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RELATED APPLICATIONS [0001] This is a utility patent application filed under 35 U.S.C. 111(a) and claiming the benefit under 35 U.S.C. 119(e)(1) of the filing date of provisional application Ser. No. 60/835,791 filed on Aug. 4, 2006 BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates in general to a golf swing plane training device, and more particularly to a golf swing plane training device that comprises a rotating swing plane guide, one end pivotably connected to a golf club shaft, for constraining and controlling the swing arc of the golf club shaft when swung by a golfer to ingrain the feel of swinging on plane and consequently develop a correct golf swing. [0004] 2. General Background [0005] Golf is a sport that has a centuries-long history and has been studied exhaustively by devoted golfers in their quest to understand and master the fundamentals of the golf swing mechanics. There is a constant stream of instructions in the form of books, videos and magazine articles on various elements of the golf swing, such as grip, stance, posture, steps of the swing (backswing, downswing and follow-through) and swing plane. Likewise, there is also a steady flow of training devices being created to help golfers tackle specific aspects of the golf swing. Of all the elements, the concept of the swing plane may possibly be the most complicated to grasp. [0006] It is generally acknowledged that one must swing “on plane” to produce a good golf shot. However, many golfers do not have a clear understanding of what the swing plane is and what it is that should be on this plane. The primary reason for this difficulty is that a golf swing is a dynamic motion in a three-dimensional space that lasts only a second or two. It is infeasible for a golfer to observe or check his/her own swing plane in real time; the viewing of one's own swing can only be done using high-speed video or sequence photograph that captures the swing in a two-dimensional space. Furthermore, other referential concepts intended to help golfers gain understanding may be misinterpreted by some. For instance, there is the “shaft plane”, defined as the imaginary line that runs through the club shaft as it sits at address, and the “Hogan plane”, which is an imaginary pane of glass extending from the ball to the golfer's shoulders. Conceptual planes like these serve as valuable checkpoints of a golfer's swing at discrete steps; however, they do not describe the plane the club travels on throughout a golf swing. [0007] Put simply, a correct golf swing requires the club shaft be swung on substantially the same plane on both the backswing and the downswing. If one could observe the trail of a marker on the club shaft made during a swing, it would correspond to an elliptical arc. The arc is not circular as the golfer does not pivot around a central point through the entire swing. Hips, arms, elbows, wrists, etc. are all pivot points that are activated at different moments during the swing. Also, this elliptical arc flattens further as the swing approaches the end of the backswing, i.e., the top of the swing. Furthermore, as the downswing is initiated with a slight lower-body shift toward the target coupled with a lowering of the right shoulder and elbow (for a right-handed golfer), the elliptical arc of the downswing, if it could be observed, would be narrower than that of the backswing and likely on a slightly flatter plane. Therefore, a correct golf swing requires the downswing be on the same plane as, or a slightly flatter plane than, that of the backswing. For a normal golf shot, when the golfer is not attempting to shape the ball flight, the downswing should not be on a steeper plane than that of the backswing, which tends to lead to the dreaded “outside-in” move not conducive to a good golf shot. [0008] Finally, there is not a singular “ideal” swing plane that is suitable for all golfers. The plane angle, which is the angle between the swing plane and the ground, varies amongst golfers depending on many factors such as height, body build, arm length proportion, spine tilt at address, etc. Additionally, for each golfer, the plane angle also varies depending on the length of the particular club being used for a golf shot and the position of the ball, i.e., the lie. As to the arc of the swing, it should be narrower on the downswing. However, the degree again differs amongst golfers depending on factors such as the amount of lower-body forward shift, ability to retain a full wrist cock on the downswing, etc. These are natural and perfectly acceptable variations; there is no singular ideal swing that all golfers should be forced to imitate. [0009] Perhaps to a greater extent than other aspects of the golf swing, the golfer must rely on the proper feel, or muscle memory, to keep his/her swing on plane. Even with a sound understanding of the concept, it is difficult for a golfer to work on his/her swing plane without the assistance of an instructor or a training device. Many training devices have been conceived over the years to help golfers “groove” their swing and develop the desired muscle memory. These devices fall generally into three categories. One category of training devices concentrate on constant- or variable-force resistance training of the specific muscles involved in the golf swing (backswing, downswing or follow-through), and secondarily on swing plane training. Most of these devices employ a handle connected to a flexible cord which, in turn, is connected to a resistance mechanism. The resistance force discourages, but not constrains, the user from making an abrupt, jerky movement when transitioning from backswing to downswing. Also, the flexible cord exerts little control over the path of the movement of hands or the swing plane. A second category of training devices use tracks or rails to lay out a predetermined, fixed path for a real or simulated golf club. Some devices mandate the exact same plane for both the backswing and the downswing. Others construct a narrower or flatter, but fixed and non-adjustable, path for the downswing. That is to say, most of these devices do not take into account the perfectly allowable variations in golfers' swings. Also, these devices are outsized, difficult to transport, and tend to be expensive to manufacture. [0010] A third category of training devices employ a rotating swing arm, typically a rod, which constrains and guides the motion of a real or simulated golf club. Some also include a resistance mechanism for muscle strength training. The present invention fits in this general category. Examples include: U.S. Pat. No. 2,737,432, G. M. T. Jenks; U.S. Pat. No. 3,429,571, R. Abel, Jr.; U.S. Pat. No. 3,604,712, A. P. Lansing, et at.; U.S. Pat. No. 3,614,108, E. Garten; U.S. Pat. No. 4,261,573, R. H. A. Richards; U.S. Pat. No. 4,449,708, M. N. R. Humphrey; U.S. Pat. No. 4,486,020, B. T. Kane, et al.; U.S. Pat. No. 4,580,786, B. E. Shipley; U.S. Pat. No. 4,653,757, K. E. Wilkinson; U.S. Pat. No. 5,125,882, T. A. La Mothe, et al.; and U.S. Pat. No. 5,242,344, K. W. Hundley. While these devices take a similar approach as the present invention, each has one or more of the following drawbacks. (1) The device comprises a rotating rod fixedly connected to a club shaft, restricting the club shaft to move along the same circular arc on both the backswing and the downswing. As the golf swing does not naturally follow a circular arc, the device restricts the golfer from getting full extension in the middle of the backswing and forces the golfer to lift the club or swing around his/her body toward the top of the swing. (2) The club shaft is restricted to move only on the same swing plane throughout the swing. This forces some golfers to unnecessarily alter their swing. (3) The distal end of the rod not connected to the club shaft is anchored on a vertical support; the rod freely rotates or pivots relative to the anchor. No means is provided to adjust the angle of the swing plane. (4) The rotating swing arm is a flexible tension member or a telescoping rod that does not restrict the club shaft from moving on a steeper swing plane on the downswing. (5) Dissimilar shapes are involved where the club shaft is attached to the rotating rod, creating friction and hampering smooth motion transmission. For instance, the square clubface is attached to a telescoping rod, or the tapered club shaft is fastened with a ring nut. (6) The device does not allow the user to make a full swing as the rod would not clear his/her head. (7) The device is too complicated or too expensive to manufacture to be economically viable. (8) The device is outsized or requires being anchored on an opposing wall, thus is not transportable. [0011] There exists a need for a golf swing plane training device which comprises a rotating swing plane guide, one end pivotably connected to a golf club shaft, for constraining and controlling the swing arc which is asymmetrically elliptical, while allowing for natural variations in golfers' swings but restricting improper swing plane changes. BRIEF SUMMARY OF THE INVENTION [0012] The present invention relates to a golf swing plane training device that also serves as an exercising device to help the user develop the muscle memory of swinging on plane as well as exercise the muscle groups most effective in imparting maximum power to a golf ball. The device is portable and comprises a rotating swing plane guide, one end pivotably connected to a golf club shaft, for constraining and controlling the swing arc of the golf club shaft when swung by the user to ingrain the feel of swinging on plane and consequently develop a correct golf swing. The other end of the rotating swing plane guide is connected to a rotation control assembly. A resistance source is connected to the hub of the rotation control assembly to provide resistance force against the club shaft on the downswing, strengthening the muscle groups that need be activated to maximize power and intensifying the proper feel of a correct swing. [0013] One object of the present invention provides a golf swing plane training device that is relatively compact is size and is realistically portable. The device is collapsible; it can be set up at a suitable location for a practice session, and then folded into a storage configuration. [0014] Another object of the present invention provides a golf swing plane training device that includes a rotation control assembly mounted on a vertically adjustable support frame. The rotation control assembly is set at an angle that is adjustable, but fixed during operation. This angle determines the axis of rotation and, thus, the angle of the swing plane. The adjustability of the height of the device and the plane angle allows the device to be used by all golfers. [0015] A further object of the present invention provides a golf swing plane training device having a swing plane guide which comprises a rotatable, largely