the plate is grounded. The electrons are also repelled by the walls of chamber 10 , which also are grounded, and are directed again towards grid 33 , by which they are eventually absorbed after further collisions with the atoms or the molecules of the residual gas. The ions of the residual gas are on the contrary collected by plate 35 , which is connected with a galvanometer 21 for measuring the absorbed ion current. Suitable means 23 for processing the analogue signal generated by galvanometer 21 allows for obtaining the residual gas pressure in chamber 10 from the value of the ion current, once the current intensity of the source consisting in cathode 31 is known. To obtain a more accurate measurement, also grid 33 can be connected to a second galvanometer (not shown), for measuring the grid electron current due to the electrons absorbed by said grid. Residual pressure P x can thus be obtained according to relation: p x =c·i p /i g , where: c is a constant typical of the apparatus and of the gas nature; i p is the plate current intensity; i g is the grid current intensity. Note that using a plane geometry allows for placing the collecting plate at a greater distance from the grid (which, on the contrary, surrounds said plate in the Bayard-Alpert vacuum gauge), thus limiting the background current due to the photoelectric effect of the plate caused by X rays produced on the grid. Consequently, in the vacuum gauge according to the invention, the plate does not need to be reduced to a wire (as in the Bayard-Alpert vacuum gauge), but its surface can be advantageously increased so as to enhance the measurement sensitivity. Moreover, using the plane geometry for grid-shaped anode 33 , together with using a nanotube emitting cathode 31 , allows for further miniaturising the vacuum gauge according to the invention. The cathode 31 and the grid 33 may be spaced apart by tens of micrometres (for instance, 20 to 50 μm), and the distance between the grid 33 and the plate 35 may be for instance in a range from 100 to 500 μm, depending on the sensitivity needed. Clearly indeed, the greater the spacing between the grid 33 and the plate 35 , the greater the probability of ionisation of the residual gas contained in chamber 10 . In order to further reduce the size of the vacuum gauge according to the invention, in the embodiment shown in FIG. 4 , two magnets 25 (for instance, electromagnets or permanent magnets), formed by grounded plane discs or plates, are located between the grid 33 and the plate 35 , in planes perpendicular to both the electrodes 33 , 35 and hence parallel to the initial direction of the electron beam. The magnetic field produced by the magnets 25 affects the motion of the electrons, which follow spiral paths. Thus, the number of collisions of each electron with the atoms or the molecules of the residual gas per unit of linear distance travelled is increased. In other words, with a same geometry, the ionisation degree of the gas, and hence the sensitivity of the vacuum gauge according to the invention, are increased. In the alternative, the distance between grid 33 and plate 35 (and hence the overall dimensions of the vacuum gauge according to the invention) can be reduced, while leaving the ionisation degree of the residual gas and the vacuum gauge sensitivity unchanged. Turning now to FIG. 5 , there is shown a third embodiment of the vacuum gauge according to the invention, which differs from the previous ones in a shape of the grid-shaped anode, here denoted by reference numeral 133 . The anode 133 is made as a substantially parallelepiped cage, having a face 133 a parallel to the cathode 31 and located at a short distance therefrom. Thus, the electrons emitted by cathode 31 are accelerated through the face 133 a of anode 133 according to a preferential initial direction (denoted by arrow F), substantially perpendicular to the plane of said face 133 a. Collecting plate 35 is placed opposite to face 133 a , in correspondence of open base 132 of grid 133 . Note that using a parallelepiped grid 133 allows for increasing the vacuum gauge sensitivity. Actually, being both plate 35 and the walls of chamber 10 grounded, the ions could be attracted by the walls rather than by plate 35 , thereby creating an ion dispersion effect. Use of the parallelepiped grid 133 , which is closed except for the opening 132 in correspondence of the plate 35 , allows for avoiding ion dispersion and consequently increasing the vacuum gauge sensitivity. Turning now to FIG. 6 , there is shown a fourth embodiment of the vacuum gauge according to the invention, which differs from the previous ones in the arrangement of collecting plate 35 . In the previously disclosed embodiments, the plate 35 is placed opposite to cathode and lies in a plane substantially parallel to the cathode itself and perpendicular to preferential direction F of the electron beam. On the contrary, in the embodiment of the vacuum gauge according to the invention shown in FIG. 6 , plate 35 lies in a plane substantially perpendicular to the plane of cathode 31 , and hence it is located in a plane parallel to preferential initial direction F of the electron beam. Thus, the ions and the ionised molecules attracted towards the plate 35 move towards the plate in a direction substantially perpendicular to that of the electron beam. Thus, interactions between the electron source (cathode 31 ) and collecting plate 35 are limited. More particularly, the photoelectric effect on plate 35 due to X-rays emitted by grid 133 ′ is significantly limited, whereby the sensitivity of the vacuum gauge according to the invention is further increased. In this embodiment, grid-shaped anode 133 ′ is suitably equipped with a side opening 132 ′ in correspondence with collecting plate 35 . An extracting device 37 may be provided in correspondence with opening 132 ′ to make ion channelling towards plate 35 easier. The extracting device may comprise, for instance, in an electrostatic lens and it is connected to a power supply 16 , such that the extraction device can be brought to a potential intermediate between the potentials of plate 35 (that is grounded) and grid 133 ′. This embodiment may be provided with a pair of magnets 25 in order to create a magnetic field causing the electrons to move along spiral paths. In the plate-shaped magnets 25 are advantageously located in planes perpendicular to both cathode 31 and plate 35 . In order to limit the background current due to photoelectric effect of the plate caused by X-rays produced on the grid and, hence, to improve the sensitivity of the vacuum gauge according to the invention, it might be advantageous to place collecting plate 35 at a greater distance from grid-shaped anode 133 ′. To this aim, means such as magnets, capacitor plates, electrostatic lenses, radiofrequency devices, capable of deflecting a beam of charged particles, could be used. Turning to FIG. 7 , there is shown a fifth embodiment of the invention, in which a capacitor 45 is provided, of which plates 47 are suitably biased so as to channel between them the ions or the ionised molecules, so as to deflect their advancing direction by about 90°. More particularly, one of the plates 47 may be grounded and the other may be brought to a suitable potential to obtain ion paths with the desired curvature radius. The electrons accelerated by anode 133 ′ collide with the atoms or the molecules of the residual gas and ionise them. The ions or the ionised molecules are channelled into the space between plates 47 of the capacitor 45 and are deflected by 90° towards a plate 35 placed at the exit from the passageway defined between the plates 47 . Similarly, in a sixth embodiment of the vacuum gauge according to the invention, shown in FIG. 8 , a capacitor 49 may be provided, located between extracting device 37 and collecting plate 35 and having plates 51 that are shaped so as to deflect the direction of the ions or the ionised molecules by about 180°. The ions or the ionised molecules produced by the collisions of the electrons accelerated by anode 133 ′ are channelled between plates 51 of the capacitor 49 and are deflected by 180° towards the plate 35 placed at the exit from the passageway defined between the plates 51 . Advantageously, according to the latter two embodiments, collecting plate 35 is isolated from the electron beam and the electron source, so that the photoelectric effect due to X-rays produced on grid 133 ′ is significantly reduced. In the latter two disclosed embodiments described above, a pair of shaped magnets might be used in place of a capacitor for deflecting the ions. In such case, electrical potential V m between said magnets will be chosen depending on the curvature radius desired for the ion paths, according to relation: m/q=r 2 B 2 /2(V 133′ −V m ), where m and q are the mass and the charge, respectively, of the ions to be deflected; r is the desired curvature radius; B is the strength of the magnetic field generated by said magnets and; V 133′ is the potential of grid 133 ′. The skilled in the art will immediately appreciate that the use of the vacuum gauge of the present invention gives important advantages. First, the possibility of constructing a vacuum gauge of substantially reduced size makes the vacuum gauge suitable for any field of application. Still due to its reduced size, the vacuum gauge does not perturb the environment where pressure is to be measured, so that said measurement is more reliable and accurate. It is clear as well that the above description has been given only by way of non-limiting example and that changes and modifications are possible without departing from the scope of the present invention as claimed.

An ionisation vacuum gauge for measuring the residual pressure of a gaseous material remaining in a container ( 10 ), more particularly after operation of a vacuum pump comprises an electron-emitting cathode ( 31 ) made by exploiting the nanotube technology, a grid ( 13; 33; 133; 133 ′) for accelerating the electrons emitted by the cathode, and a plate ( 15; 35 ) collecting the ions and/or the ionised positive molecules of the gas. Measuring the plate current by a galvanometer allows for determining the value of the residual pressure inside the container.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates, generally to electro-medical devices. More particularly, the invention relates to improved implantable electrodes for interfacing with human body tissue and resulting improved electrical therapeutic systems. The invention has particular utility in implantable cardioverter-defibrillators. However, the invention also may be found to have utility in other applications such as neural stimulation or stimulation of non-cardiac muscle tissue. 2. Background Information The development of defibrillators over the past thirty years was thoroughly described in U.S. Pat. No. 5,143,089 issued to Eckhard Alt. Alt's electrode, made from a bundle of synthetic fibers, began to address the need for electrodes interfacing with body tissue which have large surface area, low polarization, and little intrinsic stiffness with the capacity for good communication and high current over long life. Carbon is among the suitable materials for the fibers disclosed in the Alt '089 patent. Carbon fiber is well suited for processing into interlaced forms, and has been the subject of further development. The Alt '089 patent suggested a woven flat patch or a tubular woven structure made from the fibers. Dr. Alt continued development and testing of fiber defibrillator electrodes. In U.S. Pat. No. 5,411,527, Alt disclosed the use of tiny metallic fibers having a smooth uniform coating of carbon on them. In U.S. Pat. No. 5,433,730, Alt disclosed a conductive pouch electrode where the pouch has "an effective electrical surface area considerably larger than its geometric surface area." Electrodes must have some way of being connected to a power source. This is usually done by connecting one end of a metal lead to the electrode and the other end to the power source. The '089 patent does not discuss how the fiber electrode is connected to the lead attached to it, and it shows a lead being connected only at one end of the fiber electrode. The '089 patent disclosed electrodes made completely of carbon fiber, and some of the configurations had the fiber bundles interwoven. Such a structure requires electricity to be conducted through the connection between the lead and the electrode and to be conducted throughout the electrode by the carbon fiber filaments themselves. While carbon fiber does conduct electricity, it is not as good a conductor as metal. Consequently, there can be some significant voltage gradient down the length of the electrode. A voltage that is below the minimum threshold needed to induce defibrillation is ineffective. If a voltage gradient along the electrode causes a section of the electrode to have a voltage below this minimum, that section of the electrode is ineffective. It is an object of the present invention to provide a carbon fiber and metallic conductor electrode which has higher conductivity than electrodes made only of carbon fiber. It is a further object of this invention to provide a method of connecting a carbon fiber electrode to a metallic lead that maintains the structural integrity of the carbon fiber electrode and provides redundant electrical paths between the electrode and the lead. It is a further object of this invention to provide an electrode which is more efficient in transferring energy to living tissue, particularly a heart. It is a further object of this invention to provide a high efficiency electrode which is flexible and three dimensional. It is a further object of this invention to provide an electrode which requires lower energy to accomplish defibrillation of a heart. It is a further object of this invention to provide an electrode which allows energy sources used with it to have longer useful lives. It is a further object of this invention to provide an electrode which allows energy sources used with it to be smaller. It is a further object of this invention to provide an electrode for defibrillation of a heart which can be used in combination with many other electrodes. SUMMARY OF THE INVENTION The present invention provides an improved electrode structure and attached lead for defibrillation. The improved structure provides increased conductivity over carbon fiber electrodes and eliminates any significant voltage gradient along the electrode by 1) interspersing highly conductive metal wire, preferably made of platinum-iridium, among the carbon fiber bundles, or coating outer fibers with conductive metal and 2) connecting the fiber electrode at both ends to an electrical lead in a manner that maintains the structural integrity of the fiber electrode and provides redundant electrical paths between the electrode and lead. The fiber electrode configuration provides a low polarization, low capacitance, low resistance, and low impedance electrical interface with body fluid and/or excitable tissue in contact with or in the immediate vicinity of the electrode. The electrode has a distal end and a proximal end, is flexible, and, in the preferred embodiment, is comprised of a multiplicity of uninsulated current-conducting fibers and wires. Those fibers and wire are braided to maintain the electrode's shape. The fibers together provide an effective surface area for the electrical interface which is considerably larger than the apparent actual surface area of the electrode as determined from the linear dimensions of said electrode. In an alternate embodiment, there is no wire braided with the fibers, rather the fibers exposed on the surface of the electrode are coated with a thin layer of titanium followed by a thin layer of silver. The fiber electrode is attached to a conductive lead at both ends of the electrode by swaging a compression ring of platinum-iridium over the ends of the electrode. That makes a good electrical and mechanical connection between the electrode and the lead and the platinum-iridium is soft enough to not damage the carbon fiber during the swaging process. In one embodiment of the invention, the electrode and attached lead are tubular to facilitate its use for heart defibrillation in combination with a different type second electrode and attached lead used for pacing or sensing the heartbeat. The second electrode is mounted distally with respect to the tubular defibrillation electrode. The lead attached to the second electrode runs coaxially inside the tubular defibrillation electrode and inside of the first lead for a substantial length of the first lead. The two coaxial leads are terminated in a manner well known in the industry to connect to an energy source not a part of this invention. In another embodiment of the present invention, a tubular braided fiber electrode has a distal fitting attached to one end of it and a proximal fitting attached to the other end. The proximal fitting can be configured in any manner to facilitate connection to an energy source or another lead not a part of this invention. Both fittings may be tubular to allow additional leads for additional electrodes to pass through the bore of the braided fiber electrode. The preferred tubular construction of the electrode of the present invention allows ancillary structures than electrodes to be used in conjunction with the electrode. Such structures include drug dispensers and fiber optics. The features, benefits and objects of this invention will become clear to those skilled in the art by reference to the following description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall view of the preferred embodiment of the composite electrode and lead of the present invention as used in conjunction with a pace/sense electrode. FIG. 2 is a view partially in cross section of the preferred embodiment shown in FIG. 1. FIG. 3A is a cross sectional view of the distal end of the preferred embodiment shown in FIG. 1. FIG. 3B is a cross sectional view of an alternate embodiment of the distal end shown in FIG. 3A. FIG. 4 is a cross sectional view of the proximal end of the preferred embodiment shown in FIG. 1. FIG. 5 is an illustration of and alternate embodiment of the fiber conductor of the present invention using titanium and silver coatings on the carbon fiber electrode. FIG. 6 is an illustration of a braiding machine used to make the fiber conductor of the present invention. FIG. 7 is a cross sectional view of an alternate embodiment of the present invention. DETAILED DESCRIPTION 1. General Principles A) Improved Conductivity One aspect of the invention is the improved conductivity of the carbon fiber electrode. Pyrolized carbon and platinum-iridium have been used for pacemaker electrodes which operate in the 2.5 to 5 volt range. Both materials are low-polarizing, which reduces energy consumption. Carbon in fiber form provides added advantages of flexibility, strength, and most importantly, a very large surface area. Each filament of carbon fiber can have a diameter of about 10 microns. A bundle of filaments, called a tow, having about 1000 filaments, has a diameter of about 0.2 mm and a total surface area of about 3 square centimeters per centimeter of tow length. This is particularly advantageous for defibrillation where several hundred volts are applied. To apply such voltage to cardiac tissue without inflicting local bums requires electrodes with surface areas of 50 to 100 square centimeters. With tows of carbon fiber, only a few centimeters of material are needed to provide the required surface area. This means a carbon fiber electrode can be much smaller than conventional electrodes, making implantation easier. Furthermore, the high flexibility of carbon fiber allows maximum myocardial contact upon movement of the heart, and minimum restriction of the myocardial function. However, carbon fiber is not a very good conductor. Consequently, an electrode made only of carbon fiber may show a voltage gradient which could be detrimental to the functioning of the electrode. To improve the conductivity over carbon fiber electrodes, the present invention preferably intersperses highly conductive wire among the carbon fiber tows during the process of forming the electrode. The wire used in the preferred embodiment was 90/10 platinum-iridium. When the carbon fiber bundles and wire are woven or braided into a structure, the resulting structure has multiple redundant paths of high conductivity formed by the intersecting wires. There is essentially a "mesh" of highly conductive material (wire) with lower conductive material (carbon fiber) in the spaces of the mesh. The finer the mesh, the lower the voltage gradient in the carbon fiber. The result is an electrode with the advantages of the fiber electrode made only from carbon fiber, but with a higher conductivity, and thus a lower voltage gradient. In a test performed to verify the higher conductivity, a multimeter measured the resistance of 1) platinum iridium wire (9/49 style), 2) a braided tube made of carbon fiber (16 tows of Toray T-300 1K fiber), and 3) a braided tube made from 12 tows of Toray T-300 1K carbon fiber and 4 strands of 9/49 platinum iridium wire. The resistance of the platinum iridium wire itself was 1.1 ohms/ft. The resistance of the tube made from only carbon fiber was 11.2 ohms/ft. The resistance of the tube made from carbon fiber and platinum iridium wire was 4.0 ohms/ft. The high surface area of carbon fiber and the increased conductivity from the addition of the wire result in an electrode that requires lower voltages and energies to achieve defibrillation. The present invention preferably uses a combination of platinum-iridium wire and carbon fiber tows (PIC) braided together in a tubular form. It is well suited for use where a combination endocardial and epicardial electrodes are used for defibrillation. The present invention was tested in the endocardial configuration and position. The PIC electrode was one of three endocardial electrodes tested in combination with the two epicardial electrodes on dogs' hearts to determine the most effective combination for defibrillation. The epicardial electrode attached to the outside of the heart was either a conventional titanium patch or a braided tubular carbon fiber electrode attached in a U shape describing the outer bounds of the patch. The endocardial electrode was placed at a location inside the heart. The results of the testing showed that of the two epicardial electrodes, the braided carbon fiber electrode reduced the energy required to achieve defibrillation 39 to 56 percent, and lowered the voltage required 24 to 35 percent over the titanium patch. The greatest reduction was achieved with the PIC electrode for the endocardial electrode. Of the three endocardial electrodes, the PIC electrode also produced the lowest defibrillation energies for both the titanium patch and the braided carbon fiber electrode. B) Connection to Lead Another aspect of the present invention is way the metal lead is attached to the fiber electrode. A swage joint is made preferably at both ends of the fiber electrode so the fiber electrode is attached to the lead at two places. That provides redundant electrical paths between the electrode and the lead and further reduces the voltage gradient along the electrode. The resultant low capacitance electrode has low polarization and better coupling to provide low energy loss at the electrode-lead connection. The swaging operation compresses a metal swage ring onto the ends of the braided fiber tube. A metal internal tube segment supports the braided fiber during this operation. The swage ring material must be very soft to flow around the carbon fiber and not fracture it. If the swage ring material is not soft enough, locally high compression forces can damage the fiber. This is different from swaging metal braided tubes where the metal braid will deform along with the swage ring to make a unitized structure. With carbon fiber braided tubes, if too high a compressive load is applied, the fiber will fracture resulting in a poor electrical connection. If the fracturing is severe enough, the swaged end may break away from the rest of the structure. The present invention preferably uses a 90/10 platinum iridium material for the swage ring. That material is soft enough to make a good swage joint without significantly damaging the fiber. Pure annealed platinum, which is even softer could also be used, or any conductive, malleable, non-reactive metal such as gold or rhodium alloys. 2. Preferred Embodiments Referring to the drawings, where like reference numerals designate like or similar elements throughout, a preferred embodiment of the invention is illustrated in FIGS. 1 through 4. Referring to FIG. 1, a composite electrode assembly 12 of the present invention is used in conjunction with a pace/sense electrode assembly 16 and transmission section 14 to form part of an implantable assembly 10. The electrode assemblies 12 and 16 are positioned near the tissue to be stimulated and ideally in contact with the tissue to be sensed. Transmission section 14, which can be any length, carries leads (not shown) connected to electrode assemblies 12 and 16. Terminations of the leads are made in any manner well known in the industry to connect to an energy source, and are not a part of this invention. The composite electrode assembly 12, has a distal end 20, and a proximal end 24 with approximately 5 cm of exposed conductor 22 between them. The conductor 22 constitutes the defibrillation electrode and, in the preferred embodiment, is a structure made of carbon fiber and conductive metal wire braided together. Referring to FIG. 2, leads 30 and 52 are coiled wire which run essentially the entire length of the implantable assembly 10. The coiled configuration of these leads provides great longitudinal flexibility making it easy for surgeons to manipulate the implantable assembly 10. It also provides great radial stiffness to resist crushing when handled by people and surgical instruments. Lead 52 runs coaxially inside lead 30, and the two are electrically and mechanically separated by insulating tubing 58, such as polyurethane. One end of lead 52 is mechanically and electrically fastened to electrode 50, which is a pace/sense type electrode. One end of lead 30 is mechanically and electrically fastened to conductor 22 at both ends of conductor 22 by distal compression ring 40 and proximal compression ring 42. A piece of insulating tubing 36 is also optionally installed over lead 30 at the location of the braided conductor 22 to make it easier to slip braided conductor 22 over lead 30. A length of insulating tubing 80 sheaths lead 30 in transmission section 14. Leads 30 and 52 can be any length and can be terminated in many configurations to meet requirements of mating parts. The implantable assembly 10 provides a compact package of a most efficient defibrillator electrode assembly 12 and a pace/sense electrode assembly 16. The conductor 22 of defibrillator electrode assembly 12 provides a high voltage shock to a fibrillation heart to restore normal rhythm. The pace/sense electrode 50 of the pace sense electrode assembly 16 senses the natural electrical signal produced by a beating heart and/or provides a low voltage stimulation to maintain a desired pace of the heartbeat. A device of this configuration can easily be placed in the desired location to provide part of the electrical stimulation and sensing needed to control a malfunctioning heart. At least one other electrode is needed to complete the defibrillation circuit. That could be provided by another device of this configuration attached at a different location, or by some other electrode configuration. The method of construction of the composite electrode assembly 12 of the preferred embodiment of the device is shown in FIGS. 2, 3A, and 4. Referring to FIG. 3A, the distal end 20 is assembled as follows. An appropriate length of coil lead 30 is selected. In the preferred embodiment it was Quadrifilar MP35N/AG 0.054 in. dia. Distal crimp, tube 32 is inserted in the end of lead 30 and distal crimp fitting 34 is slid over end of lead 30, aligned with distal crimp, tube 32, and crimped in place. In the preferred embodiment, a length of 0.056 in. ID×0.066 in. OD insulating robing 36 is optionally slid over lead 30 so that it butts against distal crimp, fitting 34. The braided carbon fiber/conductive metallic wire conductor 22 is cut to an appropriate predetermined length and slid over optional tubing 36 so that the distal end of braided conductor 22 is disposed over part of distal crimp fitting 34 and butts against shoulder 38 of distal crimp fitting 34. Distal compression ring 40 is aligned with distal crimp fitting 34 and the distal end of braided conductor 22 and swaged in place to secure the distal end of braided conductor 22. Referring to FIG. 4 the proximal end 24 is assembled as follows. The proximal compression ring 42 is slid over the proximal end of braided conductor 22, approximately beyond its final terminal point. Proximal crimp fitting 44 is slid over lead 30 and under the proximal end of braided conductor 22 so that the end of braided conductor 22 butts against shoulder 46 of proximal crimp fitting 44. Proximal crimp fitting 44 is crimped to lead 30. Proximal compression ring 42 is slid back into position over the proximal end of braided conductor 22 and proximal crimp fitting 44 and swaged in place. Insulating tubing 80, preferably 0.056 in. ID×0.076 in. OD, is slid over lead 30 and butted against proximal crimp fitting 44. Insulative robing 48, preferably silicone rubber, preferably 0.058 in. ID×0.077 in. OD, is applied to cover the end of tubing 80, compression fitting 42, and the end of braided conductor 22, then bonded in place with an adhesive such as silicone. Referring to FIG. 3A, a pace/sense electrode 50 is mounted at the distal end of the implantable assembly 10. The composite electrode assembly 12 is tubular, allowing for internal passage of the coil lead 52 connected to the pace/sense electrode 50. In the preferred embodiment, lead 52 is Trifiler MP35N, 0.021 in. ID×0.034 in OD. Electrode 50 is attached to the end of lead 52 by inserting a piece of 0.010 dia. stainless steel wire 54 inside lead 52 as electrode 50 is pushed onto lead 52. The piece of wire 54 expands lead 52 holding it firm against the bore 56 of electrode 50. Insulating tubing 58, preferably 0.024 in ID×0.032 in. OD, is placed over lead 52 so that it butts against electrode 50, then insulative tubing 60, preferably silicone rubber, preferably 0.058 in. ID×0.077 in. OD, is applied over the joint between tubing 58 and electrode 50 and bonded in place with an adhesive 62, such as silicone. Collar 64 is bonded to electrode 50 with adhesive 62. Collar 64 facilitates tissue growth around it to help anchor the pace/sense electrode assembly 16 in the heart muscle. Lead 52 with tubing 58 and electrode assembly 16 attached is inserted into distal crimp tube 32 of the composite electrode assembly 12 and pushed down the length of the lead 30. The insulating tubing 58 electrically insulates the two coils. When insulative tubing 60 butts against crimp tube 32, another piece of insulative tubing 66 is installed over distal crimp fitting 34 and distal compression ring 40, so it overlaps insulative tubing 60 and it is bonded in place with adhesive such as silicone. An alternate embodiment of the pace/sense electrode assembly 16 is shown in FIG. 3B. Pace/sense electrode 70 is modified by boring hole 72 all the way through it and shortening the length from shoulder 74. This makes it easier to install wire 76 because it can be installed from the outside end, then hole 72 sealed with an adhesive 78 such as silicone. The rest of the assembly is as shown in FIG. 3A and described above. Composite electrode conductor 22 is made in the preferred embodiments by braiding twenty-four tows of carbon fiber, preferably Toray T-300 1K and eight strands of conductive metallic wire, preferably 90/10 platinum iridium 9/49 style over a solid plastic core of 0.063 in. diameter. In an alternate embodiment of conductor 22, thirty-two tows of carbon fiber are braided and no conductive metallic wire. In that embodiment, the outside of conductor 22 is coated with a layer of tungsten followed by a layer of silver. Referring to FIG. 5, tows 84 of carbon fiber are intertwined by the braiding process. Each tow has 1000 filaments 86. The titanium 88 and silver 90 coatings are applied only to the outer filaments 86 exposed of the outer tows 84 exposed by the braiding process. Coatings 88 and 90 are applied by vacuum deposition. The total coating thickness on the carbon filaments 86 is approximately 2 microns. Braiding is done in a continuous operation as illustrated in FIG. 6. Braiding machines are well known in industry, so the description here is only illustrative. Core material 202 is unwound from a supply spool 204 and fed up through tube 206, around wheels 208 and 210, and onto take-up spool 212. Fiber 214 from spools 216 mounted on table 218 is fed through carriers 220 and through guide 222. As wheel 208 advances, carriers 220 move in a serpentine path to braid fiber 214 over core 202. Controlling the speed of the carriers 220 relative to that of wheel 208 controls the braid pattern. The length of the braid is limited only by the length of core 202 on spool 204 and the lengths of fiber 214 on their spools 216. There are many configurations for the leads connecting to conventional defibrillator and pace/sense electrodes. There are also other structures which can go inside a tubular defibrillation electrode such as drug dispensers and fiber optics. To accommodate leads of any configuration, and any additional structures inside the electrode, an alternate embodiment of the invention is as follows. Referring to FIG. 7, on distal end 120, lead 130, distal crimp tube 132, distal crimp fitting 134, insulating tubing 136, braided conductor 122, and distal compression ring 140 are assembled as shown and described in the preferred embodiment of FIGS. 3A and 4. Insulative tubing 166 can be installed at this time or after the desired electrode or other structure is installed. At the proximal end 124, lead 130 is cut to a predetermined length to accommodate fittings at this end of the electrode. A proximal crimp tube 143 is inserted inside the proximal end of lead 130. Proximal compression ring 142 and proximal crimp fitting 144 are installed as shown and described in the preferred embodiment of FIGS. 3A and 4. Insulative tubing 148 is installed and bonded with silicone rubber adhesive for example. Proximal crimp fitting 144 has a connector end 146 that can be configured to one of several different mating connector designs per customer requirements. This assembly is hollow to accommodate a plurality of additional conductors or other structures passing through it. The invention as shown in these embodiments provides a compact package of a most efficient defibrillator electrode specifically designed to be used with at least one additional device. One embodiment shows how the defibrillator electrode of the present invention is used with a pace/sense electrode. The defibrillator electrode provides a comparatively high voltage shock to a fibrillating heart to restore normal rhythm. The pace/sense electrode senses the natural electrical signal produced by a beating heart and/or provides a low voltage stimulation to maintain a desired pace of the heartbeat. The increased efficiency of the defibrillator electrode allows current battery packs to last longer or the same useful life to be obtained from smaller battery packs. It also allows the defibrillator electrode to be much smaller than conventional defibrillator electrodes. A device as shown in these embodiments can easily be placed in the desired location to provide part of the electrical stimulation and sensing needed to control a malfunctioning heart. At least one other electrode is needed to complete the defibrillation circuit. That could be provided by another device of this configuration attached at a different location, or by some other electrode configuration. The descriptions above and the accompanying drawings should be interpreted in the illustrative and not the limited sense. While the invention has been disclosed in connection with the preferred embodiment or embodiments thereof; it should be understood that there may be other embodiments which fall within the scope of the invention as defined by the following claims. Where a claim is expressed as a means or step for performing a specified function it is intended that such claim be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof; including both structural equivalents and equivalent structures.

An implantable assembly for defibrillation and monitoring and/or regulating the beat of a heart. The defibrillation electrode is flexible and preferably made of braided carbon fiber and conductive metallic wire. It provides a low polarization, low capacitance and low impedance electrical interface with body fluid and/or excitable tissue. The conductivity of the defibrillation electrode is increased over electrodes made only of carbon fiber by the presence of the conductive metallic wire in the preferred embodiment, or by a thin exterior coating of titanium and silver in another embodiment. This electrode delivers energy more efficiently to body tissue than conventional defibrillation electrodes, resulting in lower energy needed to achieve defibrillation, which allows batteries powering the defibrillator to last longer. The fibers together provide an effective surface area for the electrical interface which is considerably larger than the apparent actual surface area of the electrode as determined from the linear dimensions of the electrode. This lows the electrode to be smaller than conventional defibrillation electrodes. The preferred configuration of the defibrillation electrode is tubular, which can be used with at least one additional device, such as a second electrode for pacing or sensing the heartbeat, to be mounted on the distal end of the defibrillator electrode. Lead(s) connected to the additional device(s) pass through the defibrillator electrode and run inside the lead connected to the defibrillator electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2004-111281 filed on Apr. 5, 2004; the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a pulley and a power transmission device using the same, and more specifically to a pulley and a power transmission device, which are suitable for use in driving a compressor built in a refrigeration cycle of a car air conditioner. [0004] 2. Descriptions of the Related Arts [0005] For example, a power transmission device having a torque limiter function is disclosed in Japanese Patent Laid-Open No. Hei 8 (1996)-135752. This power transmission device includes a pulley as a driving-side rotation member driven upon receipt of power from an engine. The power transmission device includes a hub as a driven-side rotation member, which is disposed coaxially in parallel with the pulley and rotatably driven by the pulley. The pulley and the hub have an engaging mechanism having a torque limiter function therebetween. The engaging mechanism links the pulley and the hub and transmits rotation torque to the hub during normal driving. The engaging mechanism releases the link between the pulley and the hub during an abnormal time, for example, at the time of locking due to seizing failure of a compressor. Thus, breakages of other portions in the power transmission device are prevented during the abnormal time. [0006] To be concrete, the engaging mechanism includes a metallic pin pressed into a press hole of the pulley made of metal. The engaging mechanism includes a metallic holding member fixed to the hub. The engaging mechanism includes an elastic body that is linked to the pin and held in a clearance of the holding member. During normal driving, the elastic body links the hub and the pulley while being held in the clearance of the holding member. During abnormal driving, the elastic body is deformed elastically, and slips through the clearance of the holding member to release the link between the hub and the pulley. [0007] In this device, if the pulley made of a metal is changed to a pulley made of a resin, the device is preferably lightened. However, extremely large rotation torque is applied to the pin provided in the pulley. Accordingly, there is no other choice but to adopt a pulley made of metal in terms of the structure of the device, in order to use the device over a prolonged period so that the pin does not fall down even if the large rotation torque is applied to the pin. For this reason, a change from the metallic pulley to the resin pulley has not been considered. [0008] On the condition that the device has a structure that the press hole for pressing the pin thereinto is provided in the resin pulley and the pin is pressed thereinto, even if a design precision of the pin and press hole is made extremely high, sufficient fastening power can not be obtained due to difference of a thermal shrinkage factor between the pin and the resin pulley. If a resin pulley is adopted, which is made in such a manner that pins are located in predetermined positions in a metal mold and then resin is injected into the metal mold to be insert molded, the fastening power between the resin pulley and the pins decreases by shrinkage of the melted resin at the time the resin solidified. SUMMARY OF THE INVENTION [0009] An object of the invention is to provide a pulley made of a resin in which a pin does not fall down even when a large rotation torque is applied thereto. [0010] The first aspect of the invention provides a pulley configured to receive a torque from a drive source for rotation. The pulley includes a resinous pulley body having a belt engagement portion on the outer periphery of the pulley body. The pulley includes a base plate integrally provided to a pin protruding from the pulley body at a predetermined position to engage another member other than the pulley and being insert molded within the pulley body. [0011] The second aspect of the invention provides a power transmission device. The device includes a pulley as a driving-side rotation member to receive a torque from a drive source for rotation. The device includes a driven-side rotation member arranged coaxially parallel to the pulley to be rotatably driven by the pulley. The device includes a link mechanism. The link mechanism includes a pin protruding from the pulley toward the driven-side rotation member. The link mechanism includes a link member provided to the driven-side rotation member and engaging the pin of the pulley. The link mechanism transmits a driving force form the pulley to the driven-side rotation member. The link mechanism cuts off the driving force to be transmitted when the driven-side rotation member has a drive load over a predetermined value. The pulley includes a resinous pulley body having a belt engagement portion on the outer periphery of the pulley body. The pulley includes a base plate integrally provided to a pin protruding from a pulley body at a predetermined position to engage another member other than a pulley and being insert molded within the pulley body. [0012] Two or more pins may protrude from the base plate. [0013] The base plate may include a protrusion piece protruding in a direction crossing a direction of rotating the pulley. [0014] The pulley may include a bearing as an insert component located on the inner periphery of the pulley and insert molded within the pulley body. The base plate has a fitting-into opening having the outer periphery of the bearing fitted thereinto. The base plate and the bearing as insert components are insert molded within the pulley body, with the base plate and the bearing fitted with each other. [0015] The base plate may have windows. [0016] The base plate and the bearing may include engagement portions engaging with each other for preventing relative rotation between the base plate and the bearing. The base plate and the bearing as insert components are insert molded within the pulley body, with the base plate and the bearing joined each other. [0017] According to the first and second aspects, unlike in the case of a structure where pins are merely insert molded in a pulley main body, the structure is adopted, where the base plate having the pins provided integrally therewith is insert molded in the pulley main body. In this structure, the base plate functions as a base of the pins within the pulley main body, thus enhancing connection strength between the pins and the pulley main body. Therefore, even when a large load is applied to the pins from another member, this structure prevents the pins 24 from falling down out of the pulley main body made of resin, and from coming off out of the pulley main body. The structure achieves lighter resin pulley, with abolishing a metallic pulley, and a lighter power transmission device. [0018] The pins protruding from the base plate does not require insert molding of separately retained pins in the pulley main body, thus facilitating manufacture of the pulley. [0019] The base plate includes the protrusion piece protruding in the direction crossing the rotation direction of the pulley, and the structure enhances rotation-preventing force of the base plate within the pulley body, thus providing a structure where the pin hardly falls down. [0020] The fitting-into opening of the base plate serves as a positioning guide of the base plate, thus facilitating the positioning of the pins. [0021] The windows formed to the base plate allow melted resin to flow through the windows of the base plate if the base plate exists within the metal mold during the insert molding, thus suppressing deterioration in flowability of the melted resin as low as possible. The structure enhances connection strength between the pulley main body and the base plate [0022] The base plate and the bearing include engagement portions engaging each other to prevent relative rotation between the base plate and the bearing, and the base plate and the bearing are insert-molded as insert components, with the base plate and the bearing connected. Therefore, the bearing and the base plate are mechanically connected before they are molded with a resin. In other words, in the pulley made of a resin, the base plate functions as a flange portion protruding from the external circumference of the bearing. This structure enlarges a contact area of the pulley main body and the bearing, thus enhancing the connection strength between the bearing and the pulley body. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS [0023] FIG. 1 is a side view of a substantial part of a power transmission structure according to a first embodiment of the present invention; [0024] FIG. 2 is a longitudinal section view of a power transmission device of FIG. 1 ; [0025] FIG. 3 is a schematic perspective view of a resin pulley used for the power transmission device of FIG. 1 ; [0026] FIGS. 4A and 4B are perspective views illustrating an assemble state of a bearing and a board as an insert component; [0027] FIG. 5 is an illustrative view of an assemble method of the power transmission device of FIG. 1 ; [0028] FIG. 6 is a side view illustrating a substantial part of the power transmission device of FIG. 1 after power shutoff; [0029] FIG. 7 is a perspective view illustrating a first modification of a pulley board of FIG. 3 ; [0030] FIG. 8 is a perspective view illustrating a second modification of the pulley board of FIG. 3 ; [0031] FIGS. 9A, 9B and 9 C are section views illustrating a structural example of a pin of the board of FIG. 3 ; [0032] FIG. 10 is a section view illustrating a pulley of another embodiment; [0033] FIGS. 11A and 11B are illustrative views for schematically explaining an assemble state of a board and a bearing insert molded into the pulley of FIG. 10 ; [0034] FIG. 12 is a view for illustrating an appearance as a comparison example, which shows that a pin is insert molded with a resin; and [0035] FIG. 13 is a block diagram illustrating a compressor system using the power transmission structure of FIG. 1 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0036] Embodiments of the invention will be described with reference to drawings. First Embodiment [0037] An entire structure of a power transmission device 1 will be described. In FIG. 2 , a housing 2 of a clutchless compressor (driven-side rotation member) is provided, and a pulley 20 (driving-side rotation member) is rotatably supported by a boss portion 2 a of the housing 2 . The housing 2 houses a rotation shaft 7 that is coaxially located with respect to the boss portion 2 a and protrudes to the outside from the boss portion 2 a . The rotation shaft 7 has an end portion, and a hub 10 (driven-side rotation member) is fixed to the end portion thereof. [0038] The hub 10 has a plurality of pin insertion holes 11 at predetermined intervals (120° in this embodiment) on the identical circumference locating the rotation shaft 7 at the center. The pin insertion holes 11 have cylindrical pins 13 , a respective one of which is fixed to a corresponding one of the pin insertion holes 11 , while passing through the hole 11 . [0039] As illustrated in FIG. 1 , the pulley 20 has a plurality of cylindrical pins 24 (three pieces in this embodiment) that stand on one end face thereof (on a hub side). The pins 24 are located at predetermined angular intervals (120° in this embodiment) on the identical circumference locating the center point of the pulley 20 at the center. A respective one of the pins 24 of the pulley 20 is linked to a corresponding one of the pins 13 of the hub 10 by use of a link member 12 . [0040] The link member 12 has a leaf spring-like shape fabricated from a spring material such as high carbon steel. The link member 12 is formed by stacking one or more plate members M, which are punched off into a predetermined shape so as to have the identical shape and size, in the thickness direction (see FIG. 1 ). Although the number of the plates M is two in this embodiment, the number of the plate members M may be one. This link member 12 has a forked shape, and includes a pair of opposed side pieces 12 a with a slit-like clearance 16 interposed therebetween. The link member 12 has a through-hole 14 on the lining end side. The through-hole 14 is formed so as to communicate with the clearance 16 and contacts the external periphery of the pin 13 for rotatably engaging with the pin 24 . The link member 12 has, on the open-end side, pinching portions 15 that are formed in the tip portions of the side pieces 12 a and retain the pin 24 therebetween. Each of the pinching portions 15 is structured as a concave curve plane 15 formed along the external periphery of the pin 24 . This concave curve plane 15 has, at both ends, convex portions 17 A and 17 B that contact the external periphery of the pin 24 . The convex portions 17 A and 17 B are formed so as to have a convex circular shape, and only the convex portions 17 A and 17 B in each of the concave curve portions 15 contact the external periphery of the pin 24 . Portions of the concave curve plane 15 other than the convex portions 17 A and 17 B have a clearance from the external periphery of the pin 24 . The distance L 1 between the convex portions 17 A and 17 A on the link end side (base end side) is larger than the distance L 2 between the convex portions 17 B and 17 B on the opening end side (tip end side). The clearance 16 between the pair of side pieces 12 a has the width W 1 that is slightly larger than the diameter of the external periphery of the pin 24 , allowing the pin 24 to be movably housed therein. [0041] When the pulley 20 and the hub 10 are linked in an assembly step of the power transmission device 1 , the link member 12 links the pin 24 of the pulley 20 and the pin 13 of the hub 10 to each other. To be concrete, the pin 13 is first fitted into the through-hole 14 of the link member 12 as shown in FIG. 5 , and the pin 24 is inserted in the clearance 16 of the link member 12 . Subsequently, in a state where the hub 10 is fixed so as not to be rotated, the pulley 20 is rotated (in the arrow direction R 1 ). The rotation allows the pin 24 in the clearance 16 to move to the open-end side, and the pin 24 is pressed into the pinching portions 15 on the open-end side. Thus, the pin 24 elastically deforms the side-pieces 12 a of the link member 12 to be separate from each other, and the pin 24 is pressed between the pinching portions 15 . Finally, the side-pieces 12 a of the link member 12 are elastically restored to an original shape thereof, with the pin 24 retained between the pinching portions 15 of the link member 12 as shown in FIG. 1 . [0042] Next, the operation of the power transmission device structured as above will be described. A power of an engine 101 shown in FIG. 13 is transmitted to the pulley 20 using a belt (not shown), and the pulley 20 is rotated. The rotation of the pulley 20 is transmitted to the hub 10 through the pin 24 , the link member 12 and the pin 13 , permitting the rotation shaft 7 to be rotated. The rotation provides the power of the engine as a driving machine to a compressor 102 as a driven machine for operation. [0043] When seizure and the like are produced within the compressor, causing a load torque to exceed a predetermined value, the pin 24 retained by the pinching portions 15 of each link member 12 spreads out the side pieces 12 a of the link member 12 from each other to separate from the link member 12 . This separation cuts off transmission of the power from the pulley 20 to the rotation shaft 7 for idling the pulley 20 (see FIG. 6 ), without any damage to other portions of the power transmission device 1 in addition to the compressor and the engine. [0044] Herein, operation and benefits achieved by using the link member 12 will be described. [0045] The link member 12 has a structure in which only the convex portions 17 A and 17 B formed in the tips of the pinching portions 15 retaining the pin 24 therebetween contact the external periphery of the pin 24 . This structure permits the pin 24 to be securely retained without wobbling. This structure prevents occurrence of noisy sound and wear of the link member 12 . This structure advantageously stabilizes a force to separate the pin 24 retained between the pinching portions 15 toward the open-end side. [0046] The convex portions 17 A and 17 B have a structure that they are formed in the convex circular shape and have a point contact with the external periphery of the pin 24 . This structure advantageously reduces wear of the convex portions 17 A and 17 B, thus hardly varying force in magnitude to separate the pin 24 from the convex portions 17 A and 17 B. [0047] This structure is that the distance L 1 between the convex portions 17 A on the link end side is larger than the distance L 2 between the convex portions 17 B and 17 B on the open end side. Therefore, the force for opening the side pieces 12 a from each other to press the pin 24 inserted in the clearance 16 between the curve planes 15 and 15 , is smaller than the force for opening the side pieces 12 a from each other to separate the pin 24 retained between the curve planes 15 and 15 toward the open end side. [0048] The link member 12 has a structure where the clearance 16 extending from the open-end side to the link the end side of the member 12 communicates with the through-hole 14 on the link end side. Therefore, when in a linking step, the pin 24 inserted in the clearance 16 is pressed between the pinching portions 15 provided on the open end side of the clearance 16 , the link member 12 deforms over the entire length. This reduces size of the link member 12 . [0049] The link member 12 has a structure constructed by stacking the plurality of plate members M (two in this embodiment) in the thickness direction. The structure facilitates a punching step for the plate member M constituting the link member 12 , thus improving workability, and is hard to produce burr, deformation and the like, for improvement in the dimensional precision of the link member 12 . [0050] The pulley 20 of this embodiment is a resin pulley, and descriptions for the pulley 20 will be described in detail. [0051] The pulley 20 of this embodiment includes a pulley main body 21 made of a resin, which has a belt engagement portion 21 a in the external periphery, as shown in FIGS. 2 and 3 . The pulley 20 includes a bearing 22 as an insert component that is located on the internal periphery side and is insert molded integrally therewith in the pulley main body 21 . Similarly, the pulley 20 includes a metallic base plate 23 as an insert component that is insert molded integrally therewith in the pulley main body 21 . [0052] The base plate 23 is a metallic plate in which the plurality of pins 24 (three in this embodiment) engaging with the link member 12 are formed integrally therewith as shown in FIG. 2 and FIG. 4A As shown in FIG. 4A , the base plate 23 has an annular circular plate having at the central portion a fitting-into opening 23 a , into which the external periphery of the bearing 22 is to be fitted. [0053] The insert-molded member composed of the metallic bearing 22 , the base plate 23 and the resin pulley main body 21 is made in the following manner. As shown in FIG. 4B , an assembled product produced by fitting of the bearing 22 into the base plate 23 is previously located within a metal mold for injection molding (not shown) as an insert component, and a resin is injected into the metal mold. Subsequently, the resinous pulley main body 21 , the metallic bearing 22 and the base plate 23 are united with each other. [0054] Benefits of this embodiment will be described below. [0055] First, according to this embodiment, unlike in the case of a structure where pins are merely insert molded in a pulley main body, the structure is adopted, where the base plate 23 having the pins 24 provided integrally therewith is insert molded in the pulley main body 21 . In this structure, the base plate 23 functions as a base of the pins 24 within the pulley main body 21 , thus enhancing connection strength between the pins 24 and the pulley main body 21 . Therefore, even when a large load is applied to the pins 24 from other members (the link member 12 in this embodiment), this structure prevents the pins 24 from falling down out of the pulley main body 21 made of resin, and from coming off out of the pulley main body 21 . The structure achieves the resin pulley 20 lighter than a metallic pulley, thus reducing weight of the power transmission device 1 . [0056] As an additional benefit, provision of the pins 24 integrally with the base plate 23 facilitates positioning of the pins 24 by use of the base plate 23 as a guide. The base plate 23 functions as a skeleton member of the pulley main body 21 . Accordingly, increase in the strength of the pulley main body 21 is also expected. [0057] Secondly, this embodiment has a structure in which the plurality of pins 24 are provided so as to protrude from the base plate 23 . This structure eliminates necessity to insert mold the plurality of pins 24 to the pulley main body while retaining the pins 24 separately, thus facilitating manufacture of the pulley. As a comparison example, FIG. 12 is an example in which pins 124 are insert molded to the pulley main body 21 , with the pins 124 separately retained. In such a case, it is necessary to use positioning pins 125 and 126 for retaining both ends of the respective pins 124 for each pin 124 , thus rendering a metal insert mold complicated. In FIG. 12 , only one pin 124 is illustrated as a representative of the pins 124 , and illustrations of other pins 124 are omitted. [0058] Thirdly, this embodiment has a structure where the base plate 23 includes the fitting-into opening 23 a for fitting the external periphery of the bearing 22 thereinto. In this structure, the fitting-into opening 23 a of the base plate 23 serves as a positioning guide of the base plate 23 , thus further facilitating the positioning of the pins 24 . Particularly, the embodiment enhances coaxility of the pulley main body 21 , the bearing 22 and the pins 24 . [0059] Next, modifications of the base plate will be described. [0060] FIG. 7 is a first modification of the base plate. The base plate 23 B of the first modification includes protrusion pieces 31 protruding in the direction crossing the rotation direction of the pulley 20 (normal to the rotation direction in this modification, i.e., the axial direction). These protrusion pieces 31 are formed by punching out parts of the base plate 23 B, which is a metallic plate as a material, into approximately like a letter “U”, and by bending the parts thereof to the outside erectly. The punched-out parts by the bending serve as windows 32 . When this base plate 23 B of the first modification is used, the base plate 23 B is structured with the protrusion pieces 31 that protrude in the direction crossing the rotation direction of the pulley 20 . This structure increases a force to prevent a rotation of the base plate 23 B in the pulley main body 21 , thus hardly falling down the pins 24 . [0061] FIG. 8 is a second modification of the base plate. The base plate 23 C of the second modification has a structure where a plurality of windows 41 (three in this modification) are formed. The windows 41 are formed as a fan along the circumferential direction of the base plate 23 C, and thus the base plate 23 C includes an internal periphery portion 42 and an external periphery portion 42 , which are opposite to each other with the windows 41 interposed therebetween. [0062] The use of the base plate 23 C of this second modification decreases the volume of the base plate 23 C made of metal that mounts weight, thus further lightening the pulley 4 and the power transmission device 1 . When the base plate 23 C of the second modification is used, melted resin flows through the windows 41 of the base plates 23 C even if the base plate 23 C exists in a metal mold during the insert molding. Therefore, deterioration in flowability of the melted resin due to the existence of the base plate in the metal mold is suppressed as low as possible. The second modification has also a benefit that the connection strength between the pulley main body 21 and the base plate 23 C is enhanced. Second Embodiment [0063] FIGS. 10, 11A and 11 B show a pulley 20 of a power transmission device according to a second embodiment of the invention. The pulley 20 of the second embodiment includes engaging portions 51 and 52 in the base plate 23 D and the bearing 22 D. The engaging portions 51 and 52 engage with each other to prevent a relative rotation therebetween. More specifically, engaging convex portions 51 protrude radially inwardly from the periphery of the fitting-into opening 23 a of the base plate 23 D, and the convex portions 51 are arranged at equal intervals in the circumferential direction of the base plate 23 D. On the other hand, engaging concave portions 52 are concaved radially inwardly on the external circumference of an external wheel of the bearing 22 D, and the engaging concave portions 52 are arranged at equal intervals in the circumferential direction of the bearing 22 D. [0064] According to the second embodiment, in addition to the benefits of the first embodiment, the structure is that both members 23 D and 22 D are insert molded as insert components, with the base plate 23 D and the bearing 22 D connected. Therefore, as shown in FIG, 11 B, the bearing 22 D and the base plate 23 D are mechanically connected before they are molded with a resin. In other words, in the pulley 21 made of a resin, the base plate 23 D functions as a flange portion protruding from the external circumference of the bearing 22 D. This structure enlarges a contact area of the pulley main body 21 and the bearing 22 D, thus enhancing the connection strength between the bearing 22 D and the pulley main body 21 . Thus, the pins 24 are made to fall down more hardly by virtue of this structure. [0065] In the first and second embodiments, the pins 24 A and the base plate 23 were integrally molded as shown in FIG. 9A . While, the invention is not limited to this, and the pin 24 B may be jointed to the base plate 23 by welding, as shown in FIG. 9B . As shown in FIG. 9C , the pin 24 C may protrude from the base plate 23 by press working while taking a hollow cylindrical shape. The example shown in FIG. 9A has a merit that strength of the pin 24 A is maintained at a high level. The example shown in FIG. 9B has a benefit that the conventional pin 24 B can be diverted without any adjustment. The example of FIG. 9C is advantageous that it is desired to allow the external circumference shape of the pin 24 C to have slight flexure. [0066] In the embodiments, the fork-shaped link member 12 is used as the link member. On the other hand, in the present invention, other link members may be used. Alternatively, other linking means may be used. [0067] In the embodiments, the descriptions were made by exemplifying the power transmission device in which the hub (driven-side rotation member) fixed to the rotation shaft of the compressor of the car air conditioner and the pulley (driving-side rotation member) rotating by the engine are linked. While, the invention may be applied to a power transmission device that links another driven-side rotation members and the driving-side rotation member to each other. [0068] In the embodiment, the pulley used for the power transmission device was described. While, the present invention can be applied to a pulley used for another devices. [0069] Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, in light of the above teachings. The scope of the invention is defined with reference to the following claims.

A pulley is configured to receive a torque from a drive source for rotation. The pulley includes a resinous pulley body having a belt engagement portion on the outer periphery of the pulley body. The pulley includes a base plate integrally provided to a pin protruding from the pulley body at a predetermined position to engage another member other than the pulley and being insert molded within the pulley body.

BACKGROUND OF THE INVENTION The present invention relates to the technical field of electrical capacitors. A considerable proportion of the faults, and more particularly parasitic resistances which occur in electrolytic filter capacitors occur in the hermetic bushings for the terminals and in the latter. At present these terminals are inserted in the form of approximately cylindrical members made from light alloy or aluminium in a cover made from a thermosetting plastic of an aluminium case shaped by extruding. Such terminals are fixed in the cover material at the time of moulding and in each case comprise: A THREADED HOLE FOR RECEIVING A CLAMPING SCREW FOR CONNECTING A LUG TO THE LOAD CIRCUIT; CONNECTING SLEEVES PROVIDED WITH UNEVEN SURFACES WHICH BRING ABOUT A KEYING IN ROTATION AND WHICH ENVELOP THE TIGHTENING TORQUES OF THE SCREW, WHICH IN ADDITION INCREASE THE LENGTH OF THE LEAKAGE PATHS OF THE ELECTROLYTE WITHIN THE CASE; AN INNER CONNECTING MEMBER ON WHICH IS WELDED, RIVETED OR BOTH WELDED AND RIVETED A CONNECTION TO THE INTERNAL CAPACITATIVE MEMBER. As an example, a capacitor having a capacitance of 47,000 μF under a continuous operating voltage of 6 V, a cover with a diameter of 72 mm is provided to seal the case having terminals with a diameter of 11 mm, although the surface area which they occupy only represents 4.7% of that of the cover. In such a capacitor the minimum impedance as a function of the frequency is 10 mOhm and the series resistance introduced by the terminals is 1 mOhm. It can be seen that the cross-section of the terminals is too small to ensure that the heat emitting within the case is correctly removed by these terminals with a good thermal conductivity when the capacitor is subjected to a high alternating current load. The internal connecting lugs can only be fixed to each terminal via a single member. This is troublesome when the number of the said lugs is increased in order to reduce the series resistance and self-induction of the capacitative members produced in the form of coils. Finally, when the capacitor is not connected to the load circuit by means of lugs and cables, but is connected on connecting bars called busbars, the mounting provided by two screws is weak relative to the vibrations which occur. If the capacitor is mounted in this manner in the horizontal position it can oscillate and become detached, so it is necessary to fix it by means of a supplementary clip. SUMMARY OF THE INVENTION The present invention more particularly aims at improving such bushings for terminals and also to improve the terminals themselves. To this end the invention relates to an arrangement which comprises in a cover made of insulating material two secured terminals, whereby each metal terminal has the shape of a polyhedron rectangular pyramid frustum or cone frustum, whereby the said terminals are mutually arranged in such a way that the cross-sections of the two polyhedrons contained in the respective planes of symmetry offering the maximum lengths are located parallel and very close together. Moreover, the said terminals are given the maximum volume compatible with the techniques of moulding. Their face which is exposed to the outside is provided with at least two threaded holes for receiving clamping screws on lugs or bars. Their inner face is provided with at least three joining members with internal connecting lugs. The exposed face can have such a size that it represents 15-40%, for the two terminals together, of the surface area of the insulating cover. With such an arrangement the terminals have a very low series-resistance on the electrical plane, a very low thermal resistance, a very small self-induction, multiple fixing points for the inner connecting lugs, a considerable mechanical rigidity of fixing to the bars and a high reliability of electrical insulation between the terminals and connections of opposite polarities. The following description made with reference to the attached drawings given as non-limitative examples permits a better comprehension of how the invention is put into practice. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows in perspective a terminal according to the invention; FIG. 2 shows a first variant thereof; FIG. 3 shows in analogous manner a second variant; FIG. 4 shows in a view from below the cover of a capacitor case; FIG. 5 shows a section along the line V--V of FIG. 4; FIG. 6 shows a plan view; FIG. 7 shows an exploded perspective view of the case, cover and capacitative windings of a capacitor produced in this way; FIG. 8 shows a perspective view of the assembly of such a capacitor on busbars. DESCRIPTION OF THE PREFERRED EMBODIMENTS The terminal shown in FIG. 1 has a body 1 in the form of an upright frustum of a pyramid with rectangular bases. The smaller base 2 has a projecting peripheral rib and the larger base 3 is also provided with a projecting peripheral rib. From the smaller base project three members 4 which will receive by welding, riveting or both welding and riveting connecting lugs forming the outlets for the capacitative members. On the larger base there are two threaded bores 5 which serve to receive the clamping screws for the external connecting members. This metal terminal is made from refined aluminium or an aluminium alloy compatible with the electrolyte of the capacitor. In FIG. 2 there is an upright prismatic shaped terminal 6, having a rectangular base and in the lateral surface of which are grooves 7 for insertion into the insulating material of a capacitor case cover. Terminal 6 also has on one face three projecting members 4a, and on the other face two threaded bores 5a. While this prism does not have ribs, the bases each have a flat inner projecting connecting sleeve for receiving the connecting members in order to disengage the same from the insulating material of the capacitor case cover. Another configuration is shown in FIG. 3 wherein a terminal 8 is shaped like the frustum of a pyramid and has on its large base a projecting peripheral rib 3a, and two threaded bores 5b, whilst the small base has a peripheral rib 2a which is extended on one side by an elbowed lug or tab 9 for the internal connection to the capacitative members. As can be seen in FIGS. 4-6 a pair of such terminals 1,6 or 8 is inserted in a cover 10 made from a thermosetting plastic material having a phenol or diallyl phthalate resin base, in such a way that ribs 2 and 3 are only partly embedded therein, and therefore project slightly above the inner face 11 and outer face 12 of the insulating material of the cover. The outer face 13 of the projecting rib 3 is contained in the same plane as the homologous face of the adjacent terminal. This plane can be that of the bus bars 14 and 15 shown in FIG. 8 which shows a group of capacitors 17, 17a mounted in parallel. In the case of using pyramidal terminals, the insertion offers good stability of an extended leakage path for the sealing, without it however being necessary to provide a set of ribs on the lateral surface of the pyramid frustum. If a prismatic cross-section, as shown in FIG. 2, is used, the grooves 7 serve to extend the leakage path and for consolidation purposes. In both cases the stability of the mounting is reinforced by the length of the junction surfaces between the solid terminals and the plastic material. The terminals shown offer relatively long rectangular faces. The mutual arrangement is such that the symmetry planes of the two terminals passing through the large axes of the rectangular faces are mutually parallel and as close together as possible, so that it is possible to reduce to a minimum the self-induction reactance, bearing in mind the distance necessary for retaining an adequate insulation. With this close positioning a projecting rib 18 must be provided between the two heads of the terminals which are exposed to the outside, the rib 18 being formed by molding it simultaneously in the plastic material of cover 10. In addition, an inner intermediate rib 19 must be provided for the mechanical and electrical insulation of the positive and negative connecting lugs or tabs of the inner capacitative members connected to members 4. The height of the ribs 18 and 19 may be reduced to the minimum which is compatible with the necessary electrical insulation. As can be seen in FIG. 7, the capacitative coils 20 are connected by their multiple connecting tabs 21 to the different members 4 appropriate for the terminals 1 inserted in the material of cover 10, and the assembly is associated with the case 16 made from aluminium or an aluminium base alloy compatible with the electrolyte, whose edge 22 will be crimped with the interpositioning of a not shown elastic sealing joint on the edge 23 of cover 10. The upper face of the said edge is provided with a circular pointed rib 24 embedded in the material of the joint. The arrangements described hereinbefore offer definite advantages relative to the prior art which can be illustrated by referring to a specific example. In a cover 10 with a diameter of 72 mm the pair of terminals 1 is given a size such that area occupied by heads 13 represents 22% of the total area of the cover. Under these conditions it should be noted that the thermal conductivity, determined according to Fourier's law is 0.176 kcal/m.H° C, whilst with the conventional terminals according to the prior art this thermal conductivity is 0.038 kcal/m.H° C with refined aluminium whose conductivity factor is 196. The series-resistance introduced by the terminals described into the capacitor circuit is 0.2 mOhm. The inner connecting lugs can be connected at several points to each terminal. In a capacitor fixed as shown in FIG. 8 with the axis of its case arranged horizontally via its terminals by means of bolts 25, secured in bores 5, and passing through corresponding holes in busbars 14,15, mechanically excited at its resonant frequency by vibrations perpendicular to the plane containing the locking axes, it can be seen that the mounting is maintained without detachment, whilst in the case of capacitors provided with conventional terminals each locked by a single bolt, play rapidly develops. This considerable decrease in the series-resistance also leads to a considerable decrease in the self-induction reactance. The following table summarises in comparative manner the characteristics obtained with the above-described arrangements compared with those of the prior art: ______________________________________ Arrangement according Prior to the presentCharacteristics art application______________________________________Series-resistance in mOhm 1.0 0.2Self-induction reactance 0.75 0.35in μFHeat removal surface areaby the two terminals as 4.7 22% (can vary froma percentage of the cover 15-40%)areaNumber of fixing points of 2 at least 4external connectionsNumber of fixing points 2 (can vary.sup.6 between 4of internal connections and 8)Behaviour of the mountingto resonant vibrations Becomes Does not becomeorthogonal to the fixed detached detachedcapacitor axis______________________________________ Obviously, as can be seen on reading the above table, the number of fixing points for the internal connections is at least two per terminal and can reach four, whilst the number of fixing points for the external connections is at least two per terminal and can exceed 3. It is also obvious that a terminal in the shape of a pyramid frustum with or without peripheral ribs could be provided with grooves analogous to groove 7 and a prismatic terminal can have besides the grooves, ribs analogous to ribs 2 and 3. Any terminal can also be provided with an elbowed extension such as extension 9 which may or may not extend a rib, and be provided with connecting members. In conclusion, it is pointed out that when much better filtering characteristics are required in pulsating current supply systems, it is necessary to use electrolytic capacitors whose impedance curve as a function of the frequency is much better than that of present-day capacitors. In the extreme case, a capacitor without a series-resistance would give a V-shaped impedance curve, whereof the downward branch corresponds to the "capacitative reactance" and the upward branch to the "self-induction reactance" as a function of the frequency. It can be deduced from this that a filter capacitor on the basis of results comes closer to perfection as its series-resistance and self-induction resistance become proportionately smaller. Therefore such a capacitor becomes capable of ensuring an improved filtering of the frequencies to be eliminated, whilst raising to the maximum the permitted traversing alternating load. The arrangements described hereinbefore lead to such results whilst reducing to a minimum the parasitic self-inductions and series-resistances. It is obvious that without leaving the scope of the invention as defined in the following claims, other changes can be made to the embodiments described hereinbefore.

An electrolytic filter capacitor has two terminals in a molded insulating cover. The terminals are identical and each is shaped as a polyhedron. The terminals which have means for connection to inner parts of the capacitor and to outer members such as bus bars occupy 15 - 40% of the exposed area of the cover. Each terminal has a plane of symmetry in the direction of maximum size which ae parallel and as closely spaced to each other as insulation requirements permit.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of Korean Patent Application No. 10-2013-0131601 filed on Oct. 31, 2013, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. BACKGROUND [0002] The present disclosure relates to a power supply device. [0003] A bidirectional direct current (DC)-DC converter is a type of power converter that controls the flow of power between two power sources in two directions. Here, in the case of a unidirectional converter, two DC-DC converters are required, since a single unidirectional DC-DC converter must be used in each direction of conversion, in order to control the flow of power in two directions. When a bidirectional converter is employed, however, a system can be simplified so that the overall volume of the circuit system can be reduced. Such bidirectional converters include insulation-type converters employing a transformer between input and output, and non-insulation-type converters without employing a transformer. Such insulation-type converters are used when the input and output currents should be electrically insulated or when a high voltage conversion ratio is necessary. However, due to the size and cost of the transformer, such insulation-type converters are frequently used for large and medium output voltage applications. Non-insulation-type converters are not able to achieve electrical insulation and a high step-up/step-down ratio, but are advantageous in that such converters are able to be implemented at low cost and have a simple circuit configuration, such that they are frequently used for small and medium power applications handling power levels below 60 V. [0004] At present, applications of bidirectional DC-DC converters are gradually increasing, and such converters are being adopted for use in devices such as battery chargers, uninterruptible DC power supplies (UPS), electric motors for electric automobiles and the like. RELATED ART DOCUMENT [0005] (Patent Document 1) Korean Patent Laid-open Publication No. 2012-0048154 SUMMARY [0006] An aspect of the present disclosure may provide a power supply device capable of stepping up and stepping down an input voltage with high efficiency. [0007] An aspect of the present disclosure may also provide a power supply device capable of reducing switching loss and conduction loss in a switching element. [0008] An aspect of the present disclosure may also provide a power supply device capable of improving efficiency of a circuit system by reducing inductor ripple currents and capacitor ripple voltages. [0009] According to an aspect of the present disclosure, a power supply device may include: a Single-Ended Primary-Inductor Converter (SEPIC) or a Zeta converter having an energy storage unit; and a power transmitting unit transmitting the energy stored in an energy storage unit of the SEPIC/Zeta converter to a load stage. [0010] The SEPIC/Zeta converter may include: a first inductor connected between a first node and a second node; a first switch connected between the second node and a ground so as to be switched according to a first switching signal; a separation capacitor connected between the second node and a third node; a second inductor connected between the third node and the ground; and a second switch connected between the third node and a fourth node. [0011] The power supply device may further include: an input capacitor connected between the first node and the ground; and an output capacitor connected between the fourth node and the ground. [0012] The power transmitting unit may be connected between the second node and the fourth node. [0013] The power transmitting unit may include a third switch, a fourth switch, and an auxiliary inductor connected in series. [0014] According to another aspect of the present disclosure, a power supply device may include: a first inductor connected between a first node and a second node; a first switch connected between the second node and a ground so as to be switched according to a first switching signal; a separation capacitor connected between the second node and a third node; a second inductor connected between the third node and the ground; a second switch connected between the third node and a fourth node; and a power transmitting unit disposed between the second node and the fourth node so as to provide a power transmission path. [0015] The power supply device may further include: an input capacitor connected between the first node and the ground; and an output capacitor connected between the fourth node and the ground potential. [0016] The power transmitting unit may be connected between the second node and the fourth node. [0017] The power transmitting unit may include a third switch, a fourth switch, and an auxiliary inductor connected in series. [0018] A power input unit may be connected between the first node and the ground; and a load may be connected between the fourth node and the ground. [0019] A load may be connected between the first node and the ground; and a power input unit may be connected between the fourth node and the ground. BRIEF DESCRIPTION OF DRAWINGS [0020] The above and other aspects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: [0021] FIG. 1 is a circuit diagram of a power supply device according to an exemplary embodiment of the present disclosure; [0022] FIG. 2 is a circuit diagram of a power supply device according to another exemplary embodiment of the present disclosure; [0023] FIG. 3 is a circuit diagram of a simulation test circuit for the power supply device shown in FIG. 1 ; [0024] FIG. 4 shows waveforms of parts of the circuit shown in FIG. 3 ; [0025] FIG. 5 is a circuit diagram of a simulation test circuit for the power supply device shown in FIG. 1 and [0026] FIG. 6 shows waveforms of parts of the circuit shown in FIG. 5 . DETAILED DESCRIPTION [0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Throughout the drawings, the same or like reference numerals will be used to designate the same or like elements. [0028] FIG. 1 is a circuit diagram of a power supply device according to an exemplary embodiment of the present disclosure. [0029] Referring to FIG. 1 , the power supply device 100 may include an input voltage source Vi, a power converting unit 110 , and a direct power transmitting unit 120 . [0030] The power converting unit 110 may employ a Single-Ended Primary-Inductor Converter SEPIC/Zeta (known as the inverted SEPIC) topology. [0031] The SEPIC converter and the Zeta converter may step up as well as step down an input voltage. [0032] The SEPIC/Zeta converter may operate as a SEPIC converter in one direction and may operate a Zeta converter in the other direction. [0033] That is, by replacing a diode element with an active switching element in existing SEPIC converters and Zeta converters and by configuring a circuit as shown in FIG. 1 , it may be possible to provide a SEPIC/Zeta converter that operates as a SEPIC converter in the direction as indicated by the arrow at the left side of FIG. 1 and operates as a Zeta converter in the direction as indicated by the arrow on the right of FIG. 1 . That is, the power converting unit 110 may operate as a direct current (DC) to DC converter, operable to step up and step down an input voltage bi-directionally. [0034] The power supply device 100 according to an exemplary embodiment of the present disclosure may operate as a bidirectional SEPIC/Zeta converter. The power supply device 100 according to an exemplary embodiment of the present disclosure may operate as a SEPIC converter in one direction and may operate as a Zeta converter in the other direction. [0035] For convenience of explanation, an example in which the power supply device according to an exemplary embodiment of the present disclosure operates as a SEPIC converter will be described. [0036] The input voltage source Vi may be connected between a first node N 1 of the power converting unit 110 and the ground. The input voltage source Vi may supply an input voltage at a certain level to the power converting unit 110 and may be a wall concent or a battery. [0037] The power converting unit 110 may include an input capacitor Ci, a first inductor L 1 , a first switching element S 1 , a separation capacitor Cs, a second inductor L 2 , a second switching element S 2 , and an output capacitor Co. [0038] The input capacitor Ci may be connected between the first node N 1 and the ground. The input capacitor Ci may store a voltage supplied from the input voltage source Vi according to the switching of a first switching element S 1 and may release the stored energy. [0039] The first inductor L 1 may be connected between the first node N 1 and the second node N 2 . That is, one terminal of the first inductor L 1 may be connected to the first node N 1 , and the other terminal thereof may be connected to one terminal of the separation capacitor Cs through the second node N 2 . The first inductor L 1 may store the energy supplied from the input voltage source Vi and/or the input capacitor Ci according to the switching of the first switching element S 1 and may release the stored energy. [0040] The first switching element S 1 may be switched according to a first switching signal with a predetermined on-duty cycle supplied from an external duty control unit (not shown) so as to control the current flowing in the power converting unit 110 . To this end, the first switching element S 1 may include a gate terminal to which the first switching signal is input, a drain terminal connected to the second node N 2 , and a source terminal connected to the ground. The first switching element S 1 may include a field effect transistor (FET), an insulated gate bipolar transistor (IGBT), and an integrated gate commutated thyristor (IGCT). [0041] The first switching element S 1 may further include an internal diode that is forward biased in the direction from the source terminal to the drain terminal. [0042] The separation capacitor Cs may be connected between the second node N 2 and the third node N 3 . That is, one terminal of the separation capacitor Cs may be connected to the second node N 2 and the other terminal thereof may be connected to the third node N 3 . The separation capacitor Cs may store energy according to the switching of the first switching element S 1 and may release the stored energy to a load. [0043] The second inductor L 2 may be connected between the third node N 3 and the ground. That is, one terminal of the second inductor L 2 may be connected to the third node N 3 and the other terminal thereof may be connected to the ground. The second inductor L 2 may store energy according to the switching of the first switching element S 1 and may release the stored energy to the load or to the separation capacitor Cs to charge it with the energy. [0044] The second switching element S 2 may be switched according to a second switching signal with a predetermined on-duty cycle supplied from an external duty control unit (not shown) so as to control the current flowing in the power converting unit 110 . To this end, the second switching element S 2 may include a gate terminal to which the second switching signal is input, a drain terminal connected to the third node N 3 , and a source terminal connected to a fourth node N 4 . The second switching element S 2 may include a field effect transistor (FET), an insulated gate bipolar transistor (IGBT), and an integrated gate commutated thyristor (IGCT). [0045] The second switching element S 2 may further include an internal diode that is forward biased in the direction from the source terminal to the drain terminal. [0046] The internal diode disposed in the second switching element S 2 may be connected between the third node N 3 and the fourth node N 4 . That is, the anode terminal of the internal diode may be connected to the third node N 3 and the cathode terminal thereof may be connected to the fourth node N 4 . The internal diode may become conductive depending on the potential difference between the third node N 3 and the fourth node N 4 so as to transmit the energy stored in the first and second inductors L 1 and L 2 to the fourth node N 4 . In addition, the internal diode may block the reverse current flowing from the fourth node N 4 toward the third node N 3 . [0047] The output capacitor Co may be connected between the fourth node N 4 and the ground. That is, one terminal of the output capacitor Co may be connected to the fourth node N 4 and the other terminal thereof may be connected to the ground. The capacitor may smooth the voltage output to the load through the fourth node N 4 flat and store it when the first switching element S 1 is switched on, and may output the stored voltage to the load through the fourth node N 4 when the first switching element S 1 is switched off. The load may include a light emitting diode (LED), a light emitting diode array (LED array), a back light unit, various types of information devices, or a display device. [0048] The power converting unit 110 may charge the first inductor L 1 while charging the second inductor L 2 by releasing the energy stored in the separation capacitor Cs when the first switching element S 1 is switched on according to the first switching signal, and may release the energy stored in the first and second inductors L 1 and L 2 to the fourth node N 4 while charging the output capacitor Co when the first switching element S 1 is switched off according to the first switching signal. [0049] The power transmitting unit 120 may create an additional power transmission path. [0050] The power transmitting unit 120 may include a third switch S 3 , a fourth switch S 4 , and an auxiliary inductor element La. [0051] The third switch S 3 , the fourth switch S 4 and the auxiliary inductor element La may be connected in series. [0052] One terminal of the third switch S 3 may be connected to the second node N 2 . One terminal of the auxiliary inductor element La may be connected to the fourth node N 4 . [0053] The third switching element S 3 may further include an internal diode that is forward biased in the direction from the source terminal to the drain terminal. The fourth switching element S 4 may further include an internal diode that is forward biased in the direction from the source terminal to the drain terminal. [0054] The drain terminal of the third switching element S 3 and the drain terminal of the fourth switching element S 4 may be connected to each other. [0055] The third and fourth switching elements S 3 and S 4 may supply the current supplied through the second node N 2 to the auxiliary inductor element La. [0056] The auxiliary inductor element La may store the energy supplied according to the switching of the third switching element S 3 and the fourth switching element S 4 so as to reduce the level of current flowing the first switching element S 1 and the switching loss, such that the first switching element S 1 is soft switched. [0057] The power transmitting unit 120 may soft switch the third switching element and the fourth switching element after the first switching element S 1 is switched off and thereby create a power path from the first inductor L 1 to the fourth node N 4 through an auxiliary inductor element La by itself, so as to output by itself to the fourth node N 4 the substantial amount of power that has no switching loss and is directly transmitted with high efficiency. [0058] Further, the power transmitting unit 120 may linearly increase the current flowing through the first switching element S 1 slowly by using the current characteristic of the auxiliary inductor element La when the first switching element S 1 is switched on and thereby soft switching the first switching element S 1 , such that turn-on loss in the first switching element S 1 and turn-off loss in the third and fourth switching elements S 3 and S 4 may be eliminated. [0059] Furthermore, the power transmitting unit 120 may linearly increase the current flowing through the third and fourth switching element S 3 and S 4 so as to slowly linearly decrease the current flowing through the second switching element S 2 by using the current characteristic of the auxiliary inductor element La when the path via the second switch is blocked, such that the turn-off loss in the second switching element S 2 and the turn-on loss in the third and fourth switching elements are eliminated. [0060] That is, the power supply device according to an exemplary embodiment of the present disclosure may create by itself the current path from the first inductor L 1 to the fourth node N 4 through the power transmitting unit 120 so as to output by itself to a load the substantial amount of power via the auxiliary inductor element La with no switching loss, while outputting the amount of power necessary for converting the rest of voltage and current via the power converting unit 110 . [0061] As a result, the power supply device 100 according to an exemplary embodiment of the present disclosure may reduce power loss in each of the switching elements through the power transmitting unit 120 , thereby improving DC-DC conversion efficiency. [0062] Thus far, an example in which the power supply device according to an exemplary embodiment of the present disclosure operates as a SEPIC converter has been described. It will be apparent to those skilled in the art that the power supply device may operate as a Zeta converter by switching positions of the power input unit and the load, and thus a detailed description thereof will not be made. [0063] That is, if the power supply device according to an exemplary embodiment of the present disclosure operates as a Zeta converter, a load is connected between the first node and the ground, and a power input unit may be connected between the fourth node and the ground. [0064] Further, if the power supply device according to an exemplary embodiment of the present disclosure operates as a Zeta converter, the second switching element S 2 may perform the function of the first switching element S 1 instead. [0065] The additional transmission path created by the power transmitting unit 120 may perform direct power transmission between input and output. [0066] Here, when the power supply device operates as a SEPIC converter, the conversion ratio of output to input may be expressed as Vo/Vi=(1−D2)/(1−D1). In addition, when the power supply device operates as a Zeta converter, the conversion ratio of output to input may be expressed as Vo/Vi=(1−D1)/(1−D2). [0067] Where D1 denotes the conduction ratio of the first switch S 1 , and D2 denotes the conduction ratio of the second switch S 2 . [0068] As such, the power supply device according to an exemplary embodiment of the present disclosure may be operable to step up and step down an input voltage, unlike existing bidirectional converters. For instance, an input voltage is between 10 V and 20 V and an output voltage is between 10 V and 20 V, the power supply device according to an exemplary embodiment of the present disclosure may be used even if the range of the input and output voltages overlap. [0069] Further, in the power supply device according to an exemplary embodiment of the present disclosure, when power is transmitted via the additional power transmission path, the voltages applied to the first inductor L 1 and the second inductor L 2 are reduced to Vi-Vo, so that ripple currents are reduced. If the ripple currents are reduced, the rms current in the circuit is reduced, so that inductor DC resistance loss and capacitor serial resistance loss may be reduced, thereby increasing efficiency. That is, efficiency may be increased as the time in which power is transmitted via the additional power transmission path is increased. [0070] Further, the auxiliary inductor La on the additional power transmission path may derive soft current commutation between switching elements, thereby allowing zero current switching (ZCS). [0071] In addition, the power supply device according to an exemplary embodiment of the present disclosure replaces existing diodes with active switches to allow zero voltage switching (ZVS), thereby reducing switching conduction loss. [0072] In addition, if a switch is switched on or off while an internal diode included in a switching element is conductive, zero voltage switching may be made. [0073] FIG. 2 is a circuit diagram of a power supply device according to another exemplary embodiment of the present disclosure. [0074] Since the configuration of the power converting unit is the same as that of the power supply device according to the exemplary embodiment described above, a detailed description thereof will be omitted. [0075] The power transmitting unit 120 may have two power transmission paths. That is, a diode element, a third switching element S 3 , and an auxiliary inductor element La may create a power transmission path for a SEPIC converter mode. The diode element, the third switching element S 3 , and the auxiliary inductor element La may be connected in series between a second node N 2 and a fourth node N 4 . [0076] In addition, a diode element, a fourth switching element S 4 , and the auxiliary inductor element La may create a power transmission path for a Zeta converter mode. The diode element, the fourth switching element S 4 , and the auxiliary inductor element La may be connected in series between the second node N 2 and the fourth node N 4 . [0077] FIG. 3 is a circuit diagram of a simulation test circuit for the power supply device shown in FIG. 1 . FIG. 3 shows a SEPIC converter mode. FIG. 4 shows waveforms of parts of the circuit shown in FIG. 3 . [0078] Referring to FIG. 4 , it can be seen that inductor ripple currents are reduced by virtue of the additional power transmission path. [0079] Further, ZCS and ZVS of the switching elements may be seen by soft current commutation of the auxiliary inductor La and appropriate switch control. [0080] That is, it can be seen that the switching element Q 1 may be switched on with zero current. Further, it can be seen that the switching element Q 2 may be switched on or off with zero-voltage. [0081] Further, it can be seen that the internal diode DQ 2 in the switching element Q 2 may be switched off with zero-current. Further, it can be seen that the internal diode DQ 3 in the switching element Q 3 may be switched on or off with zero-current. [0082] Further, it can be seen that the switching elements Q 3 and Q 4 may be switched on or off with zero-current. [0083] Further, it can be seen that the switching elements Q 2 and Q 3 are also switched with zero-voltage. [0084] FIG. 5 is a circuit diagram of a simulation test circuit for the power supply device shown in FIG. 1 . FIG. 5 shows a Zeta converter mode. FIG. 6 shows waveforms of parts of the circuit shown in FIG. 5 . [0085] Referring to FIG. 6 , it can be seen that inductor ripple currents are reduced by virtue of the additional power transmission path. [0086] Further, ZCS and ZVS of the switching elements can be seen by soft current commutation of the auxiliary inductor La and appropriate switch control. [0087] That is, it can be seen that the switching element Q 5 may be zero current switched when it is switched on. Further, it can be seen that the switching element Q 6 may be zero-voltage-switched when it is switched on or off. [0088] Further, it can be seen that the internal diode DQ 6 in the switching element Q 6 may be zero-current-switched when it is switched off. Further, it can be seen that the internal diode DQ 7 in the switching element Q 7 may be zero-current-switched when it is switched on or off. [0089] Further, it can be seen that the switching elements Q 7 and Q 8 may be zero-current-switched when it is switched on or off. [0090] Further, it can be seen that the switching elements Q 6 and Q 7 are also zero-voltage switched. [0091] As set forth above, according to exemplary embodiments of the present disclosure, a power supply device capable of stepping up and stepping down an input voltage with high efficiency may be provided. [0092] Further, according to exemplary embodiments of the present disclosure, a power supply device capable of reducing switching loss and conduction loss in a switching element may be provided. [0093] Moreover, according to exemplary embodiments of the present disclosure, a power supply device capable of improving efficiency of a circuit system by reducing inductor ripple currents and capacitor ripple voltages may be provided. [0094] While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the spirit and scope of the present disclosure as defined by the appended claims.

There is provided a power supply device including: a SEPIC/Zeta converter having an energy storage unit; and a power transmitting unit transmitting the energy stored in the SEPIC/Zeta converter to a load stage.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a memory, and more particularly to the layout and the structure of a NAND flash memory. [0003] 2. Description of the Prior Art [0004] Recently, as demands for the portable electronic devices are increasing, the market for the flash memory and the electrically erasable programmable read-only memory (EEPROM) is also expanding as well. The aforesaid portable electronic device includes the storage memory for the digital camera, the cell phones, the video game apparatuses, PDAs, telephone answering machines, and the programmable ICs, etc. A flash memory belongs to a non-volatile memory, and has an important characteristic of being able to store data in the memory even though the power is turned off. By changing the threshold voltage of the transistor, the gate can be turned on and off, and the data can be stored in the transistor. Generally speaking, the flash memory can be divided into two types of configurations, namely, a NOR flash memory and a NAND flash memory. The drains of memory cells of a NOR flash memory are connected in parallel for a faster reading speed, which is suitable for code flash memory mainly used for executing program codes. The drains and sources of two neighboring memory cells of a NAND flash memory are serially connected for integrating more memory cells per unit area, which is suitable for a data flash memory mainly used for data storage. Both of the NOR flash memory and the NAND flash memory have a MOS-like memory cell structure, so as to provide advantages of smaller size, higher operation speed, and higher density. [0005] As the electronic device becomes smaller, integration of the flash memory needs to be increased. Therefore, it is an object of the present invention to provide a new layout and structure for the flash memory to increase the integration of the flash memory. The layout design according to the present invention can make the size of the flash memory smaller. SUMMARY OF THE INVENTION [0006] According to the flash memory disclosed in the present invention, the flash memory comprises a substrate; a first active area positioned in the substrate, wherein the first active area comprises a first memory cell string comprising a plurality of first storage transistors, a first select gate transistor comprising a first gate length, and a second select gate transistor comprising a second gate length, wherein the first select gate transistor further comprises a first horizontal channel, and the second select gate transistor further comprises a first recessed channel, and wherein each of the first storage transistors comprises a third gate length, respectively; and a second active area positioned in the substrate, wherein the second active area comprises a second memory cell string comprising a plurality of second storage transistors, a third select gate transistor comprising a fourth gate length, and a fourth select gate transistor comprising a fifth gate length, wherein the third select gate transistor further comprises a second recessed channel, and the fourth select gate transistor further comprises a second horizontal channel, and wherein each of the second storage transistors comprises a sixth gate length, respectively, wherein the first select gate transistor and the third select gate transistor are arranged in the same column, and the second select gate transistor and the fourth select gate transistor are arranged in the same column. [0007] According to a preferred embodiment of the present invention, the length of the first gate length, the length of the second gate length, the length of the third gate length, the length of the fourth gate length, the length of the fifth gate length, and the length of the sixth gate length are substantially equal. [0008] The select gate transistor of the present invention includes a recessed channel, which can provide a larger process window, and integration of the elements can be increased due to the recessed channel as well. [0009] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 shows a schematic layout of a NAND type flash memory according to the present invention. [0011] FIG. 2 a shows a sectional view as viewed along the active area 54 in FIG. 1 according to the NAND type flash memory of the present invention. [0012] FIG. 2 b shows a sectional view as viewed along the active area 68 in FIG. 1 according to the NAND type flash memory of the present invention. [0013] FIG. 2 c shows a sectional view as viewed along the active area 80 in FIG. 1 according to the NAND type flash memory of the present invention. [0014] FIG. 2 d shows a sectional view as viewed along the active area 92 in FIG. 1 according to the NAND type flash memory of the present invention. [0015] FIG. 3 to FIG. 5 show the operating method of the NAND type flash memory according to the present invention. DETAILED DESCRIPTION [0016] The structure of the NAND type flash memory disclosed in the present invention features a structure of a plurality of dual gate transistors (dual SG), which is meant to have two ends of the memory cell strings connected to two select gate transistors in series, respectively. In addition, every storage transistor positioned in the memory cell strings is a two-bit storage transistor. [0017] FIG. 1 shows a schematic layout of a NAND type flash memory according to the present invention. As shown in FIG. 1 , a NAND type flash memory 50 comprises: a substrate 52 , a plurality of active areas 54 , 66 , 78 , 90 positioned in the substrate 52 , wherein the active area 54 comprises a plurality of select gate transistors 58 , 60 , a memory cell string 56 , and a plurality of select gate transistors 62 , 64 , and wherein the select gate transistors 58 , 60 , the memory cell string 56 , and the select gate transistors 62 , 64 are positioned in a same row. In addition, the select gate transistor 58 is coupled to the select gate transistor 60 in series, and the select gate transistor 62 is coupled to the select gate transistor 64 in series. [0018] Furthermore, the memory cell string 56 comprises a plurality of two-bit storage transistors, such as the two-bit storage transistors 114 , 116 ; and the two-bit storage transistors 114 , 116 comprise a gate length L 1 . In addition, the select gate transistors 60 , 62 comprise a recessed channel (not shown), and the select gate transistors 58 , 64 comprise a horizontal channel (not shown). Each of the select gate transistors 58 , 60 , 62 , 64 comprises a gate length L 2 . [0019] The active area 66 comprises a plurality of select gate transistors 70 , 72 , a memory cell string 68 , and a plurality of select gate transistors 74 , 76 , and wherein the select gate transistors 70 , 72 , a memory cell string 68 , and the select gate transistors 74 , 76 are positioned in a same row. In addition, the select gate transistor 70 is coupled to the select gate transistor 72 in series, and the select gate transistor 74 is coupled to the select gate transistor 76 in series. [0020] Furthermore, the memory cell string 68 comprises a plurality of two-bit storage transistors, such as the two-bit storage transistors 118 , 120 ; and the two-bit storage transistors 118 , 120 comprise a gate length L 1 . In addition, the select gate transistors 70 , 76 comprise a recessed channel (not shown), and the select gate transistors 72 , 74 comprise a horizontal channel (not shown). Each of the select gate transistors 70 , 72 , 74 , 76 comprises a gate length L 2 . [0021] The active area 78 comprises a plurality of select gate transistors 82 , 84 , a memory cell string 80 , and a plurality of select gate transistors 86 , 88 , and wherein the select gate transistors 82 , 84 , a memory cell string 80 , and the select gate transistors 86 , 88 are arranged in a same row. In addition, the select gate transistor 82 is coupled to the select gate transistor 84 in series, and the select gate transistor 86 is coupled to the select gate transistor 88 in series. Furthermore, the memory cell string 80 comprises a plurality of two-bit storage transistors, such as the two-bit storage transistors 122 , 124 ; and the two-bit storage transistors 122 , 124 comprise a gate length L 1 . In addition, the select gate transistors 84 , 86 comprise a recessed channel (not shown), and the select gate transistors 82 , 88 comprise a horizontal channel (not shown). Each of the select gate transistors 82 , 84 , 86 , 88 comprises a gate length L 2 . [0022] Furthermore, the active area 90 comprises a plurality of select gate transistors 94 , 96 , a memory cell string 92 , and a plurality of select gate transistors 98 , 100 , and wherein the select gate transistors 94 , 96 , the memory cell string 92 , and the select gate transistors 98 , 100 are arranged in a same row. In addition, the select gate transistor 94 is coupled to the select gate transistor 96 in series, and the select gate transistor 98 is coupled to the select gate transistor 100 in series. Furthermore, the memory cell string 92 comprises a plurality of two-bit storage transistors, such as the two-bit storage transistors 126 , 128 ; and the two-bit storage transistors 126 , 128 comprise a gate length L 1 . In addition, the select gate transistors 94 , 100 comprise a recessed channel (not shown), and the select gate transistors 96 , 98 comprise a horizontal channel (not shown). Each of the select gate transistors 94 , 96 , 98 , 100 comprises a gate length L 2 . [0023] According to the preferred embodiment of the present invention, the length of the gate length L 1 can be equal to the length of the gate length L 2 , but is not limited to this limitation; the length of the gate length L 1 and the length of the gate length L 2 can be different as well. In addition, the select gate transistors 58 , 64 , 72 , 74 , 82 , 88 , 96 , 98 comprising a horizontal channel is always remained at depletion mode during operation, which means that the select gate transistors 58 , 64 , 72 , 74 , 82 , 88 , 96 , 98 are always turned on during operation. [0024] Additionally, the select gate transistors 58 , 70 , 82 , 94 arranged in a same column are coupled to each other in sequence electrically through a gate conductor 102 . The select gate transistors 60 , 72 , 84 , 96 positioned in a same column are coupled to each other in sequence electrically through a gate conductor 104 . The select gate transistors 62 , 74 , 88 , 98 positioned in a same column are coupled to each other in sequence electrically through a gate conductor 106 . The select gate transistors 64 , 76 , 88 , 100 positioned in a same column are coupled to each other in sequence electrically through a gate conductor 108 . In addition, a plurality of bit-line contact pads 110 , 112 are positioned at a side of the gate conductors 102 , 108 respectively to send the bit-line signals. [0025] Because the select gate transistors of the present invention comprise a recessed channel, a larger window process can be obtain during the STI formation, and the integration of the elements can be increased as well. For example, the width of the gate conductor can shrink to 0.09 μm, and the space of the gate conductor can shrink to 0.09 μm. Therefore, the space which the gate conductor has occupied according to the present invention is smaller than the space which the gate conductor occupied according to the conventional process. [0026] FIG. 2 a shows a sectional view as viewed along the active area 54 in FIG. 1 according to the NAND type flash memory of the present invention. [0027] As shown in FIG. 2 a , the flash memory 50 comprises a substrate 52 , a memory cell string 56 positioned on the substrate 52 , a select gate transistor 60 comprising a recessed channel and a gate length L 2 , a select gate transistor 58 comprising a horizontal channel and a gate length L 2 , a select gate transistor 62 comprising a recessed channel and a gate length L 2 , and a select gate transistor 64 comprising a horizontal channel and a gate length L 2 . In addition, the memory cell string 56 comprises a plurality of two-bit storage transistors, such as the two-bit storage transistors 114 , 116 comprising a gate length L 1 , wherein the number of the two-bit storage transistors comprised in the memory cell string 56 can be 16 or 32, and all of the two-bit storage transistors may be PMOS transistors. [0028] Furthermore, the select gate transistor 60 is connected directly to one end of the memory cell string 56 in series, and the select gate transistor 58 is connected directly to the select gate transistor 60 in series. The select gate transistor 62 is connected directly to another end of the memory cell string 56 in series, and the select gate transistor 64 is connected directly to the select gate transistor 62 in series. [0029] According to a preferred embodiment of the present invention, the select gate transistors 58 , 64 comprising a horizontal channel are always in a depletion mode, which means that the select gate transistors 58 , 64 are always turned on during operation. [0030] FIG. 2 b shows a sectional view as viewed along the active area 66 in FIG. 1 according to the NAND type flash memory of the present invention. As shown in FIG. 2 b , the flash memory 50 comprises a substrate 52 , a memory cell string 68 positioned on the substrate 52 , a select gate transistor 72 comprising a horizontal channel and a gate length L 2 , a select gate transistor 70 comprising a recessed channel and a gate length L 2 , a select gate transistor 74 comprising a horizontal channel and a gate length L 2 , and a select gate transistor 76 comprising a recessed channel and a gate length L 2 . In addition, the memory cell string 68 comprises a plurality of two-bit storage transistors, such as the two-bit storage transistors 118 , 120 , which comprise a gate length L 1 , wherein the number of the two-bit storage transistors comprised in the memory cell string 68 can be 16 or 32, and all of the two-bit storage transistors may be PMOS transistors. Furthermore, the select gate transistor 72 is connected directly to one end of the memory cell string 68 in series, and the select gate transistor 70 is connected directly to the select gate transistor 72 in series. The select gate transistor 74 is connected directly to another end of the memory cell string 68 in series, and the select gate transistor 76 is connected directly to the select gate transistor 74 in series. [0031] According to a preferred embodiment of the present invention, the select gate transistors 72 , 74 comprising a horizontal channel are always in a depletion mode, which means that the select gate transistors 72 , 74 are always turned on during operation. [0032] FIG. 2 c shows a sectional view as viewed along the active area 78 in FIG. 1 according to the NAND type flash memory of the present invention. As shown in FIG. 2 c , the flash memory 50 comprises a substrate 52 , a memory cell string 80 positioned on the substrate 52 , a select gate transistor 84 comprising a recessed channel and a gate length L 2 , a select gate transistor 82 comprising a horizontal channel and a gate length L 2 , a select gate transistor 86 comprising a recessed channel and a gate length L 2 , and a select gate transistor 88 comprising a horizontal channel and a gate length L 2 . In addition, the memory cell string 80 comprises a plurality of two-bit storage transistors, such as the two-bit storage transistors 122 , 124 comprising a gate length L 1 , wherein the number of the two-bit storage transistors comprised in the memory cell string 80 can be 16 or 32, and all of the two-bit storage transistors may be PMOS transistors. Furthermore, the select gate transistor 84 is connected directly to one end of the memory cell string 80 in series, and the select gate transistor 82 is connected directly to the select gate transistor 84 in series. The select gate transistor 84 is connected directly to another end of the memory cell string 80 in series, and the select gate transistor 88 is connected directly to the select gate transistor 86 in series. [0033] According to a preferred embodiment of the present invention, the select gate transistors 82 , 88 comprising a horizontal channel are always in a depletion mode, which means that the select gate transistors 82 , 88 are always turned on during operation. [0034] FIG. 2 d shows a sectional view as viewed along the active area 92 in FIG. 1 according to the NAND type flash memory of the present invention. As shown in FIG. 2 d , the flash memory 50 comprises a substrate 52 , a memory cell string 92 positioned on the substrate 52 , a select gate transistor 96 comprising a horizontal channel and a gate length L 2 , a select gate transistor 94 comprising a recessed channel and a gate length L 2 , a select gate transistor 98 comprising a horizontal channel and a gate length L 2 , and a select gate transistor 100 comprising a recessed channel and a gate length L 2 . In addition, the memory cell string 92 comprises a plurality of two-bit storage transistors, such as the two-bit storage transistors 126 , 128 , which comprise a gate length L 1 , wherein the number of the two-bit storage transistors comprised in the memory cell string 92 can be 16 or 32, and all of the two-bit storage transistors may be PMOS transistors. Furthermore, the select gate transistor 96 is connected directly to one end of the memory cell string 92 in series, and the select gate transistor 94 is connected directly to the select gate transistor 96 in series. The select gate transistor 98 is connected directly to another end of the memory cell string 92 in series, and the select gate transistor 100 is connected directly to the select gate transistor 98 in series. According to a preferred embodiment of the present invention, the select gate transistors 96 , 98 comprising a horizontal channel are always in a depletion mode, which means that the select gate transistors 96 , 98 are always turned on during operation. [0035] FIG. 3 to FIG. 5 show the operating method of the NAND type flash memory according to the present invention. [0036] FIG. 3 shows the operating method in which the memory cell strings 68 , 92 are read simultaneously. [0037] First, the select gate transistor having the symbol “◯” depicted on it means that the select gate transistor is turned on, and the select gate transistor having the symbol “X” depicted on it means that the select gate transistor is turned off. [0038] As shown in FIG. 3 , the gate conductors 102 , 108 are turned off, the gate conductors 104 , 106 are turned on, 1 volt is applied to the memory cell strings 56 , 68 , 80 , 92 , 0 volt is applied to the bit-line contact pad 110 , 2.5 volts is applied to the bit-line contact pad 112 , and 0 volt is applied to the substrate 52 (not shown). [0039] Notably, the select gate transistors 58 , 64 , 72 , 74 , 82 , 88 , 96 , 98 are always turned on, because they are in the depletion mode. Therefore, the turning on and off of the gate conductors 102 , 104 , 106 , 108 are to only control the on and off of the select gate transistors 76 , 84 , 86 , 94 , 100 . In this way, the data stored in the memory cell strings 68 , 92 can be read. [0040] In FIG. 4 and FIG. 5 , the select gate transistor having the symbol “◯” depicted on it means that the select gate transistor is turned on, and the select gate transistor having the symbol “X” depicted on it means that the select gate transistor is turned off. [0041] FIG. 4 shows the operating method in which memory cell strings 68 , 92 are programmed. As shown in FIG. 4 , the gate conductors 102 , 108 are turned off, the gate conductors 104 , 106 are turned on, 6 volts is applied to memory cell strings 56 , 68 , 80 , 92 , −3 volts is applied to the bit-line contact pad 112 , 0 volt (not shown) is applied to the substrate 52 , and the bit-line contact pad 110 is floating. In this way, data can be programmed into the two-bit storage transistors 114 , 116 , 126 , 128 which are comprised in the memory cell strings 68 , 92 , respectively. [0042] FIG. 5 shows the operating method in which the memory cell strings 56 , 68 , 80 , 92 are block erased. As shown in FIG. 5 , all of the gate conductors 102 , 104 , 106 , 108 are turned on, −7 volts is applied to the memory cell strings 56 , 68 , 80 , 92 , 8 volts is applied to the bit-line contact pad 112 , 8 volts is applied to the bit-line contact pad 110 , and 8 volts (not shown) is applied to the substrate 52 . In this way, data stored in the memory cell strings 56 , 68 , 80 , 92 can be block erased. [0043] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.

A flash memory is provided. The flash memory features of having the select gate transistors to include two different channel structures, which are a recessed channel structure and a horizontal channel. Because of the design of the recessed channel structure, the space between the gate conductor lines, which are for interconnecting the select gates of the select gate transistors arranged on the same column, can be shortened. Therefore, the integration of the flash memory can be increased; and the process window of the STI process can be increased as well. In addition, at least one depletion-mode select gate transistor is at one side of the memory cell string. The select gate transistor of the depletion-mode is always turned on.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slip casting forming method and mold in and with which the slip of refractory powders, for example, ceramic powders, metallic powders or carbon powders is cast to produce a cast article (green body), and more particularly to a forming method and mold which are well suited to produce a cast article of complicated shape. 2. Description of the Prior Art In case of forming, by slip casting, a hollow molding whose cavity portion has a complicated shape, that is, a molding which requires a core of complicated shape not extractible due to an inverse gradient, the removal of the core has been difficult or impossible with a conventional gypsum mold. A prior art method pertinent to the present invention is disclosed in British Pat. No. 1482436. This method consists in that a mold is made of an organic material soluble in a solvent for a part of complicated shape, while a gypsum mold is used for a part of simple shape, and that both the molds are assembled into a desired mold. This method, however, does not take it into consideration that depending upon the geometries of a cast article, a green body (a cast article) involves a difference in density between the organic part and the gypsum part, to affect the reliability of the strength of the sintering body or to affect the dimensional accuracy of the sintering body or the job efficiency of the fabrication thereof. OBJECT OF THE INVENTION In view of the above, the present invention has for its object to provide a slip casting mold with which a core or a mold is readily removed even in a case where a cast article of complicated shape, namely, a cast article requiring the core or the mold of complicated shape, is formed by slip casting. SUMMARY OF THE INVENTION The present invention consists in a forming method in which a slip containing water is cast into a mold and the mold is removed after the hardening of the slip, characterized in that the mold is made by the use of a water-soluble binder. The present invention consists in a mold into which a slip containing water is cast and which is removed after the hardening of the slip, characterized by being made by the use of a binder soluble in water at room temperature. The bone material of a mold to be used is powders insoluble or hardly soluble in the water of the slip, for example, the powders of alumina (Al 2 O 3 ), magnesia (MgZO), zircon sand, or silica sand. The water-soluble binder to be used is a carbonate such as sodium carbonate (Na 2 CO 3 ) or potassium carbonate (K 2 CO 3 O; a chloride such as sodium chloride (NaCl), potassium chloride (KCl), magnesium chloride (MgCl 2 ) or lithium chloride (LiCl); a phosphate such as trisodium phosphate (Na 3 PO 4 ), tripotassium phosphate (K 3 PO 4 ) or dipotassium hydrogen phosphate (K 2 HPO 4 ); or a sulfate such as sodium hydrogen sulfate (NaHSO 4 ), potassium hydrogen sulfate (KHSO 4 ), ammonium sulfate ((NH 4 ) 2 SO 4 ), magnesium sulfate (MgSO 4 ), sodium sulfate (Na 2 SO 4 ), potassium sulfate (K 2 SO 4 ), lithium sulfate (LiSO 4 ) or aluminum sulfate (Al 2 (SO 4 ) 3 ). The mixing ratio of the bone material of a mold, the binder and water should preferably be set at the bone material of a mold: 50-95 weight-% and the binder and water: 5-50 weight-% from the aspects of the strength and economy of the mold. With increase in the quantity of addition of the binder, the mold strength is stabilized more, and the stability of a mold surface is enhanced more, so that the handling of the mold is facilitated more. However, an unnecessarily high strength is not desired in the present invention which is intended to lower the mold strength owing to the absorption of water from the slip. When the binder is added in excess, the roughness of the surface of the mold is noted at a drying step, and hence, a quantity of addition exceeding 47 weight-% is unfavorable. On the other hand, the binder in an amount less than 2 weight-% is not practical because of an insufficient mold strength. Meanwhile, the quantity of addition of the water contents affects the job efficiency of the mold fabricating operation and the stability of the mold surface. Especially when the water content is less than 3 weight-% with respect to the total weight including the bone material of a mold, the fabrication of the mold becomes difficult. Accordingly, the aforementioned value of 5-50 weight-% based on the total weight is proper for the sum of the binder and the water. Besides, while a thin-walled mold can be broken down by only the water content of the slip, a thick-walled mold for which a water content necessary for breakdown cannot be obtained should preferably have its wall thinned. To this end, a thick-walled core may be provided with a cavity therein. In the present invention, the slip containing water is cast into the mold prepared by binding the powders with the water-soluble binder. The resulting phenomenon in which the mold absorbs the water content of the slip to harden the slip and to simultaneously become easy to breakdown, and the reason why a cast article of complicated shape can be formed are as stated below. As shown in FIGS. 1(a), 1(b) and 1(c), bone powder of a mold 1 is covered with a water-soluble binder 2 in an undried condition (refer to FIG. 1(a)); in a dried and cured mold, a water content has vaporized to form micro pores 3 in the interior of the mold (refer to FIG. 1(b)); and when a slip is cast into such mold, a water content (also including other liquids) in the slip permeates the pores 3 to reduce the bindability of the water-soluble binder 2 and to render the respective powders 1 independent (refer to FIG. 1(c)). As a result, a mold of low strength which is easily removed is produced, while the slip releases the water content to produce a green body. Even in a case where the mold is complicated on account of a complicated article or where a core is used, the water content necessary for breakdown is absorbed from the slip equally at various parts including a deep part, so that the various parts can break down uniformly. As the mold absorbs the water content of the slip, it turns into the mold capable of breakdown from the boundary surface at which the mold and the slip lie in contact. Meanwhile, as the slip releases the water content, it increases the amounts of contraction and deformation thereof until the green body is produced. Herein, in the present invention, the mold surface (bordering the slip) softens with the absorption of the water content, and hence, contraction and deformation arising in the process of producing the green body are not hampered. This makes it possible to obtain the green body in which the occurrence of cracks is not observed. Moreover, since the mold has had its strength lowered by the absorption of water, the removal thereof is very easy, and especially the green body having a complicated shape or a shape requiring a core may to be formed. The preparation of the mold is performed by tamping the admixture which consists of the bone powder of a mold, the water-soluble binder and water. The preparation time can be shortened by affording fluidity to the mold material. The fluidity may be afforded in such a way that an alcohol solution of the water-soluble binder which is stable in the form of a hydrate at the room temperature is prepared, and that water in an amount necessary for fixation or in a smaller amount is added thereto as water of crystallization. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1(a), 1(b) and 1(c) are diagrams for explaining the water absorptivity of a mold according to the present invention. FIG. 2 is a view for explaining an embodiment of a forming method according to the present invention. FIGS. 3(a) and 3(b) are views for explaining another embodiment of the forming method according to the present invention. DETAILED DESCRIPTION OF THE INVENTION Now, examples of the present invention will be explained. [EXAMPLE 1] 100 weight-parts of zircon, 20 weight-parts of K 2 PO 4 and 8 weight-parts of water were kneaded to prepare a mold material, which was patterned by the use of a wooden pattern and was thereafter dried at 200° C. to make a core. The core was assembled as shown in FIG. 2. That is, the core 4 was assembled together with another mold of gypsum (split in two) 5 and a lid 6. A slip (prepared by kneading 100 weight-parts of Al 2 O 3 and 16 weight-parts of water) 8 was cast into a cavity portion 7, and was let stand for one hour. After the hardening of the slip, the mold 5 and the lid 6 were taken off. Since the core 4 had absorbed a water content in the slip, it could be readily removed owing to a reduced bindability. The occurrence of cracks was not observed in a green body. [EXAMPLE 2 ] 100 weight-parts of Al 2 O 3 (250-325 meshes), 10 weight-parts of K 2 CO 3 and 12 weight-parts of water were kneaded to prepare a mold material, which was patterned by the use of a wooden pattern and was thereafter dried at 200° C. to make a core, which was assembled similarly to that in Example 1. An Al 2 O 3 slip (the same as in Example 1) was cast into the assembly, and was let stand for one hour. The core 4 could be readily removed, and the occurrence of cracks was not observed. [EXAMPLE 3] 30 weight-parts of MgO (0.1-0.3 mm in diameter), 70 weight-parts of Al 2 O 3 (250-320 meshes), 32 weight-parts of Na 2 CO 3 and 10 weight-parts of water were kneaded to prepare a mold material, which was patterned by the use of a wooden pattern and was thereafter dried at 200° C. to form a core, which was assembled as in Example 1. An Al 2 O 3 slip (the same as in Example 1) was cast into the mold assembly, and was let stand for one hour. The core 4 could be readily removed, and the occurrence of cracks was not noted. [EXAMPLE 4] Referring to FIGS. 3(a) and 3(b), a model of the same shape as that of an article 9 shown in FIG. 3(b) was made, and the model and a flask were used to make molds 10 and 11 split in two, which were assembled as shown in FIG. 3(a). The mold 10 was a mold which was fabricated from a slurry prepared by kneading 90 weight-parts of Al 2 O 3 , 8 weight-parts of Na 2 CO 3 , 28 weight-parts of ethyl alcohol and 5 weight-parts of water, while the mold 11 was a gypsum mold. An Al 2 O 3 slip (the same as in Example 1) was cast into a cavity portion 12, and was let stand for one hour. After the hardening of the slip, the mold 11 was taken off and the mold 10 was removed. Since the mold 10 had absorbed the water content of the slip, the removal was easy. No crack was noted in the surface of a green body. [EXAMPLE 5] 100 weight-parts of Al 2 O 3 (250-325 meshes), 7 weight-parts of MgSO 4 and 15 weight-parts of water were kneaded to prepare a mold material, which was patterned by the use of a wooden pattern and was thereafter dried at 200° C. to form a core, which was assembled as shown in FIG. 2. That is, the core 4 was assembled together with another mold of gypsum (split in two) 5 and a lid 6. A slip (prepared by kneading 100 weight-parts of Al 2 O 3 and 16 weight-parts of water) 8 was cast into a cavity portion 7, and was let stand for one hour. After the hardening of the slip, the mold 5 and the lid 6 were taken off. Since the core 4 had absorbed the water content of the slip, it could be readily removed owing to a reduced bindability. The occurrence of cracks was not noted in a green body. [EXAMPLE 6] 100 weight-parts of alumina (mesh No. 120), 6 weight-parts of sodium hydrogen sulfate (NaHSO 4 ) and 14 weight-parts of water were kneaded to prepare a mold material, which was patterned by the use of a wooden pattern and was thereafter dried at 200° C. to form a core. The core was assembled as shown in FIG. 2. That is, the core 4 was assembled together with another mold of gypsum (split in two) 5 and a lid 6. A slip (prepared by kneading 100 weight-parts of Al 2 O 3 and 16 weight-parts of water) 8 was cast into a cavity portion 7, and was let stand for one hour. After the hardening of the slip, the mold 5 and the lid 6 were taken off. Since the core 4 had absorbed the water content of the slip, it could be readily removed owing to a reduced bindability. The occurrence of cracks was not noted in a green body. As described above, according to the present invention, a mold is made by the use of a water-soluble binder, whereby the mold absorbs water necessary for breakdown from a slip and softens to become easy of the breakdown, while the contraction and deformation of a green body produced by the release of the water content are absorbed by the mold having softened, so that the occurrence of cracks can be prevented in the process of producing the green body and that the casting of an article having a complicated shape or a shape requiring a core becomes possible.

In a forming method and a mold wherein a slip is cast into the mold and wherein the mold is removed after hardening of the slip, the mold is patterned by the use of a water-soluble binder. The mold absorbs a water content in the slip to soften and to become easy of removal, while the slip has the water content absorbed to harden promptly. Therefore, the forming method and the mold are especially suited to produce a cast article of complicated shape.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. provisional patent application serial No. 60/289,202, filed May 7, 2001; and No. 60/312,420, filed Aug. 15, 2001; the disclosures of which are incorporated herein by reference in their entireties. REFERENCE TO SEQUENCE LISTING SUBMITTED ON COMPACT DISC [0002] The present application includes a Sequence Listing filed on one CD-R disc, provided in duplicate, containing a single file named PB0120.ST25.txt, having 32 kilobytes, last modified on May 6, 2002, and recorded on May 6, 2002. The Sequence Listing contained in said file on said disc is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention relates to a method of using artificial genes as controls in gene expression analysis systems. More particularly, the present invention relates to a method of producing Controls for use in gene expression analysis systems such as macroarrays, real-time PCR, northern blots, SAGE and microarrays, such as those provided in the Microarray ScoreCard system. [0005] 2. Description of Related Art [0006] Gene expression profiling is an important biological approach used to better understand the molecular mechanisms that govern cellular function and growth. Microarray analysis is one of the tools that can be applied to measure the relative expression levels of individual genes under different conditions. Microarray measurements often appear to be systematically biased, however, and the factors that contribute to this bias are many and ill-defined (Bowtell, D. L., Nature Genetics 21, 25-32 (1999); Brown, P. P. and Botstein, D., Nature Genetics 21, 33-37 (1999)). Others have recommended the use of “spikes” of purified mRNA at known concentrations as controls in microarray experiments. Affymetrix includes several for use with their GeneChip products. In the current state of the art, these selected genes are actual genes selected from very distantly related organisms. For example, the human chip (designed for use with human mRNA) includes control genes from bacterial and plant sources. Affymetrix sells mRNA corresponding to these genes for spiking into the labeling reaction and inclusion in the hybridization reaction. [0007] Each of the prior art controls includes transcribed sequences of DNA from some source. As a result, that source cannot be the subject of a hybridization experiment using those controls due to the inherent hybridization of the controls to its source. What is needed, therefore, is a set of controls which do not hybridize with the DNA of any source which may be the subject of an experiment. More desirably, there is a need for a control for gene expression analysis which does not hybridize with any known source. SUMMARY OF THE INVENTION [0008] Accordingly, this invention provides a process of producing controls that are useful in gene expression analysis systems designed for any species and which can be tested to insure lack of hybridization with mRNA from sources other than the control DNA itself. [0009] The invention relates in a first embodiment to a process for producing at least one control for use in a gene expression analysis system. The process comprises selecting at least one non-transcribed (inter- or intragenic) region of genomic DNA from a known sequence, designing primer pairs for said at least one non-transcribed region and amplifying said at least one non-transcribed region of genomic DNA to generate corresponding double stranded DNA, then cloning said double stranded DNA using a vector to obtain additional double stranded DNA and formulating at least one control comprising said double stranded DNA. [0010] The present invention relates in a second embodiment to a process of producing at least one control for use in a gene expression analysis system wherein testing of said at least one non-transcribed region to ensure lack of hybridization with mRNA from sources other than said at least one non-transcribed region of genomic DNA is performed. [0011] The present invention in a third embodiment relates to said process further comprising purifying said DNA and mRNA, determining the concentrations thereof and formulating at least one control comprising said DNA or of said mRNA at selected concentrations and ratios. [0012] Another embodiment of the present invention is a control for use in a gene expression analysis system comprising a known amount of at least one DNA generated from at least one non-transcribed region of genomic DNA from a known sequence, or comprising a known amount of at least one mRNA generated from DNA generated from at least one non-transcribed region of genomic DNA from a known sequence. The present invention may optionally include generating mRNA complementary to said DNA and formulating at least one control comprising said mRNA, by optionally purifying said DNA and mRNA, determining the concentrations thereof and formulating at least one control comprising said DNA or of said mRNA at selected concentrations and ratios. [0013] Another embodiment of the present invention is a control for use in a gene expression analysis system wherein a known amount of at least one DNA sequence generated from at least one non-transcribed region of genomic DNA from a known sequence, a known amount of at least one mRNA generated from DNA generated from at least one non-transcribed region of genomic DNA from a known sequence is included, and the aforementioned control wherein, said DNA and mRNA do not hybridize with any DNA or mRNA from a source other than the at least one non-transcribed region of genomic DNA. [0014] The present invention, relates to a method of using said control, as a negative control in a gene expression analysis system by adding a known amount of said control containing a known amount of DNA, to a gene expression analysis system as a control sample and subjecting the sample to hybridization conditions in the absence of complementary labeled mRNA and examining the control sample for the absence or presence of signal. [0015] Further, said controls can be used in a gene expression analysis system by adding a known amount of a said control containing a known amount of DNA to a gene expression analysis system as a control sample and subjecting the sample to hybridization conditions, in the presence of a said control containing a known amount of labeled complementary mRNA, and measuring the signal values for the labeled mRNA and determining the expression level of the DNA based on the signal value of the labeled mRNA. [0016] Additionally, said controls may be used as calibrators in a gene expression analysis system by adding a known amount of a said control containing known amounts of several DNA sequences to a gene expression analysis system as control samples and subjecting the samples to hybridization conditions in the presence of a said control containing known amounts of corresponding complementary labeled mRNAs, each mRNA being at a different concentration and measuring the signal values for the labeled mRNAs and constructing a dose-response or calibration curve based on the relationship between signal value and concentration of each mRNA. [0017] Also, the present invention relates to a method of using said controls as calibrators for gene expression ratios in a two-color gene expression analysis system by adding a known amount of at least one of said controls containing a known amount of DNA to a two-color gene expression analysis system as control samples and subjecting the samples to hybridization conditions in the presence of a said control containing known amounts of two differently labeled corresponding complementary labeled mRNAs for each DNA sample present and measuring the ratio of the signal values for the two differently labeled mRNAs and comparing the signal ratio to the ratio of concentrations of the two or more differently labelled mRNAs. [0018] A further embodiment of the present invention is a process of producing controls that are useful in gene expression analysis systems designed for any species and which can be tested to insure lack of hybridization with mRNA from sources other than the synthetic sequences of DNA from which the control is produced. [0019] One or more such controls can be produces by a process comprising synthesizing a near-random sequence of non-transcribed DNA, designing primer pairs for said at least one near random sequence and amplifying said non-transcribed DNA to generate corresponding double stranded DNA, then cloning said double stranded DNA using a vector to obtain additional double stranded DNA and formulating at least one control comprising said double stranded DNA. [0020] The process can also be used to produce at least one control for use in a gene expression analysis system wherein testing of said sequence of non-transcribed synthetic DNA to ensure lack of hybridization with mRNA from sources other than said sequence of non-transcribed DNA is performed. [0021] Additionally, mRNA complementary to said synthetic DNA can be generated and formulated to generate at least one control comprising said mRNA. [0022] DNA and mRNA can be subsequently purified, the concentrations thereof determined, and one or more controls comprising said DNA or said mRNA at selected concentrations and ratios be formulated. [0023] Another embodiment of the present invention is a control for use in a gene expression analysis system produced by the process comprises synthesizing a near-random sequence of DNA, designing primer pairs for said synthetic DNA and amplifying said DNA to generate corresponding double stranded DNA, then cloning said double stranded DNA using a vector to obtain additional double stranded DNA and formulating at least one control comprising a known amount of at least one said double stranded DNA or a known amount of at least one mRNA generated from said DNA, and optionally, wherein, said DNA and mRNA do not hybridize with any DNA or mRNA from a source other than said DNA sequence of non-transcribed DNA. [0024] The present invention, additionally, relates to a method of using said controls containing a known amount of DNA, as a negative control in a gene expression analysis system including adding a known amount of said control containing a known amount of DNA to a gene expression analysis system as a control sample, and subjecting the sample to hybridization conditions in the absence of complementary labeled mRNA and examining the control sample for the absence or presence of signal. [0025] Further, said controls may be used in a gene expression analysis system wherein a known amount of a said control containing a known amount of DNA is added to a gene expression analysis system as a control sample and subjecting the sample to hybridization conditions in the presence of a said control containing a known amount of labeled complementary mRNA and measuring the signal values for the labeled mRNA and determining the expression level of the DNA based on the signal value of the labeled mRNA. [0026] The present invention, also relates to a method of using said controls as calibrators in a gene expression analysis system including adding known amounts of a said control containing known amounts of several DNAs to a gene expression analysis system as control samples and subjecting the samples to hybridization conditions in the presence of a said control containing known amounts of corresponding complementary labeled mRNAs, each mRNA being at a different concentration and measuring the signal values for the labeled mRNAs and constructing a dose-response or calibration curve based on the relationship between signal value and concentration of each mRNA. [0027] The present invention, additionally, relates to a method of using said controls as calibrators for gene expression ratios in a two-color gene expression analysis system comprising adding a known amount of at least one of said controls containing a known amount of DNA to a two-color gene expression analysis system as control samples and subjecting the samples to hybridization conditions in the presence of a said control containing known amounts of two differently labeled corresponding complementary labeled mRNAs for each DNA sample present and measuring the ratio of the signal values for the two differently labeled mRNAs and comparing the signal ratio to the ratio of concentrations of the two or more differently labeled mRNAs. [0028] Further embodiments and uses of the current invention will become apparent from a consideration of the ensuing description. BRIEF DESCRIPTION OF THE DRAWINGS [0029] The above and other objects and advantages of the present invention will be apparent upon consideration of the following detailed description taken in conjunction with the accompanying drawings, in which like characters refer to like parts throughout, and in which: [0030] [0030]FIG. 1 presents the control nucleotide sequences of YIR1; [0031] [0031]FIG. 2 presents the control nucleotide sequences of YIR2; [0032] [0032]FIG. 3 presents the control nucleotide sequences of YIR3; [0033] [0033]FIG. 4 presents the control nucleotide sequences of YIR4; [0034] [0034]FIG. 5 presents the control nucleotide sequences of YIR5; [0035] [0035]FIG. 6 presents the control nucleotide sequences of YIR6; [0036] [0036]FIG. 7 presents the control nucleotide sequences of YIR7; [0037] [0037]FIG. 8 presents the control nucleotide sequences of YIR8; [0038] [0038]FIG. 9 presents the control nucleotide sequences of YIR11; [0039] [0039]FIG. 10 presents the control nucleotide sequences of YIR19; [0040] [0040]FIG. 11 presents the nucleotide sequences of YIR1s used in a spike mix; [0041] [0041]FIG. 12 presents the nucleotide sequences of YIR2s used in a spike mix; [0042] [0042]FIG. 13 presents the nucleotide sequences of YIR3s used in a spike mix; [0043] [0043]FIG. 14 presents the nucleotide sequences of YIR4s used in a spike mix; [0044] [0044]FIG. 15 presents the nucleotide sequences of YIR5s used in a spike mix; [0045] [0045]FIG. 16 presents the nucleotide sequences of YIR6s used in a spike mix; [0046] [0046]FIG. 17 presents the nucleotide sequences of YIR7s used in a spike mix; [0047] [0047]FIG. 18 presents the nucleotide sequences of YIR8s used in a spike mix; [0048] [0048]FIG. 19 presents the nucleotide sequences of YIR11s used in a spike mix; and [0049] [0049]FIG. 20 presents the nucleotide sequences of YIR19s used in a spike mix. DETAILED DESCRIPTION OF THE INVENTION [0050] The present invention teaches Controls for use in gene expression analysis systems such as microarrays. Many have expressed interest in being able to obtain suitable genes and spikes as controls for inclusion in their arrays. [0051] An advantage of the Controls of this invention is that a single set can be used with assay systems designed for any species, as these Controls will not be present unless intentionally added. This contrasts with the concept of using genes from “distantly related species.” For example, an analysis system directed at detecting human gene expression might employ a Bacillus subtilis gene as control, which may not be present in a human genetic material. But this control might be present in bacterial genetic material (or at least, cross hybridize), thus it may not be a good control for an experiment on bacterial gene expression. The novel Controls presented here provide an advantage over the state of the art in that the same set of controls can be used without regard to the species for the test sample RNA. [0052] The present invention employs the novel approaches of using either non-transcribed genomic sequences or totally random synthetic sequences as a template and generating both DNA and complementary “mRNA” from such sequences, for use as controls. The Controls could be devised de novo by designing near-random sequences and synthesizing them resulting in synthetic macromolecules as universal controls. Totally synthetic random DNA fragments are so designed that they do not cross-hybridize with each other or with RNA from any biologically relevant species (meaning species whose DNA or RNA might be present in the gene expression analysis system). The cost of generating such large synthetic DNA molecules can be high. However, they only need to be generated a single time. Additionally, fragment size can be increased by ligating smaller synthetic fragments together by known methods. In this way, fragments large enough to be easily cloned can be created. Through cloning and PCR sufficient quantities of DNA for use as controls can be produced and mRNA can be generated by in vitro transcription for use in controls. [0053] A simpler approach is to identify sequences from the non-transcribed regions of genomic DNA from an organism, and use these as a template for synthesis via PCR (polymerase chain reaction). Ideally, sequences of around 1000 bases (could range from 500 to 2000 bases) are selected based on computer searches of publicly accessible sequence data. The criteria for selection include: [0054] 1. The sequence must be from a non-transcribed region (intergenic or intronic region); and [0055] 2.The sequence must not have homology with or be predicted to hybridise with any known/published gene or expressed sequence tag (EST). [0056] PCR primer pairs are designed for the selected sequence(s) and PCR is performed using genomic DNA (as a template) to generate PCR fragments (dsDNA) corresponding to the non-transcribed sequence(s) as the control DNA. Additional control DNA can be cloned using a vector and standard techniques. Subsequently, standard techniques such as in vitro transcription are used to generate mRNA (complementary to the cDNA and containing a poly-A tail) as the control mRNA. Standard techniques are used for purifying the Control DNA and Control mRNA products, and for estimating their concentrations. [0057] Empirical testing is also performed to ensure lack of hybridization between the Control DNA on the array and other mRNAs, as well as with mRNA from important gene expression systems (e.g., human, mouse, Arabidopsis, etc.). [0058] The above approaches were used to generate ten control sequences from intergenic regions of the yeast Saccharomyces cerevisiae genome. Specifically, using yeast genome sequence data publicly available (http://genome-www.stanford.edu/Saccharomyces/), intergenic regions approximately 1 kb in size were identified. These sequences were BLAST'd and those showing no homology to other sequences were identified as candidates for artificial gene controls. Candidates were analyzed for GC-content and a subset with a GC-content of ≧36% were identified. Specific primer sequences have been identified and synthesized. PCR products amplified with the specific primers have been cloned directly into the pGEM™-T Easy vector (Promega Corp., Madison, Wis.). Both array targets and templates for spike mRNA have been amplified from these clones using distinct and specific primers. [0059] To maximize the chances of identifying 10 control sequences, a greater number of intergenic regions have been cloned for testing. All candidate sequences were spotted on glass microarray slides and hybridized with each candidate spike mRNA independently to identify those that cross-hybridize. Ten candidates exhibiting specific hybridization were chosen to form the specific set of controls. When used as controls, all of the ten yeast intergenic regions (YIRs) were generated by PCR with specific primers (Table 1), using 5 ng of cloned template (plasmid DNA) and a primer concentration of 0.5 μM in a 100 μl reaction volume, and cycled as follows: 35 cycles of TABLE 1 Primers used for amplification of controls. Target Forward Primer Reverse Primer YIR1 TTCGTTGGATTGAGTAAGAA SEQ ID NO: 21 GCACTTCTAGTAAGCACATG SEQ ID NO: 31 YIR2 GCGAATAACCAAAACGAGAC SEQ ID NO: 22 GCACTAAACTAAAACCGTGA SEQ ID NO: 32 YIR3 TGTTTTTGCTATATTACGTGGG SEQ ID NO: 23 CCAGCGAACACAATTCAAAA SEQ ID NO: 33 YIR4 TTTCGGTAGTGAGATGGCAG SEQ ID NO: 24 TGTACCACTTTTGCACCATA SEQ ID NO: 34 YIR5 TTAGTTTGGAACAGCAGTGT SEQ ID NO: 25 GTTTCCTCGCTCATACCCTA SEQ ID NO: 35 YIR6 AATGAGTTACCGTCTGTTAC SEQ ID NO: 26 AGTAAAGTCATGGTGGATTG SEQ ID NO: 36 YIR7 TCCTAGAGTAGCGATTCCCC SEQ ID NO: 27 GCACCTATCGTCATTGTCTT SEQ ID NO: 37 YIR8 TAGTTGGAGGTTGGTGAGTA SEQ ID NO: 28 CTTCAACTCGTACGTGATGG SEQ ID NO: 38 YIR11 CCATTCATATCATTTAGTGC SEQ ID NO: 29 CCATTCCAGTTCATATTGAA SEQ ID NO: 39 YIR19 GATTTAATACAGTACCTTTCTTCGC SEQ ID NO: 30 CCACTTTGATGGACTATTATGTATG SEQ ID NO: 40 [0060] 94° C. 20 sec., 52° C. 20 sec., 72° C. 2 min., followed by extension at 72° C. for 5 min. [0061] All YIR control mRNAs for the spike mix are generated by in vitro transcription. Templates for in vitro transcription (IVT) are generated by amplification with specific primers that are designed to introduce a T7 RNA polymerase promoter on the 5′ end and a polyT (T21) tail on the 3′ end of the PCR products (see Table 2). Run-off mRNA is produced using 1 μl of these PCR products per reaction with the AmpliScribe system (Epicentre, Madison, Wis.). IVT products are purified using the RNAEasy system (Qiagen Inc., Valencia, Calif.) and quantified by spectrophotometry. [0062] [0062]FIG. 1 through FIG. 10 presents the nucleotide sequences of the ten YIR controls, while FIGS. 11 through 20 presents the nucleotide sequences of the ten YIRs (‘s’ for spike mix) as used in a spike mix. The primer sequences used for amplifying the controls were listed in Table 1, the primer sequences used for amplifying spike mix templates were listed in Table 2. These sequences are further presented in the Sequence Listing, incorporated herein by reference in its entirety, as follows: [0063] SEQ ID NO: 1-8 [0064] nt, control nucleotide sequences YIR1 through YIR 8; [0065] SEQ ID NO: 9 [0066] nt, control nucleotide sequence YIR11; [0067] SEQ ID NO: 10 [0068] nt, control nucleotide sequence YIR19; TABLE 2 Primers used for amplification of in vitro transcription targets. Template Forward Primer Reverse Primer YIR1 GCATTAGCGGCCGCGAAATTAATA SEQ ID NO: 41 TTTTTTTTTTTTTTTTTTTTTGAA SEQ ID NO: 51 CGACTCACTATAGGGAGAAATGTC TACTTCCACTTTGGTGC GATACTGTGTTACG YIR2 GCATTAGCGGCCGCGAAATTAATA SEQ ID NO: 42 TTTTTTTTTTTTTTTTTTTTTAAT SEQ ID NO: 52 CGACTCACTATAGGGAGATTTCTT ATGCGGCTGCGCTAAAA TTTCCCTATTTCTCACTGG YIR3 GCATTAGCGGCCGCGPAATTAATA SEQ ID NO: 43 TTTTTTTTTTTTTTTTTTTTTAGT SEQ ID NO: 53 CGACTCACTATAGGGAGAACTGTA CGGTAATTTCTTTCTGG TATAAAAGAGGACTGC YIR4 GCATTAGCGGCCGCGAAATTAATA SEQ ID NO: 44 TTTTTTTTTTTTTTTTTTTTTCCA SEQ ID NO: 54 CGACTCACTATAGGGAGAATAATA CCATGACGTCATTAACTTAAAT ACTTCTGGCTTTTCGC YIR5 GCATTAGCGGCCGCGAAATTAATA SEQ ID NO: 45 TTTTTTTTTTTTTTTTTTTTTTTT SEQ ID NO: 55 CGACTCACTATAGGGAGAAGATAC AAAGGTATCATCCCTGT CGTCCTTGGATAGA YIR6 GCATTAGCGGCCGCGAAATTAATA SEQ ID NO: 46 TTTTTTTTTTTTTTTTTTTTTGCC SEQ ID NO: 56 CGACTCACTATAGGGAGATTGGGA GGACCTTTCAAGCATAA CGGTTTTTGCACTAAGAA YIR7 GCATTAGCGGCCGCGAAATTAATA SEQ ID NO: 47 TTTTTTTTTTTTTTTTTTTTTCAT SEQ ID NO: 57 CGACTCACTATAGGGAGATTCGCG AATTAGGGGTTCTGATA TATTCTTACATCTT YIR8 GCATTAGCGGCCGCGAAATTAATA SEQ ID NO: 48 TTTTTTTTTTTTTTTTTTTTTCAT SEQ ID NO: 58 CGACTCACTATAGGGAGACCAGAT GTTAGACTGAAAGCAAA TGCTTACAAAAGAA YIR11 GCATTAGCGGCCGCGAAATTAATA SEQ ID NO: 49 TTTTTTTTTTTTTTTTTTTTTATT SEQ ID NO: 59 CGACTCACTATAGGGAGATTATGG AAATCTCGGCTAGCCAC CTACTTTTCATTCC YIR19 GCATTAGCGGCCGCGAAATTAATA SEQ ID NO: 50 TTTTTTTTTTTTTTTTTTTTTAGC SEQ ID NO: 60 CGACTCACTATAGGGAGAGCTAGG ATAAAACCTCAGCTTTA ATCTATATGCGAAT [0069] The following examples demostrate how these Control DNA and Control mRNA are then used as controls in microarray gene expression experiments: [0070] 1. Control DNA included in the array, but for which no complementary artificial mRNA is spiked into the RNA sample, serves as a negative control; [0071] 2. Several different Control DNA samples may be included in an array, and the complementary Control mRNA for each is included at a known concentration, each having a different concentration of mRNA. The signals from the array features corresponding to these Controls or Calibrators may be used to construct a “dose-response curve” or calibration curve to estimate the relationship between signal and amount of mRNA from the sample; [0072] 3. In two-color microarray gene expression studies, it is possible to include different, known, levels of Control mRNA complementary to Control DNA in the labeling reaction for each channel. Comparing the ratio of signals for the two dyes from that gene can be compared to the ratio of concentrations of the two Control mRNA molecules. This can serve as a test of the accuracy of the system for determining gene expression ratios. [0073] 4. Mixtures of several different Control mRNA species can be prepared (spike mixes) at known concentrations and ratios to simplify the experimental protocol while providing a comprehensive set of precision and accuracy information. Table 3 demonstrates one embodiment of this concept. The presence of the dynamic range controls (those included in the labeling reaction at a ratio of 1:1) allows the user to determine the sensitivity of the system. They are also useful for demonstrating the precision of the normalisation method used. For the ratio controls, individual mRNAs are spiked into the two labeling reactions at different concentrations, such that a specific sequence is represented at different levels in each color. [0074] The above examples illustrate specific aspects of the present invention and are not intended to limit the scope thereof in any respect and should not be so construed. [0075] Those skilled in the art having the benefit of the teachings of the present invention as set forth above, can effect numerous modifications thereto. These modifications are to be construed as being encompassed within the scope of the present invention as set forth in the appended claims. Table 3. Suggested Control mRNA spike mix composition for two-color gene expression ratio experiments. Target Conc. In mix Cy3:Cy5 (pg/5μl mix) Relative Control Ratio Cy3 Cy5 abundance* YIR1s 1:1 33 000 33 000   3.3% YIR2s 1:1 10 000 10 000    1% YIR3s 1:1  1 000  1 000   0.1% YTR4s 1:1   330   330  0.033% YIR5s 1:1   100   100  0.01% YIR6s 1:1    33    33 0.0033% YIR7s 1:3  1 000  3 000 NA YTR8s 3:1  3 000  1 000 NA YTR11s  1:10  1 000 10 000 NA YIR19s 10:1  10 000  1 000 NA [0076] [0076] 1 60 1 1000 DNA Saccharomyces cerevisiae 1 ttcgttggat tgagtaagaa aatgtcgata ctgtgttacg tttgcaagga aaagatttag 60 ttgcgattag ccattcattc ttgtggaaac ttctttaaaa agggatggcg atggagtact 120 tatgtccaat tatgaagtca aatttatttt caaaccgtta cacgtagatt attttcctgc 180 agtggtaagt atctttgaag tgttgaaagt tttttggcac atattttttt gcggatgtgg 240 gcctgagttt cctgttagaa acaaagatat gcttaaaact aaataacatt ggaaattagg 300 gcatagtctt caatgttata cttaaacatc acagcaggag attgagatga ttgaaagaat 360 ggtgcaagaa atgattcatt aacattcttc caagttttgc aatatttgca agtattacta 420 tcagacttta gttgaagtga ctatgctatt accaaatttc actggagcca gaaaaataaa 480 gatcacttag agacaaagaa aagtaacatc ttcaacataa gccggagctc aaaagtagga 540 aatcggataa gaaacttgat tctgttattt caagtgattt tttgctgtat cgcccacgtt 600 cttgttgtag atgttttgta gatgtgggac cgaaagtaag tgaacagtga agtaaacaga 660 ataggattct aaaaaagagc ttataaactg ttctttaaaa ttttttcttt cgtgaatgtc 720 ctcgagctat ctcaaagaaa acgaaatctt cattcaactt aagtgtaggt attatttgct 780 gtttcatcaa atgcggcacc aaagtggaag tattctagtc agttagtttt tcattgtgag 840 gaattgatat gtcgttctct gatagaacca cgctaagttg gtgttcaatt ttttgcaatt 900 cggtagtaat tatgccttgc aacatgtttt attcttttat agtgtgatac cgtcaatatg 960 atgatttgcg gtggagcatg catgtgctta ctagaagtgc 1000 2 1000 DNA Saccharomyces cerevisiae 2 gcgaataacc aaaacgagac tactttttac cattacaacc attttctttt tccctatttc 60 tcactggttg acagaaatca gtgtgctatc atcctaccat atgcgctaaa cttattgtct 120 ttctcctcct agagatgctg tattccatgc atattctgaa cgatgggttg gtgtttttat 180 caagcaaggt taatcacatg gcgtggcttg ctccacacat cagtagaaaa cgcataccgc 240 agcggaatcc ttaaataata agtgatttta ctgttcatca actacaatcg gactctttca 300 caattaccct tcttgttttc cacatttact gttaaatgaa gggatgtaca gaaggcttag 360 gaaaacctgt gctgaatact ggatggacac tgcattccca cagtgaaact tttatagata 420 cactgtcagt tattttcgaa ctttcatcaa gttgctgagt tttagtatcc ctttgcctta 480 gctatatgtt tgaatgagca aaatatttgc aatgtctcta gctttcttga aatattggtt 540 tatattgagg gcttggtaag atttcaaatt tcactttgaa atactcagga gaaaaatcat 600 gctcttttga taatttggtg actaaacata cataaaacag tttaattttg ggtggtaatg 660 gctgtgtgac tagctataga aagaaaaaaa ttaaaaaaaa aaaaaaaaat caagtagttc 720 ctgcactgcg acgtccatta tagcattatg aattggtccc tgatttacgc atgcgataaa 780 ctatttttag cgcagccgca tattatccga gaataacttc cgacataaga aaattcgcag 840 aaaatagata aaaaactgct cttggcattc ttcacttcct ctattacaca ctgtgtcata 900 ccacaatcat ctcacagtat gtatttgtat gtttatacat gctataacgt aaaacaatgt 960 agaatatata tctaaatacc tcacggtttt agtttagtgc 1000 3 969 DNA Saccharomyces cerevisiae 3 tgtttttgct atattacgtg ggttttttat ttatactgta tataaaagag gactgcaata 60 gcacaagatt aagatagaat ggcttcaaac agccgccttt tatacatatt ggtaaaagct 120 cgcgaatcgc accatatccc ttatcctgta atcaaatcga tctaggtgca gatacagatc 180 aattcataaa aagaaattga agcaccagtt tatcactact acactatctt tttctttttt 240 tttttttttt gcgaagtttc gccctttgtt caatatcact tgataagttg tgggcttttt 300 ctgtcactca ttcggcttaa aaagtattcg ttcttttgtg ttttatgaaa agggaacgtg 360 atataaaaaa acatcctttg gtgtgggaca tgggcttttg tttagagaat ggttatcact 420 accgccccca cccttgaaag ccacagaaaa tgaaaaagta tgtgaataag gtgtgaactc 480 tataacattt tggccaaatg ccacagccga tctgcatatt ccaatggaca taatgcaaca 540 acaattgatg tcacattctc ttacacactt cgattggtcc gtacgtagta ctttttacat 600 aactgactca ggcgtttcct tcattgaaat gctcatctat tgccaagtac atagaatcca 660 cagtgcatag gtttatgaga tgcttggaag atgtacgatc gcctgcacta tattagtata 720 ttttttcagg ctttacaaaa ccagaaagaa attaccgact gtaatactta atttccatga 780 ttttaatcgt atggtccgtg aggaaagagg aattttaggt aaaaaaaaac ctttgtctat 840 caaaacataa aagaaaagaa aaaaattaaa ttgaataagt cagcttttta gcatgaccac 900 agtaataata gtaatacgat atcagcatga gctgctaaac attaagaatt tttgaattgt 960 gttcgctgg 969 4 1037 DNA Saccharomyces cerevisiae 4 tttcggtagt gagatggcag ttcgaggggt tttttattca aaataataac ttctggcttt 60 tcgcttttat atagcagaaa aaaaagccgt cgaggcgcgc gcgttcatgc aatggctcag 120 taacctcggg atagaaaaag ggcaacaatg ttgagctatt ttaggcacag aaactttact 180 attcgaaaag ggcatccatt tcatttccga ttttctatct agctcactcg ataatcgtaa 240 tagtactttt ataaaacttt agtgcgggta ctgtgagagt gtgccgtaac tttggtttac 300 atttaaggtg cgaccagcaa tgtcactact tttacaacaa ccgccatatg gctcgagaat 360 ttcattatca catggaatgc ctgtgacaaa actgtgtaaa tatctaatag aaattagatg 420 tagctgtcac aaatatttac acaggaaaga gcctgtccta cgagtatctt acatgaagat 480 tcatagaacc aatttacttg cgaatgtgaa caacctttca acatcatttc aataccattt 540 tccctcctta tgtttggtgt cactgtaaag cggatcaaag caaaacatag aggtacggtg 600 gtgctaagat catgcatgac ctctgggtaa ttactacttc tcccgcttgt tttgagattc 660 tgtatataaa tatttcaaac aaaaggatag agcgcggatg gcaggcctta tagtaaaagt 720 tattcgtttt aatcatgtgt cagtatgaga ttctatgaca atagtatgag aagatagggt 780 gaagtaaaag tatctgtatg actatagagt gcagttatat tacaatatat tgaatagatc 840 ataatggtat gacgatatta aggaacattt aagttaatga cgtcatggtg gtatagatac 900 gcaattgagt gtgtttatgt attattgttg aaaagtagaa tatttttatg tttaggtgat 960 tttgatgata tttttatgta atattgacat aagtgcatat aaattgagtg gttagtatat 1020 ggtgcaaaag tggtaca 1037 5 950 DNA Saccharomyces cerevisiae 5 ttagtttgga acagcagtgt agataccgtc cttggataga gcgctggaga tagctggtct 60 caatctggtg gagtaccatg ggacaccagt gatgactcta gtgacttgat cagcgggaat 120 accagtcaac atagtggtga aatcaccgta gttgaaaaca gcttcagcaa tttcaactgg 180 gtaagtttca gttggatgag cagcttggaa catatagtat tcagccaaat gagctctgat 240 atctgagacg tagacaccta attcgaccag gttaactctt tcgtcagagg gagataaagt 300 agtggtggct ggggcagcag cgacaccagc agcaatagca gcgacaccag caacaattga 360 agttagtttg accatttttt tcgattgaac ttttgtagat ctttttagtg aagatgtgag 420 ctcactcgaa tgtaaataac aatgccaaat tgtcggaaag agttaatcaa agctgctcta 480 tttatatgcc gttttttaat aagcgacgga cgaacagata aattgttgaa tagctatttc 540 actgctgata tttctcttac ttgggctccc ctatcccata ctcttcacca ctacaaatat 600 gcagttgccc tttcttcaac aatgcttttt ttatagatct cgtatacgga tccgcgcctt 660 tgtactacct atatcttatt atgatatata caggagcaca ggaatgttcg gtacagggat 720 gataccttta aaggaagttt tggcatgcct tgacaacttc aattaatctt tggccaagaa 780 aatgaaccag aaatcaaatt ttattctgtg ccctctgaac gagggcaata tccaatgttt 840 gacactaaac ggttgtcagg agaaaaattg aatgtttccc aaatcagaaa cattaaaatc 900 cctctatatg atcagaggag tcgtacctgt tagggtatga gcgaggaaac 950 6 982 DNA Saccharomyces cerevisiae 6 aatgagttac cgtctgttac ttttgggacg gtttttgcac taagaacaga cgagtttacg 60 gttatcctca acaagcaagc aagtatttgc taatctagat gccattccga atcattactc 120 atacgttact attgagagat gttttacaat agatgagaag aatacaatgt ccagagctcc 180 tggtatgcta gagtgcatat tccaggtctt attcgaatca tatcataccg tccatttcaa 240 caatggtgaa atgtggtcca catatatcag aaatcttaac atttagtgag gagagccagt 300 agaaaaatgt gcgcaagcgg aaagaagtca ttcacagaca cgtttaacaa aacaccacca 360 cagcagcttt gtctcttgat tctgatcagt ttgccatcga agaagcaaaa ttgtggtgtt 420 atttttttca aacaaaactt ttttggcaac agcagttttc ttctggatat ttgtacttta 480 tcatccaacc gatgaaagct ggtttcctgt caacctacat ttaaatggcc cgtacttctt 540 caaaaccgct agataagcaa attaacccaa cttttgagcg tcctaaattc cccttggctc 600 agaagactcg ttaatatggg aagtttaagt cctaccatat aatcaaattg gaagctttct 660 gtgttcgaat ggctattcta accgctgggc tattaatcag aggggaagtg aaatgaccga 720 gacgtattat acgtcatgtt gacatcaaca atttaaggaa aaaaataaaa aaaagcaatg 780 aaaaagggtt tttttaagtt gaagaccctt ttcaaatata tgttgctttg aattgtatct 840 accgtctcgt ttcttctgct ttaccgtttt tttttgcctt ctttagatat gtcttttatg 900 cttgaaaggt ccggctttaa tgcattcatc taaacgtagt attcctattt ttgaactgct 960 accaatccac catgacttta ct 982 7 1010 DNA Saccharomyces cerevisiae 7 tcctagagta gcgattcccc ttcgcgtatt cttacatctt cgaagagaac ttctggtgta 60 agtataataa atattatagc tctatcgaat ggtgcaatta tttaccaaat tctcaatagg 120 aatccataat actacatacg atactaatat tctagtattt ttatacttat tatttctttt 180 ttattacacc agcaatcgtt gcaaattatc ttctgataga atttctgagg gtatcctaaa 240 cttatgccat tttcttggac tgtaaatcat acttggatgt tgtgcattag tcaataatcg 300 gttcttgttc caacgattac atgtaaatga agggagaaat aattatggta aatcatgcgg 360 cggtcctttt ggtgatgcag tatccatagt cactacataa caatcttagt caccttgtat 420 tgattcacca cataatcctg cagagcccgc tatgtcctta atctgcgcga taactctcct 480 acccctgaat tttgagagcg ccatagcaaa ccgataaagc tggcacaatt aaaggtatcg 540 gtgttgtcag aattaggtgc ctcctgcttt tttttttttc ctgctcttat atccgttata 600 tccgaatgat ttttatcgct tgtttaaaaa atactttccc gatatatata tatagtctcc 660 ctttaaattt gtttccggta agtttttaac accaataaat gaaaagaaat gactacggtg 720 atgaatatga gccgcgcatt gaatcaggtt atgtaagtat cagaacccct aattatgatg 780 tcactcttac ccttcgatgg ctaagcggcg actgggatgc cgggaaaagc tctacaaatc 840 tactaaaaaa gtcaaatata cagctgtaaa cttctttcct cgtctacatc atggtaacga 900 ttgttcaatc tttacttcgt gtcttttttt ttttctatgt actttctatt ccaacctatg 960 tgaagactaa aattcacctt agtaaacgta aagacaatga cgataggtgc 1010 8 951 DNA Saccharomyces cerevisiae 8 tagttggagg ttggtgagta ccagattgct tacaaaagaa tagcgagcca acatttgctc 60 tgcctcaggc ctcttggtgc tgcttgaaga ctcatcttat atggcttttg tatgtcatga 120 tttgttcttg tacattatgt gttgatatta aacaaattga tttttttttt tttgcgatag 180 caagcagata atgaaagaga caaggacttg gaacatccga taagactgcg ccgatatcga 240 tcttacagtc cttcccttgt gtcatgactt tcggaaaagc atcctcgtcg actggtagtt 300 tgctgtctgt cacgtgctga agggtctgat acattttttt aaagataaga gacggggttt 360 acccttcgga ggactaagcg agatctccaa gtaaagatct cgcttatcaa gaaagcagcc 420 aagtgtggaa cgtccttttt tttggtttca aaaagatatt caacagttta cactgcagct 480 ttaattgcct caaaaggata tcatgaggtg atctagggtc agaagggaaa gattacagca 540 tcttgagttg aatcacatct gcaaaaggtg gtattattga cgttgctctt ccttaatgga 600 aactcatggg gtttggaaag gaggtgcggt aatctatttt tttcgaacac aaaacctaac 660 cttgaaaaga aactgtccaa tttcattgaa cttacctcag aacgggccgg agtctttgct 720 ttcagtctaa catggtctaa tttcttcgaa aagcttcatt taattgttag actgtggttt 780 tacaaggaaa aaaccagtgc tatactgaag cgatacccag aactaattac cttgtgtgac 840 gattcggctc agcgaaacgg acatggtaaa attgggaatt tgaaagcagg cagcagcctt 900 gtacagcgac atgacgatag gtttagaatc cccatcacgt acgagttgaa g 951 9 952 DNA Saccharomyces cerevisiae 9 ccattcatat catttagtgc ttatggctac ttttcattcc tcaattattg taaattgacc 60 atcttaatta tatttctgat attgagtagg tggacttcat tagtattttt acaaatatta 120 tcaccttctt atgtaggatt agcattacat accctctaat taaaaaaagt taacattaat 180 tacattttaa aaaaaattgt aatagtatga tagtaggacc tgacagccat ttgaataagg 240 tttcgagtgc tttaacgttc cactgatttt atgtagttca tatgggggtt agtctggttt 300 gaggaggaga atttcaggga agcagtggcc gttgaatctc cctgtagggc gctgattatt 360 tttatcctaa taatccaaaa atgacaatgt caataaagaa aacttaccga gttctgtgaa 420 tttctcccta aaaaattact aattatacct gggcgagttt tgaactcttt ggcaaataaa 480 cttggggtaa acctttcgat tataaagacg ttactgctca aaaatgtgta gaagcataag 540 gagatattct ctcgtatgtt taattggagt tggctttttt ggactctgaa gtttgagtat 600 gggaggggaa gtaatcgaga ttagattccc tgatgttcac atatggggat aaagaatgct 660 ttttgggata tgattgtttc tttccgtcgt tacggttgta ggtgcaacga attgcgtaag 720 ggtggctagc cgagatttaa tgacgacgca aaagggaata actgtgacag gaagatgaat 780 tcacaaagtt tataaaaaga aagggcgatg cactgctaca tggttgaaca aggcactaca 840 taattcacag cttgtagctt gtaaataaaa agagcattca cgcgatatac gattttcaat 900 gatcactcta agaggaacgg cgaaaaatag aattcaatat gaactggaat gg 952 10 967 DNA Saccharomyces cerevisiae 10 gatttaatac agtacctttc ttcgctagga tctatatgcg aatatatcac atatgtaaat 60 tataagctca tcgcaaaacc aaaaaaaaaa aaattttcaa taatttttca ctaatcttca 120 aaaacaaatg gggtaacccg tacaagagtt attaaaaccc aaaatgacaa aatcgcgaca 180 attcaatcct acttaattag caataacata ctagcggtag agctactatc acatgttgaa 240 ccttgaatgc tcaattcatt gtactcaata ctgctatcaa aagaaaaaaa atgtattaat 300 tatattcttg tcaaaatcaa ttttacacta taagaggaaa atgttcttca gtcctagtaa 360 cattagtttt ctccctttgc tagagacttt acataatatc ctagaaggta aaattcgata 420 atacagcagt aaagtcgtat attggtagca atccttggtg acgctgactt tttttttttg 480 taattttatt gtttagttca tgataaaaaa cttcaaatca cttttaatct ggtagacaga 540 gaaaacaaat cgaaacgaaa atagagaact acgaataaaa aaatataagt ggagaagatc 600 gtcactacgc attaaacaat attgatcgct caatgccagt actgcgcgta aaagtttagt 660 aacttaacga tttaggcaca atttgagaaa aatttcgccc tgcagtaagt atgttattca 720 gtacgatata aagctgaggt tttatgctgg caacgttcag attttttagg ttatcagcaa 780 tgttaaaata ttaaatagga tacttttatt gtttgagacc accctcaatg ccagatatgt 840 taaacgcttt tttctggagt gaggtatcat agaaaaaggc tcgagtacat caagcactta 900 aaggttcaac actctactgt tacttcttta agctaagcta ttcatacata atagtccatc 960 aaagtgg 967 11 795 DNA Saccharomyces cerevisiae 11 aatgtcgata ctgtgttacg tttgcaagga aaagatttag ttgcgattag ccattcattc 60 ttgtggaaac ttctttaaaa agggatggcg atggagtact tatgtccaat tatgaagtca 120 aatttatttt caaaccgtta cacgtagatt attttcctgc agtggtaagt atctttgaag 180 tgttgaaagt tttttggcac atattttttt gcggatgtgg gcctgagttt cctgttagaa 240 acaaagatat gcttaaaact aaataacatt ggaaattagg gcatagtctt caatgttata 300 cttaaacatc acagcaggag attgagatga ttgaaagaat ggtgcaagaa atgattcatt 360 aacattcttc caagttttgc aatatttgca agtattacta tcagacttta gttgaagtga 420 ctatgctatt accaaatttc actggagcca gaaaaataaa gatcacttag agacaaagaa 480 aagtaacatc ttcaacataa gccggagctc aaaagtagga aatcggataa gaaacttgat 540 tctgttattt caagtgattt tttgctgtat cgcccacgtt cttgttgtag atgttttgta 600 gatgtgggac cgaaagtaag tgaacagtga agtaaacaga ataggattct aaaaaagagc 660 ttataaactg ttctttaaaa ttttttcttt cgtgaatgtc ctcgagctat ctcaaagaaa 720 acgaaatctt cattcaactt aagtgtaggt attatttgct gtttcatcaa atgcggcacc 780 aaagtggaag tattc 795 12 762 DNA Saccharomyces cerevisiae 12 tttctttttc cctatttctc actggttgac agaaatcagt gtgctatcat cctaccatat 60 gcgctaaact tattgtcttt ctcctcctag agatgctgta ttccatgcat attctgaacg 120 atgggttggt gtttttatca agcaaggtta atcacatggc gtggcttgct ccacacatca 180 gtagaaaacg cataccgcag cggaatcctt aaataataag tgattttact gttcatcaac 240 tacaatcgga ctctttcaca attacccttc ttgttttcca catttactgt taaatgaagg 300 gatgtacaga aggcttagga aaacctgtgc tgaatactgg atggacactg cattcccaca 360 gtgaaacttt tatagataca ctgtcagtta ttttcgaact ttcatcaagt tgctgagttt 420 tagtatccct ttgccttagc tatatgtttg aatgagcaaa atatttgcaa tgtctctagc 480 tttcttgaaa tattggttta tattgagggc ttggtaagat ttcaaatttc actttgaaat 540 actcaggaga aaaatcatgc tcttttgata atttggtgac taaacataca taaaacagtt 600 taattttggg tggtaatggc tgtgtgacta gctatagaaa gaaaaaaatt aaaaaaaaaa 660 aaaaaaatca agtagttcct gcactgcgac gtccattata gcattatgaa ttggtccctg 720 atttacgcat gcgataaact atttttagcg cagccgcata tt 762 13 726 DNA Saccharomyces cerevisiae 13 actgtatata aaagaggact gcaatagcac aagattaaga tagaatggct tcaaacagcc 60 gccttttata catattggta aaagctcgcg aatcgcacca tatcccttat cctgtaatca 120 aatcgatcta ggtgcagata cagatcaatt cataaaaaga aattgaagca ccagtttatc 180 actactacac tatctttttc tttttttttt ttttttgcga agtttcgccc tttgttcaat 240 atcacttgat aagttgtggg ctttttctgt cactcattcg gcttaaaaag tattcgttct 300 tttgtgtttt atgaaaaggg aacgtgatat aaaaaaacat cctttggtgt gggacatggg 360 cttttgttta gagaatggtt atcactaccg cccccaccct tgaaagccac agaaaatgaa 420 aaagtatgtg aataaggtgt gaactctata acattttggc caaatgccac agccgatctg 480 catattccaa tggacataat gcaacaacaa ttgatgtcac attctcttac acacttcgat 540 tggtccgtac gtagtacttt ttacataact gactcaggcg tttccttcat tgaaatgctc 600 atctattgcc aagtacatag aatccacagt gcataggttt atgagatgct tggaagatgt 660 acgatcgcct gcactatatt agtatatttt ttcaggcttt acaaaaccag aaagaaatta 720 ccgact 726 14 849 DNA Saccharomyces cerevisiae 14 ataataactt ctggcttttc gcttttatat agcagaaaaa aaagccgtcg aggcgcgcgc 60 gttcatgcaa tggctcagta acctcgggat agaaaaaggg caacaatgtt gagctatttt 120 aggcacagaa actttactat tcgaaaaggg catccatttc atttccgatt ttctatctag 180 ctcactcgat aatcgtaata gtacttttat aaaactttag tgcgggtact gtgagagtgt 240 gccgtaactt tggtttacat ttaaggtgcg accagcaatg tcactacttt tacaacaacc 300 gccatatggc tcgagaattt cattatcaca tggaatgcct gtgacaaaac tgtgtaaata 360 tctaatagaa attagatgta gctgtcacaa atatttacac aggaaagagc ctgtcctacg 420 agtatcttac atgaagattc atagaaccaa tttacttgcg aatgtgaaca acctttcaac 480 atcatttcaa taccattttc cctccttatg tttggtgtca ctgtaaagcg gatcaaagca 540 aaacatagag gtacggtggt gctaagatca tgcatgacct ctgggtaatt actacttctc 600 ccgcttgttt tgagattctg tatataaata tttcaaacaa aaggatagag cgcggatggc 660 aggccttata gtaaaagtta ttcgttttaa tcatgtgtca gtatgagatt ctatgacaat 720 agtatgagaa gatagggtga agtaaaagta tctgtatgac tatagagtgc agttatatta 780 caatatattg aatagatcat aatggtatga cgatattaag gaacatttaa gttaatgacg 840 tcatggtgg 849 15 712 DNA Saccharomyces cerevisiae 15 agataccgtc cttggataga gcgctggaga tagctggtct caatctggtg gagtaccatg 60 ggacaccagt gatgactcta gtgacttgat cagcgggaat accagtcaac atagtggtga 120 aatcaccgta gttgaaaaca gcttcagcaa tttcaactgg gtaagtttca gttggatgag 180 cagcttggaa catatagtat tcagccaaat gagctctgat atctgagacg tagacaccta 240 attcgaccag gttaactctt tcgtcagagg gagataaagt agtggtggct ggggcagcag 300 cgacaccagc agcaatagca gcgacaccag caacaattga agttagtttg accatttttt 360 tcgattgaac ttttgtagat ctttttagtg aagatgtgag ctcactcgaa tgtaaataac 420 aatgccaaat tgtcggaaag agttaatcaa agctgctcta tttatatgcc gttttttaat 480 aagcgacgga cgaacagata aattgttgaa tagctatttc actgctgata tttctcttac 540 ttgggctccc ctatcccata ctcttcacca ctacaaatat gcagttgccc tttcttcaac 600 aatgcttttt ttatagatct cgtatacgga tccgcgcctt tgtactacct atatcttatt 660 atgatatata caggagcaca ggaatgttcg gtacagggat gataccttta aa 712 16 893 DNA Saccharomyces cerevisiae 16 ttgggacggt ttttgcacta agaacagacg agtttacggt tatcctcaac aagcaagcaa 60 gtatttgcta atctagatgc cattccgaat cattactcat acgttactat tgagagatgt 120 tttacaatag atgagaagaa tacaatgtcc agagctcctg gtatgctaga gtgcatattc 180 caggtcttat tcgaatcata tcataccgtc catttcaaca atggtgaaat gtggtccaca 240 tatatcagaa atcttaacat ttagtgagga gagccagtag aaaaatgtgc gcaagcggaa 300 agaagtcatt cacagacacg tttaacaaaa caccaccaca gcagctttgt ctcttgattc 360 tgatcagttt gccatcgaag aagcaaaatt gtggtgttat ttttttcaaa caaaactttt 420 ttggcaacag cagttttctt ctggatattt gtactttatc atccaaccga tgaaagctgg 480 tttcctgtca acctacattt aaatggcccg tacttcttca aaaccgctag ataagcaaat 540 taacccaact tttgagcgtc ctaaattccc cttggctcag aagactcgtt aatatgggaa 600 gtttaagtcc taccatataa tcaaattgga agctttctgt gttcgaatgg ctattctaac 660 cgctgggcta ttaatcagag gggaagtgaa atgaccgaga cgtattatac gtcatgttga 720 catcaacaat ttaaggaaaa aaataaaaaa aagcaatgaa aaagggtttt tttaagttga 780 agaccctttt caaatatatg ttgctttgaa ttgtatctac cgtctcgttt cttctgcttt 840 accgtttttt tttgccttct ttagatatgt cttttatgct tgaaaggtcc ggc 893 17 757 DNA Saccharomyces cerevisiae 17 ttcgcgtatt cttacatctt cgaagagaac ttctggtgta agtataataa atattatagc 60 tctatcgaat ggtgcaatta tttaccaaat tctcaatagg aatccataat actacatacg 120 atactaatat tctagtattt ttatacttat tatttctttt ttattacacc agcaatcgtt 180 gcaaattatc ttctgataga atttctgagg gtatcctaaa cttatgccat tttcttggac 240 tgtaaatcat acttggatgt tgtgcattag tcaataatcg gttcttgttc caacgattac 300 atgtaaatga agggagaaat aattatggta aatcatgcgg cggtcctttt ggtgatgcag 360 tatccatagt cactacataa caatcttagt caccttgtat tgattcacca cataatcctg 420 cagagcccgc tatgtcctta atctgcgcga taactctcct acccctgaat tttgagagcg 480 ccatagcaaa ccgataaagc tggcacaatt aaaggtatcg gtgttgtcag aattaggtgc 540 ctcctgcttt tttttttttc ctgctcttat atccgttata tccgaatgat ttttatcgct 600 tgtttaaaaa atactttccc gatatatata tatagtctcc ctttaaattt gtttccggta 660 agtttttaac accaataaat gaaaagaaat gactacggtg atgaatatga gccgcgcatt 720 gaatcaggtt atgtaagtat cagaacccct aattatg 757 18 714 DNA Saccharomyces cerevisiae 18 ccagattgct tacaaaagaa tagcgagcca acatttgctc tgcctcaggc ctcttggtgc 60 tgcttgaaga ctcatcttat atggcttttg tatgtcatga tttgttcttg tacattatgt 120 gttgatatta aacaaattga tttttttttt tttgcgatag caagcagata atgaaagaga 180 caaggacttg gaacatccga taagactgcg ccgatatcga tcttacagtc cttcccttgt 240 gtcatgactt tcggaaaagc atcctcgtcg actggtagtt tgctgtctgt cacgtgctga 300 agggtctgat acattttttt aaagataaga gacggggttt acccttcgga ggactaagcg 360 agatctccaa gtaaagatct cgcttatcaa gaaagcagcc aagtgtggaa cgtccttttt 420 tttggtttca aaaagatatt caacagttta cactgcagct ttaattgcct caaaaggata 480 tcatgaggtg atctagggtc agaagggaaa gattacagca tcttgagttg aatcacatct 540 gcaaaaggtg gtattattga cgttgctctt ccttaatgga aactcatggg gtttggaaag 600 gaggtgcggt aatctatttt tttcgaacac aaaacctaac cttgaaaaga aactgtccaa 660 tttcattgaa cttacctcag aacgggccgg agtctttgct ttcagtctaa catg 714 19 721 DNA Saccharomyces cerevisiae 19 ttatggctac ttttcattcc tcaattattg taaattgacc atcttaatta tatttctgat 60 attgagtagg tggacttcat tagtattttt acaaatatta tcaccttctt atgtaggatt 120 agcattacat accctctaat taaaaaaagt taacattaat tacattttaa aaaaaattgt 180 aatagtatga tagtaggacc tgacagccat ttgaataagg tttcgagtgc tttaacgttc 240 cactgatttt atgtagttca tatgggggtt agtctggttt gaggaggaga atttcaggga 300 agcagtggcc gttgaatctc cctgtagggc gctgattatt tttatcctaa taatccaaaa 360 atgacaatgt caataaagaa aacttaccga gttctgtgaa tttctcccta aaaaattact 420 aattatacct gggcgagttt tgaactcttt ggcaaataaa cttggggtaa acctttcgat 480 tataaagacg ttactgctca aaaatgtgta gaagcataag gagatattct ctcgtatgtt 540 taattggagt tggctttttt ggactctgaa gtttgagtat gggaggggaa gtaatcgaga 600 ttagattccc tgatgttcac atatggggat aaagaatgct ttttgggata tgattgtttc 660 tttccgtcgt tacggttgta ggtgcaacga attgcgtaag ggtggctagc cgagatttaa 720 t 721 20 725 DNA Saccharomyces cerevisiae 20 gctaggatct atatgcgaat atatcacata tgtaaattat aagctcatcg caaaaccaaa 60 aaaaaaaaaa ttttcaataa tttttcacta atcttcaaaa acaaatgggg taacccgtac 120 aagagttatt aaaacccaaa atgacaaaat cgcgacaatt caatcctact taattagcaa 180 taacatacta gcggtagagc tactatcaca tgttgaacct tgaatgctca attcattgta 240 ctcaatactg ctatcaaaag aaaaaaaatg tattaattat attcttgtca aaatcaattt 300 tacactataa gaggaaaatg ttcttcagtc ctagtaacat tagttttctc cctttgctag 360 agactttaca taatatccta gaaggtaaaa ttcgataata cagcagtaaa gtcgtatatt 420 ggtagcaatc cttggtgacg ctgacttttt ttttttgtaa ttttattgtt tagttcatga 480 taaaaaactt caaatcactt ttaatctggt agacagagaa aacaaatcga aacgaaaata 540 gagaactacg aataaaaaaa tataagtgga gaagatcgtc actacgcatt aaacaatatt 600 gatcgctcaa tgccagtact gcgcgtaaaa gtttagtaac ttaacgattt aggcacaatt 660 tgagaaaaat ttcgccctgc agtaagtatg ttattcagta cgatataaag ctgaggtttt 720 atgct 725 21 20 DNA Saccharomyces cerevisiae 21 ttcgttggat tgagtaagaa 20 22 20 DNA Saccharomyces cerevisiae 22 gcgaataacc aaaacgagac 20 23 22 DNA Saccharomyces cerevisiae 23 tgtttttgct atattacgtg gg 22 24 20 DNA Saccharomyces cerevisiae 24 tttcggtagt gagatggcag 20 25 20 DNA Saccharomyces cerevisiae 25 ttagtttgga acagcagtgt 20 26 20 DNA Saccharomyces cerevisiae 26 aatgagttac cgtctgttac 20 27 20 DNA Saccharomyces cerevisiae 27 tcctagagta gcgattcccc 20 28 20 DNA Saccharomyces cerevisiae 28 tagttggagg ttggtgagta 20 29 20 DNA Saccharomyces cerevisiae 29 ccattcatat catttagtgc 20 30 25 DNA Saccharomyces cerevisiae 30 gatttaatac agtacctttc ttcgc 25 31 20 DNA Saccharomyces cerevisiae 31 gcacttctag taagcacatg 20 32 20 DNA Saccharomyces cerevisiae 32 gcactaaact aaaaccgtga 20 33 20 DNA Saccharomyces cerevisiae 33 ccagcgaaca caattcaaaa 20 34 20 DNA Saccharomyces cerevisiae 34 tgtaccactt ttgcaccata 20 35 20 DNA Saccharomyces cerevisiae 35 gtttcctcgc tcatacccta 20 36 20 DNA Saccharomyces cerevisiae 36 agtaaagtca tggtggattg 20 37 20 DNA Saccharomyces cerevisiae 37 gcacctatcg tcattgtctt 20 38 20 DNA Saccharomyces cerevisiae 38 cttcaactcg tacgtgatgg 20 39 20 DNA Saccharomyces cerevisiae 39 ccattccagt tcatattgaa 20 40 25 DNA Saccharomyces cerevisiae 40 ccactttgat ggactattat gtatg 25 41 62 DNA Saccharomyces cerevisiae 41 gcattagcgg ccgcgaaatt aatacgactc actataggga gaaatgtcga tactgtgtta 60 cg 62 42 67 DNA Saccharomyces cerevisiae 42 gcattagcgg ccgcgaaatt aatacgactc actataggga gatttctttt tccctatttc 60 tcactgg 67 43 64 DNA Saccharomyces cerevisiae 43 gcattagcgg ccgcgaaatt aatacgactc actataggga gaactgtata taaaagagga 60 ctgc 64 44 64 DNA Saccharomyces cerevisiae 44 gcattagcgg ccgcgaaatt aatacgactc actataggga gaataataac ttctggcttt 60 tcgc 64 45 62 DNA Saccharomyces cerevisiae 45 gcattagcgg ccgcgaaatt aatacgactc actataggga gaagataccg tccttggata 60 ga 62 46 66 DNA Saccharomyces cerevisiae 46 gcattagcgg ccgcgaaatt aatacgactc actataggga gattgggacg gtttttgcac 60 taagaa 66 47 62 DNA Saccharomyces cerevisiae 47 gcattagcgg ccgcgaaatt aatacgactc actataggga gattcgcgta ttcttacatc 60 tt 62 48 62 DNA Saccharomyces cerevisiae 48 gcattagcgg ccgcgaaatt aatacgactc actataggga gaccagattg cttacaaaag 60 aa 62 49 62 DNA Saccharomyces cerevisiae 49 gcattagcgg ccgcgaaatt aatacgactc actataggga gattatggct acttttcatt 60 cc 62 50 62 DNA Saccharomyces cerevisiae 50 gcattagcgg ccgcgaaatt aatacgactc actataggga gagctaggat ctatatgcga 60 at 62 51 41 DNA Saccharomyces cerevisiae 51 tttttttttt tttttttttt tgaatacttc cactttggtg c 41 52 41 DNA Saccharomyces cerevisiae 52 tttttttttt tttttttttt taatatgcgg ctgcgctaaa a 41 53 41 DNA Saccharomyces cerevisiae 53 tttttttttt tttttttttt tagtcggtaa tttctttctg g 41 54 46 DNA Saccharomyces cerevisiae 54 tttttttttt tttttttttt tccaccatga cgtcattaac ttaaat 46 55 41 DNA Saccharomyces cerevisiae 55 tttttttttt tttttttttt ttttaaaggt atcatccctg t 41 56 41 DNA Saccharomyces cerevisiae 56 tttttttttt tttttttttt tgccggacct ttcaagcata a 41 57 41 DNA Saccharomyces cerevisiae 57 tttttttttt tttttttttt tcataattag gggttctgat a 41 58 41 DNA Saccharomyces cerevisiae 58 tttttttttt tttttttttt tcatgttaga ctgaaagcaa a 41 59 41 DNA Saccharomyces cerevisiae 59 tttttttttt tttttttttt tattaaatct cggctagcca c 41 60 41 DNA Saccharomyces cerevisiae 60 tttttttttt tttttttttt tagcataaaa cctcagcttt a 41

Method of producing controls for use in gene expression analysis systems such as macroarrays, real-time PCR, northern blots, SAGE and microarrays. The controls are generated either from near-random sequence of DNA, or from inter- or intragenic regions of a genome. Ten specific control sequences are also disclosed. Also presented are methods of using these controls, including as negative controls, positive controls, and as calibrators of a gene expression analysis system.

BACKGROUND OF THE INVENTION The present invention relates to an improvement in the slow fuel controller of a carburetor. Recently, there are increasing demands for carburetors of automobile engines, such as improvement in driveability, economization of fuel, cleaning of exhaust emissions and improved response of fuel supply to varying engine operating condition. BRIEF SUMMARY OF THE INVENTION To cope with these demands, the present invention aims at providing as a first object a slow fuel controlling device for internal combustion engines in which the fuel metered by a slow jet and the air supplied through a slow air bleed are made to be mixed with each other in the state of counter-flows thereby to achieve a fine and uniform atomization of the slow fuel. It is another object of the invention to provide a slow fuel controlling device in which the fuel level of the fuel passage is positioned in the vicinity of the bleed port to improve the response characteristic of fuel supply to achieve a smooth slow speed operation of the engine. BRIEF DESCRIPTION OF THE DRAWINGS The attached Figures in combination show a preferred embodiment of the invention in which: FIG. 1 is a sectional view of a slow fuel controlling device of a down-draft type carburetor; FIG. 2 is a sectional view of a slow fuel controlling device of a horizontal type carburetor; FIG. 3 is an enlarged sectional view of a portion of the carburetor shown in FIG. 1 around a mixing pipe, as observed when the diameter of the fuel passage is increased; FIG. 4 is an enlarged sectional view of a portion of the carburetor shown in FIG. 1 around a mixing pipe, as observed when the diameter of the fuel passage is decreased; and FIG. 5 is a graph showing the engine speed, HC density in the exhaust gases and CO density in the exhaust gases in relation to time as observed during operation of the slow fuel controlling device. DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the invention will be described hereinafter with reference to the accompanying drawings. Referring first to FIG. 1 which is a vertical sectional view showing a slow fuel system of a carburetor, a bypass hole 11 and an idle hole 12 are opened in the vicinity of a throttle valve 2 disposed in an intake passage 1. The cross-sectional opening area of the idle hole 12 is adjustable by means of an adjusting screw 13. A main jet provided at the bottom of a float chamber 3 is adapted to meter the fuel which is then introduced into a main fuel passage 14. A part of the fuel metered by the main jet 4, however, flows into a vertical fuel passage 6 after a metering by a slow jet 5. The fuel passage 6 is communicated at its upper end with a mixing pipe 8 having a plurality of bleed ports 9. A first slow air bleed 7 opens at an upper portion of the mixing pipe 8. Thus, the fuel passage 6 and the first slow air bleed 7 are disposed to oppose to each other in vertical direction. The mixing pipe 8 is communicated with a slow passage 10 through an air bleed port 9, while the slow passage 10 opens at its upper end in a second slow air bleed 15. The lower end of the slow passage 10 is in communication with the bypass hole 11 and the idle hole 12. This slow fuel system operates in a manner stated hereinunder. The opening degree of the throttle valve 2 is small when the engine is operating at a low speed, so that vacuum is generated in an idle hole 12 and in the bypass hole 11. In consequence, fuel and air are sucked through the slow jet 5 and the slow air bleeds 7, 15, respectively. The fuel metered by the slow jet 5 and coming up through the vertical fuel passage 6 is mixed with the air supplied through the first slow air bleed 7 within the mixing pipe 8, and is split into fine streams by the plurality of bleed ports 9 before entering the slow passage 10. The fuel in the gas-fuel mixture is further atomized by the intake air which is introduced through the second slow air bleed 15, and is introduced into the intake passage 1 through the idle hole 12 and the bypass hole 11. In the ordinary carburetor, the difference h of height between the fuel level 17 in the float chamber 3 and the mixing pipe 8 is as large as 12 mm or more, as will be seen from FIG. 1, so that a considerably long time is required for the fuel to come up from the fuel passage 6 into the mixing pipe 8, if the diameter of the fuel passage 6 is selected to be large. FIG. 3 shows in larger scale the section of the carburetor shown in FIG. 1 around the mixing pipe, with a large diameter of the vertical fuel passage 6. The diameter of passage 6 shown in FIG. 3 is larger than that intended in accordance with the present invention in order to illustrate its behavior if sized in accordance with ordinary carburetor practice. During the idling of the engine, the sucked fuel comes up to the level of broken line in the mixing pipe 8 and the central portion of the fuel column is depressed by the air introduced through the first slow air bleed 7. In consequence, the air-fuel mixture flows in the form of two-phase flow with the central portion thereof constituted mainly by air while the fuel constituting the peripheral film, so as to ensure a high stability of engine operation free of fluctuation. Then, as the engine is accelerated, the dynamic pressure of the air induced through the first slow air bleed is increased to depress the fuel in the vertical fuel passage 6 as illustrated by full line. In consequence, the fuel is sucked up in the form of liquid film along the wall of the fuel passage 6. An equilibrium between supply and consumption of fuel is maintained if the engine speed is kept constant. However, as the engine is decelerated to the idle speed, the vertical fuel passage 6 is filled up to the level of broken line before the engine speed is lowered. This causes a time lag of supply of the slow fuel. FIG. 5 shows the engine speed, HC density in the exhaust gases and CO density in the exhaust gases from the engine using the slow fuel system shown in FIG. 1, the relation to time, for each case of small diameter of the fuel passage 6 (shown by full lines) and large diameter of the same (shown by broken lines). When the engine is accelerated from idle speed and then decelerated again to the idle speed, the engine operation mode is smoothly changed to idling after deceleration as shown by full lines, if the diameter of the vertical fuel passage 6 is sufficiently small as in the case of embodiment shown in FIG. 4. However, if the diameter of the vertical fuel passage 6 is large as shown in FIG. 3, the engine speed is reduced down to a level which is considerably lower than the ordinary idling speed and even to a level below a threshold level S for maintaining the idling. In addition, the HC density in the exhaust gases are largely increased as shown by broken line curves. To the contrary, the CO density is reduced as compared with the case of normal idling of the engine. This tells the fact that a misfiring is taking place in the cylinder. Thus, if the diameter of the fuel passage 6 is enlarged, a considerable time lag t is inevitably caused before a steady condition of idling is established after deceleration till the fuel level in the fuel passage 6 is raised to the level of the bleed port 9. During this transient period, the engine may be stalled and the condition of exhaust gases is deteriorated. It is possible to set the idle speed at a higher level, as a countermeasure for eliminating the above described problem. This countermeasure, however, is not recommended partly because the fuel consumption is increased and partly because the level of engine noise is increased. FIG. 2 shows in vertical section a slow fuel system of a carburetor constructed in accordance with another embodiment of the invention. This carburetor is a horizontal type one, in contrast to the down draft type carburetor shown in FIG. 1. In general, the horizontal type carburetor can have a reduced size even with a large-size float chamber 103. The fuel 115 in the float chamber 103 is sucked up through a slow fuel passage 106, after a metering by a slot jet 105, and is mixed with bleed air supplied through a slow air bleed 107, within a mixing pipe 108. The fuel mixed with the bleed air then flows into an intake passage 100 through a bypass hole 111 and an idle hole 112 which open in the vicinity of a throttle valve 102. A reference numeral 113 denotes an adjusting screw for adjusting the flow rate of the idle fuel. Supposing here that the diameter of the fuel passage is as small as 1 mm, a rise of fuel level of about 6 mm is caused by the capillary action of the fuel passage 106 with the engine off. Thus, the fuel can naturally (i.e. with external influences) reach the upper end of the fuel passage 106 if the difference h of height between the lower end of the mixing pipe 8 and the fuel level is selected to be 6 mm or smaller. The reduced diameter of the fuel passage 106 also reduces the area subjected to the dynamic pressure of the air induced through the first slow air bleed, so that the depression of the fuel column by this dynamic pressure is suppressed. FIG. 4 is an enlarged sectional view around the mixing pipe of the carburetor shown in FIG. 1, but constructed of a diameter d in accordance with the present invention, but from the preceding should be recognized as also being representative of the equivalent portion of the FIG. 2 carburetor. Since the fuel level in the fuel passage 6 is high as illustrated, the dynamic pressure of the air introduced through the first slow air bleed acts to raise the fuel in the form of liquid fuel along the wall of the mixing pipe 8. Consequently, the fuel passes the entire surface of the bleed port 9 in the form of two-phase flow and, accordingly, the atomization of the fuel is promoted. The full-line curves in FIG. 5 show the characteristics obtained with a carburetor of this embodiment having the fuel passage of reduced diameter. It will be seen from this Figure that the CO density in the exhaust gases is settled without delay after shifting of the engine operation mode from acceleration to deceleration. This shows that the carburetor has a good response characteristic of fuel supply to the change of state of engine operation. Table 1 shows the result of a test conducted by the present inventors to clarify the relationship between the diameter d of the fuel passage and the rise H of the fuel due to the capillary action. This test was executed at a room temperature using an ordinary gasoline as the fuel. Brass was used as the material for constituting the fuel passage, but it was confirmed that no substantial difference is caused by the use of other metallic material. TABLE 1______________________________________d mm 3 2.5 2 1.5 1 0.5H mm 2 2.4 3 4 6 12______________________________________ The diameter of the slow jet 5 (105) is about 0.4 mm. The above-mentioned diameter d should be greater than this diameter. In either case of the down draft type carburetor shown in FIG. 1 and the horizontal type carburetor shown in FIG. 2, the rate of supply of fuel is changed without delay in response to the change of state of engine operation to ensure a smooth and stable engine operation, by arranging such that the fuel level in the fuel passage is positioned in the vicinity of the bleed port. This arrangement is effective also in the suppression of deterioration of the state of exhaust gas, as well as in the reduction of fuel consumption. Although the invention has been described through preferred forms, it will be clear to those skilled in the art that the described embodiments are not exclusive, and various changes and modifications may be imparted thereto without departing from the scope of the invention. For instance, the invention can be applied to other types of carburetors than described, e.g. a carburetor having a single slow air bleed if the arrangement is such that the intake air is blown against the upper end of the fuel. Also, an equivalent effect is obtained even when the invention is applied to a two-barrel two-stage carburetor having two independent intake passages.

A slow fuel controlling device for a carburetor in which fuel metered by a slow jet is mixed with air induced through a slow air bleed in the form of counter flows and the mixture thus formed is supplied into a portion of the intake passage near a throttle valve, and the diameter of the fuel feed passage is selected to substantially fill said passage with fuel by utilizing capillary action.

FIELD [0001] This relates primarily to the field of oil and gas exploration and production. More particularly, this relates to harvesting energy with a downhole oilfield tool to perform work downhole. BACKGROUND [0002] An appreciable fraction of oilfield services are provided by lowering tools down a well to perform particular tasks. Possible tasks include formation evaluation (e.g. logging in open hole and cased wells), opening and closing of valves, analyzing downhole fluids, taking fluid samples, removal of scale build-up (e.g. in producing wells). Some of the downhole oilfield tools are conveyed with cables of appropriate mechanical strength. Additionally, the cables may carry electrical power to the tools as well provide a communication link. Cables that carry power and provide downhole communication are generally called “wireline” cables. [0003] However, because of cost constraints associated with wireline operations, many downhole applications use more simple cables that do not have electrical capability. These simple cables are typically called “slick line” cables. In slick line applications, the energy required to power the tool once it is down in the well generally comes from batteries that are included with or added to the tool. Nevertheless, the batteries are expensive, occupy a sizable amount of tool space, and are typically not very environmentally friendly. SUMMARY [0004] The present disclosure addresses weaknesses of the prior art described above and others. Specifically, one embodiment provides an apparatus comprising a downhole oilfield system. The downhole oilfield system comprises a conveyance and a downhole tool attached to the conveyance. The downhole tool comprises a work performing module (e.g. for logging and/or fluid analysis, etc.) and a potential energy harvesting device. The potential energy harvesting device may be capable of converting potential energy (including pressure fluctuations) into kinetic energy, electrical energy, or stored energy for later use. In one embodiment, the potential energy harvesting device is configured to convert and store potential energy as a result of lowering the downhole tool into a well. In one embodiment, the potential energy harvesting device comprises a turbine/generator pair. In one embodiment, the generator is electrically connected to a battery. [0005] In one embodiment, the potential energy harvesting device comprises a hollow mandrel having an interior portion and at least one side opening in the mandrel leading to the interior portion. In one embodiment, the turbine is arranged in the interior portion. In another embodiment, the potential energy harvesting device comprises at least one external wheel configured to contact and roll along a well wall, and an energy conversion module operatively connected to the at least one external wheel. The energy conversion module may comprise a generator. In one embodiment, an energy storage module is operatively connected to the at least one external wheel. In one embodiment, the energy storage module comprises a flywheel, and the apparatus may further comprise a belt or chain connecting the at least one external wheel to the flywheel. In one embodiment, the energy storage module comprises a generator and a battery. [0006] In one embodiment, the potential energy harvesting device comprises piezoelectric elements electrically connected to an energy storage apparatus, such as a battery. In one embodiment, the potential energy harvesting device comprises a hollow mandrel having an interior portion, at least one opening in the mandrel leading to the interior portion (the interior portion comprising an inside surface geometry configured to cause pressure fluctuations when fluids pass through the interior portion), and the inside surface comprises the piezoelectric elements. [0007] In some embodiments of the apparatus, the conveyance comprises a slick line, wireline, or coiled tubing. In one embodiment, the work performing module comprises a logging module or a fluid analysis module. [0008] One aspect provides a method comprising moving a downhole oilfield tool through a borehole, harvesting energy from the downhole oilfield tool—the harvesting comprising collecting energy from the moving of the downhole tool through a borehole—and storing the energy collected from the moving of the downhole tool through the borehole. One method further comprising performing work downhole with the stored energy. In one aspect, the work comprises one or more of: logging the borehole, opening/closing a valve, analyzing downhole fluids, and removing scale build. [0009] In one aspect of the method, the harvesting comprises flowing fluids through the downhole oilfield tool, rotating a turbine with the flowing fluids, and driving a generator with the turbine. In one aspect, the flowing comprises one or more of: lowering the downhole oilfield tool through the fluids, and oscillating the downhole oilfield tool through the fluids. In one aspect, the harvesting comprises rolling at least one wheel of the downhole oilfield tool along a wall of the borehole, and converting the rolling motion into a usable, stored energy form. In one aspect, the harvesting comprises rolling a plurality of wheels of the downhole oilfield tool along a cased wall of the borehole. In one aspect, the harvesting comprises rolling at least one wheel of the downhole oilfield tool along a wall of the borehole, and rotating a flywheel with the rolling of the at least one wheel. In one embodiment, the harvesting comprises rolling at least one wheel of the downhole oilfield tool along a wall of the borehole, and rotating a generator with the at least one wheel. In one aspect, the harvesting comprises providing an interior channel in the downhole oilfield tool, flowing fluids through the interior channel, causing flow fluctuations through the interior channel with appropriate surface geometry, generating pressure changes from the flow fluctuations, and converting the pressure changes into electrical energy with an active material. The active material may comprise a piezoelectric material. In one aspect, the flowing comprises lowering the downhole oilfield tool through the fluids and/or oscillating the downhole oilfield tool through the fluids. [0010] One embodiment provides an apparatus comprising a downhole slick line tool system. The downhole slick line tool system comprises a slick line, a slick line tool attached to the slick line, the slick line tool comprising a work performing module and an energy harvesting device. The energy harvesting device comprises a mandrel having a channel therethrough, a turbine on a rod disposed in the channel, a generator connected to the rod, and electrical circuitry between the generator and the work performing module. In one embodiment, the work performing module comprises a formation evaluation device. [0011] One aspect provides a method comprising converting potential energy in the form of an oilfield tool mass suspended above a borehole and subject to a gravitational force into one of: stored, reusable kinetic energy or stored electrical energy; and using the stored, reusable kinetic energy or stored electrical energy to perform a task downhole. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The accompanying drawings illustrate certain embodiments and are a part of the specification. [0013] FIG. 1 illustrates a borehole in cross-section and a downhole oilfield system in partial cross-section. The downhole oilfield system includes an energy harvesting device—in the case of FIG. 1 a turbine/generator pair. [0014] FIG. 2A illustrates the borehole of FIG. 1 in cross-section and another downhole oilfield system in partial cross-section. The downhole oilfield system of FIG. 2A includes a pair of rolling wheels to harvest energy as a downhole tool moves. [0015] FIG. 2B illustrates the borehole of FIG. 1 in cross-section and another downhole oilfield system in partial cross-section. The downhole oilfield system of FIG. 2B includes a pair of angled rolling wheels to harvest energy as a downhole tool moves [0016] FIG. 3 illustrates the borehole of FIG. 1 in cross-section and another downhole oilfield system in partial cross-section. The downhole oilfield system of FIG. 2A includes an active surface for harvesting energy resulting from changes in pressure. [0017] Throughout the drawings, identical reference numbers indicate similar, but not necessarily identical elements. While the principles described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents and alternatives falling within the scope of the appended claims. DETAILED DESCRIPTION [0018] Illustrative embodiments and aspects of the invention are described below. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, that will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. [0019] Reference throughout the specification to “one embodiment,” “an embodiment,” “some embodiments,” “one aspect,” “an aspect,” or “some aspects” means that a particular feature, structure, method, or characteristic described in connection with the embodiment or aspect is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” or “in some embodiments” in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, methods, or characteristics may be combined in any suitable manner in one or more embodiments. The words “including” and “having” shall have the same meaning as the word “comprising.” [0020] Moreover, inventive aspects lie in less than all features of a single disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. [0021] Turning now to the drawings, and in particular to FIG. 1 , one embodiment of a downhole oilfield system 100 is disclosed. The downhole oilfield system 100 includes a conveyance such as a slick line 102 . The conveyance may also comprise coiled tubing, a wireline, or other conveyance. As shown in FIG. 1 , a downhole tool 104 is attached to the slick line 102 . The downhole tool 104 includes a work performing module 106 . The work performing module 106 may include any device for performing work downhole, including, but not limited to a logging device, a fluid analyzer, a descaler, and a mechanical mover (e.g. valve opener). [0022] In some embodiments, the downhole tool 104 also includes a potential energy harvesting device 108 . The potential energy harvesting device 108 may be capable of converting potential energy (which includes pressure fluctuations) into kinetic energy, electrical energy, or stored energy for later use. In one embodiment, the potential energy harvesting device 108 is configured to convert and store potential energy as a result of lowering the downhole tool 104 into a well or borehole 110 . The potential energy harvesting device 108 may take on any form. In the embodiment of FIG. 1 , the potential energy harvesting device 108 comprises a turbine/generator pair. The turbine/generator pair includes at least one turbine 112 (or a plurality of turbines as shown in FIG. 1 ) coupled to a generator 114 . A rod 116 may be common to both the turbine 112 and the generator 114 . Further, in one embodiment, the generator 114 is electrically connected to a battery 118 . The battery 118 may then store energy to perform work (for example by the work performing module 106 ). The battery 118 may therefore be electrically connected to any electrically operated machine. [0023] As shown in FIG. 1 , the potential energy harvesting device 108 may include a hollow mandrel 120 . The hollow mandrel 120 has an interior portion 122 and at least one opening 124 providing for fluid communication between the borehole 110 and the interior portion 122 . In the embodiment of FIG. 1 , there are a plurality of side openings 124 leading into the interior portion 122 , but any other openings may be used. In the embodiment of FIG. 1 , the turbine 112 is arranged in the interior portion 122 . FIG. 1 illustrates the turbine 112 centrally located in the interior portion 122 , but it could also be offset or otherwise arranged. [0024] A mentioned above, there is often a considerable amount of potential energy that is typically lost by conventional downhole tools as they moves from the surface down through a borehole. However, according to principles described herein, methods and apparatus are employed to recover and/or store some of the potential energy associated with movement of the downhole tool 104 . The downhole tool 104 of FIG. 1 is equipped with the potential energy harvesting device 108 that harvests energy as the tool is moved through the borehole 110 . Movement of the downhole tool 104 may be due to the force of gravity. However, in some aspects, movement is generated by imposing an oscillatory up/down motion from the surface, provided the downhole tool is suspended by a conveyance of appropriate mechanical strength. [0025] According to the embodiment of FIG. 1 , harvesting potential energy is accomplished by flowing fluids through the interior portion 122 as the downhole tool 104 traverses the borehole 110 . The openings 124 allow downhole fluids to pass through the interior portion 122 as the downhole tool 104 , and the flowing fluids rotate the turbine 112 . The turbine 112 drives the rod 116 , and the rod 116 drives the generator 114 . The generator may produce electricity that can be used as it is produced or stored by the battery 118 . It will be understood by one or ordinary skill in the art having the benefit of this disclosure that the flowing by the turbine 112 is not necessarily inside the interior portion 112 and can be facilitated simply lowering the downhole tool 104 through the fluids or oscillating the downhole tool 104 through the fluids. The battery 118 may then operate the work performing module 106 , and may eliminate the need for separate battery power or wired power from the surface. Accordingly, the apparatus of FIG. 1 may especially useful for slick line applications. The work performing module may consume energy from the generator 114 or the battery 118 to log the borehole 110 , cause mechanical movement (for example to open or close a valve), analyze downhole fluids, remove scale build, etc. [0026] Alternate embodiment are disclosed in FIGS. 2A and 2B . Similar to the embodiment of FIG. 1 , the embodiment of FIGS. 2A and 2B provide a downhole oilfield system 200 . The downhole oilfield system 200 includes a conveyance such as a slick line 202 . A downhole tool 204 is attached to the slick line 202 . The downhole tool 204 includes a work performing module 206 . The work performing module 206 may include any device for performing work downhole. [0027] The downhole tool 204 also includes a potential energy harvesting device 208 . The potential energy harvesting device 208 is capable of converting potential energy into kinetic energy, electrical energy, or stored energy for later use. As with the embodiments described above, the potential energy harvesting device 208 of FIG. 2A is configured to convert and store potential energy as a result of lowering or moving the downhole tool 204 into (or out of) the well or borehole 110 . In the embodiment of FIG. 2A , the potential energy harvesting device 208 comprises at least one wheel or other rolling members. For example, as shown in FIG. 2A , the potential energy harvesting device 208 includes two external wheels 212 , 213 configured to contact and roll along a well wall 226 , especially a cased wall. The two external wheels 212 , 213 are operatively connected to an energy conversion and/or storage module 216 . The energy conversion and/or storage module 216 may comprise a generator. However, in the embodiment of FIG. 2A , the energy conversion and/or storage module comprises first and second flywheels 220 , 222 . The first external wheel 212 is connected to the first flywheel 220 by a first belt or chain 224 , and the second external wheel 213 is connected to the second flywheel 222 by a second belt or chain 225 . It will be understood by one of ordinary skill in the art having the benefit of this disclosure that any number of external wheels and flywheels may be used, along with any other connection mechanism therebetween. The flywheels 220 , 222 may store the energy until used mechanically, or they may power a generator or other device. [0028] Accordingly, in some aspects, the harvesting potential energy comprises rolling at least one wheel 212 , 213 of the downhole tool 204 along the wall 226 of the borehole 110 , and converting the rolling motion into a usable, stored energy form. In one aspect, converting the rolling motion into a usable, stored energy form includes rolling at least one wheel 212 , 213 of the downhole tool 204 along the wall 226 of the borehole 110 , and rotating the associated flywheel 220 , 222 with the rolling of the at least one wheel 212 , 213 . However, the rolling wheels 212 , 213 , may also rotate one or more generators. [0029] Another embodiment is disclosed in FIG. 3 . Similar to the embodiments of FIGS. 1-2 , the embodiment of FIG. 3 provides a downhole oilfield system 300 . The downhole oilfield system 300 includes a conveyance such as a slick line 302 . A downhole tool 304 is attached to the slick line 302 . The downhole tool 304 includes a work performing module 306 . The work performing module 306 may include any device for performing work downhole. [0030] The downhole tool 304 also includes a potential energy harvesting device 308 . The potential energy harvesting device 308 is capable of converting potential energy in the form of pressure changes into electrical energy for concurrent or later use. As with the embodiments described above, the potential energy harvesting device 308 of FIG. 3 is configured to convert and store potential energy as a result of lowering or moving the downhole tool 304 into (or out of) the well or borehole 110 . In the embodiment of FIG. 3 , the potential energy harvesting device 308 comprises an active material such as piezoelectric elements 330 electrically connected to an energy storage apparatus, such as a battery 118 ( FIG. 1 ). As shown in FIG. 3 , the potential energy harvesting device 308 comprises a hollow mandrel 320 having an interior portion 322 , and at least one opening 324 in the mandrel leading to the interior portion 322 . The interior portion 322 exhibits an inside surface geometry configured to cause pressure fluctuations when fluids pass therethrough, and the inside surface comprises the piezoelectric elements 330 . For example, the inside surface geometry of the interior portion 322 may alternate between increases and decreases in diameter as shown. Changes in internal diameter with a flow therethrough results in pressure fluctuations. The piezoelectric elements convert pressure fluctuations into electrical currents, which can be used immediately to perform work to charge a battery. [0031] Accordingly, in one aspect, the lowering (or raising/oscillating) the downhole oilfield tool 304 through fluids in the borehole 110 causes pressure fluctuations in the interior portion 322 . Pressure fluctuations may be converted by the piezoelectric elements 330 into electrical currents that charge batteries and/or power work from the work producing module 306 . [0032] The preceding description has been presented only to illustrate and describe certain embodiments. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. Many modifications and variations are possible in light of the above teaching. [0033] The embodiments and aspects were chosen and described in order to best explain the principles of the invention and its practical application. The preceding description is intended to enable others skilled in the art to best utilize the principles in various embodiments and aspects and with various modifications as are suited to the particular use contemplated.