concave swing arm to constrain and restrict the club shaft from moving down on a swing plane steeper than that of the backswing. The curved shape of the swing plane guide allows it to clear the user's head when the swing is approaching the top of the swing or the end of the follow-through. The swing plane guide further comprises a radius adjustment assembly, connected to the swing arm, which includes a linear track having an axis perpendicular to the swing plane axis of rotation. A universal pivoting assembly is employed to connect a golf club shaft to the swing arm via a carriage slidably disposed on the linear track. Thus, the golf club shaft is not connected to the swing plane guide at a fixed point, which would force the golf club shaft to follow a circular swing arc. The connecting point is at the carriage which is free to slide along the linear track, and the golf club shaft can follow a swing arc that flattens toward the top of the swing. [0016] Still a further object of the present invention provides a golf swing plane training device that employs a universal joint for connecting the golf club shaft to the swing plane guide, allowing the club shaft to pivot freely relative to the swing plane guide and to slide within the universal joint. Hence, the swing arc is not limited to strictly follow a circular shape, and the swing arc can be extended on the backswing and narrowed on the downswing by varying degrees as is natural to different golfers. Furthermore, the radius adjustment assembly includes a swing plane varying assembly which extends and retracts axially, allowing the user to initiate the downswing on a slightly flatter swing plane. [0017] Yet one further object of the present invention provides a golf swing plane training device that contains a resistance source for exercising the muscle groups which are most effective in transferring maximum power to a golf ball. The resistance force preferably is only engaged on the downswing and is disengaged on the backswing, as the goal during the backswing is to achieve smooth motion and full extension in order to maximize leverage. [0018] These and other objects of the present invention will become apparent after a reading of the following description and accompanying drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING [0019] FIG. 1 is a perspective view of the preferred embodiment of the golf swing plane training device constructed in accordance with the present invention. [0020] FIG. 2 is a side elevational view of the device shown in FIG. 1 . [0021] FIGS. 3 a - 3 d are a series of perspective views of the device shown in FIG. 1 showing the device at various stages when a user (omitted from the illustration) swings the simulated golf club from the at-rest position to the top of the swing. [0022] FIG. 4 a is an enlarged front perspective view of the rotation control assembly and the resistance mechanism (and a partial portion of the swing plane guide) of the device shown in FIG. 1 , with the hub housing and the stand omitted from the illustration. [0023] FIG. 4 b is an enlarged rear perspective view of the rotation control assembly and the resistance mechanism (and a partial portion of the swing plane guide) of the device shown in FIG. 1 , with the hub housing and the stand omitted from the illustration. [0024] FIG. 5 a is a partial perspective view of the swing plane guide and the simulated golf club of the device shown in FIG. 1 . [0025] FIG. 5 b is an enlarged perspective view of the radius adjustment assembly of the device shown in FIG. 1 , with the support member omitted from the illustration. [0026] FIG. 5 c is an enlarged perspective view of the radius adjustment assembly of the device shown in FIG. 1 oriented for the top of the backswing or the beginning of the downswing. [0027] FIG. 5 d is an enlarged perspective view of the radius adjustment assembly of the device shown in FIG. 1 oriented for the beginning of the downswing, showing the rod extending axially at the initiation of the downswing. [0028] It is to be understood that like elements are identified throughout the drawings with like reference numerals. DETAILED DESCRIPTION OF THE INVENTION [0029] The golf swing plane training device according to the concepts of the present invention and how it functions can best be explained by reference to the attached drawings. As illustrated in FIG. 1 , the preferred embodiment of the golf swing plane training device 10 comprises a base member 20 , a support frame 30 , a rotation control assembly 40 , a swing plane guide 50 , a simulated golf club 70 , and a resistance mechanism 80 . [0030] Referring now to FIG. 2 , the base member 20 consists of a base platform 21 that is generally rectangular in shape for supporting and positioning the user by standing on it. The weight of the user standing on the base platform 21 serves to stabilize the device. The upright support frame 30 consists of a lower support portion 31 and an upper support portion 32 . The upper support portion 32 is vertically adjustable such that the height of the device can be altered to suit the user's stature. The adjustment can be implemented using any conventional means suitable for the type of material used to fabricate the support frame 30 . Suitable adjustment means include locking pins or bolts that extend through a hole in the lower or upper support portion 31 and one of a plurality of vertically spaced holes in the upper or lower support portion 32 , or twist locks commonly used on tripod legs. The support frame 30 preferably is curved, approximately corresponding to the shape of the swing plane guide 50 that will be detailed later, so as to make the device more compact and portable. While curved vertical columns with cross bars are illustrated in the drawings, it will be understood that the support frame 30 can take on differing shapes without affecting its function of upholding the rotation control assembly 40 , the swing plane guide 50 and the resistance mechanism 80 . The support frame 30 is affixed to the base member 20 via any one of a number of securing mechanisms suitable for the material used and generally well known in the art, such as clamping knobs, fasteners or screws. The illustrations show the support frame 30 being attached to a base frame 22 extending from and welded or otherwise attached to the base platform 21 . The purpose of the base frame 22 is to reduce the mass of the base member 20 to aid in the portability of the device. It is to be understood that the support frame 30 can alternatively be directly affixed to a larger-sized base platform. The support frame 30 preferably can be released from the base frame 22 and folded for storage. Additional appendages such as a handle and wheels can be added to the base member 20 to further make the device easy to transport when in the collapsed configuration. [0031] As illustrated in FIGS. 1 and 2 , the rotation control assembly 40 comprises a hub 41 , which is a shaft for driving other components of the device, rotatably seated on a hub housing 42 pivotably mounted on a stand 43 affixed to the support frame 30 . Preferably, the stand 43 is releasably affixed to the support frame 30 so the device can be more easily collapsed and folded into a storage configuration. Any conventional fastening means that is commonly known, such as the clamping knobs illustrated in the drawings, may be used. The hub 41 extends beyond both ends of the hub housing 42 for connecting and driving other components that will be described later. The hub 41 rotates about an axis A that defines a swing plane axis of rotation as will be described below. Preferably, at either end of the hub housing 42 around the opening through which the hub 41 extends, a ring of roller/ball bearings are employed and sandwiched between an inner race (affixed to the hub 41 ) and an outer race (affixed to the hub housing 42 ) such that the hub 41 can freely rotate with minimal rotational friction with the hub housing 42 . The incline of the rotation control assembly 40 is adjustable, but fixed during operation of the device. By altering this angle as shown by angle B, the swing plane axis about which the device rotates during use is set at a desired angle of inclination, B, which also means the angle of the swing plane, being perpendicular to the axis of the hub 41 , is set. Preferably, graduations or other markings are provided on the hub housing 42 so that an established inclination setting can be noted and relied upon to set up the device for subsequent use. Any conventional fastening means, such as the clamping handle with ball knobs illustrated in the drawings, that is commonly used and well known to one skilled in the art may be employed to adjustably secure the hub housing 42 to the stand 43 . [0032] Now referring to FIGS. 4 a and 4 b, there is shown the rotation control assembly 40 . A center brace 44 is positioned in the middle and affixed to the interior wall of the hub housing 42 (shown in FIG. 2 ). The hub 41 is free to rotate relative to the center brace 44 . Clockwise and counterclockwise dampening means 45 are provided on either side of the center brace 44 to limit the range of rotation of the swing plane guide 50 . Each dampening means 45 consists of a torsion spring 46 fitted over the hub 41 , an anchor pin 47 affixed to the center brace 44 , and a pickup pin 48 affixed to a disc 49 which is attached to and rotates in step with the hub 41 . The placement of the pickup pin 48 relative to the anchor pin 47 is dependent on design specifications such as at what point of the swing the dampening means should be actuated and the leg angle of the torsion spring. Generally, the pickup pin 48 is positioned where it will start to engage with the leg of the torsion spring 46 when the swing plane guide 50 has rotated more than 180 degrees from its at-rest position. The counterclockwise dampening means 45 is actuated when the swing plane guide 50 has rotated counterclockwise more than 180 degrees; likewise, the clockwise dampening means 45 is actuated when the swing plane guide 50 has rotated clockwise more than 180 degrees. The pickup pin 48 engages with the leg of the torsion spring 46 only in one direction, either clockwise or counterclockwise. For instance, the pickup pin 48 of the counterclockwise dampening means 45 can only engage with the torsion spring 46 when the hub 41 is rotating counterclockwise. It simply pushes against the torsion spring 46 , which rotates freely, when the hub 41 is rotating clockwise. [0033] Referring to FIGS. 1 and 2 , the swing plane guide 50 is connected by swing arm 52 , preferably removably, to the front side (relative to the user) of the hub 41 for constraining and controlling the swing path of the simulated golf club 70 . A counterweight 51 is provided and connected to the hub 41 opposite the swing plane guide 50 although it can be on an extension of swing arm 52 . The swing arm 52 of the swing plane guide 50 is a rigid tube or rod