Methods and apparatus for harvesting energy while moving a tool through a well are shown and described. The harvested energy can be used by the tool to perform work once it reaches an intended location in the well, or along the way. A considerable amount of potential energy is typically lost by oilfield tools as they move down through a borehole. Methods and apparatus described herein recover and/or store some of the energy during the downward movement of the tool.

BACKGROUND OF THE INVENTION Pneumatic systems are now widely used for out-of-doors or so-called "drive-up" banking in which tellers at indoors teller terminals attend to customers who motor up to out-of-doors customer terminals to do their banking. Typically, these systems employ carriers to transfer money and papers back and forth between the teller and customer terminals, which carriers are driven or drawn by pneumatic pressure through transit tubes interconnecting the terminals. Characteristic of these systems are the large radiused bends in the transit tubes, necessary in order to bring the tubes into the terminals (or otherwise to change their direction) and at the same time to allow the bends to be negotiated by the carriers. One development in indoors banking is to confine the currency and the tellers in one area and the customers in another area, walled off from the first, so that there is no face to face contact between the two. The areas are then interconnected by some sort of communicating system transferring currency and papers between the two. This allows one teller to handle several customers at a time as well as provides additional security. Similar systems may be used for "personal bankers", those who sit at individual desks and handle more than routine transactions. Each may have a "customer" terminal at his desk so that cash or other valuables, instead of kept at his desk, remain in the "back room", as it were, until needed. But use of the typical out-of-doors pneumatic system indoors is defeated by the large radiused tube bends required for the former which make the same prohibitedly costly and awkward in terms of installation space indoors. For practical reasons therefore it is necessary that pneumatic carriers for indoors banking be able to turn, as it were, "square corners". And that in turn requires some kind of transfer arrangement so that the carrier in a typical installation can move both vertically within each terminal and then immediately horizontally through a transit tube beneath the floor which joins the terminal bases at a right or similarly abrupt angle. So far as known, the most pertinent pneumatic systems of this nature are those in U.S. Pat. Nos. 3,419,229; 3,761,039; and 4,084,769. The first of these employs a blower at each end of the transit tube between the terminals and relies wholly upon an opening to the atmosphere at the upper end of the receiving terminal to create a vertical draft, owing to the escaping confluence of the blowers from the transit tube, which both halts the carrier at the receiving terminal and then elevates it in that terminal. This scheme is probably rather uncertain in operation and likely needs some added assistance to halt the carrier in alignment with the receiving terminal and then to elevate it initially (see, for example, U.S. Pat. Nos. 3,512,735 and 3,556,437 to these ends). The other two patents, 3,761,039 and 4,084,769, incorporate elevators which transport the carrier vertically in each terminal before and after its passage through the horizontal transit tube. These latter two arrangements, though assuring location of the carrier with respect to the terminals, tend to lack sufficient lifting ability owing to their use of a single blower and its relatively remote location. This is certainly the case when the carrier is heavily laden unless an out-sized and thus costly blower is used. Hence the chief object of the present invention is an indoors pneumatic system for banking and the like which avoids the foregoing deficiencies and vagaries of the prior art systems as well as incorporates additional novel features which enhance its operation. SUMMARY OF THE INVENTION The invention, broadly speaking, employs a pair of vertical terminals interconnected at their lower ends by a carrier transit tube. Each terminal includes a carrier elevator and a blower, all arranged so that when the carrier is dispatched from the sending terminal, its elevator and the carrier first descend by gravity. The carrier is then propelled from the elevator through the transit tube and onto the elevator of the receiving terminal, all by the blower at the sending terminal. The blower at the receiving terminal thence initially lifts the elevator and carrier at the latter terminal until the effort of that blower is joined with that of the blower of the sending terminal through the transit tube, whereupon the carrier and elevator are lifted to the upper end of the receiving terminal. This cooperation between the two blowers is achieved by a special duct arrangement at each terminal and a number of controls which govern the operation not only of the two blowers to move the carrier and the elevators in the manner just described, but also the operation of a pair of vents atop the terminals which influence the speed of the carrier through the transit tube and the movement of the elevators in the terminals. The carrier itself is preferably but not necessarily of the "captive" type, which is to say that it cannot be removed from either terminal. It is given a sliding cover which opens and closes with a sliding door atop each terminal so that items can be inserted in and removed from the carrier. The door of the sending terminal (and thus the carrier cover) is also integrated into the controls so that closing of that door unleashes the sequence of operations sensing the carrier to the receiving terminal. Other features and advantages of the present invention will become apparent from the drawings and the more detailed description which follows. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat diagramatic side elevation of a pair of interconnected customer and teller terminals according to the invention, certain parts being shown in section. FIG. 2 is a top plan view of the teller terminal of FIG. 1, various parts being broken away to illustrate the interior of the terminal at its upper end. FIG. 3 is a side elevation of the teller terminal of FIG. 2, certain parts being broken away to further illustrate the interior of the terminal at its upper end. FIG. 4 is a side elevation of the lower portion only of the terminal of FIGS. 2 and 3, certain parts being broken away and sectioned to illustrate the details of the special ducting and the action of the blower at that terminal. FIG. 5 is an upper perspective view of one of the carrier elevators employed in the terminals of FIGS. 1-4. FIG. 6 is an upper perspective view of the carrier itself which is transmitted between the terminals of FIGS. 1-4. FIG. 7 is a partial sectional view taken along the line 7--7 of FIG. 6 but with the carrier cover closed and additionally illustrating the teller terminal door and its action upon the carrier cover. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 a customer terminal CT is depicted connected to a teller terminal TT by a carrier transit tube 10 extending horizontally beneath a floor 12. The terminals CT and TT are essentially identical in structure and operation so that only the teller terminal TT is shown in detail and identical reference numerals are used for both terminals except that certain parts will be given the prefix "C" or "T" in order to associate them with the terminal CT or TT, as the case may be. The terminals CT and TT consist essentially of upright sheetmetal elevator enclosures 14, rectangular in cross-section, their lower ends being received into the floor 12 and their upper ends having a cantilevered pair of sheetmetal component enclosures 16. The respective ends of the two enclosures 16 are mounted on the opposing end walls 18 of the terminals CT and TT and open into the enclosures 14 through suitable apertures (not shown) in the end walls 18, the tops of the enclosures 14 and 16 being flush with each other. On the end walls 18 below the enclosures 16 are mounted a pair of electrical boxes 20 and a pair of integral motor-blower units CM, CB and TM, TB, which are simply proprietary vacuum cleaner units and thus relatively small and inexpensive. Two pairs of side walls 22 and another pair of end walls 24, all bolted together and to the end walls 18, as shown in FIG. 2, complete the basic structure of the terminals CT and TT. The bottom walls of the enclosures 16 are apertured and normally closed by circular, elastomeric air valves CV and TV, the latter being opened by solenoids CVS and TVS (only valve TV and solenoid TVS being shown; see FIG. 2) in order to selectively vent the interiors of the enclosures 14 and 16 to the atmosphere. Each pair of enclosures 14 and 16 is then surrounded by an outer housing 26. It will be observed from FIGS. 2 and 3 that the side walls 22 of each terminal CT and TT are formed of two panels 22a and 22b laterally joined by bolts, the bolted edges of the former panels being formed with two vertical interior ribs to provide elevator guides 28. Inward flanges 30 frame the inner faces of the tops of the enclosures 14 and 16 to form door guides for the customer and teller terminal doors CD and TD. The latter doors are flanged sheetmetal panels which embrace the outer faces of the side walls 22 and slide back over the enclosures 16 to reveal the interiors of the enclosures 14. The flanges 30 in turn are spacedly framed by outward flanges 32 bolted to the outer faces of the tops of the enclosures 14 and 16. The flanges 32 mount fixed cover plates 34 (see FIGS. 1 and 3) which both cover the enclosures 16 and overlappingly frame the doors CD and TD. The latter doors are opened and closed by depending, transverse blocks 36, each having a lateral arm 37 for purposes to be described, attached at their upper ends to the under faces of the doors CD and TD and at their lower ends at 38 to drive belts 40 trained over sheaves 42 and driven by reversible door motors CDM and TDM, all disposed in the enclosures 16. The ends of the flanges 32 at the enclosure end walls 24 support control boxes 44, that of the teller terminal TT mounting three push button switches labeled "Send", "Power On/Off" and "Recall", while that at the customer terminal CT mounts a single push button switch labeled "Send". The ends of the transit tube 10, which is rectangular in cross-section, are spigotted into sleeves 46 bolted to and opening into the lower ends of the terminals CT and TT through their end walls 18. The walls of the sleeves 46 are spacedly surrounded by manifolds 48 whose outer ends 50 are secured airtight about the sleeves 46, their inner ends being also bolted airtight to the terminal end walls 18 about the inner ends of the sleeves 46. The manifolds 48 open into the bottoms of the terminals CT and TT through wide but shallow ports 52 through the terminal end walls 18 below the sleeves 46 (see FIG. 4). The top walls of the manifolds 48 are apertured to receive the output of the blowers CB and TB through appropriate flexible connections 54. The side walls of the manifolds 48 are provided with sensors CS and TS, in the form of electric "eyes", which pass through the manifolds 48 and open into the transit tube 10 for purposes to be described. The carrier elevators CE and TE (see FIG. 5), one for each terminal CT and TT, comprise rectangular assemblies of extruded and fabricated aluminum which slidingly closely fit within the housings 14. Each elevator CE and TE includes a pair of side walls 60 inwardly flanged at their upper edges to provide carrier retainers 60a and outwardly flanged at 60b adjacent their upper and lower edges to receive strips of suitable sealing material 62 for engaging the inner faces of the terminal side walls 22. The flanges 60b and strips 62 are centrally interrupted at 64 to accommodate the elevator guides 28 on the terminal side walls 22, the guides 28 also engaging vertical runners 66 on the elevator side walls 60 between the flanges 60b. The floor 66 of each elevator CE and TE is composed of two abutting inner flanges integral with their respective side walls 60 and is ported at 68a and 68b for purposes to be described. The floor 66 is elevated so as to provide a wide shallow tunnel or passageway 70 with the side walls 60 below the floor 66 and the bottoms of the terminals CT and TT. The elevator passageways 70 are generally congruent with the ports 52 in the terminal end walls 18 and open through appropriate reliefs 72 in the elevator front end walls 74 screwed to the elevator end walls 60. The front end walls 74 are apertured above the floor 66 to provide carrier entrances 76, the upper edges of the end walls 74 having inward carrier retaining flanges 78 centrally interrupted at 80 for purposes to be described. The elevator rear end walls 82, having inward top flanges 84, are also screwed to the side walls 60 and form the rear ends of the floor ports 68b. The inner faces of the elevator end walls 82 are covered with thick carrier cushions 86 and the latter are centrally relieved at 88 to communicate with the passageways 70 therebelow through the floor ports 68b, the area of the reliefs 88 being substantially less than that of the carrier entrances 76, also for purposes to be described. When at their lower positions in the terminals CT and TT the elevators CE and TE merely sit upon the bottoms of the enclosures 14, as shown in FIG. 4. When, on the other hand, the elevators CE and TE are at their upper positions in the tops of the enclosures 14, as shown in FIGS. 2 and 3, they are retained by overrunning catches CL and TL which engage the under sides of the elevator floors 66 through reliefs 89 in the elevator front walls 74. The catches CL and TL are released by solenoids CS and TS, the latter and the catches CL and TL being located in the adjacent ends of the enclosures 16 and operating through appropriate apertures in the terminal end walls 18 (see FIG. 3). The elevators CE and TE sequentially receive the single captive carrier C which is essentially a rectangular box cross-sectionally congruent with the transit tube 10. The carrier C comprises fabricated side walls 90, a bottom wall 92 and end walls 94 and 96, all secured by screws. The side walls 90 extend above the end walls 94 and 96 and they and a carrier cover CC are given tongue and groove configurations 98 so that the cover CC may be slid in either direction over the end wall 94 or 96 for access to the carrier's interior. The exterior of each end wall 94 and 96 is provided with a laterally offset bumper 100. As previously mentioned the cover CC is opened and closed by the terminal doors CD and TD. For this purpose the opposite ends of the cover CC are provided with oppositely disposed, longitudinally aligned latches 110 (see FIGS. 6 and 7). Each latch 110 is carried in a slotted aperture 112 in the cover CC and consists of a deep toe 114 and a shallower heel 116, the latter joining the toe 114 to form an upper shoulder 118. A pair of short transverse trunnions 120 extend from the sides of the latch 110 between the toe and heel 114 and 116. The ends of the trunnions 120 lie in shallow recesses 122 along the sides of the slot 112 and are pivotally secured by pillow blocks 124. A bias spring 126 is wound around one of the trunnions 120, one end 126a of the spring 126 being secured to the outer end of the toe 114 and the other end 126b lying in a narrow recess 128 in the cover CC along side the adjacent trunnion recess 122 such that the latch 110 is biased to the position shown in FIG. 7. In that position the toes 114 of the two latches closely abut the inner faces of the carrier end walls 94 and 96 and thus prevent the cover CC from being slid open in either direction. Each of the terminal doors CD and TD is then provided with a pair of depending latch operating pins 130 laterally aligned with the latches 110. When, say, the teller elevator TE with the carrier C approaches its upper position in the teller terminal TT, the carrier door CC is closed. The teller door pins 130 thereupon engage and depress the two latch heels 116, rocking the latches 110 about their trunnions 120 against the springs 126, and thus raising the two latch toes 114 clear of their respective adjacent carrier end walls 94 and 96. The latch toes 114 are thereby raised and when the teller door motor TDM is energized, the door pin 130 adjacent the carrier end wall 94 moves (to the left in FIG. 7) and engages the shoulder 118 of the adjacent latch 110. As the door TD continues to open, that door pin 130 therefore begins to slide open the carrier cover CC. As the latter opens, the depressed heel 116 of the adjacent latch 110 clears the carrier end wall 94 by virtue of one of a pair of slots 132 in the upper edges of the door end walls 94 and 96 for that purpose and then the carrier retaining flanges 78 through their interruption 80. When the door TD and cover CC are fully open, the arm 37 of the block 36 on the door drive belt 40 contacts the latter one of a pair of micro-switches CSW1 and TSW1 in the enclosures 16 of the terminals CT and TT (see FIG. 2) and halts the door motor TDM. When the latter is again energized to reclose the door TD and cover CC, the opposite door pin 130 engages the shoulder 118 of the opposite latch 110 to close the cover CC with the door TD until the door motor TDM is again deenergized by the arm 37 of the drive belt block 36 engaging the latter one of a second pair of micro-switches CSW2 and TSW2 in the enclosures 16 of the terminals CT and TT (see FIG. 2). As the elevator TE and carrier C thereafter descend in the terminal TT, the cover latches 110 are released from the door pins 130 and return to the position shown in FIG. 7, thus latching the cover CC against movement in either direction. It will be understood that the operation of the latches 110 by the customer door CD when the carrier C is in the customer elevator CE at its upper position is identical except in reverse order to that described, the micro-switches CSW1 and CSW2 then energizing and deenergizing the customer door motor CDM. In order to prevent the cover CC from being accidentally pushed so far in one direction or the other relative to the terminal door CD or TD that the door pins 130 are disengaged from the latches 110, the cover CC is provided with a pair of depending stop pins 134 at diagonally opposite corners (see FIG. 6) one of which engages the inner face of its opposite carrier end wall 94 or 96, as the case may be, while the other clears its adjacent carrier end wall 94 or 96 through appropriate notches 136. Overall operation of the system is as follows: Assume that the customer elevator CE with the carrier C therein is in its upper position as indicated in FIG. 1, being held there by the latch CL, and the terminal door CD and thus the carrier cover CC are open. A customer approaches, deposits his transaction in the open carrier C and pushes the "Send" button at the terminal CT. The door motor CDM is thereupon activated in one direction, whereby the carrier cover CC and the door CD are jointly closed in the manner previously described. When the latter are closed, the door motor CDM is deenergized by the switch CSW2 and the latch solenoid CLS is energized, releasing the latch CL. At the same time the air valve solenoid TVS is energized, opening the air valve TV at the teller terminal TT, and the blower motor CM is also energized. The elevator CE and the carrier C thereupon descend by gravity to their lower position in the terminal CT, the carrier cover CC now being latched closed as previously described and the air ahead of the elevator CE being exhausted through the transit tube 10, the terminal TT and the air valve TV. By the time the elevator CE has reached its lower position, the blower CB is up to speed and air therefrom is discharged through its manifold 48 and the port 52 into the passageway 70 beneath the floor 66 of the elevator CE, thence through the floor port 68b and the relief 88 in the rear wall cushion 86 of the elevator CE, and finally against the adjacent end wall 94 (or 96) of the carrier C. Since the door CD and the air valve CV are closed at this time, so that the terminal CT is thereby closed to the atmosphere, the effect of the air is to propel the carrier C from the elevator CE into the transit tube 10, the remainder of the port 68b and the port 68a in the elevator floor 66 increasing the flow of air behind the carrier C from the passageway 70 as the former leaves the elevator CE. When the carrier C passes the sensor CS, the air vent solenoid TVS is deactivated, closing the teller terminal air vent TV, the air ahead of the carrier C in the transit tube 10 thereafter bleeding out through the elevator TE, port 52, manifold 48 and the inactive blower TB at the teller terminal TT. Closing the air vent TV at this time helps control the speed of the carrier C so that, especially when it is heavily loaded, it does not arrive at the terminal TT with too great a velocity and badly jar both its contents and the terminal TT. When the carrier C passes the sensor TS at the latter terminal, the teller blower motor TM is activated and the teller air valve TV is reopened by the solenoid TVS, opening in turn the interior of the terminal TT above the elevator TE to the atmosphere. The carrier C immediately thereafter arrives onto the teller terminal elevator TE through its entrance 76. The blower TB exhausts through the manifold 48 and port 52 into the passageway 70 of the teller terminal TT, the air acting upon the teller elevator floor 66 and the bottom wall 92 of the carrier C through the floor ports 68a and 68b of the elevator TE. Since the blower CB is still operating, its pressure through the transit tube 10 acting upon the carrier end wall 94 (or 96) prevents the carrier C from being dislodged from the elevator TE by air from the blower TB acting upon the carrier C through the relief 88 in the teller elevator cushion 86 since that relief 88, as previously noted, is of substantially less area than that of the entrance 76 of the teller elevator TE. The air from the blower TB therefore initially lifts the elevator TE and carrier C up the terminal TT until, as the adjacent mouth of the transit tube 10 is uncovered, the air from the blower CB joins in and the air from both blowers CB and TB together raise the elevator TE and carrier C to their upper position in the terminal TT, whereupon they are retained by the latch TL. The movement of the latch TL as it is overrun by the elevator TE thereupon turns off both blower motors CM and TM and recloses the teller air valve TV. Simultaneously a time delay circuit, of about two seconds duration, is activated and upon expiration activates in turn the terminal door motor TDM to open the teller door TD and thus the carrier cover CC in the manner previously described, the switch TSW1 thereafter deactivating the door motor TDM. The reason for the delay in the opening of the teller door TD is to give the blower TB time to wind down so that when the teller door TD is opened a blast of air is not forthcoming. The entire system is then "at rest." When the teller has completed the transaction he pushes his "Send" button, the entire sequence is repeated in the reverse order to that just described until the elevator CE and carrier C are once again at their upper position in the customer terminal CT and the door CD of the latter and the carrier cover CC are open to the customer. Should the teller wish to recall the carrier C from the terminal CT, he pushes the "Recall" button which then has the same affect as if a customer had pushed the "Send" button at the terminal CT. The actual electrical circuitry by which the foregoing "logic" or sequences of operation are accomplished is quite conventional and fully within the competence of those ordinarily skilled in the art to provide. Because of this and because that circuitry is not part of the invention it need not be further described. Various modifications of the system as set forth will also be apparent to those skilled in the art so that, though the invention has been described in terms of a particular embodiment, being the best mode known of carrying out the invention, it is not limited to that embodiment alone. Instead, the following claims are to be read as encompassing all adaptations and modifications of the invention falling within its spirit and scope. Furthermore, when reading those claims it should be noted that the terms "leading" and "trailing" therein, when applied to the elevators CE and TE, refer to their respective ends 74 and 82, and, when applied to the carrier C, refer to its end walls 94 or 96 depending upon in which direction the carrier C is being transmitted between the terminals CT and TT.

A pneumatic system for banking consists of a pair of upright customer and teller terminals joined at right angles at their lower ends by a carrier transit tube. Each terminal includes a carrier elevator, a blower and a special ducting such that while only one blower propels the carrier from the sending to the receiving terminal both blowers are used to raise the elevator and carrier at the receiving terminal. Air valves at each terminal influence the movement of the carrier, and various controls initiate the sequence of operations by which the carrier is transferred between the terminals.

TECHNICAL FIELD [0001] The present invention relates to a panel system which may be installed in a building to form, for example, a curtain wall. [0002] The invention also relates to a building incorporating a panel system, a kit of parts for installing a panel skin in or on a building, and a method of installing in or on a building such a kit of parts. BACKGROUND OF THE INVENTION [0003] It is popular for a building to have a curtain wall of glazing panels in order to create a light, environmentally-controlled enclosed space for greater public amenity and security. For example, the facade of an office building may be two or more storeys high, and may be given an exterior curtain wall of glazed panels. The glazed panels are usually rectangular and abut against one another and are formed into rows and columns. They need to be supported in position. A metal framework of tensioned steel cables or rods, quite often incorporating bracing cables, is frequently positioned behind the glazed panels and forms a network extending vertically and horizontally, and also has a significant depth perpendicular to the glazed panels in order to be able to resist bowing or flexing of the glazed panels such as may be caused by wind pressure. The front face of the structural framework has clamps or feet which project forwards and are fastened through or bonded to the wall of glazed panels. [0004] Considering a rectangular array of rectangular glazed panels, the vertical and horizontal joints between the panels will resemble a grid, and it is usual for the structural framework to support the glazed panels at or near to the intersections or nodes of the grid. [0005] Usually, the weight of each glazed panel is individually transferred back to the structural framework, so that the bottommost panel in a particular column of the glazed panels does not have to bear the weight of the entire column. [0006] A structural framework of this general type is the Pilkington Planar (TM) system produced by Pilkington Plc. [0007] Such structural framework can be visually intrusive particularly if it is linked together horizontally as well as vertically and if trusses are incorporated. [0008] More recently, more compact structural support apparatus has been proposed. For example, U.S. Pat. No. 6,658,804 discloses a self-bearing flexible curtain wall system. A glass curtain wall comprises rectangular glass panels arranged as a matrix or array of columns and rows. The weight of the glass panels is transferred down through the stack of panels in a particular column. Structural stability is provided by positioning a plurality of vertical metal cables behind the glass curtain wall. The feet of the metal cables are secured into the sill of the building, and the tops of the cables are secured to the frame of the building. The metal cables are tensioned. Each metal cable carries a plurality of anchor fixtures which are free to slide up and down the cable. Each anchor fixture projects forwards into the glass wall at a node of the grid of the glass wall where a vertical joint between the panels intersects a horizontal joint. In this way, the anchor fixtures provide stability to the glass wall in the direction perpendicular to the plane of the glass wall without actually carrying the weight of the glass panels. [0009] The glass panels can flex relative to one another in a vertical direction and a horizontal direction, and the metal cables and their anchor fixtures can move backwards and forwards in order to accommodate this flexing. SUMMARY OF THE INVENTION [0010] According to a first aspect of the present invention, there is provided a panel system comprising: [0011] an array of panels positioned side by side to form a panel skin; [0012] a plurality of fibre linear tensile elements which are generally parallel and extend from a first periphery to a second, opposite periphery of the panel skin; and [0013] a plurality of clamping devices which are clamped to the fibre linear tensile elements and are fixed to the panel skin. [0014] By using fibre linear tensile elements rather than metal cables, there is the benefit that, in use, there will be less variation in the tension of the supporting structure (the fibre linear tensile elements) resulting from thermal expansion and contraction. This is because of the lower coefficient of linear expansion of the fibre linear tensile elements. [0015] In the case of glazed panels, the fibre linear tensile elements will not damage (e.g. abrade or chip) the panels if they come into contact with them during installation of the panel system in a building. [0016] Fibre linear tensile elements made of polymeric material are non-conductive compared with steel alloy rods or cables, and thus electrolytic corrosion or surface oxidation of the fibre linear tensile elements will not occur. [0017] With the panel system of the present invention, the clamping devices are supplied clamped into position onto the fibre linear tensile elements. The clamping devices will usually be made of metal but, because of the resilient nature of the material of the fibre linear tensile elements, the clamping devices will not permanently produce localised damage at the clamping positions on the fibre linear tensile elements. This means that, if during installation of the panel system it is necessary to adjust the positioning of some of the clamping devices before the panels are fitted, there will be no significant, aesthetically-unattractive marking of the surface of the fibre linear tensile elements at the old positions of the clamping devices. Metal clamping devices for clamping onto a metal cable are known to leave permanent markings (indentations) at the old clamping positions. [0018] When installed, the panel skin may undergo a visibly-noticeable amount of flexing when, for example, it is exposed to wind loading. For example, an observer standing in front of a glass curtain wall which is glazing an atrium may easily notice the flexing caused by wind loading because the reflected images (of distant objects) in the glazed panels will appear to vary in a noticeable way. The degree of this flexing can be increased or reduced depending on the tension applied to the fibre linear tensile elements and on their fibre construction. [0019] The panel system is an architectural building system, and it may be used to provide a roof for a building, in addition to the more usual likely use of providing a wall for a building. The wall will often be planar, but the wall could be curved. This may be achieved by arranging for the curvature of the wall to occur in a direction transverse to the direction of the mutually-parallel fibre linear tensile elements. In relation to the panels, instead of having the usual planar configuration, the panels may be bowed so that each matches the local curvature of the curved wall. Thus, each panel may be convexely or concavely curved in one direction (the direction of the width of the wall). If the wall is sinuous or serpentine, some panels will be convex, some panels will be concave, and some panels might even be convex and concave at respective sides of a particular panel. [0020] We expect that the most commercially-popular form of the invention will be for the panels to be glazing panels, such as double-glazed units for an exterior curtain wall, or single-glazed units for an interior wall or ceiling such as in an office or hotel atrium. [0021] The fibre linear tensile elements and the clamping devices function together to act as a support structure for the panel skin, and they will usually be positioned behind the panel skin rather than in front of the panel skin, in relation to what is the usual viewing direction. [0022] It will usually be desirable for the fibre linear tensile elements to be as close as possible to the panel skin, so as to make less visually-intrusive the way in which the panel skin is supported. The clamping devices serve to space the fibre linear tensile elements from the panel skin, and a desirable spacing distance between each fibre linear tensile element and the adjacent surface of the panel skin is a gap size of 0.5 to 6 cm (more preferably, 0.5 to 5 cm, or 0.5 to 4 cm, or 0.5 to 3 cm, or 0.5 to 2 cm). Instead of the lower limit of the gap size being set at 0.5 cm, it could be set at a slightly bigger value such as 1, 1.5 or 2 cm for practical reasons, such as facilitating cleaning of the panels. [0023] Each fibre linear tensile element may have a structural core of (polymer) filaments with the core usually being surrounded by a protective sheath. The core may be formed by starting with a textile yarn of parallel filaments. A plurality of the yarns are twisted to make a wire and then a plurality of the wires are laid to make a strand. Then a plurality of the strands are laid in layers to make the core. As an alternative to this stranded or wire-lay construction, the core might be formed by braiding the filaments or by positioning the filaments to be generally parallel to the longitudinal axis of the fibre linear tensile element. [0024] The sheath may be braided or woven and may be of a different polymer material to that of the structural core. The sheath can serve to protect the structural core from the clamping forces applied by the clamping devices, because the material of the sheath is likely to be more resilient than the material of the core. Thus, if a clamping device needs to be unclamped, moved to a new position and then reclamped, the sheath material at the old clamping position will resiliently spring back to its original shape without leaving any significant visual indication of the old clamping position. [0025] The panel system will, in use, have a natural damping characteristic that depends on the tensioning of the fibre linear tensile elements. It will also depend on the characteristics of the particular plastic (polymeric) material used for the structural component of each fibre linear tensile element and its diameter. A panel skin that is oscillating will also be damped by air resistance in proportion to its surface area. [0026] It will be usual for each fibre linear tensile element to carry a plurality of the clamping devices forming an array of connection nodes between the fibre linear tensile elements and the panel skin. The panel skin may be scaled in size and shape in order to suit the particular commercial application. [0027] With the panel system of the present invention, the clamping devices are supplied clamped in their correct positions onto the fibre linear tensile elements. Done away from the building site, in the clean and controlled conditions of for example a factory, operatives can be trained to be highly skilled, and can accurately position the clamping devices on the fibre linear tensile elements. This saves time on the building site, and removes the element of uncertainty of having to rely on the installers at the building site to position the clamping devices with the risk that time and effort might be consumed in their having to repeatedly adjust the positions of the clamping devices during the installation process. [0028] Usually, each panel is generally rectangular. Quite often, the panels will be of the same size. More complicated alternatives to rectangular panels can be envisaged, such as a panel skin formed by tessellating hexagonal, pentagonal or square panels, or by tessellating combinations such as octagonal panels with square panels. [0029] In the preferred embodiment, the panels are positioned in a matrix-like formation to form the panel skin, with columns of panels and rows of panels which are generally perpendicular to the columns of panels; and the fibre linear tensile elements are generally parallel to the columns of panels. By positioning the fibre linear tensile elements in this way, it is easier to make them less visible compared with alternative possibilities such as the fibre linear tensile elements extending diagonally across the columns. [0030] Preferably, the fibre linear tensile elements extend along respective joints between adjacent columns of the panels. For example, the fibre linear tensile elements can be made less noticeable by filling the joints between the panels with sealant, particularly a sealant of a dark colour such as black, and by positioning the fibre linear tensile elements in close alignment with the sealant. In relation to a panel skin forming a curtain wall, the sealant may be of the weatherproof type. [0031] The fibre linear tensile elements may be given a particular colour and/or texture, e.g. they may be coloured black to be less visible. Thus the black colour of the fibre linear tensile elements may supplement the black colour of the sealant, in order to assist in making the fibre linear tensile elements less visible. [0032] In the preferred embodiment, each clamping device is fixed to at least two adjacent panels of the panel skin. For example, four panels may be clamped by gripping respective panel corners at a junction point (connection node) of the panel array. [0033] We expect that the most popular use of the panel system will be when the panel skin is a wall, such as an (exterior) curtain wall. [0034] In the preferred embodiment, each clamping device has a bracket which projects into the panel skin between the panels and has an upwardly-facing seat on which sit one or more of the panels. [0035] Thus, the weight of the panel(s) above the clamping device is carried by the clamping device, and transferred to the fibre linear tensile element to which the clamping device is clamped. The weight is not carried (or is only minimally carried) by the panel(s) below the clamping device in the wall. Thus the wall is not of the self-bearing weight type, and individual panels may be removed without compromising the surrounding skin structure. [0036] There is no need to provide each panel with a structural frame around its perimeter for the purpose of transferring the weight of the overlying panels to the underlying panels. Thus, for a glazed panel, the glazed area right up to the perimeter of the panel remains visible. Thus, the viewer of a curtain wall made of glazed panels will be presented with a wall of glazing, rather than a wall which is disfigured by unsightly structural frames incorporated in the panels. [0037] Preferably, two of the panels sit on the seat of the clamping device. For example, the bracket has an upwardly projecting divider splitting the seat into two seat portions on which respective panels sit. Thus, at a particular connection node in a curtain wall, the bottom right-hand corner of the left upper panel may sit on one seat portion, and the bottom left-hand corner of the right upper panel may sit on the other seat portion. [0038] Preferably, the bracket has a downwardly-facing guide which locates a top edge portion of the or each of one or more of the panels. [0039] The bracket may comprise a flange, and the upper surface of the flange may provide the seat and the lower surface of the flange may provide the guide, with the thickness of the flange defining the desired gap size of the horizontal joint between the upper and lower panels held in position by the clamping device. [0040] Preferably, two of the panels are located in position in the panel skin by the guide. For example, the bracket has a downwardly-projecting divider splitting the guide into two guide portions which locate respective panels. The top right-hand corner of the left lower panel at a particular connection node of the wall, and the top left-hand corner of the lower right panel, may be located respectively against the two guide portions. [0041] The upper and/or lower divider may define the desired gap size of the vertical joint between the left panels and the right panels held in position by the clamping device. [0042] In the preferred embodiment, the clamping device has a back plate at the rear of the bracket and a removable front plate at the front of the bracket, and the front plate is secured in position by releasable fastener(s) and clamps a plurality of the panels between the front and back plates. [0043] The fastener(s) enable a sufficiently large clamping force to be applied to securely hold the panels in position at the connection node provided by the clamping device. Gaskets may be interposed between the front and back plates and the panels. [0044] During installation of the wall, the front plates may initially be left off the clamping devices. The installer may face the generally vertically-positioned and fully tensioned fibre linear tensile elements and may present up the panels. After a particular clamping device has received all of its panels and any necessary corrections have been made to their alignment, its front plate may be fitted to securely clamp the panels in position. In this way, the panel wall may be built up, usually working upwards from the bottommost row of panels. [0045] Usually, the or each fastener will be adjustable (e.g. a bolt) so that the clamping force is variable and may be set at a desired value. [0046] In the preferred embodiment, the front and back plates are wider than the bracket, and the fasteners are located beyond respective lateral edges of the bracket and preferably extend from the back plate forwardly into releasable engagement with the front plate. [0047] This enables the bracket (e.g. flange) to be made substantially the same thickness as the shank of each fastener (e.g. bolt) as there is no need to provide an aperture in the bracket for the fastener which would require bracket material to be left above and below the aperture in order to avoid weakening the seat (and guide) of the bracket. [0048] In the preferred embodiment, the clamping device includes locking arms which project through the panel skin adjacent to the bracket for holding the panels in position in the absence of the front plate. [0049] For example, during installation of the curtain wall, the locking arms may be used to gently hold the panels in place until they are clamped in position by fitting the front plate. [0050] The locking arms are usually positioned above and below the back plate (e.g. two above and two below) so that there is one locking arm for each of the four panels usually fixed to the clamping device when building up the curtain wall. [0051] Each locking arm may be detachable from the rest of the clamping device so that, when the front plate has been clamped into position, the locking arms may be removed before sealant is applied to the inter-panel joints. [0052] Each locking arm may comprise a shank and a head at the distal end of the shank. Preferably, the head is rotatable (e.g. relative to the shank, or the shank and head are integral and rotate together relative to the part of the clamping device into which the shank is inserted) so that the head can be aligned along the inter-panel joint when offering up a panel to the clamping device, and the head can then be rotated to extend over the front face of that panel to hold it in position. [0053] In the preferred embodiment, each clamping device has a duct through which passes one of the fibre linear tensile elements, and the duct includes means for clamping the fibre linear tensile element. [0054] For example, the clamping means is releasable for unclamping the clamping device from its fibre linear tensile element. The releasable nature of the clamping means permits adjustment of the positioning of the clamping devices on the fibre linear tensile elements during the installation process in a building, e.g. to ensure that all clamping devices in a particular row are aligned prior to fitting the panels. [0055] In the preferred embodiment, the duct comprises first and second duct portions, the clamping means is provided on inner surfaces of the duct portions, and the duct portions are adjustable relative to one another to permit the clamping means to release the fibre linear tensile element. [0056] For example, wedge- or cam-like projections may be provided on the inner surfaces which engage with the fibre linear tensile element and prevent the clamping device from moving in either direction along the fibre linear tensile element. By unclamping and then reclamping, it is possible to adjust the grip position. The duct will usually be split longitudinally to form the duct portions. [0057] In the preferred embodiment, the first duct portion comprises a channel portion and the second duct portion comprises a cover plate which closes the channel portion and is releasably secured to the channel portion by fastener(s). The first duct portion may have a generally U-shaped duct cross-section. This duct portion may be integral with the back plate or bracket mentioned above. [0058] A plurality of the fasteners (e.g. two on each side of the cover plate) may be tightened up until the cover plate abuts against the channel portion, so that a predetermined maximum clamping force cannot be exceeded by over-tightening the fasteners. [0059] In order to reduce unwanted twisting of the clamping device on the fibre linear tensile element, the length of the duct is preferably at least twice (preferably at least three times) the height of the back plate (measured along the direction of the fibre linear tensile element). [0060] Also, the width of the back plate may be plus or minus 30% (or 20%, or 10%) of the length of the duct, so that the clamping device has a cross-like appearance when viewed from in front of or behind the panel skin. [0061] In the preferred embodiment, the panel system further comprises first and second termination devices at respective ends of each fibre linear tensile element for securing the fibre linear tensile element to static building components. [0062] For example, one termination device may be fitted into a floor slab at the bottom of a wall and the other may be fitted to a structural frame at the top of the wall. [0063] Preferably, each termination device comprises a static anchor portion, a movable portion secured to the respective end of the respective fibre linear tensile element, and an adjustment mechanism for adjusting the position of the movable portion relative to the static anchor portion along an adjustment axis generally aligned with the fibre linear tensile element. [0064] One or both of the termination devices may be used to tension up the fibre linear tensile element. The two termination devices may then be operated in synchronism in order to adjust the positioning of the clamping devices of that fibre linear tensile element without altering its tension. This may be necessary, for example, when installing a curtain wall, because it may be apparent after the initial tensioning up of all of the fibre linear tensile elements that a particular fibre linear tensile element's clamping devices are not aligned correctly with those of the neighbouring fibre linear tensile elements. [0065] For example, a laser line may be projected along a particular row of clamping devices in order to check whether they are levelly aligned. [0066] In the preferred embodiment, at least one of the fibre linear tensile elements includes a longitudinal monitoring filament which is connectable to monitoring apparatus arranged to monitor the tensile loading of the or each such fibre linear tensile element. [0067] The monitoring filament may be embedded along the core (rather than in any sheath) of the fibre linear tensile element, preferably along the central axis. It can be used to raise an alarm if the originally-set tension drops below a threshold value. [0068] In the preferred embodiment, the longitudinal monitoring filament is an optical fibre. [0069] The optical fibre may be incorporated at the time of manufacture of the fibre linear tensile element. The monitoring apparatus may shine a light along the optical fibre and monitor for characteristic changes as the tension applied to the fibre linear tensile element (and thus to the embedded linear optical fibre) varies during use. [0070] Preferably, each fibre linear tensile element includes such a longitudinal monitoring filament. [0071] For example, the monitoring filaments could be connected together in series by the monitoring apparatus. Preferably they are connected in parallel to the monitoring apparatus so that the apparatus can individually monitor each fibre linear tensile element. Thus an alarm signal may identify any fibre linear tensile element where a change has occurred. [0072] Each monitoring filament will usually run the full (tensioned) length of the fibre linear tensile element. For example, there may be untensioned end portions above and/or within the top termination device holding the fibre linear tensile element and below and/or within the bottom termination device, and these end portions may be unpicked to expose the optical fibre embedded at the centre of the core of the fibre linear tensile element. The exposed ends of the optical fibre can be connected to the monitoring apparatus to form an optical monitoring circuit. [0073] In some embodiments, where it is desirable for there to be less flexing of the panel skin, elongate structural supports are fixed to the clamping devices and extend transversely between the fibre linear tensile elements. Thus, the fibre linear tensile elements are given additional stability for limiting deflection of the panel skin. The structural supports may be stiffening spars or other rigid elongate members. [0074] In many such installations, the structural supports are generally parallel to the rows of panels. For example, the structural supports extend along respective joints between adjacent rows of the panels. [0075] Conveniently, the structural supports are connected to rear portions of the clamping devices. For example, the connection may be to the duct and/or back plate of the clamping device. [0076] According to a second aspect of the present invention, there is provided a building incorporating a panel system according to the first aspect of the present invention, wherein the fibre linear tensile elements are secured to static components of the building and are tensioned. In most applications, there will be uniform tensioning of the set of fibre linear tensile elements. [0077] In many installations, the panel system is positioned such that the panel skin is a curtain wall. [0078] According to a third aspect of the present invention, there is provided a kit of parts for installing a panel skin in or on a building, comprising: [0079] a plurality of panels positionable side by side as an array to form the panel skin; [0080] a plurality of fibre linear tensile elements each having a length sufficient to extend from a first periphery to a second, opposite periphery of the panel skin; and [0081] a plurality of clamping devices which are clampable to the fibre linear tensile elements and are configured to receive and fix in position the panels of the panel skin. [0082] Preferred aspects are as discussed above in relation to the first aspect of the present invention. [0083] Usually, the panel skin is a rectangular array made up of rectangular panels. For an array of X columns and Y rows of panels, where the fibre linear tensile elements are to be aligned with the columnar grid lines of the array, there will usually be (X−1), X or (X+1) fibre linear tensile elements depending on whether both, 1 or 0 respectively of the outer side edges of the outermost columns of the panel skin are fixed to the building rather than to respective fibre linear tensile elements. [0084] Usually, there will be (Y−1), Y or (Y+1) clamping devices clamped to each fibre linear tensile element depending on whether both, 1 or 0 respectively of the top and bottom edges of the top and bottom rows of the panel skin are fixed to the building rather than to the fibre linear tensile elements. [0085] Each clamping device is a panel mounting node of the grid of the panel array. The clamping devices along the periphery of the grid will grip two panels (if on an edge of the grid) or one panel (if at a corner of the grid). The clamping devices inside the periphery will each grip four panels. [0086] In many building installations, the pattern of spacing of the clamping devices along a fibre linear tensile element will be the same for all the fibre linear tensile elements. If the panels are of a uniform size, the spacing will be uniform along each fibre linear tensile element. [0087] According to a fourth aspect of the present invention, there is provided a method of installing in or on a building a kit of parts in accordance with the third aspect of the present invention, the method comprising: [0088] securing the fibre linear tensile elements at their ends to static components of the building and tensioning the fibre linear tensile elements, such that the fibre linear tensile elements are generally parallel; and [0089] fixing the panels to the clamping devices as an array forming a panel skin. [0090] Preferably, the panel skin is planar and, prior to fixing the panels, alignment of the clamping devices into rows transverse to the fibre linear tensile elements is checked by projecting a laser along each row and any clamping device in that row that is out of alignment is unclamped from its fibre linear tensile element and reclamped at an improved alignment position. Alternatively, all clamps on a particular fibre linear tensile element may be repositioned by simultaneous adjustment of its top and bottom terminations. [0091] Alternatively, a laser level may be used to check the height of individual clamping devices. [0092] In the preferred embodiment, for a predetermined desired deflection in response to a predetermined loading of the panel skin, the actual deflection under the predetermined loading is measured and the tensioning of the fibre linear tensile elements is adjusted until the actual deflection substantially equals the desired deflection. The deflection may be measured at a point of envisaged maximum deflection (e.g. the centre of the panel skin) in response to a loading that, for example, simulates a predetermined wind loading. [0093] In practice, we have found that the tensioning necessary to keep the deflection below an acceptable threshold value has the effect of making the panel system naturally damped (self damped) in terms of amplitude and frequency. BRIEF DESCRIPTION OF THE DRAWINGS [0094] Preferred non-limiting embodiments of the present invention will now be described with reference to the accompanying diagrammatic drawings. [0095] FIG. 1 is a perspective view of a building showing an early stage of a method in accordance with the present invention of installing a panel system on the building. [0096] FIG. 2 is a perspective view showing a later stage of the installation method. [0097] FIG. 3 is a perspective view showing, broken at the middle, a fibre linear tensile element of the panel system of FIG. 1 with its upper and lower termination devices. [0098] FIG. 4 is a perspective view of the fibre linear tensile element of FIG. 3 showing it installed at its upper end. [0099] FIG. 5 is a perspective view of the fibre linear tensile element of FIG. 3 showing it installed at its lower end. [0100] FIG. 6 is a rear perspective view of a connection node of the installed panel system of FIG. 2 . [0101] FIG. 7 is an exploded front perspective view of a clamping device shown in FIG. 6 . [0102] FIG. 8 is an exploded rear perspective view of the clamping device of FIG. 7 . [0103] FIG. 9 is an exploded view similar to FIG. 7 but omitting the front plate, gaskets and fasteners. [0104] FIG. 10 is a front elevational view of the clamping device of FIG. 9 , showing it installed on its fibre linear tensile element. [0105] FIG. 11 is a perspective view of a building showing an early stage of a method in accordance with the present invention of installing a second embodiment of a panel system in a building. [0106] FIG. 12 is a perspective view showing the completion of the installation method of FIG. 11 . [0107] FIG. 13 is a perspective view of a building showing a third embodiment, wherein two panel systems in accordance with the present invention are installed spaced apart to provide a thermal buffer therebetween. [0108] FIG. 14 is a perspective view of a building incorporating a fourth embodiment of a panel system in accordance with the present invention and showing how the condition of the panel system may be remotely monitored. [0109] FIG. 15 is a perspective view of a panel system in accordance with a fifth embodiment of the present invention wherein the panel system is provided as a roof of a building. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0110] In relation to the first embodiment of the present invention shown in FIGS. 1-10 , a building 1 comprises floor slab 11 , a roof 12 and intermediate floors 13 supported on columns 14 . The illustrated front face of the building is flat and is having a panel system in accordance with the present invention fitted thereto. The end objective is to fit a glazed curtain wall 80 to the front face of the building. [0111] The panel system comprises fibre linear tensile elements 2 , clamping devices 3 and glazing panels 4 . Additionally, each fibre linear tensile element 2 has upper and lower termination devices 5 , 6 to enable it to be attached to the building 1 . [0112] As shown in FIGS. 3-5 , each termination device 5 , 6 comprises an anchor bracket 51 , 61 which is fixed to the building 1 and an end termination 52 , 62 which is fixed to the end of the fibre linear tensile element 2 . An adjustment nut 53 , 63 enables the position of the end termination 52 , 62 to be varied relative to the static position of the anchor bracket 51 , 61 . [0113] The front face of the building has been designed to receive a rectangular matrix of square glazing panels 4 arranged into rows and columns. The fibre linear tensile elements 2 , clamping devices 3 , and upper and lower termination devices 5 , 6 provide a support structure for the glazing panels 4 . [0114] The design is such that a fibre linear tensile element 2 is to be positioned behind each inter-panel joint between adjacent vertical columns of the panels, and also at the left end and right end of the curtain wall. [0115] In a factory away from the building site, the appropriate number of fibre linear tensile elements 2 are produced with the correct lengths based on the vertical separation between the floor slab 11 and the roof 12 . Each fibre linear tensile element 2 also has fitted to it the appropriate number of clamping devices 3 at the correct positions along its length, and the end terminations 52 , 62 of the upper and lower termination devices 5 , 6 . [0116] The pre-prepared fibre linear tensile elements 2 are then delivered to the building site, such as on the pallet 71 illustrated in FIG. 1 . [0117] The anchor brackets 51 are fitted under the front lip of the roof 12 along the front face of the building. The regular spacing between the anchor brackets 51 corresponds to the width of the glazing panels 4 . [0118] Similarly, the lower anchor brackets 61 are fitted along the front edge of the floor slab 11 with a uniform spacing corresponding to the width of the panels 4 . [0119] Note that, for the sake of clarity, not all of the anchor brackets 51 , 61 are individually labelled in the figures. [0120] Then, starting at the right-hand end of the curtain wall as shown in FIG. 1 , the pre-prepared fibre linear tensile elements 2 are erected. In FIG. 1 , most of the erection operation has taken place. In relation to the leftmost fibre linear tensile element 2 A, it is shown being lifted using an electric winch 72 which has its winch cable 73 attached to the upper end termination 52 . The end termination 52 is fixed to the anchor bracket 51 by using nut 53 . At the bottom end, the end termination 62 is fitted to its anchor bracket 61 by using the nut 63 . Thus the fibre linear tensile element 2 A is installed in position, next to the already-installed fibre linear tensile element 2 B. [0121] As shown for fibre linear tensile element 2 B, the height of the first clamping device 3 B 1 is checked with a laser level 74 . If necessary, the adjustment nuts 53 , 63 at the top and bottom ends are used to move the fibre linear tensile element 2 B up or down, as required, to position the clamping device 3 B 1 at the correct height for the curtain wall. Then, the adjustment nuts 53 , 63 are used to tension up the fibre linear tensile element 2 B without significantly altering the height of the clamping device 3 B 1 . [0122] Now referring to FIG. 2 , the installation method continues with upper and lower glazing profiles 75 , 76 being installed just in front of the anchor brackets 51 , 61 along, respectively, the undersurface of the front lip of the roof 12 and the front edge of the floor slab 11 . [0123] The glazing panels 4 are brought to site and are installed in position using an installation vehicle 77 which has an articulated arm at the end of which are glazing suction pads. Each glazing panel 4 is a double-glazed unit of two glass sheets with a perimeter gasket and a (front) finishing plate. For a particular column of the curtain wall, the bottommost glazing panel 4 is inserted into position with its lower edge fitted into the lower glazing profile 76 . The two upper panel corners are gripped by the first clamping devices 3 A 1 , 3 B 1 of the adjacent two fibre linear tensile elements 2 A and 2 B using the clamping technique that will be described in more detail hereinafter. The next panel 4 in the column is then lifted into position, and its bottom corners are fixed to the clamping devices 3 A 1 , 3 B 1 and its top corners are fixed to the clamping devices 3 A 2 and 3 B 2 . The process is then repeated until all of the panels 4 in the particular column have been installed, with the top edge of the topmost panel being fitted into the upper glazing profile 75 . [0124] Vertical and horizontal rear gaskets are then installed along the inter-panel joints. A workman is shown in FIG. 2 installing a rear vertical gasket 78 . A workman 79 then injects sealant into the inter-panel joints of the front face of the completed curtain wall 80 . [0125] If the (maximum) deflection of the curtain wall 80 out of its plane exceeds a predetermined threshold value under a particular (wind) loading, the tensioning of the fibre linear tensile elements 2 may be increased using the adjustment nuts 53 , 63 until the deflection has been reduced to an acceptable value. [0126] Referring now to FIGS. 3-5 , the fibre linear tensile element 2 is shown as having a cylindrical core 21 of polymer filaments or fibres which provide the structural or tensile strength. Exemplary materials include aramid, LCP (such as Vectran™) or PBO (such as Zylon™). [0127] The fibre linear tensile element 2 includes a cover or sheath 22 which is made of, for example, polyester and which may be coloured or patterned to suit the particular installation requirements. [0128] Additionally, a further cover (not shown) could be applied at local positions along the length, or along the full length of the fibre linear tensile element, and could comprise a steel mesh co-extruded in a polymer and/or additional fireproofing materials. [0129] Running along the central axis of the fibre linear tensile element 2 is an optical fibre 23 which performs a monitoring function, as will be described later. The upper end termination 52 comprises a clamp portion 521 which receives and is securely clamped onto the upper end of the fibre linear tensile element 2 . Above this is a threaded portion 522 . Similarly, the lower end termination 62 comprises a clamp portion 621 and a threaded portion 622 . [0130] Within the clamp portion 521 , the upper end of the fibre linear tensile element 2 spreads apart, enabling the optical fibre 23 to be led out the side of the clamp portion 521 . Similarly, at the bottom end, the optical fibre 23 is freed from within the cylindrical core 21 and sheath 22 and is led out through the side of the lower clamp portion 621 . Thus the optical fibre 23 may be connected into a monitoring circuit, as will be described later. [0131] Considering FIGS. 4 and 5 , the thread of the upper adjustment nut 53 cooperates with the threaded portion 522 to permit longitudinal adjustment of the position of the clamp portion 521 relative to the anchor bracket 51 . At the other end of the fibre linear tensile element 2 , the adjustment nut 63 may be rotated on the threaded portion 622 in order to adjust up and down the position of the clamp portion 621 relative to the anchor bracket 61 . One or both of the adjustment nuts 53 , 63 may be operated to increase or reduce the tension of the fibre linear tensile element 2 . By careful synchronised adjustment of the two nuts 53 , 63 , it is also possible to maintain the existing tension of the fibre linear tensile element 2 whilst adjusting up or down the position of the fibre linear tensile element 2 and the clamping devices 3 that it carries. [0132] A representative clamping device 3 will now be described with reference to FIGS. 6-10 . At the rear of the clamping device is a two-part duct 31 comprising a channel portion 311 and a removable cover plate 312 . The fibre linear tensile element 2 passes through the bore of the duct 31 and is securely gripped by clamping structure 313 inside the duct. Four releasable fasteners 314 secure the cover plate 312 to the channel portion 311 , and produce a size and configuration of the bore through the duct such that the clamping structure 313 securely clamps the clamping device 3 onto the fibre linear tensile element 2 . [0133] In front of the duct 31 is a clamping arrangement for clamping the corners of four panels 4 . This clamping arrangement comprises a back plate 32 , a bracket 33 , a front plate 34 and two gaskets 35 which are interposed between the front and back plates 32 , 34 . [0134] The back plate 32 and bracket 33 are most clearly shown in FIGS. 9 and 10 . [0135] All of the structural components of the clamping device 3 are fabricated from metal, and the back plate 32 is molded to be integral with the channel portion 311 . The bracket 33 is molded integrally with the back plate 32 and projects forwards from the front face thereof. The bracket 33 comprises a horizontal flange 331 at the middle of which are an upper divider 332 and a lower divider 333 . The top face of the flange 331 is split into left and right seat portions 334 , 335 by the upwardly-projecting divider 332 . The bottom face of the flange 331 is split into left and right guide portions 336 , 337 by the downwardly-projecting divider 333 . [0136] The left seat portion 334 with the upper divider 332 and the back plate 32 define a recess or socket for receiving a corner of a panel 4 . Similarly, the right seat portion 335 with the upper divider 332 and the front face of the back plate 32 define another recess or socket. [0137] Again, each one of the left and right guide portions 336 , 337 with the lower divider 333 and the back plate 32 define a respective recess or socket. [0138] In use, the clamping device 3 is positioned at a connection node of the panel skin of the curtain wall, and the four recesses or sockets receive respective corners of the four panels at the connection node. The two upper panels will sit on the left and right seat portions 334 , 335 . The tops of the two lower panels will touch or be positioned close to the left and right guide portions 336 , 337 . [0139] The thickness (vertical height) of the flange 331 defines the size of the inter-panel gap between the two upper panels and the two lower panels. [0140] The common thickness (horizontal width) of the upper and lower dividers 332 , 333 defines the size of the inter-panel gap between the two left panels and the two right panels. [0141] The front plate 34 is releasably fastened onto the front face of the bracket 33 by two fasteners 36 each of which extends through a smooth aperture 321 in the back plate 32 and then through smooth apertures 351 in the two gaskets 35 before threadedly engaging with a threaded aperture 341 in the rear face of the front plate 34 . [0142] The correct positioning of the front plate 34 is ensured by two studs 342 which project into respective sockets 338 in the front face of the flange 331 . [0143] When the panels 4 are being installed, the front plate 34 and the frontmost one of the two gaskets 35 are initially left off. Of the four panels at the connection node defined by the clamping device 3 , the top right-hand corner of the lower left panel is located by the left guide portion 336 and the lower divider 333 . The top left-hand corner of the lower right panel is located by the right guide portion 337 and the lower divider 333 . The two lower panels are then temporarily held in position by locking arms (not shown) which are fitted into apertures 315 aligned along the vertical inter-panel joint. [0144] The two upper panels of the group of four panels 4 are then fitted. The bottom right-hand corner of the upper left panel is located against the left seat portion 334 and the upper divider 332 . The bottom left-hand corner of the upper right panel is located against the right seat portion 335 and the upper divider 332 . The two upper panels may then be temporarily held in position by further locking arms (not shown) inserted into respective ones of apertures 316 in the upper part of the front face of the duct 31 . [0145] The frontmost one of the two gaskets 35 is then positioned on the bracket 33 against the front faces of the four panels 4 . The front plate 34 is then fitted onto the bracket 33 , with the studs 342 locating in the sockets 338 . The two fasteners 36 are then inserted through the apertures 321 , 351 and engage with the threaded apertures 341 in the rear of the front plate 34 in order to clamp the front plate 34 in position, and thereby resiliently clamp the four panels 4 between the gaskets 35 . The temporary locking arms may then be removed from the apertures 315 , 316 and sealant applied to the inter-panel joints. The end result is as shown in FIG. 6 . [0146] As shown in FIG. 10 , the length Y 1 of the duct 31 is at least three times the height Y 2 of the back plate 32 in order to reduce unwanted twisting of the clamping device 3 on the fibre linear tensile element 2 about the axis perpendicular to the plane of the paper of FIG. 10 . [0147] Also, the width X 1 of the back plate 32 is about 80% of the length Y 1 of the duct 31 . As may be seen in FIG. 10 , this gives the clamping device 3 a cross-like appearance. [0148] The front plate 34 and the two gaskets 35 are substantially the same shape and size as the back plate 32 . The generally cross-like appearance as shown in FIG. 10 means that the major components of the clamping device 3 are aligned either generally along a vertical inter-panel joint (in the case of the duct 31 ) or generally along a horizontal inter-panel joint (in the case of the back plate 32 , front plate 34 and gaskets 35 ). This helps to make the clamping device less visually intrusive. [0149] The front plate 34 and the back plate 32 are each wider than the bracket 33 . Consequently the two apertures 321 in the back plate 32 are positioned laterally outwardly of the left and right ends of the flange 331 of the bracket 33 , rather than in the flange 331 itself. Consequently, the thickness of the flange 331 is substantially the same as the diameter of the shanks of the fasteners 36 . This enables the thickness of the horizontal inter-panel joint to be kept fairly small (and thus visually attractive) compared with the thicker joint that would be needed if the apertures 321 were to be provided in the flange 331 . As it is the bracket 33 that projects through the panel skin, it is the dimensions of the bracket which determine the thicknesses of the vertical and horizontal inter-panel joints. Generally speaking, these thicknesses should be kept fairly small, as long as the bracket 33 is not made so thin as to become structurally too weak. [0150] FIGS. 11 and 12 show a second embodiment of the present invention. Similar reference numerals are used in the second embodiment as for the first embodiment, in order to avoid repetition. [0151] The second embodiment differs from the first embodiment mainly in that the curtain wall 80 is curved, in that it is sinuous along its length. [0152] The individual square panels 4 are still planar because the curvature along the curtain wall 80 is gentle enough to permit planar panels to be used. [0153] As shown in FIG. 11 , the second embodiment includes a monitoring device 81 connected to form monitoring circuits with the optical fibres 23 of the fibre linear tensile elements 2 . The optical fibres 23 are connected in parallel, so that any fall-off in tension of a particular fibre linear tensile element 2 may be detected and that particular fibre linear tensile element 2 identified. [0154] With regard to the third embodiment shown in FIG. 13 , there are two curtain walls each using the panel system of the present invention. There is the outer curtain wall 80 and an inner curtain wall 82 . Each wall uses glass panels 4 , so it is possible to see through both of the walls. Struts 83 extend between the two walls 80 , 82 in order to maintain the spacing between the two walls. The struts could also support a walkway positioned in the gap between the two walls, or components (such as lighting, blinds etc.) could be attached to the struts 83 in order to be positioned in the gap between the walls. [0155] There is an air entrance (not shown) leading into the gap and an air exit (not shown) for ducting air out of the gap, so that overall the gap between the two walls 80 , 82 can function as a flue. This may be useful when, for example, the two walls 80 , 82 are south-facing because the flue will help to maintain a cool climate within the building in the summer. In other words, the two walls act as a thermal buffer between the external environment and the interior 84 of the building. The gap between the two walls functions as a convection-ventilated flue. [0156] Perhaps if the struts 83 are not present, or else are capable of permitting some variation in their length, flexing of the outer wall 80 relative to the inner wall 82 could be used to some extent at least to “pump” the air through the flue. It may usually be necessary to supplement this pumping with a conventional fan that can be controlled by the building's control system. [0157] For a pair of walls extending along the long facade of a building, there will usually be a plurality of air entrances into the flue and a plurality of air exits, spaced at positions along the building facade. [0158] With regard to the fourth embodiment shown in FIG. 14 , this illustrates how the optical fibre monitoring device 81 may output the information regarding the state of the tensioning of the fibre linear tensile elements 2 . It could output information, such as an alarm signal indicating that a particular fibre linear tensile element 2 has an unacceptably-low tension, directly to a computer 85 over a wireless link 86 . The computer 85 could be elsewhere in the building or elsewhere on the site, and might be part of the overall building control system for managing the functioning of the building (e.g. heating and lighting). [0159] Alternatively or additionally, the information output from the monitoring device 81 could be transmitted over the internet 87 to a computer 88 which could be anywhere in the world. [0160] We expect that most commercial embodiments of the present invention will involve the panel system providing a panel skin which is a wall, as shown in the embodiments of FIGS. 1 to 14 . Alternatively, the panel skin could be provided as the roof of a building as shown in FIG. 15 . For the fifth embodiment of FIG. 15 , the same reference numerals are used as for the analogous components of the preceding embodiments. The main difference is that the fibre linear tensile elements 2 extend between a pair of generally parallel roof beams 15 , 16 . Instead of glazing profiles 75 , 76 being used (as in the earlier curtain wall embodiments), the roof 89 formed by the panel skin has its longitudinal edges supported on and sealed by longitudinal strips 17 , 18 which space the roof 89 slightly above the top surfaces of the roof beams 15 , 16 . The arrangement of fibre linear tensile elements 2 and the longitudinal strips 17 , 18 may be such as to impart a slight slope to the roof 89 , e.g. for water drainage. [0161] It will be appreciated that the above description is non-limiting and refers to the currently-preferred embodiments of the invention. Many modifications may be made within the scope of the invention. Although features believed to be of particular significance are identified in the appended claims, the applicant claims protection for any novel feature or idea described herein and/or illustrated in the drawings, whether or not emphasis has been placed thereon.

Fibre linear tensile elements 2 are strung between the floor slab 11 and the roof 12 of a building 1. Each fibre linear tensile element has a structural core 21 of polymeric fibres or filaments which can accommodate the tensioning of the fibre linear tensile element. The core 21 is covered by a sheath 22 of polymeric material. The fibre linear tensile elements 2 carry clamping devices 3 which enable glass panels 4 to be secured in position. Each clamping device 3 clamps in position the corners of four adjacent panels 4 at a particular connection node of the glass wall 80, as shown in FIG. 6. Gaskets 78 are applied to fill the inter-panel joints. Each fibre linear tensile element 2 may include a central optical fibre 23 for detecting any reduction in the tension during use. The tension of the fibre linear tensile elements 2 is monitored by a monitoring device 81 which can produce an appropriate alarm signal. Because of the polymeric structural nature of the fibre linear tensile elements 2, they will permit the curtain wall 80 to flex to some extent and their tensioning will only vary slightly in response to changes in ambient temperature. The polymeric material is also good at resisting surface corrosion. The fibre linear tensile elements 2 with the clamping devices 3 prefitted are delivered to site on pallets 71, so as to reduce the amount of work required on site. A laser level 74 may be used to ensure that the clamping devices 3 are positioned at their correct heights, before the glass panels 4 are fitted.

BACKGROUND OF THE INVENTION The invention relates to a method for delignification of chemical wood pulp by oxygen-alkali treatment. Delignification with oxygen and alkali is today an industrially accepted process. The process is usually conducted as a pre-bleaching step before the final bleaching with chlorine containing chemicals. The kappa number of the pulp is then reduced usually from about 35 to 30 to a value of 20 to 15, implying a degree of delignification of about 40 to 50%. The values refer to oxygen-alkali delignification of sulphate pulps of coniferous woods. It is also known that sulphate pulp having a kappa number within the range of 50 to 70 can be pre-bleached with oxygen and alkali. The reduction of the kappa number in such an oxygen-alkali delignification stage is usually restricted to 25 to 30 kappa number units. Delignification with oxygen and alkali can be carried out both at high pulp consistency (25 to 30%) and at medium pulp consistency (7 to 10%). In the oxygen-alkali treatment of sulphate pulps having a kappa number in the range of 50 to 70 the process is usually carried out at medium pulp consistency. In the oxygen-alkali treatment of sulphate pulps having a kappa number in the range of 30 to 35 a high pulp consistency is mainly used. In processes based on medium pulp consistency hydraulic reactors are used, i.e. liquid filled reactors having no gas phase in the reactor. The oxygen gas must be dispersed as small gas bubbles in the liquid phase surrounding the fibres. This means that there exists an upper limit for the amount of oxygen gas that can be charged to the reactor together with the pulp. This upper limit is defined by the pulp consistency, the reactor pressure and the reactor temperature. At a reactor pressure of 0,6 MPa, a pulp consistency of 8 to 10% and a reactor temperature of 95 to 110° C. the oxygen charge is restricted to ˜40 kg O 2 per ton of 100% unbleached pulp. The kappa number reduction in such a stage using a medium pulp consistency is restricted to about 30 kappa number units. In a reactor system based on high pulp consistency there is always a gas phase of oxygen present in the reactor. The charge of alkali governs the kappa number reduction. The strength characteristics of the pulp usually represent a limit for the kappa number reduction or the degree of delignification. A high alkali charge leads to a high alkali concentration. Furthermore, there is a relation between the carbohydrate decomposition and the alkali concentration. At high alkali concentrations the carbohydrate decomposition measured as the intrinsic viscosity of the pulp or yield loss is strongly increased. In order to reduce the decomposition of the carbohydrates magnesium salts are usually added. Another method known from the literature is to treat the sulphate pulp with an acid solution having a pH value of <4 prior to the oxygen-alkali delignification stage. In this manner heavy metal iones are removed from the pulp, whereby the decomposition of carbohydrates is reduced. It is still necessary to limit the alkali charge to about 25 to 35 kg NaOH per ton of 100% unbleached pulp in order to limit the carbohydrate decomposition to an acceptable level. This limits the kappa number reduction to about 20 units. SUMMARY OF THE INVENTION The object of the present invention is to provide an industrially acceptable delignification process allowing an increase of the kappa number reduction in an oxygen-alkali delignification stage without increasing the charge of oxygen and alkali. It has been found that this may be done by modifying the residual lignin in the unbleached sulphate pulp. Specifically, the modification involves introducing hydrophilic groups in the sulphate lignin to make it more easily dissolved in the subsequent oxygen-alkali delignification stage. The introductioh of hydrophilic groups may preferably be effected by sulphonating sulphate or polysulphide pulps with a solution of sodium sulphite or sodium bisulphite prior to the oxygen-alkali delignification. It has further been found that absorption liquor from industrial stack gas scrubbers is well suited as a pretreatment solution prior to the oxygen-alkali delignification. This makes the pretreatment practically costless. Other sources of SO 2 can also be used for pretreatment of the pulp. DETAILED DESCRIPTION OF THE INVENTION The invention is illustrated in more detail by the subsequent examples. The first six examples describe laboratory experiments with a sulphite treatment followed by an oxygen-alkali delignification. The next six examples relate to experiments in production plant scale. CONTROL EXAMPLE A The treated pulp was an industrially produced polysulphide pulp of spruce and pine. The kappa number was measured as 62.2. This pulp was delignified in the laboratory with oxygen and alkali. O 2 pressure 0.8 MPa (20° C.), temperature 110° C., 10% pulp consistency and 45 min reaction time. The alkali charge was 25 kg NaOH per ton of 100% pulp. To stabilize the pulp against carbohydrate decomposition 1 kg Mg ++ per ton of 100% pulp was added. After oxygen-alkali delignification the pulp was washed and the kappa number was determined. EXAMPLE 1 The same pulp as in control example A was treated with a sodium sulphite solution at a pH value of 8.0, a temperature of 88° C., a pulp consistency of 10% and a treatment time of 60 min. The sulphite charge was 10 kg calculated as SO 2 per ton of 100% pulp. After the sulphite pretreatment the pulp was washed. This pulp was further delignified with oxygen and alkali in the laboratory. O 2 pressure 0.8 MPa (20° C.), 110° C., 10% pulp consistency and 45 min reaction time. The alkali charge was 25 kg NaOH per ton of 100% pulp. 1 kg Mg ++ per ton of 100% pulp was added as an inhibitor. After oxygen-alkali delignification the pulp was washed and the kappa number was determined. EXAMPLE 2 The same pulp as in control example A was treated with a sodium sulphite solution at a pH value of 8.0, a temperature of 88° C., a pulp consistency of 10% and a treatment time of 60 min. The sulphite charge was 30 kg calculated as SO 2 per ton of 100% pulp. After the sulphite pretreatment the pulp was washed. This pulp was further delignified with oxygen and alkali in the laboratory. The same conditions as described in example 1 were used. CONTROL EXAMPLE B The treated pulp was a laboratory produced sulphate pulp of spruce having a kappa number of 98.3. This pulp was further delignified with oxygen and alkali in the laboratory. O 2 pressure 0.8 MPa (20° C.), 110° C., 10% pulp consistency and 75 min reaction time. The alkali charge was 40 kg NaOH per ton of 100% pulp. 1 kg Mg ++ per ton of 100% pulp was added as an inhibitor. After oxygen-alkali delignification the pulp was washed and the kappa number was determined. EXAMPLE 3 The same pulp as in control example B was treated with a sodium sulphite solution at a pH value of 8.0, a temperature of 88° C., a pulp consistency of 10% and a treatment time of 60 min. The sulphite charge was 10 kg calculated as SO 2 per ton of 100% pulp. After the sulfite pretreatment the pulp was washed. This pulp was further delignified with oxygen and alkali in the laboratory. The same conditions as described in control example B were used. EXAMPLE 4 The same pulp as in control example B was treated with a sodium sulphite solution at a pH value of 8.0, a temperature of 88° C., a pulp consistency of 10% and a treatment time of 60 min. The sulphite charge was 30 kg calculated as SO 2 per ton of 100% pulp. After the sulphite pretreatment the pulp was further delignified with oxygen and alkali in the laboratory under the same conditions as in control example B. The examples 5 to 7 and the control examples C to E relate to experiments in production plant scale. The pulps had been produced by polysulphide digesting in a continuous Kamyr digester having a "Hi-Heat" washing zone in the lower part of the digester. The wash water is added at the bottom of the digester and washes the pulp in counter current. A part of the pulp is blown through an in-line splitter to an oxygen-alkali delignification plant of the type Kamyr MC (medium consistency). This plant consists of a receiver standpipe, an MC pump, a pressure diffuser washer, an in-line disc refiner, an MC mixer, a hydraulic reactor, a small flash cyclone and a wash press. The wash liquor from the wash press is used as wash water in the pressure diffuser. The kappa numbers refer to average values over one day. CONTROL EXAMPLE C The treated pulp was an industrial polysulphide pulp which was further delignified with oxygen and alkali after an intermediate wash in a continuous pressure diffuser. The charges of oxygen and alkali were 29 kg O 2 and 34 kg NaOH, respectively, per ton of 100% pulp. Other conditions in the oxygen-alkali stage were: temperature 103° C., pulp consistency about 9% and reactor pressure 0.6 MPa (absolute). The retention time in the reactor was 35 min. After the oxygen-alkali delignification the pulp was washed and the kappa number was determined. EXAMPLE 5 The treated pulp was an industrial polysulphide pulp which was treated with a sulphite solution prior to further delignification with oxygen and alkali. The sulphite solution was added to the wash water passed to the bottom of the digester in an amount corresponding to 25 to 30 kg SO 2 per ton of 100% pulp. The conditions were: temperature about 85° C., pulp consistency about 9% and treatment time about 5 min. After the sulphite pretreatment the pulp was washed in a continuous pressure diffuser prior to addition of oxygen and alkali in amounts of 29 kg O 2 and 34 kg NaOH, respectively, for each ton of 100% pulp. Other conditions were: temperature 103° C., pulp consistency 9% and reactor pressure 0.6 MPa (absolute). The retention time in the reactor was 35 min. After the oxygen-alkali treatment the pulp was washed and the kappa number was determined. CONTROL EXAMPLE D The same treatment procedure as in control example C was used. The charges of oxygen and alkali were in this case 35 kg O 2 and 41 kg NaOH, respectively, per ton of 100% pulp. The reaction conditions in the oxygen-alkali stage were the same as described in example 5. After the oxygen-alkali stage the pulp was washed and the kappa number was determined. EXAMPLE 6 The pulp was an industrial polysulphide pulp which was treated with a sulphite solution prior to further delignification with oxygen and alkali. The sulphite pretreatment was the same as described in example 5. After the sulphite pretreatment the pulp was washed in a continuous pressure diffuser prior to addition of oxygen and alkali in amounts of 35 kg O 2 and 42 kg NaOH, respectively, per ton of 100% pulp. The conditions in the oxygen stage were the same as described in example 5. After the oxygen-alkali stage the pulp was washed and the kappa number was determined. CONTROL EXAMPLE E The same procedure as in control example C was used. The charges of oxygen and alkali were in this case 35 kg O 2 and 45 kg NaOH, respectively, per ton of 100% pulp. In this example oxidized white liquor was used as an alkali source. The reaction conditions in the oxygen stage were the same as in example 5. After the oxygen-alkali stage the pulp was washed and the kappa number was determined. EXAMPLE 7 The pulp was an industrial polysulphide pulp which was treated with a sulphite solution in the lower part of the Kamyr digester as described in example 5. Subsequent to the sulphite pretreatment the pulp was washed in a continuous pressure diffuser prior to the addition of oxygen and alkali in amounts of 39 kg O 2 and 44 kg NaOH, respectively, per ton of 100% pulp. Oxidized white liquor was used as an alkali source. The reaction conditions in the oxygen-alkali stage were otherwise the same as described in example 5. After the oxygen-alkali delignification the pulp was washed and the kappa number was determined. The kappa numbers are given in the Table. As seen from the examples an increased kappa number reduction is obtained in the oxygen-alkali pretreatment when the pulps are pretreated with a sulphite solution. At a given kappa number of the unbleached pulp considerably lower kappa numbers can be obtained after an oxygen-alkali delignification if the pulp has been pretreated with a sulphite solution. When the pulp is bleached with chlorine containing chemicals the increased kappa number reduction in the oxygen-alkali stage means that the consumption of bleaching chemicals can be substantially reduced. Additionally, the effluent of chlorine containing waste liquors is reduced. Thus, the sulphite pretreatment leads to an environmental advantage. If the kappa number after the oxygen-alkali stage is maintained constant, the pretreatment of the pulp with a sulphite solution prior to the oxygen-alkali delignification stage implies that the kappa number of the unbleached pulp can be increased. TABLE______________________________________Sulphitecharge,kg SO.sub.2 per Kappaton of un- Kappa number numberbleached pulp unbleached O.sub.2 bleached reduction______________________________________Control 0 62.2 42.2 20.0example AExample 1 10 62.2 37.4 24.8Example 2 30 62.2 34.9 27.3Control 0 98.3 50.5 47.8example BExample 3 10 98.3 47.4 50.9Example 4 30 98.3 45.6 52.7Control 0 55.9 29.2 26.7example CExample 5 25-30 58.2 25.7 32.5Control 0 61.3 32.4 28.9example DFxample 6 25-30 66.8 30.8 36.1Control 0 59.2 33.0 26.2example EExample 7 25-30 65.1 30.0 35.1______________________________________ This gives a higher pulp yield, thereby reducing the cost of wood for each ton of pulp. The effect of the invention has been demonstrated in connection with an oxygen-alkali delignification stage at medium pulp consistency, but those skilled in the art will expect that the same will also hold true in the case of oxygen-alkali delignification at higher pulp consistencies. In the examples ordinary sulphate and polysulphide pulps are used, but those skilled in the art will expect that corresponding results will also be obtained with sulphate and polysulphide pulps digested with an addition of anthraquinone to the cooking liquor and with soda pulps with or without addition of anthraquinone. The effect will also be present in the casing of treating the pulp with a sulphite or bisulphite solution between two oxygen-alkali delignification stage. Especially, the invention may be utilized in the oxygen-alkali delignification of pulps having higher kappa numbers than 30 to 35.

In the delignification of chemical wood pulp with oxygen and alkali a larger reduction of the kappa number may be obtained without an increase in the charge of oxygen or alkali, provided the pulp is pretreated with a solution of sulphite or bisulphite in order to introduce hydrophilic groups in the sulphate lignin in the chemical wood pulp.

FIELD OF THE INVENTION The invention relates to methods and compositions useful for improved recovery of coated paperboard composites. BACKGROUND In today's environmentally conscious society, the environmental impact of disposal containers is of great concern. One area of concern that remains to be adequately addressed is the recyclability of paperboard packages coated with polymeric materials such as polyethylene. While such coated paperboard packages are generally recyclable, a small but significant portion of the composite paperboard packages now commercially available cannot be efficiently or economically recycled with current technology. The inability to recycle 100 percent of the polymeric material and paperboard substrate of the coated paperboard packages is due, at least in part, to the low-value of fiber-contaminated polymer that must be disposed of by means other than recycling. Various techniques for the partial recycling of coated paperboard composites are commercially available. One common technique is the repulping of the coated paperboard whereby polymeric coating material is separated from the paperboard substrate by floatation. Another technique is the use of organic solvents to dissolve the polymeric coating and thereby separate the polymeric coating from the substrate. While these techniques are relatively simple, at best only about 98 wt. % of the paperboard fiber is recoverable and typically only 50 wt. % to 75 wt. % of the paperboard fiber is recoverable. Furthermore, the polymeric material which may contain as little as 2 wt. % fiber has little or no value due to its fiber content. If solvents are used to dissolve the polymeric material, expensive distillation, extraction or other separation techniques are required to recover the polymeric material from the solvent. Consequently, the polymeric material separated from the paperboard substrate is generally landfilled or incinerated. If, on the other hand, essentially all of the paperboard substrate and polymeric coating material is recoverable, there would be an economic incentive to recycle more of the polymeric material coated paperboard containers. Currently, the economics of recycling such coated paperboard containers are adversely impacted by the cost for landfill and/or incineration of the low-value, fiber or solvent contaminated polymeric material. It is therefore an object of the invention to provide compositions and methods which enhance the recoverability of polymeric material coated paperboard composites. Another object of the invention is to provide a method for recycling and recovering polymeric coatings and paperboard substrates from polymer coated paperboard composites using commercially available repulping techniques. Yet another object of the invention is to provide a method for increasing the rate of recovery of polymeric coating material and paperboard substrate in a commercially acceptable manner. Other objects and benefits of the invention will be evident from the ensuing description and appended claims. SUMMARY OF THE INVENTION With regard to the foregoing and other objects, the present invention provides a polymer coated multilaminar paperboard composite comprising a paperboard substrate having two surfaces, a highly alcoholized polyvinyl alcohol binder layer adjacent to at least one surface of the paperboard substrate and a polyethylene layer bound to the polyvinyl alcohol layer, wherein the highly alcoholized polyvinyl alcohol layer is present in an amount of from about 2 to about 12 pounds per 3000 square feet (about 0.9 to about 5.4 kg/280 m 2 ) of substrate. The products of the invention greatly enhance the recyclability of coated paper and paperboard composites. Accordingly, up to about 95 wt. % or more of the polymeric coating and substrate may be recovered and recycled using the products and methods of the invention without the need for solvents and/or complicated coating removal techniques. In another embodiment, the invention provides a method for making recyclable coated paperboard composites. The recyclable composites are made from a cellulosic paperboard substrate having two surfaces by coating at least one surface of the substrate with a highly alcoholized polyvinyl alcohol binder. A polyethylene coating layer is then applied to the polyvinyl alcohol binder to provide a paperboard composite. The amount of polyvinyl alcohol coating applied to the substrate is in a range of from about 2 to about 12 pounds per 3000 square feet (about 0.9 to about 5.4 kg/280 m 2 ) of substrate. The adherence of a coating to a paper or paperboard substrate is due, at least in part, to the penetration of substrate fibers into the coating layer. From an adherence point of view it is desirable to have as many fibers penetrate and anchor themselves in the coating layer as possible. However, complete separation of the substrate from the coating becomes increasingly more difficult as the number of fibers anchored in the coating layer increases. By using a highly alcoholized polyvinyl alcohol as a binder layer between the polymeric coating and substrate, fewer substrate fibers are allowed to penetrate and anchor themselves in the polymeric coating. The substrate fibers are anchored in the polyvinyl alcohol layer which serves as a bridge to adherently bind the polymer coating to the substrate. Since the bulk of the substrate fibers do not extend past the binder layer into the coating layer, there is more complete separation between the substrate and the polymeric coating layer. A further embodiment of the invention provides a method for recovering paperboard fibers and a polymeric coating material from a coated paperboard substrate. The method comprises first chopping or otherwise mechanically subdividing or disintegrating a fibrous paperboard substrate coated with a polyethylene layer and a highly alcoholized polyvinyl alcohol binder interposed between the substrate and polyethylene layer. Next the chopped substrate is fed to a repulper such as a Hydrapulper containing hot water and, preferably, alkali, for dissolution of the polyvinyl alcohol binder and disintegration of the substrate into individual fibers and small fiber bundles. Finally the polyethylene coating, now also disintegrated into small particles in an aqueous slurry containing paperboard fibers, polyethylene particles and dissolved polyvinyl alcohol are separated one from the other as by floatation separation, screening or centrifuging thereby recovering substantially polyethylene free paperboard fibers and substantially fiber and polyvinyl alcohol free polyethylene. A still further embodiment of the invention provides a method for recovering paperboard fibers and a polymeric coating material. The method comprises first chopping or otherwise mechanically subdividing or disintegrating a multilaminar fibrous paperboard substrate coated with polyethylene and a highly alcoholized polyvinyl alcohol binder layer interposed between the substrate and the polyethylene layer. The highly alcoholized polyvinyl alcohol is present in the coating an amount ranging from about 2 to about 12 pounds per 3000 square feet of substrate and the polyvinyl alcohol has a degree of hydrolysis of greater than about 99%. Next the chopped substrate is fed to a vessel containing water. A partial vacuum is momentarily applied to the headspace of the vessel containing the chopped substrate. The partial vacuum is applied and released for a number of cycles (typically 3) sufficient to effectively wet the fibrous substrate. The water containing the chopped and wet substrate is then heated to a temperature sufficient to dissolve the highly alcoholized polyvinyl alcohol layer. Next the chopped substrate is soaked for a period of time at the dissolving temperature which time and temperature are sufficient to dissolve the highly alcoholized polyvinyl alcohol layer thereby effectively separating substrate fibers and polyethylene particles one from the other and disintegrating the substrate into individual fibers and small fiber bundles. Once the paperboard fibers, polyethylene particles and dissolved polyvinyl alcohol are separated one from the other, an aqueous slurry containing the paperboard fibers, the polyethylene particles and dissolved polyvinyl alcohol may be recovered as by floatation separation, screening or centrifuging in order to obtain substantially polyethylene free paperboard fibers and substantially fiber and polyvinyl alcohol free polyethylene. DETAILED DESCRIPTION OF THE INVENTION The invention is directed to the production, use and recycling of paperboard composites containing one or more polymeric layers or coatings, particularly a polyethylene barrier layer, and especially a low density polyethylene barrier layer applied to a paper or paperboard substrate such as multiply bleached kraft carton material for packaging various consumer products, for example, dairy products and juices and any other polyethylene-coated paper and board products. The invention involves the use of a water dissolvable or dispersible material interposed between the polymer layer and the substrate to bind the two together. A preferred binder is substantially insoluble in water below about 170° F. (77° C.), but becomes soluble or dispersible in water having a temperature above about 170° F. (77° C.). The solubility of the binder for use in the composite of the invention may be determined by how readily the substrate and coating separate from one another in hot water. Generally speaking, the more readily the coating releases from the substrate, the more suitable is the binder for use in the invention. The invention employs as a binder for the polymeric coating a highly alcoholized polyvinyl alcohol (PVA) as distinguished from conventional alcoholized polyvinyl alcohols. Highly alcoholized means that the degree of hydrolysis of the PVA is greater than about 98%, most preferably greater than about 99%. For food container applications, the PVA is a food and drug grade material. A particularly preferred highly alcoholized PVA is the PVA having a degree of hydrolysis of 99.3% or more available from Air Products, Inc. located in Allentown, Pa., under the trade designation AIRVOL 165. Highly alcoholized PVA binders for use in the invention may be produced from polyvinyl esters such as polyvinyl acetate since the vinyl alcohol monomer itself is unstable and will readily rearrange to acetaldehyde. Vinyl acetate, which is polymerized to polyvinyl acetate, may be made by the addition of acetic acid to acetylene in the presence of mercuric sulfate. Methods for the production of polyvinyl acetate are well known in the art. Polyvinyl acetate may then be converted to polyvinyl alcohol by the acid catalyzed hydrolysis of polyvinyl acetate. Suitable catalysts include p-toluenesulfonic acid, benzenesulfonic acid, phenolsulfonic acid, xylenesulfonic acid, hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. A preferred reaction for production of PVA for the invention is the hydrolysis of polyvinyl acetate by methanol in an acid or base catalyzed reaction. In this case, polyvinyl alcohol and methyl acetate are formed. Methyl acetate, having a lower boiling point than polyvinyl alcohol, may be readily removed from the reaction product mixture by distillation. The degree of alcoholysis obtained is determined by the number of acetate groups which have been hydrolyzed. Methods for increasing the degree of alcoholysis are well known in the art. See for example, U.S. Pat. No. 3,497,487 to Bristol; U.S. Pat. No. 3,541,069 to Bristol, et al.; and U.S. Pat. No. 3,654,247 to Bristol, all of which are incorporated herein by reference as if fully set forth. Such highly alcoholized polyvinyl alcohols are typically insoluble in cold water, i.e., have a cold water solubles content of less than 10% by weight at 77° F. (25° C.) and are highly soluble in hot water, i.e., have a water solubles content of greater than 50% by weight at a temperature of 176° F. (80° C.)or higher. Besides having a degree of hydrolysis of greater than 99%, the PVA binder preferably has a viscosity of greater than about 40 to about 75 centipoise in a 4% aqueous solution at 20° C., more preferably greater than about 55 centipoise, and most preferably from about 60 to about 75 centipoise. Typically the binder will also have a number average molecular weight of from about 5,000 to about 110,000, with higher molecular weights being preferred. The substrate coated with the highly alcoholized binder and polymeric coating of this invention is a cellulosic fibrous material which is to be recycled. The substrate may therefore be composed of a single cellulosic layer of fibrous material or the substrate may contain a plurality of cellulosic layers. Such multilayer cellulosic substrates are used in producing liquid containers, cartons and the like for milk, juices and other liquids. Until now, however, these cartons and containers have not been fully recyclable due to the inability to completely separate the cellulosic fibers and coating material from one another. Once formed, the single or multilaminar cellulosic substrate may be coated on one or both surfaces depending on the particular application for which the coated substrate is used. Regardless of whether one or both surfaces of the substrate are coated, this invention provides compositions and methods for enhancing the recyclability of such coated substrate composite materials. To produce the coated substrate of the invention, the fibrous substrate is first coated with a binder, preferably the highly alcoholized PVA herein described so that the total binder coating ranges from about 2 to about 12 pounds per 3000 square feet (about 0.9 to about 5.4 kg/280 m 2 ) of substrate. The substrate may be coated with the binder by first dissolving about 10 parts of the binder in about 90 parts of water at a temperature above about 80° C. The resultant solution may then be applied to the cellulosic substrate by conventional methods such as spraying, roll coating, doctor blade, brushing or any other suitable coating technique. If desired, the binder may also be extruded onto the substrate from a melt of the binder without first dissolving the binder in water. Once coated with the binder, the binder coated substrate may then treated by flame or corona discharge techniques to enhance the binding characteristics of the binder with the polymeric layer. These treating techniques are well known in the art. In the alternative, a tie layer may be applied to the binder or an amphiphilic additive such as that disclosed in U.S. Pat. No. 5,190,816 to Gardiner et al., which is incorporated herein by reference as if fully set forth, may be added to the polymeric material to enhance the adherence between the binder and the polymeric layer. A preferred polymeric layer generally includes one or more tie layers of ethylene-based copolymers modified with functional groups such as PLEXAR 175 or PLEXAR 177, available from Quantum Chemical Corporation located in Cincinnati, Ohio, used in combination with a low density polyethylene (LDPE) layer, an ethylene vinyl alcohol copolymer (EVOH) layer, a combination of layers of LDPE and EVOH, or any other desired polymeric material layers suitable for making coated paperboard composites. Particularly preferred ethylene vinyl alcohol copolymers are available from the Eval Company of America located in Lisle, Ill., and are sold under the trade name EVAL EP. Low density polyethylene may also be used alone as the tie layer. If the paperboard composites are used for food packaging, the polymeric layers should also be FDA approved for direct food contact. Like the binder layer, the polymeric layer may also be applied to the substrate containing the binder layer by spraying, roll coating, doctor blade, brushing or any other suitable coating technique. Typically, the polymeric layer is extrusion coated from a melt directly to the binder layer. This invention is not limited to the use of one such polymeric layer, as a plurality of polymeric layers may also be used. The total amount of polymeric layer used in making the paperboard substrate will usually be in the range of from about 10 pounds per 3000 square feet (4.5 kg/280 m 2 ) to about 40 pounds per 3000 square feet (18 kg/280 m 2 ). If both sides of the substrate are to be coated, then prior to applying the polymeric layer, both sides of the substrate should be coated with the hot water soluble or dispersible binder layer in order to enhance the recyclability of the paperboard composite. To separate the polymeric layer and the fibrous substrate as in a recycling operation, the composite is preferably first chopped, shredded or otherwise subdivided into small pieces and the resulting material is soaked in a vessel containing hot water for a period of time sufficient to dissolve or disperse the binder layer, resulting in release of the polymeric layer from the fibrous substrate. Hot water may be added to the chopped composite which was previously charged to a vessel, or more preferably, the composite is added to a vessel containing hot water. Thus, to enhance the action of the hot water on the composite, it is preferably chopped, shredded, or torn so as increase the surface area for contact with the hot water to expose as much of the binder to water as is reasonably practical. If there are no or only a few discontinuities in the barrier layer as are created by chopping or tearing the substrate, it may be difficult or take more time for the water to act upon the binder. While there may be a practical limit to the size of the chopped or shredded composite pieces, generally the smaller the pieces, the more efficient will be the coating release process. In the alternative, the chopped composite containing the binder and polymeric coated may be fed directly to a HYDRAPULPER repulper for treatment using well known repulper techniques in which the composite is disintegrated by the rotor and mechanical agitation in the process. It is important that the water used for removing the barrier films from paperboard substrates be hot enough to dissolve the binder layer in a reasonable amount of time. Accordingly, the water temperature for soaking the composite material should be above about 176° F. (80° C.), more preferably above about 185° F. (85° C.) and most preferably in the range of from about 194° F. (90° C.) to about 302° F. (150° C.). The water may be heated prior to introducing the substrate to the vessel, or it may be heated once the substrate is in the vessel. Either sequence may be used provided the water is heated and maintained at the desired temperature for a period of time sufficient to dissolve the hot water dissolvable layer. Agitation of the hot water containing the shredded paperboard composite material may be performed to increase the dissolution rate. However, the agitation rate is not believed to be critical to the invention. Once the polymeric coating has released from the substrate due to dissolution of the binder layer, the polymeric and fibrous material may be recovered by conventional methods known to those of ordinary skill such as floatation, skimming, screening or centrifuging the slurry. Although the invention has been described as removing the polymeric materials from the substrate, such terminology is not intended to convey a particular mechanism or sequence of events. Accordingly, the fibrous substrate and polymeric materials are separated one from the other by the methods of this invention. In another alternative procedure, the chopped composite is fed to a pressure vessel containing water at room temperature. A subatmospheric pressure is applied to the headspace of the vessel for a period of time sufficient to enhance wetting of the chopped material. A suitable subatmospheric pressure is in the range of from about 254 to about 650 mm Hg. Once the pressure in the vessel reaches the desired subatmospheric pressure, the vacuum is released. Subatmospheric pressure is applied to the vessel and released at least once, preferably twice, and more preferably at least three times so that the composite material is sufficiently wet. It is particularly preferred to use vacuum conditions to promote wetting of high wet strength paper and board products. Subsequent to the subatmospheric pressure wetting procedure, the water containing the chopped substrate is then heated to a temperature for a period of time sufficient to dissolve or disperse the binder layer. As noted above, the water temperature is preferably above about 176° F. (80° C.), more preferably above about 185° F. (85° C.) and most preferably in the range of from about 194° F. (90° C.) to about 302° F. (150° C.). As before, once the polymeric material has released from the vacuum wetted and heat soaked composite material by dissolution of the binder layer, the insoluble polymeric and fibrous material may be recovered by conventional methods. If recovery of the binder from the water is desired, such recovery may be obtained by cooling the water after fiber separation until the binder precipitates or by distillation or extraction techniques. The water containing the dissolved binder may also be used without first separating the binder from the fibrous substrate. In order to further illustrate the invention, the following non limiting examples are given. EXAMPLE 1 A 10% by weight solution of AIRVOL 165 super-hydrolyzed polyvinyl alcohol (PVA) from Air Products, Inc. was prepared by dispersing 10 parts of PVA in 90 parts distilled water and heating and agitating the mixture at 182° F. (82° C.) until the PVA was completely dissolved (about 30 minutes). Sheets of milk carton board were coated on one surface with low density polyethylene and the PVA solution was drawn down on the uncoated surface using a #8 Meyer rod. The coated sheets were dried in a laboratory oven at about 151° F. (66° C.) for 10 minutes. Two sets of coated sheets were made, one with a single drawdown of PVA and the other having a second drawdown of PVA over the first drawdown. The sheets were then taped to a web and PLEXAR 175 (a modified low density polyethylene tie resin from Quantum Chemical Corporation of Cincinnati, Ohio) at about 12 lbs/ream (5.44 kg/ream) was extruded on the PVA coated side of the sheets. The sheets of single drawdown and double drawdown samples with PLEXAR 175 overcoat were cut into 2.54 centimeter squares. Ten squares of each single and double drawdown sheets were placed in beakers of 199° F. (93° C.) water. The time of the first film release from a square was observed and recorded as well as the time required for all ten squares of each drawdown sample to release the PLEXAR films. Table 1 is a tabulation of the observed results. TABLE 1______________________________________ 1 Drawdown 2 Drawdowns of of PVA PVA______________________________________Release of 1st film 16 6(min.)Release of all films 24 22(min.)______________________________________ Approximately 100% of the original PLEXAR coating was recovered from the water. Upon microscopic examination, the recovered coating was determined to be essentially fiber-free. EXAMPLE 2 A 10% by weight solution of AIRVOL 165 super-hydrolyzed polyvinyl alcohol (PVA) from Air Products, Inc. was prepared by dispersing 10 parts of PVA in 90 parts distilled water and heating and agitating the mixture at 180° F. (82° C.) until the PVA was completely dissolved (about 30 minutes). Sheets of milk carton board were coated on one surface with polyethylene and the PVA solution was applied to the uncoated surface using a #8 Meyer rod. The coated sheets were dried in a laboratory oven at about 151° F. (66° C.) for 10 minutes. Two sets of coated sheets were made, one with a single drawdown of PVA and the other having a second drawdown of PVA over the first drawdown. The sheets were then taped to a web and PLEXAR 175 (a modified polyethylene tie resin of EVOH from Quantum Chemical Corporation) at about 12 lbs/ream (5.44 kg/ream) was extruded on the PVA coated side of the sheets. The sheets of single drawdown and double drawdown samples with PLEXAR 175 overcoat were cut into 2.54 centimeter squares. Ten squares of each single and double drawdown sheets were placed in beakers of 77° F. (25° C.) water. Subatmospheric pressure was applied to the beakers until the pressure reached 56 mm Hg. The vacuum was released and repeated several times while the squares were submerged in the water. When the squares appeared to be completely wet, the beakers containing the water and squares were heated to 199° F. (93° C.). The time of the first film release from a square was observed and recorded as well as the time required for all ten squares of each drawdown sample to release the PLEXAR films. Table 2 is a tabulation of the observed results. TABLE 2______________________________________ 1 Drawdown 2 Drawdowns of of PVA PVA______________________________________Release of 1st film 4 1(min.)Release of all films 10 9(min.)______________________________________ Approximately 100% of the original PLEXAR coating was recovered from the water. Upon microscopic examination, the recovered coating was determined to be essentially fiber-free. Having described the invention in its preferred embodiments, it will be recognized that variations of the invention by those skilled in the art are within the spirit and scope of the appended claims.

The specification discloses a multilaminar paperboard composite having improved recyclability and methods for forming and recycling the paperboard composite. The paperboard composite comprises a paperboard substrate having two surfaces, a highly alcoholized polyvinyl alcohol binder layer adjacent at least one surface of the paperboard substrate and a polyethylene polymeric layer bound to the polyvinyl alcohol layer. The highly alcoholized polyvinyl alcohol layer is present in an amount of from about 2 to about 12 pounds per 3000 square feet of substrate.

CROSS-REFERENCE TO RELATED APPLICATION This application claims benefit of U.S. Provisional Patent Application Ser. No. 61/415,540, filed on Nov. 19, 2010, and entitled, “Method for Active Cooling of Downhole Tools Using the Vapor Compression Cycle,” which is incorporated by reference herein in its entirety. FIELD Embodiments described herein generally relate to methods, systems and apparatus for using the vapor compression cycle in the active cooling of downhole tools and equipment. Embodiments of the present invention may be utilized in oil, gas, geothermal, water, and CO 2 wells, as well as any subsurface application known to one skilled in the art. BACKGROUND The oil and gas exploration and production industry is likely to drill and produce deeper and hotter wells, with wells with a reservoir temperature above 150° C. forecast to increase. In general, these types of wells are considered a high pressure high temperature, or HPHT, environments. In addition, an increasing number of Ultra HPHT (high pressure high temperature with the temperature above 205° C.) wells are likely to be drilled in the future. Using conventional technologies, downhole tools experience high failure rates at temperatures above 160° C. At this time, there is a limited catalog of electronic components which can reliably operate above 150° C. Therefore, providing active/passive cooling for electronics is one of the options for extending the operation and reliability of downhole tools such that they may be more effectively used in HPHT and Ultra-HPHT regimes. Passive methods of cooling downhole tools provide cooling for a short duration as they provide a fixed capacity for heat absorption from the tool. If the tool is likely to be exposed to HPHT or ultra HPHT conditions for long duration, then active cooling methods need to be used. Active cooling methods use electric power to reject heat absorbed from the tool at lower temperatures to the wellbore fluid (or the formation) at a higher temperature. SUMMARY Embodiments relate to a method of and apparatus for cooling equipment including exposing a fluid at a temperature T and pressure P to a surface in communication with electronic components mounted on a tool chassis, compressing the fluid to a temperature T 1 and pressure P 1 , exposing the fluid to a surface in communication with liquid or gas or both external to the tool wherein the fluid after exposure to the surface is at a temperature T 2 and pressure P 2 , and allowing the fluid to expand to a temperature T 3 and pressure P 3 wherein the equipment is a tool in a subterranean formation and T is less than T 2 and P is less than P 2 . Embodiments relate to an apparatus and methods for cooling oil field services tools including a tool that is in communication with a fluid that conducts heat from the tool to the fluid, a compressor that accepts fluid from the tool, a heat exchanger that accepts fluid from the compressor and that rejects heat from the fluid to the surrounding fluid or formation, and a valve or orifice to accept fluid from the compressor and to return fluid to the chassis within the tool wherein the compressor is controlled by a controller and the controller accepts temperature information from the tool and the surrounding fluid or formation. Embodiments relate to a method and apparatus for cooling an oil field services tool including exposing a fluid to a tool comprising electronic components, compressing the fluid in a compressor, exposing the fluid to a surface in communication with liquid or gas or both external to the tool, allowing the fluid to expand, and controlling the compressor using a temperature of the liquid or gas or both external to the tool. In some embodiments, the compressor includes a variable frequency drive and/or a temperature measurement of the surrounding formation and/or wellbore. In some embodiments, the fluid is water, brine, drilling mud, and/or formation fluid. In some embodiments, the fluid is paste, liquid, and/or pressurized gas. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a thermodynamic representation of the reverse-Brayton cycle. FIG. 2 is a schematic of the reverse-Brayton cycle. FIG. 3 is an Aspen HYSYS simulation of an ideal reverse-Brayton cycle. FIG. 4 is an Aspen HYSYS simulation of a practical reverse-Brayton cycle. FIG. 5 is a view of a thermodynamic representation of a Vapor Compression cycle. FIG. 6 is a schematic of a Vapor Compression Cycle. FIG. 7 is an Aspen HYSYS simulation of an ideal VCC. FIG. 8 is an Aspen HYSYS simulation of a practical VCC. FIG. 9A shows a delta chassis with electronic components mounted to the chassis and FIG. 9B shows a cross-sectional view of the delta chassis located within a tool housing. FIG. 10 is a figure drawing of a heating jacket. FIG. 11 is a plot of chassis temperature as a function of time for a steam inlet pressure of 307 psig and a jacket temperature of 200° C. FIG. 12 is a plot of a chassis temperature as a function of time for a steam inlet pressure 360 psig and a jacket temperature of 200° C. FIG. 13 is a plot of a chassis temperature as a function of time for a steam inlet pressure 480 psig and a jacket temperature of 250° C. DETAILED DESCRIPTION The techniques used for cooling downhole tools in high temperature environments may be broadly classified in two—passive cooling and active cooling. Passive Cooling As the name suggests, this class of thermal management does not use energy or electric power to provide cooling. Commonly vacuum jacketed pipes, high insulation materials, and phase change materials are used for reducing heat ingress from the high temperature environment of the wellbore while providing a mechanism for cooling the components inside the tool body. However, this strategy can only provide limited cooling capacity for tools in a high temperature environment. It is a useful strategy for some downhole tools that are only deployed for a short duration. However, for certain tools that have longer mission profiles at high temperatures, the options for avoiding failure of electronic boards are either providing active cooling of standard electronic components or specially designed high temperature electronic components. Active Cooling It is useful to define the problem in standard terms. Consider Tc as the temperature at which we need to maintain the tool, while the wellbore temperature is Th. Let Q is sum of the rate of heat leaked through the housing to the tool and the rate of heat generated on the chassis (where the electronic components are mounted), and W is the rate of work done on the system. It is possible to construct a thermodynamic cycle (commonly referred to as a heat pump) to absorb heat Qc at a cold temperature Tc and reject it at higher Th using W as the work done. Note that the Clausius statement of the second law of thermodynamics states that heat generated cannot spontaneously flow from a material at a lower temperature to a material at a higher temperature. Therefore, any embodiment of a strategy to absorb heat continuously at Tc and rejecting it at Th will require input work or electric power. It is important to choose the most appropriate thermodynamic cycle and working fluid for absorption of heat from the tool and dissipation of heat to the drilling mud. It would be appropriate to choose a thermodynamic cycle with the highest possible efficiency so that the power consumption downhole is minimized. There are several techniques that may be used to provide this cooling. These include thermoelectric devices, sterling or pulse tube refrigerators, thermoacoustic coolers and our cycle of choice, the vapor compression cycle. Thermoelectric devices are generally used for local area cooling/heating and generally have low coefficient of performance (COP, defined as Qc/W). Thermoacoustic coolers, sterling cryocoolers and pulse tube refrigerators can all be described using the reverse-Brayton cycle (shown in FIG. 1 ) as each of these processes includes the following steps. 1. Adiabatic compression of the gas. The fluid is adiabatically compressed using shaft work Ws with a concomitant temperature increase at stage 3 to a temperature higher than Th. 2. Isobaric heat transfer. At constant pressure, the fluid is cooled in a heat exchanger to a temperature T 4 after rejecting heat Qh to the ambient. 3. Adiabatic expansion. The fluid is expanded either across a turbine or a piston at constant entropy. This expansion cools the fluid to temperature T 1 , which is less than Tc. 4. Isobaric heat transfer. As the fluid temperature is less than Tc, it absorbs heat Qc from the source, gradually increasing the fluid temperature to T 2 , which is just below Tc. FIG. 1 provides a thermodynamic representation of the reverse-Brayton cycle. Line 101 is cooled fluid, line 102 is after heat pickup, line 103 is compressed fluid and line 104 is after heat rejection. This cycle, as described is completely reversible as both compression and expansion are reversible. Therefore, it is the perfect embodiment of an ideal heat pump. Consider Tc=150° C. and Th=250° C. For a heat pump, the ideal or Carnot COP is defined as Tc/(Th−Tc)=4.12 for our process. FIG. 2 is a schematic of the reverse-Brayton cycle. 201 represents work input, W s , 202 represents heat rejected, Q h , T h , 203 represents isentropic expansion, and 204 represents heat absorbed, Q c , T c . We simulated the above process using a process simulator Aspen HYSYS. The simulation results are shown in FIG. 3 . FIG. 3 is an Aspen HYSYS simulation of an ideal reverse-Brayton cycle. The following table summarizes some components of the figure. Title Heat Flow [W] 301 Power In 50.58 302 To Drilling Mud 42.73 303 Tool Heat 173.6 304 Shaft Power 374.0 305 To Drilling Mud 2 181.4 Allowing for a tool heat pickup of 173.6 W at 150° C., we chose a temperature at T 1 of 149.1° C. (since we needed a temperature below 150° C. for sensible heat transfer to the fluid). We assumed an ideal heat exchanger with the outlet fluid stream after absorbing heat from the tool at 150° C. We also assumed an ideal exchanger for cooling the compressed gas stream (T 3 to T 4 being 262.1° C. to 250° C., and 252.9° C. to 250° C.), which is compressed in two stages. The first stage of compression uses the work recovered in expansion of the gas stream from stage 4 to stage 1 and the second stage of compression uses an electric motor driven compressor (with input power Ws). The expansion across expander K-101 is considered to be ideal with an adiabatic efficiency of 100%. This cycle is thus simulated to be as ideal as possible in a conventional simulator. The calculated COP for this process is 3.432, which is close to the Carnot COP of 4.12. In principle, a COP of 4.12 should be achievable if we increase the temperature at stage T 1 from 149.1 to as close to 150° C. as possible. Practically, it would entail a much higher flow rate and an extremely large ideal heat exchanger E-101. The current example suffices to prove our point that, theoretically, the reverse-Brayton cycle and its many manifestations as sterling, pulse tube or thermoacoustic coolers are the most efficient heat pump cycle. However, in a practical manifestation of this cycle, shown in FIG. 4 , it is clear that the practical COP achievable is nowhere close to the theoretically estimated COP or the Carnot COP. FIG. 4 is an Aspen HYSYS simulation of a practical reverse-Brayton cycle. The following table summarizes some components of the figure. Title Heat Flow [W] 401 Power In 391.2 402 To Drilling Mud 403.2 403 Tool Heat 126.6 404 Shaft Power 253.0 405 To Drilling Mud 2 114.5 In this cycle, we chose Argon as the working fluid. T 1 was chosen as 30.57° C. to get a reasonable flow rate for Argon. After heat pickup of 126.6 W from the tool, the temperature increased to 140° C., an approach of 10° C. to Tc of 150° C., so that we may be able to design a reasonable heat exchanger. The compressor and the expander adiabatic efficiencies were fixed at 75%, which is realistic. Fluid temperatures after rejecting heat to the wellbore at 250° C. were set at an approach of 10° C., to 260° C. The COP for this practical cycle was calculated to be only 0.3236, almost a factor of ten below the ideal cycle and less than 10% of the Carnot COP. As discussed previously, we selected the vapor compression cycle, or VCC. The vapor compression cycle is shown in red lines in the T-S space in FIG. 5 . FIG. 4 provides a thermodynamic representation of a Vapor Compression cycle with the following reference numerals. 501 Saturated Vapor 502 Superheated Vapor 503 Saturated Vapor 504 Saturated Liquid 505 Liquid+Vapor A schematic for this cycle is also shown in FIG. 6 , with the numbered stages corresponding to those shown on the T-S phase diagram in FIG. 1 with the following reference numerals. 601 Work Input, W s 602 Heat rejected, Q h , T h 603 Isenthalpic, W s =0 604 Heat absorbed, Q c , T c Starting at stage 1 , or saturated vapor, the fluid is compressed using a suitable compressor to point 2 , labeled “Superheated Vapor”. This process requires work input, shown as Ws in FIG. 6 . Note that, in this example, the compression is shown as occurring in a single stage for simplicity. In practice, this compression is likely to be in several stages. At point 2 , the temperature of the fluid is higher than the elevated ambient temperature. Therefore, using a suitable heat exchanger, the temperature of the fluid may be cooled close to the ambient temperature T h . The fluid needs to chosen such that it exists as a saturated vapor at these conditions. Pressure for stage 2 is chosen such that the fluid exists as a saturated vapor at pressure P 2 (pressure at stage 2 ), and temperature T h (temperature at stage 3 and 4 ). The fluid continues to cool beyond this point to stage 4 , or to the saturated liquid stage. In a single phase, transition from saturated vapor to saturated liquid takes place at a constant temperature, shown in FIG. 5 as a horizontal line between stage 3 and 4 . The fluid is then iso-enthalpically expanded across a valve and the pressure drops to P 5 (which is same as P 1 ). The temperature of the expanded fluid drops to T 5 , which is a few degrees below Tc to facilitate heat pickup from the tool maintained at Tc. At stage 5 , the fluid exists as a vapor-liquid mixture, which is mostly liquid. As mentioned before, the amount of liquid in this mixture may be estimated by using the lever rule within the boundaries of the bell shaped curve that defines the saturated liquid and the saturated vapor curves. As the fluid picks up heat (or cools the electronic chassis on the tool), the relative amount of vapor increases in this vapor-liquid mixture. The heat rejected by the downhole tool is absorbed as the latent heat of vaporization so the heat pickup by the fluid occurs at a constant temperature. At the end of the heat pickup, at stage 1 , the fluid has no liquid phase left and is shown in FIG. 5 on the saturated vapor curve. This cycle is then repeated as the tool is continuously cooled. An ideal version of this cycle was simulated using Aspen HYSYS and the results are shown in FIG. 7 . FIG. 5 is an Aspen HYSYS simulation of an ideal VCC with the following reference numerals and heat flows. Title Heat Flow [W] 701 Power In 34.84 702 To Drilling Mud 145.5 703 Tool Heat 110.7 In this instance, the compressor adiabatic efficiency was assumed to be 100% and the heat exchangers were assumed to be 100% efficient, as for the ideal reverse-Brayton cycle. The ideal cycle COP is calculated to be 3.178, lower than the ideal reverse-Brayton cycle COP as expansion across the valve VLV-100 is not adiabatic (or iso-entropic of reversible). It is iso-enthalpic, or, in other words, there is loss of entropy associated with this process. About 110.7 W of heat are absorbed from the tool for this simulation. A practical version of this cycle was simulated using Aspen HYSYS and the results are shown in FIG. 8 . FIG. 8 provides an Aspen HYSYS simulation of a practical VCC with the following reference numerals and heat flows. Title Heat Flow [W] 801 Power In 57.28 802 To Drilling Mud 163.9 803 Tool Heat 106.6 The compressor K-100 adiabatic efficiency was set at 75% and a 10° C. approach was used for all heat exchangers. The temperature of stream 4 (past the heat exchanger E-100) is cooled to 260° C. as Th is at 250° C. The two-phase fluid, stream 5 is introduced to the tool heat exchanger (e-101) at 140.7° C. It picks up 106.6 W of heat from the tool. The COP for this cycle is calculated to be 1.862, or 45.2% of the Carnot COP. Therefore, it is obvious from the preceding discussion that although the reverse-Brayton cycle represents the highest achievable COP for an ideal cycle, for a practical thermodynamic cycle using components with reasonable efficiencies, the VCC represents the best option for cooling downhole tools. Several versions of downhole cooling cycles are discussed for cooling downhole tools in U.S. Pat. No. 5,701,751, U.S. Pat. No. 6,769,487, U.S. Pat. No. 6,978,828 which are incorporated by reference herein. This discussion is directed toward methods, systems and apparatus for active cooling of downhole tools using the vapor compression cycle. Additional methods, systems, apparatus for active cooling of downhole tools using the vapor compression cycle are further detailed in a section below entitled “Example Implementations.” These recited additional features, systems, methods and/or apparatus represent a non-exhaustive potential implementation and are recited for illustrative purposes. Refrigerant Choice The choice of a suitable refrigerant for this cycle requires a fundamental thermodynamic analysis. Most Freon based refrigerants commonly used for room temperature cooling are not suitable as they have low critical temperatures. For this particular application, it is useful to examine this cycle in the Temperature-entropy (or the T-S) space, shown in FIG. 5 . The region to the left of the blue curve is labeled as “Liquid”. The fluid exists as a liquid in this space, as a saturated liquid on the blue curve and as subcooled liquid to the left of the blue curve. Under the bell shaped curve, identified by the blue curve to the left and the cyan curve to the right, is the two-phase region, identified as the “Liquid+Vapor” space. Isobaric, or constant pressure curves are shown, starting in this region and extending into the “Vapor” region on the right of the cyan curve. As we move along an isobaric curve from the blue, or the saturated liquid curve, to the cyan or the saturated vapor curve, the relative fraction of vapor increases from zero to 100%. At any intermediate point, the relative amount of liquid or vapor may be calculated using the lever rule. At the apex of the bell shaped curve, is a point labeled the “Critical Point”. This represents the maximum or critical temperature (in the T-S space) at which the vapor and liquid phases may coexist. There is an equivalent pressure, referred to as the critical pressure, above which the two phase region does not exist. This critical pressure curve is shown on FIG. 5 as a dotted cyan curve. In this cycle, there are several constraints on the choice of a fluid. Some of these are listed below. 1. The critical temperature should be greater than the highest temperature where we wish to deploy these tools, preferably with a safety margin of approximately 50° C. 2. The triple point, or where the fluid may form a solid, should be at least approximately 50° C. below Tc, or the temperature where we wish to cool the tool. We then conducted a search on fluids with a critical temperature between 300-1000° C. and a Triple point temperature below 100° C. The fluids with such properties include water, duodecane, propylcyclohexane, decane, methyl linoleate, methyl linolenate, methyl oleate, methyl palmitate, methyl stearate, nonane, toluene and heavy water. Of these fluids, water is the environmentally friendly, available freely and has a high latent heat of vaporization. Therefore, for our purpose, we choose this fluid for the vapor compression cycle. Experimental Implementation This thermodynamic cycle was demonstrated in a wireline tool. FIG. 9A shows a delta chassis 902 with electronic components mounted 904 to the chassis. The electronic circuit boards 904 are mounted on three rectangular outer faces 906 , 908 , 910 of a triangular tube chassis (also called the delta chassis) 902 . The delta chassis 902 is segmented into four zones with three faces per zone and four faces per side as shown in FIG. 9A . Heating elements and thermocouples were installed on these faces to simulate heat generated from electronic components during operation. The chassis 902 is wired up with a thermocouple on each face and a 64 Watt heater around each Zone. These heaters are wired together in parallel and are controlled by a variable transformer to give a total distributed heat load across the delta chassis ranging from 30-190 W. FIG. 9B shows a cross-sectional view of the delta chassis 902 located within a tool housing 912 of the wireline tool. The delta chassis 902 is made of 6061/6063 aluminum with four flow lines 914 going through the body for refrigerant circulation. The refrigerant lines are shown in FIG. 9B by the holes shown on the enlarged end view. The orientation of the coolant flow lines 914 is such that flow can go along the three outer lines and return through the center line. To simulate the high-temperature downhole environment, the chassis is put inside a vacuum insulated pipe, and the pipe is heated to simulate heating from the formation in which the tool may be operating. The pipe is heated by two 4.5 ft jacket heaters. As shown in FIG. 10 , each heater is broken up into two zones for individual temperature control of each zone. Both heaters are rated at 1200 W. These heaters are controlled by a temperature controller. The cooling system is designed to provide compressed steam (as a refrigerant) to cool the delta chassis. An expansion valve was used to allow the steam to decompress as it enters the system. During operation, the system operates with the internal fluid temperature maintained at 140° C. The system is charged with water to 38.3 psig, corresponding to saturated vapor/liquid conditions at 140° C. for water, and the external heating jackets are turned on. In order to demonstrate the feasibility of the vapor compression cycle, testing has been done for the two temperatures, 200° C., and 250° C. When the refrigerant is able to absorb the heat that is being generated on the chassis, the zone temperatures remain close to 140° C., the saturated temperature of steam at 38 psig, the pressure in the chassis tubes. Once the chassis generated heat load exceeds the ability of the refrigerant to absorb the heat, Zone 4 begins to increase in temperature and the other Zones 3 , 2 and 1 subsequently follow suit. The experimental results are shown in FIGS. 11, 12, 13 and 14 . FIG. 11 shows the temperatures in the four zones of the chassis as a function of time. The steam flow rate is set at 5 ml/min and the jacket temperature is maintained at 200° C. Steam is introduced at a pressure of 307 psig to the expansion valve. At a time before 12:00 p.m., the four zonal temperatures could be maintained at close to 140° C. with this flow rate of steam. At 12:00 p.m., 55 W of heat was applied to the chassis using resistive heaters. As can be seen from the graph, it was not possible for to keep the chassis temperatures constant, and Zone 4 A temperature started increasing shortly thereafter. After a few minutes, Zone 3 A temperature also started increasing. The heat generated on the chassis was decreased to 50 W at 2:24 p.m. and all zonal temperatures started to ramp down to the original temperatures, close to 140° C. Therefore, for this experiment, we conclude that 50 W of heat generated on the chassis, in addition to heat leaked from the outer jacket through the vacuum jacketed pipe, can be absorbed by a steam flow rate of 5 ml/min. The conditions are identical (to those in FIG. 11 ) for the next experiment, shown in FIG. 12 . Steam inlet pressure was set at 360 psig. Under these conditions, the temperatures of the four zones are maintained close to 140° C. A heat load of 190 W was applied to the chassis and the chassis temperatures remained constant. Therefore, with a steam flow rate of 9 ml/min, a minimum of 190 W can be absorbed from the chassis, in addition to heat leaked from the outer jacket. FIG. 13 shows the temperature versus time profile for chassis thermocouples for an ambient temperature of 250° C. Steam was introduced at a pressure of 480 psig. As is clear from this graph, 60 W of chassis generated heat (plus heat flux through the vacuum-jacketed pipe) can be absorbed with a steam flow rate of 7 ml/min and 70 W of chassis generated heat (plus heat flux through the vacuum-jacketed pipe) can be absorbed with a steam flow rate of 8 ml/min.

A method of and apparatus for cooling equipment including exposing a fluid to a tool comprising electronic components at a temperature T and pressure P, compressing the fluid to a temperature T 1 and pressure P 1 , exposing the fluid to a surface in communication with liquid or gas or both external to the tool wherein the fluid after exposure to the surface is at a temperature T 2 and pressure P 2 , and allowing the fluid to expand to a temperature T 3 and pressure P 3 wherein the equipment is a tool in a subterranean formation and T is less than T 2 and P is less than P 2 . Apparatus and methods for cooling oil field services tools including a fluid that conducts heat from the tool to the fluid, a compressor that, a heat exchanger that accepts fluid from the compressor and that rejects heat from the fluid, and a valve or orifice.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for removing loose debris from streets and other surfaces. Particularly, the present invention relates to snow or ice removal from regular and irregular surfaces. More particularly, the present invention relates to a system that can be configured to perform various ground cleaning operations. More particularly yet, the present invention relates to a snow removal system that fractures the snow covering a surface, lifts the fractured snow from the surface, and discharges it through an impeller/discharge system. Most particularly, the present invention uses a stiff but flexible stepped triple finger mechanism to fracture and lift the snow and deliver it to an impeller assembly that transfers the snow and laterally discharges it, at an adjustable height above the surface from which it is expelled. 2. Description of Prior Art Although the utility of the present invention is not limited to snow removal, the relevant prior art lies in the field of snow removal mechanisms. Among the many different means for removing snow from ground surfaces snowplows are the best known. Nevertheless, snow removal by snowplow has a number of inherent disadvantages. A snowplow typically requires several passes to clear a roadway of snow. In the first pass, it clears a swath, discharging the snow to the side of the plow, thereby creating snowbanks that narrow the roadway and impair visibility for vehicle operators or pedestrians. In a subsequent pass or passes, the plow works at pushing the snowbank further away from the roadway. Furthermore, highway snowplows typically require a certain minimum forward speed if the plows are to impart to the snow the velocity needed for the snow to travel across the face of the plow. In congested traffic conditions in which the snowplow is prevented from maintaining this minimum speed, snow spillage may occur at the edge of the plow not intended to discharge snow, leaving ridges of snow in the middle of the roadway or causing the vehicle to stall. Also, snowplow blades are straight and rigid, designed to remove snow from regular surfaces. When they contact fixed protrusions from the surface, these blades may become bent or damaged in other ways, requiring costly repair or replacement. Also, the plow blade does not remove the snow from the ground cleanly, but rather, leaves surface recesses filled with snow. Snowblowers have certain advantages over plows: they do not require a minimum forward velocity of the prime mover in order to move the snow and, depending on the orientation of the discharge outlet and the throw speed, they may avoid creating snowbanks at the roadside. Yet, there are also disadvantages inherent to snowblowers, existing in all of their many types. Snowblowers typically engage the snow by means of cutters, brushes, or augers, and transport the snow to a blower unit which discharges it to either side of the snowblower at some distance from the roadway. Cole (U.S. Pat. No. 2,103,514; 1937) teaches a system that uses a pair of rotary cutters to engage and then transport the snow or ice to a centrally located blower unit, which then discharges the snow or ice to either side of the vehicle as desired. Another system teaches the use of a rotary drum having blades located around its periphery to cut and lift snow and convey it to a discharge unit Maxfield et al. (U.S. Pat. No. 5,209,003; 1993). The rigidity of augers or cutters, as taught by the systems of Cole or Maxfield et al. creates several difficulties. For one thing, the leading edge of an auger or a rotary cutter is necessarily exposed to allow engagement with the snow; these rigid, churning augers or cutters make such snowblowers inherently dangerous to use. Furthermore, rigid augers and cutters can damage—or be damaged by—roadway protrusions, such as manhole covers or bridge joints, and, consequently, must be operated at some distance above the level of the surface to be cleared. This practice leaves residual snow on the surface. This means that systems that use augers or cutters can be used only in conjunction with other snow removal means, physical or chemical, if the snow is to be completely removed. Snow blowers do exist that use brushes rather than rigid augers. E.g., Klauer (U.S. Pat. No. 2,941,223; 1960) teaches a manually operated system that uses two spiral brushes, oppositely wound around a rotating shaft, to transport snow to the center of the shaft. Alternatively, Maisonneuve et al. (U.S. Pat. No. 3,886,675; 1975) teaches the combined use of a rotating brush and an auger to engage snow and transport it to the blower unit. Rotating brushes, unlike rotating cutters and augers, can be operated in direct contact with the ground surface. Brushes, however, have a disadvantage in that the bristles in the brushes are round and, thus, only the snow particles that hit the leading edge of the bristles are propelled forward. All others are deflected laterally to varying degrees. Brushes also require a great deal of power to engage and lift the snow. This is because, typically, every bristle contacts the ground and, thus, every bristle bends, its tip contacting the ground. This results in the leading edge of the bristle actually facing downward before the bristle tip starts its desired forward and then upward movement as the tip loses contact with the surface. As a result, the snow is initially driven downward before it is propelled upward and forward. This results in a packing of the snow, making it more resistant to being passed through the rest of the device. Furthermore, since all the bristles drag on the ground, they encounter a frictional force that works against the direction of the brush rotation. This increases the power demanded to maintain that rotation at an effective rate. As described above, snowblowers with brushes, augers or rotary cutters typically transport the snow to a centrally situated blower unit for expulsion. This means that the snow is handled for an extended period of time, as it travels from the outer edge of the snow collection means to the center, or, when dual snowblowers are used, as it travels from the center of snow collection device to the outer edges. The longer the snow remains in the system, the greater the volume of snow that is being handled or transported at any given time. Thus, snowblower systems must be designed to accommodate these large volumes and provided with the power required to move them. Also, the fact that snowblowers pack the snow as it is handled means that more power is required to transport the snow then would be the case with loose fluffy snow. Furthermore, the high-density, packed snow often causes the equipment to jam, leading to interruptions and potentially hazardous operations to clear the device. Snow or debris removal systems are generally dedicated systems, i.e., a snow removal system is designed to remove only snow, a street sweeper is designed to remove only dirt and loose debris from the ground. As a consequence, cities, towns, and other entities that must be concerned with removing snow or debris from ground surfaces are required to invest in multiple costly devices to perform various necessary ground cleaning operations. It would be of great advantage if a system for removing snow and other debris could be rapidly and easily reconfigured as required to perform various ground surface cleaning operations, such as removal of frozen slush or fallen leaves or other loose debris, in addition to snow removal. Therefore, what is needed is a snow removal device that will cleanly and safely remove snow from ground surfaces and discharge the snow without creating snowbanks that narrow the roadway or impair visibility. What is further needed is such a device that will fracture the snow into small, light units, thereby improving the operating speed, efficiency, and safety of such a device. What is yet further needed is such a device that will cleanly remove snow from irregular ground surfaces. What is still further needed is such a device that can be rapidly and easily reconfigured to perform various ground surface cleaning operations. BRIEF SUMMARY OF THE INVENTION It is an object of the present invention to provide a snow removal device that will cleanly and safely remove snow from ground surfaces and discharge the snow without creating snowbanks that narrow the roadway or impair visibility. It is a further object of the invention to provide such a device that will fracture the snow into small, light units. It is yet further an object of the invention to provide such a device that will remove snow from irregular ground surfaces. It is still further an object of the invention to provide a device that can be rapidly and easily reconfigured to perform various ground surface cleaning operations. The apparatus of the present invention provides a novel means for cleanly and efficiently removing snow and other debris from ground surfaces, regardless of whether the surfaces are level. The equipment is safer to operate than either snowplows or auger-using snowblowers, it is easily accessible for cleaning and maintenance, and requires a minimal amount of operating energy. The basic units of the system of the present invention are a novel rotating pick-up assembly mounted in close proximity to an impeller assembly. The system can be contained on its own chassis and pushed in front of, or pulled behind, a prime mover such as a truck, or can be self-propelled, or mounted on another vehicle. In its Preferred Embodiment, the removal system of the present invention is mounted on a floating chassis attached to and suspended from a “fixed” chassis that can be pulled or pushed. The fixed chassis is designed to support floating chassis of varying widths. The moving components of the system are powered by a hydraulic power unit, or other power means, that can be incorporated into the system, or provided externally. The basic units of the removal system are a pick-up assembly, an impeller assembly, and a discharge tube. The pick-up assembly consists of a drum array mounted on a drum shaft that runs parallel to the ground surface and perpendicular to the direction the system is intended to move. The drum array may be formed from a plurality of interconnected drums, or it may consist of an individual drum. Most importantly, each drum carries an array of finger modules and each finger module includes an array of flat fingers, each of which is an elongated, thin element. Fingers offer distinct advantages over snow removal equipment that uses plow blades, augers, cutters, or rotary brushes. Made of a stiff, yet flexible material, they will flex when they come into contact with fixed protrusions on the surface, unlike rigid plow blades, augers or cutters. As a result, the fingers are much less likely to be damaged by objects on road surfaces; also, they will not damage protrusions on the ground surfaces such as manhole covers and bridge joints. This finger module is the heart of the present invention, which thereby provides advantages over rigid, straight-edged plow blades, rotary brushes and augers and cutters with respect to its ability to sweep surfaces clean of debris, including snow. In the Preferred Embodiment, these stepped finger modules have three fingers: a leading finger, a middle finger, and a trailing finger, each successively longer. In the operating position, the distance of the pick-up assembly from the ground is adjusted so that the middle finger just grazes the mean level of the ground surface. With the drum rotating in a direction that causes the snow to be flicked forward to the impeller openings, the leading finger does not touch the road surface at all, but rather strikes the snow at some short distance above the ground. As this leading finger hits the snow, it fractures it, i.e., it breaks the snow into small particles and, as the finger continues through into its forward and upward rotation, it lifts the snow particles into the vicinity of the impeller assembly intake. With the apparatus operating in this manner, the middle finger just grazes the ground surface and conveys forward and upward the snow that the leading finger left behind. The trailing finger, having a length greater than the distance needed to reach the ground, flexes and drags when it contacts a flat surface. Thus, it is able to scoop snow out of depressions in the road or ground surface. In short, the leading finger fractures and displaces the snow down to within an inch or so above the ground. Because it is just moving through snow, without scraping against the road surface, this lead finger encounters minimal “back forces” and, consequently, presents minimal drag on the drum rotation. The middle finger fractures and lifts the snow left by the leading finger, also transmitting little back force to the drum, since it just grazes the surface and does not have to flex and drag on the ground. The trailing finger, when it contacts the ground, does flex and scrape the ground, thus creating a back force on the drum. However, since it is not lifting any significant amount of snow (the bulk of the snow having already been cleared away by the leading and middle fingers), the ground resistance is about all that contributes to its drag. Thus, in contrast to snowblower systems or plows that compact the snow in the pick-up process, the pick-up assembly of the present invention breaks the snow into small units while it lifts it from the surface, cleanly and with a minimal force on the drum. The fingers offer a further advantage in that individual fingers can easily be replaced when they eventually become worn or damaged, in contrast to the large snowplow, auger, or brush assemblies, each of which can be very costly to replace. The snow removal device of the present invention is intended to be used in connection with new snowfall as well as with packed snow. In normal operating mode, the lower half of the drum is rotating in the direction of travel of the system, with the shorter finger being the leading finger. For light fluffy snow, the direction of the rotation of the drum can easily be reversed, so that the lower half of the drum is rotating opposite the direction of travel. In this mode of operation, the longer finger becomes the leading finger, with the middle and shorter fingers providing a stiffening and strengthening of the leading finger. The snow is swept backward and upward, propelled around the drum, and driven from above into the impeller assembly. The advantages of operating the system in this reverse mode are twofold: the system can be operated at greater travel speeds, and less power is required to operate the drum. The impeller assembly includes one or more impeller units. In the Preferred Embodiment, four impeller units are arranged in an array such that an axis that passes through the centers of them all is perpendicular to the direction of travel of the snow-removal apparatus and parallel to the pick-up assembly's drum shaft. The impeller assembly is mounted on the floating chassis adjacent to the pick-up assembly. The impellers are similar to fans that move large volumes of air. In this case, the action of the impellers creates a pressure gradient such that all snow brought near the intakes is sucked into them. Each impeller unit includes an impeller blade array attached to an impeller shaft and to an impeller base plate, and an impeller chamber formed by an impeller chamber cover and impeller chamber walls. The impeller blades rotate in impeller chambers and, as an impeller blade approaches the opening between the chamber and the discharge tube, the rotational impeller action flings the snow into the discharge tube whence It is expelled from the system. The direction of impeller rotation is reversible, therefore the snow can be discharged to either side of the system, as desired. The discharge tube lies in the same plane and is parallel to the impellers and, thus, discharges the snow transversely at a relatively low height, using to advantage the fling momentum of the impellers and reducing the danger of snow cloud formation. In normal operation, the plane of the impeller intake is tilted only slightly upward toward the pick-up assembly; however, the section of the floating chassis that supports the impeller/discharge assembly can be pivotally attached to the section of the floating chassis that supports the pick-up assembly so as to allow the plane of the impeller intake to be tilted at a steeper angle. Increasing the angle of the plane of the impeller assembly/discharge tube relative to the ground brings the impeller intake closer to the pick-up assembly, thereby decreasing the distance the snow must travel between the exit point of the pick-up assembly and the impeller assembly intake. This is advantageous when clearing wet snow. Increasing the tilt of the impeller intake plane also raises the height of the discharge tube, changing the height and angle of discharge, which may be desired in certain conditions. The use of multiple impellers has distinct advantages over systems that utilize only a single or two blower units. The pick-up assembly does not need to transport the snow as far to deliver it to the impeller unit because of the proximity of the impeller assembly intake to the pick-up system. Also, the “negative” pressure that is created along the length of the pick-up assembly by the impeller action assists the delivery process by sucking the snow into the impellers. Furthermore, the snow is handled for a much shorter period of time before it is dumped into the discharge tube and, consequently, the use of multiple impellers reduces the volume of snow that is within the system at any one time. Thus, the impeller assembly handles the snow more efficiently and can be much more compact in design relative to other known snowblower systems of equivalent capacity. Separate housings enclose the pick-up assembly and the impeller assembly/discharge tube so that during operation all sides, with the exception of the bottom of the pick-up assembly, are enclosed. This enhances the operating safety of the system because no moving parts of the apparatus are exposed during operation. Removable access covers can be opened to provide access to the pick-up assembly and the impeller assembly and discharge tube from above, making the assemblies readily accessible for cleaning and maintenance. The apparatus of the present invention has three operating positions: an idle position in which the fingers of the pick-up assembly only reach to within one or two inches of ground level; a working position in which the middle finger just grazes the ground; and a transport position in which the entire device is raised and supported so that the fingers only come to within six to eight inches of the ground. For cleaning and maintenance operations, the floating part of the apparatus can be raised still further above ground level or the fixed chassis can be lifted from above to provide easy access to the pick-up assembly and the impeller assembly and discharge tube. The device of the present invention is a versatile system that can be used for purposes other than snow removal. For example, the pick-up assembly with the finger modules can also be used for cleaning streets of debris in the summer. Furthermore, the drum with the finger modules can be easily and conveniently removed and replaced with another drum, such as a drum fitted with special blades or chains for removing ice, or with a brush for removing sand from the road in the spring. Furthermore, the versatility of the system is enhanced by the fact that the fixed chassis of the system can support varying widths of a floating chassis and the fact that the drum can rotate in a forward or reverse direction relative to the direction of translational travel. In summary, the present invention includes a pick-up assembly and an assembly that includes an impeller assembly and a discharge tube, both of which are mounted on a floating chassis that in turn is mounted on a fixed pullable or pushable chassis, with the drum of the pick-up assembly and the blades of the impeller assembly driven by hydraulic motors mounted on the floating chassis. All moving parts of the system are enclosed in housings or under hoods during operation, greatly improving the safety of operating such a system. As the drum in the pick-up assembly rotates, the stepped, triple-finger modules fracture the snow and lift it into the vicinity of the impeller assembly, where it is sucked into the impellers and discharged to either side of the system through the discharge tube. The use of stepped fingers allows the snow to be broken up into small units, rather than be compacted, as is the case with snowplows and brush, auger, or cutter snowblowers. This offers several advantages: the snow is lighter and easier to transport, less power is required for its transportation, and the fracturing action of the fingers reduces the probability of the snow packing while being handled, thus increasing safety and efficiency. The use of flexible-yet-stiff fingers offers further advantages in that the fingers clean uneven road surfaces of snow efficiently and without damage to the snow removal equipment or to protrusions from the road surface such as manhole covers and bridge joints. The use of fingers is also cost effective, as the fingers can be replaced individually should they become worn or damaged. The use of multiple impellers provides a more efficient, compact design than the use of simply one or two impellers and also creates a suction force that aids in delivering the snow into the discharge assembly. Furthermore, the location of the discharge tube allows for relatively low transverse discharge, thus reducing the formation of snow cloud and improving visibility for other vehicles and pedestrians in the vicinity of the operating system. A device for removing snow or other debris from ground surfaces which has several different, easily and rapidly interchangeable drums, each configured to perform a certain ground cleaning operation, offers cost-saving advantages to entities that must acquire several different devices to perform the various typical cleaning operations on roads and other ground surfaces. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of the system, shown as it appears during operation, fully enclosed in housings and with access covers closed. FIG. 2 is a side view of the system, shown as it appears during operations, fully enclosed in housings and with access covers closed. FIG. 2 a is a schematic drawing of the drum mounting and drum motor drive. FIG. 3 is a perspective view of a finger module. FIG. 4 shows a drum shaft with finger modules. FIG. 5 shows a fully assembled drum array. FIG. 5 a shows a partially assembled drum array of the Preferred Embodiment. FIG. 6 is a frontal view of a bracket with finger modules. FIG. 7 is a top view of the system with housings and covers removed. FIG. 8 is a frontal view of the impeller assembly. FIG. 8 a is a top view of the chamber wall and blade set of an impeller unit. FIG. 8 b is a frontal view of the impeller blade attached to the impeller shaft. FIG. 9 is a perspective view of an impeller assembly and discharge tube. FIG. 10 is a partial cut-away view of the system according to the invention, showing the pick-up assembly, the impeller assembly, and the discharge tube. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In its Preferred Embodiment, the apparatus of the present invention is configured to be a snow removal system 1 FIG. 1 and FIG. 2 show the snow removal system 1 as it appears during operation. A pick-up assembly 4 is enclosed under a curved pick-up assembly housing 6 having a removable access cover 7 ; an impeller assembly 5 and discharge tube 70 are enclosed under an impeller assembly/discharge tube housing 8 having a removable access cover 9 . During operation, the pick-up assembly 4 picks up snow and conveys it to the impeller assembly 5 , which expels the snow into the discharge tube 70 whence it is discharged from the system 1 through discharge tube end 71 . As can be seen in FIG. 1 and FIG. 2, the sides and tops of the pick-up assembly 4 and the impeller assembly 5 are fully enclosed during operation, thus preventing any unintended contact of operators or pedestrians with moving parts of the system 1 . FIG. 10 is a partial cut-away view of the snow removal system 1 and illustrates the arrangement of the pick-up assembly 4 , the impeller assembly 5 , and the discharge tube 70 . The heart of the invention lies in the use of a finger module 33 as a snow pick-up device on the pick-up assembly 4 . As can be seen in FIG. 3, the finger module 33 of the Preferred Embodiment includes a triad of blade-like fingers including a long trailing finger 33 a , a middle finger 33 b , and a short leading finger 33 c . The fingers 33 a , 33 b , 33 c are fabricated of band or spring steel or any other material that is sufficiently strong to allow the fingers 33 a , 33 b , 33 c to fracture and lift snow, yet flexible enough to allow them to bend when they contact the ground or fixed objects. Referring again to the Preferred Embodiment, the fingers 33 a , 33 b , 33 c are approx. 1″ in width, the trailing finger 33 a is approximately 1″ longer than the middle finger 33 b and 2″ longer than the leading finger 33 c . Although the finger module 33 in the Preferred Embodiment has a triad of fingers, it is still within the scope of the present invention to have a pick-up drum 35 having a plurality of finger modules that include one or more fingers. Such a pick-up drum 35 is shown in FIG. 4 . FIG. 5 shows a fully assembled drum array 17 of the pick-up assembly 4 and FIG. 5 a shows a partially assembled drum array 17 a according to the Preferred Embodiment The drum array 17 contains a plurality of drums 18 a , 18 b , 18 c , . . . , a drum shaft 12 , and an inner shaft 12 a having shaft ends 13 . In the Preferred Embodiment, the drum shaft 12 is fabricated of schedule 80 steel pipe, 4″ in diameter and approx 87″ in length, but could be made of any suitable length and be fabricated of any other material that is strong enough to withstand the forces applied to the shaft. The drum shaft 12 is fitted over the inner shaft 12 a . This inner shaft 12 a is a solid steel shaft 2 {fraction (7/16)}″ in diameter that extends the entire length of the drum array 17 with shaft ends 13 fitting into support bearings 206 (not shown) mounted on the floating chassis 2 . FIG. 5 a shows a partially assembled drum array 17 a according to the Preferred Embodiment. A first drum 18 a is formed by mounting a first drum disk 20 a and a second drum disk 20 b rigidly on the drum shaft 12 and mounting a plurality of first brackets 27 a between the first drum disk 20 a and the second drum disk 20 b so that the plurality of first brackets 27 a is distributed evenly around and aligned parallel to the drum shaft 12 and perpendicular to the first drum disk 20 a and the second drum disk 20 b . A plurality of first finger modules 34 a is removably attached to each of the plurality of brackets 27 a . A second drum 18 b is formed by mounting an additional drum disk 20 c on the drum shaft 12 , then mounting a plurality of second brackets 27 b between the second drum disk 20 b and the additional drum disk 20 c . A plurality of second finger modules 34 b is removably attached to each of the plurality of second brackets 27 b . Subsequent drums 18 c , . . . , are formed in a similar manner. As shown in FIG. 5, in the Preferred Embodiment the plurality of first brackets 27 a of the first drum module 18 a is radially offset to the plurality of second brackets 27 b of the second drum 18 b , and this manner of offsetting is continued in the subsequent drums 18 c , . . . . This arrangement distributes in time the load on the drum shaft 12 , reducing maximum torsional stress and also vibrations. In the Preferred Embodiment, the diameter of the completely assembled drum array 17 is about 30 inches. Although the drum array 17 according to the Preferred Embodiment of the invention as shown in FIG. 5 a includes a plurality of drums 18 a , 18 b , 18 c , . . . , the scope of the invention is not limited to the drum array 17 . A pick-up assembly could comprise a single drum mounted on a shaft. Each of the plurality of first brackets 27 a and of the plurality of second brackets 27 b has the form of a bracket 27 , shown in FIG. 6 . According to the Preferred Embodiment, a group of nine finger modules 34 is removably attached to the bracket 27 . FIG. 6 also shows a bracket overlap 28 that extends laterally beyond the mounting width of the bracket 27 . An overlap finger module 36 is attached to this bracket overlap 28 . The purpose of the bracket overlap 28 is to allow the finger module 36 to pick up snow spillage from an adjoining drum module 18 . Another key component of the invention is the impeller assembly 5 . As shown in FIG. 7, FIG. 8, FIG. 8 a , and FIG. 9, the impeller assembly 5 of the Preferred Embodiment includes four impeller units 67 , each of the four impeller units 67 includes an impeller chamber 52 formed by an impeller wall 63 and an impeller chamber cover 59 , an impeller intake 63 formed by a divider plate 60 , an impeller exit 66 , an impeller shaft 56 , an impeller blade array 64 , and an impeller base plate 57 . As shown in FIG. 8, the impeller base plate 57 is rigidly and permanently connected to the impeller shaft 56 which is rotatably mounted on a lower support bearing 51 . The impeller blade array 64 is rigidly and permanently attached to the impeller shaft 56 and the impeller base plate 67 . In the Preferred Embodiment, the impeller blade array 64 includes six blades 58 , each of which is flat and substantially rectangular. As can be seen in FIG. 8 b , the upper blade edge 58 a is notched to improve the flow of the snow down into the impeller chamber and, also, to reduce noise. In the Preferred Embodiment, a notch 58 b has an outer leg 58 c and an inner leg 58 d , the ratio of the length of the outer leg 58 c to the length of the inner leg 58 d being 2:3. The four impeller units 67 are mounted such that an axis passing through each of the four impeller units 67 lies parallel to the discharge tube 70 and the pick-up assembly 4 . FIG. 9 shows the divider plate 60 mounted vertically between the impeller cover plate 59 of any two of the four impeller units 67 . As seen in FIG. 8 and FIG. 9, the divider plate 60 creates a separate impeller intake 63 above each impeller unit 67 and serves to reduce the amount of air crossflow across the four impeller units 67 , thereby improving the suction and reducing the amount of snow spillage. As shown in FIG. 1, snow is discharged to the right through the discharge tube end 71 . The impeller action is reversible in direction and, therefore, in other embodiments the snow can be discharged to the left or to the left and the right simultaneously, as desired. When snow is discharged to one side only, a guide plate can be installed in the discharge tube 70 at the end opposite the discharge tube end 71 or the shape of the impeller assembly/discharge tube housing 8 can be modified to prevent snow from accumulating in a comer area of the non-discharging end of the discharge tube 70 . FIG. 8 shows a Teflon disk 65 placed between the impeller assembly housing floor 8 a and the base impeller plate 57 to prevent the impeller base plate 57 from freezing to the impeller assembly housing floor 8 a . Other means for preventing ice from forming in the gap between the base plate 57 and the impeller assembly housing floor 8 a can also be used. The pick-up assembly 4 with the pick-up assembly housing 6 and the impeller-assembly/discharge-tube housing 8 including the impeller assembly 5 and the discharge tube 70 are mounted on the floating chassis 2 that is suspended from a fixed chassis 3 . In the Preferred Embodiment, the floating chassis front end 2 a is attached to the fixed chassis front end crossbar 3 a by means of a clevis pin 80 which allows the front end 2 a to pivot about the fixed chassis front end crossbar 3 a . As shown in FIG. 1 and FIG. 2, a pair of standard dolly wheels 110 , a lifting frame 112 , and a known lifting means, such as a lifting ram 111 , can be used to adjust the height of the floating chassis rear end 2 b . In the Preferred Embodiment, the dolly wheels 110 are mounted on each side of the floating chassis rear end 2 b and the lifting frame 112 is mounted in the center of the floating chassis rear end 2 b . The lifting ram 111 is mounted on a power deck 300 and attached to the lifting frame 112 . In the Preferred Embodiment, the floating chassis rear end 2 b has three operating positions: (a) In its working position, the floating chassis rear end 2 b rests on the dolly wheels 110 . The dolly wheels 110 are sized such that the tip of the middle finger 33 b of the finger module 33 just grazes the ground when the floating chassis rear end 2 b is supported by the dolly wheels 110 . As the system is operated, the dolly wheels 110 follow the contour of the ground surface, allowing the pick-up assembly 4 to follow the same contour. To adjust the working position of the floating chassis 2 , the length of the lifting ram 111 is adjusted until the dolly wheels 110 touch the ground and is then retracted approximately another inch. If the dolly wheels 110 should drop down into a recession in the ground, such as into a large pothole, the floating chassis rear end 2 b will drop down only the distance that the lifting ram 111 was retracted after adjusting the height of the floating chassis rear end 2 b because the lifting frame 112 will come to rest on the lifting ram 111 , preventing the floating chassis rear end 2 b from dropping further. This is done to protect the drum array 17 from being damaged by hitting the ground surface. (b) For an idle position, the lifting ram 111 can be extended to push up against the lifting frame 112 , raising the floating chassis rear end 2 b until the tip of the trailing finger 33 a , at its lowest position, is one to two inches above ground. (c) When the system is in transit, the lifting ram 111 can be used to raise the position of the floating chassis rear end 2 b high enough so that the lowest position of the trailing finger 33 a is six to eight inches above ground. For maintenance and repair work, the floating chassis rear end 2 b can be raised still higher by the lifting ram 111 or the fixed chassis 3 can be raised to provide easy access to the pick-up assembly 4 , the impeller assembly 5 , and the discharge tube 70 . The fixed chassis 3 can be hitched to or mounted on a prime mover which pushes or pulls the system 1 along the surface to be cleared of snow. In the Preferred Embodiment, the system 1 is hitched to a prime mover which pulls the system and powered by a commercially available hydraulic power unit that is carried external to the system on a power deck 300 shown schematically in FIG. 1 and FIG. 2 . The fixed chassis rear support 3 b is mounted on the power deck 300 . The drive motors for the drum and the impeller assembly are mounted externally on the floating chassis 2 and are shown in FIG. 1, FIG. 2, and FIG. 7 . Although the hydraulic power unit is shown carried on the power deck 300 in the Preferred Embodiment, it may be mounted externally to the snow removal system 1 in a variety of ways. Such power units and the methods of powering such equipment as that of the present invention are well-known to those skilled in the art and are not included within the scope of this invention. The belt shields 201 that cover the two hydraulic drum-shaft-drive motors 40 and the belt shields 207 that cover the two hydraulic impeller-drive motors 61 can be seen in FIGS. 1 and 2. Any commercially available hydraulic motor that provides sufficient power to drive the drum shaft, such as 20 HP hydraulic drive motors, can serve as the drive motors 40 to drive the drum shaft 12 of the pick-up assembly 4 . Commercially available motors, such as White Hydraulics RS-Series, Model 10, can serve as drive motors 61 to drive the impeller units 67 of the impeller assembly. Although this invention uses a hydraulic power system with two drive motors 40 for the drum assembly and two drive motors 61 for the impeller assembly, it is understood that it is within the scope of this invention if a different number of motors or other suitable means of driving the drum shaft and the impeller shafts are used. When the system 1 is operating in its normal mode, the drum array 17 of the pick-up assembly 4 rotates as illustrated by a directional arrow 102 in FIG. 2. A directional arrow 101 indicates the direction of travel of the system. For purposes of illustration, FIG. 7 shows the system 1 with the pick-up assembly access cover 7 , and the impeller assembly/discharge tube access cover 9 removed. The finger modules 33 on the drum array 17 pick up snow as the drum array 17 rotates around the drum shaft 12 and convey the snow to the impeller intake 63 of each of the four impeller units 67 of the impeller assembly 5 . The impeller intake 63 is an open chamber extending across all four impeller units 67 , as shown in FIG. 8 . In the Preferred Embodiment, the impeller units 67 , rotating in the direction indicated by arrow 103 , transport the snow around the impeller chamber 52 and fling the snow into the discharge tube 70 , whence it is then discharged at right angles to the direction of travel of the system 1 through a discharge tube end 71 . In the Preferred Embodiment, and as shown in FIG. 2, the discharge tube 70 is formed by the impeller assembly/discharge tube housing 8 , and the discharge tube end 71 is located at the right end of the discharge tube 70 . It is understood that the discharge tube end 71 can be located at either the left or right end of the discharge tube 70 . In the Preferred Embodiment, the plane of the impeller assembly 5 and the discharge tube 70 is tilted upward approximately 20° relative to the ground so that the plane of the impeller intakes 63 is tilted toward the pick-up assembly, as shown in FIG. 2 . It is possible to adjust the tilt of the plane of the impeller assembly 5 and discharge tube 70 to a greater angle relative to the ground. For example, a first section of the floating chassis 2 c that supports the impeller assembly 5 and the discharge tube 70 can be pivotally attached to a second section of the floating chassis 2 d that supports the pick-up assembly, as shown in FIG. 2 at 2 e . A hydraulic piston (not shown) can be mounted on each side of the floating chassis 2 on the second section of the floating chassis 2 d and attach to each side of the discharge tube 70 such that, when the piston is retracted the tilt the plane of the impeller assembly 5 and the discharge tube 70 is adjusted to a steeper tilt. FIG. 2 shows a side view of the pick-up assembly 4 and the impeller assembly 5 with the discharge tube end 71 . In the Preferred Embodiment, as shown in FIG. 2, a rear pick-up plate 11 , hingedly attached to the floating chassis 2 and extending parallel to the pick-up assembly 4 , extends below the pick-up assembly housing 6 . This rear pick-up plate 11 is flexible so that it can drag across protrusions in the ground surface. The purpose of the rear-pick-up plate 11 is to keep within the pick-up assembly area any snow that is not engaged and lifted by the pick-up assembly 4 so that the snow can be picked up during the continuing rotation of the pick-up assembly 4 . Also seen in FIG. 2 is an inclined feed plate 10 , fabricated of a rigid, smooth material such as steel, and hingedly attached to the floating chassis 2 so that it extends parallel to the axis of the pick-up assembly 4 and, as can be seen in FIG. 2, extends below the pick-up assembly housing 6 . The lower inclined feed plate edge 10 b is a distance from the ground that corresponds to the depth of snow the system 1 is designed to clear, which, in this Preferred Embodiment, is approximately four inches. Thus, the inclined feed plate 10 skims across the surface of the snow, providing a smooth, non-sticky surface against which the snow that is being lifted by the pick-up assembly 4 can slide and creep upward toward the impeller assembly 5 . The system 1 of the present invention is designed to be a versatile, multi-purpose system for removing snow and other debris from ground surfaces. To this end, the drum array 17 of the Preferred Embodiment can be easily and quickly exchanged for a drum or drum array configured for a cleaning operation other than snow removal mounted. FIG. 2 a shows a drive arrangement 200 . To exchange the drum array 17 for another drum or drum array, the belt shield 201 and the pick-up assembly housing end shield 6 a , attached to pickup assembly housing 6 at each end of the pickup assembly 4 , are removed. The belt tensioner 202 , the drive belt 204 , and the main drive pulley 203 are removed from each end of the drum array 17 , exposing each end of the inner drive shaft 12 a . Two standard, commercially available rolling carriages, each fitted with a pillow block bearing, are positioned at each end of the drive shaft 12 and adjusted in height until the rolling carriages a bearing the weight of the drum array 17 . Fasteners are removed from a drum mounting plate 205 which is arranged at each shaft end 12 a for mounting the drum array 17 on the floating chassis 1 . The rear pick-up plate 11 and the inclined feed plate 10 are loosened so as to allow the rear pick-up plate 11 and the inclined feed plate 10 to s down and free of the drum array 17 . Using the hydraulic ram 111 , the floating chassis rear end 2 b can be raised until the pick-up assembly housing 6 clears the drum array 17 . The drum array 17 can now be wheeled out from under the pickup assembly 4 . To install another drum or drum array, the process is reversed. In the Preferred Embodiment, the time estimated to exchange drums is approximately 1 hour. While a Preferred Embodiment is disclosed herein, this is not intended to be limiting. Rather, the general principles set forth herein are considered to be merely illustrative of the scope of the present invention and it is to be further understood that numerous changes may be made without straying from the scope of the present invention.

A snow removal device that picks up snow from the ground and flicks the snow into impeller units that transport the snow into a discharge tube whence the snow is expelled from the system. The system primarily includes a pick-up assembly, an impeller assembly, and a discharge tube. The pick-up assembly has a drum array that includes rows of triple-stepped blade-like fingers distributed evenly around each drum of the array of drums. These fingers are stiffly flexible and can cleanly and efficiently pick up snow from uneven ground surfaces and flick the snow into the impeller assembly that is mounted parallel to the axis of the drum array. The impeller assembly includes a plurality of impeller units that transport the snow into the discharge tube. The impeller units are reversible in direction, allowing the snow to be discharged to the right or the left of the system, or to the right and left simultaneously. The discharge tube and the impeller assembly lie in the same plane and are tilted upward approximately 20° relative to the ground. Thus, the snow is discharged at a relatively low height to the ground. The discharge tube and impeller assembly can be pivotally attached to the floating chassis, allowing the plane of the impeller assembly and the discharge tube to be tilted at a steeper angle relative to the ground. The snow removal device may be pulled or pushed by a prime mover and powered by an externally mounted hydraulic system.

BACKGROUND OF THE INVENTION This application is a continuation-in-part of my previous pending application for Log-splitting Accessory for Back Hoe Power Equipment, Ser. No. 756,951, filed Jan. 5, 1977, now U.S. Pat. No. 4,111,246. The device of this invention relates to the splitting of logs and more particularly to power-driven log-splitters. Power-driven log-splitting devices have long been in use. They fall in various categories, some of which may be characterized by devices such as described in U.S. Pat. No. 3,285,304 of O. C. Fuller which incorporates an hydraulic piston mounted on a framework adapted to force a wedge into the log to be split. U.S. Pat. No. 3,280,864 by O. C. Spanenberg discloses a similar device having an hydraulic piston forcing the log against a wedge thereby causing its splitting. U.S. Pat. No. 3,779,295 by Balsbaugh discloses a device utilizing an hydraulic piston forcing a wedge into the log to be split wherein the operative mechanism is tiltable on a frame so that one may not necessarily have to lift the log up into the mechanism, but can merely stand the log on the base for splitting. There are several devices such as characterized in U.S. Pat. No. 3,319,675 to M. J. Bles, Sr.; U.S. Pat. No. 3,356,115 to H. J. Cole; U.S. Pat. No. 3,760,854 to Worthington; and U.S. Pat. No. 3,938,567 to Dickerson, all of which are accessories to tractor units containing various embodiments of mechanisms for the splitting of logs and which usually fit as accessories toward the rear of the tractor. A device which fits at the front of a tractor in lieu of a front end loader bucket is disclosed in U.S. Pat. No. 3,780,779 to Guy. Disclosed is an hydraulic piston forcing the log into a wedge at the base of an arm member. A wood-splitting attachment for a back hoe is disclosed in U.S. Pat. No. 4,019,549 to Williams. SUMMARY It is an object of this invention to provide a power log-splitter which is utilized as an accessory to power equipment having a back hoe arm. The apparatus of this invention contains no hydraulic parts in its construction and can be attached directly to a back hoe to function utilizing the back hoe's boom and stick in their regular mode of operation including the utilization of the hydraulics of the back hoe's boom and stick. The body of the present invention is affixed to the stick member of the back hoe, and the wedge of the present invention is connected to the hydraulic piston rod, positioned substantially parallel to the boom's stick. The wedge moves upward or downward according to the movement of the piston rod which is actuated hydraulically through the hydraulic tubes interconnected to control levers on the back hoe's body. As the wedge moves upward or downward, its movement is channeled within rail members. Logs to be split are placed on the base of the frame in vertical alignment with the wedge which is then forced downward into the log to split same. The apparatus of this invention functions with superior power and ease in splitting logs and can be economically manufactured. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a side view of the device of this invention in use with a back hoe. FIG. 2 illustates a side view of the device of this invention with wedge member removed. FIG. 3 illustrates a front view of the device of this invention. FIG. 4 illustrates a top view of the device of this invention with wedge in place. FIG. 5 illustrates side and front views of the wedge member. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates the device of this invention in use attached to a back hoe stick 30 shown in outline form along with back hoe 20 and boom 21. FIG. 2 is an enlarged view of the device of this invention showing back hoe stick 30 inserted into the device of this invention and affixed thereto by pin 32 extending through the lower aperture 5 in the base of stick 30 and into horizontally corresponding apertures 12 in upright members 2. The aperture usually located above lower aperture 5 on stick 30 seen in outline form is not utilized in this invention. The device's two upright members 2 are spaced apart from one another a distance sufficient to insert stick 30 therebetween although a somewhat wider spacing can be utilized. These upright members 2 are affixed to base 1 and can be reinforced for additional strength such as by gusset members 16 and 17. Extending from base 1 upwards and running between the two upright members 2 is curved plate 31. This plate is also seen in FIG. 4 wherein its inward concavity is more clearly illustrated. Curved plate 31 prevents logs from being forced between upright members 2 as they are being split thereby keeping them on the working area of base 1. At the top rear of upright members 2 and extending therebetween and affixed thereto is brace beam 4. Extending behind upright members 2 from brace beam 4 to base 1 is strong bar 11 which can be an I-beam centrally disposed between and to the rear of upright members 2. Strong bar 11 acts as a stabilizing means. A strong bar brace member 3 which extends between upright members 2 and is affixed thereto can be affixed to strong bar 11 by bolts directly to the inner portions of the I-beam of strong bar 11 or by equivalent means of affixation. One other method of affixation illustrated herein can be by bolts extending on either side of strong bar 11 from strong bar brace 3 through strong bar rear support member 26 which extends across the rear of strong bar 11 and is affixed by nuts to the bolts, thereby attaching the strong bar firmly in position. Wedge assembly support plate 40 is affixed to the front upper portion of upright members 2 and extends completely thereacross. To this wedge assembly support plate 40 is affixed wedge carrier assembly 42 which consists of two rail support members 6 affixed to the wedge assembly support plate 40 by welding or equivalent means and have disposed on their inner sides wedge rails 7 adapted so that the wedge assembly can slide up and down therebetween. Brace beam 4, wedge assembly support plate 40, and strong bar 11 all interact to prevent angular movement of stick member 30 by enclosing it in a structure in which it can have no angular movement in relation to the device of this invention. Further rail support members 6 and associated wedge rails 7 allow the wedge assembly to be maneuvered in parallel relation only to upright members 2 when it is attached to and moved by the piston rod and forced into a log positioned vertically on base 1 of the device of this invention. It has been found helpful to utilize a collar member 18 to hold the piston member 19 and the stick in permanent alignment to one another so that they will not move apart during the operation of the device of this invention. Collar member 18 also seen in FIG. 1 consists of plates and bolt members or any equivalent thereto to prevent the piston and stick 30 from spreading apart. Rail support members 6 can extend somewhat forward of wedge rails 7 and can have one or more rail support front bars 23 extending horizontally across the front thereof joining the two members for additional strength. FIG. 1 also illustrates control rod 38 used with the device of this invention. Attached at one end to the hydraulic control activating the upward and downward movement of the piston member rod 13 and wedge affixed thereto, control rod 38 runs through retaining hook member 41 positioned upon the body of the log-splitting device which positioning prevents it from falling to the ground and also allows the operator of the device to position a log upon the device and activate the log-splitting mechanism without having to walk back to the back hoe controls. The operator merely manipulates control rod 38 from a position where he can, if he desires, support the log initially until the wedge is engaged with the log. Once the wedge is engaged with the log, the splitting process proceeds smoothly. The operator can cause the wedge to lift by maneuvering the control rod 38 from his position near the log-splitting activity. FIG. 3 illustrates a front view of the device showing curved plate 31 and wedge assembly support plate 40 in position and strong bar 11 centrally located behind upright members 2 extending up to brace beam 4. FIG. 4 shows a top view of the device of this invention with wedge in position illustrating strong bar 11 and brace beam 4 and also the relationship of wedge carrier assembly 42 and wedge member 52 in position to slide up and down within wedge rails 7 on the inside of rail support members 6. Also seen is rail support front bar 23 extending across the front between the rail supports. FIG. 5 illustrates front and side views of the wedge showing the wedge slide members 44 which travel within wedge rails 7. Wedge slide members 44 are affixed to wedge support members 46 which have defined therein aperture 48 for interconnection with the rod 13 of piston member 19 by insertion of a pin through aperture 48 and through the aperture 50 at the end of piston rod member 13 when disposed therebetween. Wedge member 52 is affixed to wedge support members 46. The device of this invention can be completely fabricated of welded steel parts or equivalent strong metal. Although the present invention has been described with reference to particular embodiments, it will be apparent to those skilled in the art that variations and modifications can be substituted therefor without departing from the principles and spirit of the invention.

Power log-splitting apparatus utilized as an accessory to back hoe-equipped power equipment comprising a base, an upright member affixed to the base with means for affixing the upright member to the stick member of the back hoe with a wedge member affixed to the piston of the back hoe. Rail means are provided within which the wedge member is guided into a log to be split, and stabilizing means, affixed to the upright member, is adapted to prevent tilting of the base while the log splitter is in use.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. §119(e) upon U.S. Provisional Patent Application No. 62/039,539, entitled “CATHETERS HAVING AN ANTIMICROBIAL TREATMENT” filed on Aug. 20, 2014, by Patrick E. Eddy. This application is a continuation-in-part of U.S. patent application Ser. No. 14/216,020, entitled “INTRAVENOUS CONNECTOR HAVING ANTIMICROBIAL TREATMENT” filed on Mar. 17, 2014, by Patrick E. Eddy, now U.S. Pat. No. 9,433,708, which claims priority to U.S. Provisional Patent Application No. 61/786,930, entitled “INTRAVENOUS CONNECTOR HAVING ANTIMICROBIAL TREATMENT” filed on Mar. 15, 2013, by Patrick E. Eddy. The entire disclosures of each of the above applications are incorporated herein by reference. BACKGROUND OF THE INVENTION The present invention generally relates to vascular access products such as intravenous (IV) administration tubing, catheters and the associated caps, luers, Y sites, connectors, drip chambers, peripherally inserted central catheter (PICC) lines, stopcocks and similar IV components. Vascular access products such as IV administration tubing, catheters and the associated caps, luers, Y sites, connectors, drip chambers, PICC lines, stopcocks and similar IV components such as needleless IV connectors having valve mechanisms are known in the art. Examples of such vascular access products are available from Health Line Medical Products of Centerville, Utah, and are visible on their website at www.hlic.net. An example of a valve mechanism for a needleless IV connector is the medical valve described in U.S. Pat. No. 5,685,866 assigned to ICU Medical, Inc. who also makes such needleless IV connectors under the trademark MicroClave®. One of the MicroClave® needleless IV connectors is available with an antimicrobial treatment, where the antimicrobial treatment consists of ionic silver. Such ionic silver, however, is subject to leaching over time. SUMMARY OF THE INVENTION According to an embodiment of the present invention, a vascular access product is provided comprising a component having a plurality of external surfaces, wherein at least one of said surfaces is coated with an antimicrobial treatment, wherein said antimicrobial material comprises a silane quaternary ammonium salt. According to another embodiment of the present invention, a catheter is provided comprising a component having a plurality of external surfaces, wherein at least one of said surfaces is coated with an antimicrobial treatment, wherein said antimicrobial material comprises a silane quaternary ammonium salt. In one or more of these embodiments, the silane quaternary ammonium salt may comprise 3-(trimethoxysilyl) propyldimethyloctadecyl ammonium chloride. These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIGS. 1A and 1B show acute hemo-dialysis catheters according to one embodiment; FIG. 1C shows a PICC line according to another embodiment; FIG. 1D shows a peritoneal dialysis catheter according to another embodiment; FIGS. 1E and 1F show chronic hemo-dialysis catheters according to another embodiment; FIG. 2 is a schematic representation of a monomer that may be used in the embodiments described herein as an antimicrobial treatment substance; FIG. 3 is a schematic representation of a plurality of the monomers shown in FIG. 2 as applied to a treated surface; FIG. 4A is a schematic representation of the monomer shown in FIGS. 2 and 3 illustrating a first step in the manner by which the monomer destroys a microbe; FIG. 4B is a schematic representation of the monomer shown in FIGS. 2 and 3 illustrating a second step in the manner by which the monomer destroys a microbe; and FIG. 4C is a schematic representation of the monomer shown in FIGS. 2 and 3 illustrating a third step in the manner by which the monomer destroys a microbe. DETAILED DESCRIPTION OF THE EMBODIMENTS Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. In the drawings, the depicted structural elements are not to scale and certain components are enlarged relative to the other components for purposes of emphasis and understanding. As noted above, the embodiments described herein pertain to vascular access products such as catheters. Because such vascular access products may provide a path into the patient's bloodstream, it is important that they do not harbor bacteria or other microbes. Novel vascular access products are disclosed herein that not only provide the requisite properties for such vascular access products, but also eliminate bacteria on contact. As discussed below, the components of the vascular access products are either treated with or formed with an antimicrobial substance comprising a silane quaternary ammonium salt. Examples of vascular access products that may be so treated are shown in FIGS. 1A-1D . FIGS. 1A and 1B show an example of a first embodiment wherein acute hemo-dialysis catheters 10 a and 10 b have one or more of their external surfaces 50 coated with an antimicrobial treatment. FIG. 1C shows an example of a second embodiment wherein a PICC line 20 has one or more of its external surfaces 50 coated with an antimicrobial treatment. FIG. 1D shows an example of a third embodiment wherein a peritoneal dialysis catheter 30 has one or more of its external surfaces 50 coated with an antimicrobial treatment. FIGS. 1E and 1F show an example of a fourth embodiment wherein chronic hemo-dialysis catheters 40 a and 40 b have one or more of their external surfaces 50 coated with an antimicrobial treatment. In general, the antimicrobial treatment may be applied to all surfaces 50 of the above vascular access products ( 10 a , 10 b , 20 , 30 , 40 a , 40 b ). However, it is possible to obtain benefits by treating at least one of the surfaces treated with the antimicrobial treatment, and particularly the surfaces contacting the patient. The surfaces 50 of the vascular access products are coated with an antimicrobial treatment that may be sprayed onto the surfaces using a solution and/or may be applied using wipes soaked in such a solution. Suitable wipes and solutions are disclosed in commonly assigned U.S. Pat. No. 8,491,922, the entire disclosure of which is incorporated herein by reference. In this case, the antimicrobial material is again one of the silane quaternary ammonium salts described above. In a preferred form, the antimicrobial treatment solution contains 30-50 percent by volume isopropyl alcohol and 50-70 percent by volume antimicrobial treatment substance, which is preferably a silane quaternary ammonium salt having an unreacted organofunctional silane. If the antimicrobial treatment solution is applied by spraying or dipping, the solution most preferably includes 50 percent by volume isopropyl alcohol and 50 percent by volume of the unreacted antimicrobial treatment substance. If the solution is applied using the wipes, the solution is preferably 30 percent by volume isopropyl alcohol and 70 percent by volume of the unreacted antimicrobial treatment substance. The isopropyl alcohol may have a concentration of 70-90 percent by volume. By providing the unreacted organofunctional silane in isopropyl alcohol, the organofunctional silane does not react with the wipe substrates or the inside of the wipe container such that it is free to later react and permanently covalently bond with the inner and outer surfaces 50 of the vascular access products. Isopropyl alcohol is preferred as it evaporates quickly once the solution is wiped onto the treated surface to allow the unreacted organofunctional silane to more quickly react with the treated surface. The preferred organofunctional silane quaternary ammonium salt also prevents odor, staining and product deterioration that may be associated with microbe contamination. The preferred organofunctional silane quaternary ammonium salt is also beneficial because it permanently bonds to a treated surface, covers a broad spectrum of activity with no negative effects or drawbacks, and is easily incorporated and easily verifiable. The preferred organofunctional silane quaternary ammonium salt is designed to react and create a covalent bond with the surfaces of the plastic components. The reacted substance is held onto those surfaces until the covalent bond is broken. Tests have shown that most industrial cleaners or disinfectants will not remove the preferred antimicrobial treatment substance. The method of removal is by abrasion. The preferred silane quaternary ammonium salt includes an active ingredient of 3-(trimethoxysilyl) propyldimethyloctadecyl ammonium chloride and other inert ingredients. The silane quaternary ammonium salt preferably includes about 0.1 to 50 percent by weight of the 3-(trimethoxysilyl) propyldimethyloctadecyl ammonium chloride and most preferably includes about 5 percent by weight of the 3-(trimethoxysilyl) propyldimethyloctadecyl ammonium chloride. Such silane quaternary ammonium salts are available from Aegis Environments of Midland, Mich., which is identified as “AEM 5772-5 Antimicrobial,” and from Piedmont Chemical Industries I, LLC of High Point, N.C., which is identified as “PROMOFRESH X 105.” The antimicrobial treatment solution with the isopropyl alcohol is available from MicrobeCare, LLC of Allendale, Mich., under the trademark MICROBECARE™. The above described silane quaternary ammonium salt is preferred because it is an organofunctional silane antimicrobial treatment substance that is substantially free from arsenic, silver, tin, heavy metals and polychlorinated phenols; copper; or a silver-ion emitter. In addition, it not only eliminates bacteria on contact, but it remains on the treated surfaces 50 and kills any bacteria subsequently contacting these surfaces. Such treatment preferably lasts at least one week, more preferably several months, and most preferably indefinitely. FIG. 2 shows a schematic representation of a monomer form 130 of a preferred organofunctional silane serving as the antimicrobial treatment substance. As illustrated, monomer 130 includes a silane base 131 for bonding to a surface 50 , a positively charged nitrogen molecule 134 , and a long molecular chain 132 . As shown in FIG. 3 , the silane bases of these monomers covalently and permanently bond to each other and to the surface 50 to be treated in such a way that the long molecular chains are aligned and pointing outward from the surface 50 . This tight bonding provides a micropolymer network that serves as a protective coating on the outside of the surface 50 that destroys any microbes that come into contact. The manner by which the preferred organofunctional silane destroys microbes is illustrated in FIGS. 4A-4C . Such microbes may include bacteria, mold, mildew, algae, etc. As shown in FIG. 4A , the cell membrane 120 of the microbe is attracted to the treated surface 50 of the vascular access product and then is punctured by the long molecular chain 132 of the monomer 130 . As the microbe is drawn closer because of the positive-negative ion exchange, the monomer 130 penetrates further into the cell membrane 120 as shown in FIG. 4B . Once the cell membrane 120 is penetrated deeply, it is physically ruptured by a sword-like action and then electrocuted by a positively charged nitrogen molecule 134 of the monomer 130 , thus destroying the microbe as illustrated in FIG. 4C . Thus, the microbes are eliminated without “using up” any of the antimicrobial active ingredients, which remain on the surfaces 50 ready to continue protecting the treated item against further microbial contamination. The preferred organofunctional silane is designed to react and create a covalent bond with the surfaces 50 of the vascular access product. The reacted substance is held onto those surfaces 50 until the covalent bond is broken. Tests have shown that most industrial cleaners or disinfectants will not remove the preferred antimicrobial treatment substance. The method of removal is by abrasion. In the event that the vascular access product or at least a part of the vascular access product is made of silicone, the antimicrobial material may be integrally formed within the silicone. In general, silicones are formed of slurries processed at relatively low temperatures. These low temperatures allow the antimicrobial material to be mixed in with the slurry and therefore integrated within the resulting foam or silicone part. The percentage of antimicrobial material in the slurry may vary from 0.001% to 20% by weight. Although the invention is described with respect to particular constructions of the vascular access products shown in FIGS. 1A-1D , the constructions thereof may vary. Also, the present invention may be applied to arterial connectors and IV connectors. The above description is considered that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the claims as interpreted according to the principles of patent law, including the doctrine of equivalents.

A vascular access product is provided having a component with a plurality of external surfaces. At least one of the surfaces is coated with an antimicrobial treatment, wherein the antimicrobial material comprises a silane quaternary ammonium salt. The silane quaternary ammonium salt may comprise 3-(trimethoxysilyl) propyldimethyloctadecyl ammonium chloride. The vascular access product may be IV administration tubing, a catheter and the associated caps, luers, Y sites, connectors, drip chambers, PICC lines, stopcocks and similar IV components such as needleless IV connectors having valve mechanisms.

The government has rights in this invention pursuant to Contract No. N00123-77-C-1045 awarded by the Department of the Navy. BACKGROUND OF THE INVENTION This invention relates generally to operational amplifiers, and, more specifically, to operational amplifiers having not only a very high gain, but also a very broad bandwidth. The term operational amplifier was originally introduced by workers in the analog computer field to denote an amplifier circuit for performing various mathematical operations, such as integration, differentiation, summation and subtraction. In these circuits, the required response is obtained by the application of negative feedback to a high gain direct current (dc) amplifier, by means of components connected between amplifier input and output terminals in a manner referred to as "operational feedback." The term operational amplifier is now more generally used to designate any high performance amplifier suitable for use with this type of feedback. Operational amplifiers are used not only in analog computation systems, but also in a wide range of other applications in such fields as instrumentation and control system engineering. On a theoretical level, an ideal operational amplifier has the characteristics of infinite gain between the input and output terminals; infinite input impedance, so that no current flows into the input terminals; zero output impedance, so that the amplifier is unaffected by changes in electrical load coupled to the output terminals, and an infinite bandwidth, i.e. a bandwidth extending from zero to infinity to insure both a response to dc signals and an instantaneous response to change all types of input signal. Another characteristic of the ideal amplifier is that the output voltage signal will be zero when the input signal is zero, regardless of the nature of the input source. This charcteristic is called a zero offset. In a practical operational amplifier, neither the amplifier gain nor the bandwidth is infinite. One measure of the performance of a practical amplifier is the product of the gain and the bandwidth, which is usually expressed as the frequency at which the gain falls to a value of unity. The best operational amplifiers prior to this invention have unity gain frequencies typically of around one megahertz (MHz), with a few devices providing a unity gain frequency as high as 200 MHz. There is need in some application areas, however, for an amplifier with a unity gain frequency in the range 800 MHz to 1.5 gigahertz (GHz). The only practical way to provide a very high gain in an amplifier employing bipolar transistors is to provide a large load resistance in the collector circuit of at least one stage of the amplifier. However, simply providing a passive resistance of some hundreds of thousands of ohms in the collector circuit results in unacceptably large voltage drops, and is therefore impractical. The solution employed in operational amplifiers of the prior art is to include an active current source, rather than a passive resistance in the collector circuit. The active current source provides a practically infinite resistance but still conducts a finite current and requires only a small voltage to sustain it. In operational amplifiers, the only practical way of providing such an active current source is by means of a PNP transistor. All operational amplifiers of the prior art have followed this approach, which has two significant drawbacks. First, in many processes used for the fabrication of monolithic operational amplifiers, i.e. amplifiers formed as a single integrated circuit, it is extremely difficult to control the characteristics of both PNP and NPN transistors simultaneously in the same process. Typically, the NPN devices yield the desired characteristics of high gain and bandwidth, but the PNP transistors tend to have only a moderate gain and an unacceptably low bandwidth. Consequently, the composite amplifier has only moderately good performance characteristics. Secondly, regardless of the fabrication process used, even the most successful operational amplifiers employing PNP transistors to provide a large collector resistance have only moderately high frequency at unity gain, typically in the range of one to two MHz. It will be appreciated from the foregoing that there is a significant need in the operational amplifier field for an amplifier capable of providing unity gain frequency in excess of one GHz. The present invention fulfills this need. SUMMARY OF THE INVENTION The present invention resides in an operational amplifier comprised of only NPN transistors and employing a novel negative resistance cell to provide a high gain and an extremely wide bandwidth. More specifically, the amplifier of the invention includes a two-stage differential pair amplifier, of which the second stage is emitter degenerated in an active negative resistance. The novelty of the invention may be alternatively defined in terms of the radically different approach that is taken for maximizing gain. Reduced to its simplest terms, the gain of an operational amplifier stage may be expressed mathematically as the quotient obtained by dividing a numerator expression by a denominator expression. The numerator expression is dominated by the collector resistance term, and previous efforts to maximize gain have always focused on the maximization of this term. In the amplifier of the present invention, however, the denominator of the gain expression, which includes the sum of a number of resistance terms, is minimized by making one of the resistance terms negative, and hence the denominator itself as close as possible to zero. Since the denominator of the gain expression is minimized, the gain itself is maximized. Moreover, the device has an extremely wide bandwidth, and a unity gain frequency in excess of one gigahertz. Briefly, and in general terms, the basic gain cell of the invention includes a first pair of NPN transistors connected as a differential amplifier pair and having an input signal applied across the bases of the transistors, and a second differential pair of NPN transistors having an input signal applied across its bases and derived from the collectors of the first differential pair, and having its output signal taken in cascode from the collectors of the second differential pair. The emitters of the first differential pair of transistors are tied together directly, as is conventional, but in accordance with the invention the emitters of the second stage differential pair are connected to an active negative resistance circuit. In accordance with an important aspect of the invention, the active negtive resistance circuit is provided by a simple cross-connection of two additional matched NPN transistors. The collectors of these transistors are connected to respective emitters of the second-stage differential pair of transistors, and the emitters of the negative resistance transistor pair are coupled together to a common current source. The bases of the two matched transistors are cross-coupled to the collectors. As viewed from the emitters of the second differential pair of transistors, the impedance of the negative resistance circuit is determined in part by the negative of the internal emitter resistance of the transistors making up the circuit. Since the emitter resistance is accurately controllable during fabrication of the device, the negative resistance circuit of the invention provides an extremely stable resistance unaffected by variations in either frequency or voltage level. Consequently, the resulting gain of the basic gain cell is very high over a wide range of frequencies and voltage conditions. A complete operational amplifier in accordance with the invention utilizes one or more of the basic gain cells employing the negative resistance circuit as described. The basic gain cell has a minor disadvantage in that it has a characteristically high output resistance. However, this factor can be taken care of by means of a conventional impedance buffer to transform the high impedance of the circuit to a desirably low output impedance. Subsequently, conventional operational amplifier stages may be used to provide additional amplification, or additional basic gain cells employing negative resistance circuits could be employed. It will be appreciated from the foregoing that the present invention represents a significant advance in the field of operational amplifiers. In particular, it provides an operational amplifier having extremely high bandwidth as well as large gain. Other aspects and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified schematic view of a basic gain cell employed in the present invention. FIG. 2 is a typical interconnection diagram showing how an operational amplifier is connected at its inputs and outputs; and FIG. 3 is a detailed schematic diagram of the operational amplifier of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings for purposes of illustration, the present invention is concerned with an improved operational amplifier providing an extremely high gain-bandwidth product. An operational amplifier is basically a three-terminal device used in a variety of analog computation and control system circuit, principally as a direct-current (dc) amplifier of ideally infinite gain, and usually in conjunction with a negative feedback circuit. In many applications, it is also desirable to maximize not only the gain but also the bandwidth of the device. An ideal operational amplifier is responsive over a frequency range from zero to infinity, but of course, the ideal is never achieved in practice. In prior operational amplifiers, gain is maximized by providing an extremely high collector resistance, usually in the form of an active current source. Amplifiers of this type employ PNP transistors as an active current source, and typically have only moderately high gain-bandwidth products. The gain-bandwidth product is usually expressed in terms of the frequency at which the amplifier gain falls to unity, or the "unit gain frequency." Amplifiers of the prior art have unity gain frequencies in the region of 1 megahertz (MHz), with a few devices providing a unity gain frequency up to 200 MHz. In accordance with the present invention, an operational amplifier of very much higher unity gain frequency is provided, not by maximizing the collector resistance, but instead by emitter-degenerating a differential stage of the amplifier through an active negative resistance circuit. The resulting amplifier has a unity gain frequency in excess of one gigahertz (GHz), and possible as high as 1.5 GHz. An operational amplifier usually has more than one amplifier stage or cell. The novelty of the present invention lies principally in the organization of a single gain cell, which may be used just once in conjunction with conventional gain stages, or may be used more than once in a single operational amplifier. The novel gain cell of the invention is referred to in this specification as the basic gain cell, and it is illustrated in FIG. 1. As shown in FIG. 1, the basic cell comprising a first differential pair of NPN transistors, indicated by reference numerals 10 and 12, respectively, and a second differential pair of NPN transistors 14 and 16. The emitters of the second differential pair 14 and 16 are coupled to a negative resistance circuit made up of two additional NPN transistors 18 and 20. Yet another pair of NPN transistors 22 and 24 provide a conventional cascode common-base stage, to provide additional bandwidth compensation. The specific details of device interconnection in the basic cell are as follows. The emitters of the first differential pair 10 and 12 are connected together to a current generator 26, and the emitters of the negative resistance pair 18 and 20 are connected to another current generator 28. The input terminals of the basic cell are the bases of the first differential pair 10 and 12. The input signals are shown diagrammatically in FIG. 1 as three voltage generators 30-32. Generators 30 and 31, each of half the input signal, are connected in series between the bases of transistors 10 and 12, and generator 32 is connected between ground and the junction between generators 30 and 31. Generator 31 represents a "common-mode" signal, i.e. a signal applied with the same polarity to both input terminals. The collectors of the first differential pair of transistors 10 and 12 are connected to the bases of the second differential pair 14 and 16, respectively, and also, through diodes 34 and 36, respectfully, to the bases of transistors 22 and 24, the anodes of the diodes being connected to the bases of transistors 22 and 24. The collectors of transistors 22 and 24 are connected to a power supply line 38 through collector resistances 40 and 42, respectively. The power supply line 38 is also connected to the bases of transistors 22 and 24, through a variable resistor 44. It is important to note that the emitters of the second differential pair of transistors 14 and 16 are not tied directly together, but are coupled to the respective collectors of transistors 18 and 20 in the negative resistance circuit. In addition, the bases of transistors 18 and 20 are cross-coupled to their collectors, i.e. the base of transistor 18 is connected to the collector of transistor 20 and the base of transistor 20 is connected to the collector of transistor 18. This cross-coupled pair of transistors constitutes a very stable negative resistance circuit. To appreciate the important contribution that this arrangement makes to the characteristics of the amplifier, it is necessary to consider the mathematical expression for the gain of the amplifier. The differential mode gain of the basic amplifier cell may be derived using conventional equivalent circuit theory to yield the following expression: ##EQU1## The equivalent resistance of the negative resistance circuit is given by the expression: ##EQU2## where the symbols have the same meanings as above. It will be seen from the gain expression set forth above that the gain may be maximized by making the collector resistance as large as possible. This has been the traditional approach of the prior art. The novel approach of the present invention, however, is to minimize the denominator in the right-hand factor of the gain expression. Since this denominator is the sum of three fixed resistance parameters and an expression involving the equivalent negative resistance of the transistor pair 18 and 20, the denominator can be made to approach zero by an appropriate choice of negative resistance. Moreover, since the negative resistance is determined by accurately controllable transistor characteristics, primarily the internal emitter resistance, the negative resistance value can be determined in advance to a high degree of precision. An added benefit is that the value of the negative resistance is, for all practical purposes, independent of variations in frequency and voltage, and is also relatively insensitive to temperature variations. Before considering how the basic cell of the invention may be employed in a complete operational amplifier, it will be useful to first review a typical external interconnection diagram for an amplifier of this type. As shown in FIG. 2, an operational amplifier, indicated by the triangle 50, has an inverting input terminal 42, a non-inverting input terminal 54, and an output terminal 56. It will be understood that some operational amplifiers have differential outputs as well as differential inputs, and the illustration of a single-ended output device is not intended to be a limitation of the invention. The amplifier 50 also has a ground terminal 58, an ac ground terminal 60 coupled to ground through a capacitor 62, and two current compensation terminals 64 and 66. The input signal is shown as a source generator 68 with a source resistance 70, the generator being connected through the source resistance between the non-inverting input terminal 54 and the ac ground 60. A resistor 72 connected between the inverting input terminal 42 and the ac ground 60 should have a resistance value nominally equal to the Thevenin equivalent circuit source resistance seen by the driven input terminal. Variable resistors 74 and 76 are connected between ground and the respective current compensation terminals 64 and 66, to provide an adjustment for maximum gain and for zero low frequency phase angle between output and input signals. Frequency compensation by means of externally connected capacitors is common in operational amplifiers, but is not shown in FIG. 2 because the specific design of the amplifier contemplates that the capacitors are provided on the same circuit chip as the amplifier circuitry. Optional bonding connections may then be made to the selected capacitors, none of which are shown. A presently preferred embodiment of the invention is shown in the detailed schematic diagram of FIG. 3. Since most of this circuitry is conventional, it will not be described in detail. However, it will be useful to point out the basic amplifier cell in FIG. 3, and to indicate generally the functions of the other circuit modules of the amplifier. The first differential transistor pair of the basic amplifier cell comprises transistors Q20 and Q21, these being equivalent to transistors 10 and 12, respectively, in FIG. 1. The second differential transistor pair comprises four transistors Q12-Q15. It will be observed that these transistors are connected in parallel pairs, to equalize current distribution and hence to preclude excessive thermal gradients within the cell. Thus, transistor 14 in FIG. 1 is equivalent to transistors Q12 and Q13 in FIG. 3, and transistor 16 is equivalent to transistors Q14 and Q15. Similarly, the negative resistance circuit comprising transistors 18 and 20 in FIG. 1 is equivalent to transistors Q16-Q17 and Q18-A19, respectively. The cascode stage of the basic cell, indicated by reference numerals 22 and 24 in FIG. 1, are the transistors Q8-Q11 in FIG. 3. Transistors Q6 and Q7 are connected as diodes and are equivalent to the diodes 34 and 36 in FIG. 1. Transistor Q22 is current sink performing the function of current generator 28 in FIG. 1, and transistors Q3-Q5 together comprise a frequency compensated current sink equivalent to the generator 26 in FIG. 1. The ratio of the currents in transistors Q22 and Q5 controls the negative resistance of the basic cell, and hence the gain and low frequency characteristics of the operational amplifier. In the circuit shown, transistor Q22 conducts a current of 1.6 milliampere (mA), and transistor Q5 conducts 0.570 mA under balanced conditions. External taps 64 and 66 are provided at the emitters of transistors Q4 and Q22 for fine adjustment of this current ratio. The current sources are thermally compensated by a stabilized reference source comprising transistors Q1 and Q2. The circuitry including transistors Q23-Q26 is an impedance buffer to transform the output impedance of the basic cell to an acceptable value. The impedance buffer circuitry drives a differential level shifter comprising transistors Q27-Q30. Transistor Q31 provides an emitter follower output voltage extracted from a double-to-single ended converter defined by transistors Q35 and Q36. Transistor Q32 precludes an excessive imbalance on both sides of the level shifter, and transistors Q37 and Q38 supply a stabilized bias for the emitter follower output. Frequency compensation is implementated by connecting a capacitor between the terminals labeled COMP A1 and COMP A2, and another between the terminals COMP B1 and COMP B2. As mentioned earlier, these capacitors are made available for bonding on the amplifier chip, but of course this has nothing to do with the inventive aspects of the amplifier. The following are the resistance values in ohms employed in the illustrative circuit of FIG. 3: ______________________________________ R1 800 R2 3.85k R3 715 R4 1.47k R5 1.58k R6 845 R7 390 R8 2.29k R9, R10 2k R11 610 R12, R13 530 R14, R24 655 R15, R16 180 R17, R18 1.26k R21, R22 1.56k R19, R20 890 R29 400 R23 1.3k R25 1.05k R26 1.6k R27 780 R28 2.1k______________________________________ The illustrative amplifier has an open-loop gain of approximately 75dB, and a unity gain frequency of approximately 1.25 GHz. Other characteristics are an input bias current of 1 microampere of less, an input resistance of 200,000 ohms or greater, a common mode rejection ratio of 65dB or greater, an output resistance of 100 ohms or less, and a power dissipation of approximately 265 mW at 12 volts. It will be appreciated from the foregoing that the present invention represents a significant improvement in the field of operational amplifiers. In particularly, the invention provides an amplifier with a unity gain frequency about five to ten times greater than that of previously available operational amplifiers. It will also be appreciated that, although one embodiment of the invention has been described in detail for purposes of illustration, various modifications to the described circuitry may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.