which is largely concave relative to the user's position on the base member 20 so that it will clear the user's head when the swing is approaching the top of the backswing or the end of the follow-through. The swing arm 52 consists of upper and lower portions adjustably attached such that the radius of the swing arc can be altered to suit the user's stature. The length adjustment means 52 e may be any conventional means suitable for the type of material used to fabricate the swing arm 52 . At its lower end the swing arm 52 forks into two portions, an upper fork 52 b and a lower fork 52 a terminating at ends 52 d and 52 c respectively. The forked configuration is for the purpose of firmly connecting the radius adjustment assembly 53 to the swing arm 52 . [0034] Referring to FIGS. 2 , 5 a and 5 b, the radius adjustment assembly 53 has a support member 54 , a linear motion assembly 55 and a universal pivoting assembly 56 . The support member 54 has a first end 54 a and a second end 54 b which are attached respectively to the terminating ends 52 c and 52 d of the lower forked portion of the swing arm 52 . The support member 54 can made from a straight section of tube with the underside cut out or a section of rod or any other configuration that can be employed to attach the linear motion assembly 55 to the swing arm 52 as shown by extension line C intersecting axis A at a right angle D. The upper fork 52 b of the swing arm 52 becomes substantially straight as it joins the radius adjustment guide 53 at 52 d. The linear motion assembly 55 (described below) is affixed to the support member 54 for connecting the simulated golf club 70 to the swing plane guide 50 and for providing the radius adjustment during the swing. An optional part of the linear motion assembly 55 , referred to as the swing plane varying assembly will be described below. The universal pivoting assembly 56 is attached to the linear motion assembly 55 . [0035] As illustrated in FIGS. 5 a and 5 b, the linear motion assembly 55 consists of a first part and a second part. The first part referred to as the swing plane varying assembly is contained inside or affixed to the straight portion of the upper fork 52 b of the swing arm 52 . It comprises a rod 57 slidably held in position by a front brace 58 and a back brace 59 affixed to the interior wall or the surface of the upper fork 52 b of the swing arm 52 , and a compression spring 61 fitted over the rod 57 between the front brace 58 and an actuator 62 affixed to the rod 57 . The second part of the linear motion assembly 55 comprises a track 63 positioned within or otherwise mounted on the support member 54 , a carriage 64 slidably disposed on the track 63 . It will be understood that any linear motion guide assembly that is generally known in the industry may be employed. The end (referred to as the upper end) of the track 63 proximate the upper end 52 d of the swing arm 52 is connected to the rod 57 and the other end (referred to as the lower end) is affixed to an end 54 a of the support member 54 by pivot means 65 such as a pintle. The universal pivoting assembly 56 is attached to the carriage 64 for holding the simulated or training golf club 70 . Hence, for a user whose downswing starts on a slightly flatter plane, when force is exerted on the track 63 , it causes the rod 57 to slide generally axially compressing the compression spring 61 between the actuator 62 and the front brace 58 . The center opening in the front brace 58 is slightly enlarged to accommodate the slight change in the angle between the front brace 58 and the back brace 59 during use. Preferably, an energy-absorbing element such as a spring 66 is added between the actuator 62 and the back brace 59 to absorb the return force. The universal pivoting assembly 56 is a universal joint consisting of a Y-shaped yoke 67 and a collar 68 held on a transverse bar through which the simulated or training golf club 70 is slidably fitted. The yoke 67 rotates around an axis perpendicular to the track 63 and the collar 68 rotates around an axis parallel to the track 63 ; consequently, the simulated golf club 70 can freely pivot relative to the linear motion assembly 55 . Preferably, energy-absorbing elements such as rubber, sponge foam or springs are added at either end of the track 63 to absorb and dissipate the impact force from the carriage 64 moving back and forth along the track 63 when the device is in operation. In an alternate embodiment, if the objective is to train the user to swing on plane through the entire swing and therefore disallow the downswing to initiate on a slightly flatter plane, the first part, the swing plane varying assembly, may be omitted and the linear motion assembly 55 consists of only the second part as defined above with the track 63 fixedly attached to the swing arm 52 at both the upper and lower ends 52 d and 52 c. [0036] Referring now to FIGS. 1 and 2 , the simulated golf club 70 is a club shaft 71 with a handle 72 at one end and a stopper 73 removably attached to the other end to imitate a golf club. For training, a user can also use his/her own golf club or otherwise a real golf club. Therefore either the simulated or an actual golf club is referred to as a training golf club for purposes of use with the present invention. For the simulated golf club, to assemble it, the club shaft 71 is threaded through the collar 68 of the universal pivoting assembly 56 and then the stopper 73 is attached. A spring element preferably is provided and placed between the stopper 73 and the collar 68 to cushion the impact between the two parts during operation. In an alternate embodiment of the present invention, the club shaft 71 has a handle 72 at one end and the other end terminates at and is removably affixed to the collar 68 of the universal pivoting assembly 56 . The simulated golf club 70 thus can still freely pivot relative the linear motion assembly 55 . [0037] In the preferred embodiment of the present invention, a resistance mechanism 80 is included to provide variable-force resistance for exercising the muscle groups which should be activated on the downswing and are most effective in transferring maximum power to a golf ball. Referring to FIGS. 1 , 2 , 4 a and 4 b, the resistance mechanism 80 comprises a freewheel 81 removably mounted on the back side of the hub 41 , and a flywheel 82 , which is a weighted disk, removably mounted on the freewheel 81 . The attachment means for mounting the freewheel 81 on the hub 41 and the flywheel 82 on the freewheel 81 may include cooperative projections and slots, i.e., keys and keyways, or matching threads or splines. In mechanical or automotive engineering, a freewheel design typically has spring-loaded rollers inside a driven cylinder. When the driveshaft rotates in one direction, projections on the driveshaft lock with the rollers making the cylinder rotate in unison. When the driveshaft rotates slower or in the other direction, the rollers just slip and the cylinder disengages from the driveshaft. Thus, employing a freewheel design allows the resistance mechanism 80 to provide resistance in one direction only. The freewheel 81 can be flipped over for use by a left-handed golfer; differently weighted flywheels may be provided to suit golfers desiring different levels of resistance force. Alternatively, if constant-force resistance is desired for overall muscle strength training, the freewheel 81 can be replaced with a cylinder that is in continuous engagement with the hub 41 and provides constant-force resistance. [0038] In use, the golf swing plane training device 10 is set up at a suitable location and the rotation control assembly 40 is adjusted to a desired angle of inclination B ( FIG. 2 ), either from a previously noted setting or for initiating trials to identify appropriate settings for subsequent use. As the angle of the swing plane naturally changes depending on factors such as the golf club used and the lie, it is advisable for the user to practice with different settings so as to “groove” his/her swing with the swing plane at different angles. Depending on the goal of the practice session, the resistance mechanism 80 may be mounted with a flywheel 82 of the desired weight, or omitted entirely. Referring to FIGS. 3 a - 3 d, which show the backswing, as the user takes the simulated golf club 70 back, the swing plane guide 50 constrains the club shaft 71 to stay on the swing plane, but allows it to extend through the collar 68 to follow an elliptical arc. As the simulated golf club 70 approaches the top of the swing, the swing arc flattens further. The radius adjustment assembly 55 allows the club shaft 71 , connected to the carriage 64 via the universal pivoting assembly 56 to slide lower along the track 63 while still staying on plane. If the user makes a full swing, the counterclockwise dampening means 45 (for a right-handed user) is actuated to dampen the momentum and slow down the simulated golf club 70 to prevent it from going much past horizontal. Now referring to FIGS. 5 c and 5 d (oriented in the drawings for the top of the backswing or the beginning of the downswing), if the user's downswing naturally follows a slightly flatter swing plane, the initiation of the downswing pulls on the track 63 which, in turn, causes the rod 57 to extend axially and the actuator 62 to compress the compression spring 61 against the front brace 58 . As the compressive force abates during the downswing and the compression spring 61 returns to its original form, in the middle of the downswing, the rod 57 retracts and the simulated golf club 70 is guided back to the original swing plane before it reaches the impact zone. Therefore, the swing plane guide 50 constrains the club shaft 71 to move on the same or a slightly flatter plane on the downswing, but restricts the club shaft 71 from moving down on a steeper plane, i.e., the “outside-in” or “over-the-top” move that many recreational golfers make. The clockwise dampening means 45 is actuated to slow down the club as the swing reaches the end of the follow-through. [0039] To conclude, with respect to the above description, it is to be understood that the optimal dimensional specifications for the parts of the invention, including variations in number, size, shape, form, placement, material and the method of fabrication and assembly, are deemed readily apparent to persons skilled in the art upon a reading of the foregoing description, and all equivalent specifications to those illustrated in the drawings and detailed in the description are intended to be encompassed by the present invention. [0040] Further, it will be obvious to those skilled in the art that various modifications and revisions can be made to the embodiment shown herein without departing from the spirit and essential characteristics of the invention. It is therefore intended by the appended claims to cover any and all such modifications and revisions within the scope of the present invention.

A golf swing plane training device is disclosed that helps the user develop a correct swing plane as well as exercise the muscle groups most effective in imparting maximum power to a golf ball. The device is portable and comprises a rotating swing plane guide, one end pivotably connected to a club shaft, for controlling the swing arc of the club shaft when swung by the user to ingrain the feel of swinging on plane. The other end of the rotating swing plane guide is connected to a rotation control assembly mounted on a vertically adjustable support frame. A resistance source is connected to the hub of the rotation control assembly.

RELATED APPLICATIONS This application is a continuation-in-part application of application Ser. No. 09/009,659 of same title, filed Jan. 20, 1998. FIELD OF THE INVENTION The present invention relates to synthetic, branched chain, oil soluble, fatty acid esters which, when preferably partially neutralized in situ, is revealed as a new water-in-oil emulsfier. Formulations are presented which demonstrate a method for using the disclosed emulsifier to prepare stable water-in-oil emulsions of varying polarity and viscosity for use in a variety of dermatological applications, and/or wherever this type of emulsion may be useful. BACKGROUND OF THE INVENTION Since 1957 for the inventor, and much earlier for the art, the use of a beeswax-borax system to prepare a water-in-oil emulsion has been available in the art. This is a classical method for preparing water-in-oil emulsions, i.e, which generally comprise at least about 2/3 by weight of an oil phase and no more than about 1/3 by weight of a water phase. Typically, prior art emulsions of this type comprise about 9-10% by weight of beeswax in the oil phase and about 1% Borax NF in the water phase. The oils used to produce the oil phase include mineral oil and petrolatum and viscosity was built with paraffin and other waxes such ozokerite in minor amounts. According to the Merck index, beeswax is comprised of approximately 22-25% by weight of a 36 carbon acid. In addition, beeswax generally comprises approximately 25% by weight C 35 -C 36 alkanes and approximately 50% by weight of C 35 -C 36 esters. Using beeswax, in the traditional water-in-oil emulsion, the acid and borax together form a "soap" emulsifier in situ which facilitates formation of the water-in-oil emulsion. Although the system functions reasonably well, problems emerge as beeswax may vary in componentry from batch to batch and produce quality control problems. In addition, compositions which utilize beeswax often require strenuous mixing or homogenization to facilitate the production of a stable final formulation. Since 1982, the present inventor worked with 12-hydroxystearic acid to prepare solid di-fatty esters such as 12-stearoyl, stearyl and stearate. One of the first products synthesized in this series was a "tri fatty" solid emollient which is still sold under the tradename Hetester SSS. After almost 40 years of research, the present inventor tried to make a C 36 then a C 40 acid to mimic beeswax in the latter's ability to form water-in-oil emulsion compositions, but without the other "solids" present in beeswax, which he identified as possibly being responsible for certain non-optimal characteristics of these compositions. In addition, it was surmised that the synthesis of a synthetic beeswax fatty acid would be more controllable and therefore would result in more accurate quality control ("QC") during processing. OBJECTS OF THE INVENTION It is an object of the invention to provide 12-hydroxy stearic acid esters which function as emulsifiers to provide storage stable water-in-oil emulsions. It is an additional object of the invention to provide a method of making water-in-oil emulsions which are easy to formulate, are self-homogenizing and provide for accurate quality control. It is yet another object of the invention to provide water-in-oil emulsions which can be used to readily manufacture personal care products including cosmetic products such as lipsticks as well as a myriad of types of creams and lotions. It is still another object of the invention to provide water-in-oil emulsion compositions which exhibit significantly greater storage stability than those compositions of the prior art which include beeswax. These and other objects of the invention may be readily gleaned from the detailed description of the invention which follows. BRIEF DESCRIPTION OF THE PRESENT INVENTION The present invention relates to 12-hydroxystearic acid ester compounds of the structure: ##STR1## Where R is a linear or branch chained saturated or unsaturated C 6 -C 35 hydrocarbon group, more preferably a C 11 -C 23 hydrocarbon group. Most preferably, R is a C 21 -H 43 group (such that the emulsifier is the behenoyl ester of 1 2-hydroxystearic acid or behenoyl stearic acid, "BSA"). The present 12-hydroxystearic acid esters may be utilized to produce water-in-oil emulsions for use as personal care products, such as creams and lotions, including pigmented formulations and as substitutes for beeswax in water-in-oil emulsions. The present compounds find particular use in emulsions, such as pigmented emulsions or moisturizing emulsions, among numerous others. These compounds provide excellent emulsification and, quite unexpectedly, are also excellent emollients. In many instances, the present compounds also plasticize the oils which are present in water-in-oil emulsion compositions to leave a dry, waxy feel rather than a predominantly oily, greasy feel. This unique feel is an unexpectedly favorable characteristic of water-in-oil emulsions according to the present invention. Compositions based upon the present compounds exhibit consistent manufacture, thus obviating the quality control problems which occur when beeswax is used in traditional formulations. In addition, many of the compositions which are produced using the present compound are self-homogenizing, i.e., they are relatively easy to mix into a consistent formulation, without reliance on high speed sheer forces or other strenuous methods of mixing. Moreover, the water-in-oil emulsions according to the present invention exhibit unexpectedly favorable storage stability even at high temperatures (50° C.). This is a particularly advantageous feature compared to water-in-oil emulsions which have shown storage instability (i.e., separation into phases upon storage) leading to limited commercial application. Emulsion compositions according to the present invention remain significantly more stable without separation at high temperatures (50° C.) compared to prior art compositions which utilize beeswax in the formulation. Water-in-oil emulsion compositions according to the present invention comprise an oil phase and a water phase, with the oil phase generally ranging from about 10% to about 90% by weight of the water-in-oil emulsion composition and the water phase ranging from about 10% to about 90% by weight of the water-in-oil emulsion composition. More preferably, the oil phase in the composition ranges from about 25% to about 80% by weight of said composition, even more preferably about 40% to about 75% by weight of said composition, even more preferably about 50-60% to about 75% by weight, still more preferably about 65 to 70% by weight, and most preferably about 66-67% (about 2/3) by weight of said composition. The water phase (such phase including the borax-containing compound or related compound which reacts with the 12-hydroxystearic acid ester in the oil phase to produce an oil soluble salt upon mixing the water and oil phases) in the water-in-oil emulsion compositions according to the present invention comprises about 10% to about 90% by weight, preferably about 20% to about 75% by weight, more preferably about 25 to about 60% by weight, even more preferably, about 25% to about 40-50% by weight, still more preferably about 30 to about 35% by weight, most preferably about 33-34% (about 1/3) by weight of the emulsion composition. In the present invention, the oil phase comprises an oil in a major amount (i.e., greater than about 50% by weight, more preferably at least about 70% and even more preferably about 75 to about 99.75% by weight of the oil phase) and as a minor component a hydroxystearic acid ester compound according to the chemical structure: ##STR2## Where R is a linear or branch chained saturated or unsaturated C 6 -C 35 more preferably, a C 11 -C 24 hydrocarbon group, even more preferably, a C 21 H 43 group, as a minor component (i.e., less than about 50% by weight). Thus, in the present invention the hydroxystearic acid ester preferably comprises about 0.25% to about 30% by weight of the oil phase, more preferably, about 0.5% to about 20% by weight of the oil phase, even more preferably about 1.0% to about 10% by weight of the oil phase, and even more preferably about 1% to about 7.5% by weight of the oil phase. The amount of oil in the oil phase preferably ranges from about 70% to about 99.75% by weight, more preferably, about 80% to about 99.5% by weight, even more preferably about 92.5% to about 99% by weight. It is noted here that the amount of the hydroxystearic acid ester compound and oil to be included within the oil phase will vary depending upon the amount of water to be included in the water-in-oil emulsion composition. As the amount of water increases in the emulsion composition, the amount of the hydroxystearic acid ester which is included in the emulsion composition also generally increases and the amount of oil decreases, as does the inversion temperature. In addition to water, the water phase may also