An operational amplifier having an extremely high gain-bandwidth product. The amplifier includes a gain cell with an active negative resistance circuit made up of two matched NPN transistors (18 and 20) with their bases cross-connected to their collectors, and with a differential pair of NPN transistors (14 and 16) having their emitters degenerated through the active negative resistance circuit. The value of the negative resistance is chosen to negate other resistance values in the denominator of a fraction expressing overall amplifier gain, which is therefore maximized. Since no PNP transistors are needed to maximize gain in the amplifier, NPN transistors can be used exclusively, and the amplifier can be more conveniently fabricated in integrated-circuit form, with a desirably wide bandwidth.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Patent Application No. 62/144,657 that was filed on Apr. 8, 2015. FIELD OF INVENTION [0002] The present invention relates to a device that may apply a vectored force radially outward from a central axis. Such vectored force may be applied in multiple directions at once where the application of the vectored force is to maintain the central axis of the device relatively aligned with the central axis of the tubular through which the device passes. BACKGROUND [0003] Once a hydrocarbon bearing well has been drilled it is usually necessary to perform several tests upon the well, for instance to determine the integrity of the casing after it has been installed, to determine for instance the quality of the cementing job, or to determine the presence and locations of any hydrocarbons adjacent to the well. Such testing is usually done with a set of instruments referred to as a logging tool. In most instances the logging tool is lowered into the well on a cable, where the cable may include a power and/or data line. Logging tools may be transported through any tubular structure including pipelines and refineries. [0004] Certain types of logging tools work best when they are centrally positioned within the tubular structure being tested. In order to centrally position the logging tool within the tubular, a centralizer may be used. Centralizers typically use a set of springs, such as bow springs, to apply force radially outward from a central axis. Provided that the force is applied equally in all directions and that there is sufficient force to overcome any bias due to the weight of the logging tool, the logging tool will remain more or less centralized within the wellbore, whether open hole or cased hole. Unfortunately the diameter of the wellbore varies as the tool progresses through the wellbore. Variations in diameter may be due to other tools or equipment located in the wellbore or to different sizes of casing installed as the well progresses from the surface to the well's final depth. Other variations in the well diameter may be due to changes in the well's direction causing the casing to become ovalized as the tubular bends through turns. Unfortunately the force applied to different sizes of tubulars by a standard centralizer varies such that a centralizer may have sufficient force to keep a logging tool centralized in one size of tubular, but when the logging tool is in a smaller diameter tubular such force is excessive, causing damage to the centralizer or even preventing the centralizer from progressing through the well. On the other hand while the force applied may be sufficient to keep a logging tool centralized in one size of tubular, in a larger diameter tubular such force is inadequate allowing the logging tool to substantially deviate from the center of the tubular. [0005] In order to address such concerns many variations of constant force centralizers have been developed. There are several constant force centralizers available in the market, but there is very little information showing quantitative force values vs. casing size. Ideally, each constant force centralizer would have a force chart similar to the force chart shown in FIG. 1 . [0006] Though customers seem to have a clear need for a constant force centralizer, such requests do not appear to include a definition of “constant.” The understanding is that clients just need a device that keeps their tools centralized in a wide range of environments. SUMMARY [0007] A constant force centralizer is envisioned where a first non-constant axial force drives the first set of arm assemblies and at least a second non-constant axial force drives the second set arm assemblies where the two sets of arm assemblies are offset from one another by 90°. Typically the non-constant axial forces are provided by some type of biasing device usually a spring or compressed gas but other types of biasing devices may be used. A force guide may be permanently affixed, rotatably attached, or otherwise mounted on the central mandrel of the constant force centralizer. Each of the non-constant axial forces is converted to a radially extending force by an interaction of a three guide and actuator. The force guide is shaped to produce an essentially constant radially extending force through the entire range of motion of the arm assemblies. Preferably the radially extending force is maintained throughout each arm assembly's travel within about ten percent of the maximum radially extending force. Typically, each arm assembly is comprised of a pivoting arm and telescopic section. Typically a wheel is positioned at the joint of the pivoting arm and the telescopic section to reduce friction as the constant force centralizer moves through the tubular. In the collapsed condition where the pivoting arm and wheel are relatively close to the mandrel of the constant force centralizer the telescoping arm is in its substantially shortest state whereas in the extended condition where the pivoting arm and wheel are at their maximum distance from the mandrel the telescoping arm is in its longest state. The telescoping arm is generally necessary in order to allow the constant force centralizer to reverse direction when moving from a larger diameter tubular to a smaller diameter tubular. A portion of the telescoping arm will interact with the tubular to force the pivoting arm and wheel to retract to at least a semi-collapsed condition. By utilizing a telescoping arm in place of a solid arm, the overall length of the constant force centralizer is shorter than would otherwise be possible, and this is considered beneficial for many logging tool embodiments. [0008] It is envisioned that two pairs of arm assemblies will usually be used in a constant force centralizer. The pairs of arm assemblies are typically arranged such that a first end of the first pair and a first end of the second pair of arm assemblies extend toward each other from a first end of a mandrel and from an opposing second end of the mandrel. Generally the first pair of arm assemblies is allowed to collapse into a nested position with the second pair of arm assemblies. When fully collapsed, opposing pairs of pivoting arms overlap by some distance. The overlap and telescoping arms generally allows the tool to be shorter than a standard tool not having overlapping arms. [0009] Ovalized casing is encountered occasionally, and centralization in such conditions can be difficult. Constant force centralizers offered to date have linked arms providing lateral arm movement that is symmetric in all directions. In round casing and in vertical wells, this arrangement is adequate. However, in deviated wells where the casing is ovalized, these centralizers may not perform well. In a current embodiment typically the arms that are offset from one another at some angle, typically 90°, allow for the offset arms to provide non-symmetric arm movement in at least two directions providing centralization even in non-symmetric or ovalized wellbores or tubulars. In certain situations it has been found that non-symmetric constant force is necessary such that the tool is held in an eccentric condition within the well. BRIEF DESCRIPTION OF THE DRAWINGS [0010] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. [0011] FIG. 1 depicts a calculated and measured force curve of an embodiment of the invention. [0012] FIG. 2 depicts a calculated force curve of an alternate embodiment of the invention. [0013] FIG. 3 depicts a side view of an embodiment of the invention in its extended condition. [0014] FIG. 4 depicts an end view of an embodiment of the invention. [0015] FIG. 5 depicts a side view of an embodiment of the invention in its retracted condition. [0016] FIG. 6 depicts an end view of an embodiment of the invention in a partially extended condition in an oval tubular. [0017] FIG. 7 depicts an extended joint of an embodiment of the invention. [0018] FIG. 8 depicts a side view of an alternate embodiment of the invention in its extended condition. [0019] FIG. 9 depicts a side view of an alternate embodiment of the invention having a rotatable force guide in an extended condition of a constant force centralizer. [0020] FIG. 10 depicts an orthogonal view of a rotatable force guide. [0021] FIG. 11 depicts a side view of an alternate embodiment of the invention having an extension limiter in a limited extension condition. [0022] FIG. 12 depicts a side view of an alternate embodiment of the invention having an extension lock in a retracted and locked condition. [0023] FIG. 13 depicts a close-up of the area A from FIG. 12 . DESCRIPTION [0024] FIG. 1 depicts a graph of the measured force curve 10 versus the predicted force curve 14 of an embodiment of the present invention. The measured force curve 10 is a poly fit of the measured points 12 while the predicted force curve is a based upon a computer simulation. A perfectly flat, linear response was the original design goal, but in order to keep the mechanisms relatively simple, a slight “curve”, as depicted by the predicted force curve 14 and the measured force curve 10 was thought to be acceptable. [0025] FIG. 2 depicts a graph of the predicted force curve 20 of an alternate embodiment of the present invention. While other force ranges may be used, the predicted force curve 20 utilizes a force range of from about 40 pounds of force at the minimum diameter of just over three inches increasing to about 43 pounds of force at the mid-range diameter of 8 inches then decreasing again to about 40 pounds of force at the maximum diameter of about thirteen inches. Such a force range has less than a 10% variation across the range of applied force from the minimum diameter to the maximum diameter. [0026] FIG. 3 is a side depiction of an embodiment of a constant force centralizer 50 providing a substantially constant radially outward force throughout a predetermined range of tubular diameters. The constant force centralizer 50 has an inner mandrel 52 , beginning with the right side of the constant force centralizer 50 , and at least one axial biasing device such as axial biasing device 54 . A collar 58 is fitted to the mandrel 52 in such a manner that its position is fixed relative to the mandrel 52 . The collar 58 may be threaded, pinned, welded, or formed as an integral part of inner mandrel 52 , or connected by any other means known to the inner mandrel 52 . The axial biasing device 54 typically surrounds inner mandrel 52 and abuts collar 58 . The axial biasing device 54 also abuts a movable sleeve 62 . Typically the movable sleeve 62 is circumferential about an exterior surface of inner mandrel 52 . The movable sleeve 62 is generally only axially movable. A first end 70 and 72 of pivotal force arms 64 and 68 is attached to movable sleeve 62 . Each pivotal force arm 64 and 68 has a recess 74 and 76 . Within each recess 74 and 76 is an actuator 80 and 82 , such as a roller. Each recess 74 and 76 is sized such that when pivotal force arms 64 and 68 are in the retracted position, lying flat against inner mandrel 52 , most of the force guides 84 and 88 that extend beyond the exterior surface of inner mandrel 52 are contained within each recess 74 and 76 . The force guides 84 and 88 are fixed to the inner mandrel 52 and maybe threaded on, pinned on, or formed as an integral part of the inner mandrel 52 . It is generally the interaction between the force guides 88 and 84 with the corresponding actuators 80 and 82 that describes the constancy of the force curves such as the curves in FIGS. 1 and 2 . Each force guide 88 and 84 will have a surface such as surfaces 90 and 92 . Generally the surfaces 90 and 92 are linear surfaces at some angle α relative to the axis of mandrel 52 where the angle α provides a reasonably flat force curve. The angle α in FIG. 3 is 47°. [0027] Continuing with the left side of the constant force centralizer 50 , the constant force centralizer 50 has at least one axial biasing device such as axial biasing device 56 . A collar 100 is fixed onto a second end 102 of inner mandrel 52 . The collar 100 is typically threaded onto inner mandrel 52 but may be pinned, welded, or formed as an integral part of inner mandrel 52 . The axial biasing device 56 typically surrounds inner mandrel 52 and abuts collar 100 . The axial biasing device 56 also abuts a movable sleeve 104 . Typically the movable sleeve 104 is circumferential about an exterior surface of inner mandrel 52 . The movable sleeve 104 is generally only axially movable. A second end 106 and 108 of telescopic arms 110 and 112 is attached to movable sleeve 104 . [0028] A first end 114 and 116 of telescopic arms 110 and 112 is pivotally connected to a second end 120 and 122 of pivotal force arms 64 and 68 . Generally, at the pivotal connection where first end 114 and second end 122 as well as first end 116 and second end 120 are connected, a wheel, such as wheel 124 and 126 , a roller, a skid, or other friction reducer is attached. Generally it is at wheels 124 and 126 that the constant force is applied to the casing or other tubular in a direction perpendicular to the long axis of the constant force centralizer 50 . [0029] When the constant force centralizer is in a tubular with sufficiently small diameter, each of the pivotal force arms 64 , 68 , and telescopic arms 110 , and 112 will be in a collapsed position such that wheels 124 and 126 are at a minimal radial distance from inner mandrel 52 . With wheels 124 and 126 at their minimal radial distance from inner mandrel 52 , axial biasing device 54 is at maximum compression thereby applying the maximum normal force against movable sleeve 62 . The force applied by axial biasing device 54 is transferred to the movable sleeve 62 . The force applied by axial biasing device 54 is not necessarily constant. Movable sleeve 62 in turn transfers the force to pivotal force arms 64 and 68 . Subsequent movement of pivotal force arm 64 is guided by actuator 80 acting on surface 90 causing end 122 to move in a direction substantially perpendicular to the axis of the mandrel 52 . The dimensions of pivotal force arm 64 , actuator 80 , force guide 88 , movable sleeve 62 , collar 58 and biasing device 54 are chosen so that the force from the biasing device 54 is transferred to the wheel 124 in such manner that that force of wheel 124 against the tubular remains reasonably constant as the diameter of the tubular changes. Movement of pivotal force arm 68 is guided by actuator 82 acting on surface 92 causing end 120 to move in a direction substantially perpendicular to the axis of the mandrel 52 . The dimensions of pivotal force arm 68 , actuator 82 , force guide 84 , movable sleeve 62 , collar 58 and biasing device 54 are chosen so that the force from the biasing device 54 is transferred to the wheel 126 in such manner that that force of wheel 126 against the tubular remains reasonably constant as the diameter of the tubular changes. [0030] When the constant force centralizer 50 moves from a large diameter tubular to a smaller diameter tubular the force vectors are reversed such that the wheels 124 and 126 are forced inward exerting force through the pivotal arm 64 and 68 to the actuators 80 and 82 were the forces are redirected by the interaction of the actuators 80 and 82 with force guides 84 and 88 into movable sleeve 62 and ultimately into axial biasing device 54 . [0031] As indicated in FIG. 2 , a current embodiment of the tool produces 40 lbs of radial force at the wheels 124 and 126 at the joint between pivoting force arms 64 and 68 and telescoping arms 110 and 112 . The force response is adjustable with the nominal radial force either increased or decreased. Such increases or decreases may be adjusted where biasing devices 54 and 56 may be replaced with springs, gas chambers, etc. having proportionally higher or lower force rates. If needed, shims can add compression to the biasing devices 54 and 56 and thereby increase the axial force. A flatter force response curve, see FIGS. 1 and 2 , is achievable if a more complex shape is machined into the force guides 84 and 88 . [0032] As further indicated in FIG. 3 , the force guides 84 and 88 are generally fixed to the inner mandrel 52 of the constant force centralizer 50 . In a current embodiment. the force guides 84 and 88 have an angle α where the angle α is about 47° relative to the axis of the inner mandrel 52 achieving a substantially constant force response as indicated in FIG. 2 . The force guide angle and/or shape controls the shape of the force response curves such as the force response curves in FIGS. 1 and 2 . [0033] FIG. 4 is an end view of the fully collapsed constant force centralizer 50 . In the embodiment of the constant force centralizer depicted an outside diameter of 3.5 inches was chosen as the nominal diameter of the centralizer. A smaller outer diameter can be achieved in the centralizer design by scaling down the size of the components. [0034] In general, for wireline tools, shorter tools are preferred. As tools become shorter, their overall weight is reduced. In one embodiment of the 3.5 inch diameter constant force centralizer 100 , the total tool weight is less than 40 pounds. With this in mind, as indicated below, several unique design features were employed to minimize the tool length. As shown in FIG. 5 , one embodiment of the constant force centralizer 100 has a length of 26.8 inches. The relatively short tool length of the design is a result of offsetting the pivoting force arms 102 , 104 , and 106 . The pivoting force arm 102 is attached to movable sleeve 108 while pivoting force arm 104 is attached to movable sleeve 110 by pin 112 and pivoting force arm 106 and is attached to movable sleeve 110 by pin 114 . The pivoting force arm 102 is connected to telescoping arm 122 at the joint 132 . Also at joint 132 are wheels 116 and 117 . Telescoping arm 122 has a first portion 124 , connected to pivoting force arm 102 at joint 132 , and a second portion 126 . Second portion 126 is attached to movable sleeve 110 via pin 134 . In this embodiment the second portion 126 slides within the first portion 124 . The other two pivoting force arms 104 and 106 seen in FIG. 5 are each rotated 90° around the central axis of the constant force centralizer 100 . For ease of reference only pivoting force arm 104 will be further described. As described previously pivoting force arm 104 is attached to movable sleeve 110 by pin 112 . The pivoting force arm 104 is connected to telescoping arm 128 at the joint (not shown) where wheel 118 is attached to the constant force centralizer 100 . [0035] As can be seen in FIG. 5 the movement of the arms occurs in two planes (not shown). The two planes are perpendicular to each other and both planes contain the axis of the constant force centralizer 100 . Additionally each of the wheels 116 and 118 are offset by some axial distance D. The distance D may vary depending upon whether the arms are fully extended or fully collapsed or at some point in between. [0036] When the arms are fully open the wheels 116 and 118 are axially offset by 1.35 inches. When the arms are fully closed the wheels 116 and 118 are axially offset by 2.1 inches. With offset wheels, the centralizer 100 can traverse radial upsets in the tubular more easily, and erratic tool movement is minimized. [0037] Generally by having the telescoping arms 122 and 128 attached to their respective pivoting force arms 102 and 104 the respective axial biasing devices 140 and 142 operate to apply force to their associated wheels 116 and 118 independently. [0038] The wheels 116 , 118 , 117 and 120 , at each of the joints between the pivoting force arms 102 , 104 , and 106 and the telescoping arms 122 , 128 , and 130 are free to rotate even when the tool is completely closed to its minimum outside diameter. In the embodiment of the constant force referred to in FIG. 2 the constant force centralizer is designed to open from about 3.5 inches to about 12.7″ which is the inner diameter of typical casing that has an outer diameter of 13⅜ inches. As shown in FIG. 2 , about 40 pounds of centralizing force is active across that entire range. [0039] In an embodiment of the current invention of the constant force centralizer 100 from FIG. 5 as further depicted in FIG. 6 the pivoting force arm 102 is paired with the pivoting force arm 107 on the opposite side of the constant force centralizer 100 . The opposing pivoting force arms 102 and 107 move symmetrically with one another. The telescoping arm 128 is paired with the telescoping arm 130 on the opposite side of the constant force centralizer 100 . The opposing telescoping arms 128 and 130 move symmetrically with one another. [0040] The telescoping arms 128 and 130 arms are generally orthogonal to the pivoting force arms 102 and 107 . The pivoting force arms 102 and 107 are typically coupled to each other such that the axial biasing device 140 drives both of the pivoting force arms 102 and 107 . While the telescoping force arms 128 and 130 may be linked to the same movable sleeve 108 as the pivoting force arms 102 and 107 the telescoping mechanism does not allow force to be applied by movable sleeve 108 to the telescoping force arms 128 and 130 . In oval holes, conventional wisdom suggests that one pair of arms, either the pivoting force arms 102 and 107 or the telescoping arms 128 and 130 , will naturally align with the “long axis” of the hole. In FIG. 6 the long axis of the tubular 136 is depicted as being 12.4 inches as shown by reference numeral 133 while the short axis of the tubular 136 is depicted as being 11.3 inches as shown by reference numeral 135 . The position of the constant force centralizer as depicted in FIG. 6 is preferable and is likely to maintain good tool centralization in oval holes. [0041] Several features of the constant force centralizer are intended to minimize rolling friction. The wheels 150 and 152 , as depicted in FIG. 7 , in an embodiment of the constant force centralizer are preferably as large in diameter as possible, here 1.3 inches in diameter as shown by reference numeral 154 , without exceeding the desired 3.5 inch constant force centralizer outside diameter. Maximizing the wheel diameter allows each wheel 150 and 152 to last longer and roll more smoothly across irregularities in the tubular. Typically, each joint between the telescoping arm 158 and the pivoting arm 156 arm has two wheels 150 and 152 at the joint. Each wheel rolls independently on ball bearings 160 . [0042] As shown in FIG. 8 , when an embodiment of the constant force centralizer 200 is fully open, the pivoting force arms 202 and 204 are at an angle β relative to the axis of the constant force centralizer 200 . In this instance angle β is 30°. The telescoping arms 206 and 208 are at an angle Ω relative to the axis of the constant force centralizer 200 . In this instance angle Ω is 35°. Generally, it is desired to have the angles β and Ω as shallow as possible in order to help the constant force centralizer 200 slide through any restrictions that may exist within the tubular. [0043] FIG. 9 is a depiction an alternative embodiment of the constant force centralizer 300 . In some instances it has been found desirable to allow the inner mandrel 302 to remain fixed to the wireline or other transporting device while allowing the components of the centralizer assembly including the rotatable force guide 304 , pivoting force arms 306 , telescoping arms 308 , first axial biasing device 312 , first movable sleeve 316 , second axial biasing device 314 , second movable sleeve 318 , and other associated portions of the centralizer assembly to rotate around the inner mandrel 302 . By allowing the centralizer assembly to rotate around the inner mandrel 302 the wireline (not shown) avoids becoming twisted thereby avoiding any torque build up on account of constant force centralizer 300 . [0044] FIG. 10 is a depiction of the rotatable force guide 304 from FIG. 9 . The rotatable force guide 304 typically consists of a first-half 356 and a second half 358 . Each half 356 and 358 has a semicircular section such as 366 and semicircular section 364 each half 356 and 358 also has at least a portion of the force guide 304 attached to the semicircular sections 366 and 364 . The upper force guide includes a relatively linear surface 370 set at an angle α to the central axis of the inner mandrel 302 of the constant force centralizer 300 . The upper force guide also includes a means to pivotally attach a limiting arm (not shown) such as providing a slot 372 for a wrist pin (not shown). The lower force guide includes a relatively linear surface 368 set at an angle α to the central axis of the inner mandrel 302 of the constant force centralizer 300 . The lower force guide also includes a means to pivotally attach a limiting arm (not shown) such as providing a slot 374 for a wrist pin (not shown). [0045] In the embodiment shown the rotatable force guide 304 is applied to the inner mandrel 302 by placing each half 356 and 358 such that the semicircular portions 364 and 366 surround the inner mandrel 302 . Then using bolts such as bolts 362 and 360 to fix each half 356 and 358 in place around inner mandrel 302 . It is envisioned that any known means of manufacturing a rotatable force guide could be used for instance in some instances the force guide 304 could be machined out of a solid piece of material and then slid onto the mandrel 302 from one end. [0046] FIG. 11 is a depiction an alternative embodiment of the constant force centralizer 400 . In some instances it has been found desirable to limit the outward translation of the pivoting force arm 402 in turn limiting the outward translation of the telescoping force arm 404 and wheel 406 . Such a limitation may be useful in, for instance, circumstances where the constant force centralizer 400 may pass through very large openings such as when it passes through a blowout preventer which might cause damage to the constant force centralizer 400 . [0047] One such extension limiter may use a link 410 attached to the inner mandrel 412 or as is shown in FIG. 11 a first end of link 410 is attached to the rotatable force guide 414 by wrist pin 416 within slot 472 . A second end of link 410 is attached to pivoting force arm 402 by wrist pin 418 within slot 420 . Wrist pin 418 is configured such that it may slide within slot 420 depending upon the extension position of wheel 406 as wheel 406 moves towards inner mandrel 412 wrist pin 418 will move towards wheel 406 within slot 420 . However as wheel 406 moves away from inner mandrel 412 wrist pin 418 moves within slot 420 towards movable sleeve 422 . Eventually wrist pin 418 reaches the end of slot 420 closest to movable sleeve 422 whereupon wheel 406 is prevented from moving any further radially outward from inner mandrel 412 . [0048] FIG. 12 is a depiction of an alternative embodiment of a portion of a constant force centralizer 500 . In most instances it has been found to be preferable to restrict any expansion of the force pivoting arms 502 , 504 , and 506 as well as the associated telescoping arms 508 , 510 , and 512 until at least the constant force centralizer 500 has been deployed into the tubular or wellbore. Preferably a lock will maintain the pivoting force arms and telescoping arms in the retracted position until some predetermined parameter is reached. For instance a pressure actuated retaining pin 520 may be used where the pressure actuated retaining pin 520 is designed to protrude from the force guide 522 when the constant force centralizer 500 is below some preset pressures such as atmospheric pressure. The portion of the pressure actuated retaining pin 520 that protrudes from the force guide 522 engages pivoting force arm 502 and prevents it from opening. When the constant force centralizer 500 enters the tubular the external pressure may be increased such that at some predictable point the pressure will be sufficient to force the pressure actuated retaining pin 520 inward into its recess within the force guide 522 . With the pressure actuated retaining pin 520 moved inward the pivoting force arm 502 is released so that the wheel 524 may move radially outward to engage the tubular at the predetermined force level. [0049] FIG. 13 is section A from FIG. 12 . FIG. 13 depicts force guide 522 having the pressure actuated retaining pin 520 within recess 524 . In the embodiment shown in FIG. 13 a pressure actuated retaining pin is utilized. In other instances the retaining pin could be actuated by temperature, elapsed time, a sacrificial wear pin, by a chemical reaction, or by an electrical signal. A portion 526 of the pressure actuated retaining pin 520 extends from force guide 522 into a port 528 within pivoting force arm 502 . The pressure actuated retaining pin 520 and recess 524 form a chamber 530 sufficient to allow the pressure actuated retaining pin 522 to move into the recess 524 within force guide 522 upon the application of sufficient force to port 528 and acting upon the portion of the pressure actuated retaining pin 522 that extends into port 528 . The pressure actuated retaining pin 522 may be held outwardly extended by the force exerted upon the pressure actuated retaining pin 522 by the pivoting force arm 502 and/or may have any other means known in the industry for securing the pressure actuated retaining pin 522 . [0050] While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible. Variations are likely to be beneficial when employed in tools such as calipers, anchoring devices, eccentering devices, and downhole tractors. [0051] While the embodiments shown are described with the intention of maintaining a substantially constant radial force across the full operating range of the device, it is understood that, if desired, the mechanism can be modified to achieve different radial forces within different size tubulars. [0052] Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.

A constant force device has at least a first non-constant axial force driving the first set of arms and a second non-constant axial force driving the second set of arms, where the two sets of arms are offset from one another by 90°. Each of the non-constant axial forces is converted to a radially extending force by the interaction of a force guide and actuator. The force guide is attached to the inner mandrel of the constant force device and is shaped to produce an essentially constant radially extending force through the entire range of motion of the arms. Typically each arm of the pair of arms has a pivoting arm and a telescoping arm where the joint between the pivoting arm and telescoping arm has one or more wheels to reduce friction as the constant force device moves through the tubular. Generally the first pair of arms is opposed to and overlaps by some distance the second pair of arms where the second pair of arms is 90° offset from the first pair of arms. Additional features may include friction reducing members at the joint between the telescoping arm and the pivoting arm, an extension lock, extension limiters, and rotating force guides.

CROSS-REFERENCE [0001] Provisional Patent Applications covering the below described invention were submitted, via Express Mail, which bore label number EM 425754569 US and EG 835094455 US, and were assigned application Nos. 61/341014 and 61/462572. The inventors claim the priority date of said Provisional Patent Applications. GOVERNMENT RIGHTS [0002] Not Applicable. BACKGROUND [0003] The useful properties of plant ethylene receptor inhibitors have been well documented. For example, 1-methylcyclopropene (CAS #3100-04-7), a substituted cyclopropene (hereafter, simply referred to as “1-MCP”), has been demonstrated to help increase the shelf life and storage characteristics of many fruits and flowers. [0004] More recently, it has been demonstrated that 1-MCP, or analogues thereof, can be used in agricultural applications. Specifically, 1-MCP, and analogues thereof, are used to retard the ripening process in plants, which allows the plant materials to last much longer than untreated plants. Additionally, 1-MCP, and analogues thereof, are used for crop protection during times of stress that includes drought, excessive heat, and excessively low temperatures. With regard to the above specified agricultural applications and without limitation, the 1-MCP analogue compounds may be considered to be related compounds which have similar uses as 1-MCP in agricultural applications. The analogues of 1-MCP with regard to the above specified agricultural applications involve compounds which contain the cyclopropene moiety. The compounds cyclopropene, 3-methylcyclopropene, 1-ethylcyclopropene, 1,2-dimethylcyclopropene, 1,3-dimethylcyclopropene, and 3,3-dimethylcyclopropene have similar agricultural significance, albeit the aforementioned compounds are weaker plant ethylene receptor inhibitors in comparison to 1-MCP, and they are included amongst many other releasable analogue compounds that are covered by this technology. Generally, these cyclopropene containing compounds are regarded as plant ethylene receptor antagonist, and inhibit plant senescence and abscission in a wide variety of plant species. In particular, the cyclopropene containing analogue 1-trifluoromethylcyclopropene (hereafter, simply referred to as “1-TFMCP”) is a plant ethylene receptor antagonist with different characteristics than 1-MCP which include slightly increased water solubility and increased penetration through waxy or otherwise lipophilic layers of some plant species. [0005] Unfortunately, 1-MCP and 1-TFMCP are highly unstable gases, and so cannot be conventionally applied, or easily stored for long periods of time. Presently, the only commercially available forms of 1-MCP are in highly dilute mixtures and 1-TFMCP is not commercially available. For the foregoing reasons, there is a need for a solution to the problems associated with the shelf-life, long term storage, transport, and release of 1-MCP, 1-TFMCP, and additional cyclopropene containing analogues. SUMMARY [0006] The above listed applicants have identified a solution to the problems associated with the shelf-life, long term storage, transport, and release of 1-MCP, 1-TFMCP, and analogues thereof, on an as needed basis by covalently linking 1-MCP, 1-TFMCP, or analogues thereof, directly to a molecular compound which, upon activation, releases the compound 1-methylcyclopropene, 1-TFMCP, or analogues thereof. Additionally, some compounds that are used in this manner to release 1-MCP may be further stabilized via a reversible reaction forming a ketal (as an asymmetric ortho-ester), which only requires exposure to a mildly acidic aqueous solution to afford deprotection, thereby yielding the immediate light and/or heat active precursor compound and either a diol or two equivalents of an alcohol. The light and/or heat active precursor may then yield the cyclopropene or substituted cyclopropene (such as 1-MCP, 1-TFMCP, etc.) upon further exposure to light and/or heat. This technology allows for formulations that include solid mixtures, aqueous solutions, non-aqueous solutions, colloidal dispersions, or direct application of the release vent such that the 1-MCP Release System can be conventionally applied, which is then activated by light and/or heat to release the 1-MCP, 1-TFMCP, or analogue thereof. DRAWINGS [0007] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawings where: [0008] FIG. 1 shows the general light and/or heat driven release mechanism contemplated herein; [0009] FIG. 2 shows the general stereochemistry of 2-oxa-bicyclo[2.1.0]penta-3-one; [0010] FIG. 3 shows the general stereochemistry of 3,4-dioxa-bicyclo[4.1.0]hepta-2,5-dione; [0011] FIG. 4 shows the manner by which 3,4-dioxa-bicyclo[4.1.0]hepta-2,5-dione may proceed through a stable intermediate comprising 2-oxa-bicyclo[2.1.0]penta-3-one in a multi-step reaction scheme ultimately resulting in the generation of 1-MCP or analogues thereof from 3,4-dioxa-bicyclo[4.1.0]hepta-2,5-dione; and [0012] FIG. 5 shows some possibilities of value added aryl-unit containing products that may be created from different configurations of Compound 4. DESCRIPTION [0013] The strategies discussed herein pertaining to the capture and release, and to release without capture of 1-MCP, 1-TFMCP, and analogues thereof, are based upon light and/or heat driven release mechanisms. When the covalently linked system is exposed to light and/or heat, 1-MCP, 1-TFMCP, or analogue thereof, is released along with the linked molecule. The release system formulations include one, or more, of such 1-MCP, 1-TFMCP, or other analogue releasing compounds, and in various proportions or mixtures thereof. Here, the term mixtures includes, but is not limited to, combinations of compounds within a given method (described herein), combinations of compounds spanning one or more methods (described herein), combinations of stereo-isomers, where they exist, and all permutations thereof, and also where any of the methods contained herein are used in combination with a different method in the general field of practice. [0014] In addition to light, heat may also be used to generate the desired 1-MCP, 1-TFMCP, or related analogue in some cases. Thus, light, heat, or combinations of light and heat may be used in these reactions to generate the desired compounds. The amount of heat and/or light energy required for the release of 1-MCP, 1-TFMCP, or analogues thereof, is dependent upon the specific precursor compound and the specific formulation in which it is contained, amongst other determinants. Thus, the heat and light energy requirements for the release of 1-MCP, 1-TFMCP, or analogues thereof, can be attenuated to meet a desired release profile. Specific compounds more generally represented by Markush Structures of Compounds 1 through 8 can be obtained such that very high thermal stability is imparted, but a low light energy threshold is obtained. In the aforementioned example, the compound will exhibit long shelf life, even at high temperatures, so long as exposure light is avoided during storage. Upon exposure to light, the 1-MCP, 1-TFMCP, or analogue thereof is released. [0015] Some of the precursor compounds (such as Compound 1) used to generate 1-MCP, 1-TFMCP, or analogues thereof, may be further stabilized as their respective ketal (as an asymmetric ortho-ester), which affords increased stability to heat and/or light. Upon exposure of such compounds to acidic aqueous solutions under mild conditions, the immediate precursor is generated along with the respective diol or two equivalents of an alcohol containing compound. The immediate precursor will then yield 1-MCP, 1-TFMCP, or analogues thereof, and carbon dioxide upon further exposure to heat and/or light. [0016] Without limitation, the 1-MCP Release System more fully set forth below is comprised of a precursor molecule (Compound 1 through 8), which upon activation to an excited state, generates 1-MCP, 1-TFMCP, or analogue thereof, and one or more by-products. The by-product(s) may consist of one or more gases. In addition, the by-product(s) may also entail the release of an additional molecule which contains an aryl group. The aryl group released may be, by design, a “value added material.” By way of example and without limitation, such value added material(s) may be a pesticide (such as a herbicide, insecticide, fungicide, rodenticide, and/or acaracide), herbicide, bee attractant, or preservative. [0017] To date the below identified molecules and protocols have been identified as addressing the problems associated with the capture and release, and release without capture of 1 -MCP, 1-TFMCP, or analogues thereof. These aforementioned molecules are referred to as Compounds 1 through 8, and the aforementioned methods are referred to as Methods 1 through 4 in the context of this patent application. [0018] The 1-MCP and analogues thereof, may be described as two general sets of reaction products which contain a cyclopropene moiety. These two product sets can be represented as Product 1 or Product 2, below, with respect to the methods detailed more fully herein. [0000] [0019] Where R 1 or R 4 of Product 1 is comprised of a methyl group (—CH 3 ), and all other R 1 through R 4 are hydrogens, Product 1 will be 1-MCP, below. Where R 1 or R 3 of Product 2 is comprised of a methyl group (-CH 3 ), and all other R 1 through R 4 are hydrogens, Product 2 will be 1-MCP, below. Where R 1 or R 4 of Product 1 is comprised of a tri-fluoromethyl group (—CF 3 ), and all other R 1 through R 4 are hydrogens, Product 1 will be 1-TFMCP, below. Where R 1 or R 3 of Product 2 is comprised of a tri-fluoromethyl group (—CF 3 ), and all other R 1 through R 4 are hydrogens, Product 2 will be 1-TFMCP, below. [0000] Compound 1: Analogues of 2-oxa-bicyclo[2.1.0]penta-3-one [0020] Compound 1 (analogues of cyclopropane annulated beta-lactone), which may also be referred to as analogues of 2-oxa-bicyclo[2.1.0]penta-3-one, below, has been found to be reactive in strategies to generate 1-MCP, and analogues thereof, by heat and/or light. [0000] [0000] The general stereochemistry of Compound 1 may be more clearly seen in FIG. 2 , where A and B represent the two general enantiomers of Compound 1, where they exist. [0021] The general reaction of Compound 1 upon exposure to light and/or heat, depending on the composition of the identified R groups, yields Product 1, above, where the R groups of Product 1 correspond to the same substituents on Compound 1, and one equivalent of carbon dioxide. Sunlight, or artificial light sources may be used. Increased rates may be obtained by using sonication (ultrasound) and/or a LASER as the source of light and/or in conjunction with a photo-catalyst, such as one comprising palladium. The product entailing Product 1 in this case will generally be an achiral product or a racemic mixture where they exist. It is possible to obtain a non-racemic product composition by this method under certain conditions, such as when the light source is polarized. [0022] The R groups for Compound 1 may, independently for each respective R 1 through R 4 , be comprised of a hydrogen (—H), chlorine (—Cl), or fluorine (—F) atom, or group comprised of methyl (—CH 3 ), ethyl (—CH 2 CH 3 ), ethylene (—CHCH 2 ), ethyne (—CCH), n-propyl (—CH 2 CH 2 CH 3 ), iso-propyl (—CH(CH 3 ) 2 ), cyclopropyl (—CH(CH 2 ) 2 ), tert-butyl (—C(CH 3 ) 3 ), propene (—CHCHCH 3 or —CH 2 CHCH 2 ), cyclopropene (—CH(CH) 2 or —C(CH)CH 2 ), propyne (—CCCH 3 or —CH 2 CCH), hydroxyl (—OH), methylalcohol (—CH 2 OH), ethylalcohol (—CH 2 CH 2 OH or —CH(OH)CH 3 ), ethyldiol (—CH(OH)CH 2 (OH)), propanol (—CH(OH)CH 2 CH 3 or —CH 2 CH(OH)CH 3 or —CH 2 CH 2 CH 2 OH), propandiol (—CH(OH)CH(OH)CH 3 or —CH(OH)CH 2 CH 2 OH or —CH 2 CH(OH)CH 2 OH), methylether (—OCH 3 ), ethylether (—OCH 2 CH 3 ), fluoromethyl (—CH 2 F), difluoromethyl (—CHF 2 ), trifluoromethyl (—CF 3 ), fluoroethyl (—CFHCH 3 or —CH 2 CH 2 F), perfluoroethyl (—CF 2 CF 3 ), fluoropropyl (—CHFCH 2 CH 3 or —CH 2 CHFCH 3 or —CH 2 CH 2 CH 2 F) perfluoropropyl (—CF 2 CF 2 CF 3 or —CF(CF 2 ) 2 ), chloromethyl (—CH 2 Cl), dichloromethyl (—CHCl 2 ), trichloromethyl (—CCl 3 ), chloroethyl (—CClHCH 3 or —CH 2 CH 2 Cl), perchloroethyl (—CCl 2 CCl 3 ), chloropropyl (—CHClCH 2 CH 3 or —CH 2 CHClCH 3 or —CH 2 CH 2 CH 2 Cl), perchloropropyl (—CCl 2 CCl 2 CCl 3 or —CCl(CCl 2 ) 2 ), cyano (—CN), aldehyde (—C(O)H), carboxylic acid (—C(O)OH), carboxylate (—C(O)O), carbomethoxy (—C(O)OCH 3 ), carboethoxy (—C(O)OCH 2 CH 3 ), dimethyl amine (—N(CH 3 ) 2 ), or acid chloride (—C(O)Cl). [0023] The products of 1-MCP and carbon dioxide may be obtained from either enantiomer of Compound 1 when R 1 or R 4 is a methyl group and all other R groups are hydrogen. The products of 1-TFMCP and carbon dioxide may be obtained from either enatiomer of Compound 1 when R 1 or R 4 is a trifluoromethyl group and all other R groups are hydrogen. Compound 2: Analogues of 2-oxa-bicyclo[2.1.0]penta-3-one ketal [0024] The Compound 1 may be generated via a reversible reaction from its respective analogue ketal (an asymmetric ortho-ester), identified below as Compound 2 (analogues of 2-oxa-bicyclo[2.1.0]penta-3-one ketal). Here, the R 1 , R 2 , R 3 , and R 4 groups may be independently comprised of any of the R groups discussed above for Compound 1. The R 5 and R 6 groups may share a covalent bond (shown as a dashed line, below) or may be two independent subunits. Independently, for R 5 and R 6 , they may be comprised of a methyl (—CH 3 ), ethyl (—CH 2 CH 3 ), or propyl (—CH 2 CH 2 CH 3 ) groups. Where R 5 and R 6 share a covalent bond, R 5 and R 6 together may be an ethyl (—CH 2 CH 2 —) or propyl (—CH(CH 3 )CH 2 —) group. [0000] [0025] A general reaction to form the ketal protected variant of Compound 1 (as an asymmetric ortho-ester; Compound 2), utilizes the light initiated [2+2] reaction of Product 1 (now, as a reactant) with a dimethyl carbonate, diethyl carbonate, ethylene carbonate, or propylene carbonate. The reaction can be carried out in a wide variety of solvent media (excepting acidic aqueous solutions), or under vacuum conditions for the gas-phase reaction. The use of the above molecules in a photo-induced [2+2] reaction yields Compound 2, where R 5 and R 6 are both methyl (—CH 3 ) or ethyl (—CH 2 CH 3 ) for the case where dimethyl carbonate, or diethyl carbonate are used, respectively, and yields Compound 2 where R 5 and R 6 share an ethylene bridge (—CH 2 CH 2 —) for the case that ethylene carbonate is used, or share a methyl substituted ethylene bridge (—CH(CH 3 )CH 2 —) for the case that propylene carbonate is used. [0026] When R 1 or R 4 is a methyl group on Product 1 (1-MCP), and all other R groups are hydrogens, 1-MCP may be sequestered by a photo-induced [2+2] reaction with the aforementioned carbonates. Such a reaction yields Compound 2 where R 1 is a methyl group and R 2 , R 3 , and R 4 are hydrogens, or Compound 2 where R 4 is a methyl group and R 1 , R 2 , and R 3 are hydrogens. When R 1 or R 4 is a trifluoromethyl group on Product 1 (1-TFMCP), and all other R groups are hydrogens, 1-TFMCP may be sequestered by a photo-induced [2+2] reaction with the aforementioned carbonates. Such a reaction yields Compound 2 where R 1 is a trifluoromethyl group and R 2 , R 3 , and R 4 are hydrogens, or Compound 2 where R 4 is a trifluoromethyl group and R 1 , R 2 , and R 3 are hydrogens. [0027] Upon exposure of Compound 2 to excess water in the presence of H + (an aqueous acidic solution), the following respective alcohol or diol (as Product 3, below) and Compound 1 are generated under mild conditions. [0000] Compound 3: Analogues of 3,4-dioxa-bicyclo[4.1.0]hepta-2,5-dione [0028] Another important molecule is Compound 3 below, (analogues of 3,4-dioxa-bicyclo[4.1.0]hepta-2,5-dione). Here, the R 1 , R 2 , R 3 , and R 4 groups may be independently comprised of any of the R groups discussed above for Compound 1. [0000] [0029] The general stereochemistry for Compound 3 is illustrated in FIG. 3 , where A and B represent the two general stereoisomers. Both enantiomers of Compound 3, where they exist, are active in generating Product 1. [0030] The general reaction for Compound 3 to produce cyclopropenes and substituted cyclopropenes (as Product 1, above) requires the exposure of Compound 3 to light and/or heat and generates products consisting of Product 1, where R 1 through R 4 of Compound 3 correspond to R 1 through R 4 of Product 1, and two equivalents of carbon dioxide. Sunlight, or artificial light sources may be used. Increased rates may be obtained by using sonication (ultrasound) and/or a LASER as the source of light and/or a light source in conjunction with a photo-catalyst, such as one comprising palladium. [0031] For the case that 1-MCP is to be generated from Compound 3, R 1 or R 4 is comprised of a methyl group and all other R groups are hydrogens and upon exposure to light and/or heat 1-MCP and two equivalents of CO 2 are produced. For the case that 1-TFMCP is to be generated from Compound 3, R 1 or R 4 is comprised of a trifluoromethyl group and all other R groups are hydrogens and upon exposure to light and/or heat 1-TFMCP and two equivalents of CO 2 are produced. [0032] In addition, when subject to light and/or heat Compound 3 may proceed through a stable intermediate comprising Compound 1 in a multi-step reaction scheme ultimately resulting in the generation of 1-MCP or analogues thereof (Product 1) from Compound 3 as illustrated in FIG. 4 . Compound 4: Analogues of tetracyclo[5.2.1.0 2,6 .0 3,5 ]deca-8-en-10-one [0033] Another important molecule is Compound 4, below, (analogues of tetracyclo[5.2.1.0 2,6 . 0 3,5 ]deca-8-en-10-one). [0000] [0000] Here, the R 1 or R 4 must be comprised of a methyl group (—CH 3 ), or a trifluoromethyl group (—CF 3 ) and all other R 1 through R 4 are protons (—H). Both the R 1 and R 4 groups of Compound 4 are in an eclipsed (cis) conformation, as are the R 5 and R 10 groups. The R 5 through R 10 groups may, independently, be comprised of any of the groups discussed, above, for Compound 1. Additionally, any of the R 5 through R 10 groups may, independently, be comprised of a phenyl (—C6H5), a sodium phenoxide (—C6H4ONa), or a substituted phenyl group where the substituents (five total substituents including protons) on the phenyl group may be any of the groups discussed above for Compound 1. It is preferable that at least one of R 5 through R 10 be comprised of something other than hydrogen. [0034] There are several analogues of Compound 4, which may be represented by the Markush Structures, below, where the primary difference between the respective compounds pertains to their endo, and/or exo orientations. These orientations are (endo, endo), (endo, exo), (exo, exo), and (exo, endo) for the parent tetracyclo[5.2.1.0 2,6 .0 3,5 ]deca-8-en-10-one compounds, below, Compound 4A, Compound 4B, Compound 4C, and Compound 4D, respectively, where bond angles have been distorted for labeling purposes. Due to steric hindrance effects, Compound 4B and Compound 4D generally exhibit greater stability than Compound 4A and Compound 4C, but any of the isomers and stereoisomers of Compounds 4A through 4D are suitable for producing Product 1 upon exposure to light or to light and heat. [0000] [0035] When Compound 4 is exposed to light or light and heat it yields one equivalent each of carbon monoxide, Product 1 as 1-MCP (if R 1 or R 4 is a methyl group) or 1-TFMCP (if R 1 or R 4 is a trifluoromethyl group), and Product 4 (below). Sunlight or artificial light sources may be used. Increased rates may be obtained by using sonication (ultrasound) and/or a LASER as the source of light and/or a light source in conjunction with a photo-catalyst, such as one comprising palladium. [0000] [0036] For the case where any one of R 5 , R 6 , R 7 , R 8 , R 9 , or R 10 is a methyl ester (and all remaining R groups are protons) the light activated released compounds will be carbon monoxide, and either 1-MCP (where R 1 or R 4 is a methyl group) or 1-TFMCP (where R 1 or R 4 is a trifluoromethyl group), and methylbenzoate as Product 4 (a common bee attractant). [0037] Similarly, amongst other possibilities, the aromatic system can be chosen to be a fungicide, preservative agent, or insect repellant as is the case for the released aromatic compounds depicted in FIG. 4 . The list of potential “value added” aryl-unit containing products (as Product 4) afforded by Compound 4 are numerous. Many common pesticides (including herbicides, insecticides, fungicides, rodenticides, and/or acaracides, by way of example), bee attractant, preservative and other agrichemical compounds have been identified that are potential “value added” side products (as Product 4) of Compound 4 concomitant with the release of 1-MCP or 1-TFMCP. Compound 5: Analogues of tricyclo[3.2.2.0 2,4 ]nona-6,8-diene [0038] Another important molecule is Compound 5, below, (analogues of tricyclo[3.2.2.0 2,4 ]nona-6,8-diene), where bond angles are shown distorted for labeling purposes (R 1 and R 4 are in an eclipsed (cis) conformation). [0000] [0000] Here, the convention of using “w” and “x” components represent the adjacent carbon atoms of the general substituents containing an ethylene bridge or aromatic ring which may or may not contain a silyl diether; A, B and C, respectively, below, where dashed lines (on A, B, and C) are used to indicate the covalent bonds to the bridgehead carbons of Compound 5 (indicated with arrows “a” and “b” for “w” and “x”, respectively). The “y” and “z” components, likewise represent the adjacent carbon atoms of the same general substituents A, B and C, where “y” replaces “w” and “z” replaces “x” in each of A, B, and C, and they are now denoted as A′, B′ and C′ and their corresponding R groups are now denoted as R n ′. In this manner, the six (non-equivalent) general permutations for Compound 5 can be expressed as AA′, AB′, AC′, BB′, BC′, and CC′. [0000] [0000] As an example, the Compound represented by 5AB′ is shown below, where the w, x, y, and z labels have been removed. [0000] [0039] Here, the R 1 or R 4 must be comprised of a methyl group (—CH 3 ), or a trifluoromethyl group (—CF 3 ) and all other R 1 through R 4 are protons (—H). All other R and R′ groups of Compound 5 may be comprised of any of the substituents under Compound 1. [0040] When Compound 5 is exposed to heat, one equivalent each of Product 1 and Product 5, below, are yielded. Where R 1 or R 4 is a methyl group (—CH 3 ) and all other R 1 through R 4 are hydrogens, the Product 1 component will be 1-MCP. Where R 1 or R 4 is a trifluoromethyl group (—CF 3 ) and all other R 1 through R 4 are hydrogen, the Product 5 component will be 1-TFMCP. Akin to the Compound 4 and analogues thereof, all R groups beyond R 1 through R 4 should be chosen to entail the release of a benign or beneficial compound containing an aromatic moiety (instead of benzene, in the case of Compound 5AA′). Again, the list of potential “value-added” compounds is quite large. Where Compound 5AA′ is used, and any one of R 5 , R 6 , R 7 , R 8 , R 7 ′, or R 8 ′ is comprised of a methyl ester group, and all other R 5 through R 8 ′ are hydrogens, the yielded product will contain (as Product 5AA′) a methylbenzoate (a common bee attractant). Sonication (ultrasound) can be used to increase rates. [0000] Method 1. Release of 1-MCP via Exposure of 2(5H)-furanone & 2(3H)-furanone and Analogues Thereof to Light [0041] Under Method 1, Compound 6 (analogues of 2(5H)-furanone) and Compound 7 (analogues of 2(3H)-furanone), below, may be used to convey the general compounds that when exposed to light and/or heat release 1-MCP, or analogues thereof, as Product 1 and/or Product 2 in addition to one equivalent of carbon dioxide. The reaction pathway may involve a proton migration and bond shift such that Product 1 or Product 2 may be produced, depending upon the substituents (and wavelength of light utilized). The intermediate in this reaction is thought to involve Compound 1. Where Product 1 or Product 2 is to be comprised of 1-MCP, it is preferable that for both Compound 6 and Compound 7, R 3 or R 4 is comprised of a methyl group, and all other R are protons. Where Product 1 or Product 2 is to be comprised of 1-TFMCP, it is preferable that for both Compound 6 and Compound 7, R 3 or R 4 is comprised of a trifluoromethyl group, and all other R are protons. It is also preferred that the solution media used (if any) be transparent with a low cut-off absorption. Sunlight or artificial light sources may be used. Increased rates may be obtained by using sonication (ultrasound) and/or a LASER as the source of light and/or a light source in conjunction with a photo-catalyst, such as one comprising palladium. [0000] [0000] Each R group for Compound 6 and Compound 7 may be comprised of any of the R groups discussed for Compound 1. [0042] When exposed to light in the ultra-violet Compound 6 yields one equivalent of product comprised of Product 1 and/or Product 2 and one equivalent of carbon dioxide. When exposed to light in the ultraviolet range Compound 7 yields one equivalent of product comprised of Product 1 and/or Product 2, and one equivalent of carbon dioxide. Where R 4 or R 3 of Compound 6 is comprised of a methyl group and all other R are protons, Compound 6 yields one equivalent of 1-MCP (as Product 1 or Product 2) and one equivalent of carbon dioxide under ideal conditions when exposed to a light source. Where R 4 or R 3 of Compound 6 is comprised of a trifluoro-methyl group and all other R are protons, Compound 6 yields one equivalent of 1-TFMCP (as Product 1 or Product 2) and one equivalent of carbon dioxide under ideal conditions when exposed to a light source. [0043] Where R 4 or R 3 of Compound 7 is comprised of a methyl group and all other R are protons, Compound 7 yields one equivalent of 1-MCP (as Product 1 or Product 2) and one equivalent of carbon dioxide under ideal conditions when exposed to a light source. Where R 4 or R 3 of Compound 7 is comprised of a trifluoromethyl group and all other R are protons, Compound 7 yields one equivalent of 1-TFMCP (as Product 1 or Product 2) and one equivalent of carbon dioxide under ideal conditions when exposed to a light source. [0044] Sunlight or artificial light sources may be used. Increased rates may be obtained by using sonication (ultrasound) and/or a LASER as the source of light and/or a light source in conjunction with a photo-catalyst, such as one comprising palladium. Method 2: Release of 1-MCP via Exposure of Analogues of 3-oxabicyclo[3.1.0]hexane-2,4-dione to Light [0045] Under Method 2, Compound 8 (analogues of 3-oxabicyclo[3.1.0]hexane-2,4-dione), below, may be used to convey the general compounds that when exposed to light release 1-MCP, or analogues thereof. Compound 8, when exposed to light, yields one equivalent each of Product 1, carbon dioxide, and carbon monoxide. For the case that R 1 or R 4 are comprised of a methyl group and all other R are protons in Compound 8, the yielded products will be one equivalent each of 1-MCP (as Product 1), carbon dioxide, and carbon monoxide. For the case that R 1 or R 4 are comprised of a trifluoromethyl group and all other R are protons in Compound 8, the yielded products will be one equivalent each of 1-TFMCP (as Product 1), carbon dioxide, and carbon monoxide. [0046] Sunlight or artificial light sources may be used, but it is preferred that a high intensity light source in the ultraviolet range be used. Increased rates may be obtained by using sonication (ultrasound) and/or a LASER as the source of light and/or a light source in conjunction with a photo-catalyst, such as one comprising palladium. [0000] [0000] Each of the R groups identified for Method 2 may be comprised, independently for each, of any of the groups discussed for Compound 1. Method 3: Release of 1-MCP and a Value Added Compound via Exposure of Analogues of tetracyclo[5.2.1.0 2,6 .0 3,5 ]deca-8-en-10-one to Light or Light and Heat [0047] The representative parent compound for Method 3 which releases 1 -MCP (as Product 1), carbon monoxide, and an Aromatic functionality containing by-product (as Product 4) may be illustrated by Compound 4 and its analogues identified above where R 1 or R 4 are comprised of a methyl group and all other R, through R 4 are protons. The representative parent compound for Method 3 which releases 1-TFMCP (as Product 1), carbon monoxide, and an Aromatic functionality containing by-product (as Product 4) may be illustrated by Compound 4 and its analogues identified above where R 1 or R 4 are comprised of a trifluoromethyl group and all other R 1 through R 4 are protons. The general reaction of Compound 4 upon exposure to light or to light and heat is one equivalent each of carbon monoxide, Product 1, and Product 4. Where any one of R 5 through R 10 are comprised of a methylester group and all other R 5 through R 10 are protons, the Product 4 component will be methylbenzoate (a common bee attractant). All other R, besides R 1 through R 4 may be any of the substituents discussed for Compound 1, above. Again, there are several analogues of the parent compound, which may be represented by Compounds 4A, 4B, 4C, and 4D, above, where the primary difference between the respective compounds pertains to their endo, and/or exo orientations. [0048] The general reaction involving Compound 4 begins with a loss of carbon monoxide concomitant with bond shift and bond cleavage resulting in the loss of carbon monoxide, which may be initiated by either heat or light. The second reaction step entails a retro[2+2] reaction to form Product 1 and Product 4, which is initiated by light absorbance, and is driven by the formation of an aromatic Product 4. Sunlight or artificial light sources may be used. Increased rates may be obtained by using sonication (ultrasound) and/or a LASER as the source of light and/or a light source in conjunction with a photo-catalyst, such as one comprising palladium. [0049] With respect to Product 4, proper substitution at positions R 5 through R 10 can lead to the release of benign, or even of beneficial compounds. By way of example and without limitation, the aromatic system can be chosen to be a fungicide, preservative agent, or insect repellant as is the case for the released aromatic compounds depicted in FIG. 4 . The list of potential “value added” aryl-unit containing products (Product 4) afforded by Compound 4 are numerous. Many common pesticides (including herbicides, insecticides, fungicides, rodenticides, and/or acaracides, by way of example), bee attractant, preservative and other agrichemical compounds have been identified that are potential “value added” side products (as Product 4) of Compound 4 concomitant with the release of 1-MCP or 1-TFMCP. Method 4: Release of 1-MCP and a Value Added Compound via Exposure of Analogues of tricyclo[3.2.2.0 2,4 ]nona-6,8-diene to Heat [0050] The representative parent compound for Method 4 which upon exposure to heat releases 1-MCP (as Product 1), and an Aromatic functionality containing by-product (as Product 5) may be illustrated by Compound 5 and its analogues identified above where R 1 or R 4 are comprised of a methyl group and all other R 1 through R 4 are protons. The representative parent compound for Method 4 which upon exposure to heat releases 1-TFMCP (as Product 1), and an Aromatic functionality containing by-product (as Product 5) may be illustrated by Compound 5 and its analogues identified above where R 1 or R 4 are comprised of a trifluoromethyl group and all other R 1 through R 4 are protons. Where Compound 5AA′ is used, and any one of R 5 , R 6 , R 7 , R 8 , R 7 ′, or R 8 ′ is comprised of a methyl ester group, and all other R 5 through R 8 ′ are hydrogens, the yielded product will contain (as Product 5AA′) a methylbenzoate (a common bee attractant). Sonication (ultrasound) can be used to increase rates. The general reaction of Compound 5 upon exposure to heat is the release of one equivalent each of Product 1 and Product 5. Furthermore, as outlined above each R, excepting R I through R 4 , a substituent as discussed for Compound 1, above. Increased rates may be obtained by using sonication (ultrasound). [0051] Akin to the Compound 4, and analogues thereof, R besides R 1 through R 4 , should be chosen to entail the release of a benign or beneficial compound containing an aromatic moiety as Product 5 (instead of benzene). Again, the list of potential “value-added” compounds is quite large. [0052] It will be understood that various changes can be made in the form details, arrangement, and proportions of the various parts without departing from the spirit and scope of the present invention.

Compounds and methods that release 1-methylcyclopropene, 1-trifluoromethylcyclopropene, and other substituted cyclopropenes are disclosed. The compounds and methods overcome present limitations for storage, transportation, and application of the cyclopropene containing compounds by using light, including sunlight, and/or heat as the primary release trigger. Additional products released include innocuous gases and value added aryl-group compounds.

BACKGROUND OF THE INVENTION The present invention relates to a new and improved construction of withdrawing carrier or taker-gripper for looms with removal of the filling thread or the like from stationary bobbins, the carrier being of the type comprising a hook having a pivotable or swingable clamping tongue. Taker-grippers or withdrawing carriers of this type are used at gripper looms. These taker-grippers serve to engage the filling thread which has been withdrawn by an inserting carrier or bringer-gripper from a stationary bobbin and introduced approximately to the center of the shed and to draw the thus engaged filling thread through the second half of the shed. After departure of the taker-gripper out of the shed the clamped filling thread is released. With a state-of-the-art taker-gripper of the previously mentioned type, as known for instance from the commonly assigned U.S. Pat. No. 4,062,382, granted Dec. 13, 1977, it is possible that, notwithstanding faultless functioning of the clamping tongue, the filling thread during its transport through the second half of the shed is suddenly released by the gripper, and thus, is not completely inserted into the shed. This malfunction appears to be attributable to vibrations of the taker-gripper during the insertion of the filling thread. These vibrations can be transmitted to the clamping tongue and can undesirably cause pivoting of the clamping tongue, and thus, premature release of the filling thread. SUMMARY OF THE INVENTION Therefore, with the foregoing in mind it is a primary object of the present invention to provide a new and improved construction of withdrawing carrier of the previously mentioned type which extensively eliminates the aforementioned drawbacks and shortcomings of the prior art carriers discussed above. Another and more specific object of the present invention aims at improving the heretofore known carriers or grippers in a manner such that malfunctions of the previously mentioned type can be positively avoided, so that the filling thread is no longer unintentionally released by the gripper. Yet a further significant object of the present invention aims at the provision of a new and improved construction of withdrawing carrier for the filling thread of gripper looms, which carrier is relatively simple in design, economical to manufacture, extremely reliable in operation, and incorporates mechanism for augmenting the clamping action exerted by the clamping tongue, to thereby beneficially avoid, or at the very least extensively minimize, the possibility of premature release of the filling thread during its insertion through the shed of the loom. Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the carrier of the present invention, which is of the type comprising a hook and a swingable or pivotable clamping tongue, contemplate the provision of an additional clamping element for the filling thread in order to augment the clamping action exerted by the clamping tongue upon the filling thread. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein: FIG. 1 is a top plan view of a withdrawing carrier or taker-gripper according to the invention; FIG. 2 is a view of the withdrawing carrier, looking in the direction of the arrow II of FIG. 1; FIG. 3 is a view of the withdrawing carrier, looking in the direction of the arrow III of FIG. 2; FIG. 4 is a fragmentary detail top plan view of the clamping tongue of the withdrawing carrier shown in FIG. 1; FIG. 5 is an enlarged sectional view, taken substantially along the line V--V of FIG. 2; FIGS. 6 and 7 are analogous sectional views, similar to that shown in FIG. 5, but portraying respective modified embodiments of the withdrawing carrier; and FIG. 8 is a fragmentary view, similar to the showing of FIG. 3, showing details of the variant embodiment portrayed in FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings, the withdrawing carrier or taker-gripper 1, illustrated by way of example in FIGS. 1 to 5, will be seen to be mounted on the front end of a flexible band 2 of a carrier or gripper type loom, this flexible band 2 serving for driving the withdrawing carrier or taker-gripper 1 in its back and forth motion during the operation of the loom, as is well known in this art. The withdrawing carrier 1 comprises a hollow gripper body or body member, generally indicated in FIG. 1 by reference character 1a, of rectangular cross-section. This hollow gripper body 1a comprises a base plate 3, a front side wall 4 which faces the cloth fell, a rear side wall 5 and a web or strap 6 or equivalent structure which interconnects both of the side walls 4 and 5. The rear side wall 5 and the web 6 extend towards the gripper or carrier tip and terminate at an essentially flat hook 7. Within the hollow body 1a, which is surrounded by the base plate 3, side walls 4 and 5 and web 6, there is arranged an elongate or lengthwise extending, flat and resilient clamping tongue 8. This clamping tongue 8 is mounted such that it can swing or pivot perpendicular to the plane of the hook 7, and specifically in such a manner that, in relation to the showing of FIG. 1, the free end of the clamping tongue 8 swings or rocks below the plane of the drawing of FIG. 1. The withdrawing carrier or taker-gripper 1, during operation of the loom, is inserted for instance from the left-hand side of the shed. The flexible band or tape 2 and the plane of the hook 7 are then dispositioned essentially parallel to the central plane of the warp threads (not shown). The hook 7 is open at the front side wall 4. Both of the outer edges or surfaces 10a and 11a of the hook arms 7a and 7b, respectively, terminate at the hook tip 9, whereas the inner edges or surfaces, designated by reference characters 10 and 11, of both hook arms 7a and 7b, respectively, limit the hook mouth 12. The end of the hook 7 is designated by reference character 13. The inner edges or surfaces 10 and 11 of both hook arms 7a and 7b are each provided with a respective stepped portion 14 and 15 (FIG. 5), and specifically, in such a manner that the hook mouth 12 is narrower at the upper side than at the lower side of the hook 7. Continuing, it will be seen that the clamping tongue 8 protrudes by means of its free end 16 into the hook mouth 12, and specifically into its wider portion 12a located at the underside of the hook 7. The rear lengthwise edge 16a (FIG. 4) of the clamping tongue end 16, and which faces away from the cloth fell, serves as a guide edge, while the front lengthwise edge, generally designated by reference character 16b in FIG. 4, together with the stepped or recessed portion 14 of the hook inner edge 10 forms a clamping gap 50 for a filling thread F. The free end 16 of the clamping tongue 8 is beveled or angled at its front longitudinal edge 16b and contains at such region a clamping surface 17 of larger slope for thicker threads or yarns and a clamping surface 18 of smaller slope for thinner threads or yarns. These two clamping surfaces 17 and 18 can smoothly merge into one another. Furthermore, the clamping tongue 8 has a substantially trapezoidal cross-section at the region of its end 16 and the inner edges 10 and 11 of the hook 7 are correspondingly wedgeshaped at the region of their stepped or recessed portions 14 and 15. In this way, there is beneficially realized a double wedging action at the clamping gap 50, by virtue of which the filling thread F, on the one hand, is always positively clamped and, on the other hand, upon release of the clamping action exerted by the clamping tongue 8 is also rapidly released. The clamping tongue 8 is preferably formed of one piece, for instance forged, and is threadably connected at its one end by screws 19 or equivalent fastening expedients to the base plate 3. At its underside or bottom the clamping tongue 8 is provided with a stiffening or reinforcement rib 20 extending in its lengthwise direction. Moreover, this clamping tongue 8 possesses such an initial tension or pre-bias that its end 16 is upwardly pressed against the stepped or recessed structure 14, 15 provided at the hook mouth 12. A clamping tongue of this type has been disclosed in detail in the aforementioned, commonly assigned U.S. Pat. No. 4,062,382, to which reference may be readily had and the disclosure of which is incorporated herein by reference. Now in order to release the clamping action it is necessary, following insertion of the filling thread F, to apply a downwardly acting force at the clamping tongue 8, so that the end 16 will swing or pivot downwards. For this purpose, the top surface of the clamping tongue 8 is provided with a substantially wedge-shaped ascending control surface 21 approximately at the intermediate region between the screws 19 and the hook mouth 12. Upon departure of the hook tip 9 and thus the filling thread F out of the shed, this control surface 21 comes into contact with a release element which is stationarily mounted at the loom, for instance a camming surface (not shown), and thus, such control surface 21 together with the clamping tongue 8 is downwardly pivoted or rocked. The amplitude of such pivoting or swinging motion is limited in downward direction by the base plate 3 of the withdrawing carrier or taker-gripper 1. During the weaving of heavy fabrics, it might happen that the pressure of the warp threads in the shed upon the control surface 21 is sufficient in order to downwardly pivot or swing the clamping tongue 8. This is prevented by the front side wall 4 of the withdrawing carrier 1 inasmuch as the upper edge 22 of such front side wall 4 is structured as a thread repelling or deflection edge which serves to space the warp threads from the control surface 21. A further disturbance possibility which can arise during weaving, and in fact has already arisen, is the unintentional release of the filling thread F by the withdrawing carrier 1 owing to vertical oscillations of the clamping tongue which are caused by impact of the withdrawing carrier or gripper 1 against its guide arrangement. This disturbance or malfunction possibility is beneficially eliminated in that, at the region of the clamping gap 50 there is provided an additional clamping element which augments or assists the clamping action of the clamping tongue 8. This additional clamping element, to be considered in greater detail shortly, is likewise resiliently structured as the clamping tongue 8 and can act either directly upon the filling thread F in that it additionally clamps the same, as shown in the embodiments of FIGS. 5 and 6, or else it can act upon the clamping tongue 8 and secure such against unintentional pivoting of this clamping tongue 8 out of the hook mouth 12, as shown with the embodiments of FIGS. 7 and 8. With the embodiment shown in FIGS. 1 to 5, the additional clamping element is formed by a clamping spring 24 or equivalent structure which is threadably connected for displacement in the lengthwise direction of the gripper at the front side wall 4 by means of the elongate holes 23 and coacting fixing screws or the like. This clamping spring 24, defining the additional clamping element, extends into the hook mouth 12, as best seen by referring for instance to FIG. 1. Furthermore, this clamping spring 24 is pre-biased or tensioned such that it presses against the hook inner edge 10 and is pivotable or swingable in the plane of the hook 7 and thus perpendicular to the pivot or swing plane of the clamping tongue 8. At the front side wall 4 there is inserted a guide pin 25 or equivalent structure which piercingly extends through a not particularly referenced bore of the clamping spring 24 and thus additionally guides such clamping spring 24. In the arrangement shown in FIG. 5 the clamping spring 24 is disposed in the hook mouth 12 above the clamping tongue 8 and presses against the hook inner edge 10 above the stepped or recessed portion 14. With the somewhat modified exemplary embodiment of FIG. 6, wherein there will be particularly highlighted the differences from the arrangement of FIG. 5, the clamping spring 24' extends through the hook mouth 12 over essentially its entire vertical extent. Due to this construction it is possible to dispense with the stepped portion 14 shown in the arrangement of FIG. 5, since now the filling thread F is clamped between the clamping spring 24' and the inner edge 10' and the clamping tongue 8 presses by means of its clamping surface 17 against the clamping spring 24' constituting the additional clamping element. With the further modified embodiment, illustrated in FIGS. 7 and 8, the clamping spring 24", again consituting the additional clamping element, is arranged below the clamping tongue 8 and like such clamping tongue is also pivotable or swingable in vertical direction. This clamping spring 24" presses from below against the clamping tongue 8 and thus secures such against any unintentional swinging out or pivoting in the downward direction. Here the clamping spring 24" is fixed, for instance screwed, to the lower edge of the front side wall 4, extends relatively narrowly up to the clamping gap, so that it does not hinder the insertion of the filling thread F, and finally, possesses at its front end a widened portion 24a by means of which it presses against the clamping tongue 8. Having now had the benefit of the description of the various proposed exemplary embodiments of withdrawing carrier there will now be considered its mode of operation, which is as follows: The withdrawing carrier or taker-gripper 1 is transported by its drive band 2 from the left-hand side of the loom up to approximately the center of the shed and at that location, at the region of the hook tip 9, comes against the filling thread F by means of the front outer edge or surface 10a of the hook 7. This filling thread F has been offered by a not particularly shown inserting carrier or bringer-gripper in a position where it extends essentially perpendicular to the plane of the hook 7. The withdrawing carrier or gripper 1 moves into the inserting carrier or bringer-gripper. The filling thread F, which is still fixedly retained by the inserting gripper, slides over the front outer edge 10a of the hook 7 and the hook end 13 in the direction of the clamping gap or slot 50. During the outward movement of the withdrawing carrier 1 out of the shed the filling thread F arrives at the clamping gap or slot 50 and, specifically, up to the region thereof which essentially corresponds to its thickness. At this point in time there is released in any conventional manner, as is known in this technology, the clamping action at the inserting carrier, and the filling thread F which has now been fixedly clamped by the withdrawing carrier 1, and specifically by the clamping tongue 8 and/or the clamping spring 24 or 24' is drawn by such withdrawing carrier 1 through the second half of the shed. After insertion of the filling thread has been completed, the clamping action upon the filling thread, exerted by the withdrawing carrier, is released in the already described manner. Due to the compactness of the withdrawing carrier or taker-gripper 1 it is particularly suitable for use with looms at which there are employed as the gripper drive flexible bands or tapes of the type shown in the figures of the drawings. But, of course, the withdrawing carrier 1 can also be employed on rigid insertion bars or the like. While there are shown and described present preferred embodiment of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. ACCORDINGLY,

A withdrawing carrier for looms with removal of the filling thread from stationary bobbins, the carrier having a hook and a pivotal clamping tongue. An additional clamping element is provided for augmenting the clamping action exerted by the clamping tongue upon the filling thread.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional application of U.S. application Ser. No. 10/893,182 filed Jul. 16, 2004, which claims benefit of U.S. Provisional Application No. 60/492,434 filed Aug. 4, 2003. The entire disclosures of the prior applications are hereby incorporated by reference. BACKGROUND OF THE INVENTION The present invention relates to an aromatic monomer-metal complex, an aromatic polymer-metal complex, which can be prepared from the monomer-metal complex, and an organic electronic device that contains a film of the polymer-metal complex. Organic electronic devices are found in a variety of electronic equipment. In such devices, an organic active layer is sandwiched between two electrical contact layers; the active layer emits light upon application of a voltage bias across the contact layers. Polymers containing pendant metal-complex groups constitute a class of polymers suitable for light emitting applications, particularly in active matrix driven polymeric LED displays. These polymers can be prepared, for example, by first polymerizing a monomer containing a ligand capable of complexing with a metal, then contacting the polymer with an organometallic complexing compound to insert the metal center into the polymer bound ligand. For example, in Macromolecules, Vol. 35, No. 19, 2002, Pei et al. describes a conjugated polymer with pendant bipyridyl groups directly coordinating with various Eu +3 α,β-diketones. Similarly, in WO 02/31896, pp 17-18, Periyasamy et al. describes lanthanide metal-complexed polymers prepared by either a one- or two-step synthetic route. In the one-step route, an ML n emitter is reacted with a polymer having metal-reactive functionality (X) to form a polymer with pendant —X-ML n-1 groups. In the two-step route, a polymer with pendant hydroxyethyl functionality is first condensed with a bipyridyl compound containing carboxylic acid functionality to form a polymer containing bipyridyl ester functionality (X-L′), which is then reacted with ML n to form a polymer with pendant X-L′-ML n-1 functionality. One of the problems with these metal complexed electroluminescent polymers is the incomplete reaction of pendant ligands with the metal complexing reagent. This inefficient coupling results in unpredictability of the properties of the final polymer due to the difficulty in controlling the degree of metal-ligand complexation. Accordingly, it would be advantageous to prepare a luminescent polymer with precisely controlled metal complexation. SUMMARY OF THE INVENTION The present invention addresses a need by providing in one aspect a halogenated aromatic monomer-metal complex compound comprising a halogenated aromatic monomer fragment and a metal complex fragment and represented by the following structure: where L is a bidentate ligand; M is Ir, Rh, or Os; Ar′ and Ar″ are aromatic moieties which may be the same or different with the proviso that at least one of Ar′ and Ar″ is heteroaromatic; and wherein R a and R b are each independently a monovalent substitutent or H, with the proviso that at least one of R a and R b contains a halogenated aromatic monomer fragment and a linking group that disrupts conjugation between the halogenated aromatic monomer fragment and the metal complex fragment. In a second aspect, the present invention is an electroluminescent polymer having a backbone comprising a) structural units of an aromatic monomer-metal complex having an aromatic fragment and a metal complex fragment, which structural units are represented by the following formula: where L is a bidentate ligand; M is Ir, Rh, or Os; Ar′ and Ar″ are aromatic moieties which may be the same or different with the proviso that at least one of Ar′ and Ar″ is heteroaromatic; and wherein R′ a and R′ b are substitutents or H, with the proviso that at least one of R′ a and R′ b contains an aromatic group that is part of the polymer backbone and a linking group that disrupts conjugation between the aromatic group and the metal complex fragment; and b) structural units of at least one aromatic comonomer, which polymer is characterized by being conjugated along a polymer backbone created by structural units of the aromatic monomer-metal complex and structural units of the at least one aromatic comonomer. In a third aspect, the present invention is an electronic device comprising a thin film of a luminescent polymer sandwiched between an anode and a cathode, which luminescent polymer has a backbone with a) structural units of an aromatic monomer-metal complex, which structural units are represented by the following formula: where L is a bidentate ligand; M is Ir, Rh, or Os; Ar′ and Ar″ are aromatic moieties which may be the same or different with the proviso that at least one of Ar′ and Ar″ is heteroaromatic; and wherein R′ a and R′ b are substitutents or H, with the proviso that at least one of R′ a and R′ b contains an aromatic group that is part of the polymer backbone and a linking group that disrupts conjugation between the aromatic group and the metal complex fragment; and b) structural units of at least one aromatic comonomer, which polymer is characterized by being conjugated along a polymer backbone created by structural units of the aromatic monomer-metal complex and structural units of the at least one aromatic comonomer. The present invention addresses a need in the art by providing a simple way of preparing a conjugated electroactive polymer with precisely controlled metal complexation. Moreover, the metal complex groups have electronic and/or luminescent properties that are minimally affected by the conjugated polymer backbone. DETAILED DESCRIPTION OF THE INVENTION The first aspect of the present invention is a composition comprising a halogenated aromatic monomer-metal complex having a halogenated aromatic monomer fragment and a metal complex fragment and represented by the following formula: where L is a bidentate ligand; M is Ir, Rh, or Os; Ar′ and Ar″ are aromatic moieties which may be the same or different with the proviso that at least one of Ar′ and Ar″ is heteroaromatic; and wherein R a and R b are each independently a monovalent substitutent or H, with the proviso that at least one of R a and R b contains a halogenated aromatic monomer fragment and a linking group that disrupts conjugation between the aromatic monomer fragment and the metal complex fragment. The halogenated aromatic monomer-metal complex of the present invention can be thought of as comprising a metal complex fragment and one or more halogenated aromatic monomer fragments as illustrated: R a is X m Ar-G- and R b is X n Ar-G-; each Ar is independently an aromatic group; each G is independently a divalent linking group that disrupts conjugation between Ar and Ar′-Ar″, preferably alkylene, O, S, carbonyl, SiR 2 , where R is a substituent, or oxyalkylene, more preferably methylene, oxymethylene, or O; each X is independently a halogen group, preferably, each X is chloro or bromo; the sum of m+n is a positive integer, preferably 1 or 2; more preferably 1; and the sum of o+p is a positive integer, preferably 1 or 2, more preferably 1. When o (or p) is 0, R a (or R b ) can be any substituent including H. Thus, it is most preferred that each Ar′-Ar″ ligand contain one monohalogenated aromatic substituent separated from Ar′-Ar″ by conjugation disrupting group. The ligand Ar′-Ar″ is attached at least one substituent that is a polymerizable aromatic monomer separated from the ligand by a divalent linking group. Examples of suitable substituted Ar′-Ar″ ligands include, but are not restricted to 2-phenylpyridines, 2-benzylpyridines, 2-(2-thienyl)pyridines, 2-(2-furanyl)pyridines, 2,2′-dipyridines, 2-benzo[b]thien-2-yl-pyridines, 2-phenylbenzothiazoles, 2-(1-naphthalenyl)benzothiazoles, 2-(1-anthracenyl)benzothiazoles, 2-phenylbenzoxazoles, 2-(1-naphthalenyl)benzoxazoles, 2-(1-anthracenyl)benzoxazoles, 2-(2-naphthalenyl)benzothiazoles, 2-(2-anthracenyl)benzothiazoles, 2-(2-naphthalenyl)benzoxazoles, 2-(2-anthracenyl)benzoxazoles, 2-(2-thienyl)benzothiazoles, 2-(2-furanyl)benzothiazoles, 2-(2-thienyl)benzoxazoles, 2-(2-furanyl)benzoxazoles, benzo[h]quinolines, 2-phenylquinolines, 2-(2-naphthalenyl)quinolines, 2-(2-anthracenyl)quinolines, 2-(1-naphthalenyl)quinolines, 2-(1-anthracenyl)quinolines, 2-phenylmethylpyridines, 2-phenoxypyridines, 2-phenylthiopyridines, phenyl-2-pyridinylmethanones, 2-ethenylpyridines, 2-benzenemethanimines, 2-(pyrrol-2-yl)pyridines, 2-(imidazol-2-yl)-pyridines, 2-phenyl-1H-imidazoles, and 2-phenylindoles. As used herein, “aromatic compounds” includes both aromatic and heteroaromatic compounds unless otherwise stated. Similarly, the term “aryl” is used herein to include both aryl and heteroaryl groups or compounds unless otherwise stated. The divalent linking group G contains a linking group or atom that disrupts conjugation, thereby inhibiting electron delocalization between the aromatic monomer fragment and the metal complex fragment. This disruption of conjugation between the fragments results in a similar disruption between the complex and the conjugated polymer backbone formed from the aromatic monomer fragment. Disruption of conjugation is often desirable to preserve the light emission properties of the metal complex in a polymer formed from the aromatic monomer-metal complex. Such properties could be disadvantageously perturbed if electrons are delocalized between the conjugated polymer backbone and the complex. The linking group is preferably a substituted or unsubstituted non-conjugated linear, branched, or cyclohydrocarbylene group or a divalent heteroatom or combinations thereof. Examples of linking groups include, alone or in combination, alkylene or cycloalkyl groups such as methylene, ethylene, propylene, isopropylene, butylene, isobutylene, t-butylene, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups; and heteroatoms such as oxygen and sulfur atoms and R—Si—R, carbonyl, and amine groups, except for triaryl amines. Preferred linking groups include an oxygen atom and methylene and oxymethylene groups. As used herein, “oxymethylene” refers to —OCH 2 — or —CH 2 O— groups. General Procedure for Preparation of a Bis(Monohalogenated Aromatic) Monomer-Metal Complex A halogenated aromatic monomer-metal complex containing a bis(monohalogenated aromatic) fragment attached to a metal complex through a linking group can be prepared by a 4-step process, as shown: G is as previously defined and is preferably O, methylene, or oxymethylene; Ar, Ar′, and Ar″ are each independently aromatic moieties with the proviso that at least one of Ar′ and Ar″ is heteroaromatic. Preferably, Ar is a non-heteroaromatic moiety including a benzene, a naphthalene, or an anthracene moiety, more preferably a benzene moiety. Preferably, Ar′ and Ar″ are each independently selected from the group consisting of benzene, pyridine, thiophene, and fluorene moieties that are complexed with the metal so as to form a 5-membered ring. More preferably one of Ar′ and Ar″ is a benzene moiety and the other of a Ar′ and Ar″ is pyridine moiety. X is halo, X′ and X″ are each independently halogen, boronate, —ZnCl, —ZnBr, —MgCl, MgBr, or —Sn(C 1-10 -alkyl) 3 , with the proviso that one of X′ and X″ is halogen and the other of X′ and X″ is boronate, —ZnCl, —ZnBr, —MgCl, MgBr, or —Sn(C 1-10 -alkyl) 3 ; X′″ is halogen, hydroxy, or alkoxy, preferably chloro, bromo, methoxy, or ethoxy, more preferably chloro or bromo. Where X′″ is halogen, the addition of the hydroxide or alkoxide base is not necessary; where X′″ is hydroxy or alkoxy, the addition of a hydroxide or alkoxide base is preferred. L is a bidentate ligand which can be the same as or different from Ar′-Ar″. Other examples of L include a diamine, including ethylene diamine, N,N,N′,N′-tetramethyl ethylene diamine, propylene diamine, N,N,N′,N′-tetramethyl propylene diamine, cis- and trans-diaminocyclohexane, and cis- and trans-N,N,N′,N′-tetramethyl diaminocyclohexane; an imine, including 2[(1-phenylimino)ethyl]pyridine, 2[(1-(2-methylphenylimino)ethyl]pyridine, 2[(1-(2,6-isopropylphenylimino)ethyl]pyridine, 2[(1-(methylimino)ethyl]pyridine, 2[(1-(ethylimino)methyl]pyridine, 2[(1-(ethylimino)ethyl]pyridine, 2[(1-(isopropylimino)ethyl]pyridine, and 2[(1-(t-butylimino)ethyl]pyridine; a dimine, including 1,2-bis(methylimino)ethane, 1,2-bis(ethylimino)ethane, 1,2-bis(isopropylimino)ethane, 1,2-bis(t-butylimino)ethane, 2,3-bis(methylimino)butane, 2,3-bis(ethylimino)butane, 2,3-bis(isopropylimino)butane, 2,3-bis(t-butylimino)butane, 1,2-bis(phenylimino)ethane, 1,2-bis(2-methylphenylimino)ethane, 1,2-bis(2,6-diisopropylphenylimino)ethane, 1,2-bis(2,6-di-t-butylphenylimino)ethane, 2,3-bis(phenylimino)butane, 2,3-bis(2-methylphenylimino)butane, 2,3-bis(2,6-diisopropylphenylimino)butane, and 2,3-bis(2,6-di-t-butylphenylimino)butane; a heterocyclic compound containing two nitrogen atoms, including 2,2′-bypyridine, and o-phenanthroline; a diphosphine, including bis-(diphenylphosphino)methane, bis-(diphenylphosphino)ethane, bis-(diphenylphosphino)propane, bis-(dimethylphosphino)methane, bis-(dimethylphosphino)ethane, bis-(dimethylphosphino)propane, bis-(diethylphosphino)methane, bis-(diethylphosphino)ethane, bis-(diethylphosphino)propane, bis-(di-t-butylphosphino)methane, bis-(di-t-butylphosphino)ethane, and bis-(di-t-butylphosphino)propane; a 1,3-diketonate (β-diketonate) prepared from a 1,3-diketone (β-diketone), including acetyl acetone, benzoyl acetone, 1,5-diphenylacetyl acetone, dibenzoyl methane, and bis(1,1,1-trifluoroacetyl)methane; a 3-ketonate prepared from a 3-keto ester, including acetoacetic acid ethyl ester; a carboxylate prepared from an aminocarboxylic acid, including pyridine-2-carboxylate, 8-hydroquinolinate, quinoline-2-carboxylate, glycine, dimethyl glycine, alanine, and dimethylaminoalanine; a salicyliminates prepared from a salicylimine, including methyl salicylimine, ethyl salicylimine, and phenyl salicylimine; a dialcoholate prepared from a dialcohol, including ethylene glycol and 1,3-propylene glycol; a dithiolate prepared from a dithiol, including 1,2-ethylene dithiolate and 1,3-propylene dithiolate. Preferably, L is a β-diketonate, pyridine-2-carboxylate, a salicyliminate, or a derivative of 8-hydroquinoline or quinoline-2-carboxylic acid. Conjugated Luminescent Polymers Containing Metal Complexes The halogenated aromatic monomer-metal complex is a precursor for a metal-complexed conjugated luminescent polymer, which can be a homopolymer, a copolymer, a terpolymer, etc., and which can be prepared by any of a number of means, For example, the polymer can be prepared by a Suzuki coupling reaction, described in U.S. Pat. No. 6,169,163 (the '163 patent), column 41, lines 50-67 to column 42, lines 1-24, which description is incorporated herein by reference. In the present case, the Suzuki coupling reaction can be carried out by reacting, in the presence of a catalyst, preferably a Pd/triphenylphosphine catalyst such as tetrakis(triphenylphosphine)palladium(0), the halogenated aromatic monomer-metal complex, preferably the bis(monohalogenated aromatic) complex, with a diboronated aromatic compound. The aromatic group of the co-monomer—which form structural units of the resultant polymer—may be the same as or different from, preferably different from, the aromatic group associated with the halogenated aromatic monomer-metal complex. It is also possible, and sometimes preferable, to prepare a polymer having structural units of more than two monomers by including in the reaction mixture a variety of halogenated and boronated co-monomers along with the halogenated aromatic monomer-metal complex. Polymerization can also be carried out by coupling one or more dihalogenated aromatic monomer-metal complexes with one or more dihalogenated aromatic compounds in the presence of a nickel salt, as described in the '163 patent, column 11, lines 9-34, which description is incorporated herein by reference. The aromatic co-monomers that can be used to couple with the halogenated aromatic monomer-metal complex is nearly endless but a representative list includes, 1,4-diXbenzenes, 1,3-diXbenzenes, 1,2-diXbenzenes 4,4′-diXbiphenyls, 1,4-diXnaphthalenes, 2,6-diXnaphthalenes, 2,5-diXfurans, 2,5-diXthiophenes, 5,5-diX-2,2′-bithiophenes, 9,10-diXanthracenes, 4,7-diX-2,1,3-benzothiadiazoles, diX triarylamines including N,N-di(4-Xphenyl)anilines, N,N-di(4-Xphenyl)-p-tolylamines, and N-diXphenyl-N-phenylanilines, 3,6-diX-N-substituted carbazoles, 2,7-diX-N-substituted carbazoles, 3,6-diX-dibenzosiloles, 2,7-diX-dibenzosiloles, N-substituted-3,7-diXphenothiazines, N-substituted-3,7-diXphenoxazines, diX-N,N,N′,N′-tetraaryl-1,4-diaminobenzenes, diX-N,N,N′,N′-tetraarylbenzidines, diXarylsilanes, and 2,7-diX-9,9-disubstituted fluorenes, including fluorenes in which the 9,9-substituents combine to form a ring structure, and combinations thereof, where each X is independently a halogen or a boronate, preferably bromo or chloro or boronate, more preferably bromo or boronate. As used herein, “boronate” refers to an aromatic fragment or compound that is substituted with a borane group, a boronic acid ester group, or a boronic acid group. The resultant polymer has a backbone having structural units of a) an aromatic group which is also attached to a linking group that disrupts conjugation between the aromatic group and the metal complex fragment; and b) an aromatic comonomer, which forms a conjugated system with the aromatic group. The term “structural units” is used herein to refer to the remnant of the monomer after polymerization. A structural unit of the aromatic group that is attached to the metal complex through a linking group is represented by the following structure: where L, M, Ar′, and Ar″ are as previously defined, and at least one of R′ a and R′ b , preferably only one of R′ a and R′ b , contains an aromatic group that is part of the polymer backbone, preferably a phenyl group, a naphthalenyl group, or an anthracenyl group, more preferably a phenyl group; and a linking group, G, that disrupts conjugation between the aromatic group and the metal complex fragment. The other of R′ a and R′ b is preferably a monovalent substituent, including H. Thus, where Ar is phenyl and R′ b is H, the following structural unit is formed: Similarly, a structural unit of a benzene-containing comonomer that is incorporated into the polymer backbone through the 1,4-positions is a 1,4-phenylene group; a structural unit of a 9,9-disubstituted fluorene-containing comonomer that is incorporated into the polymer backbone through the 2,7-positions is a 9,9-disubstituted fluorene-2,7-diyl group, where each R is a substituent, as illustrated: Accordingly, the structural units corresponding to the above listed co-monomers are 1,4-phenylenes, 1,3-phenylenes, 1,2-phenylenes, 4,4′-biphenylenes, naphthalene-1,4-diyls, naphthalene-2,6-diyl, furan-2,5-diyls, thiophene-2,5-diyls, 2,2′-bithiophene-5,5-diyls, anthracenes-9,10-diyls, 2,1,3-benzothiadiazoles-4,7-diyls, N-substituted carbazole-3,6-diyls, N-substituted carbazole-2,7-diyls, N-substituted-phenothiazine-3,7-diyls, N-substituted-phenoxazines-3,7-diyls, triarylamine-diyls including triphenylamine-4,4′-diyls, diphenyl-p-tolylamine-4,4′-diyls, and N,N-diphenylaniline-3,5-diyls, dibenzosilole-3,6-diyls, dibenzosilole-2,7-diyls, N,N,N′,N′-tetraaryl-1,4-diaminobenzene-diyls, N,N,N′,N′-tetraarylbenzidine-diyls, arylsilane-diyls, and 9,9-disubstituted fluorenes-2,7-diyls. It is to be understood that the polymer, copolymer, etc. is not limited by the manner in which it is made. The resultant polymer has a conjugated backbone with metal complexation that can be precisely controlled because preferably at least 90%, more preferably at least 95%, and most preferably 100% of the structural units of the aromatic monomer-metal complex contain a metal complex that is incorporated within the polymer backbone. Moreover, the metal complex is insulated from the conjugated polymer backbone due to the absence of direct delocalization between the ligand and the polymer backbone, which insulation preserves the luminescent properties of the metal complex. The terms “conjugated polymer” and “conjugated polymer backbone” are used to mean that the polymer backbone has electrons that are delocalized throughout at least two adjacent structural units, preferably at least five adjacent structural units, more preferably at least ten adjacent structural units. Preferably, the ratio of structural units of halogenated aromatic monomer-metal complex to structural units of the comonomer is preferably at least 0.01:99.99, more preferably at least 0.1:99.9, and most preferably at least 1:99; and preferably not greater than 20:80, more preferably not greater than 10:90. The polymer of the present invention preferably has a weight average molecular weight M w of at least 5000 Daltons, more preferably at least 10,000 Daltons, more preferably at least 50,000 Daltons, and most preferably at least 100,000 Daltons; and preferably less than 2,000,000 Daltons. M w is determined using gel permeation chromatography against polystyrene standards. The polymer of the present invention can be combined with one or more other polymers to make a blend. Examples of suitable blending polymers include homo- or co-polymers (including terpolymers or higher) of polyacrylates, polymethacrylates, polystyrenes, polyesters, polyimides, polyvinylenes, polycarbonates, polyvinyl ethers and esters, fluoropolymers, polycarbazoles, polyarylene vinylenes, polyarylenes, polythiophenes, polyfurans, polypyrroles, polypyridines, polyfluorenes, and combinations thereof. The polymer or blend of the present invention can be combined with a sufficient amount of one or more solvents (hereinafter “solvent”) to make a solution which is useful, for example, as an ink. The amount of solvent varies depending upon the solvent itself and the application, but is generally used at a concentration of at least 80 weight percent, more preferably at least 90 weight percent, and most preferably at least 95 weight percent, based on the weight of the luminescent polymer, the optional additives or modifiers, and the solvent. Examples of suitable solvents for the polymer include benzene; mono-, di- and trialkylbenzenes including C 1-12 -alkyl benzenes, xylenes, mesitylene, cyclohexylbenzene, and diethylbenzene; furans including tetrahydrofuran and 2,3-benzofuran; 1,2,3,4-tetrahydronaphthalene; cumene; decalin; durene; chloroform; limonene; dioxane; alkoxybenzenes including anisole, and methyl anisoles; alkyl benzoates including methyl benzoate; biphenyls including isopropyl biphenyl; pyrrolidinones including cyclohexylpyrrolidinone; imidazoles including dimethylimidazolinone; and fluorinated solvents; and combinations thereof. More preferred solvents include C 1-8 -alkyl benzenes, cyclohexylbenzene, xylenes, mesitylene, 1,2,3,4-tetrahydronaphthalene, methyl benzoate, isopropyl biphenyl, and anisole, and combinations thereof. In a typical application, the ink formulation can be deposited on a substrate such as indium-tin-oxide (ITO) glass having a hole transporting material disposed thereon. The solvent is then evaporated, whereupon the ink forms a thin film of the luminescent polymer. The film is used as an active layer in an organic light-emitting diode (OLED) device, which can be used to make a display such as a self-emissive flat panel display. The film is also useful in other electronic devices including light sources, photovoltaic cells, and field effect transistor devices. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention. EXAMPLE 1 Preparation of Iridium (III) bis{2-[4′-(4″-bromophenoxy)phenyl]pyridinato-N,C 2 ′}(acetylacetonate A. Preparation of 2-(4′-Phenoxy)phenylpyridine 4-Phenoxyphenylboronic acid (10.7 g, 0.05 mol) and 2-bromopyridine (11.58 g, 0.075 mol) were dissolved in 250 mL of THF followed by addition of 2M NaCO 3 (60 mL) and tetrakis(triphenylphosphine)palladium (0) (0.29 g). The reaction mixture was boiled at reflux overnight and then transferred into a separation funnel to remove the aqueous layer. The organic layer was removed in vacuo and the residue was eluted through a silica gel column, first with 1:1 chloroform and hexane mixture and then with pure chloroform to afford a pale yellow oil. HPLC showed a purity of 99.5%. GCMS: M + =247. B. Preparation of 2-[4′-(4″-Bromophenoxy)phenyl]pyridine A solution of N-bromosuccinimide (NBS, 3.95 g, 22.2 mmol) in DMF (10 mL) was added to a solution of 2-(4′-Phenoxy)phenylpyridine (5.8 g, 23.4 mmol) in DMF (100 mL) at room temperature. The reaction mixture was stirred at 80° C. for 1 h. HPLC showed about 40% of the starting material was converted. Additional NBS (1.55 g) was added and the reaction continued at 80° C. overnight. HPLC indicated a conversion of 55%. Additional NBS (5 g) was added and the reaction was continued at 80° C. for 1 h. HPLC showed complete conversion of the starting material. After being cooled to room temperature, the reaction mixture was poured into water (300 mL) with stirring whereupon NaOH solution (15 mL of 50% (w/w)) was added into the mixture. The mixture was stirred at room temperature for 2 h and was then filtered to collect the solid. The solid was washed with water and was re-crystallized from ethanol to provide 5.5 g of the titled compound in white crystals. HPLC showed a purity of 98.6%. GCMS: M + =327. C. Preparation of Iridium (III) bis{2-[4′-(4″-bromophenoxy)phenyl]pyridinato-N,C 2 ′} μ-chloro-bridged dimer Iridium (III) chloride (% Ir=54.11, 1.5 g, 4.25 mmol) and 2-[4′-(4″-bromophenoxy)phenyl]pyridine (3.5 g) were dispersed in 2-ethoxyetanol (30 mL) at room temperature. The mixture was boiled at reflux under nitrogen for 20 h, at which time, a yellow solid precipitated from solution. Methanol (100 mL) was added to the reaction mixture to complete the precipitation. The solid was collected by filtration and was washed with methanol, 1N HCl, and ethanol successively and then was dried in vacuo at 40° C. to provide 3.27 g of yellow powder. D. Preparation of Iridium (III) bis{2-[4′-(4″-bromophenoxy)phenyl]pyridinato-N,C 2 ′}(acetylacetonate) Iridium (III) bis{2-[4′-(4″-bromophenoxy)phenyl]pyridinato-N,C 2 ′} μ-chloro-bridged dimer (1.05 g, 0.6 mmol) and sodium carbonate (1.0 g) were dispersed in 2-ethoxyethanol (60 mL). The mixture was degassed with nitrogen at room temperature for 15 min, whereupon 2,4-pentanedione (0.132 g, 1.32 mmol) was added together with 2-ethoxyethanol (20 mL). The mixture was refluxed for 1 h. TLC showed no dimer starting material and the main product was found to be a green emissive material. After being cooled to room temperature, water (100 mL) was added to precipitate the product. The yellow solid was collected by filtration and dried in vacuo at 40° C. overnight. The crude product was re-dissolved in methylene chloride and purified on a silica gel column eluted by methylene chloride to give 0.48 g of yellow powder, purtiy of 99.5% by HPLC: EXAMPLE 2 Preparation of a Co-polymer Containing Iridium (III) bis[2-(4′-phenoxyphenyl)pyridinato-N,C 2 ′](acetylacetonate) Tetrakis(triphenylphosphine)palladium(0) (5 mg) and 2M aqueous sodium carbonate solution (11 mL) were added under nitrogen to a stirred mixture of 9,9-di(1-octyl)fluorene-2,7-diboronic acid ethylene glycol ester (2.149 g, 4.04 mmol), 2,7-dibromo-9,9-di(1-octyl)fluorene (1.647 g, 3.00 mmol), 3,7-dibromo-N-(4-n-butyl)-phenyl-phenoxazine (0.190 g, 0.40 mmol), N,N′-(di(bromophenyl)-N,N′-di(9,9-dibutyl)fluorene-1,4-phenylenediamine (0.390 g, 0.40 mmol), iridium (III) bis{2-[4′-(4″-bromophenoxy)phenyl]pyridinato-N,C 2 ′}(acetylacetonate) (0.188 g, 0.20 mmol), and Aliquat 336 (0.75 g) phase transfer catalyst in toluene (50 mL). The reaction mixture was stirred at 101° C. under nitrogen for 16 h. Then, 9,9-di(1-octyl)fluorene-2,7-diboronic acid ethylene glycol ester (20 mg) was added and the polymerization was continued under the same conditions for another 3 h. Bromobenzene (0.15 g dissolved in 10 mL of toluene) was then added under the same reaction conditions for 2 h. Phenylboronic acid (0.4 g) and tetrakis(triphenylphosphine)palladium(0) (3 mg dissolved in 10 mL of toluene) was added under the same reaction conditions for 4 h. The mixture was allowed to cool to about 50° C., the aqueous layer removed, and the organic layer washed with water. The resultant polymer solution was then poured into methanol (1.5 L) with stirring to precipitate pale yellow polymer fibers. These fibers were collected by filtration, washed with methanol, and dried in vacuo at 50° C. overnight. The polymer was re-dissolved in toluene and the solution passed through a column packed with layers of celite and silica gel. The combined eluates were concentrated to about 100 mL, then poured into methanol (1.5 L) with stirring. The polymer fibers were collected and dried in vacuo at 50° C. overnight. The polymer was re-dissolved in toluene and re-precipitated in methanol. After further filtration and drying, 2.26 g of pale yellow fibers were obtained. The weight average molecular weight (M w ) of the polymer was measured by gel permeation chromatography (GPC) against the polystyrene standards as 121,000 with a polydispersity index (M w /M n ) of 3.78. EXAMPLE 3 Iridium (III) bis[2-(4′-phenoxyphenyl)pyridinato-N,C 2 ′](acetylacetonate) Containing a Fluorene copolymer II The procedure described in Example 2 was followed except that N,N-diphenyl-3,5-dibromoaniline (0.3248 g, 0.80 mmol) was used instead of dibromo-N-(4-n-butyl)-phenyl-phenoxazine and N,N′-(di(bromophenyl)-N,N-di(9,9-dibutyl)fluorene-1,4-phenylenediamine (0.390 g, 0.40 mmol); the copolymer II was prepared in the yield of 2.13 g. EXAMPLE 4 Light-Emitting Devices of a Metal Complex-Containing Polymer A thin film of poly(ethylenedioxythiophene)/polystyrenesulfonic acid (commercially available from H.C. Starck and BAYTRON™ P conducting polyer) was spin-coated on a ITO (indium tin oxide)-coated glass substrate, at a thickness of 80 nm. Then, a film of the metal complex-containing polymer described in Example 3 was spin-coated on the PEDOT film at a thickness of 80 nm from a solution in xylenes. After drying, a thin layer (3 nm) of LiF was deposited on the top of the polymer layer by thermal evaporation, followed by the deposition of a calcium cathode (10-nm thick). An additional aluminum layer was applied by evaporation to cover the calcium cathode. By applying a bias (ITO wired positively) on the resultant device, bluish green light emission was obtained. The electroluminescent spectrum recorded at 200 cd/m 2 corresponds to the chromaticity coordinates of (x=0.240, y=0.270) in the CIE 1931 diagram. The brightness of the emission reached 200 cd/m 2 at about 13 V with the luminance efficiency of 0.08 cd/A.