include an amount of a "neutralizing agent or compound" effective to produce an emulsion when the water phase and oil phases are combined. Examples of such compounds include, for example, boron-containing compounds such as sodium tetraborate decahydrate (Borax NF), sodium tetraborate tetrahydrate, Ca(OH) 2 , Mg(OH) 2 , Al(OH) 3 , disodium monohydrogen phosphate or dipotassium monohydrogen phosphate (i.e., Na 2 HPO 4 or K 2 HPO 4 ), trisodium phsophate or tripotassium phosphate (Na 3 PO 4 or K 3 PO 4 ), NaHCO 3 , KHCO 3 , Na 2 CO 3 , K 2 CO 3 , NaOH and KOH (preferably, buffered NaOH and KOH) and fatty amine compounds (i.e., primary, secondary and tertiary amine compounds containing at least one C 10 to C 22 alkyl, alkene or substituted alkyl or alkene group). Emulsion compositions according to the present invention may also include optional additives, for example, fragrances, preservatives, anti-oxidants, vitamins, pigments, conditioning agents, among numerous other standard cosmetic additives. These additives may be included in emulsion compositions according to the present invention in amounts up to about 25% by weight, preferably, in amounts ranging from about 0.01% to about 10% by weight, most preferably less than about 5% by weight within this range. DETAILED DESCRIPTION OF THE INVENTION The terms "emulsion" and "water-in-oil emulsion" are used synonymously throughout the specification to describe compositions according to the present invention. An "emulsion" according to the present invention is a cream or lotion which is generally formed by the suspension of a very finely divided liquid, in this case water, in another liquid, in this case, an oil. In the present invention, an emulsion is formed when the water phase is compatibilized in the oil phase, such that the water phase becomes "hidden" within the oil phase. While not being limited by way of theory, it is believed that in the water-in-oil emulsion compositions according to the present invention, the oil phase produces a liposome- or encapsulation-like structure or a related structure surrounding water and/or the water phase, with the reaction product of the 12-hydroxy stearic acid ester and neutralizing compound serving to enhance the formation of the liposome-like structure and consequently, the emulsion composition. The term emulsion is used to distinguish the present compositions from compositions which contain at least two distinct phases, i.e., an oil phase and a water phase. The term "hydrocarbon" is used throughout the specification to describe R groups according to the present invention. R may be a linear or branch chained saturated or unsaturated C 6 -C 35 hydrocarbon group, more preferably, a C 11 -C 24 hydrocarbon group, even more preferably, a C 21 -H 43 group. The term hydrocarbon embraces, but is not limited to, for example, alkyl, alkene groups (including those groups containg more than one unsaturated double bond), alkyne groups, aryl groups, aralkyl groups and related groups which are comprised of carbon and hydrogen atoms. Groups which may be found on fatty amines according to the present invention also may be described as hydrocarbons, although the number of carbon atoms which are found in hydrocarbon groups in the fatty amine according to the present invention falls within a more narrow range than do the hydrocarbon groups which may be used as R groups in stearic acid esters or emulsifiers according to the present invention. The term "inversion temperature" is used throughout the specification to describe a temperature at which emulsion formation occurs with stability. Emulsion compositions according to the present invention generally have inversion temperatures of at least about 40° C., more preferably about 50° C. or higher. The term "oil" is used throughout the specification to describe any of various lubricious, hydrophobic and combustible substances obtained from animal, vegetable and mineral matter. Oils for use in the present invention may include petroleum-based oil derivatives such as purified petrolatum and mineral oil. Petroleum-derived oils include aliphatic or wax-based oils, aromatic or asphalt-based oils and mixed base oils and may include relatively polar and non-polar oils. "Non-polar" oils are generally oils such as petrolatum or mineral oil or its derivatives which are hydrocarbons and are more hydrophobic and lipophilic compared to synthetic oils, such as esters, which may be referred to as "polar" oils. It is understood that within the class of oils, that the use of the terms "non-polar" and "polar" are relative within this very hydrophobic and lipophilic class, and all of the oils tend to be much more hydrophobic and lipophilic than the water phase which is used in the present invention. In addition to the above-described oils, certain essential oils derived from plants such as volatile liquids derived from flowers, stems and leaves and other parts of the plant which may include terpenoids and other natural products including triglycerides may also be considered oils for purposes of the present invention. Petrolatum (mineral fat, petroleum jelly or mineral jelly) and mineral oil products for use in the present invention may be obtained from a variety of suppliers. These products may range widely in viscosity and other physical and chemical characteristics such as molecular weight and purity. Preferred petrolatum and mineral oil for use in the present invention are those which exhibit significant utility in cosmetic and pharmacuetical products. Cosmetic grade oils are preferred oils for use in the present invention. Additional oils for use in the present invention may include, for example, mono-, di- and tri-glycerides which may be natural or synthetic (derived from esterification of glycerol and at least one organic acid, saturated or unsaturated, such as for example, such as butyric, caproic, palmitic, stearic, oleic, linoleic or linolenic acids, among numerous others, preferably a fatty organic acid, comprising between 8 and 26 carbon atoms). Glyceride esters for use in the present invention include vegetable oils derived chiefly from seeds or nuts and include drying oils, for example, linseed, iticica and tung, among others; semi-drying oils, for example, soybean, sunflower, safflower and cottonseed oil; non-drying oils, for example castor and coconut oil; and other oils, such as those used in soap, for example palm oil. Hydrogenated vegetable oils also may be used in the present invention. Animal oils are also contemplated for use as glyceride esters and include, for example, fats such as tallow, lard and stearin and liquid fats, such as fish oils, fish-liver oils and other animal oils, including sperm oil, among numerous others. In addition, a number of other oils may be used, including C 12 to C 30 (or higher) fatty esters (other than the glyceride esters, which are described above) or any other acceptable cosmetic emollient. Preferred oils for use in the present invention include petrolatum, mineral oil or mixtures of petrolatum and mineral oil where the amount of petrolatum to mineral oil (on a weight/weight basis) ranges from about 1:20 to about 10:1, preferably about 1:5 to about 5:1, more preferably about 1:3 to about 1:1, depending upon the end use of the emulsion composition. The inclusion of petrolatum and/or mineral oil and/or the ratio of petrolatum to mineral oil in the present compositions will greatly influence the final viscosity of the water-in-oil compositions according to the present invention. The term "storage stability" is used throughout the specification to describe an unexpected characteristic of emulsion compositions according to the present invention which relates to the fact that the present emulsions are generally storage stable at 50° C. for a period of at least about three months, and often longer than six months, a year or even longer. This is a particularly advantageous feature of emulsion compositions according to the present invention in comparison to prior art compositions, especially those which utilize beeswax to form the emulsion. Those prior art compositions tend to separate into at least two separate phases, generally a water phase and an oil phase within a relatively short period at a temperature at or above about 50° C. The term "carboxylic acid reactive neutralizing agent or compound" or "neutralizing compound" is used throughout the specification to describe a compound which is reactive with the carboxylic acid group of the stearic acid ester to produce a salt or complex of the carboxylic acid in an amount effective to produce a stable emulsion when the water phase and oil phases are combined. In the present invention, the neutralizing agent or compound reacts or complexes with the carboxylic acid moiety of the 12-hydroxy stearic acid ester compound. A neutralizing compound for use in the present invention may be any alkaline compound which forms a hydrophobic/lipophilic soap (salt) with the 12-hydroxy stearic acid ester compound. In certain embodiments according to the present invention, preferred neutralizing compounds include any alkaline salt whose 5% aqueous solution gives a pH ranging from about 8 to about 12, preferably about 9-11. Preferred alkaline salts include, for example, Na 2 HPO 4 or K 2 HPO 4 Na 3 PO 4 , K 3 PO 4 , NaHCO 3 , KHCO 3 , Na 2 CO 3 , K 2 CO 3 , and mixtures thereof, among others. In the present invention, the amount of neutralizing compound to 12-hydroxy stearic acid ester compound used in the final emulsion composition ranges from about 1 part (weight/weight) to 10 to about 2 parts to 1, more preferably about 1:4 to about 