A halogenated aromatic monomer-metal complex useful for preparing a polymer for electronic devices such as a light-emitting diode (LED) device is described. The aromatic monomer-metal complex is designed to include a linking group that disrupts conjugation, thereby advantageously reducing or preventing electron delocalization between the aromatic monomer fragment and the metal complex fragment. Disruption of conjugation is often desirable to preserve the phosphorescent emission properties of the metal complex in a polymer formed from the aromatic monomer-metal complex. The resultant conjugated electroluminescent polymer has precisely controlled metal complexation and electronic properties that are substantially or completely independent of those of the polymer backbone.

BACKGROUND OF THE INVENTION The present invention relates to copolyetheresteramides, derived from caprolactam and/or ε-aminocaproic acid and other polyamide-forming monomers as amide-forming components and equimolecular quantities of saturated aliphatic linear dicarboxylic acids, having 6 to 13 C-atoms, and poly(alkylene oxide diols) as etherester-forming components. European Patent Application No. A 00 17 112 (Bayer) discloses copolyetheresteramides, containing 50 to 80% by weight of ε-caprolactam and further polyamide-forming monomers and equimolecular quantities of saturated aliphatic linear dicarboxylic acids and poly(alkylene oxide diols), incorporated by polycondensation. These copolyetheresteramides are said to find application as high quality raw materials for thermoplastic adhesives, the field of the shoe industry being the only particular intended use indicated. These copolyetheresteramides are unsuitable as hot-melt adhesives for textiles, because they are difficult to process into powders and, in particular, do not yield satisfactory adhesion values, particularly after dry cleaning and laundry treatment, which is an absolute pre-requisite for useful hot-melt adhesives for textiles. Similarly, West German Patent Application No. A 2 523 991 discloses copolyetheresteramides, which, however, do not contain any caprolactam and/or ε-aminocaproic acid incorporated by condensation. The copolyetheresteramides described therein can be used for moulding and extrusion processing. There is no reference to the use as hot-melt adhesives, particularly for textiles. The copolyetheresteramides, described in this literature reference, are not suitable as hot-melt adhesives for textiles, because they do not yield adequate adhesion values at the hot-sealing temperatures to be applied in the glueing of textiles. West German Patent Application No. A 29 49 064 discloses copolyetheresteramides, which are to be used as hot-melt adhesives for textiles. These, however, contain lauric lactam as the essential amide-forming component. The disadvantage of these products is that lauric lactam is a relatively inaccessible and, therefore, expensive polyamide-forming substance and that the preparation of the copolyamides has to be carried out at high pressures and temperatures. The copolyetheresteramides of West German Patent Application No. A 29 49 064 have the advantage, by comparison with the known polyamides, employed as hot-melt adhesives for textiles--compare, inter alia, West German Patent Application No. C 1 253 449)--that they produce a softer handle in the glued textiles. SUMMARY OF THE INVENTION The present invention is based on the problem of discovering hot-melt adhesives for glueing textiles, which produce a softer handle, by comparison with the polyamide hot-melt adhesives known from West German Patent Application No. C 1 253 449, but can be produced easily from readily available monomers. It has been believed so far that this problem can only be solved if substantial quantities of lauric lactam are used as polyamide-forming substance--compare West German Patent Application No. A 29 49 064. It has now been surprisingly found that this is not the case and that the above problem is solved by means of copolyetheresteramides, produced with caprolactam. Therefore the above problem is solved by means of copolyetheresteramides derived from caprolactam and/or ε-amino-caproic acid and other polyamide-forming monomers as amide-forming component and equimolecular quantities of saturated aliphatic linear dicarboxylic acids, having 6 to 13 C-atoms, and poly(alkylene oxide diols) as polyetherester-forming components, characterised in that they contain, incorporated by polycondensation, 20 to 40% by weight of caprolactam and/or ε-aminocaproic acid, 10 to 30% by weight of an equimolecular mixture of adipic acid and primary aliphatic and/or cycloaliphatic C 6 to C 25 diamines, 10 to 30% by weight of an equimolecular mixture of azelaic and/or sebacic acid and primary aliphatic and/or cycloaliphatic C 6 to C 25 diamines and 20 to 40% by weight of an equimolecular mixture of decanedicarboxylic and/or brassylic acid and primary aliphatic and/or cycloaliphatic C 6 to C 25 diamines, always related to the total quantity of the polyamide-forming components, and that, for 65 to 90% by weight of the total quantity of the polyamide-forming components, there are 10 to 35% by weight of the equimolecular quantities of saturated aliphatic linear dicarboxylic acids, having 6 to 13 C-atoms, and poly(alkylene oxide diols) as polyetherester-forming component. Preferably, the quantities of the above-mentioned polyamide-forming components, in the above sequence, are the following: 25 to 35% by weight of 6, 15 to 25% by weight of 6.6, 15 to 25% by weight of 6.9 and/or 6.10 and 25 to 35% by weight of 6.12 and/or 6.13. The above abbreviations "6" denote the polyamide-forming components in the internationally customary manner of abbreviation. They indicate that the component has the corresponding number of C-atoms. If two numbers are separated by a point, the first number denotes the diamine component and the second number the dicarboxylc acid component. The copolyetheresteramides are prepared by polycondensation of the above-mentioned starting compounds. A further subject of the invention is the use of the above copolyetheresteramides for heat-sealing textiles or, respectively, a process for heat-sealing textiles in a manner that is known per se, in which, however, the copolyetheresteramides described above are used as hot-melt adhesives. Although the copolyetheresteramides described do not contain any lauric lactam, incorporated by condensation, they surprisingly possess very great adhesive strength, even after dry cleaning and after laundering operations, which is surprising to those skilled in the art. The glued textiles have a pleasant soft handle. The glued zones are elastic. DETAILED DESCRIPTION OF THE INVENTION Preferably, the equimolecular mixture of azelaic acid and diamine is used as the third component. Decanedicarboxylic acid is preferred as the carboxylic acid of the fourth component. Hexamethylene diamine is preferred among the diamines. It can be employed exclusively. It is also possible, however, to employ mixtures of diamines, in which case hexamethylene diamine forms preferably a proportion of at least 50% by weight, with special preference for at least 70% by weight, related to the total quantity of diamines. Other diamines that may be mentioned are isophorone diamine (IPD), 1,3-bis (aminomethyl)cyclohexane, nonamethylene diamine, 3-methyl-pentamethylene diamine and dodecane diamine. Two-nucleus diamines can also be employed, such as 4,4'-diamino-3,3'-dimethyl-dicyclohexylmethane, 4,4'-diamino-3,3', 5,5'-tetramethyl-dicyclohexylmethane, 4,4'-diamino-dicyclohexylpropane and, preferably, 4,4'-diamino-dicyclohexylmethane and diamino-dicyclohexylmethane isomer mixtures, at least 75% of which consist of the 4,4'-isomer. Evidently, mixtures of the diamines mentioned are also suitable. Particular properties of the end-products may be influenced by the choice of diamines, as is also known already in the copolyamide field. The products disclosed in the above-mentioned publications can be employed as the poly(alkylene oxide diols). Poly(alkylene oxide diols), having a molecular weight of between 400 and 2000, are preferred. Preferably, the lower limit for the molecular weight is 500. The upper limit is preferably 1200. These poly(alkylene oxide diols) are preferred that contain between the oxygen atoms alkylene groups having two or four C-atoms. Linear chains are preferred. Polyethylene glycol is particularly preferred. Similarly, the saturated aliphatic linear dicarboxylic acids employed, having 6 to 13 C-atoms, are the dicarboxylic acids disclosed in the literature references, mentioned at the beginning. Brassylic acid and, particularly, decanedicarboxylic acid are preferred. The copolyetheresteramides melt within the range of about 90° to 160° C., determined by the DSC method (Differential Scanning Calorimetry method). The melting point lies preferably below 150° C. Low-melting products are particularly suitable for glueing heat-sensitive textiles. Appropriately, the copolyetheresteramides have a solution viscosity η relative of 1.3 to 1.75. The lower limit is preferably 1.45. The upper limit is appropriately 1.65. The solution viscosity is measured in a 0.5% solution in m-cresol at 20° C., (Ostwald viscometer). The melt viscosity at 180° C. lies appropriately within the range of 400 to 5000 dPa.s. The lower limit is preferably about 800 dPa.s. The upper limit is preferably about 4000 dPa.s, measured with the rotation viscometer RV 2, plate and cone (P/C) system. The copolyetheresteramides are prepared in the manner known to those skilled in the art from the publications mentioned at the beginning. Appropriately, the copolyamide-forming components and the saturated aliphatic linear dicarboxylic acids, having 6 to 13 C-atoms, are first reacted with each other, with formation of a copolyamide having terminal carboxyl groups. The reaction takes place appropriately at temperatures of about 180° to 300° C., preferably about 200° to 260° C. Since lauric lactam is not included in the formulation, the reaction can be carried out at normal pressure. Slightly elevated pressures can, however, be applied for accelerating the reaction. Polycondensation is effected, in the usual way, by addition of small quantities of water. In accordance with the state of the art, the reaction is carried out with exclusion of air, that is to say under an inert gas atmosphere. Preparation of the polyamide takes place within about 2 to 5 hours, water being dissociated, preferably during about 2.5 to 3.5 hours. Subsequently, the poly(alkylene oxide diol) is added and a customary catalyst and the polycondensation is carried out at reduced pressure, appropriately within the range of about 100 mbar to 1 mbar. The lowest possible pressure is advantageous, because the reaction time is shortened. The temperatures for after-condensation lie within the range of about 180° to 300° C., preferably about 200° to 260° C. The after-condensation is carried out at the pressures mentioned for about 0.5 to 5 hours, preferably for about 1 to 3 hours, the particular time period depending on the remaining conditions applied (temperature, pressure, catalyst) and the desired degree of polymerisation, that is to say the desired viscosity. Theoretically, the process can also be worked at pressures above 100 mbar, but, in that case, the reaction period is lengthened considerably, which is undesirable, as a rule, since decomposition phenomena may occur. The catalysts employed are those known for this reaction according to the state of the art. Dialkyl zirconates are preferred, the alkyl groups being able to be branched or linear and containing 1 to 24 C-atoms. Tetraalkyl orthotitanates can also be employed. Alkyl group having 4 C-atoms are preferred, especially n-butyl compounds. The quantity of catalyst lies within the known range of about 0.01 to 5% by weight, related to the weight of the reaction mixture. Preferably, the quantity of catalyst is below about 1% by weight. Production can also be effected in such a way that all the starting products are first heated to the above-mentioned temperatures of about 180° to 300° C., preferably about 200° to 260° C., for a period of about 2 to 5 hours, with dissociation of water, preferably for about 2.5 to 3.5 hours. Subsequently, after-condensation is carried out under reduced pressure within the range indicated above and at the temperatures indicated above for the above-mentioned period, until the desired degree of polymerisation is attained. The copolyetheresteramides according to the invention may also contain, in addition, small quantities of other polyamide-forming substances than those mentioned above, incorporated by condensation. For reasons of easy availability and satisfactory reproducibility of preparation and production of products of constant properties, however, it is generally not indicated to add yet further components. With the aid of the copolyetheresteramides according to the invention, textiles of various kinds can be glued together. Examples of these are natural materials and/or synthetic materials, such as wool, silk, cotton or polyesters, polyamides and the like. Hides and the like can also be glued on as substrates. A copolyetheresteramide according to the invention, preferably in powder form, is placed between the surfaces that are to be glued together. Naturally, the copolyamide may also be employed in the form of films, threads, short-cut threads or fleeces. It is also possible to prepare dispersions from powders in a manner that is known per se and to use them for heat-sealing. If powders or dispersions are employed, they are applied to one of the substrates to be glued by means of known machines and slightly sintered by application of elevated temperatures, so that the hot-melt adhesive adheres firmly to the substrate. The latter can may be stored and dispatched as such and be glued to the desired other substrate later on. The substrates may, however, be glued together immediately. Glueing is effected with application of elevated temperature and pressure. The pressing temperature depends, above all, on the heat-sensitivity of the substrate, but has to be sufficiently high for melting and glueing to take place. On cooling to room temperature, solidification occurs, with joining of the glued substrates. The preparation of the powders is effected in the same way as is known with polyamide hot-melt adhesives. The granulate first obtained is milled in the cold and classified. As in the case of polyamide hot-melt adhesives for textiles, the range of particle size is appropriately 60 to 200 μm for the so-called powder point process, appropriately 200 to 500 μm for the powder dusting process and, for the paste point process (dispersions), the range of particle size is employed below about 80 μm. Customary additives may be added to the powder, such as metal soaps, for example calcium stearate or zinc stearate, optical brightening agents, stabilisers, such as sterically hindered phenols or other additives as are customary for polyamide hot-melt adhesives. The dispersions can have the composition customary for polyamide hot-melt adhesives, that is to say anti-settling agents, dispersing agents and the like. An advantage of the copolyetheresteramides of the invention is that the additional use of plasticisers is not necessary. If desired, however, plasticisers can also be added, particularly to dispersions. Suitable plasticisers are, for example, sulphonic acid derivatives, as described in U.S. patent application No. A 4,093,492, columns 3 and 4. Appropriately, the copolyetheresteramides have a melt index MFI at 150° C. at 2.16 kp according to DIN 53 735 of about 5 to 40 g/10 minutes. The upper limit is appropriately about 30, the lower limit appropriately about 7. EXAMPLE 1 The following components are weighed into a closed autoclave, provided with an agitator and a column: 6.30 kg caprolactam 2.30 kg adipic acid 2.60 kg azelaic acid 5.90 kg decanedicarboxylic acid and 5.62 kg hexamethylene diamine 100% (employed as an 80% aqueous solution). After flushing the reactor with nitrogen, the closed system was heated to 230° C., with stirring. During this time, a pressure of 6 bar was established, which is being maintained by pressure release, if necessary, for two hours. After this 2-hour pre-condensation, the pressure is slowly reduced to normal pressure by opening a valve. Subsequently, the residual water was distilled off within 1 hour. After addition of 7.30 kg polytetramethylene glycol (molecular weight 1000) (PTMG) and 0.07 kg di-n-butyl zirconate, the product was heated to 250° C. in a gentle nitrogen stream within 30 minutes. Subsequently, the product was submitted to after-condensation at a pressure of 1 mbar within 35 minutes. The polycondensate obtained was spun through an orifice nozzle into a water bath and granulated. The physical values measured are compiled in Table 1. The granulate was milled in a commercial cold milling unit to powder having the following particle size distribution: less than 63 μm=28.0% by weight less than 80 μm=34.4% by weight less than 100 μm=41.2% by weight less than 150 μm=58.4% by weight less than 200 μm=72.4% by weight less than 300 μm=90.8% by weight less than 400 μm=98.4% by weight less than 500 μm=99.6% by weight After separation of the individual fractions, the particle size range of 80 to 200 μm was applied to a commercial cotton interlining fabric by means of a commercial powder point unit. The coated interlining fabric was iron-pressed together with a commercial surface fabric (55% polyester, 45% cotton) under pressure and at elevated temperature. The glued parts were washed 5 times at 60° C. with a commercial detergent. Further parts were subjected to 5 runs of dry cleaning. The untreated, washed and cleaned samples were tested for resistance to separation according to DIN 54 310. The results obtained are set out in Table 1. EXAMPLE 2 Following the method described in Example 1, a polyetheresteramide was prepared from the following raw materials: 4.20 kg caprolactam 1.56 kg adipic acid 1.73 kg azelaic acid 4.82 kg decanedicarboxylic acid 3.72 kg hexamethylene diamine 100% (employed as an 80% aqueous solution) 3.97 kg polyethylene glycol (molecular weight 450) (PEG) and 0.07 kg di-n-butyl zirconate. In this case, after-condensation took about 60 minutes. The polycondensate obtained was milled, as indicated in Example 1, and gave the following particle size distribution: less than 63 μm=24.4% by weight less than 80 μm=31.6% by weight less than 100 μm=38.8% by weight less than 150 μm=54.8% by weight less than 200 μm=68.4% by weight less than 300 μm=88.0% by weight less than 400 μm=97.6% by weight less than 500 μm=99.6% by weight The values determined in the subsequent textile performance testing of the 80 to 200 μm fraction are set out in Table 1. It possesses particularly good steam resistance. EXAMPLE 3 The following components were weighed onto an autoclave, provided with a column and an agitator: 6.30 kg caprolactam 2.30 kg adipic acid 2.60 kg azelaic acid 5.90 kg decanedicarboxylic acid and 5.62 kg hexamethylene diamine 100% (employed as an 80% aqueous solution). After flushing the reactor with nitrogen, the system was heated to 230° C., with stirring, and pre-condensation was carried out for about 3 hours at this temperature, the reactor being flushed with a gentle nitrogen stream after about 2 hours. Subsequently, after addition of 7.30 kg polytetramethylene glycol (molecular weight 1000) (PTMG) and 0.07 kg di-n-butyl zirconate, the temperature was raised to 250° C. within about 45 minutes. After-condensation was carried out for about 45 minutes at this temperature and at a pressure of 1 mbar. The polycondensate obtained has the same properties as that obtained in Example 1. TABLE 1__________________________________________________________________________ Example 1 Example 2__________________________________________________________________________Composition in 30% 6 30% 6% by weight 20% 6.6 20% 6.6 20% 6.9 20% 6.9 30% 6.12 30% 6.12 70% PA 70% PA 30% PTMG 12 30% PEG 12Melting range 135-137 131-136(optical) °C.η rel of 0.5% 1.38 1.66solution in m-cresol @ 20° C.Melt viscosity at 1200 3900180° C. in dPa.s;Rotoviscometer RV2,system P/CMFI at 150° C. 23 9in g/10 min. at2.16 kpDIN 53 735Textile performance NTS 5 × 60° 5 × DT NTS 5 × 60° 5 × DTtestsIroning machineplate time groove140° 15 sec. 133° 13 13 15 14 13 13.5150° 15 sec. 143° 13 13 13 18 16.5 17.5160° 15 sec. 152° 13 13 15 21 21 22.5weight applied 17 g ± 2 g 17 g ± 2 gg/m.sup.2Pressing pressure 0.35 0.35bar__________________________________________________________________________ NTS = normal tearing strength in N/5 cm 5 × 60° = tearing strength after 5 washings at 60° C. in N/5 cm 5 × DT = tearing strength after dry cleaning for 5 sec. in N/5 cm The composition is understood as follows: 6=caprolactam; 6.6=hexamethylene diamine/adipic acid; 6.9=hexamethylene diamine/azelaic acid; 6.12=hexamethylene diamine/decanedicarboxylic acid PA=polyamide

Copolyetheresteramides containing, incorporated by condensation, 20 to 40% by weight of caprolactam and/or ε-aminocaproic acid, 10 to 30% by weight of an equimolecular mixture of adipic acid and primary aliphatic and/or cycloaliphatic C 6 to C 25 diamines, 10 to 30% by weight of an equimolecular mixture of azelaic or sebacic acid and primary aliphatic and/or cycloaliphatic C 6 to C 25 diamines and 20 to 40% by weight of an equimolecular mixture of decanedicarboxylic and/or brassylic acid and primary aliphatic and/or cycloaliphatic C 6 to C 25 diamines, always related to the total quantity of the polyamide-forming components, and in which, for 65 to 90% by weight of the total quantity of the polyamide-forming components, there are 10 to 35% by weight of the equimolecular quantities of saturated aliphatic linear dicarboxylic acids, having 6 to 13 C-atoms, and poly(alkylene oxide diols) as polyetherester-forming component, and a process for their preparation. The copolyetheresteramides are used for the heat-sealing of textiles.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority under 35 U.S.C. § 119 of a provisional application Ser. No. 61/041,727 filed Apr. 2, 2008, which application is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to lighting and more particularly to energy efficient lighting. BACKGROUND OF THE INVENTION [0003] Persistence of vision is well known. Also well known is the use of illumination devices to overcome flicker by use of persistence of vision such as commonly associated with movie projectors. It is also known that on cathode ray tube (CRT) displays, increasing the refresh rate also decreases perceived flickering. Therefore, intermittent light sources are well known to provide persistence of vision. [0004] In the field of vision sciences, Talbot and Plateau (1834 and 1835) were able to determine the rules that govern the perceived brightness of intermittent light sources flickered at rates above the Critical Flicker Frequency (CFF). Their results, now known as the “Talbot Plateau Law”, showed that: The perceived brightness of a “fused” intermittent light source is the same as it would be if the same total stimulation were distributed uniformly throughout the whole cycle. [0006] Thus, the Talbot-Plateau Law states that the brightness of intermittent light is equal to the brightness of steady light with the same time-averaged luminance. For the Talbot-Plateau Law to apply, the intermittent light must illuminate at a rate beyond the Critical Flicker Frequency (CFF), which is the frequency at which flicker induced by intermittent illumination disappears. BRIEF SUMMARY OF THE INVENTION [0007] Increased “brightness” can be achieved by implementing intermittent illumination at temporal frequencies above the CFF. That is, intermittent, but perceptually fused lights will appear brighter than equal total energy continuous lights. This is contrary to the “Talbot Plateau law” and, since increased brightness above the CFF is achieved, then it is occurring due to other physiological phenomena not currently known, recognized and/or understood. [0008] According to one aspect of the present invention, a method for providing lighting includes sweeping an array of light sources on and sweeping the array of light sources off. The array of light sources being swept on and off at a frequency substantially higher than a critical flicker frequency to enhance perceived brightness. [0009] According to another aspect of the present invention, an apparatus is provided. The apparatus includes a plurality of light sources organized in a matrix and an intelligent control electrically connected to the plurality of light sources, wherein the intelligent control being adapted to sweep the light sources on and sweep the light sources off at a frequency substantially higher than a critical flicker frequency to provide enhanced perceived brightness. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 is a pictorial representation of one embodiment of the present invention. [0011] FIG. 2A is a view of a bank of LEDs at different points in time with scanning of LEDs to increase perceived brightness of the LEDs. [0012] FIG. 2B is a view of the bank of LEDs at different points in time with scanning of the LEDS to increase perceived brightness of the LEDs. [0013] FIG. 3 illustrates a bank of LEDs which is constantly on and a bank of LEDs which is sweep on. [0014] FIG. 4 illustrates a block diagram of a circuit for controlling a bank of LEDs. [0015] FIG. 5 illustrates examples of energy efficient lighting provided with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0016] The present invention relates to providing for improving lighting efficiency by sweeping an array of light sources at a frequency sufficient to increase the perception of brightness. In contradiction to the Talbot-Plateau Law, the present invention provides for increasing perceived brightness at rates above the Critical Flicker Frequency. The present invention provides for numerous possible applications, including enhancing the perceived brightness of lighting or providing the same level of perceived brightness with less energy than would be required to have lighting in a continuously on state. [0017] FIG. 1 illustrates a block diagram of one example of a test setup. An observer 2 may compare perceived brightness of a control light source 8 with a test light source 6 . The test light source 6 may be rotated on a platen 4 at different frequencies to determine the frequency at which the test light source 6 appears to have the same or greater brightness as the control light source 8 . [0018] FIG. 2A is a view of a bank of LEDs at different points in time with scanning of LEDs to increase perceived brightness of the LEDs. The same bank of LEDs is shown 12 different times to indicate the state of the LEDs at different points in time. The bank of LEDs is a bank or matrix of 12×6 LEDs, the size of which is merely provided for illustration purposes. The present invention contemplates any size of bank of LEDs. The bank of LEDs is shown at 12 different points in time during scanning of the LEDs across the bank to increase perceived brightness. There are rows 12 , 14 , 16 and columns 18 , 20 , 22 , 24 . In operation, a single line of LEDs is switched on at each interval in time to provide the effect of the bank of LEDs being continuously on. Although a single vertical line is shown, the present invention also contemplates that a single horizontal line may be used instead. In addition, the present invention contemplates that instead of scanning a single line of LEDS, multiple lines of LEDS may be turned on at the same time. [0019] FIG. 2B illustrates another embodiment of the present invention, where lines of LEDs remain on as they are swept across. The sweep may be reversed after the progression is complete, so that each vertical line of LEDs is turned off. [0020] FIG. 3 illustrates a bank of LEDs which is constantly on and a bank of LEDs which is swept on as perceived by a person. Where the frequency of the sweeping is sufficient the present inventor postulates that the perceived brightness of the bank of LEDs which is swept on may be equal to or greater than the perceived brightness of the bank of LEDs which is constantly on. This allows for the possibility of a gain in efficiency. That is to say, to achieve the same perceived brightness, the bank of LEDs need not be constantly on. [0021] FIG. 4 illustrates a block diagram of a circuit for controlling a bank of LEDs. As shown in FIG. 4 , an intelligent control 34 is electrically connected to a light source 32 which is configured to be swept on to increase perceived brightness. The light source 32 may be a matrix of LEDs or other types of light sources. The light source 32 is also connected to a power source 36 . [0022] FIG. 5 illustrates examples of energy efficient lighting provided with the present invention. One example is a street light 40 . The street light 40 includes a plurality of LEDs. The present invention contemplates that there may be other advantages from the use of swept illumination. For example, there may be reduced heating of light sources, or possibly increased life of the light sources. [0023] Another example is a flashlight 42 so as may be operated by battery power. The present invention contemplates that by sweeping light sources of the flashlight on, reduced power is needed to operate the flashlight thereby extending battery life of the device. [0024] These are merely a few of many examples of devices in which the present invention may provide a means of increasing energy efficiency. Other examples include the backlighting associated with liquid crystal displays as may be used on any number of electronic devices, including battery operated devices, such as, televisions, notebook computers, cellular phones, and personal entertainment devices such as MP3 players and video games. [0025] It is important to recognize that the present invention relates to an observed effect which is inconsistent with the Talbot-Plateau Law and different from mere persistence of vision. In particular, the present invention relates not merely to timing the turning on and off of light sources to achieve persistence of vision, but rather the timing of the turning on and off of light sources in order to enhance perceived brightness. The frequency necessary to enhance brightness is greater than the frequency needed to obtain persistence of vision. [0026] In an initial testing, 20 subjects were subjected to five measurements to assess relative perceived brightness between a light source at a brightness and a mechanically swept illumination. The mean of the sample of 20 subjects is highly significantly different (P<0.01) from 1.0 (no efficiency gains), indicating a statistically significant difference in efficiency for these 20 subjects. The average measured efficiency gain was 35 percent, and it ranged from 68 percent to 10 percent in this sample. It is to be appreciated that different individuals may be more or less perceptive of perceived brightness. [0000] Subject Mean Data  1 1.564  2 1.465  3 1.311  4 1.377  5 1.169  6 1.446  7 1.396  8 1.571  9 1.297 10 1.09 11 1.261 12 1.101 13 1.307 14 1.266 15 1.235 16 1.292 17 1.293 18 1.683 19 1.627 20 1.2 Sample mean 1.34755 Sample SD 0.16753271 [0027] The above data supports that enhanced brightness is perceived for swept illumination. The present invention provides for extending the mechanical implementation to an electronic implementation where LEDs are used as the light source. LEDs, and especially OLEDs, are generally recognized as providing efficiencies in lighting and can be readily controlled through electronics. [0028] Lighting intensity of LEDs is typically controlled by means such as increasing or decreasing current to the LEDs or else varying the current to the LEDs through pulse width modulation. Of course, such means provide for controlling lighting intensity within a range of brightness. The present invention provides for extending the range of perceived brightness, through a control system which sweeps the lighting at a frequency which is greater than the flicker frequency and sufficient to provide an increase in perceived brightness. [0029] Increasing perceived brightness may have one of a number of advantages depending upon the particular context in which it is used. First, light sources having a particular maximum brightness may have their perceived brightness increased beyond the maximum brightness. An appropriate control system may be used to retrofit or accessorize existing lighting application. Alternatively, the idea of perceived brightness may be considered when a lighting system is first designed to provide additional design alternatives. [0030] Thus, for example, lower cost light sources or more energy efficient light sources may be used. [0031] A further advantage of the energy efficiency may be achieved by the present invention because increased perceived brightness is achieved without increasing current to the lighting. Thus, the same perceived brightness can be obtained with less energy. [0032] The present invention contemplates numerous variations. This includes variations in the type of light source, including LED, incandescent, fluorescent, gas tube, or otherwise. The present invention contemplates variations in the manner in which the light sources are swept including mechanically or electronically. The present invention contemplates variations in the frequency of the sweeping providing the frequency is above the CFF and provides an enhanced perceived brightness effect. The present invention contemplates numerous variations in the specific application of the present invention, including to street lights, flash lights, LCD back lighting, and other applications. These and other variations, options, and alternatives are within the spirit and scope of the invention.

A method for providing lighting includes sweeping an array of light sources on and sweeping the array of light sources off. The array of light sources being swept on and off at a frequency substantially higher than a critical flicker frequency to enhance perceived brightness. An apparatus includes a plurality of light sources organized in a matrix and an intelligent control electrically connected to the plurality of light sources, wherein the intelligent control being adapted to sweep the light sources on and sweep the light sources off at a frequency substantially higher than a critical flicker frequency to provide enhanced perceived brightness.

TECHNICAL FIELD This invention relates to mixing apparatus, and has particular though not exclusive application to such apparatus for mixing liquids in relatively large containers, for example paints in intermediate bulk containers (IBC). BACKGROUND It is often necessary, prior to application or use, to mix the contents of large containers, in particular paint containers, to condition the paint for smooth and effective application. Heretofore, such mixing has been achieved in a variety of ways all of which suffer from various disadvantages. Impellers such as propellers comprising a plurality of spiral blades on a rotating shaft are commonly used. However, removal of the propeller after mixing invariably results in paint dripping from the propeller onto the outside of the container. Furthermore, the use of a propeller in anything other than a full container can result in considerable splashing of paint within and without the container, as well as undesirable entrainment of air into the paint by way of the central vortex created by the rotating propeller. Impellers are conventionally inserted through the top of a container to effect mixing, and, as mentioned above, can create problems if the container is only partially full. It has been proposed to achieve mixing by means of a unit attached to the bottom of a container and reacting with the contents of the lower regions of the container to create mass movement throughout the volume of the container which is effective even if the container is other than full. More particularly the unit includes a disc extending transversely of the lower regions of the container and provided with a central aperture surrounded by a plurality a circumferentially spaced apertures adjacent the periphery of the disc. A diaphragm below the disc is alternately moved upwards and downwards relative to the disc, the configuration of the apertures in the disc being such that, on upward movement of the diaphragm liquid is preferentially forced upwardly through the central aperture, and, on downward movement of the diaphragm, liquid is preferentially drawn downwardly through the peripheral apertures. Thus a swirling motion is created within the container which serves to mix the contents thereof. Such equipment, although non-intrusive, is complex and expensive, the mixing effect being very dependent upon the frequency of movement of the diaphragm, and is only suited to cylindrical containers. An alternative to the above equipment utilises a static funnel from which radiate a plurality of circumferentially spaced jet outlets, an air-operated double diaphragm pump creating mass movement of the liquid towards and away from the funnel. On movement of the liquid towards the funnel, the liquid is preferentially forced through the outlets to create jets of liquid within the lower regions of the container, and, on movement of the liquid away from the funnel, liquid is drawn down through the centre of the funnel, the overall system being such as to create a swirling motion within the body of liquid. Such a static jet mixer has been found to create closed cells within the body of liquid which remain unmixed and in which there is considerable heat build-up. Overall, mixing is unsatisfactory. SUMMARY OF THE INVENTION It would be desirable to be able to provide mixing apparatus which overcame the problems of the prior art, and in particular which ensured effective mixing of the full volume of contained liquid in an economic and cost effective manner. According to the present invention there is provided, for a liquid container, mixing apparatus comprising a hollow sleeve member for location in the lower regions of the container, a plurality of circumferentially spaced outlets being provided in the upper regions of the sleeve member, and pump means for creating a reciprocating flow of liquid applied to the lower regions of the sleeve member, characterised by, in the flow path of liquid from the pump means to the sleeve member, a transducer mechanism co-operating with the sleeve member and subjected to the reciprocating flow of liquid such as to rotate the sleeve member about its central longitudinal axis in dependence upon said reciprocating flow. It will be appreciated that, with such an arrangement, and as a result of the rotation of the sleeve member, which is typically through 15° for each pulse of liquid, the jets of liquid emanating from the outlets are each directed in continuously changing directions within the container, thereby ensuring thorough mixing of the liquid and avoiding the establishment of any substantially static regions of non-agitation within the liquid. In one embodiment of the invention, the pump means comprise a double acting diaphragm pump, the reciprocating movement of the diaphragm creating a mass movement of liquid into and out of the container. Preferably the transducer mechanism comprises a ratchet wheel secured to, to be rotatable with, the sleeve member, and one or more pawls adapted to engage the ratchet wheel and linearly movable by, in the direction of movement of, the reciprocating liquid. Conveniently there are two pawls mounted on a carrier and engaging diametrically opposite teeth of the ratchet wheel, the reciprocating movement of the liquid resulting in reciprocating movement of the carrier and attached pawls, each such movement of the carrier resulting in consequential stepped rotation of the sleeve member, each step being in the same direction of rotation. Preferably there are two diametrically opposed outlets from the upper regions of the sleeve member, each outlet being directed substantially radially from the sleeve member. The sleeve member and associated transducer mechanism may be located wholly within the lower regions of the associated container to provide a non-intrusive mixing system. Alternatively, the sleeve member may extend through an aperture in the container to locate the outlets therefrom within the lower regions of the container, the lower regions of the sleeve member and the transducer mechanism being external of the container to provide an intrusive mixing system. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic vertical section through mixing apparatus according to the invention in a container; FIG. 2 a shows the apparatus of FIG. 1 to a larger scale; FIG. 2 b is a plan view of the ratchet wheel, pawls and carrier of FIG. 2 a; FIG. 2 c is an end view of the carrier of FIGS. 2 a and 2 b; FIG. 3 is a diagrammatic vertical section through an alternative mixing apparatus according to the invention in a container; FIG. 4 shows the apparatus of FIG. 3 to a larger scale; and FIGS. 5 and 6 show, schematically and respectively, a non-intrusive and an intrusive mixing apparatus according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, there is shown a container 2 , typically an intermediate bulk container for holding paint, in the bottom wall 4 of which is mounted mixing apparatus according to the invention and generally referenced 6 . The mixing apparatus 6 comprises an outer cylindrical housing 8 secured through the bottom wall 4 of the container in sealed relationship therewith, and a hollow sleeve 10 coaxially within the housing 8 and rotatable relative thereto about its central longitudinal axis on a bearing 12 . An inlet 14 in the lower regions of the sleeve 10 feeds into the hollow interior thereof from the annular volume between the housing 8 and the sleeve 10 , while a pair of diametrically opposed outlets 16 are formed in the sidewalls of the sleeve 10 adjacent the upper regions thereof, the outlets 16 being defined by substantially radially extending nozzles 18 . A circular one-way valve mechanism or flow restrictor 20 is mounted within the sleeve 10 above the inlet 14 such as to permit upward flow through the sleeve but to prevent downward flow therethrough. An annular one-way valve or flow restrictor 22 is mounted in the annular volume between the housing 8 and the sleeve 10 adjacent the upper regions of the housing 8 to permit downward flow as indicated by arrows 22 ′ through this annular volume but to prevent upward flow therethrough. An annular ratchet wheel 24 is secured around the lower regions of, to be rotatable with, the sleeve 10 , the ratchet wheel carrying a plurality of external teeth 26 . A discharge pipe 28 feeds from the lower regions of the housing 8 , a pawl mechanism indicated generally at 30 being slidably mounted in the pipe 28 . The mechanism 30 comprises an annular disc 32 extending transversely of the pipe 28 to be guided thereby, a yoke 34 extending from the disc 32 longitudinally of the pipe 28 the opposed arms of which each carry at the free ends thereof a pawl 36 . The pawls 36 co-operate with the teeth 26 of the ratchet wheel 24 as best seen in FIG. 2 b and such that, on either forward or rearward movement of the mechanism 30 relative to the sleeve 10 , the ratchet wheel 24 , and therefore the sleeve 10 , is rotated in a clockwise direction as viewed in FIG. 2 b. Connected to the end of the discharge pipe 28 is one chamber of a double acting diaphragm pump schematically illustrated at 38 the piston assembly 40 of which is reciprocal between the two extreme positions shown in full lines and dotted lines in FIG. 2 a , the overall displacement of the assembly being indicated by the arrow ‘D’. An isolating valve 42 is provided in the discharge pipe 28 between the mechanism 30 and the pump 38 which is selectively operable to connect the pump 28 into the discharge pipe 28 . The described apparatus operates as follows. With the container 2 holding liquid to be mixed, and with the isolating valve 42 open, the pump 38 is actuated to reciprocate the piston assembly 40 . This creates a reciprocating flow in the discharge pipe 28 as indicated by arrow ‘F’, the effects of which are applied to the mechanism 30 and to the lower regions of the container 2 . More particularly, and as the pump 38 pulses liquid towards the container 2 , said liquid flows through the centre of the disc 32 , through the inlet 14 as indicated by arrow ‘I’, through the one-way valve 20 and out of the sleeve 10 through the outlets 16 /nozzles 18 as pressurised jets of liquid as indicated by arrows ‘J’. The one-way valve 22 prevents upward flow of liquid from the annular space between the housing 8 and the sleeve 10 into the container 2 . At the same time, the flow created by the pump 38 impinges upon the disc 32 to move the mechanism 30 to the left as viewed in FIGS. 2 a and 2 b , whereby one of the pawls 36 engages an associated tooth 26 on the wheel 24 to rotate the wheel and attached sleeve 10 in a clockwise direction as viewed in FIG. 2 b , while the other pawl 36 rides over an opposite associated tooth 26 . On return movement of the piston 40 , a reverse flow is created in the discharge pipe 28 and is transmitted to the mechanism 30 and the liquid in the container 2 . More particularly, liquid then flows from the container 2 into the annular space between the housing 8 and the sleeve 10 and through the one-way valve 22 as indicated by arrows 22 ′, and then into the discharge pipe 28 as indicated by arrow ‘P’. Flow from the hollow sleeve 10 into the discharge pipe 28 is prevented by the one-way valve 20 . This reverse flow moves the disc 32 , and therefore the mechanism 30 , to the right as viewed in FIG. 2 a whereby the other pawl 36 engages an associated tooth 26 of the wheel 24 to further rotate the wheel 24 and attached sleeve 10 in a clockwise direction as viewed in FIG. 2 b , the one pawl 36 riding over an opposite associated tooth 26 . Thus it will be appreciated that the pump 38 creates a constantly pulsating flow of liquid in the discharge pipe 28 , the energy of this flow being used to rotate the sleeve 10 by way of the mechanism 30 and at the same time to create pulses or jets of liquid emanating from the nozzles 18 . The jets are directed into the body of liquid as seen in FIG. 5 and serve to create a mixing flow as indicated by the arrows in that Figure. The pump 38 is typically operated at a frequency of 60 pulses per minute, with the sleeve 10 being rotated through typically 15° for each pulse of the pump. The constantly rotating sleeve 10 , and the consequential constantly changing positions of the nozzles 18 within the container 2 ensure extremely thorough mixing of the contents of the container 2 is achieved. Depending upon the application, the nozzles 18 may be directed upwardly and or downwardly of the horizontal. Once mixing is completed, the isolating valve 42 is closed and the pump 38 is removed from the pipe 28 to permit discharge of the contents of the container 2 . Alternatively, a T-junction may be provided in the pipe 28 to enable discharge without removal of the pump 38 as shown in FIG. 6 . FIGS. 1 and 2 illustrate an intrusive mixing system in which the mixing head of the apparatus 6 extends through a wall of the container 2 . FIGS. 3 and 4 illustrate what can be termed a non-intrusive system in which the mixing head of the apparatus 6 is totally housed within the container 2 . Referring to FIGS. 3 and 4, there is shown an alternative mixing apparatus in which components equivalent to those of FIGS. 1 and 2 are similarly referenced. The fundamental operation of the embodiment of FIGS. 3 and 4 is exactly the same as that of the embodiment of FIGS. 1 and 2, the only differences being in the position of the one way valve 22 and the flow path of liquid from the container into the discharge pipe 28 . The valve 22 or flow restrictor is located at the lower end of the housing 8 such that, on return movement of the piston assembly 40 of the pump 38 —ie. to the right as viewed in FIG. 4 —liquid flows through the valve 22 into the annular space between the housing 8 and the sleeve 10 as indicated by the arrow ‘S’ and into the discharge pipe 28 to move the mechanism 30 to the right. Thus there is provided mixing apparatus which is capable of thoroughly mixing large volumes of liquid in an efficient and effective manner. Although primarily developed for mixing coating materials such as paint, the apparatus can be used to mix a variety of substances such as pharmaceuticals, speciality chemicals, foodstuffs, mixtures requiring gaseous blankets and any substance that requires isolation from the surrounding environment. The mixing apparatus can be readily mounted on standard IBC's using simple tools, the system being such as to enable users to mix without compromising product integrity or resorting to specialised containers. Alternatively, and as illustrated in FIGS. 3 and 4, the mixing apparatus can be mounted within the lower regions of a container and retained in position by co-operation with the internal wall of the discharge pipe as it exits the container. In all cases, the pneumatic drive to the pump provides a reciprocating backwards and forwards motion within the liquid in the discharge pipe the energy from which is used to rotate the outlet nozzles such as to create extensive agitation of the liquid within the container and throughout the volume of said liquid. The frequency of the pump, and the degree of rotation of the sleeve per pulse of liquid can be chosen to suit particular requirements depending upon the product and the application. Clearly the precise construction of the apparatus can vary from that described and illustrated without departing from the scope of the invention. In particular the transducer mechanism to convert the flow energy of the liquid into rotation of the jets may be other than the pawlratchet mechanism detailed above, the reciprocating flow within the discharge pipe may be created other than by a double diaphragm pump, and there may be more than two jets per sleeve. Other modifications and variations will be apparent to those skilled in the art.

Apparatus for mixing liquid in a container, comprises a hollow sleeve member for location in the lower regions of the container, a plurality of circumferentially spaced outlets being provided in the upper regions of the sleeve member, pump means for creating a reciprocating flow of liquid applied to the lower regions of the sleeve member, and in the flow path of liquid from the pump means to the sleeve member, a transducer mechanism cooperating with the sleeve member and subjected to the reciprocating flow of liquid such as to rotate the sleeve member about its central longitudinal axis in dependence upon said reciprocating flow.

[0001] This application claims the benefit of U.S. Provisional Application No. 60/359,568 filed Feb. 25, 2002. BACKGROUND [0002] 1. Field of Invention [0003] The present invention pertains to shunt tubes used in subsurface well completions, and particularly to shunt tubes having multiple entrances. [0004] 2. Related Art [0005] Conduits providing alternate or secondary pathways for fluid flow are commonly used in well completions. The alternate pathways allow fluid to flow past and emerge beyond a blockage in a primary passageway. In prior art embodiments, the single entrance to an alternate pathway conduit could be covered, blocked, or otherwise become inaccessible to the fluid, thereby preventing the alternate pathway conduit from performing its intended function. Such blockage could occur, for example, when the conduit happened to be positioned on the bottom wall of a horizontal bore. [0006] Alternatively, if low viscosity fluids are used in an alpha beta wave pack, or should pumping fail, the conduit may become blocked. Therefore, there is a continuing need for improved entrance mechanisms to provide more reliable access to the alternate pathway conduits. SUMMARY [0007] The present invention provides for multiple pathways by which fluid can enter one or more alternate pathway conduits. Entrance tubes can be arranged such that their spacing prevents all of them from being simultaneously obstructed, covered, or otherwise blocked. [0008] Advantages and other features of the invention will become apparent from the following description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWING [0009] [0009]FIG. 1 is a schematic diagram of a portion of a completion assembly constructed in accordance with the present invention. [0010] [0010]FIG. 2 is a partially cutaway schematic diagram of an alternative embodiment of a completion assembly constructed in accordance with the present invention. [0011] [0011]FIG. 3 is a perspective view of the completion assembly of FIG. 2. DETAILED DESCRIPTION [0012] [0012]FIG. 1 shows a portion of a completion assembly 10 used in a well. A shunt tube 12 having a central passageway 14 is mounted on base pipe 16 . Only one shunt tube 12 is shown, but there may be more than one. Base pipe 16 may be slotted or perforated base pipe or production tubing. Entrance tubes 18 are also mounted on base pipe 16 . Entrance tubes 18 are azimuthally spaced around the circumference of base pipe 16 and connect at their lower ends to. shunt tube 12 . Those connections could be made using jumper tubes or other connectors known in the art. Each entrance tube 18 has a passageway 20 in fluid communication with central passageway 14 to accommodate fluid flow through entrance tubes 18 and shunt tube 12 . [0013] In the embodiment of FIG. 1, entrance tubes 18 are joined at a manifold 22 . Entrance tubes 18 may, however, join shunt tube 12 in various places along the length of shunt tube 12 , without relation to the junction of shunt tube 12 and other entrance tubes 18 . Entrance tubes 18 may also join to more than one shunt tube 12 . Entrance tubes 18 may have similar flow capacity to shunt tube 12 , or in an alternative embodiment, entrance tubes 18 may have a smaller flow capacity than shunt tube 12 . The flow capacities and angle of intersection of entrance tubes 18 with shunt tube 12 is chosen so as to prevent blockage from occurring within entrance tubes 18 or shunt tube 12 . That may be a concern, for example, should pumping be halted before a desired operation is completed. [0014] [0014]FIG. 1 shows centralizers 24 radially extending from base pipe 16 . Centralizers 24 are azimuthally spaced around the circumference of base pipe 16 and serve to keep base pipe 16 approximately centered in the wellbore. Shunt tubes 12 and entrance tubes 18 can be run between centralizers 24 and inside or outside a sand screen. (not shown). [0015] Because shunt tube 12 is an alternate pathway conduit, used to convey fluid past a blockage, it may be desirable to restrict fluid from entering entrance tubes 18 until shunt tube 12 is needed. That could be done by placing restriction members 26 such as valves or rupture discs across the openings of entrance tubes 18 . By using rupture discs, for example, flow into entrance tubes 18 , and therefore shunt tube 12 , would be prevented under normal operating pressures. However, if a blockage (bridging) occurred, pressure in the annular region could be increased until one or more discs burst, allowing fluid to pass. [0016] [0016]FIGS. 2 and 3 shows an alternative embodiment of the present invention. FIG. 2 shows a body 28 having channels 30 . Channels 30 can be milled or formed using other conventional methods. Channels 30 form pathways for fluid flow and essentially serve the functions of entrance tubes 18 . Channels 30 merge to direct their flow into one or more outlets 32 . There may be any number of channels 30 , the openings of which are azimuthally spaced. A cover 34 (FIG. 3) is mounted to body 28 to confine the fluid entering a particular channel 30 to travel through that channel 30 until it reaches an outlet 32 . Outlets 32 join to sand screen assemblies (not shown) using jumper tubes or other known connectors. [0017] In the embodiment shown in FIGS. 2 and 3, there are four channels 30 (though one channel 30 is obscured from view). Because there are two outlets in this instance, those four channels 30 are divided into pairs. The two channels 30 forming one particular pair merge to direct their fluid to one of the outlets 32 . The other pair similarly merges to direct its output to the other outlet 32 . Channels 30 can be merged by groups according to the number of outlets 32 available in any particular embodiment. Restriction members 26 can be placed in channels 30 to control access by the fluid until some operational condition is met. In the embodiment of FIGS. 2 and 3, base pipe 16 is preferably not slotted or perforated. [0018] In operation, a fluid such as a gravel slurry or fracturing fluid is pumped into an annular region between a production zone of the well and base pipe 16 . Often the fluid is initially pumped through a work string down to a crossover mechanism which diverts the flow into the annular region some distance below the well surface. In any case, when the fluid encounters entrance tubes 18 , it flows into entrance tubes 18 and travels through passageway 20 . Because entrance tubes 18 are azimuthally arranged, there is always at least one open fluid path through entrance tubes 18 into central passageway 14 of shunt tube 12 . That insures the fluid can pass into shunt tube 12 . [0019] The operation of the alternative embodiment is similar. The fluid is pumped into the annulus. When bridging occurs, the fluid backs up and the pressure increases. The fluid finds the openings of channels 30 and, in the absence of restrictor devices, flows into channels 30 and into shunt tubes 12 . In those embodiments employing restrictor members 26 , the fluid may be restricted from passing into the relevant passageway until the restriction member 26 therein is defeated. [0020] Although only a few example embodiments of the present invention are described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function.

The present invention provides for multiple pathways by which fluid can enter one or more alternate pathway conduits. Entrance tubes can be arranged such that their spacing prevents all of them from being simultaneously obstructed, covered, or otherwise blocked.

This application is a continuation of application Ser. No. 07/588,003, filed on Sep. 25, 1990, now abandoned. FIELD OF THE INVENTION This invention relates to an apparatus and method for forming an elastic corespun yarn and more particularly to an apparatus and method for forming an elastic corespun yarn wherein a nonelastic covering yarn is drawn into wrapping engagement with the elastic core yarn for forming an elastic corespun yarn. BACKGROUND OF THE INVENTION In many types of conventional wrapping apparatus for forming an elastic corespun yarn, and in some two-for-one twisting apparatus, a hollow rotating spindle carries a supply package of nylon or other nonelastic covering yarn. An elastic core yarn such as spandex is passed through the center of the hollow spindle. The nylon covering yarn is unwound from the rotating supply package and is wrapped around the elastic core yarn to form an elastic corespun yarn. The uninterrupted length of elastic corespun yarn formed by this apparatus is limited by the size of the covering yarn supply package which can be carried by the rotating spindle. Because the covering yarn is used at a much faster rate than the core yarn, the winding apparatus must frequently be stopped to replenish the covering yarn supply package. It has been proposed to provide a longer run of elastic corespun yarn by providing a wrapping apparatus where the covering yarn is drawn from a stationary yarn supply package into surrounding, ballooning relationship with a package of elastic core yarn carried by a fixed spindle. The elastic core yarn is metered from the package and the covering yarn is wound in wrapping engagement with the drawn core yarn. For example, in U.S. Pat. Nos. 2,737,773 and 4,309,867 to Clarkson and Ichikawa, respectively, the elastic core yarn is metered from a stationary supply package carried by a spindle. The elastic core yarn then is wrapped by the covering yarn. In U.S. Pat. No. 4,509,320 to Maeda, a core yarn package of elastic yarn is carried by a driven spindle while the drawn elastic core yarn is wrapped by the covering yarn. A tension device provides the proper amount of tension to the elastic core yarn during wrapping. The aforementioned apparatus provide for the production of larger units of corespun yarn with the attendant fewer winding stops necessary for replenishing a yarn supply package of the winding yarn. These apparatus, however, mandate operation at a decreased winding speed. Operation of the apparatus at higher spindle speeds increases the centrifugal force of the covering yarn causing the covering yarn to break. Operation of this type of apparatus at high spindle speeds is also limited because of the weight of the elastic core yarn unwinding mechanism. SUMMARY OF THE INVENTION It is therefore an object of this invention to provide an apparatus and method for forming an elastic corespun yarn and which overcomes the aforementioned deficiencies of the prior art. Another object of this invention is to provide an apparatus and method for forming an elastic corespun yarn wherein a nonelastic covering yarn is drawn from a supply package through the spindle and radially outwardly, upwardly and inwardly in a confined passage around and in spaced relation to a core yarn package supported by the spindle and then into wrapping engagement with the core yarn. These and other objects and advantages of the present invention are accomplished by an apparatus and method for forming an elastic corespun yarn which is characterized by having increased winding speed and the ability to produce a larger package of corespun yarn so that a covering yarn supply package of any desired size may be utilized to produce elastic corespun yarn of a length limited only by the length of the elastic core yarn which can be supplied by the core yarn package. The covering yarn is confined in its path of travel around the core yarn package thereby preventing breakage due to centrifugal force and air resistance even at very high spindle speeds. The apparatus includes a spindle holding frame having a spindle rotatably mounted thereon for rotation about a longitudinal axis. Drive means is operatively connected to the spindle for rotating the spindle about the axis. A core yarn package of relatively elastic yarn is carried by the spindle coaxially therewith. The core yarn package is held stationary relative to the spindle as the spindle rotates. A guide passageway is defined in the lower portion of the spindle along the longitudinal axis thereof for a predetermined distance upwardly from the lower end of the spindle and radially outwardly to the periphery of the spindle. Yarn confinement means in the form of a cylinder having eyelets positioned therein is mounted on the spindle for rotation therewith and defines a confined yarn guide passageway from the spindle guide passageway outwardly, upwardly and inwardly around and in spaced relation to a core yarn package supported on the core yarn support means for confining and guiding the covering yarn from the longitudinal axis of the spindle outwardly, upwardly and inwardly of the core yarn package. Means is provided for withdrawing an elastic core yarn from the core yarn package supported by the spindle and for feeding the elastic core yarn in a direction substantially along the spindle longitudinal axis thereof. Means is also included for withdrawing a nonelastic covering yarn from a supply package, through the spindle and yarn confinement means guide passageways, and into wrapping engagement with the elastic core yarn for forming an elastic corespun yarn. BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages will appear as the description proceeds when taken in connection with the accompanying drawings in which: FIG. 1 is a fragmentary elevational view of the apparatus for forming a corespun yarn in accordance with the present invention; FIG. 2 is an enlarged fragmentary sectional view of the spindle in accordance with the present invention; FIG. 3 is an enlarged partial sectional view of the dotted line area marked 3 in FIG. 2 and showing in detail the formed corespun yarn; and FIG. 4 is an enlarged vertical sectional view of the tension control device shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, FIG. 1 illustrates the apparatus of the present invention for forming an elastic corespun yarn, broadly indicated at C, wherein the apparatus is characterized by having an increased winding speed and the ability to produce a larger package of corespun yarn C. As shown in greater detail in FIG. 2, the apparatus includes a spindle assembly, broadly indicated at 15, which includes a spindle holding frame 16 with respective upper and lower cantilevered arms 17, 18. It is to be understood that a plurality of these spindle assemblies 15 are provided in side-by-side relationship in two full rows along the outside of an elastic yarn spindle wrapping machine. A spindle, broadly indicated at 20, is rotatively mounted in the cantilevered arms 17, 18 by means of respective upper and lower bearing assemblies 21, 22 so that the spindle defines a longitudinal axis extending through both of the arms. Additional bearing assemblies 23, 24 rotatably support the lower portion of the spindle 20. The spindle 20 includes a lower spindle portion 30 mounted for rotation in the three sets of bearings 22, 23 and 24. The lower spindle portion 30 is hollow and includes a lower guide passageway 31 defining an axial passageway extending in the lower portion of the spindle, and an exit orifice or passageway 32 exiting radially from the spindle 20. An upper hollow spindle portion 35 is mounted for rotation in the upper cantilevered arm 17 by the upper bearing assembly 21 therein. The upper spindle portion 35 includes an upper guide passageway 40 extending coaxially through the top portion and exiting coaxially therefrom. As illustrated in FIG. 2, the medial portion of the spindle 20 includes respective top and bottom conical caps 41, 42 and a cylinder 45 is secured to the caps 41, 42 and coaxially therebetween so that as the spindle 20 rotates, the cylinder 45 rotates therewith. The cylinder 45 is positioned so that the radially extending exit orifice 32 is positioned within the confines of the cylinder 45. A first eyelet 46 is fixed inside the cylinder 45 where the lower cap 41 and cylinder 45 connect. A second eyelet 47 is fixed above the first eyelet 46. Both eyelets 46, 47 and the cylinder 45 define a confined yarn guide passageway from the spindle guide passageway 31 and orifice 32 outwardly, upwardly and inwardly in the cylinder 45. Additionally, a tube (not shown) can extend between the exit orifice 32 and the first eyelet 46, between the eyelets 46, 47 and between eyelet 47 and the upper guide passageway 40 to facilitate threading by vacuum drawing instead of by conventional mechanical threading apparatus. Preferably, the cylinder 45 is made from a strong, lightweight material, such as titanium or a composite, lightweight material such as carbon fiber. Drive means, in the form of an endless drive belt 50, is operatively connected to the spindle 20 for rotating the spindle 20 about the longitudinal axis. The belt 50 engages a cylindrical drive hub 51 positioned on the lower spindle portion 30. As the belt 50 moves at a high speed, it engages the lower spindle portion 30 to rotate the spindle at a very high RPM--as much as 50,000 to 60,000 RPM. A yarn package support carrier 60 is positioned on the upper part of the lower spindle portion 30 and extends above the radially extending exit orifice 32. The support carrier 60 is inside the confines of the cylinder 45 for supporting, in substantial axial alignment with the spindle 20, a core yarn package 61 of relatively elastic yarn 63, preferably spandex. The yarn package support carrier 60 is provided with spaced upper and lower bearings 62 which receive and support the core yarn package 61 so that the elastic core yarn 63 may be withdrawn therefrom. The yarn package support carrier 60 includes a permanent magnet 65 positioned therewithin. A cantilevered support arm 66 is provided adjacent the outer perimeter of the cylinder 45 and has a free end partially surrounding the cylinder 45. A magnet 70 (FIG. 2), which can be a permanent magnet or an electromagnet, is fixed in the arm 66 and adjacent the perimeter of the cylinder 45. The magnet 70 provides an attracting magnetic force for attracting the permanent magnet 65 positioned on the yarn package support carrier 60 and for holding the yarn package support carrier 60 stationary relative to the spindle 20 as the spindle 20 rotates. When the core yarn package 61 is positioned on the yarn package support carrier 60, in the manner illustrated, a yarn tension applicator or control device, broadly indicated at 80, is positioned on the upper end of the spool of the core yarn package 61 to provide the required amount of tension to the core yarn 63 as it is drawn off the yarn package 61. Various types of conventional tension control, such as the illustrated disc type, can be used. As illustrated in greater detail in FIG. 4, the illustrated tension control device 80 includes a support bracket 81 fixed at its lower end on the upper portion of a thrust bearing 83 and positioned at the lower portion of the housing. The thrust bearing is dimensioned for receipt onto the spool 61a of the yarn package 61. The thrust bearing 83 allows the yarn tension control device 80 to rotate as needed during the wrapping operation of the covering yarn 12 onto the core yarn 63. The yarn tension control device 80 includes upper and lower grommets 86, 87 for allowing the core yarn 63 to pass therethrough with minimal friction. Positioned in the housing are a pair of discs 90, 91 engaging each other and supported by a threaded shaft 92 extending through the bracket 81. A yarn passageway 93 extends between the discs 90, 91 and the shaft 92 for allowing the core yarn 63 to pass therebetween. A spring 95 is positioned between one of the discs and a wing nut 96, and pressure may be increased or decreased against the other disc by turning the wing nut 96 positioned on the threaded shaft 92. Pressure is increased by turning the wing nut 96 inward to increase spring pressure against the discs, thus resulting in increased tension on the core yarn drawn therebetween. When the wing nut 96 is turned outward, spring pressure is decreased resulting in a decreased tension on the core yarn. If a magnetic tensioner is used, tension automatically can be adjusted. With the illustrated embodiment, an opening (not shown) can be provided in the cylinder wall for allowing an operator to manually adjust tension. A lower set of rolls 98 are positioned beneath the spindle 20 for aiding in guiding a covering yarn 63 upwardly through the lower guide passageway 31. An upper set of rolls 99 working with a take-up roll 100 draw the formed corespun yarn C. METHOD OF OPERATION Initially, a covering yarn is threaded through the lower set of rolls 98 into the lower guide passageway 31, outward into the cylinder 45 and through the eyelets 46, 47. When a tube is used as described above, vacuum may be used for threading the yarn. Otherwise, a mechanical threading apparatus is used. The covering yarn 12 is drawn in wrapping engagement with the core yarn 63 and the resulting corespun yarn C is drawn upward through the upper guide passageway 40 to the upper set of draft rolls 99 where it is wound on the core of a take-up roll 100. The spindle 20 is rotated at a high RPM ranging from 50,000 to 60,000 RPM. The upper set of rolls 99 pull the formed corespun yarn C upwardly while pulling the core yarn 63 and the covering yarn 12 from their respective yarn packages 61, 11. As the spindle 20 rotates, the covering yarn 12 is centrifugally forced against the inside wall of the cylinder. During high speed spindle operation, the cylinder 45 and eyelets 46, 47 guide the covering yarn 12 to a restricted diameter for preventing breakage of the covering yarn. The covering yarn rotates with the cylinder and is forced into wrapping engagement with the core yarn to form the resulting corespun yarn (FIG. 3). Additionally, the magnet 70 is energized for preventing rotation of the yarn package support carrier 60 having the core yarn package supported thereon. The invention offers several benefits over other prior art apparatus. Because the covering yarn package is not carried by the spindle, longer runs of the apparatus can be accomplished without changing the yarn packages. Additionally, the cylinder in which the covering yarn is confined during its centrifugal, advance upward prevents breakage of the covering yarn during high speed spindle operation. In the drawing and specification there has been set forth the best mode presently contemplated for the practice of the present invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

A spindle is mounted to a frame for rotation about the spindle axis. A core yarn package of elastic core yarn is held stationary on the spindle. Elastic core yarn is withdrawn from the core yarn package in a direction substantially along the spindle longitudinal axis. A nonelastic covering yarn is drawn from a supply package, through the spindle and along a confined yarn guide passageway from the spindle guide passageway outwardly, upwardly and inwardly around and in spaced relation to the core yarn package for confining and guiding the covering yarn, and then into wrapping engagement with the withdrawn core yarn to form a corespun yarn.

BACKGROUND OF THE INVENTION This invention relates to overload protectors and more particularly to an overload protector which protects a tool activated by a programmable robot to prevent the tool from being overloaded or being forced into an abnormal position. In Canadian patent no. 2,004,661 issued to Kaz M. Szmyr, one of the applicants herein, an overload protector is described in which the tool to be protected is attached to a flange which is located within the cavity of a housing. Fluid under pressure is contained within the cavity and the pressure of that fluid forces the flange into a wall of the cavity. There is an opening in that wall and when the flange is forced against the wall it seals the opening shut. Movement of the tool caused by overloading or abnormal forces applied to it results in movement of the flange away from the wall. Such movement allows fluid within the cavity to escape through the opening and the pressure within the cavity drops. A pressure switch detects the drop in pressure and signals the robot to stop. Should the tool be subject to torsion, the flange rotates relative to the wall of the housing. Ball bearings are provided in the inside wall of the flange and in the wall of the cavity that faces it. As the flange rotates, the ball bearings force the flange to move away from the hole and fluid within the cavity escapes. The location of the ball bearings on the flange governs the amount of torsional force required to cause them to force the flange away from the cavity wall. The further those ball bearings are from the centre of the flange the more torsional force must be applied to the flange before the ball bearings force the flange away from the wall. It has been found that cones can be substituted for ball bearings with improved results. The cones may be in the form of conical detents which are formed in the cavity wall and which are received in conical recesses at the periphery of the flange. Greater axial, angular and torsional movement or compliance can be achieved by this means than by ball bearings. The reason is that ball bearings will tend to roll out of their recesses should such movement be more than very limited and once out cannot be reset into their recesses without dismantling the protector. Conical detents and recesses, on the other hand, permit significantly more of such movement. Moreover should the detents separate from the recesses, the protector need not be taken apart to reset the detents into the recesses. Conical detents and recesses have another advantage. Should unlimited rotational movement or torsional compliance be required, the detents can be shortened so that they will ride completely out of their recesses should a tool be subjected to a high speed collision. In such event the protector will have more time to signal the robot to stop and, after it has stopped, the detents can be easily reset into the recesses manually by an operator. Should the intensity of the collision be insufficient to cause the detents to ride out the recesses but sufficient to cause them to ride up in the recesses, a spring within the protector will reset the detents automatically into the proper position after the robot has stopped the tool and no manual resetting is necessary. It has also been found that the sensitivity of the overload protector to axial forces applied to the tool can be enhanced by attaching to the flange an assembly which is slidable to a limited extent relative to the flange. The assembly is designed to allow fluid within the cavity to escape even though the axial force which overloads the tool is insufficient to overcome the pressure of the fluid on the flange. According to one embodiment of the improvement, the flange has a circular peripheral wall having a plurality of semi-conical recesses formed therein. The cavity has semi-conical detents formed in its wall. The recesses and detents are arranged such that the detents are accommodated within the recesses when the flange assembly is in a sealing relationship with the wall of the cavity. Alternatively the cavity may have recesses in its wall and those recesses are received in detents in the periphery of the flange. According to another embodiment of the improvement, a hub assembly is attached to the flange and is designed to slide a limited distance relative to the flange. The tool is operatively connected to the assembly such that when the tool is overloaded in such a way that it causes the assembly to advance toward the flange, fluid leaks from the cavity with resulting drop in the pressure of the fluid within the cavity. DESCRIPTION OF THE DRAWINGS The invention is described in detail with reference to the accompanying drawings in which: FIG. 1 is a perspective view of the overload protector shown in conjunction with a robot and a tool; FIG. 2 is an exploded perspective view of the components of the overload protector; FIG. 3 is a section of the overload protector; FIGS. 4, 5, and 6 are sections of the overload protector when the tool (not illustrated) to which the protector is attached is subject to abnormal forces. In FIG. 4, the tool is subject to torsion or compression; in FIG. 5 the tool is subject to compression and in FIG. 6 the force is offset from the centre line of the tool. Like reference characters refer to like parts throughout the description of the drawings. DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIG. 1, the overload protector of the invention is indicated generally by the numeral 10 and is shown connected at one side to a working tool 12 and at the other side to the free end of the arm, generally 14, of a robot. The robot arm is mounted upon a base 16. In FIGS. 2 and 3 the tool is mounted to a so-called "rocker assembly" made up of a hub assembly including a hub 20, a hub cap 22, a flange assembly including a main ring 24 and a locating ring 30. The hub has a flange 20a to which the tool is bolted and a hollow cylindrical wall 20b. The inner surface of the hub is threaded and those threads mate with threads 22a formed on the outer wall of the hub cap 22. The cylindrical wall of the hub is received within a cylindrical wall formed in the main ring 24. Longitudinally extending grooves 20d are formed in the cylindrical wall of the hub and at 24a in the bore of the main ring. These grooves are arranged in pairs so that when one groove in the hub faces one groove in the main ring, each remaining groove in the hub faces a groove in the main ring. A dowel 25 is accommodated in every second pair of facing grooves while the remaining pairs of grooves which face each other are empty. Those dowels prevent the hub from rotating relative to the main ring. With reference to FIG. 3, the main ring 24 has a lower wall, the inner portion of which rests on the hub cap 22 at 26 and the outer portion of which defines the upper wall of a cavity, generally 28. The upper wall of the main ring is separated from the flange of hub 20 by a gap 27 and the inside wall of the main ring abuts the cylindrical wall of the hub and is slidable relative thereto. The terms "lower" and "upper" in the description of the components of the overload protector are intended to facilitate an understanding of the drawings. The terms are not intended to suggest that the orientation of the overload protector must be as shown in the drawings. In fact, the protector may be oriented in any way; it may for example be on its side, upside down or as illustrated in the drawings. A locating ring 30 is attached by means of bolts 32 to the flange of the main ring. The locating ring together with the flange of the main ring to which it is bolted together make up a so-called "flange assembly". The locating ring has a number of semi-conical recesses 36 spaced along its periphery. The rocker assembly is mounted within a housing which includes an upper ring 40, a central body 42 and a lower plate 44. These components are interconnected by means of bolts 48b. The lower wall of cavity 28 is defined by the lower plate 44. The plate is connected either directly or indirectly to the free end of the arm 14 of the robot. As illustrated in FIGS. 2 and 3, the side wall of the cavity is defined by a circular interior wall 42a of the central body 42. That body has a lower cylindrical wall 42e and an upper flange 42c. Above the central body is the upper ring 40. A port 43 is formed in wall 42e so that air or other fluid may be introduced under pressure into cavity 28. The central body 42 has a number of semi-conical recesses 50 formed in its interior wall 42d and each of those recesses is adjacent to or faces one of the recesses 36 formed in locating ring 30. Thus each pair of openings 36, 50 defines a complete conical recess. An insert 52 is received in each recess 50 and is held stationary therein by means of upper ring 40. When the tool is not overloaded the inserts 52 have conical outer walls and, being stationary, act as detents which, when the inserts are in the recesses formed in the locating ring, prevent the central body 42 from rotating relative to the locating ring. However, as explained below, when the tool is overloaded the rocker assembly will ride up and the detents in the main ring will exit from the recesses 50 in the locating ring. Preferably the inserts 52, central body 42 and locating ring 30 are formed of hardened steel to ensure that the sudden violent forces to which these components may be subject when a tool is overloaded do not cause excessive wear. An annular shield 56 formed of flexible material such as rubber is received in a central circular depression 40a formed in upper ring 40. The shield is sandwiched between the upper ring and a retaining ring 58 and the two rings are inter-connected by means of screws 60. The shield 56 prevents dirt, water and other foreign material from entering cavity 28 and interfering with the operation of the flange. A number of O-rings serve to seal the cavity when the overload protector is not overloaded or is not forced into an abnormal position. Ring 62 acts as a seal between lower plate 44 and central body 42. That ring is received in an annular groove 64 formed in the wall of the lower ring in contact with the central body. A second O-ring 66 is received in an annular groove 68 formed in main ring 24 and that ring contacts the lower surface of the flange of central body 42. A third O-ring 70 is received in an annular recess 72a formed in hub cap 20 and that ring contacts main ring 24. The two plates 74, 78 serve to reduce the wear on the spring. Resilient means in the form of a coil spring 72 rests on a lower retaining plate 74 having a hemispherical central portion 76 which is received in the central opening of the spring to prevent the spring from moving laterally. The retaining plate is attached to mounting plate 46. The upper portion of the spring is restrained from lateral movement by means of an upper retaining plate 78 which is attached to hub 20. The rocker assembly of the overload protector is attached to the tool while the arm of the robot is attached to the housing. The upward pressure of the coil spring as well as the pressure of fluid within cavity 28 will urge the rocker assembly upwardly in the housing so that locating ring 30 contacts the lower surface of upper ring 40. Inserts 52 serve to locate the rocker assembly in the housing so that the O-rings are effective to seal the cavity. Fluid under pressure in the cavity acts on the underside of the rocker assembly and is the principal means for holding the assembly in a sealing relationship within the housing. Should the tool be overloaded or forced into an abnormal position the rocker assembly will move relative to the housing. Such movement may be in various directions. 1. Torsion With reference to FIG. 4, should the force acting on the tool cause it to rotate, the rocker assembly will likewise rotate in the housing. Locating ring 30 will accordingly rotate relative to the central body 42. As the ring rotates, the detents will bear against the walls of the recesses in the locating ring and will force the ring downward. Such movement will break the seal between the main ring and the central body 42 and fluid within the cavity will escape to the atmosphere. The drop in pressure in the cavity will be detected by a pneumatic control device which sends a signal to the computer. That device controls the robot and causes it to cease operating. There is a description of the means by which a pressure switch operates to send the signal to the computer in the aforementioned Canadian patent no. 2,004,661 and that description is incorporated into this application. 2. Compression (i) Slight Compression: With reference to FIG. 5 should the tool contact a foreign object which causes the tool to move slightly downward in the direction of arrow 82, hub 20 and hub cap 22 will move downward but the main ring 24 will not. That is because the pressure of the fluid within the cavity acts on its lower surface of the main ring and holds it up. As the hub and hub cap move downward, the sealing effect of O-ring 70 will be broken and a gap opens at 83 between the hub cap and the main ring. Fluid in the cavity escapes through whichever pairs of grooves 20d, 24a in the hub and the main ring, respectively, that do not contain a dowel. The main ring will remain stationary only momentarily until the pressure of fluid in the cavity has diminished to the point where the downward force acting on the tool exceeds the upward force acting on the flange by fluid in the cavity and by spring 72. (ii) Greater Compression: With reference to FIG. 4, greater movement of the tool in the direction of arrow 84 will cause the gap 26 to close and the flange of the hub cap will force the main ring downward. When the lower wall of hub cap 22 strikes plate 44 such movement will cease. As the flange moves downward, a gap will open between main ring 24 and central body 42. Fluid within the cavity will escape through that gap and through the space between the flexible shield 56 and flange 20a. The drop in pressure in the cavity will be detected by a pneumatic control device as described above. 3. Force Offset from the Centre Line of the Tool With reference to FIG. 6, a force is directed laterally against the tool thereby causing the rocker assembly to teeter or rock in the direction of arrow 90. As it does so, fluid escapes between locating ring 30 and central body 42 on the left side of the overload protector. On the right side, the outer edge of the main ring 24 rides up against the central body and the sealing effect of O-ring 66 is lost. It should be noted that because of the close fit of the hub and hub cap in the main ring 24, no movement of these components relative to each other will occur when an offset force is applied to the tool. It will be understood of course that modifications can be made in the preferred embodiments illustrated and described herein without departing from the scope and purview of the invention as defined in the appended claims.

An overload protector is provided which is secured to a robot arm and a tool to protect the tool form being overloaded or forced into an abnormal position. A rocker assembly is located within the cavity in the protector and the cavity is pressurized in order to force a wall of the rocker assembly into a sealing relationship with a wall of the cavity. The rocker assembly has a peripheral wall in which a number of semi-conical detents are formed in the wall of the cavity. The detents are accommodated in the recesses when the rocker assembly is in a sealing relationship with the cavity wall. When the tool is overloaded or forced into an abnormal position the rocker assembly rocks in the cavity with resulting leakage of fluid from the cavity and a drop of pressure. A pressure switch detects that drop and signals the robot to stop.