1:1, more preferably about 1:2. The amount of neutralizing compound to 12-hydroxy stearic acid ester compound used in the present compositions is not necessarily a stoichiometric amount. It is noted that this amount should serve as a guide, but not to limit, the understanding as to the amount of neutralizing compound to be used in the present invention. Examples of preferred neutralizing compounds include, for example, boron-containing compounds such as sodium tetraborate decahydrate (Borax NF), sodium tetraborate tetrahydrate, tetrahydroxy boron, boron monoxide (which converts to tetrahydroxy boron on reactions with water), Ca(OH) 2 , Mg(OH) 2 , Al(OH) 2 , Na 2 HPO 4 or K 2 HPO 4 Na 3 PO 4 , K 3 PO 4 , NaHCO 3 , KHCO 3 , Na 2 CO 3 , K 2 CO 3 , NaOH, KOH and fatty amine compounds (i.e., primary, secondary and tertiary amine compounds containing at least one C 10 to C 22 alkyl group) and mixtures thereof, especially mixtures of the previously described phosphate and carbonate salts. Preferred neutralizing compounds which are used in the present invention include, for example, sodium tetraborate decahydrate (Borax NF) and sodium tetraborate tetrahydrate, with sodium tetraborate decahydrate (Borax NF) being the preferred compatibilizing agent for use in the present invention. The term "self-emulsifier" or "self-emulsification" is used to describe compounds according to the present invention which are the reaction products of a 12-hydroxy stearic acid ester compound and a neutralizing compound according to the present invention and may be used to create emulsion compositions according to the present invention by simple mixing, i.e., without relying on shear forces or high speed mixing action. These emulsifiers may be created in situ by mixing the 12-hydroxy stearic acid ester with the neutralizng compound during formation of the emulsion, or alternatively, may be prepared separately, by neutralizing the 12-hydroxy stearic acid ester with the neutralizing compound and then adding the pre-formed emulsifier to other components to form the emulsion composition. The term "secondary emulsifier" or "helper emulsifer" is used throughout the specification to describe compounds which are added to the emulsifier compositions according to the present invention to provide a more stable and in some embodiments consistent emulsion composition. Secondary or helper emulsifiers may be particularly advantageous when formulating emulsions compositions which utilize one or more salts such as phosphate salts or carbonate salts to neutralize the srtearic acid ester. Emulsifiers as used generally are considered surfactants which exhibit good surface activity and produce a low interfacial tension in the system in which it is used. Secondary emulsifiers preferably used in the present invention exhibit a tendency to migrate to the interface, rather than remain dissolved in either one of the water or emollient oil phase. Mixtures of secondary emulsifiers actually may be preferred in certain embodiments, where the need is to provide better interaction between the oil and water phases. Secondary emulsifiers have been advantageously used in the present invention where the neutralizing agent is or contains at least one phosphate or carbonate salt, or where the oil is a synthetic ester or more polar oil. One of ordinary skill in the art may readily determine the type of emulsifier or emulsifying system (group of emulsifiers) which may be used in the water-in-oil emulsions according to the present invention. A secondary emulsifier is used in the present invention in an amount effective to aid or promote emulsification of the water phase and oil phase ("emulsification effective amount"). As a general rule, the amount of secondary emulsifer which is included in compositions according to the present invention ranges from about 0.01% to about 10% by weight, more preferably about 0.1% to about 5.0% by weight of the final emulsion composition. In emulsion compositions according to the present invention, where secondary emulsifiers are optionally included, the weight ratio of 12-hydroxystearic acid esters to secondary emulsifier ranges from about 20:1 to about 1:20, more preferably about 10:1 to about 1:1. Exemplary secondary emulsifiers for use in the present invention may be any cosmetically acceptable oil soluble non-ionic or anionic (and in rare instances quaternary or amphoteric) surfactant which has a hydrophilic group ("tail") at one end of the molecule, of which polyethylene glycol 1500 dihydroxystearate (Arlacel P135®, available from ICI Americas, Inc) and diethanolamine cetyl phosphate (Amphisol®, available from Givaudin-Roure, division of Roche, Inc.) are particularly preferred, although a large number of other secondary emulsifiers may be used in the present invention. One of ordinary skill will understand to include one or more secondary emulsifiers in emulsion compositions according to the present invention in order to facilitate and enhance interaction of the water and oil phases. In addition to 12-hydroxy stearic acid ester compounds, an oil, water and neutralizng compound, the emulsion compositions may also comprise, in amounts totalling up to about 25% by weight of the total emulsion composition, preferably comprising about 0.001% to about 10% by weight, even more preferably no more than about 5% by weight within this range, of one or more optional additive selected from one or more secondary emulsifier, fragrances, preservatives, anti-oxidants, vitamins, pigments, conditioning agents, among numerous other standard cosmetic additives. 12-Hydroxy stearic acid ester compounds according to the present invention are generally made by reacting 12-hydroxy stearic acid with another carboxylic acid (depending upon the length and degree of unsaturation of the carboxylic acid which is reacted to form the ester group at the 12 hydroxyl position) in the presence of an effective amount of a catalyst (the amount can range from 0.005% to 1% or more by weight of the 12-hydroxy stearic acid and other carboxylic acid reactant used) such as dibutyl tin oxide or tin oxalate, among numerous others. In a preferred method, stoichiometric amounts (i.e., a 1:1 molar ratio) of the reactants are combined with the catalyst in a reaction chamber which will allow ample heat to be added to the mixture (the temperature of the reaction may vary depending upon the rate of reaction desired, but will preferably be above about 200° C.) and water to be removed (as the esterification reaction proceeds). The reaction mixture is heated until a desired saponification value is obtained evidencing completeness of the reaction. Upon cooling the reaction mixture, the stearic acid ester compound is readily separated from impurities, by extraction, fractionation (under reduced pressure), simple crystrallization or related techniques which are all well known in the art. Preferably, the stearic acid ester is obtained in quantitative or near quantitative yields. Emulsion compositions according to the present invention may be made by mixing the individual components in any order at elevated temperature, but are preferably made by first preparing the oil phase and water phase at elevated temperature (preferably, above about 70-75° C., more preferably above about 85° C.) separately, then combining the oil phase with the water phase also at an elevated temperature (preferably, by adding the water phase to the oil phase) such that the oil phase remains soluble within itself during mixing. Generally, the temperature at which mixing is effected is preferably at least about 50° C., more preferably at least about 65 to 75° C., even more preferably at least about 75 to 85° C., and most preferably at least about 85° C. These are temperatures which are generally effective to allow the oil phase to remain soluble within itself (at a temperature wherein the oil phase remains clear and in a solution) during mixing. After mixing for at least about 10-15 minutes, more preferably at least 30 minutes or more (depending upon batch size) at elevated temperatures, the mixture is then cooled before use and/or packaging. Mixing is generally performed in a simple propeller mixer with vortex formation without the application of high shear force. Although one could use higher mixing speeds, the self-emulsifiers which are used make mixing the compositions relatively easy. All components may be mixed together in a one pot preparation, or one or more components (such as the oil phase, water phase or emulsifier) may be prepared separately and then combined. In preferred embodiments, after the separate water and oil phases are prepared, the water phase is added to the oil phase and the combined phases are mixed thoroughly for maximum result. It is noted that the preferred method for making the present composition comprises first making the water and oil phases separately, preferably adding the water phase to the oil phase, followed by mixing the phases together, all at elevated temperature. Alternatively, it is possible to separately mix the individual components in a single pot preparation or prepare the complex of the stearic acid ester compound and the neutralizing compound before it is added to the oil and/or water phases. It is noted that the 12-behenoyl stearic acid (BSA, also known by the names 12-(behenoyloxy)stearic acid and 12-(decosanoyloxy)octadenaoic acid ) is more efficient at producing an emulsion with non-polar oils (such as mineral oil or petrolatum) or emollients than it is with polar oils (such as fatty esters, etc.) or emollients. In certain instances, when utilizing polar oils or emollients, either