CROSS-REFERENCE TO RELATED APPLICATION This is a divisional of Application Ser. No. 888,996 filed July 31, 1986 and now U.S. Pat. No. 4,783,524 issued Nov. 8, 1988, which was a continuation-in-part of application Ser. No. 777,117 filed Sept. 17, 1985, now abandoned. BACKGROUND OF THE INVENTION Insulin-like growth factors (IGF's) have been identified in various animal species as peptides that are biologically active in growth, e.g. via proliferation of cells. They are believed to mediate effects of somatotropins and possibly other hormones. The designation "insulin-like growth factor" was chosen to express the insulin-like structures and effects of these peptides. IGF's have nearly 50% homology with insulin. In three dimensional structure they resemble proinsulin, i.e., they are single-chain peptides cross-linked by three disulfide bridges and containing an A-chain portion (A domain), a B-chain amino-terminal portion (B domain) and an A-B connecting chain (C domain). A carboxy-terminal extension (D domain) not found in proinsulin is also present in at least some IGF's. Several classes of IGF's have been identified in animals. Normally these include IGF-I, IGF-II and others. Circulating levels of these peptides appear to be under the control of somatotropin to some extent, with IGF-I controlled to a greater extent than IGF-II. In various cell culture systems, IGF's have shown mitogenic effects measured, e.g., by increased tritiated thymidine incorporation. It has been demonstrated that in some animals, at least two sets of IGF receptors exist, one preferentially binding IGF-I and the second IGF-II, suggesting separate functions for IGF-1 and IGF-II. However, the biological functions of IGF-II appear to vary among mammalian species. For example, while rat IGF-II levels have been found 20-100 fold higher in fetal than maternal circulation, human serum IGF-II in the fetus is normally lower than in adults. Because of its potential bioactivity and utility for enhancing desirable cell growth in animals, the amino acid sequence of bovine IGF-II ("bIGF-II") has long been sought together with a more detailed understanding of its growth-promoting and other activities, its active fragments, etc. Heretofore, neither that sequence nor the DNA sequence of the bIGF-II gene has been reported. Studies with rat and human genomic libraries suggest that IGF-II genes contain at least four exons. The large size and complexity of the genes for human and rat IGF-II have made their isolation and identification so difficult that the DNA sequences of those genes have not yet been fully determined. For purposes of making and studying bIGF-II, however, there has been a need to isolate and determine the complete DNA sequence of the bIGF-II gene. Accordingly, it is an object of this invention to provide highly purified and/or synthetic peptides having one or more of the biological activities of bIGF-II and, more generally, such peptides consisting essentially of amino acids providing such activity, or peptides which can be readily converted to those having such activity. It is another object of this invention to provide methods using such peptides to promote desirable growth or functionality of cells in animals including, e.g., muscle and/or mammary epithelial cells. Another object of this invention is to provide DNA useful in making such peptides. Another object of this invention is to provide processes utilizing such DNA in the production of such peptides. Other objects will be apparent from the detailed description herein and the appended claims. SUMMARY OF THE INVENTION This invention is based largely on the herein-reported original discoveries of the amino acid sequences of bIGF-II and various precursors thereof, and the nucleotide sequences of DNA coding for bIGF-II and such precursors, all as shown hereinbelow. In one embodiment, the invention provides certain novel peptides consisting essentially of the following sequence of amino acids (reading from the amino end to the carboxy end of said sequence) which correspond to the heretofore-undetermined amino acid sequence of bIGF-II: ______________________________________Ala--Tyr--Arg--Pro--Ser--Glu--Thr--Leu--Cys--Gly--Gly--Glu--Leu--Val--Asp--Thr--Leu--Gln--Phe--Val--Cys--Gly--Asp--Arg--Gly--Phe--Tyr--Phe--Ser--Arg--Pro--Ser--Ser--Arg--Ile--Asn--Arg--Arg--Ser--Arg--Gly--Ile--Val--Glu--Glu--Cys--Cys--Phe--Arg--Ser--Cys--Asp--Leu--Ala--Leu--Leu--Glu--Thr--Tyr--Cys--Ala--Thr--Pro--Ala--Lys--Ser--Glu.______________________________________ In other embodiments, the invention provides various methods for promoting growth and/or other desirable functions of cells in animals by administering peptides of this invention to animals in amounts sufficient to cause such effects. For example, animal muscle mass can be increased by suitably administering to the animal an amount of such peptide(s) effective to cause proliferation of satellite muscle cells in that animal. In another illustration, such peptide(s) can be suitably administered to female mammals in amounts effective to cause proliferation and/or galactopoietic stimulation of their mammary epithelial cells such that subsequent lactation is enhanced. In other embodiments, the invention provides certain novel nucleotide sequences (DNA) coding for such peptides. Typically, this DNA contains essentially the following sequence of nucleotides (or their functional equivalents for peptide expression): ##STR1## In other embodiments, the invention provides processes for producing such peptides by effecting expression of such DNA, recovering and then optionally further purifying the resulting peptides, e.g. to an essentially pure form. DETAILED DESCRIPTION OF THE INVENTION As used herein, the symbols representing amino acids (e.g. Ala for alanine) and nucleotides (C, A, G or T) are those conventionally employed. See Lehninger (1976). The Peptides As used herein, the term "synthetic peptide" means a peptide produced by a technique (e.g. chemical synthesis or recombinant DNA expression) other than its natural production in a living animal. Accordingly, the "synthetic" peptides of this invention are to be distinguished from peptides produced in living animals via expression of DNA occurring naturally in those animals. As produced, such "synthetic" peptides are normally free from peptides of bovine (and usually other animal) origin. In other embodiments, however, peptides of this invention can be prepared by isolation from peptide mixtures produced in living animals, e.g. as in Example 1. Using any mode of preparation in which a peptide of this invention is isolated from other peptide(s) of bovine or other animal origin, the isolation is typically carried out to provide a peptide of this invention essentially free from such other peptide(s), i.e., mixed with little enough of such other peptide(s) that the latter do not interfere substantially with the desired bioactivity of the peptide of this invention. As used herein, references to peptides "consisting essentially" of the sequence of bIGF-II (alone or extended at either or both of its amino and carboxy termini) should be understood as referring to peptides comprising the recited sequence or only as much of that sequence as is needed to provide one or more of the biological activities of bIGF-II in substantial measure (typically at least about 0.1%, preferably at least about 1% and even more desirably at least about 10% of that activity of pure intact bIGF-II). Those biological activities of bIGF-II include, but are not limited to, insulin-like activity and the ability (alone or with other biologically active substances) to stimulate animal cell proliferation or lactation by already-formed mammary epithelial cells. Amino acids that are essentially superfluous with respect to such activity can be omitted, resulting in peptides of fewer amino acids than are contained in the recited peptide itself. Also embraced by such references are peptides which have such activity despite the presence therein of one or more amino acids substituted for any of those in the amino acid sequences (shown herein) of bIGF-II or its naturally-occurring precursors. For example, peptides in which a methionine is substituted for the amino-terminal alanine in the bIGF-II sequence shown above is expected to have bIGF-II-like activity and to be readily producible via recombinant DNA (rDNA) in bacteria or other microorganisms that do not remove such an N-terminal methionine residue. Also embraced by such references are various larger peptides containing the recited sequence (or such a deletion and/or substitution variant thereof) together with one or more additional amino acids directly attached to its amino and/or carboxy terminus, as well as such peptides otherwise modified at their termini or elsewhere, e.g. by glycosylation, phosphorylation, amidation or the like, to the extent such peptides can be used (with or without further processing) to provide a biological activity of bIGF-II in substantial measure. In one approach employed in identifying the bIGF-II amino acid sequence disclosed herein, bIGF-II was isolated and purified from bovine serum. Although the liver is the major source of IGF production in most animals, and IGF's have been detected in many body tissues such as muscle, cartilage, brain and cerebral spinal fluid, serum is the preferred source of IGF's generally, and IGF-II specifically. Methods for separation and isolation of IGF's have been described in the art, e.g. by Svoboda et al., Van Wyk et al., Liberti, Bala et al. and Zumstein et al. The active bIGF-II isolated and purified from bovine serum in accordance with the present invention was found to be a single peptide having a molecular weight of about 7400 daltons and the sequence of 67 amino acids shown above. A preliminary screen for biological activity associated with the purified bIGF-II and quantitation thereof was performed by a rat placenta radioreceptor assay described in Daughaday et al. The present discovery of the complete amino acid sequence of bIGF-II is significant as it provides a basis for production of peptides having bIGF-II activity. Such production can be carried out by any available process. For example, small (e.g. research) quantities can be produced using conventional peptide synthesizing equipment. On a larger scale, such production can be carried out by chemical synthesis or, usually more satisfactorily, in microbial hosts or cell cultures utilizing rDNA coding for peptides of this invention. Using such DNA in conjunction with techniques of genetic engineering, there can be manufactured much larger quantities of such peptides than could ever be practically recovered from bovine serum or tissues. As described more fully below, the amino acid sequence of bIGF-II has now been confirmed by isolating and characterizing bIGF-II gene fragments from bovine kidney genomic DNA. Even before such gene characterization, however, synthetic peptides of this invention simulating bIGF-II structurally could be produced following the herein-reported discovery of the bIGF-II amino acid sequence, e.g. by known techniques using rDNA made to code for that amino acid sequence. Thus, when such peptides are to be produced using rDNA in microbial hosts such as bacteria or yeast, a DNA sequence coding for that amino acid sequence and optionally composed of bIGF-II codons preferred by the selected host (see U.S. Pat. No. 4,356,270 issued Oct. 26, 1982 to K. Itakura) can be designed and produced synthetically. Production of peptides of this invention by rDNA and/or chemical synthesis may result in minor alterations in amino acid composition. For example, production in bacteria may result in addition of a methionine at the amino (N-) terminus, chemical synthesis may result in variations of the carboxy (C--) terminus such that any of the radicals --COOR:, --CR 1 O, --CONHNR , --CONR 1 R 2 or --CH 2 OR (R 1 and R 2 being independently lower alkyl or hydrogen) may be found. These peptides are among those of the present invention insofar as their bIGF-II-like biological activity is not diminished to an intolerable degree. In some instances, peptides of this invention will be isolated or prepared in a denatured, biologically inactive condition. In its normal, biologically-active (undenatured) state, bIGF-II is cross-linked by three disulfide bridges. By analogy to human IGF-II and IGF-1, these bridges are believed to exist between amino acid (cysteine) positions 9 and 47, 21 and 60, and 46 and 51 (see Yamashiro et al.), but the scope of this invention is not to be limited thereto. Peptides of this invention that lack such desired bridging can be activated by peptide naturation techniques well known in the art, usually by subjecting the peptide to conditions (pH, temperature, oxidizing environment, etc.) under which it assumes its biologically active, three-dimensional configuration and forms the disulfide bonds (bridges) similar to those in biologically active bIGF-II. The particular technique employed is not critical for purposes of this invention so long as biological activity is conferred to the extent desired. The amino acid sequence differences between human, rat and bovine IGF-II's occur mainly in the regions generally characterized as their C domains. bIGF-II analyzed for purposes of the present invention was consistently found to have an N-terminal alanine as shown in TABLE II. This was consistent with the N-terminal alanine reported for human and rat bIGF-II's by Humbel but at variance with the N-terminal tyrosine (des Ala) reported for human IGF-II in Rinderknecht et al. and rat IGF-II in Marquardt et al. Such bIGF-II's having an N-terminal tyrosine may exist as a result of allelic and/or processing variations not detectable from the bovine serum used herein, or as a consequence of unintended deletion of the N-terminal alanine during purification. In any event, such N-tyrosine variants are to be considered equivalents of the peptides of this invention to the extent they have bIGF-11 biological activity. With the herein-reported amino acid sequence and biological activities of bIGF-II, it is now possible to identify allelic forms of bIGF-II and/or make bIGF-II variants having biological activities equal or superior to those of bIGF-II. Hence it is anticipated that the isolation of allelic forms of bIGF-II and production of such variants having amino acid deletion(s), substitution(s) and/or addition(s) with respect to bIGF-11 will provide various useful embodiments of the peptides disclosed herein. Identifying such alternative peptides is within the ability of those skilled in the art. From DNA sequencing described below, and by analogy to human IGF-II ("hIGF-II"), it is believed that bIGF-II is first synthesized intracellularly as a precursor peptide having a signal (leader) sequence of at least 24 amino acids immediately preceding the N-terminus of the mature bIGF-II and that, on secretion of the precursor peptide from bIGF-II-producing cells, that signal sequence is cleaved. The peptides of this invention containing such a signal sequence (or any desired portion thereof) can be produced by expression of such DNA (first deleting the codon(s) for any amino acid(s) not wanted in that sequence) and are useful for production of peptides of this invention corresponding in amino acid sequence to mature bIGF-II, e.g. via chemical, microbial or enzymatic removal of that signal sequence. From other novel DNA sequences disclosed herein, it is believed that there is a bIGF-II precursor peptide having a carboxy-terminus extension containing about 89 amino acids. The novel sequence of the first 68 amino acids of that extension (beginning at the carboxy terminus of bIGF-11) is disclosed herein. By analogy to proinsulin, it is believed that peptides of this invention containing such a carboxy extension provide the biological activity of bIGF-II in substantial measure and accordingly, these extended peptides are within the scope of the present invention. Uses of the Peptides As described more fully below, the isolation and characterization of bIGF-II in accordance with the present invention has provided an opportunity to more clearly identify and define aspects of the bioactivity of bIGF-II. For example, it has been found that bIGF-II is active in the rat L6 myoblast cell proliferation assay and is able to stimulate proliferation of bovine mammary epithelial cells and lactation by such mammary cells in vitro. Accordingly, it is considered that the peptides of this invention have activity for in vivo proliferation of various bovine cells, e.g. mammary epithelial and satellite muscle cells, and for in vivo stimulation of already-formed mammary epithelial cells to increase their rate of milk production. It is further considered that peptides of the present invention are effective for similarly increasing the muscle content and/or lean-to-fat ratio in animal species other than cattle (e.g. sheep, goats, swine, chickens, turkeys, ducks and other fowl) and for increasing lactation in mammals other than cattle (e.g. sheep, goats and swine) when sufficient homology exists between bIGF-II and the IGF-II's of such animal species. In adult animals, the myofiber (e.g. muscle cell) number is fixed so that increased muscling results only from muscle cell hypertrophy and proliferation of satellite muscle cells. Myofibers are formed in utero by the fusion of replicated embryonic muscle cells. Replicating muscle cells which persist in the adult are called satellite muscle cells. Satellite muscle cells may be stimulated to replicate and thereafter fuse with existing myofibers to yield increased myofiber nuclei. This increase in myofiber nuclei is expected to manifest itself as increased muscle content (mass). The L6 myoblast proliferation assay provides a reliable in vitro indicator of IGF activity and is used as a model for factors affecting embryonic myoblasts and adult satellite cells. Factors active in this system behave similarly in primary cultures of bovine myoblasts. See Gospodarowicz et al. The enhancement of rat L6 myoblast proliferation in vitro by a peptide of this invention indicates its activity in causing increased myoblast proliferation and, therefore, an increase in ultimate myofiber number in utero. In addition, similar enhancement of rat L6 myoblast proliferation indicates that peptides of this invention can be used to enhance adult muscle hypertrophy, e.g. via stimulation of satellite muscle cell proliferation. In lactating animals, the amount of mammary epithelial tissue is a limiting factor in milk production, as these are the cells which produce and secrete milk. Employing in vitro systems, it has been demonstrated that epithelial cells obtained from mammary glands of animals can be stimulated by bIGF-II to proliferate to produce increased quantities of milk constituents. It has further been demonstrated that mammary epithelial cells stimulated to proliferate in one such in vitro cell system can be reimplanted in cleared mammary fat pads (see Yang and Nandi) where they can be stimulated to proliferate and/or produce milk. These discoveries indicate that peptides of this invention are biologically active in vivo for increasing bovine lactation, e.g. by any suitable administration to pregnant cows or heifers. One such technique is described in copending U.S. Pat. application Ser. No. 837,477 filed Mar. 7, 1986, the disclosure of which is incorporated herein by reference. Thus, the peptides of this invention are useful for administration to animals, especially (but not only) nonhuman animals, for increasing milk production and/or the lean-to-fat ratio or muscle content in animals. For purposes of such uses, one or more peptides of this invention (or non-toxic salts thereof) can be combined with a non-toxic, physiologically acceptable carrier (liquid or solid) to form a composition which can be administered to animals by any suitable technique, e.g. intravenously, subcutaneously, intramuscularly, intranasally, or orally in a form that protects the peptide from degradation in the digestive tract. Such compositions can be administered to the animal by injection, infusion or implantation, preferably in a medium (e.g. dispersion in oil or a polymer) which facilitates delivery of the peptide to target cells of the animal at a desired rate. The proportions of carrier and biologically active peptide in such compositions can be any that facilitate the desired effects in animals. Preferred proportions can be readily determined by those skilled in the art. The required dosage will vary with the particular result sought and duration of desired treatment. The amount or dosage most effective for achieving a desired result (e.g. increased milk production) can be determined by routine experimentation. The preferred dosage may depend on such variables as the size, general health and nutritional status of the specific animal. Bioactive peptides of this invention can be used in an essentially pure form, i.e., free from other peptides (of whatever origin) having a significant effect on the bioactivity of the peptide(s) of this invention. This is not essential, however, as in many utilities peptides of this invention can be used satisfactorily (in many cases, even advantageously) in mixtures or other combinations with different peptides, e.g. other animal growth factors such as bovine (or other animal) IGF-I, EGF or TGF-α (alpha-transforming growth factor). The DNA As used herein with reference to such DNA, the term "synthetic" means it has been made by any technique other than its natural replication in a living animal. Utilizing the nucleotide sequences described herein, any DNA of this invention can be prepared by various techniques well known in the art, e.g. automated DNA synthesizing equipment, other chemical synthesis procedures, cDNA or cloning in a microorganism. Any ,suitable technique can be used. As used herein, the term "containing a] sequence of nucleotides" means that the recited nucleotides are present in such DNA without intervening non-translated nucleotides (e.g. introns). Since the naturally-occurring DNA for bIGF-II contains such intervening untranslated nucleotides, the DNA of this invention containing nucleotide sequences lacking any of such untranslated nucleotides are ipso facto "synthetic." The term "essentially pure", when used herein to describe nucleic acid (DNA or RNA) sequences or molecules, means substantially free from nucleic acid sequences with which the described sequence or molecule is normally associated in its natural state. For purposes of this invention, DNA fragments coding for the mature bIGF-II peptide, a precursor including a leader sequence containing 24 amino acids, and 68 of 89 amino acids of a carboxy extension (E domain) have been isolated and sequenced. As described in Example 4, essentially pure DNA fragments coding for these peptides were isolated from bovine kidney genomic DNA. Analysis of these fragments revealed the following DNA sequence and corresponding amino acid sequence for a bIGF-II precursor protein: ##STR2## The foregoing underlined DNA sequence and corresponding amino acid sequence are those of mature bIGF-II as identified for purposes of the present invention. As shown in the above bIGF-II precursor peptide sequence, three possible translation start-signal codons (ATG's) are in-frame with the DNA sequence coding for mature bIGF-II. It is believed that the first of those ATG's constitutes the operable start of translation for the bIGF-II precursor, but certain host cells may recognize one of the alternative in-frame translation start-signal codons, thereby giving rise to a bIGF-II precursor having an alternative (shorter) leader sequence. If desired, such shortened precursor peptides can be produced by other means, e.g. by using synthetic DNA of this invention beginning with one of the alternative ATG translation start-signal codons. Further, the gene fragments isolated and sequenced in the present invention revealed an E domain (carboxy-terminal extension) for another precursor of the mature bIGF-II peptide. This extension and the DNA coding for it were found to have the following sequences: ##STR3## The discovery and isolation of the DNA sequence for bIGF-II are significant as they not only verified the amino acid sequence determined for purified bIGF-II but provided the DNA sequences and corresponding amino acid sequences for the bIGF-II leader peptide, and carboxy-terminal peptide extension (E domain). Further, the novel DNA sequences of this invention enable those skilled in the art to identify, isolate and/or provide other bIGF-II precursor proteins and/or biologically active fragments thereof including, but not limited to, other peptides having bIGF-II-like activity. The biological activities of these peptides, fragments thereof and products containing same can include, but are not limited to, the growth- and/or lactation-promoting activities of bIGF-II described herein, and can be ascertained in accordance with herein-described or other in vitro and/or in vivo assays. These biologically active fragments and products are herein referred to as "IGF-II gene-related proteins" and include peptides at least a portion of which is encoded in DNA of this invention, allelic variations thereof and/or DNA that hybridizes to DNA of this invention. Having been derived using DNA of this invention or such variations, those IGF-II gene-related proteins are within the scope of this invention. The DNA sequences and genes of the present invention now enable those skilled in the art to more effectively study and/or control IGF-II biosynthesis and biological regulations. Additionally, DNA sequences of this invention can be employed by those skilled in the art to identify and isolate other IGF DNA sequences, IGF genes and IGF gene-related peptides in other species such as, but not limited to, ovine, caprine porcine and avian IGF's, wherein sufficient DNA sequence and/or peptide homology exists. The discovery of the aforementioned leader (signal) sequence enables construction of DNA vectors for production of bIGF-II-like peptides in eucaryotic cells (e.g. mammalian cells and yeast) capable of recognizing and removing the signal sequence, or bIGF-II precursor peptides containing the signal peptide and/or E domain in procaryotic hosts such as bacteria. A preferred method for producing the synthetic peptides of the present invention is by rDNA technology utilizing host cells such as bacteria (e.g. E. coli) or eucaryotic cells such as yeast. Modifications of these DNA sequences herein can be made to affect their efficiency of peptide production in a desired host cell. Such modifications include, but are not limited to, host-preferred codon substitution, construction of DNA coding for fusion proteins including a peptide of this invention, substitution of codons to eliminate or enhance mRNA structural features affecting their translation, and other modifications that improve production of such peptides in the selected host cell. The peptides so produced which exhibit biological activity of the purified bIGF-II described herein in substantial measure are to be considered equivalents of the peptides of this invention. The following examples illustrate specific embodiments of the invention. They are not to be taken as limiting the invention's scope in any way. Various modifications will be apparent to those skilled in the art, with or without the other disclosure herein. All temperatures are in degrees Celsius unless otherwise stated. EXAMPLE I As described in this example, the complete amino acid (AA) composition and sequence of bIGF-II were determined from that peptide isolated and purified from adult bovine serum obtained from Sigma Chemical Co. (St. Louis, Mo.). Partially purified fractions of such bIGF-II were obtained using a combination of isolation procedures described by Svoboda et al. and Zumstein et al. The complete purification of bIGF-II essentially free from other bovine peptides was achieved by reverse phase high performance liquid chromatography (HPLC). All HPLC procedures were accomplished using trifluoroacetic acid (TFA) and acetonitrile. The solvents were delivered to the column at 2 ml/min using a Perkin-Elmer (Norwalk, Conn.) Series 4 HPLC pumping system, and the peptide was visualized using a Hewlett Packard (Greenly, Conn.) 1040A UV/VIS detector. All chromatographic procedures were carried out at ambient room temperatures (23°-28°). The bIGF-II used for the initial sequence determination was prepared using a Chromega fluorodecyl 4.1×250 mm column (E.S. Industries, Marlton, N.J.). Elution of bIGF-II from the Chromega column was accomplished using a linear gradient of acetonitrile from 15-50% (v/v) over 35 min with the TFA concentration maintained at 40 mM. The bIGF-II samples used for complete structural verification were prepared using a Nucleosil C-18 4.1×250 mm column (Altech Associated, Deerfield, Ill.). The solvent system employed for separation on the column was a linear acetonitrile gradient from 30-35% (v/v) over 15 minutes with a constant TFA concentration of 20 mM. Identification of the active bIGF-II was made using the rat placenta radioreceptor assay described in Daughaday et al. This assay also provided an estimate of the quantity of bIGF-II in the final samples. The HPLC-purified bIGF-II was subjected to AA sequence analysis using an Applied Biosystems, Inc. (Foster City, Calif.) Protein Sequencer Model 470A according to the methods described by Hunkapiller et al. (1983a and b). Briefly, 2.5 nanomoles of the HPLC-purified bIGF-II were lyophilized and analyzed on that Sequencer employing an Edman degradation reaction consisting of derivatizing the N-terminal AA with a reagent followed by cleavage of that AA and ultimate release as its phenylthiohydantoin (PTH) derivative. Since N-terminal sequence analysis was unable to provide the complete structure for the peptide, the purified IGF-II was derivatized and enzymatically hydrolyzed using the following procedure: After purification, 75 mg bIGF-II was subjected to performic acid oxidation using the procedure of Hirs for denaturation by converting sulfhydryls to cysteic acid residues. The peptide was dissolved in 50 ml 88% formic acid (Fisher Scientific, Springfield, N.J.) and the solution cooled to 0°. After one hour at room temperature, 5 ml of the performic acid reagent (0.5 ml 30% H 2 O 2 (Fisher Scientific) in 9.5 ml 88% formic acid) was added to the peptide solution. The resulting mixture was allowed to stand at 10° while progress of the reaction was followed using the second reverse phase HPLC procedure specified. On completion (after 45 min), 4 ml water was added to the mixture and the reagents were removed in vacuo using a Speed Vac Concentrator (Savant Instruments, Farmingdale, N.Y.). The residue remaining after solvent removal was dissolved in 1 M NaHCO 3 containing 1 mM CaCl 2 (both Fisher Scientific). The enzymatic hydrolysis was initiated by adding 2 ml of a 0.1 M HCl/2 mM CaCl 2 solution containing 8 mg/ml alpha-chymotrypsin (Sigma Chemical Co.) (16 mg protein added). After 45 min at room temperature, the chymotrypsin was removed using a Centricon-10 (Amicon Corp., Danvers, MA) ultrafiltration device. The filtrate (O-IGF-II chymotryptic hydrolysate) was subjected to reverse phase chromatography using the Nucleosil column and the 20 mM TFA/acetonitrile solvent previously specified. Eluting the column with a linear gradient of acetonitrile from 10 to 70 % (v/v) over 30 min resolved the hydrolysate into 10 major peptide-containing peaks. Sequence analysis of the peptides (performed as above on Model 470A Sequencer in conjunction with an Applied Biosystems Inc. Model 120A PTH Analyzer) from 3 isolated peaks showed that 2 of them contained the AA's required to complete the primary structure elucidation for bIGF-II. TABLE II shows the N-terminal sequence analysis of the peak HPLC material together with the published sequences for human and rat IGF-II's. Residues 1-43 of the bIGF-II were determined by N-terminal sequence analysis of the purified bIGF-II. Residues 37-59 and 60-67 were determined by N-terminal sequence analysis of the two separate chymotryptic fragments. Molar cysteic acid content of the peptides was verified using precolumn orthophthalaldehyde AA analysis as described in Larsen et al. As shown in TABLE II, three differences were found between the bovine and human sequences and three differences were found between the bovine and rat sequences. TABLE II__________________________________________________________________________IGF-II Amino Acid Sequences__________________________________________________________________________ ##STR4##HumanNH.sub.2AlaTyrArgProSerGluThrLeuCysGlyGlyGluLeuValAspThrLeuGlnPheRatNH.sub.2AlaTyrArgProSerGluThrLeuCysGlyGlyGluLeuValAspThrLeuGlnPhe ##STR5##HumanValCysGlyAspArgGlyPheTyrPheSerArgProAlaSerArgValSerArgArgRatValCysSerAspArgGlyPheTyrPheSerArgProSerGly/Ser ArgAlaAsnArgArg ##STR6##HumanSerArgGlyIleValGluGluCysCysPheArgSerCysAspLeuAlaLeuLeuGluThrRatSerArgGlyIleValGluGluCysCysPheArgSerCysAspLeuAlaLeuLeuGluThr ##STR7##HumanTyrCysAlaThrProAlaLysSerGluCOOHRatTyrCysAlaThrProAlaLysSerGluCOOH__________________________________________________________________________ The bIGFII residues with an asterisk differ from the corresponding residues in human IGFII. The underlined bIGFII residues differ from the corresponding residues in rat IGFII. EXAMPLE II This example demonstrates the activity of bIGF-II in the rat L6 myoblast proliferation assay. Specifically, the peak HPLC material of Example I was compared to a commercial preparation of human IGF-I from Amgen Inc. (Thousand Oaks, Calif.) for demonstrable physiological activity in that assay. Rat L6 myoblasts described by Yaffee were used as described by Kotts. All incubations were carried out at 37° , 10% CO 2 , and 100% humidity. A Coulter Counter (Model ZM) equipped with a C-1000 Channelyzer (Coulter Electronics, Hialeah, FL) was used for cell counting. Stock cultures were maintained in Dulbecco's Minimum Essential Medium (DMEM) (Grand Island Biological Corp. (GIBCO), Grand Island, N.Y.) containing 10% (v/v) fetal calf serum (FCS medium) and routinely plated at 1200 cells/cm 2 or 600 cells/cm 2 and passaged after 3 or 4 days, respectively, in culture. Passaging was performed by adding 3 ml of 0.05% (w/v) trypsin (GIBCO) in wash buffer (0.8% (w/v) NaCl, 0.04% (w/v) KCl, 0.1% (w/v) dextrose, 0.058% (w/v) NaHCO 3 , 0.02% (w/v) EDTA, pH 7.4) for 5 minutes at 37° and trypsinization was stopped by adding 7 ml FCS media. Test cultures were prepared as follows: Stock cultures were trypsinized and pooled and the resulting cell suspension was counted. Based on this count, cells were diluted to the appropriate concentration in FCS media and rapidly plated in 25 cm 2 flasks at a density of 600/cm 2 . 24 hours after plating, the media was removed and cells were rinsed with serum-free DMEM. Test media (4 ml) was then applied to each flask and incubation was carried out for an additional 24 hours after which the culture medium was replaced with fresh test medium. Cultures were then incubated for another 48 hours and counted. For counting, the test media was removed, cells were rinsed with 2 ml of wash buffer, 1 ml of trypsin solution was added and the cells were incubated for 5 minutes at 37°. The reaction was stopped by addition of 3 ml of cold FCS media. Flasks were pounded 10 times to facilitate cell removal and tipped upright in an ice bath until their contents could be transferred to glass tubes on ice. Each flask was rinsed with 2-3 ml of cold 0.9% (w/v) NaCl and the rinse was added to the cell suspension. Each tube was vortexed gently 5 times to eliminate clumping of cells and the contents of each tube were counted using a Coulter Counter. Test media for application to the test cultures was prepared by diluting the test sample to the desired concentration with 2% (v/v) FCS medium. The lyophilized peak HPLC material of Example I was dissolved in 30 mM Tris-HCl, pH 7.4 (Tris buffer) to an estimated concentration of 2.6 μM. In Test 1, 0.2 ml of this solution was added to 19.8 ml 2% FCS (26 nM final conc.), filter-sterilized through a 0.22μ filter (Millipore Corp., Bedford, Mass.) and applied to the experimental cultures. A control containing 0.2 ml of the Tris buffer was included for comparison. In Test 2, 0.2 ml of the solution of HPLC material was added to 9.8 ml of 2% (v/v) FCS (estimated 52 nM final conc.), filtered as above, and applied to the experimental cultures. A control containing Tris buffer was prepared similarly. The positive control for each treatment was 10 -9 M human IGF-I (Amgen Biologicals, Thousand Oaks, Calif.). See Kotts et al. The lyophilized IGF-I was diluted with 44 mM NaHCO 3 , pH 7.4 to a concentration of 100 pg/ml. A 10 -8 M stock solution was prepared by adding 0.015 ml IGF-1 to 20 ml of 2% (v/v) FCS medium. For 10 -9 M, 2 ml of this stock was added to 18 ml of 2% FCS medium, filter-sterilized and applied to experimental cultures. The control for these cultures was 2% (v/v) FCS medium. In Test 3, peak HPLC material from Example I was dissolved in 20% acetic acid to an estimated concentration of 165 μM. Two stock media solutions were prepared. A 0.5 μM stock was prepared by adding 0.091 ml of 165 μM solution to 30 ml 2% FCS. pH was adjusted to 7.4 by adding 60 μl of 10% NaOH. A 0.1 μM stock was prepared by adding 0.018 ml of 165 μM solution to 30 ml 2% FCS. pH was then adjusted to 7.4 by adding 10 μl of 10% NaOH. These stock media solutions were filter sterilized and used to prepare serial (1:10 v/v) dilutions. For each serial dilution, 3 ml of the appropriate solution was added to 27 ml 2% FCS. Four controls were prepared. Control A contained 0.091 ml 20% acetic acid in 30 ml 2 % FCS; pH was adjusted to 7.4 by adding 60 μl of 10% NaOH. Control B contained 0.018 ml 20% acetic acid in 30 ml 2% FCS; pH was adjusted to 7.4 by adding 10 μl of 10% NaOH. Control C contained 3 ml of Control A and 27 ml 2% FCS. Control D contained 30 ml 2% FCS. Control A was used for the 500 nM bIGF-II test, Control B for the 100 nM bIGF-II test, Control C for the 50 nM bIGF-II test and Control D for the 10 nM, 5 nM, 1 nM, 0.5 nM and 0.1 nM bIGF-II tests. As shown in TABLE III, bIGF-II significantly stimulated L6 myoblast proliferation at the treatment concentrations tested. TABLE III______________________________________bIGF-II Cells/Cm.sup.2 Std.Treatment Conc..sup.a Mean Dev.______________________________________Test 1Tris Buffer -- 11508 11778 11643 ±135bIGF-II 26 nM 13401 12953 13177 ±224hIGF-I 1 nM 15519 15752 15635 ±1162% FCS -- 12313 12691 12502 ±189mediumTest 2Tris Buffer 8301 -- --bIGF-II 52 nM 10156 -- --hIGF-I 1 nM 10869 11004 10731 10868 ±792% FCS -- 8930 9676 9109 9252 ±121medium______________________________________ TABLE III______________________________________Test 3 Cells/cm.sup.2 Std.Treatment Conc..sup.a Mean Dev.______________________________________Control A -- 6391 6306 6039 6245 150bIGF-II 500 nM 11401 11223 10948 11191 186Control B -- 6558 -- -- 6558 --bIGF-II 100 nM 14037 13505 13905 13816 226Control C -- 8138 8383 8276 8266 100bIGF-II 50 nM 12374 11781 12488 12214 310Control D -- 9596 8836 8338 8923 517bIGF-II 10 nM 12175 11630 11348 11718 343bIGF-II 5 nM 11414 11239 10871 11175 226bIGF-II 1 nM 9916 9380 9420 9572 244bIGF-II 0.5 nM 8739 9135 9030 8968 167bIGF-II 0.1 nM 8754 8885 8697 8779 79hIGF-I 1 nM 11419 10653 10857 10976 324 10 nM 13676 13335 13926 13646 242______________________________________ .sup.a Estimated by radioimmunoassay or area under HPLC peak. EXAMPLE III This example demonstrates the ability of bIGF-II to stimulate bovine mammary epithelial cell proliferation. Specifically, bIGF-II purified as in Example I was tested in a collagen gel culture system for its ability to stimulate such proliferation. Mammary tissue from a 150-200 day pregnant, non-lactating Holstein cow was obtained at slaughter. Tissue was minced and placed in a 500 ml fluted Erlenmeyer flask containing 0.15% (w/v) collagenase (Batch #103-586; Boehringer Mannheim, Indianapolis, Ind.), 0.1% (w/v) hyaluronidase (Type 1, Sigma Chemical Co.), plus 5% (v/v) fetal bovine serum (FBS) in Medium 199 (both GIBCO). 90 ml of total solution was used per 5 gms of tissue. The dispersing solution was swirled on a gyrotory water bath at 60 rpm at 35° for 4-5 hours or until most clumps were dispersed. To remove large fragments, dispersed tissue, mixed with 0.02% (w/v) DNase, deoxyribonuclease I (Sigma Chemical Co.) was filtered through Nitex cloth (mesh size 153 μm, Tetko Co., Elmsford, N.Y.). Undigested clumps were collected and resuspended in 0.05% (w/v) pronase (Calbiochem-Behring Corp., LaJolla, Calif.) and swirled at 40 rpm at 35° for an additional 15 min. Mammary tissue was again filtered, collected by centrifugation, washed with Medium 199 and held on ice until density gradient separation. Following enzyme dissociation, mammary fragments were resuspended in 1 ml of 0.02% DNase and layered on a preformed gradient of Percoll (Pharmacia Fine Chemicals, Piscataway, N.J.), as described in Richards et al. Briefly, 30 ml of 42% Percoll were centrifuged at 20,000×g for 1 hour to generate a continuous gradient. Approximately 3×10 7 cells were layered on top of this gradient and centrifuged for 10 min at 800×g. Epithelial organoids were collected from the 1.065-1.070 g/ml region of the gradient. Cell number estimates prior to culture were made by mixing one volume of cell suspension with nine volumes of 0.2% (v/v) crystal violet in 0.1 M citric acid. Stained nuclei were counted on a hemocytometer. Basic techniques for the collagen gel culture system are described in Yang and Nandi. Collagen gel was prepared as described in Michalopoulos et al. with slight modification (Richards et al.). Briefly, 4 g sterilized rat tail collagen fibers (predominantly Type 1) were dissolved in 1 liter of sterile 0.017 M acetic acid at 4° for 48 hours. After centrifugation at 10,000×g for 60 min, the supernatant was collected and this served as the stock collagen solution. Each batch of collagen was individually titrated to pH 7.4, using solutions of 10X Medium 199 (no bicarbonate) (GIBCO) and 0.34 N NaOH in a ratio of 2:1. For culturing cells within the collagen matrix, the neutralized collagen mixture was kept on ice to prevent gelation. Epithelial organoids in a minimal volume (0.5 ml) of Medium 199 were added yielding a final concentration of 4-6×10 5 cells/ml gelation mixture. The collagen-cell suspension (0.5 ml) was overlaid on 0.3 ml of pregelled collagen in each well of a 24 well plate (Costar, Cambridge, Mass.) and allowed to gel at room temperature. After this layer gelled, cultures were fed with 0.5 ml of a 1:1 mixture of Dulbecco's Modified Eagle's (DME):Hams F-12 (DME/F-12) (GIBCO) plus 3% (v/v) FBS, 10 ng/ml mouse epidermal growth factor (EGF) (Collaborative Research, Inc., Waltham, Mass.), antibiotics (GIBCO), and the appropriate test growth factor. Cultures were incubated at 37° in 95% air-5% CO 2 and the culture medium was changed every other day. As shown in TABLE IV, the ability of bIGF-II to stimulate bovine mammary epithelial cell proliferation in the collagen gel assay system was tested in triplicate over a broad concentration range. A negative proliferation control, Basal Medium [DME/F-12+3% (w/v) FCS +EGF (10 ng/ml)], and positive proliferation controls, containing insulin at various supraphysiological concentrations, were simultaneously run. As shown in TABLE IV, bIGF-II stimulated bovine mammary epithelial cell proliferation at a statistically significant level at concentrations ranging from about 30 nM to about 100 nM. TABLE IV__________________________________________________________________________Test 1 Cell Numbers/Well (× 10.sup.4) Std. % IncreaseTreatment Conc. Mean Dev. Over Control__________________________________________________________________________bIGF-II 0.1 nM 29.5 28.8 19.9 26.1 5.4 -- 1.0 nM 30.1 24.4 29.4 27.9 3.1 -- 3.3 nM 29.0 22.4 18.6 23.3 5.3 -- 10.0 nM 35.6 41.3 38.4 38.4 2.9 30.2 33.0 nM 42.2 46.4 -- 44.3 2.9 50.2 100.0 nM 57.8 57.1 58.7 57.8 0.8 95.9Insulin 17.0 nM 31.5 35.9 34.7 34.1 2.3 15.6 170.0 nM 51.2 45.4 57.4 51.4 6.0 74.2 1700.0 nM 38.7 56.9 68.5 54.7 15.0 85.4Control.sup.a 29.4 29.7 -- 29.5 0.25 --__________________________________________________________________________ .sup.a Basal Medium In Test 2, peak HPLC material from Example I was dissolved in 20% acetic acid to an estimated concentration of 165 μM and added directly to the same Basal Medium to form two stock solutions. Stock solution 1 contained 33.6 μl of bIGF-II solution+11.1 ml Basal Media (final conc. bIGF-II =500 nM). Stock solution 2 contained 6.7 μl of bIGF-II solution+11.1 ml Basal Media (final conc. bIGF-II=100 nm). Serial dilutions were made from these stocks and tested over a concentration range of 0.1 nM to 100 nM. Control media consisted of Basal Medium plus a corresponding volume of acetic acid if necessary (an appropriate control was necessary when the growth factor addition lowered pH of the test media). All media was adjusted to neutral pH by addition of 10% NaOH. TABLE 2______________________________________ % IncreaseIGF-II Con- Cell Numbers/Well (× 10.sup.4) Std. OverConc. trol.sup.a Mean Dev. Control______________________________________100 nM 2 37.9 43 34.8 38.6 4.1 94.0%50 nM 3 35.9 38.9 37.9 37.5 1.5 76.1%10 nM 1 33.8 39.9 38.9 37.5 3.3 30.6%5 nM 1 34.8 29.8 39.9 34.8 5.1 21.2%1 nM 1 33.8 33.8 35.9 34.5 1.2 20.2%.5 nM 1 22.7 25.7 30.8 26.4 4.1 --0.1 nM 1 26.7 29.8 -- 28.2 2.1 --Controls1 29.8 31.8 24.7 28.7 3.7 --2 21.6 18.6 19.6 19.9 1.6 --3 19.6 24.7 19.6 21.3 2.9 --______________________________________ .sup.a Appropriate Control 1 = Basal Medium 2 = Basal Medium + 33.6 μl 20% Acetic Acid; pH adjusted to 7.4 with 10 NaOH 3 = Basal Medium + 6.7 μl 20% Acetic Acid; pH adjusted to 7.4 with 10% NaOH EXAMPLE 4 Restriction and DNA modifying enzymes used in the procedures described herein were from New England Biolabs (Beverly, Mass.). Except as specifically noted, the cloning and sequencing steps employed standard molecular biology procedures as described and/or referenced in Maniatis et al. (Maniatis). Genomic DNA was isolated from calf kidney as described in Maniatis, pp. 280-281. The DNA probes used in the genomic Southern analysis and screening of the bovine genomic library described below were isolated as follows: A human IGF-II cDNA clone structurally of a kind published by Bell et al. and Dull et al. was obtained as a 1.7 kilobase pair (kbp) Eco RI fragment containing the cDNA diagrammed in FIG. 1, and cloned into the plasmid vector pUC18. The insert DNA was purified away from vector sequences by digestion with the restriction enzyme Eco RI followed by size-fractionation via electrophoresis through 0.7% w/v agarose (Maniatis, pp. 150-161). The DNA was stained with ethidium bromide (1 μg/ml), visualized under long-wave UV light, and the 1.7 kbp band was excised. DNA was recovered by electroelution (Maniatis, p. 164) and further purified over elutip columns (Schleicher and Schuell, Keene, N.H.) according to the supplier's recommendations. This 1.7 kbp fragment was digested further with the restriction enzyme Rsa I to obtain the fragments diagrammed in FIG. 1. Each of these fragments was purified as described above for the 1.7 kbp fragment (Maniatis, pp. 150-164). The 340 and 515 bp fragments, believed to include the entire coding sequence for the human IGF-II prepeptide, were used in the genomic Southern analysis and screening of a bovine genomic library described below. ##STR8## From the A and B regions of hIGF-II shown in Dull et al., there were designed two synthetic oligomers which are herein designated IGF-IIA and IGF-IIB, respectively, and shown in FIG. 2. __________________________________________________________________________FIG. 2__________________________________________________________________________IGF-IIA48 49 50 51 52 53 54 55 56 57 58AA Phe Arg Ser Cys Asp Leu Ala Leu Leu Glu Thrhuman 5'TTC CGC AGC TGT GAC CTG GCC CTC CTG GAG ACG 3'probe 3'AAG GCG TCG ACA CTG GAC CGG GAG GAC CTC TG 5'1GF-11B| 1 2 3 4 5 6 7 8 9 10 11 12AA Ala Tyr Arg Pro Ser Glu Thr Leu Cys Gly Gly Gluhuman 5'GCT TAC CGC CCC AGT GAG ACC CTG TGC GGC GGG GAG 3'probe 3'CGA ATG GCG GGG TCA CTC TGG GAC ACG CCG CCC C 5'__________________________________________________________________________ These oligomers were synthesized on an Applied Biosystems, Inc. (Foster City, Calif.) DNA synthesizer Model 380 A or B. The oligomers were used to identify small subclones of the genomic clone which contained exon sequences, and in the case of IGF-IIB, as a primer for DNA sequencing. Genomic blots of bovine kidney DNA were done using a modification of the method of Southern. In that modification, 20 μg bovine kidney DNA was digested with Eco R1, Bam HI or Hind III, fractionated on a 20×13.5 cm 0.7% (w/v) agarose gel, stained with ethidium bromide (1 μg/ml) and photographed. The DNA was denatured for two hours at 37° in 0.5 N NaOH/1.5 M NaCl, neutralized for an additional two hours at 37° in 0.5 M Tris-HCl(pH 8)/1.5 M NaCl, and transferred overnight onto Schleicher and Schuell nitrocellulose filters in 10X SSPE (lX SSPE is 180 mM NaCl, 10 mM sodium phosphate, pH 6.8, 1 mM EDTA, all from Sigma Chemical Co.). A sponge was used instead of a paper wick. The filters were washed briefly in 10X SSPE, air-dried, baked for 2-3 hours at 80° in a vacuum oven and soaked for one hour at 50° in 5X SSPE. Denhardt's was added to a final concentration of 5X (lX Denhardt's is 0.02% w/v bovine serum albumin, 0.02% Ficoll, 0.02% polyvinyl pyrrolidone, all from Sigma Chemical Co.) and the filters were soaked an additional hour. The blots were prehybridized overnight at 37° in 25 ml of a mixture containing 50% (v/v) formamide; 5X SSPE; 5X Denhardt's; 0.1% (w/v) SDS (sodium dodecyl sulfate); and 100 μg/ml each of carrier salmon testes (ST) DNA and yeast tRNA. Prior to addition, the ST DNA and tRNA were denatured by boiling for 10 minutes. Probes were radiolabelled by nick translation (Maniatis, p. 109) to a specific activity of 10 7 -10 8 dpm/μg. Between 10; and 3×10 8 dpm of the appropriate nick-translated probe was added to the prehybridization mixture, which was then incubated for 48 hours at 42°. The filters were washed twice for 15 min at 42° in 1X SSPE/0.1% SDS, followed by a final wash (10-15 min) at the same temperature in 0.1X SSPE/0.1% SDS. The filters were air dried, and exposed to Kodak XAR film at -70° for 2-3 days with one intensifying screen. Results of a bovine genomic Southern analysis carried out with the 340 bp and 515 bp nick-translated probes (FIG. 1) are in TABLE V. TABLE V______________________________________Length of Band (kbp) 340 bp Probe 515 bp Probe______________________________________Eco RI 4.4 4.4BAM HI 6.0 8.2HIND III 13.5 13.5______________________________________ The length of each hybridizing band was determined by measuring the distance of the band from the top of the gel compared to standard DNA's of known length electrophoresed on the same gel. Results indicated that the entire coding sequence of bIGF-II could be found on a 4.4 kbp Eco RI fragment. A genomic library containing Eco RI fragments of approximately this size was constructed as follows: Bovine kidney DNA was digested to completion with Eco RI and size-fractionated by electrophoresis through agarose as described above. DNA fragments 3.8 kbp to 4.8 kbp in length were excised from the gel and purified by electroelution (Maniatis, p. 164) followed by elutip column chromatography (Schleicher and Schuell). 100 nanograms of this size-selected DNA was ligated into the vector lambda gt10 from Vector Cloning Systems (San Diego, Calif.). This vector is used to clone Eco RI cut DNA fragments ranging in size between zero and seven kbp. It was obtained pre-cut with Eco RI and ready to be ligated. Ligation was carried out using standard conditions (Maniatis, p. 286). The resulting ligated DNA was packaged in vitro using Vector Cloning Systems packaging extracts. The titer of the library obtained was 1.5×10 7 plaque forming units (pfu) per μg of DNA ligated. Screening of the library was carried out as follows: 1.2×10 5 pfu were plated on C600 cells as described in Maniatis, p. 320. The phage were plated at a density of 4000 pfu per 100 cm 2 plate containing NZC Agar (NZC is 10% w/v NZ amine, 0.5% w/v NaCl, 0.2% w/v MgCl 2 and 0.1% w/v casamino amino acids, all from Sigma Chemical Co.). Plates were incubated overnight at 37°, chilled at 4° for several hours, and transferred to nitrocellulose as described in Maniatis, p. 320. Hybridization to the nick-translated 340 bp and 515 bp probes was carried out as described above for Southern genomic blots. Positive clones were selected and subjected to a second round of screening identical to the first round, with the exception that the phage density was reduced to 100-200 pfu/100 cm 2 plate. Positive clones from the second screen were plated out a third time as described, except that the phage density was reduced further to 20-50 pfu/100 cm 2 plate. Well-isolated positive clones from the third round of screening were picked and purified DNA was prepared from these plaques according to Maniatis, p. 76. The inserts were released from the lambda gt10 arms by Eco RI digestion and subcloned into pUC18 (New England Biolabs), to provide a convenient source of large amounts of the insert DNA. Plasmid DNA was prepared as described in Maniatis, p. 90. To prepare fragments of DNA containing exon sequences which were of a convenient length for DNA sequencing (less than 500 bp) the following procedure was employed: The insert DNA was digested with the restriction endonucleases Alu 1, Hae III, Pst I or Sau 3A. These digestions produce random DNA fragments of sequenceable length. Each digest was ligated at random into the sequencing vectors M13mp18 and M13mp19 from New England Biolabs. The resulting plaques, obtained after transformation into JM101 cells (Maniatis, p. 250, and Messing et al.) were screened by hybridization to either the IGF-IIA or IGF-IIB oligomers to identify the desired clones containing exon sequences. For these hybridizations the synthetic oligomers were end-labelled as described in Maniatis, p. 122. The prehybridization buffer was altered to exclude the formamide, and the concentrations of SSPE and Denhardt's were increased to 6X and 10X, respectively, as in Meinkoth et al. Hybridization was carried out at 30°-37° and the washing temperature was reduced to 37°. Filters were washed for shorter times (5-10 minutes) in 6X SSPE/0.1% SDS. DNA was prepared from plaques hybridizing to either probe as in Messing et al. The purified, single-stranded DNA was sequenced using the dideoxy technique described in Sanger et al, except that sulfur-35 labelled nucleotides (Amersham Corp., Arlington Heights, Ill.) were used in place of the P-32 nucleotides described in Sanger et al. Exon/intron junctions were identified using three criteria: Open reading frames, exon/intron junction sequences and analogy to the human cDNA sequence. In the following sequences, the identified exon/intron junctions are shown by underlining the two (adjacent) nucleotides on either side of each junction. By such sequencing, the nucleotide sequence coding for the mature bIGF-II peptide was found to be: ##STR9## Also determined by the foregoing procedure was the following DNA sequence coding for bIGF-II linked directly at its amino end to a leader of 24 additional amino acids: ##STR10## Another sequence determined by the foregoing procedure was that of the following DNA coding for mature bIGF-II linked directly at its carboxy end to an extension of 68 amino acids. ##STR11## By the foregoing procedure, there was also determined the following nucleotide sequence of DNA coding for a bIGF-II precursor including the aforedescribed N-terminal leader and C-terminal extension: ##STR12## The bIGF-II peptides produced by expression of the immediately preceding three nucleotide sequences have substantially the biological activity of bIGF-II (in general, after removal of the aforementioned leader sequence from those peptides containing same and/or suitable naturation, as required) and can be used instead of the shorter (e.g. 67 AA) peptides of this invention (in some cases advantageously) to provide biological effects like those of bIGF-II in animals. Cited Publications 1. Bala, R. M. and Bhaumick, B. (1979) Can. J. Biochem. 57:1289-98 2. Bell, G. I., Merryweather, J. P., Sanchez-Pescador, R., Stempien, M. M., Priestley, L., Scott, J. and Rall, L. B. (1984) Nature 310:775-77 3. Daughaday, W. H. et al. (1981) J. Clin. Endocrinol. & Metab. 53:282-88 4. Dull, T. J., Gray, A., Hayflick, J. S., and Ullrich, A. (1984) Nature 310:777-81 5. Gospodarowicz, D., Weseman, J., Moran, J. S. and Lindstrom, J. (1976) J. Cell Biol. 70:395-405 6. Hirs, C. H. W. (1956) J. Biol. Chem. 219:611-621 7. Humbel, R. E. (1984) in Hormonal Proteins and Peptides, ed. Choh Hao Li, Academic Press, Inc., XII:66-68 8. Hunkapiller et al. (1983a) Methods in Enzymol., C. H. W. Hirs et al., Eds. (Academic Press, New York, N.Y.) 91:399-413 9. Hunkapiller et al. (1983b) Methods in Enzymol., C. H. W. Hirs et al., Eds. (Academic Press, New York, N.Y.) 91:486-493 10. Kotts, C. E. (1984) Ph.D. Dissertation, Univ. of Minnesota, St. Paul, Minn. 11. Kotts, C. E. and Baile, C. A. (1985) Fed Proc. 44(3):484 12. Larsen, B. R. and West, F. G. (1981) J. Chromato. Sci. 19:259-65 13. Lehninger, A. L. (1976) Biochemistry, 2nd Ed., Worth Publishers, Inc. New York, N.Y., pp. 72-75, 315-322 14. Liberti (1975) Biochem & Biophys. Res. Comm. 67:1226-1233 15. Maniatis, T., Fritsch, E. F. and Sambrook, J. (1982) in Molecular Cloning: A Laboratory Manual (Cold Springs Harbor Laboratory, Cold Springs Harbor, N.Y.) 16. Marquardt, H. et al. (1981) J. Biol. Chem. 256:6859-63 17. Meinkoth, J. and Wahl, G. (1984) Anal. Biochemistry 138:267-84 18. Messing, J., Crea, R. and Seeburg, P. H. (1981) Nucl. Acids Res. 9:4173-88 19. Michalapoulos, G. and Pitot, H. C. (1975) Exp. Cell Res. 94:70-78 20. Richards et al. (1983) J. Tissue Cult. Methods 8:31-39 21. Rinderknecht and Humbel, E. E. (1978) FEBS Letters 89:283-86 22. Sanger, F., Nicklen, S. and Coulson, A. R. (1977) Proc. Natl. Acad. Sci. USA 74:5463-67 23. Southern, E. M. (1975) J. Mol. Biol. 98:503-17 24. Strain, A J., Hill, D. J., Swenne, I., and Milner, R. D. G. (1986) British Endocrine Society Abstracts, Abs #142 25. Svoboda et al. (1980) Biochemistry 19:790-97 26. Van Wyk, J. J. et al. (1975) Adv. Metab. Disorders 8:127-50 27. Woo, S. L. C. (1979) Methods in Enzymol., R. Wu, Ed. (Academic Press, New York) 68:389-95 28. Yaffee, D. (1968) Proc. Nat'l. Acad Sci., U.S.A. 61:477 29. Yang, J. and Nandi, S. (1983) Int. Rev. of Cytol. 81:249-86 30. Yamashiro, D., and Li, C. H. (1985) Int. J. Peptide Protein Res. 26:299-304 31. Zumstein, P. P. and Humbel, R. E. (1985) Methods in Enzymology, L. Bimbaumer et al., Eds. (Academic Press, New York, N.Y.) 109:782-98

This invention relates to novel peptides having utility for promotion of growth and/or lactation in animals, to processes and DNA useful in production of such peptides, and to methods utilizing such peptides to promote growth or lactation in animals. In some embodiments, the invention is directed to peptides having bovine IGF-II biological activity, to production of such peptides, and to their use in effecting proliferation of certain cells (e.g. mammary epithelial or muscle) or in enhancing lactation in cattle or other animals.

TECHNICAL FIELD OF INVENTION [0001] The present invention relates to inhibitors of p38, a mammalian protein kinase involved in cell proliferation, cell death and response to extracellular stimuli. The invention also relates to methods for producing these inhibitors. The invention also provides pharmaceutical compositions comprising the inhibitors of the invention and methods of utilizing those compositions in the treatment and prevention of various disorders. BACKGROUND OF THE INVENTION [0002] Protein kinases are involved in various cellular responses to extracellular signals. Recently, a family of mitogen-activated protein kinases (MAPK) has been discovered. Members of this family are Ser/Thr kinases that activate their substrates by phosphorylation [B. Stein et al., Ann. Rep. Med. Chem., 31, pp. 289-98 (1996)]. MAPKs are themselves activated by a variety of signals including growth factors, cytokines, UV radiation, and stress-inducing agents. [0003] One particularly interesting MAPK is p38. p38, also known as cytokine suppressive anti-inflammatory drug binding protein (CSBP) and RK, was isolated from murine pre-B cells that were transfected with the lipopolysaccharide (LPS) receptor, CD14, and induced with LPS. p38 has since been isolated and sequenced, as has the cDNA encoding it in humans and mouse. Activation of p38 has been observed in cells stimulated by stress, such as treatment of lipopolysaccharides (LPS), UV, anisomycin, or osmotic shock, and by cytokines, such as IL-1 and TNF. [0004] Inhibition of p38 kinase leads to a blockade on the production of both IL-1 and TNF. IL-1 and TNF stimulate the production of other proinflammatory cytokines such as IL-6 and IL-8 and have been implicated in acute and chronic inflammatory diseases and in post-menopausal osteoporosis [R. B. Kimble et al., Endocrinol., 136, pp. 3054-61 (1995)]. [0005] Based upon this finding, it is believed that p38, along with other MAPKs, have a role in mediating cellular response to inflammatory stimuli, such as leukocyte accumulation, macrophage/monocyte activation, tissue resorption, fever, acute phase responses and neutrophilia. In addition, MAPKs, such as p38, have been implicated in cancer, thrombin-induced platelet aggregation, immunodeficiency disorders, autoimmune diseases, cell death, allergies, osteoporosis and neurodegenerative disorders. Inhibitors of p38 have also been implicated in the area of pain management through inhibition of prostaglandin endoperoxide synthase-2 induction. Other diseases associated with Il-1, IL-6, IL-8 or TNF overproduction are set forth in WO 96/21654. [0006] Others have already begun trying to develop drugs that specifically inhibit MAPKs. For example, PCT publication WO 95/31451 describes pyrazole compounds that inhibit MAPKs, and, in particular, p38.However, the efficacy of these inhibitors in vivo is still being investigated. [0007] Accordingly, there is still a great need to develop other potent inhibitors of p38, including p38-specific inhibitors, that are useful in treating various conditions associated with p38 activation. SUMMARY OF THE INVENTION [0008] The present invention addresses this problem by providing compounds that demonstrate strong inhibition of p38. [0009] These compounds have the general formula: [0010] wherein each of Q 1 and Q 2 are independently selected from a phenyl or 5-6 membered aromatic heterocyclic ring system, or a 8-10 membered bicyclic ring system comprising aromatic carbocyclic rings, aromatic heterocyclic rings or a combination of an aromatic carbocyclic ring and an aromatic heterocyclic ring. [0011] A heterocyclic ring system or a heterocyclic ring contains 1 to 4 heteroatoms, which are independently selected from N, O, S, SO and SO 2 . [0012] The rings that make up Q 1 are substituted with 1 to 4 substituents, each of which is independently selected from halo; C 1 -C 3 alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′ or CONR′ 2 ; O—(C 1 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′ or CONR′ 2 ; NR′ 2 ; OCF 3 ; CF 3 ; NO 2 ; CO 2 R′; CONR′; SR′; S(O 2 )N(R′) 2 ; SCF 3 ; CN; N(R′)C(O)R 4 ; N(R′)C(O)OR 4 ; N(R′)C(O)C(O)R 4 ; N(R′)S(O 2 )R 4 ; N(R′)R 4 ; N(R 4 ) 2 ; OR 4 ; OC(O)R 4 ; OP(O) 3 H 2 ; or N═C—N(R′) 2 . [0013] The rings that make UP Q 2 are optionally substituted with up to 4 substituents, each of which is independently selected from halo; C 1 -C 3 straight or branched alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, S(O 2 )N(R′) 2 , N═C—N(R′) 2 , R 3 , or CONR′ 2 ; O—(C 1 -C 3 )-alkyl; O—(C 1 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, S(O 2 )N(R′) 2 , N═C—N(R′) 2 , R 3 , or CONR′ 2 ; NR′ 2 ; OCF 3 ; CF 3 ; NO 2 ; CO 2 R′; CONR′; R 3 ; OR 3 ; NR 3 ; SR 3 ; C(O)R C(O)N(R′)R 3 ; C(O)OR ; SR′; S(O 2 )N(R′) 2 ; SCF 3 ; N═C—N(R′) 2 ; or CN. [0014] Q 2 ′ is selected from phenyl or a 5-6 member aromatic heterocyclic ring optionally substituted with 1-3 substituents, each of which is independently selected from halogen; C 1 -C 3 alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, CONR′ 2 , or O—P(O 3 )H 2 ; O—(C 2 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, CONR′ 2 , or OP(O 3 )H 2 ; OCF 3 ; CF 3 ; OR 4 ; O—CO 2 R 4 ; O—P(O 3 ) H 2 ; CO 2 R′; CONR′; SR′; S(O 2 )N(R′) 2 ; SCF 3 ; CN; N(R′)C(O)R 4 ; N(R′)C(O)OR 4 ; N(R′)C(O)C(O)R′; N(R′) S(O 2 ) R 4 ; N(R′) R 4 ; N(R 4 ) 2 ; OR 4 ; OC(O)R 4 ; OP(O) 3 H 2 ; or N═C—N(R′) 2 ; provided that Q 2 ′ is not phenyl optionally substituted 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl. [0015] R′ is selected from hydrogen; (C 1 -C 3 )-alkyl; (C 2 -C 3 )-alkenyl or alkynyl; phenyl or phenyl substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl; or a 5-6 membered heterocyclic ring system optionally substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl. [0016] R 3 is selected from 5-8 membered aromatic or non-aromatic carbocyclic or heterocyclic ring systems each optionally substituted with R′, R 4 , —C(O)R′, —C(O)R —C(O)OR 4 or —J; or an 8-10 membered bicyclic ring system comprising aromatic carbocyclic rings, aromatic heterocyclic rings or a combination of an aromatic carbocyclic ring and an aromatic heterocyclic ring each optionally substituted with R′, R 4 , —C(O)R′, —C(O)R 4 , —C(O)OR or —J. [0017] R 4 is (C 1 -C 4 )-straight or branched alkyl optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2) 2 ; or a 5-6 membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 . [0018] R 5 is selected from hydrogen; (C 1 -C 3 )-alkyl optionally substituted with R 3 ; (C 2 -C 3 )-alkenyl or alkynyl each optionally substituted with R 3 ; phenyl or phenyl substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl; or a 5-6 membered heterocyclic ring system optionally substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl. [0019] W is selected from N(R 2 ) SO 2 —N(R 2 ) 2 ; N(R 2 )SO 2 —N(R 2 )(R 3 ); N(R 2 )C(O)—OR 2 ; N(R 2 )C(O)—N(R 2 ) 2 ; N(R 2 )C(O)—N(R 2 )(R 3 ); N(R 2 )C(O)—R 2 ; N(R 2 ) 2 ; C(O)—R 2 ; CH(OH)—R 2 ; C(O)—N(R 2 ) 2 ; C(O)—OR 2 ; J; or (C 1 -C 4 ) straight or branched alkyl optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , R 3 , SO 2 N(R 2 ) 2 , OC(O)R′, OC(O)R′, OC(O)N(R′) 2 , —N(R′)(R 5 ), —C(O)N(R 5 )(R 2 ), —C(O)R′, —N(R 2 )C(O)N(R 2 )(R 5 ), —NC(O)OR 5 , —OC(O)N(R 2 )(R 5 ), or —J; a 5-6 membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R′) 2 ; or a 8-10 membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 ; provided that W is not an R 3 substituted C 1 alkyl. [0020] W′ is selected from N(R 2 )—SO 2 —Q 2 ; N(R 2 )—CO 2 —Q 2 ; N(R 2 )—C(O)—Q 2; N(R 2 )(Q 2 ); C(O)—Q 2; CO 2 —Q 2; C(O) N(R 2 )(Q 2 ); C(R′) 2 Q 2 . [0021] Each R is independently selected from hydrogen, —R 2 , —N(R 2 ) 2 , —OR 2 , SR 2 , —C(O)—N(R 2 ) 2 , —S (O 2 )—N(R 2 ) 2 , —C(O)—OR 2 or —C(O)R 2 wherein two adjacent R are optionally bound to one another and, together with each Y to which they are respectively bound, form a 4-8 membered carbocyclic or heterocyclic ring. [0022] R 2 is selected from hydrogen, (C 1 -C 3 )-alkyl, or (C 1 -C 3 )-alkenyl; each optionally substituted with —N(R′) 2 , —OR′, SR′, —C(O)—N(R′) 2 , —S(O 2 )—N(R′) 2 , —C(O)—OR′, —NSO 2 R 4 , —NSO 2 R 3 , —C(O)N(R′)(R 3 ), —NC(O)R 4 , —N(R′)(R 3 ), —N(R′)(R 4 ), —C(O)R 3 , —C(O)N(R′)(R 4 ), —N(R 4 ) 2 , —C(O)N═C(NH) 2 or R 3 . [0023] Y is N or C. [0024] Z is CH, N, C(OCH 3 ), C(CH 3 ), C(NH 2 ), C(OH) or C(F). [0025] U is selected from R or W. [0026] V is selected from —C(O)NH 2 , —P(O)(NH 2 ) 2 , or —SO 2 NH 2 . [0027] A, B, and C are independently selected from —O—, —CHR′-, —CHR 4 —, —NR′—, —NR 4 — or —S—. [0028] J is a (C 1 -C 4 ) straight chain or branched alkyl derivative substituted with 1-3 substituents selected from D, —T—C(O)R′, or —OPO 3 H 2 . [0029] D is selected from the group [0030] T is either O or NH. [0031] G is either NH 2 or OH. [0032] In another embodiment, the invention provides pharmaceutical compositions comprising the p38 inhibitors of this invention. These compositions may be utilized in methods for treating or preventing a variety of disorders, such as cancer, inflammatory diseases, autoimmune diseases, destructive bone disorders, proliferative disorders, infectious diseases, viral diseases and neurodegenerative diseases. These compositions are also useful in methods for preventing cell death and hyperplasia and therefore may be used to treat or prevent reperfusion/ischemia in stroke, heart attacks, and organ hypoxia. The compositions are also useful in methods for preventing thrombin-induced platelet aggregation. Each of these above-described methods is also part of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0033] These compounds have the general formula: [0034] wherein each of Q 1 and Q 2 are independently selected from a phenyl or 5-6 membered aromatic heterocyclic ring system, or a 8-10 membered bicyclic ring system comprising aromatic carbocyclic rings, aromatic heterocyclic rings or a combination of an aromatic carbocyclic ring and an aromatic heterocyclic ring. [0035] The rings that make up Q 1 are substituted with 1 to 4 substituents, each of which is independently selected from halo; C 1 -C 3 alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′ or CONR′ 2 ; O—(C 1 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′ or CONR′ 2 ; NR′ 2 ; OCF 3 ; CF 3 ; NO 2 ; CO 2 R′; CONR′; SR′; S(O 2 )N(R′) 2 ; SCF 3 ; CN; N(R′)C(O)R 4 ; N(R′)C(O)OR 4 ; N(R′)C(O)C(O)R 4 ; N(R′)S(O 2 )R 4 ; N(R′)R 4 ; N(R 4 ) 2 ; OR 4 ; OC(O)R 4 ; OP(O) 3 H 2 ; or N═C—N(R′) 2 . [0036] The rings that make up Q 2 are optionally substituted with up to 4 substituents, each of which is independently selected from halo; C 1 -C 3 straight or branched alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, S(O 2 )N(R′) 2 , N═C—N(R′) 2 , R 3 , or CONR′ 2 ; O—(C 1 -C 3 )-alkyl; O—(C 1 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, S(O 2 )N(R′) 2 , N═C—N(R′) 2 , R 3 , or CONR′ 2 ; NR′ 2 ; OCF 3 ; CF 3 ; NO 2 ; CO 2 R′; CONR′; R 3 ; OR 3 ; NR 3 ; SR 3 ; C(O)R 3 ; C(O)N(R′)R 3 ; C(O)OR 3 ; SR′; S(O 2 )N(R′) 2 ; SCF 3 ; N═C—N(R′) 2 ; or CN. [0037] Q 2 ′ is selected from phenyl or a 5-6 member aromatic heterocyclic ring optionally substituted with 1-3 substituents, each of which is independently selected from halogen; C 1 -C 3 alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, CONR′ 2 , or O—P(O 3 ) H 2 ; O—(C 2 -C 3 )-alkyl optionally substituted with NR′ 2 , OR′, CO 2 R′, CONR′ 2 , or OP (O 3 ) H 2 ; OCF 3 ; CF 3 ; OR 4 ; O—CO 2 R 4 ; O—P (O 3 ) H 2 ; CO 2 R′; CONR′ SR′; S(O 2 )N(R′) 2 ; SCF 3 ; CN; N(R′)C(o)R 4 ; N(R′)C(O)OR 4 ; N(R′)C(O)C(O)R 4 ; N(R′)S(O 2 )R 4 ; N(R′)R 4 ; N(R 4 ) 2 ; OR′; OC(O)R 4 ; OP(O) 3 H 2 ; or N═C—N(R′) 2 ; provided that Q 2 ′ is not phenyl optionally substituted 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl. [0038] R′ is selected from hydrogen; (C 1 -C 3 )-alkyl; (C 2 -C 3 )-alkenyl or alkynyl; phenyl or phenyl substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl; or a 5-6 membered heterocyclic ring system optionally substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl. [0039] R 3 is selected from 5-8 membered aromatic or non-aromatic carbocyclic or heterocyclic ring systems each optionally substituted with R′, R 4 , C(O)R′, —C(O)R 4 , —C(O)OR 4 or —J; or an 8-10 membered bicyclic ring system comprising aromatic carbocyclic rings, aromatic heterocyclic rings or a combination of an aromatic carbocyclic ring and an aromatic heterocyclic ring each optionally substituted with R′, R 4 , —C(O)R′, —C(O)R 4 , —C(O)OR 4 or —J. [0040] R 4 is (C 1 -C 4 )-straight or branched alkyl optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 ; or a 5-6 membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 . [0041] R is selected from hydrogen; (C 1 -C 3 )-alkyl optionally substituted with R 3 ; (C 2 -C 3 )-alkenyl or alkynyl each optionally substituted with R 3 ; phenyl or phenyl substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl; or a 5-6 membered heterocyclic ring system optionally substituted with 1 to 3 substituents independently selected from halo, methoxy, cyano, nitro, amino, hydroxy, methyl or ethyl. [0042] W is selected from N(R 2 ) SO 2 —N(R 2 ) 2 ; N(R 2 ) SO 2 —N(R 2 )(R 3 ); N(R 2 )C(O)—OR 2 ; N(R 2 )C(O)—N(R 2 ) 2 ; N(R 2 )C(O)—N(R 2 )(R 3 ); N(R 2 )C(O)—R 2 ; N(R 2 ) 2 ; C(O)—R 2 ; CH(OH)—R 2 ; C(O)—N(R 2 ) 2 ; C(O)—OR 2 ; J; or (C 1 -C 4 ) straight or branched alkyl optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , R 3 , SO 2 N(R 2 ) 2 , OC(O)R 2 , OC(O)R′, OC(O)N(R 2 ) 2 , —N(R 4 )(R 5 ), —C(O)N(R 5 )(R 2 ), —C(O)R 5 , —N(R 2 )C(O)N(R 2 )(R 5 ), —NC(O)OR 5 , —OC(O)N(R 2 )(R 5 ), or —J; a 5-6 membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 ; or a 8-10 membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 ; provided that W is not an R substituted C 1 alkyl. [0043] W′ is selected from N(R 2 )—SO 2 —Q 2 ; N(R 2 )—CO 2 —Q 2 ; N(R 2 )—C(O)—Q 2; N(R 2 )(Q 2 ); C(O)—Q 2; CO 2 —Q 2; C(O)N(R 2 )(Q 2 ); C(R 2 ) 2 Q 2 . [0044] Each R is independently selected from hydrogen, —R 2 , —N(R 2 ) 2 , —OR 2 , SR 2 , —C(O)—N(R 2 ) 2 , —S(O 2 )—N(R 2 ) 2 , —C(O)—OR 2 or —C(O)R 2 wherein two adjacent R are optionally bound to one another and, together with each Y to which they are respectively bound, form a 4-8 membered carbocyclic or heterocyclic ring. [0045] When the two R components form a ring together with the Y components to which they are respectively bound, it will obvious to those skilled in the art that a terminal hydrogen from each unfused R component will be lost. For example, if a ring structure is formed by binding those two R components together, one being —NH—CH 3 and the other being —CH 2 —CH 3 , one terminal hydrogen on each R component (indicated in bold) will be lost. Therefore, the resulting portion of the ring structure will have the formula —NH—CH 2 —CH 2 —CH 2 —. [0046] R 2 is selected from hydrogen, (C 1 -C 3 )-alkyl, or (C 1 -C 3 )-alkenyl; each optionally substituted with —N(R′) 2 , —OR′, SR′, —C(O)—N(R′) 2 , —S (O 2 )—N(R′) 2 , —C(O)—OR′, —NSO 2 R 4 , —NSO 2 R 3 , —C(O)N(R′)(R 3 ), —NC(O)R 4 , —N(R′)(R 3 ), —N(R′)(R 4 ), —C(O)R 3 , —C(O)N(R′)(R 4 ), —N(R 4 ) 2 , —C(O)N═C(NH) 2 or R 3 . [0047] Y is N or C. [0048] Z is CH, N, C(OCH 3 ), C(CH 3 ), C(NH 2 ), C(OH) or C(F) [0049] U is selected from R or W. [0050] V is selected from —C(O)NH 2 , —P(O)(NH 2 ) 2 , or —SO 2 NH 2 . [0051] A, B, and C are independently selected from —O—, —CHR′—, —CHR 4 —, —NR′—, —NR 4 — or —S—. [0052] J is a (C 1 -C 4 ) straight chain or branched alkyl derivative substituted with 1-3 substituents selected from D, —T—C(O)R′, or —OPO 3 H 2 . [0053] D is selected from the group [0054] T is either O or NH. [0055] G is either NH 2 or OH. [0056] According to a preferred embodiment, Q 1 is selected from phenyl or pyridyl containing 1 to 3 substituents, wherein at least one of said substituents is in the ortho position and said substituents are independently selected from chloro, fluoro, bromo, —CH 3 , —OCH 3 , —OH, —CF 3 , —OCF 3 , —O(CH 2 ) 2 CH 3 , NH 2 , 3,4-methylenedioxy, —N(CH 3 ) 2 , —NH—S(O) 2 -phenyl, —NH—C(O)O—CH 2 -4-pyridine, —NH—C(O)CH 2 -morpholine, —NH—C(O)CH 2 —N(CH 3 ) 2 , —NH—C(O)CH 2 -piperazine, —NH—C(O)CH 2 -pyrrolidine, —NH—C(O)C(O)-morpholine, —NH—C(O)C(O)-piperazine, —NH—C(O)C(O)-pyrrolidine, —O—C(O)CH 2 —N(CH 3 ) 2 , or —O—(CH 2 ) 2 —N(CH 3 ) 2 . [0057] Even more preferred are phenyl or pyridyl containing at least 2 of the above-indicated substituents both being in the ortho position. [0058] Some specific examples of preferred Q 1 are: [0059] Most preferably, Q 1 is selected from 2-fluoro-6-trifluoromethylphenyl, 2,6-difluorophenyl, 2,6-dichlorophenyl, 2-chloro-4-hydroxyphenyl, 2-chloro-4-aminophenyl, 2,6-dichloro-4-aminophenyl, 2,6-dichloro-3-aminophenyl, 2,6-dimethyl-4-hydroxyphenyl, 2-methoxy-3,5-dichloro-4-pyridyl, 2-chloro-4,5 methylenedioxy phenyl, or 2-chloro-4-(N-2-morpholino-acetamido)phenyl. [0060] According to a preferred embodiment, Q 2 is phenyl, pyridyl or naphthyl containing 0 to 3 substituents, wherein each substituent is independently selected from chloro, fluoro, bromo, methyl, ethyl, isopropyl, —OCH 3 , —OH, —NH 2 , —CF 3 , —OCF 3 , —SCH 3 , —OCH 3 , —C(O)OH, —C(O)OCH 3 , —CH 2 NH 2 , —N(CH 3 ) 2 , —CH 2 -pyrrolidine and —CH 2 O H. [0061] Some specific examples of preferred Q 2 are: [0062] unsubstituted 2-pyridyl or unsubstituted phenyl. [0063] Most preferred are compounds wherein Q 2 is selected from phenyl, 2-isopropylphenyl, 3,4-dimethylphenyl, 2-ethylphenyl, 3-fluorophenyl, 2-methylphenyl, 3-chloro-4-fluorophenyl, 3-chlorophenyl, 2-carbomethoxylphenyl, 2-carboxyphenyl, 2-methyl-4-chlorophenyl, 2-bromophenyl, 2-pyridyl, 2-methylenehydroxyphenyl, 4-fluorophenyl, 2-methyl-4-fluorophenyl, 2-chloro-4-fluorphenyl, 2,4-difluorophenyl, 2-hydroxy-4-fluorphenyl, 2-methylenehydroxy-4-fluorophenyl, 1-naphthyl, 3-chloro-2-methylenehydroxy, 3-chloro-2-methyl, or 4-fluoro-2-methyl. [0064] According to another preferred embodiment, each Y is C. [0065] According an even more preferred embodiment, each Y is C and the R and U attached to each Y component is selected from hydrogen or methyl. [0066] According to another preferred embodiment, W is a 0-4 atom chain terminating in an alcohol, amine, carboxylic acid, ester, amide, or heterocycle. [0067] Some specific examples of preferred W are: [0068] Most preferably, W is selected from: [0069] U has the same preferred and most preferred embodiments as W. [0070] According to an even more preferred embodiment, each Y is C, and W and/or U is not hydrogen. [0071] Some preferred embodiments are provided in Table 1 to 6 below: TABLE 1 Cmpd Number Structure VRT-042175 VRT-041238 VRT-042305 VRT-043675 VRT-042313 VRT-101257 VRT-101262 VRT-043176 VRT-043180 VRT-043181 VRT-101259 VRT-042196 [0072] [0072] TABLE 2 Cmpd Number Structure VRT-043188 VRT-100306 VRT-043190 VRT-043192 VRT-043672 VRT-043673 VRT-043674 VRT-100318 VRT-101256 VRT-101255 VRT-101253 VRT-101251 [0073] [0073] TABLE 3 Cmpd Number Structure VRT-100325 VRT-043683 VRT-101248 VRT-043685 VRT-043686 VRT-043690 VRT-100324 VRT-101249 VRT-043693 VRT-043694 VRT-043695 VRT-101247 [0074] [0074] TABLE 4 Cmpd Number Structure VRT-100310 VRT-043678 VRT-043191 VRT-100019 VRT-100020 VRT-043688 VRT-043675 VRT-042307 VRT-040569 VRT-100025 [0075] [0075] TABLE 5 Cmpd Number Structure VRT,100026 VRT-100304 VRT-100305 VRT-041291 VRT-032884 VRT-034465 VRT-100313 VRT-100315 VRT-100317 VRT-37742 VRT-100323 VRT-100146 [0076] [0076] TABLE 6 Cmpd Number Structure VRT-101094 VRT-043631 VRT-043008 VRT-042266 VRT-042169 VRT-043605 VRT-100075 VRT-100076 VRT-100077 [0077] Particularly preferred embodiments include: [0078] Particularly preferred embodiments also include: [0079] wherein X is NH 2 or N(CH 3 ) 2 ; [0080] wherein X is OH, NH 2 , or N(CH 3 ) 2 . [0081] Other particularly preferred embodiments include: [0082] Other particularly preferred embodiments include: [0083] Other particularly preferred embodiments [0084] Most preferred embodiments include: [0085] According to another embodiment, the present invention provides methods of producing the above-identified inhibitors of p38 of the formulae (Ia),(Ib), (Ic), (Id) and (Ie). Representative synthesis schemes for formula (Ia) are depicted below. [0086] Schemes 1-3 illustrate the preparation of compounds in which W is either an amino, carboxyl or an aldehyde function. In each case the particular moiety may be modified through chemistry well known in the literature. For example the final amino compounds D and N (schemes 1 and 4 respectively) may be acylated, sulfonylated or alkylated to prepare compounds within the scope of W. In all schemes, the L1 and L2 groups on the initial materials are meant to represent leaving groups ortho to the nitrogen atom in a heterocyclic ring. For example, compound A may be 2,6-dichloro-3 nitro pyridine. [0087] In Scheme 1, W is selected from amino-derivatized compounds such as N(R 2 ) SO 2 —N(R 2 ) 2 ; N(R 2 )SO 2 —N(R 2 )(R 3 ); N(R 2 )C(O)—N(R 2 ) 2 ; N N(R 2 )(R 3 ); N(R 2 )C(O)—R 2 ; or N(R 2 ) 2 . [0088] In Scheme 1, the Q2 ring is introduced utilizing one of many reactions know in the art which result in the production of biaryl compounds. One example may be the reaction of an aryl lithium compound with the pyridine intermediate A. Alternatively, an arylmetalic compound such as an aryl stannane or an aryl boronic acid may be reacted with the aryl halide portion (intermediate A) in the presence of a Pd° catalyst to form product B. In the next step, a Q1 substituted derivative such as a phenyl acetonitrile derivative may be treated with a base such as sodium hydride, sodium amide, LDA, lithium hexamethyldisilazide or any number of other non-nucleophilic bases to deprotonate the position alpha to the cyano group, which represents a masked amide moiety. This anion is then contacted with intermediate B to form C. The nitrile or equivalent group of intermediate C is then hydrolyzed to form the amide and the nitro group is subjected to reducing conditions to form the amine intermediate D. Intermediate D is then used to introduce various functionality defined by W through chemistry such as acylation, sulfonylation or alkylation reactions well known in the literature. Depending on the regiochemistry of the first two steps of this procedure, the first two steps may need to be reversed. [0089] In Scheme 2, W is selected from carboxyl-derivatized compounds such as C(O)—R 2 ; CH(OH)—R 2 ; C(O)—N(R 2 ) 2 ; or C(O)—OR 2 . [0090] Scheme 2 generally follows the procedures described for Scheme 1 except that a carboxyl intermediate such as E is the starting material. The first two steps mirror Scheme 1, and, as mentioned for Scheme 1, may be reversed depending on the regiochemistry of specific examples. Intermediate G is formed from these first two steps and this material may be hydrolyzed as mention to for the carboxyl intermediate H. The carboxyl group may then be modified according to well-known procedures from the literature to prepare analogs with defined W substituents such as acylations, amidations and esterifications. [0091] In Scheme 3, W is selected from (C 1 -C 4 ) straight or branched alkyl optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , R 3 , or SO 2 N(R 2 ) 2 ; or a 5-6membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 ; provided that W is not an R 3 substituted C 1 alkyl. [0092] In scheme 3 a pyridine derivative is metalated and quenched with one of many known electrophiles which can generate an aldehyde, to form intermediate I. The aldehyde can then be masked to form the dimethyl acetal J. This intermediate is then carried on as described in scheme 1 and 2 to introduce the Q1 and Q2 substituents, to produce intermediate L. As before, these two steps may be interchanged depending on specific regiochemistry. The masked aldehyde of L may then be deprotected and utilized to form compounds with the defined W substitution using well know chemistry such as alkylations and reductive aminations. [0093] Schemes 4-6 are similar to schemes 1-3 with the exception that the targeted compounds are those in which Z=Nitrogen. The steps for these schemes parallel 1-3 with the exception that the alkylation utilizing a phenyl acetonitrile is replaced with a reaction with a Q1 amine derivative such as a substituted aniline derivative. The amide portion of the molecule is then introduced in an acylation reaction with, for example, chlorosulfonyl isocyanate. [0094] In Scheme 4, W is selected from amino-derivatized groups such as N(R 2 )SO 2 —N(R 2 ) 2 ; N(R 2 )SO 2 —N(R 2 )(R 3 ); N(R 2 )C(O)—OR 2 ; N(R 2 )C(O)—N(R 2 ) 2 ; N(R 2 )C(O)—N(R 2 )(R 3 ); N(R 2 )C(O)—R 2 ; or N(R 2 ) 2 . [0095] In Scheme 4, intermediate B (from scheme 1) is treated with, for example, an aniline derivative in the presence of a base such as potassium carbonate. Additionally, a palladium catalyst may be utilized to enhance the reactivity of this general type of reaction, if needed. The resulting amine derivative is then acylated to form intermediate M. The nitro group of M is then reduced to form N and the amino group may then be derivatized as described for scheme 1. As mentioned for schemes 1-3, the steps involved in the introduction of the Q1 and Q2 substituents may be interchanged depending on the specific regiochemistry of specific compounds. [0096] In Scheme 5, W is selected from carboxyl-derivatized groups such as C(O)—R 2 ; CH(OH)—R 2 ; C(O)—N(R 2 ) 2 ; or C(O)—OR 2 . [0097] In Scheme 6, W is selected from (C 1 -C 4 ) straight or branched alkyl optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , R 3 , or SO 2 N(R 2 ) 2 ; or a 5-6 membered carbocyclic or heterocyclic ring system optionally substituted with N(R′) 2 , OR′, CO 2 R′, CON(R′) 2 , or SO 2 N(R 2 ) 2 ; provided that W is not an R 3 substituted C 1 alkyl. [0098] Schemes 5 and 6 generally follow the procedures mentioned above. [0099] One having skill in the art will recognize schemes 1-6 may be used to synthesize compounds having the general formula of (Ib), (Ic), (Id) and (Ie). [0100] According to another embodiment of the invention, the activity of the p38 inhibitors of this invention may be assayed in vitro, in vivo or in a cell line. In vitro assays include assays that determine inhibition of either the kinase activity or ATPase activity of activated p38. Alternate in vitro assays quantitate the ability of the inhibitor to bind to p38 and may be measured either by radiolabelling the inhibitor prior to binding, isolating the inhibitor/p38 complex and determining the amount of radiolabel bound, or by running a competition experiment where new inhibitors are incubated with p38 bound to known radioligands. [0101] Cell culture assays of the inhibitory effect of the compounds of this invention may determine the amounts of TNF, IL-1, IL-6 or IL-8 produced in whole blood or cell fractions thereof in cells treated with inhibitor as compared to cells treated with negative controls. Level of these cytokines may be determined through the use of commercially available ELISAs. [0102] An in vivo assay useful for determining the inhibitory activity of the p38 inhibitors of this invention are the suppression of hind paw edema in rats with Mycobacterium butyricum -induced adjuvant arthritis. This is described in J. C. Boehm et al., J. Med. Chem., 39, pp. 3929-37 (1996), the disclosure of which is herein incorporated by reference. The p38 inhibitors of this invention may also be assayed in animal models of arthritis, bone resorption, endotoxin shock and immune function, as described in A. M. Badger et al., J. Pharmacol. Experimental Therapeutics, 279, pp. 1453-61 (1996), the disclosure of which is herein incorporated by reference. [0103] The p38 inhibitors or pharmaceutical salts thereof may be formulated into pharmaceutical compositions for administration to animals or humans. These pharmaceutical compositions, which comprise an amount of p38 inhibitor effective to treat or prevent a p38-mediated condition and a pharmaceutically acceptable carrier, are another embodiment of the present invention. [0104] The term “p38-mediated condition”, as used herein means any disease or other deleterious condition in which p38 is known to play a role. This includes conditions known to be caused by IL-1, TNF, IL-6 or IL-8 overproduction. Such conditions include, without limitation, inflammatory diseases, autoimmune diseases, destructive bone disorders, proliferative disorders, infectious diseases, neurodegenerative diseases, allergies, reperfusion/ischemia in stroke, heart attacks, angiogenic disorders, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, thrombin-induced platelet aggregation, and conditions associated with prostaglandin endoperoxidase synthase-2. [0105] Inflammatory diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, acute pancreatitis, chronic pancreatitis, asthma, allergies, and adult respiratory distress syndrome. [0106] Autoimmune diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, glomerulonephritis, rheumatoid arthritis, systemic lupus erythematosus, scleroderma, chronic thyroiditis, Graves' disease, autoimmune gastritis, diabetes, autoimmune hemolytic anemia, autoimmune neutropenia, thrombocytopenia, atopic dermatitis, chronic active hepatitis, myasthenia gravis, multiple sclerosis, inflammatory bowel disease, ulcerative colitis, Crohn's disease, psoriasis, or graft vs. host disease. [0107] Destructive bone disorders which may be treated or prevented by the compounds of this invention include, but are not limited to, osteoporosis, osteoarthritis and multiple myeloma-related bone disorder. [0108] Proliferative diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, acute myelogenous leukemia, chronic myelogenous leukemia, metastatic melanoma, Kaposi's sarcoma, and multiple myeloma. [0109] Angiogenic disorders which may be treated or prevented by the compounds of this invention include solid tumors, ocular neovasculization, infantile haemangiomas. [0110] Infectious diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, sepsis, septic shock, and Shigellosis. [0111] Viral diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, acute hepatitis infection (including hepatitis A, hepatitis B and hepatitis C), HIV infection and CMV retinitis. [0112] Neurodegenerative diseases which may be treated or prevented by the compounds of this invention include, but are not limited to, Alzheimer's disease, Parkinson's disease, cerebral ischemias or neurodegenerative disease caused by traumatic injury. [0113] “p38-mediated conditions” also include ischemia/reperfusion in stroke, heart attacks, myocardial ischemia, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, and thrombin-induced platelet aggregation. [0114] In addition, p38 inhibitors of the instant invention are also capable of inhibiting the expression of inducible pro-inflammatory proteins such as prostaglandin endoperoxide synthase-2 (PGHS-2), also referred to as cyclooxygenase-2 (COX-2). Therefore, other “p38-mediated conditions” which may be treated by the compounds of this invention include edema, analgesia, fever and pain, such as neuromuscular pain, headache, cancer pain, dental pain and arthritis pain. [0115] The diseases that may be treated or prevented by the p38 inhibitors of this invention may also be conveniently grouped by the cytokine (IL-1, TNF, IL-6, IL-8) that is believed to be responsible for the disease. [0116] Thus, an IL-1-mediated disease or condition includes rheumatoid arthritis, osteoarthritis, stroke, endotoxemia and/or toxic shock syndrome, inflammatory reaction induced by endotoxin, inflammatory bowel disease, tuberculosis, atherosclerosis, muscle degeneration, cachexia, psoriatic arthritis, Reiter's syndrome, gout, traumatic arthritis, rubella arthritis, acute synovitis, diabetes, pancreatic β-cell disease and Alzheimer's disease. [0117] TNF-mediated disease or condition includes, rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis and other arthritic conditions, sepsis, septic shock, endotoxic shock, gram negative sepsis, toxic shock syndrome, adult respiratory distress syndrome, cerebral malaria, chronic pulmonary inflammatory disease, silicosis, pulmonary sarcoisosis, bone resorption diseases, reperfusion injury, graft vs. host reaction, allograft rejections, fever and myalgias due to infection, cachexia secondary to infection, AIDS, ARC or malignancy, keloid formation, scar tissue formation, Crohn's disease, ulcerative colitis or pyresis. TNF-mediated diseases also include viral infections, such as HIV, CMV, influenza and herpes; and veterinary viral infections, such as lentivirus infections, including, but not limited to equine infectious anemia virus, caprine arthritis virus, visna virus or maedi virus; or retrovirus infections, including feline immunodeficiency virus, bovine immunodeficiency virus, or canine immunodeficiency virus. [0118] IL-8 mediated disease or condition includes diseases characterized by massive neutrophil infiltration, such as psoriasis, inflammatory bowel disease, asthma, cardiac and renal reperfusion injury, adult respiratory distress syndrome, thrombosis and glomerulonephritis. [0119] In addition, the compounds of this invention may be used topically to treat or prevent conditions caused or exacerbated by IL-1 or TNF. Such conditions include inflamed joints, eczema, psoriasis, inflammatory skin conditions such as sunburn, inflammatory eye conditions such as conjunctivitis, pyresis, pain and other conditions associated with inflammation. [0120] In addition to the compounds of this invention, pharmaceutically acceptable salts of the compounds of this invention may also be employed in compositions to treat or prevent the above-identified disorders. [0121] Pharmaceutically acceptable salts of the compounds of this invention include those derived from pharmaceutically acceptable inorganic and organic acids and bases. Examples of suitable acid salts include acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptanoate, glycerophosphate, glycolate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oxalate, palmoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, salicylate, succinate, sulfate, tartrate, thiocyanate, tosylate and undecanoate. Other acids, such as oxalic, while not in themselves pharmaceutically acceptable, may be employed in the preparation of salts useful as intermediates in obtaining the compounds of the invention and their pharmaceutically acceptable acid addition salts. Salts derived from appropriate bases include alkali metal (e.g., sodium and potassium), alkaline earth metal (e.g., magnesium), ammonium and N—(C1-4 alkyl)4+ salts. This invention also envisions the quaternization of any basic nitrogen-containing groups of the compounds disclosed herein. Water or oil-soluble or dispersible products may be obtained by such quaternization. [0122] Pharmaceutically acceptable carriers that may be used in these pharmaceutical compositions include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat. [0123] The compositions of the present invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir. The term “parenteral” as used herein includes subcutaneous, intravenous, intramuscular, intra-articular, intra-synovial, intrasternal, intrathecal, intrahepatic, intralesional and intracranial injection or infusion techniques. Preferably, the compositions are administered orally, intraperitoneally or intravenously. [0124] Sterile injectable forms of the compositions of this invention may be aqueous or oleaginous suspension. These suspensions may be formulated according to techniques known in the art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono- or di-glycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions may also contain a long-chain alcohol diluent or dispersant, such as carboxymethyl cellulose or similar dispersing agents which are commonly used in the formulation of pharmaceutically acceptable dosage forms including emulsions and suspensions. Other commonly used surfactants, such as Tweens, Spans and other emulsifying agents or bioavailability enhancers which are commonly used in the manufacture of pharmaceutically acceptable solid, liquid, or other dosage forms may also be used for the purposes of formulation. [0125] The pharmaceutical compositions of this invention may be orally administered in any orally acceptable dosage form including, but not limited to, capsules, tablets, aqueous suspensions or solutions. In the case of tablets for oral use, carriers commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried cornstarch. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening, flavoring or coloring agents may also be added. [0126] Alternatively, the pharmaceutical compositions of this invention may be administered in the form of suppositories for rectal administration. These can be prepared by mixing the agent with a suitable non-irritating excipient which is solid at room temperature but liquid at rectal temperature and therefore will melt in the rectum to release the drug. Such materials include cocoa butter, beeswax and polyethylene glycols. [0127] The pharmaceutical compositions of this invention may also be administered topically, especially when the target of treatment includes areas or organs readily accessible by topical application, including diseases of the eye, the skin, or the lower intestinal tract. Suitable topical formulations are readily prepared for each of these areas or organs. [0128] Topical application for the lower intestinal tract can be effected in a rectal suppository formulation (see above) or in a suitable enema formulation. Topically-transdermal patches may also be used. [0129] For topical applications, the pharmaceutical compositions may be formulated in a suitable ointment containing the active component suspended or dissolved in one or more carriers. Carriers for topical administration of the compounds of this invention include, but are not limited to, mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene, polyoxypropylene compound, emulsifying wax and water. Alternatively, the pharmaceutical compositions can be formulated in a suitable lotion or cream containing the active components suspended or dissolved in one or more pharmaceutically acceptable carriers. Suitable carriers include, but are not limited to, mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. [0130] For ophthalmic use, the pharmaceutical compositions may be formulated as micronized suspensions in isotonic, pH adjusted sterile saline, or, preferably, as solutions in isotonic, pH adjusted sterile saline, either with or without a preservative such as benzylalkonium chloride. Alternatively, for ophthalmic uses, the pharmaceutical compositions may be formulated in an ointment such as petrolatum. [0131] The pharmaceutical compositions of this invention may also be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and may be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other conventional solubilizing or dispersing agents. [0132] The amount of p38 inhibitor that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated, the particular mode of administration. Preferably, the compositions should be formulated so that a dosage of between 0.01-100 mg/kg body weight/day of the inhibitor can be administered to a patient receiving these compositions. [0133] It should also be understood that a specific dosage and treatment regimen for any particular patient will depend upon a variety of factors, including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, rate of excretion, drug combination, and the judgment of the treating physician and the severity of the particular disease being treated. The amount of inhibitor will also depend upon the particular compound in the composition. [0134] According to another embodiment, the invention provides methods for treating or preventing a p38-mediated condition comprising the step of administering to a patient one of the above-described pharmaceutical compositions. The term “patient”, as used herein, means an animal, preferably a human. [0135] Preferably, that method is used to treat or prevent a condition selected from inflammatory diseases, autoimmune diseases, destructive bone disorders, proliferative disorders, infectious diseases, degenerative diseases, allergies, reperfusion/ischemia in stroke, heart attacks, angiogenic disorders, organ hypoxia, vascular hyperplasia, cardiac hypertrophy, and thrombin-induced platelet aggregation. [0136] According to another embodiment, the inhibitors of this invention are used to treat or prevent an IL-1, IL-6, IL-8 or TNF-mediated disease or condition. Such conditions are described above. [0137] Depending upon the particular p38-mediated condition to be treated or prevented, additional drugs, which are normally administered to treat or prevent that condition, may be administered together with the inhibitors of this invention. For example, chemotherapeutic agents or other anti-proliferative agents may be combined with the p38 inhibitors of this invention to treat proliferative diseases. [0138] Those additional agents may be administered separately, as part of a multiple dosage regimen, from the p38 inhibitor-containing composition. Alternatively, those agents may be part of a single dosage form, mixed together with the p38 inhibitor in a single composition. [0139] In order that the invention described herein may be more fully understood, the following examples are set forth. It should be understood that these examples are for illustrative purposes only and are not to be construed as limiting this invention in any manner. EXAMPLE 1 Synthesis of p38 Inhibitor Compound 6 [0140] [0140] [0141] To a solution of LDA (60 mmol, 40 mLs) at −78° C., was added dropwise a solution of 2,6-Dibromopyridine (40 mmol, 9.48 gms) in THF (30 mLs, dried). The mixture was stirred at −78° C. for 20 minutes. Ethyl formate (400 mmol, 32.3 mLs) was added and stirring was continued at −78° C. for 2 hours. Saturated ammonium chloride (200 mLs) was added and the mixture was warmed to room temperature. The reaction mixture was diluted with ethyl acetate and the organic layer was washed with aqueous acid and base. The organic layer was dried and evaporated in vacuo. The resulting material was purified by flash chromatography on silica gel followed by eluting with 10% ethyl acetate in n-hexane to afford 1 (32 mmol, 8.41 gms) as a white solid. [0142] A solution of 1 (13.08 mmol, 3.1 gms) and concentrated sulfuric acid (1 mL) in methanol (50 mL) was refluxed overnight. The reaction mixture was cooled, neutralized with aqueous base and extracted into ethyl acetate. Drying and evaporation of the organic layer afforded 2 (11.77 mmol, 3.63 gms) as an oil. [0143] To a solution of t-Butoxide (2.2 mmol, 2 mLs) was added dropwise a solution of 2,6-Dichloroaniline (1.0 mmol, 162 mgs) in THF (2 mL, dried). The mixture was stirred at room temperature for 20 minutes. A solution of 2 (1.0 mmol, 309 mgs) in THF (5 mLs) was added and stirring was continued for 3 hours. The reaction mixture was diluted with ethyl acetate and the organic layer was washed with aqueous acid and base. The organic layer was dried and evaporated in vacuo. The resulting material was purified by flash chromatography on silica gel followed by eluting with 5% acetone in n-hexane to afford 3 (0.33 mmol, 128 mgs) as an orange solid. [0144] o-Tolylboronic acid (0.34 mmol, 46 mgs), and 3 (0.20 mmol, 80 mgs) were dissolved in a toluene/ethanol (5/1) mixture. Thallium carbonate (0.5, 235 mgs) and tetrakis(triphenylphosphine)palladium (0) (10 mgs) was added to the solution and the slurry was allowed to reflux for 30 minutes. The reaction mixture was diluted with ethyl acetate and the organic layer was washed with aqueous acid and base. The organic layer was dried and evaporated in vacuo. The resulting material was purified by flash chromatography on silica gel followed by eluting with 5% methanol in methylene chloride to afford 4 (0.17 mmol, 61 mgs) as a white solid. [0145] A solution of 4 (0.17 mmol, 61 mgs) and chlorosulfonyl isocyanate (1 mmol, 141.5 mgs) in methylene chloride (5 mLs) was stirred at room temperature overnight. The reaction mixture was diluted with ethyl acetate and the organic layer was washed with aqueous acid and base. The organic layer was dried and evaporated in vacuo. The resulting material was purified by flash chromatography on silica gel followed by eluting with 5% acetone in n-hexane to afford 5 (0.12 mmol, 46 mgs) as a white solid. [0146] Sodium borohydride (1.0 mmol, 39.8 mgs) was added to a solution of 5 (0.12 mmol, 46 mgs) in methanol (10 mLs) and the solution was stirred for 15 minutes. The reaction was quenched with water. The reaction mixture was then diluted with ethyl acetate and the organic layer was washed with aqueous acid and base. The organic layer was dried and evaporated in vacuo. The resulting material was purified by flash chromatography to afford 6 (0.08 mmol, 36 mgs) as a white solid. [0147] The spectral data for compound 6 was: [0148] [0148] 1 HNMR (500 MHz, CDCl 3 ) δ 7.90 (d, 1H), 7.60 (d, 2H), 7.5-7.3 (m, 5H), 6.30 (d, 2H), 4.5 (s, 2H), 2.3 (s, 2H). Synthesis of p38 Inhibitor Compound 7 [0149] [0149] [0150] The amino-alcohol (500 mg, 1.43 mmol), which was prepared in the same manner as 4, was dissolved in dichloromethane. Triethylamine (433 mg, 4.29 mmol) was added, followed by acetyl chloride (168 mg, 2.15 mmol). The mixture was stirred at room temperature for one hour, poured into water, and extracted with dichloromethane. The organic extract was evaporated in vacuo and the residue was dissolved in 10.0 mL of toluene. A 20% solution of phosgene in toluene (5.0 mL) was added and the solution was refluxed for two hours. The solution was cooled and 5.0 mL of concentrated ammonium hydroxide was added, precipitating a white solid. The mixture was poured into water and extracted with toluene. The organic extract was dried (MgSO 4 ) and evaporated in vacuo to afford 205 mg of the urea-acetate 7 as a white solid. [0151] The spectral data for compound 7 was: [0152] [0152] 1 H NMR (500 MHz, CDCl 3 ) δ 7.80 (d, 1H), 7.62-7.50 (m, 2H), 7.25-7.0 (m, 5H), 6.59 (d, 1H), 5.1 (s, 2H), 2.12 (s, 3H). HRMS showed MH+434.2 as the major peak. Synthesis of p38 Inhibitor Compound 8 [0153] [0153] [0154] The urea-alcohol (548 mg, 1.4 mmol), which was prepared in the same manner as 6, was dissolved in 5.0 mL of toluene. A 20% solution of phosgene in toluene (5.0 mL) was added and the solution was refluxed for two hours. The solution was cooled and 5.0 mL of concentrated ammonium hydroxide was added, precipitating a white solid. The mixture was poured into water and extracted with toluene. The organic extract was dried (MgSO 4 ) and evaporated in vacuo to afford 284 mg of the carbamate 8 as a white solid. [0155] The spectral data of compound 8 was: [0156] [0156] 1 H NMR (500 MHz, CDCl 3 ) δ 7.77 (d, 1H), 7.55-7.45 (m, 2H), 7.15-6.95 (m, 5H), 6.50 (d, 1H), 5.40 (br s, 2H), 5.00 (s, 2H). HRMS showed MH+ 435.1 as the major peak. EXAMPLE 2 Synthesis of p38 Inhibitor Compound 16 [0157] [0157] [0158] One equivalent of 2,6-dichloropyridine-4-carboxylic acid was dissolved in THF. The solution was cooled to 0° C. and one equivalent of borane dimethyl sulfide complex was added. The solution was stirred at room temperature for twelve hours. The mixture was poured into water and extracted with diethyl ether. The ether extract was dried, and evaporated in vacuo to afford 9 in 93% yield. [0159] One equivalent of 9 was dissolved in methylene chloride. One equivalent of methyl chloromethyl ether was added, followed by the addition of one equivalent of ethyl diisopropylamine. The reaction was stirred at room temperature for several hours, poured into water and extracted with a water-immiscible solvent. The extract was dried and evaporated in vacuo to afford 10 in 86% yield. [0160] One equivalent of potassium t-butoxide was added to a solution of one equivalent of 2,6-dichlorophenyl acetonitrile in THF at room temperature. The mixture was stirred at room temperature for thirty minutes, and a solution of the dichloropyridine 10 in THF was added. After stirring for 1.5 hours, the mixture was poured into aqueous ammonium chloride and extracted with ethyl acetate. The extract was dried and evaporated in vacuo. The residue was purified by flash chromatography to afford 11 in 79% yield as a white powder. [0161] The acetal 11 was mixed with concentrated hydrochloric acid and stirred for several hours. The mixture was extracted with a water-immicible organic solvent. The extract was washed with saturated aqueous NaHCO 3 , dried, and evaporated in vacuo to afford 12. [0162] The nitrile 12 was mixed with concentrated sulfuric acid and heated to 100° C. for several minutes. The mixture was cooled, poured onto ice, and filtered to afford 13. [0163] One equivalent of the chloropyridine 13 was dissolved in 1,2-dimethoxyethane. One equivalent of 3-chloro-2-methylphenylboronic acid was added. A solution of one equivalent of sodium carbonate in water was added along with a catalytic amount of tetrakis (triphenylphosphine) palladium (0). The mixture was heated to 80° C. for several hours. The mixture was poured into water and extracted with a water-immiscible organic solvent. The extract was dried, evaporated in vacuo and purified by flash chromatography to afford 14. [0164] One equivalent of the alcohol 14 was dissolved in THF. The solution was cooled to 0° C. and one equivalent of methanesulfonyl chloride was added following by one equivalent of triethylamine. The solution was stirred for several hours, poured into water, and extracted with a water-immiscible solvent. The extract was dried and evaporated in vacuo to afford the crude mesylate 15. [0165] One equivalent of the methanesulfonyl ester 15 was dissolved in THF. The solution was cooled to 0° C. and one equivalent of N-ethyl piperazine was added following by one equivalent of triethylamine. The solution was stirred for several hours, poured into water, and extracted with a water-immiscible solvent. The extract was dried, evaporated, and purified by flash chromatography to afford the pure amine 16. [0166] The spectral data for compound 16 is: [0167] [0167] 1 H NMR (500 MHz, CDCl 3 ) δ 9.85 (br s, 1H), 7.47 (dd, 1H), 7.42 (d, 1H), 7.27 (m, 5H), 6.75 (s, 1H), 5.95 (s, 1H), 5.7 (br s, 1H), 3.5 (ABq, 2H), 2.5-2.3 (m, 1OH), 2.3 (s, 3H), 1.2 (t, 3H). EXAMPLE 2 Cloning of p38 Kinase in Insect Cells [0168] Two splice variants of human p38 kinase, CSBP1 and CSBP2, have been identified. Specific oligonucleotide primers were used to amplify the coding region of CSBP2 cDNA using a HeLa cell library (Stratagene) as a template. The polymerase chain reaction product was cloned into the pET-15b vector (Novagen). The baculovirus transfer vector, pVL-(His)6-p38 was constructed by subcloning a XbaI-BamHI fragment of pET15b-(His)6-p38 into the complementary sites in plasmid pVL1392 (Pharmingen). [0169] The plasmid pVL-(His)6-p38 directed the synthesis of a recombinant protein consisting of a 23-residue peptide (MGSSHHHHHHSSGLVPRGSHMLE, where LVPRGS represents a thrombin cleavage site) fused in frame to the N-terminus of p38, as confirmed by DNA sequencing and by N-terminal sequencing of the expressed protein. Monolayer culture of Spodoptera frugiperda (Sf9) insect cells (ATCC) was maintained in TNM-FH medium (Gibco BRL) supplemented with 10% fetal bovine serum in a T-flask at 27° C. Sf9 cells in log phase were co-transfected with linear viral DNA of Autographa califonica nuclear polyhedrosis virus (Pharmingen) and transfer vector pVL-(His)6-p38 using Lipofectin (Invitrogen). The individual recombinant baculovirus clones were purified by plaque assay using 1% low melting agarose. EXAMPLE 3 Expression and Purification of Recombinant p38 Kinase [0170] [0170] Trichoplusia ni (Tn-368) High-Five™ cells (Invitrogen) were grown in suspension in Excel-405 protein free medium (JRH Bioscience) in a shaker flask at 27° C. Cells at a density of 1.5×10 6 cells/ml were infected with the recombinant baculovirus described above at a multiplicity of infection of 5. The expression level of recombinant p38 was monitored by immunoblotting using a rabbit anti-p38 antibody (Santa Cruz Biotechnology). The cell mass was harvested 72 hours after infection when the expression level of p38 reached its maximum. [0171] Frozen cell paste from cells expressing the (His) 6 -tagged p38 was thawed in 5 volumes of Buffer A (50 mM NaH 2 PO 4 pH 8.0, 200 mM NaCl, 2 mM β-Mercaptoethanol, 10% Glycerol and 0.2 mM PMSF). After mechanical disruption of the cells in a microfluidizer, the lysate was centrifuged at 30,000×g for 30 minutes. The supernatant was incubated batchwise for 3-5 hours at 4° C. with Talon™ (Clontech) metal affinity resin at a ratio of 1 ml of resin per 2-4 mgs of expected p38. The resin was settled by centrifugation at 500×g for 5 minutes and gently washed batchwise with Buffer A. The resin was slurried and poured into a column (approx. 2.6×5.0 cm) and washed with Buffer A +5 mM imidazole. [0172] The (His) 6 -p38 was eluted with Buffer A+100 mM imidazole and subsequently dialyzed overnight at 4° C. against 2 liters of Buffer B, (50 mM HEPES, pH 7.5, 25 mM β-glycerophosphate, 5% glycerol, 2 mM DTT). The His 6 tag was removed by addition of at 1.5 units thrombin (Calbiochem) per mg of p38 and incubation at 20° C. for 2-3 hours. The thrombin was quenched by addition of 0.2 mM PMSF and then the entire sample was loaded onto a 2 ml benzamidine agarose (American International Chemical) column. [0173] The flow through fraction was directly loaded onto a 2.6×5.0 cm Q-Sepharose (Pharmacia) column previously equilibrated in Buffer B+0.2 mM PMSF. The p38 was eluted with a 20 column volume linear gradient to 0.6M NaCl in Buffer B. The eluted protein peak was pooled and dialyzed overnight at 4 C vs. Buffer C (50 mM HEPES pH 7.5, 5% glycerol, 50 mM NaCl, 2 mM DTT, 0.2 mM PMSF). [0174] The dialyzed protein was concentrated in a Centriprep (Amicon) to 3-4 ml and applied to a 2.6×100 cm Sephacryl S-100HR (Pharmacia) column. The protein was eluted at a flow rate of 35 ml/hr. The main peak was pooled, adjusted to 20 mM DTT, concentrated to 10-80 mgs/ml and frozen in aliquots at −70° C. or used immediately. EXAMPLE 4 Activation of p38 [0175] p38 was activated by combining 0.5 mg/ml p38 with 0.005 mg/ml DD-double mutant MKK6 in Buffer B+10 mM MgCl 2 , 2 mM ATP, 0.2 mM Na 2 VO 4 for 30 minutes at 20° C. The activation mixture was then loaded onto a 1.0×10 cm MonoQ column (Pharmacia) and eluted with a linear 20 column volume gradient to 1.0 M NaCl in Buffer B. The activated p38 eluted after the ADP and ATP. The activated p38 peak was pooled and dialyzed against buffer B+0.2 mM Na 2 VO 4 to remove the NaCl. The dialyzed protein was adjusted to 1.1 M potassium phosphate by addition of a 4.0 M stock solution and loaded onto a 1.0×10 cm HIC (Rainin Hydropore) column previously equilibrated in Buffer D (10% glycerol, 20 mM β-glycerophosphate, 2.0 mM DTT)+1.1 MK 2 HPO 4 . The protein was eluted with a 20 column volume linear gradient to Buffer D+50 mM K 2 HPO 4 . The double phosphorylated p38 eluted as the main peak and was pooled for dialysis against Buffer B+0.2 mM Na 2 VO 4 . The activated p38 was stored at −70° C. EXAMPLE 5 p38 Inhibition Assays [0176] A. Inhibition of Phosphorylation of EGF Receptor Peptide [0177] This assay was carried out in the presence of 10 mM MgCl 2 , 25 mM β-glycerophosphate, 10% glycerol and 100 mM HEPES buffer at pH 7.6. For a typical IC 50 determination, a stock solution was prepared containing all of the above components and activated p38 (5 nM). The stock solution was aliquotted into vials. A fixed volume of DMSO or inhibitor in DMSO (final concentration of DMSO in reaction was 5%) was introduced to each vial, mixed and incubated for 15 minutes at room temperature. EGF receptor peptide, KRELVEPLTPSGEAPNQALLR, a phosphoryl acceptor in p38-catalyzed kinase reaction (1), was added to each vial to a final concentration of 200 μM. The kinase reaction was initiated with ATP (100 μM) and the vials were incubated at 30° C. After 30 minutes, the reactions were quenched with equal volume of 10% trifluoroacetic acid (TFA). [0178] The phosphorylated peptide was quantified by HPLC analysis. Separation of phosphorylated peptide from the unphosphorylated peptide was achieved on a reverse phase column (Deltapak, 5 μm, C18 100D, Part no. 011795) with a binary gradient of water and acteonitrile, each containing 0.1% TFA. IC 50 (concentration of inhibitor yielding 50% inhibition) was determined by plotting the percent (%) activity remaining against inhibitor concentration. [0179] B. Inhibition of ATPase Activity [0180] This assay is carried out in the presence of 10 mM MgCl 2 , 25 mM β-glycerophosphate, 10% glycerol and 100 mM HEPES buffer at pH 7.6. For a typical Ki determination, the Km for ATP in the ATPase activity of activated p38 reaction is determined in the absence of inhibitor and in the presence of two concentrations of inhibitor. A stock solution is prepared containing all of the above components and activated p38 (60 nM). The stock solution is aliquotted into vials. A fixed volume of DMSO or inhibitor in DMSO (final concentration of DMSO in reaction was 2.5%) is introduced to each vial, mixed and incubated for 15 minutes at room temperature. The reaction is initiated by adding various concentrations of ATP and then incubated at 30° C. After 30 minutes, the reactions are quenched with 50 μl of EDTA (0.1 M, final concentration), pH 8.0. The product of p38 ATPase activity, ADP, is quantified by HPLC analysis. [0181] Separation of ADP from ATP is achieved on a reversed phase column (Supelcosil, LC-18, 3 μm, part no. 5-8985) using a binary solvent gradient of following composition: Solvent A—0.1 M phosphate buffer containing 8 mM tetrabutylammonium hydrogen sulfate (Sigma Chemical Co., catalogue no. T-7158), Solvent B—Solvent A with 30% methanol. [0182] Ki is determined from the rate data as a function of inhibitor and ATP concentrations. [0183] p38 inhibitors of this invention will inhibit the ATPase activity of p38. [0184] C. Inhibition of IL-1, TNF, IL-6 and IL-8 Production in LPS—Stimulated PBMCs [0185] Inhibitors were serially diluted in DMSO from a 20 mM stock. At least 6 serial dilutions were prepared. Then 4× inhibitor stocks were prepared by adding 4 μl of an inhibitor dilution to 1 ml of RPMI1640 medium/10% fetal bovine serum. The 4× inhibitor stocks contained inhibitor at concentrations of 80 μM, 32 μM, 12.8 μM, 5.12 μM, 2.048 μM, 0.819 μM, 0.328 μM, 0.131 μM, 0.052 μM, 0.021 μM etc. The 4× inhibitor stocks were pre-warmed at 37° C. until use. [0186] Fresh human blood buffy cells were separated from other cells in a Vacutainer CPT from Becton & Dickinson (containing 4 ml blood and enough DPBS without Mg 2+ /Ca 2+ to fill the tube) by centrifugation at 1500×g for 15 min. Peripheral blood mononuclear cells (PBMCs), located on top of the gradient in the Vacutainer, were removed and washed twice with RPMI1640 medium/10% fetal bovine serum. PBMCs were collected by centrifugation at 500×g for 10 min. The total cell number was determined using a Neubauer Cell Chamber and the cells were adjusted to a concentration of 4.8×10 cells/ml in cell culture medium (RPMI1640 supplemented with 10% fetal bovine serum). [0187] Alternatively, whole blood containing an anti-coagulant was used directly in the assay. [0188] 100 μl of cell suspension or whole blood were placed in each well of a 96-well cell culture plate. Then 50 μl of the 4× inhibitor stock was added to the cells. Finally, 50 μl of a lipopolysaccharide (LPS) working stock solution (16 ng/ml in cell culture medium) was added to give a final concentration of 4 ng/ml LPS in the assay. The total assay volume of the vehicle control was also adjusted to 200 μl by adding 50 μpl cell culture medium. The PBMC cells or whole blood were then incubated overnight (for 12-15 hours) at 37° C./5% CO 2 in a humidified atmosphere. [0189] The next day the cells were mixed on a shaker for 3-5 minutes before centrifugation at 500×g for 5 minutes. Cell culture supernatants were harvested and analyzed by ELISA for levels of IL-1b (R & D Systems, Quantikine kits, #DBL50), TNF-α (BioSource, #KHC3012), IL-6 (Endogen, #EH2-IL6) and IL-8 (Endogen, #EH2-IL8) according to the instructions of the manufacturer. The ELISA data were used to generate dose-response curves from which IC50 values were derived. [0190] Results for the kinase assay (“kinase”; subsection A, above), IL-1 and TNF in LPS-stimulated PBMCs (“cell”) and IL-1, TNF and IL-6 in whole blood (“WB”) for various p38 inhibitors of this invention are shown in Table 7 below: TABLE 7 Kinase Cell IL-1 Cell TNF WB IL-1 WB TNF WB IL-6 Compound M.W. IC50 (uM) IC50 (uM) IC50 (uM) IC50 (uM) IC50 (uM) IC50 (uM) 17 402.28 0.056 0.021 0.14 0.42 0.064 0.25 18 436.32 0.002 0.02 0.05 0.118 0.055 0.18 19 387.36 0.027 0.027 0.01 0.057 0.09 0.075 [0191] Other p38 inhibitors of this invention will also inhibit phosphorylation of EGF receptor peptide, and will inhibit the production of IL-1, TNF and IL-6, as well as IL-8, in LPS-stimulated PBMCs or in whole blood. [0192] D. Inhibition of IL-6 and IL-8 Production in IL-1-Stimulated PBMCs [0193] This assay is carried out on PBMCs exactly the same as above except that 50 μl of an IL-1b working stock solution (2 ng/ml in cell culture medium) is added to the assay instead of the (LPS) working stock solution. [0194] Cell culture supernatants are harvested as described above and analyzed by ELISA for levels of IL-6 (Endogen, #EH2-IL6) and IL-8 (Endogen, #EH2-IL8) according to the instructions of the manufacturer. The ELISA data are used to generate dose-response curves from which IC50 values were derived. [0195] E. Inhibition of LPS-induced Prostaglandin Endoperoxide Synthase-2 (PGHS-2, or COX-2) Induction in PBMCs [0196] Human peripheral mononuclear cells (PBMCs) are isolated from fresh human blood buffy coats by centrifugation in a Vacutainer CPT (Becton & Dickinson). 15×10 6 cells are seeded in a 6-well tissue culture dish containing RPMI 1640 supplemented with 10% fetal bovine serum, 50 U/ml penicillin, 50 μg/ml streptomycin, and 2 mM L-glutamine. Compounds are added at 0.2, 2.0 and 20 μM final concentrations in DMSO. LPS is then added at a final concentration of 4 ng/ml to induce enzyme expression. The final culture volume is 10 ml/well. [0197] After overnight incubation at 37° C., 5% CO 2 , the cells are harvested by scraping and subsequent centrifugation, the supernatant is removed, and the cells are washed twice in ice-cold DPBS (Dulbecco's phosphate buffered saline, BioWhittaker). The cells are lysed on ice for 10 min in 50 μl cold lysis buffer (20 mM Tris-HCl, pH 7.2, 150 mM NaCl, 1% Triton-X-100, 1% deoxycholic acid, 0.1% SDS, 1 mM EDTA, 2% aprotinin (Sigma), 10 μg/ml pepstatin, 10 μg/ml leupeptin, 2 mM PMSF, 1 mM benzamidine, 1 mM DTT) containing 1 μl Benzonase (DNAse from Merck). The protein concentration of each sample is determined using the BCA assay (Pierce) and bovine serum albumin as a standard. Then the protein concentration of each sample is adjusted to 1 mg/ml with cold lysis buffer. To 100 μl lysate an equal volume of 2×SDS PAGE loading buffer is added and the sample is boiled for 5 min. Proteins (30 μg/lane) are size-fractionated on 4-20% SDS PAGE gradient gels (Novex) and subsequently transferred onto nitrocellulose membrane by electrophoretic means for 2 hours at 100 mA in Towbin transfer buffer (25 mM Tris, 192 mM glycine) containing 20% methanol. After transfer, the membrane is pretreated for 1 hour at room temperature with blocking buffer (5% non-fat dry milk in DPBS supplemented with 0.1% Tween-20) and washed 3 times in DPBS/0.1% Tween-20. The membrane is incubated overnight at 4° C. with a 1: 250 dilution of monoclonal anti-COX-2 antibody (Transduction Laboratories) in blocking buffer. After 3 washes in DPBS/0.1% Tween-20, the membrane is incubated with a 1:1000 dilution of horseradish peroxidase-conjugated sheep antiserum to mouse Ig (Amersham) in blocking buffer for 1 h at room temperature. Then the membrane is washed again 3 times in DPBS/0.1% Tween-20. An ECL detection system (SuperSignal™ CL-HRP Substrate System, Pierce) is used to determine the levels of expression of COX-2. [0198] While we have hereinbefore presented a number of embodiments of this invention, it is apparent that our basic construction can be altered to provide other embodiments which utilize the methods of this invention.