alone or in combination with a non-polar oil, at least one additional secondary or helper emulsifier may be advantageously added to produce a superior emulsion composition. In certain embodiments, therefore, the inclusion of a secondary emulsifer may be advantageously employed. Preferred secondary emulsifiers for inclusion in the present emulsion compositions include for example, polyethyleneglycol 1500 dihydroxystearate (Arlacel P135® m , available from ICI Americas, Inc.) and diethanolaminecetyl phosphate (Amphisol®, available from Givaudin-Roure), in amounts generally ranging from about 0.01% to about 10% (up to aobut 20% by weight of the final emulsion composition), more preferably about 0.1% to about 5%, by weight of the final emulsion composition. Emulsion compositions according to the present invention have inversion temperatures of at least about 40-45° C., preferably at least about 50° C., more preferably at least about 60° C. or higher. Inversion temperatures of at least about 65 ° C. may be particularly preferred. The higher the inversion temperature of an emulsion composition according to the present invention, generally, the more stable is the emulsion composition. Having generally described the invention, reference is now made to the following examples which are intended to illustrate preferred embodiments and comparisons but which are not to be construed as limiting to the scope of this invention as is more broadly set forth above and in the appended claims. EXAMPLES Example I Synthesis of 12-Behenoyl Hydroxystearic Acid (BSA) Materials 1 mole Behenic acid 1 mole 12-Hydroxy Stearic acid 0.1% w/w Dibutyl Tin Oxide (Based upon total weight of reactants). Procedure In a glass vessel, equipped with proper mixing and a water trap to collect water, combine all ingredients. Mix and heat at 200° C. until desired saponification value, hydroxyl value and acid value are achieved. ______________________________________Typical Assay for BSAsap value = 161.5acid value 104.5hydroxyl value = 7.5color (melted) = gardner 2+melting point = 68° C.______________________________________ BSA is the common cosmetic label name. BSA also goes by the names 12-(behenoyloxy)stearic acid and 12-(decosanoyloxy)octadenaoic acid. Example II Water-in-Oil Flowing Lotion Based Upon Non-Polar Oils The following components were combined in two separate phases, phase A, the oil phase and phase B, the water phase. After complete mixing of components to produce each sof the individual phases in the amounts as set forth below, the two phases are combined under elevated temperature (85° C.) and mixing to produce a flowing lotion. ______________________________________ Weight %______________________________________Phase A: "BSA" 2.3(heat to 85° C. White Petrolatum 10.0and mix) 53.2 neral oil 0.1Phase B: 33.3 ed 1.1 100.0% total______________________________________ The procedure used was as follows: Phase B was added to phase A @85° C.--the combined phases were mixed and cooled without aeration to 45-50° C.--package. Note: In the case of this emulsion, the "BSA" is the primary and only emulsifier used. The use of about a 5:1 ratio of mineral oil to petrolatum produced a free-flowing lotion. Kaydol- type of mineral oil obtained from Witco, Inc. Example III Water-in-Oil Cream Based upon Polar and Non-Polar Oils The same procedure which was followed for Example II was also followed here, except that phase C was added after phases A and B were thoroughly mixed. ______________________________________ Weight %______________________________________Phase A: "BSA" 2.30(heat to 85° C. DiBehenyl Fumarate (1) 8.00and mix) White Petrolatum 10.00 Mineral Oil (Kaydol) 33.45 Di-2-Ethyl Hexyl Fumarate (2) 10.00 DEA Cetyl Phosphate (amphisol) (3) 0.50 Propyl Paraben 0.10Phase B: Water, deionized 33.30(heat to 85° C.) Borax 1.10Phase C: Fumed SiO.sub.2 (cabosil) 1.25(add to emul- 100.0% totalsion at 75-80° C.)______________________________________ (1) obtained by reacting 2 moles behenic alcohol with 1 mole fumaric acid using standard ester manufacturing procedures (heated at 160-180° C. with 10% by weight of the reactants of a catalyst such as tin oxalate or dibutyl tin oxide) in standard manufacturing equipment until an appropriate SAP value is reached. (2) commercial as Bernel Ester 284 (Bernel Chemical Co., Englewood, New Jersey) (3) Amphisol available from HoffmannLaRoche, Nutley, New Jersey. Procedure Add B to A at 85° C. Mix without aeration. Cool and add C at 75-80° C.; continue to mix until homogeneous and cool to approximately 55° C. Package at 55° C. Note: the "BSA" from example 1 is the primary emulsifier, however, this emulsion uses 2 auxilliary emulsifiers with "BSA". They are amphisol and cabosil. The di-behenyl fumarate is a "thickener" in this composition. Example IV Synthetic Water-in-Oil Cream Based upon Polar Oils The same procedure which was followed for Example III was essentially also followed here, with minor variation. ______________________________________ Weight %______________________________________phase A: "BSA" 2.30(mix at Di Behenyl Fumarate (1) 8.0085-90° C.) Di-C.sub.12-15 Alkyl Fumarate (2) 10.00 Di-Decyl Tetra Decyl Fumarate (1) 28.45 (Octyl Dodecyl NeoPentanoate) ELEFAC I-205 15.00 DEA Cetyl Phosphate (Amphisol) (3) 0.50 Propyl Paraben 0.10phase B: Water, deionized 33.30(mix at Borax N.F. 1.1085-90° C.)phase C: Fumed SiO.sub.2 (cabosil) 1.25 total 100.0%______________________________________ (1) obtained as per example III; (2) commercial as Marrix SF (Bernel Chemical Co., Englewood, New Jersey; (3) HoffmannLaRoche Procedure Add B to A at 85° C. and mix without aeration. Continue mixing while slowly adding C. Mix and cool to 50° C. Package. Example V Comparison of Related Water-in-Oil Emulsion Compositions A number of compositions were made to determine the levels of stearic acid ester at which stability is affected. The influence of mineral oil and petrolatum on stability was also determined. The results appear in Table 1, below. The compositions were made following the general procedure set forth in Example II, above. Essentially, the components of the oil phase, the behenyl stearic acid ester (BSA), the mineral oil and where applicable, petrolatum were combined in a phase A at elevated temperature (phase A also contained 0.1% by weight of propyl paraben dissolved in phase A as a preservative). To this phase A was added phase B, which included water and the Borax NF, also at elevated temperature (approximately 85 ° C.). The inversion temperature was determined by establishing at which temperature emulsion formation occurred (mixture becomes smooth and shiny evidencing the absence of two phases). TABLE 1__________________________________________________________________________ InversionExample % BSA % Borax NF % Water % Mineral Oil % Petrolatum Temp. (° C.)__________________________________________________________________________1 2.3 1.1 33.3 40.0 23.3 >68° C.2 50.0 42.5 56-52°3 65.1 23.1 46-43°4 17 >68° C.__________________________________________________________________________ BSA-12-Behenoyl Stearic Acid All % are % by weight of the total emulsion composition. Inversion Temperaturetemperature at which stable emulsion occurs pH's of the compositions are approximately 8.4. Conclusion 1) As the percent by weight of BSA was increased, the amount of water which could be included within the composition and still form an emulsion increased. Likewise, as the amount of water incrases, the inversion temperature tends to decrase significantly. 2) The highest percent by weight of water which can be included in the emulsion compositions is approximately 75%. 3) The lowest percent by weight of water which can be included in the emulsion compositions is approximately 10%. Note- In example 2 on the chart of Table 1, all ingredients alternatively alternatively were mixed together initially at room temperature (20-25° C) in a single pot method. The mixture was heated and mixed to 85° C., then with mixing and cooling, we obtained the same inversion temperature (56-52° C.) obtained by forming the emulsion by mixing two phases together at elevated temperature. This approach represents an alternative embodiment of the method of making the emulsions according to the present invention. In large production batches, the inventor believes that the water phase and oil phase should be prepared separately, preferably at a temperaturem of about 85° C. and then the water phase should be added to the oil phase at the elevated temperature in order to increase the solution of any compounds which might be insoluble in one of the phases. Example VI Mineral Oil System The following components were combined in two separate phases, phase A, the oil phase and phase B, the water phase. After complete mixing of components to produce each of the individual phases in the amounts as set forth below (at 80° C., with mixing), the two phases are combined under elevated temperature (80° C.) and mixing to produce a flowing lotion. ______________________________________ Weight %______________________________________Phase A: "BSA" 5.0(heat to 80° C. (Kaydol) Mineral oil 42.5and mix) 0.1Phase B: 50.0 2.4 total0.0%______________________________________ The procedure used was as follows: Phase B was added to phase A @80° C.--the combined phases were mixed and cooled without aeration to 40° C.