The present invention relates to inhibitors of p38, a mammalian protein kinase involved cell proliferation, cell death and response to extracellular stimuli. The invention also relates to methods for producing these inhibitors. The invention also provides pharmaceutical compositions comprising the inhibitors of the invention and methods of utilizing those compositions in the treatment and prevention of various disorders.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to apparatus for burning crude oil and has particular application to an apparatus for burning crude oil derived from off-shore oil well installations. 2. Description of the Prior Art When oil-well production tests are undertaken at sea, it is necessary to dispose of the crude oil collected during such tests, and which oil is frequently contaminated with water, sand, mud and various kinds of waste from the bottom of the well. Given that production trials generally last from a few hours to a few days, the volume of oil collected, being at most several thousand cubic meters, cannot be dumped into the sea because of the pollution problems caused thereby and does not justify special transport for its evacuation. Further, given that the collecting system for an off-shore oil-well is only installed once the viability of the well has been established, the only economically viable solution is to dispose of the first samples of crude oil collected by on-site combustion. As stated above this crude oil with its contaminants is a product rich in heavy particles and is far from being easy to burn. Combustion of the oil involves the use of substantial burner means which can handle the combustion of up to 2000 m 3 of oil per day and such combustion must be undertaken in conditions of absolute security for both the drilling installation and the drilling team. A serious disadvantage with conventional burners is that whilst such burners can initially be installed to direct the burner flames and the products of combustion in a safe direction there is always a danger that the wind will adversely affect the flame direction to the detriment of the surrounding environment. SUMMARY OF THE INVENTION The present invention seeks to provide apparatus for burning crude oil, capable of being mounted at a safe location and adjustable at such location to afford additional security to the surrounding environment. Statement of Invention According to the present invention there is provided apparatus for burning crude oil comprising a burner assembly including a plurality of substantially horizontal burners arranged in pairs, means for supplying oil for combustion and compressed air to the burners, and flame control water nozzles, characterised in that the burner assembly is arranged for pivotal displacement about a substantially vertical axis. Preferably the burner assembly is pivotally attached to a stand which limits the angular displacement of the assembly about the vertical axis. Preferably the pivotal displacement of said burner assembly about the vertical axis of limited to 45° to each side of a mid-position for the assembly. Preferably the burner assembly includes pilot burners for igniting the crude oil burners. In preferred embodiments of the invention the burner assembly includes valves for controlling the supply of oil to the crude oil burners and/or valves for controlling the supply of compressed air to the crude oil burners and/or valves for controlling the supply of water to the water nozzles. Preferably each pair of crude oil burners is provided with individual valve controls so that each pair of such burners can be operated independently of other pairs of such burners and conveniently each pair of such burners is supplied with oil and compressed air via common valves, whereby the burners of each pair are arranged to operate simultaneously. In a preferred embodiment the crude oil or the compressed air or the water is delivered to the burner assembly via a fluid chamber and the vertical pivotal axis of the assembly passes through such chamber. More preferably, more than one fluid is delivered to the burner assembly via fluid chambers, there being a fluid chamber individual to each fluid, and the vertical pivotal axis passes through each fluid chamber. The, or each, fluid chamber is conveniently formed by upper and lower coupling parts, one of said coupling parts has a fixed position relative to the stand whilst the other said coupling part has a fixed position relative to the burner assembly. The coupling part fixed relative to the stand includes a fluid inlet from a supply source to the chamber and that coupling part fixed relative to the assembly includes a fluid outlet from the chamber to the burner assembly. Preferably ducts supplying fluids to the assembly pass through said stand with the duct axes in the same vertical plane. Preferably the burner assembly is contained within a cage and the cage is fixed relative to the burner assembly. The cage may conveniently comprise tubular members defining upper and lower rectangular frames, connected by front and rear upright members and by inclined members, and the rectangular frames are preferably strengthened by diagonal members. In a preferred example in accordance with the invention apparatus for burning crude oil comprises a burner assembly within a rectangular box-like cage of tubular material fixed relative to the burner assembly, the burner assembly including a plurality of burners arranged with their axes substantially horizontal, the burners being arranged in pairs with one burner of each pair above the other and the pairs of burners being horizontally spaced apart, valve means for controlling the supply of crude oil and compressed air to each pair of burners, a flame control water nozzle adjacent each burner, and fluid supply means for supplying oil, compressed air and water to the burner assembly, the fluid supply means for each fluid including a chamber individual to that fluid and through which the vertical axis passes, and the burner assembly and cage being supported by a fixed stand and mounted for pivotal displacement about a vertical axis relative to the stand. The, or each, fluid chamber is conveniently formed by upper and lower coupling parts. One of the coupling parts has a fixed position relative to said stand and the other coupling part has a fixed position relative to the burner assembly. The coupling part fixed relative to the stand includes a fluid inlet to chamber from a fluid supply source and the said coupling part fixed relative to the assembly includes a fluid outlet from the chamber to the burner assembly. The stand may conveniently be in the form of a pedestal with the burner assembly pivotally supported to one side so that when the pedestal is secured at a fixed location, such as a remote and safe part of an oil rig, or a boat or barge adjacent the rig, with the burner assembly in its mean position directed in the most convenient direction for the safety of the rig and attendant personnel, the assembly may be adjusted relative to the stand to accommodate variations in wind direction to maintain the safety of the rig and personnel. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described further by way of example with reference to the accompanying drawings in which: FIG. 1 shows, diagrammatically, a plan view of a burner apparatus in accordance with the invention, FIG. 2 shows, diagrammatically, a side view of the burner apparatus of FIG. 1, and FIG. 3 shows, diagrammatically, a front view of the device. DETAILED DESCRIPTION OF THE INVENTION In the drawings certain elements have been omitted for clarity but such omitted elements as are important in the operation of the device have been clearly identified and described hereunder. As will be seen from the illustrations the burner assembly is contained within a substantially rectangular protective cage 1 and the burner assembly and cage are pivotally displaceable about a vertical axis X--X 1 relative to a fixed upright stand 2. The cage 1, conveniently made from square tubing, is formed by upper and lower rectangular frames 3 and 4 respectively interconnected by front and rear uprights 5 and 6 respectively and the cage is strengthened by diagonal members 7 in frames 3 and 4 and by diagonal members 8 which extend between the frames 3 and 4. The stand 2, includes a base flange 9 with plates 10 upstanding therefrom. A duct 11, for supplying oil to the assembly, passes through the stand 2 and presents a coupling 12 to which a duct (not shown) supplying oil to the burner can be attached. A duch 13, parallel to duct 11 and with its axis in the same vertical plane as duct 11, passes through the stand 2 and presents a coupling 14 for attachment of a compressed air supply duct (not shown). A duct (not shown) with a coupling thereon, for connection with a water supply duct, will also pass through the stand 2, in identical manner to ducts 11 and 13, between and parallel to the ducts 11 and 13 and with its axis in the same vertical plane as that passing through the axis of ducts 11 and 13. This water duct through stand 2, and its connections with the water supply ducting of the assembly to be described hereafter, has been omitted only for clarity in the drawings. The duct 11, discharges into an elbow 15 the horizontal limb of which is fixed on duct 11 and the vertical limb of which opens upwardly. A coupling part 16 receives the upper open end of the vertical limb of part 15 with a fluid tight seal and part 16 is rotatable relative to part 15. The duct 13 discharges into an elbow 17, the vertical limb of which opens downwardly, and a coupling part 18 receives the lower open end of the vertical limb of elbow 17 with a fluid tight seal and part 18 is rotatable relative to part 17. In a similar manner the water supply duct (not shown) will discharge into an elbow (not shown) the vertical limb of which may open upwardly or downwardly and a coupling part (not shown) will receive the open end of the vertical limb of the elbow with a fluid tight seal, and the coupling will be rotatable relative to the vertical limb of the elbow. It will now be seen that the vertical limb of elbow 15 and the coupling 16 define an oil chamber, the duct 11 discharges into the elbow 15 and the outlet to the oil chamber is via the coupling 16. The elbow 17 and coupling 18 define a compressed air chamber into which duct 13 discharges and from which air exhausts via coupling 18. The axes of the fluid chambers defined by elbow 15 and coupling 16 and elbow 17 and coupling 18 and the chamber (not shown) defined by the water supply elbow and coupling, all lie concentric with the vertical axis X--X: The rotation of couplings 16, 18 and the water coupling is effected concentric with the axis X--X 1 and thus the supply of oil, compressed air, and water, to the assembly will be maintained for all positions of the cage 1 and the burner assembly about the vertical axis X--X 1 . The coupling 16 discharges oil from elbow 15 intoa manifold 19 which supplies oil via three valves 20, 21 and 22 to three generally upright manifolds 23, 24 and 25 respectively. Upper and lower outlets 26 and 27 respectively from manifold 23 supply crude oil to a first pair of burners 32 and 35 respectively, arranged with their axes substantially horizontally and in the same vertical plane, upper and lower outlets 28 and 29 respectively from manifold 24 supply crude oil to burners 33 and 36 respectively, arranged in like manner to burners 32 and 35, and upper and lower outlets 30 and 31 respectively from manifold 25 supply crude oil to burners 34 and 37 respectively arranged in like manner to burners 33 and 36. The burners 32, 33 and 34 lie in a common horizontal plane, the burners 35, 36 and 37 lie in a horizontal plane and, as burner pairs 32, 35 and 33, 36 and 34, 37 are controlled by valves 20, 21 and 22 respectively, each burner pair can be operated independently of the other pairs of burners. Pilots 72 are located adjacent the burners. The coupling 18 discharges into a manifold 38 which supplies compressed air through valves 39, 40 and 41 to generally upright manifolds 42, 43 and 44 respectively. Manifolds 42 and 43 are omitted from FIG. 3 for clarity in FIG. 3. The manifold 42 discharges compressed air to burners 35 and 32 via outlets 45 and 48 respectively, manifold 43 discharges compressed air to burners 36 and 33 via oulets 46 and 49 respectively and manifold 44 discharges compressed air to burners 37 and 34 via oulets 47 and 50 respectively. Outlets 45, 46 and 48 and 49 have been omitted from FIG. 3. Thus, valves 39, 40 and 41 individually control the air supply to burner pairs 32, 35 and 33, 36 and 34, 37 respectively. In a similar manner to couplings 16 and 18 the coupling for the water duct discharges into a manifold which supplies water to three ducts 51, 52 and 53 (the ducts 51 and 52 are not shown in FIG. 3) which discharge to generally upright manifolds 54, 55 and 56 respectively (manifolds 54 and 55 and their attachments are not shown in FIG. 3). The manifolds 54,55 and 56 each have two outlets to water nozzles, the manifold 56 supplies water to upper and lower nozzles 59 and 58 respectively, manifold 55 supplies water to upper and lower nozzles 60 and 60a respectively and manifold 54 supplies water to upper and lower nozzles 61 and 61a respectively. Thus, with the above described arrangement, nozzles 61, 60, 59, 61a, 60a and 58, are located adjacent burners 32, 33, 34, 35, 36 and 37, respectively and, in like manner to the oil and air supplies, the water supply to the water nozzles associated with each pair of burners can be controlled by a single valve (not shown for clarity in the drawings) independently of the other nozzles. The nozzles 61, 60, 59, 61a, 60a and 58 are so directed relative to their respective burners 32 to 37 respectively that, when operable, the water jet from each nozzle can regulate the flame, and reduce smoke, from its respective burner. It will now be seen that with the arrangement described above the burner can be operable with one, two or three pairs of burners so that the burner assembly can accommodate wide variations in the supply of oil thereto and, by adjusting the angular position of the burner assembly and cage relative to the stand, the most advantageous direction for the burner assembly can be obtained. Whilst the present invention has been described by way of example with reference to a specific embodiment many variations and modifications will be apparent to persons skilled in the art within the scope of the appended claims and, by way of example, the cage may be of different construction, the valves and fluid supply ducts may be differently arranged from that illustrated and the burner assembly can be readily made vertically adjustable and, with the valves, made adjustable under the control of servomotors.

The invention proposes apparatus for burning crude oil, particularly crude oil derived from oil wells, and which when burned on site by conventional burners can be hazardous in variable wind conditions. The invention proposes apparatus comprising a burner assembly including a plurality of substantially horizontal burners arranged in pairs, means for supplying oil for combustion and compressed air to the burners, and flame control water nozzles characterized in that the assembly is arranged for pivotal displacement about a substantially vertical axis. Thus, the direction of the flames relative to the surrounding environment can be readily adjusted to variations in wind direction.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. National Stage Application of International Application No. PCT/EP2011/055826 filed Apr. 13, 2011, which designates the United States of America, and claims priority to DE Application No. 10 2010 015 822.4 filed Apr. 21, 2010, the contents of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD This disclosure relates to a method and an apparatus for increasing the robustness of a vehicle headlight having a cylindrical prism, which in normal operation has no stop. BACKGROUND In vehicle headlights of more recent design, a plurality of stepper motors are used in order to move desired headlight parts to desired positions. It is known, for example, to use a stepper motor to regulate the headlight range of the headlight. It is furthermore already known to move a trim using a solenoid in order to switch between low beam and high beam. Furthermore, headlights with a bending light function are already known. Here, a drive is used to rotate the entire optical construction of the headlight. The rotary movement is limited in both directions by end stops. It is also known to perform driving of a trim of the headlight using a stepper motor. In this case, the trim is moved to the right or left and/or up or down. It is also already known to insert a rotatable prism horizontally into the beam path of the headlight. Such a prism is driven using a stepper motor. By rotating the prism, a more or less continuously variable transition between low beam and high beam can be realized. Such a headlight has a Hall sensor, the output signals of which are used to position the rotatable prism. In case of a defect of the Hall sensor, the rotatable prism has a stop element, using which the prism can be positioned by way of rotation at a stop counter element. The rotatability of the prism is limited by the cooperation of stop element and stop counter element. Full rotation of the prism is not possible. One example of such a rotatable prism is illustrated in FIG. 1 . It has various rotary positions. A first rotary position D 1 is associated with a symmetrical light distribution, a second rotary position D 2 with the low beam, a third rotary position D 3 with the motorway light and a fourth rotary position D 4 with the high beam of the respective vehicle headlight. Located at a fifth rotary position, provided between the rotary position D 4 that is associated with the high beam and the rotary position D 1 that is associated with the symmetrical light distribution, is the aforementioned stop element AE 1 . Switch edges SF derived from the output signal of the Hall sensor occur between the first and the second rotary position and between the third and the fourth rotary position. The aforementioned stop element AE 1 furthermore ensures during operation of the headlight that a transition from symmetrical light distribution to high beam and vice versa cannot occur. The prism PR shown is a constituent component of a vehicle headlight which additionally has a reflector R, a light source Q arranged inside the reflector, and a lens L. It is furthermore already known to capture the oncoming traffic using a camera and to maintain a switched-on high beam, but to dim that region in which oncoming vehicles are situated so as not to blind the oncoming traffic. To realize such a partial high beam, the function partial high beam is associated with a further rotary position of the rotatable prism. The exact position of the screened portion is determined by the bending light function. However, in this case the stop element AE 1 shown in FIG. 1 must be removed since not only must it be possible to change from the partial high beam to the high beam, but it must also be possible to change from the partial high beam to the low beam, where the latter change must not proceed via the high beam. One example of such a rotatable prism is illustrated in FIG. 2 . The prism PR shown by way of example in FIG. 2 is likewise a constituent component of a vehicle headlight which additionally has a reflector R, a light source Q arranged inside the reflector, and a lens L. It, too, is rotatable into different rotary positions. A first rotary position D 1 is associated with a symmetrical light distribution, a second rotary position D 2 with the low beam, a third rotary position D 3 with the motorway light, a fourth rotary position D 4 with the high beam, and a fifth rotary position D 5 with the partial high beam. The stop element AE 1 , shown in FIG. 1 , is not provided in the prism shown in FIG. 2 . Switch edges SF derived from the output signal of the Hall sensor occur between the first and the second rotary position and between the third and the fourth rotary position. The absence of the stop element shown in FIG. 1 allows—as has already been discussed—a transition between low beam and partial high beam. The prism shown in FIG. 2 operates without problems as long as the Hall sensor operates correctly and provides output signals, on the basis of which the rotary position of the prism can be ascertained. If the Hall sensor fails, however, the rotary position of the prism can no longer be ascertained. Owing to the construction of the vehicle headlight, it is also not possible in that case to set a rotary position of the prism that reliably does not blind the oncoming traffic. Although the rotary position of the prism should not change by itself owing to the detent torque of the drive of the prism, it cannot be ruled out that information relating to the instantaneous rotary position of the prism is lost on account of mechanical stress, of vibration, electrical faults, a power loss during the movement, manual interference or a cable break of a stepper motor coil. SUMMARY In one embodiment, a method is provided for increasing the robustness of a vehicle headlight, which has a cylindrical prism, which is rotatable about a rotary axis into a plurality of rotary positions using a first drive, and a Hall sensor, on the basis of the output signals of which the rotary position of the cylindrical prism is ascertainable, the method having the following steps: a check is carried out whether a defect of the Hall sensor is present, and in the event of the presence of a defect, a stop is temporarily provided and the rotary position of the prism is verified by blocking it at the provided stop. In a further embodiment, the rotatable prism is brought into a desired rotary position starting from the stop position. In a further embodiment, the stop is provided using a second drive. In a further embodiment, the stop is provided using a second drive which is present in any case and has a double function. In a further embodiment, the positioning of the cylindrical prism at the provided stop is carried out by axial displacement and subsequent rotation of the cylindrical prism. In a further embodiment, the stop for the prism is provided at an end stop of the second drive. In a further embodiment, during subsequent rotation of the cylindrical prism to the stop, a stop element provided at the cylindrical prism is positioned at a stop counter element of the end stop. In a further embodiment, the method is carried out in connection with a reference run. In another embodiment, an apparatus for increasing the robustness of a vehicle headlight comprises: a cylindrical prism, which is rotatable about a rotary axis into a plurality of rotary positions using a first drive, and a Hall sensor, on the basis of the output signals of which the rotary position of the cylindrical prism is ascertainable, wherein said apparatus has a control unit which is provided for carrying out the following steps: a check is carried out whether a defect of the Hall sensor is present, and in the event of the presence of a defect, a stop is temporarily provided and the rotary position of the prism is verified by blocking it at the provided stop. In a further embodiment, the apparatus comprises a second drive, which is used to provide the stop. In a further embodiment, the control unit is provided for bringing the rotatable prism into a desired rotary position starting from the stop position. In a further embodiment, the second drive is a drive which is present in any case and has a double function. In a further embodiment, a stop element is provided at the cylindrical prism and a stop counter element is provided at an end stop of the motor-vehicle headlight. BRIEF DESCRIPTION OF THE DRAWINGS Example embodiments will be explained in more detail below with reference to figures, in which: FIG. 1 shown an example of a known rotatable prism including a stop element, FIG. 2 shown an example of a known rotatable prism without a stop element, FIG. 3 illustrates an example cylindrical, rotatable prism according to an example embodiment, and FIG. 4 illustrates an apparatus for carrying out a method for controlling a rotatable prism, according to an example embodiment. DETAILED DESCRIPTION Some embodiment provide a method and an apparatus, in which the rotary position of the prism can be ascertained even if the Hall sensor fails. In some embodiments, if a defect of the Hall sensor occurs in a vehicle headlight, the rotary position of the cylindrical prism can be verified. This may be achieved by checking, e.g., in connection with a reference run, whether a defect of the Hall sensor is present, and, in the event of the presence of a defect of the Hall sensor, by temporarily providing a stop and verifying the rotary position of the prism by blocking it at the provided stop. If the rotary position of the prism is verified, the prism can be moved for example to a safety position, for example the low-beam position. FIG. 3 illustrates a cylindrical, rotatable prism PR, which is rotatable into different rotary positions. A first rotary position D 1 is associated with a symmetrical light distribution, a second rotary position D 2 with the low beam, a third rotary position D 3 with the motorway light, a fourth rotary position D 4 with the high beam, and a fifth rotary position D 5 with the partial high beam. At a sixth rotary position D 6 , the rotatable prism PR has a stop element AE 2 (indicated by a dashed line), which during normal operation of the headlight does not prevent full rotation of the prism PR. Switching edges SF derived from the output signal of a Hall sensor occur between the first and the second rotary position and between the third and the fourth rotary position. The prism PR shown is a constituent component of a vehicle headlight, which furthermore has a reflector R, a light source Q arranged inside the reflector, and a lens L. A check is carried out, e.g., in a reference run of the motor-vehicle headlight, whether a defect of the Hall sensor is present. In the event the presence of a defect of the Hall sensor is detected, the method can proceed to a detection of the rotary position of the rotatable prism PR, as will be explained below by way of example with reference to FIG. 4 . FIG. 4 illustrates an apparatus for carrying out a method according to an example embodiment. For providing information, from which the rotary position of the prism PR can be ascertained, a Hall sensor H is provided, whose output signals are fed to a control unit SE. Said control unit SE is provided for ascertaining, using the output signals of the Hall sensor H, the instantaneous rotary position of the rotatable prism PR and for feeding control signals to a drive Ad, such that the drive controls the rotation of the prism PR in the desired manner. The control unit SE is furthermore provided for checking whether the Hall sensor H operates correctly or is defective. If, for example, in a reference run of the headlight only output signals of the Hall sensor H with matching level (HIGH or LOW) arrive at the control unit SE during a full rotation of the cylindrical prism, the control unit SE detects that a defect of the Hall sensor H is present. The example apparatus shown in FIG. 4 furthermore has a left-side end stop AL and a right-side end stop AR of the bending light function of the vehicle headlight. If the headlight is adjusted in the context of the bending light function, the cylindrical prism PR is displaced in the axial direction, as is indicated in FIG. 4 by the arrow p. The displacement of the cylindrical prism PR to the left is limited by the end stop AL. The displacement of the cylindrical prism PR to the right is limited by the end stop AR. For such a displacement of the cylindrical prism PR in the axial direction, the control unit SE feeds control signals to a drive Ap. The rotatability of the prism PR into different rotary positions is illustrated by the arrow d. The rotatable prism PR has, on its front end, a stop element AE 2 . If the control unit SE detects that a defect of the Hall sensor is present, the prism PR is displaced axially, in a first step, in order to detect the rotary position of the rotatable prism PR, using the drive Ap in the direction of the end stop AR of the bending light function until it strikes this end stop AR. Then, in a second step, the drive Ad is used to rotate the prism PR until the stop element AE 2 of the prism PR strikes a stop counter element AG of the end stop AR of the bending light function. Starting from this stop position, the prism PR can then be rotated, under control by the control unit SE, into a desired rotary position, for example into a safety position, for example the low-beam position. In the first step, it is also possible, as an alternative to a displacement of the prism to the end stop AR, to displace the end stop AR to the prism. One advantage of certain embodiments is that the complexity for providing a stop of the prism that determines a reference position is low, because an end stop of the headlight that is present in any case, for example an end stop of the bending light function of the vehicle headlight, is used for the provision of the stop. Said end stop of the bending light function is provided with a stop counter element for a stop element of the rotatable prism, wherein the stop element of the rotatable prism does not impede the rotary movement of the prism when the Hall sensor operates without defect and wherein, after a defect of the Hall sensor has been detected, the prism is brought into an axial and rotatory stop position in order to obtain a reference position for the rotary position of the prism. From this reference position, it is then possible to change the rotary position of the prism such that a desired rotary position of the rotatable prism is assumed. A further alternative is to allow a pin provided on the cylindrical prism to move into a groove provided in the stop counter element in order to verify a reference position of the rotatable prism. Alternatively, the groove can also be provided in the prism and the pin on the stop counter element, wherein the groove has a web against which the pin abuts if the latter is located in the groove. A further alternative is for the provided stop to be represented by a solenoid. This solenoid moves for example a pin into a groove of the cylindrical prism, wherein a web in the groove represents the provided stop. Furthermore, the stop can be represented by a pin, which strikes a further pin as stop counter element. The reference position to be targeted may be provided outside the normal movement range of the headlight, for example—as stated above—directly at an end stop of the vehicle headlight. In principle it is, however, also possible for a reference position to be provided at any other location for example of the bending light function. These reference positions or stops, which in the case of a failure of the Hall sensor provide an emergency stop, also ensure protection against destruction. A further alternative is to use the drive of a headlight range control of the headlight in order to provide an emergency stop. This headlight range control moves the headlight about a horizontal rotary axis using the further drive. The stop provided using this further drive may be arranged at the bottom. This may advantageously provide that, in connection with the reference run, first a maximum downward movement is typically carried out in order to minimize the risk of blinding the oncoming traffic. Thus, the emergency stop for the prism is automatically made available without further measures. The stop provided can be provided using a single further drive or with the shared use of a plurality of drives of the vehicle headlight. One further alternative is to use sprung trims with cam disks for temporarily providing an emergency stop, which during normal operation in turn operate without stop, i.e. are rotatable through 360°.

A method is provided for increasing the robustness of a vehicle headlight comprising a cylindrical prism that can rotate about a rotary axis in a plurality of rotary positions and comprising a Hall effect sensor by means of the output signals of which the rotary position of the cylindrical prism can be determined. According to the method, a check is made as to whether a defect of the Hall effect sensor is present. In the event of a defect of the Hall effect sensor, a stop is temporarily provided and the rotary position of the prism is verified by being blocked at the provided stop.

This application is in the area of veterinary medicine and particularly a method for the prevention and treatment of fescue toxicosis. BACKGROUND OF THE INVENTION Tall fescue, grown on over 35 million acres, is the most widely spread pasture grass in humid areas of the eastern U.S.A. and, to a limited extent, in the northwestern U.S.A. It is also commonly used for vegetative cover on highway banks, parks, playgrounds, home lawns, and waterways. There are many reasons for its popularity: ease and wide range of establishment, wide range of adaptation, long grazing season, tolerance to abuse, pest resistance, good seed production, and excellent appearance when used for non-forage purposes. Tolerance of tall fescue to adverse climate, soil, and management conditions has aroused new interest and stimulated breeding and selection programs in countries such as France, Japan, Australia, New Zealand, and the USSR. With increased use of tall fescue in pastures, beginning in the 1940's, there soon were disturbing reports of poor animal performance and visible disorders. This was puzzling since digestible dry matter, crude protein, amino acid, and mineral content suggested that well managed tall fescue should give good animal performance. However, in grazing studies, beef steer gains were low, usually only about 1 lb/day for the season. Gains on tall fescue were substantially lower than on orchardgrass. With beef cattle, calf gains and cow conception rates were substantially lower on tall fescue than on tall fescue-clover. There are three principle symptoms of fescue toxicosis. The most dramatic visible symptom occurring on cattle grazing tall fescue is "fescue foot," a gangrenous condition of feet and/or tails. This syndrome appears to be related to lower ambient temperature and is much more widespread in northern than in southern parts of the tall fescue-growing region. The second syndrome of cattle grazing tall fescue is bovine fat necrosis, which is characterized by hard fat masses and abdominal fat tissue deposits, often in adipose tissue surrounding intestines, causing poor digestion and calving problems. Originally associated with heavy applications of broiler litter to tall fescue pastures, it was later found the syndrome could occur with high nitrogen fertilizer. The third and most common syndrome associated with tall fescue is "summer slump" or summer fescue toxicosis because of accentuated poor animal appearance and performance in summer. It is characterized by poor animal gains, intolerance to heat, excessive salivation, rough hair coat, elevated body temperature, nervousness, dramatically reduced weaning weights, lower milk production of both beef and dairy cows, and reduced pregnancy rate. In contrast to fescue foot and fat necrosis syndromes, summer fescue toxicosis is common and widespread throughout tall fescue-growing regions. In 1973, J. D. Robbins, a chemist at the USDA Russell Research Center in Athens, Georgia, fungal physiologist C. W. Bacon and medicinal organic chemist J. K. Porter hypothesized that a fungus might be involved in the toxic syndrome. This hypothesis was based on work in New Zealand which showed tall fescue was subject to infection by an endophyte. Sampling of pastures in Georgia and four other states led them to postulate in Appl. Environ. Microbiol. 35, 576-581 (1977), that the fungal endophyte Epichloe typhina was associated with fescue toxicosis in cattle. The endophyte was later reclassified as Acremonium coenophialum. They predicted the endophyte was seed transmitted and would die if seed were stored for 1 to 2 years. Subsequent grazing trials did not prove a cause and effect relationship, but did confirm that the fungal endophyte was associated with fescue toxicosis and that excellent animal performance could be achieved on low-endophyte tall fescue. Since the early studies that associated the endophyte with reduced animal performance, considerable research has been devoted to confirming and documenting the extent of detrimental effects of endophyte-infected tall fescue. Generally, steer ADG has been increased from 30 to over 100% by shifting from high- to low- endophyte pastures. Gain per acre has been increased to a lesser extent, probably a result of lower intake and resulting higher carrying capacity of high-endophyte pastures. Intake is 10 to 50% higher on low- than on high-endophyte hay or seed. Results of studies appear to indicate a linear relationship between endophyte level and reduction in steer gains. Stuedemann et al., J. Anim. Sci., 63 (Suppl.1), 290-291 (1986) observed a significant linear relationship between ADG and average percent endophyte, indicating that for each 10% increase in endophyte frequency, there was a 0.12 lb depression in ADG. Cattle grazing toxic tall fescue have a tendency to wallow in mud, particularly during hot times of the day, as well as spend much less time grazing than cattle on other grasses. When moved from high- to low-endophyte tall fescue, steers grazed an amount of time similar to those remaining on the high-endophyte fescue for at least 26 days following exchange, indicating that grazing high-endophyte tall fescue has a residual effect. Although intake reduction could account for much of the difference in animal performance on low- and high-endophyte tall fescue, the decreased grazing behavior even after the cattle are removed from the high endophyte fescue and systemic effects, including fescue foot and bovine fat necrosis, appeared to be a result of a toxic substance(s) present in the endophyte infested fescue. Several clinical signs of tall fescue toxicosis including increased body temperature, reduced performance, and rough hair coat could be caused by heat stress or administration of a pyrogenic substance. Inhibition of rumen microflora activity, particularly cellulolytic activity, by perloline and loline alkaloids, suggested alkaloids might be responsible. A great deal of research has now been done on various alkaloids present in toxic fescue. Although a causal relationship with fescue toxicosis has not been demonstrated, steers grazing G1-307 (an experimental, high-endophyte line with low perloline concentration and high N-acetyl plus N-formyl loline alkaloid concentration) exhibit the greatest signs of summer fescue toxicosis and have the lowest serum cholesterol concentrations, as reported by Stuedemann et al., in Am. J. Vet. Res. 46, 1990-1995 (1985). It therefore appears that toxic tall fescue influences lipid metabolism, possibly due to action by alkaloid(s) present in the grass. Few controlled grazing studies have been conducted with sheep to determine the effect of endophyte infection on animal performance. A number of studies have utilized sheep as models in controlled metabolism or physiology studies. Generally, these studies indicate responses similar to those found with cattle, though there may be magnitude differences. Controlled studies have not been conducted with horses, but tall fescue, presumably endophyte-infected, has been associated with reproductive and agalactia problems in mares. Monroe et al., J. Anim. Sci. (Suppl.1): 50 (1987), studied mares grazing endophyte-infected and endophyte-free tall fescue with and without selenium. Mares grazing infected fescue showed a greater incidence of agalactia (88%) and retained placentas (75%). There have been other case reports of high foal mortality, low conception rates and agalactia in mares grazing on fescue infected with the endophyte. At the present time, there are few options for preventing or treating fescue toxicosis. A recent estimate blames fescue toxicosis for losses by the livestock industry of between 200 million and one billion dollars per year. With high levels of endophyte infection, pasture replacement may be the preferred method for preventing fescue toxicosis. It is more difficult to assess the cost effectiveness of renovating pasture having intermediate levels of infection by the endophyte. It would be preferable to have a practical means for treating animals grazing or ingesting infected fescue with the flexibility of addressing the problem on an individual basis. It is therefore an object of the present invention to provide a method for treating fescue toxicosis in grazing animals, especially cattle, sheep and horses. It is another object of the present invention to provide a commercially useful drug and means for administering the drug which prevents fescue toxicosis in animals grazing on infected pastures or ingesting harvested infected fescue. It is a further object of the present invention to provide a method and compositions for preventing fescue toxicosis in grazing animals which do not have serious side effects or create problems with the handling or end utilization of the animals. SUMMARY OF THE INVENTION A method, and compositions, for use in the prevention and treatment of fescue toxicosis in grazing animals, especially cattle, sheep and horses, comprising administering to the animals a dopamine antagonist which does not cause behavioral modifications. The most preferred compound is metoclopramide, a substituted benzamide having the formula 4-amino-5 chloro-N-[2-(diethylamino)ethyl]-2-methoxy benzamide monohydrochloride monohydrate. Substituted benzamides including sulpiride, tiapride, alizapride, and other D 2 specific dopamine antagonists should also be useful. Care must be taken in the selection of the dopamine antagonist to avoid administration of compounds having psychotropic, neuroleptic or adverse neurological actions. The correct dosage can be determined from both the behavioral response of the animal to the compound and measurements of the serum prolactin levels, and will be expected to vary according to the animals being treated, the method of administration and the extent of endophyte infection. In the preferred method, the compound is administered to the animals orally, using capsules, timed or slow release boluses, or as an additive in a salt, trace mineral, molasses or protein block or animal feed, or as an implant. An effective dosage of metoclopramide is 15 mg/kg three times weekly when administered orally by capsule. DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph of the effect of i.v. administration of metoclopramide (0.1 and 1.0 mg/kg) on serum prolactin levels (ng/ml) over time (min) in cattle grazing on bermuda grass pasture. FIG. 2 is a graph of the effect of i.v. administration of quipazine maleate (0.01 and 0.1 mg/kg) on serum prolactin levels (ng/ml) over time (minutes) in cattle grazing on bermuda grass pasture. FIG. 3 is a graph of the effect of i.v. administration of metoclopramide (1, 2 and 4 mg/kg) on serum prolactin levels (ng/ml) over time (min) in cattle grazing on bermuda grass pasture. FIG. 4 is a graph of the effect of i.v. administration of metoclopramide (1.0 mg/kg) in combination with quipazine maleate (0.1 mg/kg) on serum prolactin levels (ng/ml) in cattle grazing on bermuda grass pasture. DETAILED DESCRIPTION OF THE INVENTION Fescue toxicosis is a condition occurring in animals grazing fescue forage infected with the fungus Acremonium coenophialum. This fungus is commonly referred to as the endophyte of tall fescue. Cattle grazing endophyte infected fescue have reduced body weight gains, reluctance to graze during periods of significant sunlight, heat and humidity and roughened haircoats at prominent signs of the condition. Physiologically, the condition is characterized by a reduction in the serum prolactin concentration. Dopamine is the major inhibitor of pituitary prolactin secretion. The putative prolactin releasing factor seems to be serotonin. It has been hypothesized that the toxins elaborated from the endophyte act as dopaminergic agonists. Previous efforts to treat fescue toxicosis have included administration of compounds affecting dopamine and serotonin levels, including dopamine antagonists, serotonin agonists, and alpha 2 -adrenergic agonists. A recent review of the neuroendocrine control mechanisms involved in fescue toxicosis is by Henson et al in Domestic Animal Endocrinology, 4(1), 7-15 (1987). Bolt et al. was among the first to report, in J. Amin. Sci. 115, 48 (1982), that plasma prolactin levels in cattle grazing on fescue were reduced. (See also W. M. Hurley et al, J. Animal Sci. 51(2), 374-379 (1981)). He attempted to alleviate the symptoms of the fescue toxicosis using butyrophenone dopamine antagonists, specifically domperidone and spiperone (8-[4-fluorophenyl-4-oxobutyl]-1-phenyl-1, 3,8-triazospiro[4,5]decan -4-one), injected i.m. three times in two days at dosages of 15, 60, 240 mg or 2.5, 10 or 40 mg, respectively. His results indicated that while prolactin levels were increased in the drug treated animals, grazing time was not significantly increased by administration of the drug. He therefore concluded that additional mechanisms were involved in fescue toxicosis. As later reported by Henson (1987), administration of spiperone to sheep caused lethargy, disorientation, and loss in body weight due to lack of appetite. Another drug, Clonidine (an alpha 2 -adrenergic agonist used by Gorewit, J. Endocrinol. Invest. 4, 135-139 (1981), who found an increased serum prolactin concentration in cattle administered 2 micrograms of clonidine/kg of body weight, i.v. However, because of ruminant sensitivity to alpha 2 -adrenergic stimulants, clonidine's potential as a therapeutic modality for fescue toxicosis at high dose levels is unfavorable. Quipazine, a serotonin agonist, (2-(1-piperazinyl) quinoline maleate) was shown by Meltzer et al. Life Sci. 19, 1073-1078 (1976) to increase plasma prolactin concentrations in rats. Subsequently, Lipham, et al., in Am. J. Vet. Res., 47 (5) 1089-1091 (May 1986), conducted a study using a synthetic ergot alkaloid CB-154 (2-bromo-alphaergocryptine), given at 0.1 mg/kg of body weight, to suppress serum prolactin concentration in rats. Rats treated with this ergot compound were given other drugs (clonidine, quipazine, LY 53857, and combinations of these 3 drugs) to prevent suppression of serum prolactin concentrations or to increase serum prolactin concentrations. A later study by Lipham et al in Proc.Soc.Exper.Biol.Med. 184,250-255(1987) reported on the effectiveness of quipazine and metoclopramide in protecting rats from CB-154 induced suppression of serum prolactin concentrations. The serum prolactin levels were shown to be most elevated using a combination of the two drugs. A quipazine-metoclopramide regimen was therefore suggested as having therapeutic potential for combating ergotlike fescue and other similar toxicities observed in cattle grazing on endophyte infected pasture grasses. A comparison of the effects of metoclopramide and quipazine, alone or in combination, on prolactin levels in cattle was conducted as follows. Pharmacologic modulation of prolactin (PRL) concentrations in yearling steers grazing bermuda grass pastures were undertaken utilizing the dopamine antagonist, metoclopramide monohydrochloride (MC), and the serotonin agonist quipazine maleate (Q). The objective was to determine whether these drugs had an effect on elevating serum PRL concentrations in steers with implications for alleviating fescue toxicosis. Dose-response relationships, routes of administration, and adverse side effects were examined. In trial I, 20 steers were randomly assigned to: MC at 0.1 or 1.0 mg/kg; Q at 0.01 or 0.1 mg/kg; or saline (S), administered i.v. (n=4). Blood samples were obtained over time for serum PRL. MC at 1.0 mg/kg resulted in a numerically increased peak PRL (28.1 vs 9.6ng/ml, MC vs S, p>0.05) and PRL was numerically elevated by MC at 220 minutes post-injection, (22.1 vs 13.1 ng/ml, MC vs S) as shown in FIG. 1. Quipazine also produced elevated prolactin levels relative to the control, as shown in FIG. 2. Importantly, however, adverse behavioral effects (disorientation, aggressiveness) were noted in animals receiving Q. In trial II, 20 steers received: 1.0 mg/kg MC and 0.1 mg/kg Q; 1.0, 2.0, or 4.0 mg/kg MC; or S by i.v. administration (n=4). The results are shown in FIG. 3 and FIG. 4. PRL was stimulated (p<0.05) for at least 480 minutes post injection. In trial III, MC was given orally. Control steers received sucrose and treated steers received 25 g MC in gelatin capsules (n=8). Post treatment, steers receiving MC had elevated peak PRL (62.7 vs. 14.6 ng/ml, MC vs controls, p<0.05) at all intervals (p<0.05) until the termination of the experiment at 24 hours. This study reemphasized the need for any useful method for treatment to take into account the behavioral as well as physiological effects of the drug. Potentially useful drugs must be screened for both using measurements of serum prolactin level in treated animals as well as observations of the behavioral effects, i.e , amount of grazing time, heat sensitivity, and presence of undesirable psychotic effects (disorientation, lack of appetite, lethargy). On the basis of the favorable results using serum prolactin and immediate abnormal behavior as the test criteria, the substituted benzamide, metoclopramide, was further studied with respect to its effect on behavior and average daily weight gain (ADG) in grazing cattle. Twenty-four yearling Angus steers were randomly assigned as pairs based on body weight to groups to examine the endocrine effects of low (approximately 25%) and high (approximately 60%) endophyte levels (percentage of the tillers examined with endophyte) and low (134 kg N.ha -1 . yr -1 ) and high (336 kg N.ha -1 . yr -1 ) nitrogen fertilization levels. These animals continuously grazed in 12, 0.7 ha paddocks along with other steers in a pt-and-take grazing system in order to maintain 1,800 kg dry matter/ha at all times. Three replicates of each group of endophyte level and N combination were made. The animals were weighed at 14 day intervals. The animals were first allowed to graze the paddocks on Apr. 9, 1987. Beginning on May 7, 1987 one of the paired steers in each paddock was orally dosed Monday, Wednesday and Friday with metoclopramide (15 mg/kg) in a gelatin capsule and the other paired steer in each paddock was given a sucrose capsule as a control. Dosing continued for 10 weeks (May 8, 1987 until July 15, 1987). On selected days, jugular cannulae were inserted, filled with Na citrate, and protected by a neck wrap. Approximately 10 ml blood was drawn at 30 min. intervals for 2 ours. Thyrotropin-releasing hormone (TRH) dissolved in saline solution was then given i.v. at 33 micrograms/100 kg body weight with blood subsequently collected at 10-min intervals for 20 min. Administration of TRH acts directly on the pituitary to cause prolactin release, thereby serving as an internal control of pituitary competency. The blood was allowed to clot at ambient temperature, placed at 4° C. overnight, and centrifuged. The serum was harvested and stored frozen at -20° C. until analyzed via radioimmunoassay for prolactin (PRL) according to the method of Wallner, et al., Amer. J. Vet. Res. 44, 1317, 1322 (1983). All serum samples from a particular date were assayed together for PRL. The results are shown in Tables I (prolactin data) and II (grazing and performance or weight gain data). TABLE I__________________________________________________________________________Mean basal prolactin (ng/ml) in metoclopramidetreated steers grazing on toxic fescue Drug Date DatePasture Treat- Tested Ratio Tested RatioGroupTreatment ment (5-28-87) (M)/(C) (6-18-87) (M)/(C)__________________________________________________________________________I. low endophyte M 65.83 58.46high nitrogen C 9.68 6.80 32.00 1.83II. high endophyte M 46.83 31.57low nitrogen C 1.34 34.95 3.35 9.42III. high endophyte M 56.00 36.58high nitrogen C 1.75 32.00 4.91 7.45IV. low endophyte M 69.51 51.42low nitrogen C 8.81 7.89 16.32 3.15__________________________________________________________________________ M = metoclopramide treated (15 mg/kg orally Mon, Wed, Fri) C = sucrose control n = 3 steers/pasture treatment group, mean of four blood samples/steer TABLE II__________________________________________________________________________Percentage time spent grazing and Cumulative ADG (averagedaily gain) in lbs/day after 10 weeks of metoclopramidetherapy in steersPasture DrugGroupTreatment Treatment % time grazing* ADG (lbs/day)__________________________________________________________________________I. low endophyte M 27.22 .759high nitrogen C 1426 .531II. high endophyte M 14.49 .684low nitrogen C 0.79 .231III. high endophyte M 21.34 .497high nitrogen C 3.61 -.122IV. low endophyte M 26.71 .827low nitrogen C 5.88 .684__________________________________________________________________________ M = metoclopramide C = sucrose control *Observation on three days from 1200-1600 h overall means (lbs/day): M .691 C .331 metoclopramide treatment significant at p = .0005 (endophyte x metoclopramide interaction significant at p = 0049; i.e., the improvement in ADG was greater in steers grazing high endophyte than low endophyte infected tall fescue) The results clearly establish that the metoclopramide treated animals are significantly (p=0.0005) more productive than the controls in terms of weight gains per day in pounds. The results also show that in drug treated animals, serum prolactin concentrations were increased by the treatment regimen of metoclopramide in comparison to their sucrose treated controls. The ratio of increase in PRL concentrations was from 1.83 to 34.95 times as great as the non-treated (sucrose) controls Further, in all instances, the metoclopramide treated animals spent more time grazing. It is apparent from these studies including behavioral observations that the effect of the medication on the animal's behavior is an important factor to take into consideration. Drugs having psychotropic or neuroleptic side effects must be avoided. Alpha 2 -adreneroic and serotonin agonists are therefore not generally useful in the treatment and prevention of fescue toxicosis in cattle. Domperidone, spiperone,.clonidine, and quipazine all have adverse behavioral effects which effectively eliminate them from use in the prevention or treatment of fescue toxicosis. This is not surprising since these compounds fall within the groups known to have neuroleptic effects that were originally developed for anti-psychosis therapy, including phenothiazines, butyrophenones, and thioxanthenes. Pyrroloisoquinolines are another recently developed group of antipsychotics. All of these compounds having psychotropic effects are thought to be specific for D 1 receptors or a combination of D 1 and D 2 receptors. At the present time, the preferred compounds are substituted benzamides such a metoclopramide (available from A. H. Robbins), sulpiride, tiapride, and alizapride. The substituted benzamides are believed to be specific for D 2 receptors. Since the ergot alkaloids are potent dopamine agonists, specifically at D 2 receptors, other dopamine antagonists specific for the D 2 receptors should be useful in a method for preventing or treating fescue toxicosis. Although initial studies were done using i.v. injections or oral administration of a capsule three times a week, these are not the preferred modes of administration on a commercial scale. The drug can instead be administered by means of a time or slow release bolus, an implant, a component of a salt, mineral, protein or energy block or feed composition. An example of a time release bolus is one presently used to deliver diflubenzuron to cattle for use in fly control (Vigilante™, manufactured by Cyanamid, NJ). The bolus remains in the animals' rumen where it slowly digests over a period of months. Biodegradable, biocompatible implants are presently in use for controlled drug delivery in humans and animals. Acceptable materials include cellulose, gelatin, polylactides, polyglycolides, polyanhydrides, polyorthoesters, polyethylene vinyl acetate, and other polymers which degrade by hydrolysis once implanted. The drug is encapsulated within the polymer using solvent casting or solution polymerization techniques. Excellent reviews of these materials are by Leong, et al. in J. Biomedical Material.Res. 19,941-955 (1985) and 20, 51-64 (1986). Non-degradable implants such as one containing morantel tartrate (worm medication) sold as Paratect™, by Pfizer Agricultural Division, NY, are also useful. Paratect™ is packaged in a capsule made of a polyolefinic sleeve, a steel ring and a permeable polyethylene disc. Another non-degradable implant in commercial use is Synovex C™, a progesterone-estradiol implant injected into the ear, manufactured by Syntex Agribusiness, Inc., West Des Moines, Iowa. The drug can also be added to a salt or mineral block during casting, or mixed into feed. An example of a drug which is presently FDA approved for administration in controlled doses to free feeding cattle is Bovatec™, manufactured by Hoffmann-LaRoche, Nutley, NJ, as described in Beef, 65-68 (October 1986). The drug can be mixed with feed or feed supplements, as with antibiotics such as Aureo S700™, manufactured by Cyanamid Animal Nutrition and Health Department, Wayne, NJ, and supplements such as Nutrena Beefcake Block, manufactured by Nutrena Feed Division, Cargill, Inc., Minneapolis, Minn or products of the Sifto Salt Division, Domtar Industries, Inc., Schiller Park, Ill. The required dosage may vary according to the mode of administration and the size and type of animal being medicated. Different results may be achieved by providing a continuous release of compound over a sustained period of time from an implant or bolus than with discrete injections or oral administration. As noted earlier, 15 mg Metoclopramide/kg per day three times a week is a safe, effective dose in cattle. Modifications and variations of the present invention, a method for prevention or treatment of fescue toxicosis, will be obvious to those skilled in the art from the foregoing detailed description of the invention. Such modifications and variations are intended to come within the scope of the appended claims.

A method, and compositions, for use in the prevention and treatment of fescue toxicosis in animals, especially cattle, sheep and horses, comprising administering to the animals a dopamine antagonist which does not cause adverse psychological or neurological effects. Useful dopamine antagonists are those specific for D 2 receptors including metoclopramide, sulpiride, tiapride, alizapride and other substituted benzamides. The preferred compound is metoclopramide, a substituted benzamide having the formula 4-amino-5 chloro-N-[2-(diethylamino)ethyl]-2-methoxy benzamide monohydrochloride monohydrate. The correct dosage can be determined from the combination of the behavioral response of the animal to the compound and by measuring the serum prolactin levels over time. In the preferred method, the compound is administered to the animals orally, using capsules, timed or slow release boluses, or as an additive in a salt, mineral, protein or energy block or animal feed, or as an implant.

Claim of Priority [0001] This patent application claims priority under 35 USC 119 (e) (1) from U.S. Provisional Patent Application Ser. No. 61/517,589 filed Apr. 22, 2011, of common inventorship herewith entitled, “Sefe Visor.” FIELD OF THE INVENTION [0002] The present invention pertains to the field of polyester film products containing images, and more specifically to the field of moving three dimensional holographic images in a clear or tinted, polarizing polymeric thin film applied to cycling helmets, visors, ski goggles, windshields, etc. BACKGROUND OF THE INVENTION [0003] The prior art has put forth several designs for cyclist helmets, and tint and image applications. Among these are: [0004] U.S. Pat. No. 5,269,858 to Gary S. Silverman describes a method of simulating stained glass art by applying liquid paints to the object which may be a glass window or sheet. The leading paint dries in approximately two to three hours and then colored paints are applied as a covering over the areas which are peripherally defined by the leading paint. [0005] U.S. Pat. No. 5,896,587 to Debra Gentry describes a bicycle helmet having a transparent eye shade and various interchangeable sun shield portions, along with affixed and built in sun shield portions. Stickers of various styles can be adhered to all eye shade portions. [0006] U.S. Pat. No. 5,035,474 to Gaylord E. Moss, Brian D. Cohn, Mao-Jin J. Chern, Lacy G. Cook, and John J. Ferrer describes a binocular holographic helmet mounted display used by pilots while flying in low light level environments. This mounted display also combines infrared or other image detection and instrumentation symbology which enhance a pilot's flight vision. [0007] None of these prior art references describe the present invention. SUMMARY OF THE INVENTION [0008] It is an object of the present invention to provide three dimensional moving photo holographic images in a clear or tinted, polarizing polymeric film for applying to sports equipment such as motorcycle helmets, windshield visors, snow goggles, windshields for motorcycles, mopeds, ATVs, dirt bikes, snowmobiles and watercraft, for example. BRIEF DESCRIPTION OF THE DRAWINGS [0009] FIG. 1 is a front perspective view showing a standard motorcycle windshield. [0010] FIG. 2 is a front perspective view showing a holographic shield design which blends with the bike's design. [0011] FIG. 3 is a front perspective view showing a holographic shield design of a skull which is distinct from the bike's design. [0012] FIG. 4 is a front perspective view showing a helmet visor shield design which blends with the helmet. [0013] FIG. 5 is a front perspective view showing a holographic shield design of a skull, which is distinct from the helmet design, on an interchangeable helmet shield. [0014] FIG. 6 is a front perspective view showing ski goggles with interchangeable lens containing different holographic designs. DETAILED DESCRIPTION OF THE INVENTION [0015] The sky is the limit for today's sport enthusiasts and athletes, and the more extreme the activity, the better. Not only do these sport enthusiasts and athletes enjoy pushing the envelope on the risks they take, but they insist on blazing a trail with a premium of individual style. Skiers and snowboarders may be bundled from head to toe, but still can be distinguished by their gear and by the graphics on their skis and snowboards. Long before the days of chopper builders on reality TV, motorcyclists always have taken pride in individually customizing their bikes, watercraft or other equipment as a personal statement. One thing that skiers, snowboarders, boaters, jet skiers and motorcyclists share is the need for clear vision and vision protection. For skiers and snowboarders the protection takes the form of goggles. For motorcyclists and boaters the protection takes the form of helmet visors and windscreens. [0016] The present invention, hereinafter referred to as the Sefe Visor, offers motorcyclists, snowboarders, boaters and skiers both vision protection and an exciting new venue for expressing individual style. The Sefe Visor is a product line of motorcycle and watercraft windscreens, helmet visors, and snowboard and ski goggles in which the optical quality polymeric matrix of the screen, goggle lens or visor bears a thin polarized film containing an embedded three dimensional moving photo holographic image. [0017] The Sefe Visor incorporates transition lens tints to adjust to strength of light or sun brightness. The image appears more vibrantly as the lens or shield darkens in bright light. The image diminishes and the shield clears with cloudiness or at night time. This image is visible to an onlooker, but does not impede or restrict the outward oriented vision of the cyclist, skier, boater or snowboarder. The Sefe Visor product embeds a moving photo holographic image in a clear or tinted, polarizing polymeric film into the helmet, visor, windshield screen for motorcycles or watercraft or goggles. The present invention combines a high quality motorcycle or watercraft windscreen, a motorcycle helmet visor or a pair of ski and snowboard goggles with the available thin film holographic technology. The consumer can apply graphic arts to their equipment. The Sefe Visor provides suggested artistic design themes from death's heads and gothic dragons to butterflies, eerie clown faces, and anime waifs. The Sefe Visor products are striking and affordable, a viable replacement for an expensive custom airbrush paint job on one's bike, skis, watercraft or snowboard. One embodiment is for the polarizing holographic polymeric films to already be affixed to the windscreens, helmet shields, or goggles, and the consumer purchases the piece of equipment with their preferred graphics. Another embodiment is for the films to be equipped with a peel and stick backing much like a tint for tinting the windows of an automobile and offered as single sheets for the consumer to apply. [0018] The Hungarian-British physicist Dennis Gabor was awarded the Nobel Prize in Physics in 1971 “for his invention and development of the holographic method”. The development of the laser enabled the first practical optical holograms that recorded 3D objects to be made in 1962 by Yuri Denisyuk in the Soviet Union and by Emmett Leith and Juris Upatnieks at University of Michigan, USA. Early holograms used silver halide photographic emulsions as the recording medium. They were not very efficient as the grating produced absorbed much of the incident light. Various methods of converting the variation in transmission to a variation in refractive index (known as “bleaching”) were developed which enabled much more efficient holograms to be produced. [0019] Several types of holograms can be made. Transmission holograms, such as those produced by Leith and Upatnieks, are viewed by shining laser light through them and looking at the reconstructed image from the side of the hologram opposite the source. A later refinement, the “rainbow transmission” hologram, allows more convenient illumination by white light rather than by lasers. Rainbow holograms are commonly seen today on credit cards as a security feature and on product packaging. [0020] Another kind of common hologram, the reflection or Denisyuk hologram, can also be viewed using a white-light illumination source on the same side of the hologram as the viewer and is the type of hologram normally seen in holographic displays. They are also capable of multicolour-image reproduction. [0021] Specular holography is a related technique for making three-dimensional images by controlling the motion of specularities on a two-dimensional surface. It works by reflectively or refractively manipulating bundles of light rays, whereas Gabor-style holography works by diffractively reconstructing wavefronts. [0022] In its early days, holography required high-power expensive lasers, but nowadays, mass-produced low-cost semi-conductor or LED lasers, such as those found in millions of DVD recorders and used in other common applications, can be used to make holograms and have made holography much more accessible to low-budget researchers, artists and dedicated hobbyists. [0023] To make a hologram, the following are required: a suitable object or set of objects, a suitable laser beam, part of the laser beam to be directed so that it illuminates the object (the object beam) and another part so that it illuminates the recording medium directly (the reference beam), enabling the reference beam and the light which is scattered from the object onto the recording medium to form an intereference pattern, a recording medium which converts this interference pattern into an optical element which modifies either the amplitude or the phase of an incident light beam according to the intensity of the interference pattern, an environment which provides sufficient mechanical and thermal stability that the interference pattern is stable during the time in which the interference pattern is recorded. [0024] An existing hologram can be replicated, either optically, similar to holographic recording or in the case of surface relief holograms, by embossing. Surface relief holograms are recorded in photoresists or photothermoplastics and allow cheap mass reproduction. Such embossed holograms are now widely used, for instance, as security features on credit cards or quality merchandise. The Royal Canadian Mint even produces holographic gold and silver coinage through a complex stamping process. The first book to feature a hologram on the front cover was The Skook (Warner Books, 1984) by J P Miller, featuring an illustration by Miller. That same year, “Telstar” by Ad Infinitum became the first record with a hologram cover and National Geographic published the first magazine with a hologram cover. [0025] The first step in the embossing process is to make a stamper by electrodeposition of nickel on the relief image recorded on the photoresist or photothermoplastic. When the nickel layer is thick enough, it is separated from the master hologram and mounted on a metal backing plate. The material used to make embossed copies consists of a polyester base film, a resin separation layer and a thermoplastic film constituting the holographic layer. [0026] The embossing process can be carried out with a simple heated press. The bottom layer of the duplicating film (the thermoplastic layer) is heated above its softening point and pressed against the stamper, so that it takes up its shape. This shape is retained when the film is cooled and removed from the press. In order to permit the viewing of embossed holograms in reflection, an additional reflecting layer of aluminum is usually added on the hologram recording layer. Embossed holograms are used widely on credit cards, banknotes, and high value products. [0027] A holographic image can be obtained using white light in specific circumstances, e.g. with volume holograms and rainbow holograms. The white light source used to view these holograms should always approximate to a point source, i.e. a spot light or the sun. An extended source (e.g. a fluorescent lamp) will not reconstruct a hologram since it light is incident at each point at a wide range of angles, giving multiple reconstructions which will “wipe” one another out. [0028] In this method, parallax in the vertical plane is sacrificed to allow a bright well-defined single colour re-constructed image to be obtained using white light. The rainbow holography recording process uses a horizontal slit to eliminate vertical parallax in the output image. The viewer is then effectively viewing the holographic image through a narrow horizontal slit. Horizontal parallax information is preserved but movement in the vertical direction produces colour rather than different vertical perspectives. Stereopsis and horizontal motion parallax, two relatively powerful cues to depth, are preserved. [0029] The holograms found on credit cards are examples of rainbow holograms. These are technically transmission holograms mounted onto a reflective surface like a metalized polyethylene terephthalate substrate commonly known as PET. [0030] Effects produced by lenticular printing, the pepper's Ghost illusion (or modern variants such as the Musion Eyeliner), and are another way to create the illusion of a 3D images on a planar surface. The Pepper's ghost technique, being the easiest to implement of these methods, is most prevalent in 3D displays that claim to be (or are referred to as) “holographic”. While the original illusion, used in theater, recurred to actual physical objects and persons, located offstage, modern variants replace the source object with a digital screen, which displays imagery generated with 3D computer graphics to provide the necessary depth cues. The reflection, which seems to float mid-air, is still flat, however, thus less realistic than if an actual 3D object was being reflected. [0031] Lenticular printing is a technology in which a lenticular lens is used to produce images with an illusion of depth, or the ability to change or move as the image is viewed from different angles. Examples of lenticular printing include prizes given in Cracker Jack snack boxes that showed flip and animation effects such as winking eyes, and modern advertising graphics that change their message depending on the viewing angle. This technology was created in the 1940s but has evolved in recent years to show more motion and increased depth. Originally used mostly in novelty items and commonly called “flicker pictures” or “wiggle pictures,” lenticular prints are now being, used as a marketing tool to show products in motion. Recent advances in large-format presses have allowed for oversized lenses to be used in lithographic lenticular printing. [0032] Photochromic lenses are lenses that darken on exposure to ultraviolet (UV) radiation. Once the UV is removed (for example by walking indoors), the lenses will gradually return to their clear state. Photochromic lenses may be made of glass, polycarbonate, or another plastic. [0033] Photohromic lenses were developed by leading glass expert Roger Araujo at the Corning Glass Works Inc. in the 1960s, and created the first mass-produced variable tint lenses. The glass version of these lenses achieve their photochromic properties through the embedding of microcrystalline silver halides (usually silver chloride), or molecules in a glass substrate. Plastic photochromic lenses rely on organic photochromic molecules (for example oxazines and naphthopyrans) to achieve the reversible darkening effect. The reason these lenses darken in sunlight but not indoors under artificial light, is that room light does not contain the UV (short wavelength light) found in sunlight. Automobile windows also block UV so these lenses would darken less in a car. Lenses that darken in response to visible (rather than UV) light would avoid these issues, but they are not feasible for most applications. In order to respond to light, it is necessary to absorb it, thus the glass could not be made to be clear in its low-light state. This correctly implies photochromic lenses are not entirely transparent, specifically they filter out UV light. This does not represent a problem, because the human eye does not see in the UV spectrum. [0034] With the photochromic material dispersed in the glass substrate, the degree of darkening depends on the thickness of glass, which poses problems with variable-thickness lenses in prescription glasses. With plastic lenses, the material is typically embedded into the surface layer of the plastic in a uniform thickness of up to 150 μm. [0035] Typically, photochromic lenses darken substantially in response to UV light in less than one minute, and then continue to darken very slightly over the next fifteen minutes. The lenses fade back to clear along a similar pattern. The lenses will begin to clear as soon as they are away from UV light, and will be noticeably lighter within two minutes and mostly clear within five minutes. However, it normally takes more than fifteen minutes for the lenses to completely fade to their non-exposed state. A study by the Institute of Ophthalmology at the University College London has suggested that even in dark conditions photochromic lenses can absorb up to 20% of ambient light. [0036] Because photochromic compounds fade back to their clear state by a thermal process, the higher the temperature, the less dark photochromic lenses will be. This thermal effect is called “temperature dependency” and prevents these devices from achieving true sunglass darkness in very hot weather. Conversely, photochromic lenses will get very dark in cold weather conditions, which makes them more suitable for snow skiers than beachgoers while outside. Once inside, away from the triggering UV light, the cold lenses take longer to regain their clear color than warm lenses. [0037] A number of sunglass manufacturers/retailers (Intercast, Oakley, Serengeti Eyewear, Persol to name a few) offer products that use photochromism to make lenses that go from a dark to a darker state. Because these products are tinted in the bleached state, they are typically used only outdoors and are not considered general-purpose lenses. [0038] See-through window graphics, technology that can be extended to this application are printed on mechanically perforated vinyl. This vinyl has a sticky adhesive on one side, protected by a peel away “release layer.” This perforated material, known as “window perf”, is made by many companies around the United States. All see-through window graphics are printed on basically the same material. The beauty of “window perf” is that it is incredibly low tech, comprised of 50% vinyl and 50% holes. Human eyes absorb light reflected from objects. When someone looks at the image on your window, their eyes absorb the light being reflected off of the printed image. The holes cannot be seen. The graphic looks like a solid image. The “sticky side” of the graphic which faces the glass, is black. Looking out from inside the vehicle, your eyes absorb light reflected off objects outside the vehicle, such as buildings, cars, trees, etc. Your eyes blend the black material on the inside with the images seen through the holes, creating the illusion that there is nothing on your window. [0039] Glass and plastic can be coated to diminish the amount of ultraviolet radiation that passes through. Common uses of such coating include eyeglasses and automotive windows. Photographic filters remove ultraviolet to prevent exposure of the film or sensor by invisible light. UV curable coatings can be used to impart a variety of properties to polymeric surfaces, including glare reduction, wear or scratch resistance, anti-fogging, microbial resistance, chemical resistance. Computer screens, keyboards, cell phone surfaces, and most other personal electronic devices are treated with some type of UV-curable coating. Coatings are usually applied to plastic substrates via spray, dip, roll, flow and other processes. UV-curable coatings are often specified for plastic parts because the process does not require heat, which can distort the plastic shape. [0040] Therefore embodiments of the present invention may be produced in the form of motor or bicycle helmet. [0041] Although this invention has been described with respect to specific embodiments, it is not intended to be limited thereto and various modifications which will become apparent to the person of ordinary skill in the art are intended to fall within the spirit and scope of the invention as described herein taken in conjunction with the accompanying drawings and the appended claims.

The invention provides dimensional moving photo holographic images in a clear or tinted, polarizing polymeric film for applying to sports equipment such as motorcycle helmets, windshield visors, snow goggles, windshields for motorcycles, mopeds, ATVs, dirt bikes, snowmobiles and watercraft, for example.

FIELD OF THE INVENTION [0001] The present invention relates to sub-sea control and monitoring, and is concerned particularly with an apparatus and a method for controlling and/or monitoring sub-sea equipment such as is used in a well. BACKGROUND [0002] Connecting to down-hole installed equipment, such as a pressure sensor and/or a temperature sensor or else to a pump, via a cable such as an electrical cable is now common in the oil business. The use of electric submersible-pump power cables and the attachment of instrumentation cables to down-hole devices have been known for many years, especially on land and in shallow water. [0003] The sub-sea environment (operations where the oil well is effectively constructed with its datum and attached pipe-work at seafloor level) presents special challenges for engineers. A sub-sea operation that could straightforwardly be undertaken on dry land has to be undertaken with specialist equipment that has failsafe modes and appropriate margins for failure of equipment. Even with the use of divers and ROVs (remotely operated vehicles), certain operations cannot be undertaken at sea floor level. [0004] During well construction, water depth usually precludes the use of fixed work platforms secured to the seabed. Instead, semi-floating work platforms (semi-submersible rigs) are floated out to the work area and either secured by chains or kept on station by satellite co-ordinated thrusters (i.e. the platforms are dynamically positioned). [0005] Since the well equipment is located on the seabed, whilst being suspended from the semi-floating platform, it is difficult to attach cables to the equipment. There is also a risk that any electrical cable or delicate equipment could easily be damaged during the installation procedure. [0006] Over the years the number of pockets of known hydrocarbon deposits that are accessible by land has diminished, and even those deposits that are accessible within shallow water are becoming scarce. Consequently, operators are moving into ever greater water depths to access oil reserves. This has led to a requirement for more complex, time consuming and costly operations to access and produce oil in deep water. At the same time, the necessary technology to monitor down-hole conditions has become more freely available. What was originally all mechanical equipment is now frequently being replaced by a combination of mechanical and sophisticated electronic monitoring equipment to optimise and monitor well conditions. Whilst the technology to develop electronic sensors and equipment robust enough to work in the harsh sub-sea environment is now available, the methods of connecting and switching the signals are still under development. [0007] As outlined above, there is a drive towards drilling in deeper, more remote waters and to monitor well conditions and performance in order to optimise return on investment. This has led to a review of operations previously considered as routine in order to save the significant increased costs of these operations or the cost of their failure in the deepwater environment. For example, the operation of installing tubular production strings (conduits for the oil) and connecting a permanent monitoring cable to a down-hole device might now take much longer on deep sub-sea wells. Previously, if the equipment was installed without cable or sensor monitoring and it was found to have failed, the equipment would be pulled back out (a so-called “work over”) and the damaged item repaired. However, in the deepwater environment, these work over (repair) costs are becoming prohibitively high. [0008] One method for monitoring and therefore controlling the well after installation requires the use of a down-hole pressure and temperature transducer (DHPTT). This is a package that is located on the lowermost end of the production tubing (string) to give a continuous read-out of well pressure and temperature. Through the acquisition of temperature and pressure information from multiple wells, an operator can control a number of wells located in the same reservoir. FIG. 1 shows a typical sub sea layout with multiple well/drill centres. [0009] The following is a description of a typical prior art “running” (i.e. installation) procedure. [0010] FIGS. 2 a to 2 e show, schematically, the various stages of running culminating in a completed installation in which the well is being permanently monitored according to a previously considered method. [0011] In FIG. 2 a the well has been constructed with the wellhead 10 prominent above the seabed 12 . It has been installed with a mechanical actuator 14 , attached on the side of the wellhead 10 , which will subsequently be used to make an electrical connection to a down-hole cable (not shown) inside the well head by penetrating through the wellhead to accommodate an electrical “wet mate” connector in a radial direction through the side of the well head. This procedure is described in detail in U.S. Pat. No. 5,558,532 (Hopper). A signal cable 16 leads from the mechanical actuator 14 to a dynamically positioned floating semi-submersible platform 18 on the surface for eventual monitoring of a down-hole device after installation. [0012] In FIG. 2 b , which depicts the next stage of the process, a tubular string 20 is lowered through the floating semi-submersible platform in short screwed-together sections. Any electronic sensors or devices are conveyed to the seabed well on this tubular string. A down-hole monitoring cable (not shown in the figure) is attached to the devices and is located within the tubular string as the assembly is lowered to the seabed. Once the calculated length of tubes is installed to fit the well depth, a ‘tubing hanger’ 22 is attached to the tubes to allow the installation to hang from a profile 26 in the sea bed known in the industry, on account of its shape, as a “Christmas tree” (a steel housing that remains at the well head and allows tubes to hang and valves to be attached). The tubing hanger 22 and tubing 20 are conveyed to the “tree” at sea floor by a releasable latch known as a tubing hanger running tool 24 . This is attached to a profile in the tubing hanger 22 and the entire assembly (string) is then conveyed to the sea floor by adding lengths of screwed tubing until the tubing hanger reaches and engages the tree. This is a standard procedure. [0013] FIG. 2 c shows the running tool after it has just been disconnected. The running tubes can now be retrieved to the surface. [0014] FIG. 2 d depicts a remote-operated vehicle (ROV) 28 mechanically turning the actuator 14 that pushes forward the wet mate horizontal connector to make a permanent connection to the down-hole devices via the down-hole cable. [0015] FIG. 2 e shows the final configuration when the well is complete and the permanent monitoring cable 16 is commissioned to a final vessel or semi-floating work platform. [0016] In view of the high costs of repair work in the deep sea environment, as outlined earlier, there is a strong incentive to monitor equipment to check that it is functioning during installation, in order to avoid the need for a costly work over. Thus, a device that is developed as part of the installed sub sea well head that allows electrical signals to be switched from monitoring whilst running (i.e. whilst installing) to permanent monitoring (i.e. after installation) is desirable, especially in the arduous sub sea environment. [0017] One disadvantage of the prior system, as outlined above with reference to FIG. 2 , is that the process does not permit monitoring of the down-hole device during installation (running). SUMMARY [0018] The present invention is defined in the attached independent claims, to which reference should now be made. Further, preferred features may be found in the sub-claims appended thereto. [0019] In one aspect, the invention provides a system for monitoring and/or controlling at least one device mounted on a tubing string of a well, the system comprising: a down-well cable for conveying a signal to and/or from at least one device mounted on a tubing string of a well; a temporary surface cable for conveying a signal between the at least one device and a first monitor/control station prior to and/or during installation of a tubing string in a well; a permanent surface cable for conveying a signal between the at least one device and a second monitor/control station after installation of the tubing string in a well; and switch means configurable between a first configuration, in which the down-well cable and the temporary cable are connected, and a second configuration, in which the down-well cable and the permanent cable are connectable. [0020] The invention also provides switch means for use in switching a signal from at least one device mounted on a tubing string of a well, the switch means being configurable between a first configuration, in which a down-well cable, for conveying a signal from/to at least one device mounted on a tubing string of a well, and a temporary surface cable for conveying a signal between the at least one device and a first monitor/control station prior to and/or during installation of a tubing string in a well are connected, a nd a second configuration, in which the down-well cable and a permanent surface cable for conveying a signal between the at least one device and a second monitor/control station after installation of the tubing string in a well are connectable. [0021] The invention also provides a method of monitoring and/or controlling at least one device mounted on a tubing string of a well, the method comprising: monitoring and/or controlling said device via a temporary surface cable connected to a down-well cable and arranged to convey a signal between the at least one device and a first monitor/control station prior to and/or during installation of the tubing string in the well, in a first configuration; monitoring and/or controlling said device via a permanent surface cable connected to the down-well cable and arranged to convey a signal between the at least one device and a second monitor/control station after installation of the tubing string in a well, in a second configuration; and switching between the first and second configurations. [0022] The invention also provides a system for monitoring and/or controlling at least one device mounted on a tubing string of a well, the system comprising: a down-well cable for conveying a signal to and/or from at least one device mounted on a tubing string of a well; a temporary surface cable for conveying a signal between the at least one device and a first monitor/control station prior to and/or during installation of a tubing string in a well; and switch means configurable between a first configuration, in which the down-well cable and the temporary cable are connected, and a second configuration, in which the down-well cable and the temporary cable are not connected. [0023] The invention also includes any combination of the features or limitations referred to herein, except combinations of such features as are mutually exclusive. BRIEF DESCRIPTION OF THE DRAWINGS [0024] FIG. 1 shows schematically a modern sub-sea oilfield comprising a number of wells with monitoring cables connected to a floating station, [0025] FIGS. 2 a to 2 e show schematically a series of steps for installing a tubing string in a sub-sea well and monitoring signals from sensors on the string, according to a prior art method, [0026] FIGS. 3 a to 3 e show schematically a series of steps for installing a tubing string in a sub-sea well and monitoring signals from sensors on the string, according to a preferred embodiment of the present invention, [0027] FIG. 4 a shows schematically switching means in a first configuration, according to a first embodiment of the present invention, [0028] FIG. 4 b shows schematically the switching means of FIG. 4 a in a second configuration, [0029] FIG. 5 a shows schematically switching means in a first configuration, according to a second embodiment of the present invention, [0030] FIG. 5 b shows schematically the switching means of FIG. 5 a in a second configuration, [0031] FIG. 6 a shows schematically switching means in a first configuration according to a third embodiment of the present invention, [0032] FIG. 6 b shows schematically the switching means of FIG. 6 a in a second configuration, and [0033] FIGS. 7 a and 7 b show one example of the construction of a switching means suitable for use in the above-described embodiments. DETAILED DESCRIPTION [0034] Turning now to FIGS. 3 a to 3 e , these show schematically the various stages of running culminating in a completed installation in which the well is being permanently monitored in accordance with a preferred embodiment of the present invention. Where possible, features common with the prior art example of FIGS. 2 a to 2 e have been given the same reference numbers. [0035] In FIG. 3 a , as before, the well has been constructed with the wellhead 10 prominent above the seabed 12 . It has been installed with a mechanical actuator 14 , attached on the side of the wellhead 10 , which will subsequently be used to make an electrical connection to a down-hole cable (not shown) inside the well head by penetrating through the wellhead to accommodate an electrical “wet mate” connector in a radial direction through the side of the well head. A permanent cable 16 leads from the mechanical actuator 14 to a dynamically positioned floating semi-submersible platform 18 on the surface for use in monitoring a down-well device permanently after installation. The permanent cable 16 is a surface cable in that it is above the well. It could, of course, lead to a monitoring station below the surface of the sea. [0036] In FIG. 3 b , which depicts the next stage of the process, a tubular string 20 is lowered through the floating semi-submersible platform in short screwed-together sections. Any electronic sensors or devices are conveyed to the seabed well on this tubular string. A down-hole monitoring cable (not shown in the figure) is attached to the devices and is located within the tubular string as the assembly is lowered to the seabed. Once the calculated length of tubes is installed to fit the well depth, a tubing hanger 22 is attached to the tubes to allow the installation to hang from a tree profile 26 in the sea. The tubing hanger 22 and tubing 20 are conveyed to the “tree” at sea floor by a releasable latch known as a tubing hanger running tool 24 . This is attached to a profile in the tubing hanger 22 and the entire assembly (string) is then conveyed to the sea floor by adding lengths of screwed tubing until the tubing hanger reaches and engages the tree. [0037] In contrast with the prior art, the present invention makes possible the monitoring of the equipment during running. To achieve this, the tubing hanger contains through bores that accommodate a vertical electrical connector that is connected to a temporary monitoring cable 34 for monitoring the down-well device during (installation) running. The monitoring cable 34 is attached via clamps (not shown) adjacent to the running tool tubing all the way to the surface. [0038] FIG. 3 c shows the running tool after it has just been disconnected. The running tubes and temporary monitoring cable 34 can now be retrieved to surface. [0039] By use of switch means described in detail with reference to FIGS. 4 to 7 , the connection between the temporary monitoring cable 34 and the down-well cable (not shown) has been opened, whilst a new connection between the down-well cable and the permanent monitoring cable 16 has been prepared, awaiting only actuation of the wet-mate connector by the actuator 14 . [0040] FIG. 3 d depicts a remote-operated vehicle (ROV) 28 mechanically turning the actuator that pushes forward the wet mate horizontal connector to make a permanent connection to the down-hole devices via the down-hole cable. [0041] FIG. 3 e shows the final configuration when the well is complete and the permanent monitoring cable 16 is commissioned to a final vessel or semi-floating work platform. [0042] FIGS. 4 to 7 will now be referred to as embodiments of the invention are described in more detail. [0043] Referring now to FIG. 4 a , this shows generally a well head 32 during installation of a tubing hanger 22 . The tubing hanger 22 is still attached to the tubing hanger running tool 24 and has engaged the tree 26 . A temporary monitoring cable 34 extends upwards through the tubing hanger running tool 24 to monitoring apparatus located at the surface (not shown). A down-well monitoring cable 36 extends downwards inside the tubing hanger 22 through the tubing string (not shown) to down-well sensor equipment. The temporary cable 34 and the down well cable 36 are connected by a spring-loaded switch 38 . To the side of the tree 26 is a wet mate connector 40 having a mechanical actuator 14 . Inside the tubing hanger 22 and connected to an unused contact of the switch 38 is a short cable portion 42 shown in broken lines. The short cable portion leads from the switch to a horizontal wet mate pin 44 which is arranged in use to engage and make electrical contact with a female wet mate connector portion 46 upon actuation by the mechanical actuator 14 . [0044] The switch 38 comprises a first contact position in which the down-well monitoring cable 36 is in electrical contact with the temporary monitoring cable 34 , and a second contact position in which the down-well monitoring cable is in electrical contact with the short cable portion 42 . A compression spring 38 a is located within the switch between the first and second contact positions. In the configuration shown in FIG. 3 a the presence of the tubing hanger running tool 24 in engagement with the tubing hanger 22 biases the switch 38 in the position shown by means of a switch pin 48 (shown more clearly in FIG. 4 b ) compressing the switch spring 38 a . [0045] FIG. 4 b shows the well head immediately after the tubing hanger running tool 24 has disengaged from the tubing hanger 22 . Upon withdrawal of the switch pin 48 the compression spring 38 a biases the switch 38 in the second configuration (shown) in which the down-well monitoring cable 36 is no longer connected to the temporary monitoring cable but is now connected to the short cable portion 42 . In this figure the mechanical actuator 14 has also been operated to cause the female wet mate connector 46 to make electrical contact with the horizontal wet mate pin 44 , thereby allowing monitoring signals from the down-well cable 36 to be taken out of a permanent monitoring connection 50 , which is connected via a permanent monitoring cable (not shown) to a permanent monitoring station on the surface or on land. [0046] If the tubing hanger running tool 24 is reconnected to the tubing hanger 22 , the switch pin 48 will cause the switch 38 to become biased in the first configuration, with the down-well monitoring cable becoming reconnected to the temporary monitoring cable 34 in the tubing hanger running tool. The process can be repeated as often as necessary and each time the reversible connections will be made reliably and cleanly. [0047] FIGS. 5 a and 5 b correspond to FIGS. 4 a and 4 b respectively, but in this case the biasing spring 38 a is at a location spaced from the switching contacts. [0048] Similarly, FIGS. 6 a and 6 b correspond to FIGS. 4 a and 4 b , but in the embodiment shown in FIGS. 6 a and 6 b there is a second spring-loaded switch 52 which is moveable between the position shown in FIG. 5 a , in which the wet mate connector has not yet been actuated and the switch 52 is biased by a compression spring 52 a to connect the down-well monitoring cable via the short cable portion 42 to the temporary monitoring cable, and a second position shown in FIG. 5 b in which the wet mate connector has been actuated and the switch 52 connects the down-well monitoring cable to the permanent monitoring cable 50 . [0049] In a further embodiment, which may utilize the switch means of any of FIGS. 4 to 6 , the switch pin 48 is retractable into the tubing hanger running tool 24 . Thus, in this embodiment, when the tubing hanger running tool 24 is connected to the tubing hanger 22 , the switch pin 48 will normally cause the switch 38 to become biased in the first configuration, with the down-well monitoring cable 36 being connected to the temporary monitoring cable 34 in the tubing hanger running tool. When the switch pin 48 is retracted inside the tubing hanger running tool 24 , however, the compression spring 38 a biases the switch 38 in the second configuration (shown) in which the down-well monitoring cable 36 is no longer connected to the temporary monitoring cable. In this way, switching between the first and second configurations can be performed without needing to disengage the tubing hanger running tool from the tubing hanger. Advantageously, this enables the temporary monitoring cable 34 to be disconnected from the down-well monitoring cable 36 before the tubing hanger has engaged with the tree 26 . Then, by electrically isolating the retracted switch pin, electrical testing can be performed on the temporary monitoring cable. In this way, if a fault develops before the tubing hanger has reached the sea bed, testing can be performed to determine if the fault is in the temporary monitoring cable or in the permanently installed equipment. [0050] FIGS. 7 a and 7 b show one example of the construction of a switching means suitable for use in the above described embodiments. [0051] The switching means comprises the spring-loaded switch 38 having a housing 90 in which is contained a contact ring 100 , the compression spring 38 a and a shuttle body 110 having two parts 110 a and 110 b , each connected to one end of the compression spring. The down-hole monitoring cable 36 is permanently connected to the contact ring 100 . In FIG. 7 a , the switch is in the first contact position, in which the switch pin 48 provided at the end of the temporary monitoring cable 34 is in contact with the contact ring 100 . In this first configuration, the compression spring is biased in a compressed state. [0052] In FIG. 7 b , the tubing hangar running tool has been disengaged from the tubing hangar, or the switch pin has been retracted into the tubing hanger running tool, such that the switch pin 48 of the temporary monitoring cable 34 has become disconnected from the contact ring 100 . The compression spring 38 a now biases the switch 38 in the second configuration, in which the shuttle body 110 a makes contact with the contact ring 100 . This completes the circuit across the switch 38 , through the shuttle body part 110 a , the spring 38 a and the shuttle body part 110 b , such that the down-hole monitoring cable 36 is now electrically connected to the short cable portion 42 leading to the permanent monitoring connection 50 . [0053] There are various other means (not shown) of switching in this environment and location. It is possible to use a diode to isolate each line electronically without using a mechanical device. However, due to the electrical properties of a diode in the reverse direction, the current that passes through the diode in the reverse direction may be too great for satisfactory performance and integrity testing when the current and voltage are low (instrumentation level installation). The switching could be achieved by the use of a solenoid. Alternatively, the switching could be achieved via a contact-less method where no horizontal actuator was needed through the use of magnetic induction or other matching sensors that line up and transfer the current. [0054] An ROV (remotely operated vehicle) or a diver can rotate the mechanical actuator so as to extend the female wet mate connector horizontally to connect to the horizontal male wet mate connector. This connects the electrical signal to the permanently installed monitoring line. [0055] One advantage of the system outlined above with reference to FIGS. 3 to 7 is that the process is reversible i.e. even after the temporary monitoring cable 34 on the tubing hanger running tool has been disconnected from the down-hole cable in the tubing hanger it remains possible to re-connect it. Re-connection might be desirable if, for example, a fault were to be detected during permanent—i.e. post-installation—monitoring. In such a case, being able to lower the tubing hanger running tool and re-connect the temporary monitoring cable to the down-well cable might allow an operative to determine whether the fault is with the down-well sensors or else with the wet-mate connector, or even with the permanent monitoring cable itself. During installation (“running”) it is not uncommon for the tubing hanger running tool to be disconnected and reconnected several times if problems are encountered in engaging the tubing hanger with the tree or if unsatisfactory or puzzling readings are detected. In such cases the ability to disconnect and reconnect the temporary monitoring cable provides an advantage. [0056] Furthermore, switching may be performed by retracting the switch pin into the tubing hanger running tool, without needing to disconnect the tubing hanger running tool from the tubing hanger. In this way, testing can be performed before the tubing hanger has engaged with the tree. [0057] Reversible switching of an electrical signal in the complex, permanently installed well head hanger has previously not been undertaken and has the potential to save sub sea well operators significant amounts of time by avoiding remedial work. The integrity of the cables and the functioning of the down-hole devices can now be monitored throughout installation and thereafter with immediate feedback, and the operator has the option of reconnecting to a temporary monitoring cable by reconnecting the tubing hanger running tool. [0058] Whereas the specification speaks mainly of using electrical cables and electrical switch means to monitor and/or control down-well devices, it will be understood that the invention is equally applicable to the use of optical cables and electrical switches. [0059] Also, whilst the embodiments described are concerned with sub sea oil wells, it will be understood that the invention is equally applicable to other kinds of wells such a gas wells. [0060] Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying suitable modifications and equivalents that may occur to one skilled in the art and which fairly fall within the basic teaching herein set forth.

A system for monitoring and/or controlling at least one device mounted on a tubing string of a well, the system comprising: a down-well cable for conveying a signal to and/or from at least one device mounted on a tubing string of a well; a temporary surface cable for conveying a signal between the at least one device and a first monitor/control station prior to and/or during installation of a tubing string in a well; a permanent surface cable for conveying a signal between the at least one device and a second monitor/control station after installation of the tubing string in a well; and switch means configurable between a first configuration, in which the down-well cable and the temporary cable are connected, and a second configuration, in which the down-well cable and the permanent cable are connected.