--package. Note: In the case of this emulsion which used the non-polar mineral oil, the "BSA" is the primary and only emulsifier used. Kaydol--type of mineral oil obtained from Witco, Inc. Example VII Petrolatum Cream The following components were combined in two separate phases, phase A, the oil phase and phase B, the water phase. After complete mixing of components to produce each of the individual phases in the amounts as set forth below (at 80° C., with mixing), the two phases are combined under elevated temperature (80° C.) and mixing to produce a flowing lotion. ______________________________________ Weight %______________________________________Phase A: "BSA" 4.5(heat to 80° C. Petrolatum USP 47.75and mix) 0.1Phase B: 45.50 d 2.10 total0%______________________________________ The procedure used was as follows: Phase B was added to phase A @80° C.--the combined phases were mixed and cooled without aeration to 40° C.--package. Note: In the case of this emulsion which used the non-polar mineral oil, the "BSA" is the primary and only emulsifier used. Example VIII Suntan Lotion-SPF 30 Waterproof The same procedure which was followed for earlier examples was essentially also followed here, with minor variation. ______________________________________ Weight %______________________________________phase A: "BSA" 4.0(mix at Di Behenyl Fumarate (1) 3.080° C.) Arlacel P135 ® 2.0 Capryl isostearate 21.6 Beantree ™ (2) ELEFAC I-205 (3) 10.0 Octyl Methoxy Cinnamate 7.5 Octyl Salicylate 5.0 Oxy Benzone 5.0 Propyl Paraben 0.1phase B: Water, deionized 40.0(mix at Borax N.F. 1.880° C.) total 100.0%______________________________________ (1) obtained as per example III; (2) commercial as Beantree from Bernel Chemical Co., , Englewood, New Jersey; (3) Bernel Chemical Co. Procedure Add B to A at 80° C. and mix without aeration. Cool to 40° C. Package. Example IX Lotion Base Using Phosphate Salt as Neutralizing Agent The same procedure which was followed for the earlier described examples was essentially also followed here, with minor variation. ______________________________________ Weight %______________________________________phase A: "BSA"(1) 5.0(mix at 80° C.) Arlacel P-135 5.0 Capryl Isostearate (2) 20.0 Dibehenyl fumarate (3) 3.0phase B: Water, deionized 61.9(mix at Disodium Acid Phosphate 5.080° C.) (Na.sub.2 HPO.sub.4)Phase C: Kathon CG (4) 0.1 total100.0%______________________________________ (1) obtained as per example III; (2) commercial as Beantree (Bernel Chemical Co., Englewood, New Jersey); (3) commercial as Marrix 222 ® (Bernel Chemical Co., Englewood, New Jersey); (4) Rohm & Haas. Procedure Add B to A at 80° C. and mix until uniform. Cool to 70° C. and add Phase C. Continue mix and cool to 35-40° C. Package. Example X Petrolatum Cream Base Using Carbonate Salt as Neutralizing Agent The same procedure which was followed for earlier examples was essentially also followed here, with minor variation. ______________________________________ Weight %______________________________________phase A: "BSA" 4.5(mix at 3.0 umarate (1)80° C.) Arlacel P-135 ® 2.0 0.1 44.3phase B: 44.1(mix at 1.080° C.) NaHCO.sub.3 1.0 total00.0%______________________________________ Procedure Add B to A at 80° C. and mix until uniform. Continue mix and cool to 40° C. Package. It is to be understood by those skilled in the art that the foregoing description and examples are illustrative of practicing the present invention, but are in no way limiting. Variations of the detail presented herein may be made without departing from the spirit and scope of the present invention as defined by the following claims.

The present invention relates to a synthetic, branched chain, oil soluble, fatty acid esters which, when preferably partially neutralized in situ, is revealed as a new water-in-oil emulsifier. Formulations are presented which demonstrate a method for using the disclosed emulsifier to prepare stable water-in-oil emulsions of varying polarity and viscosity for use in a variety of dermatological applications, and/or wherever emulsions according to the present invention may be used.

FIELD OF THE INVENTION This invention relates to burglar alarms for vending machines. BACKGROUND OF THE INVENTION One of the problems facing owners of vending machines is destruction of their coin operated machines by thieves, both professional and amateur. When one tries to break into a machine, the destruction of the machine is the only way to reach the coin compartment. This wanton destruction of expensive vending machines calls for a specialized burglar alarm. This invention is especially appropriate for use with newspaper vending racks. Most newspaper vending racks are formed of two parts. The top part includes a locked coin compartment which contains a coin receiving mechanism. Beneath the coin compartment is a newspaper compartment with a hinged door which is unlatched when the appropriate amount of money is deposited in the coin receiving mechanism. The vending racks are often anchored to their position by chains wrapped around sign posts or mail boxes. However, thieves often cut the chain anchoring the rack to its location. No burglar alarms presently address the specific problems of vending machines. Vending machines are usually tampered with by amateurs who attempt to break into the rack and fail, but in the process damage the vending machine. More experienced thieves may have the equipment to seize an entire vending machine and remove it to a remote location before breaking into the coin compartment. An alarm system designed to deal with both modes of theft must take into consideration the customers who buy goods from the rack. Slamming the door must not set off the alarm. Getting money out of the coin return should not set the alarm off and some shaking of the rack should not set off the alarm. Therefore, it is an object of the present invention to provide an alarm device appropriate for use in vending machines. It is another object of the invention to provide an alarm system especially designed for newspaper vending machines which is easily installed in conventional newspaper vending racks. It is another object of the present invention to sound an alarm upon the occurrence of certain movements of a vending machine at the machine's location to help scare any thief and to alert the authorities to criminal activity. SUMMARY OF THE INVENTION The present invention provides a vending machine that is protected from theft or pilferage through an alarm device contained within the vending machine The vending machine has a housing which has a vending compartment for receiving and storing articles sold inside the vending compartment. The vending machine also has an enclosed locking coin compartment carried by the housing. The coin compartment has a coin receiving mechanism. The alarm device is contained in the coin compartment. When the vending machine is moved or tilted a predetermined amount for a predetermined period of time, an audible alarm within the alarm device sounds for so long as the box remains tilted. The alarm device is inexpensive, easy to install and difficult to disengage. More specifically, the alarm unit may comprise a tilt responsive switch having switch contacts which are activated in response to a predetermined amount of tilting from a level orientation, a delay circuit cooperating with the alarm so as to effect a sounding of the alarm a predetermined amount of time after tilting occurs. DESCRIPTION OF THE DRAWINGS The features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings in which: FIG. 1 shows a newspaper rack vending machine as it is normally positioned. FIG. 2 shows a cutaway rear view of the coin box with top and back sides removed and the alarm unit shown in different positions inside the coin box. FIG. 3 shows a cross section of the alarm unit box. FIG. 4 shows a schematic drawing of the circuitry of the alarm unit. Like characters refer to like elements throughout. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT While the invention will be described in connection with a preferred embodiment, it will be understood that Applicant does not intend to limit the invention to that embodiment. On the contrary, Applicant intends to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. Referring to FIG. 1, a vending machine, in this case a newspaper rack, is shown. The vending machine has a housing 10 formed by two parallel side walls 11, a rear wall 12 and a front wall 13. In the upper portion of the housing is provided a vending compartment 20 which receives and stores the articles vended by the machine. The vending compartment 20 has a hinged door 21 to provide access to the vended articles. The hinged door 21 has a latch 22 for maintaining the door in a normally latched condition. The housing carries an enclosed lockable coin compartment 23. The coin compartment 23 has a coin slot 24 connected to a coin receiving mechanism mounted inside. A latch mechanism 25 is also mounted within the coin compartment and is operable for unlatching the latch 22 of the hinged door 21 upon receipt of coins by the coin receiving mechanism. Referring now to FIG. 2, the coin compartment 23 is shown. A coin receiving mechanism 45 is mounted interiorly of the coin compartment 23. An alarm unit 50 in the form of a compact self-contained unit, is also mounted inside the coin compartment 23. Three positions for the mounting of the alarm unit 50 are shown. Others are also possible The only requirement for the mounting of the alarm unit 50 is that it is mounted level within the coin compartment. Thus for example, if the surface upon which the vending machine is positioned is not level, the alarm device will be nonetheless mounted in a level orientation. Device 55 is a mounting strip to assist in mounting the alarm unit and leveling it. The dimensions of the alarm unit 50 are small so as to fit inside the coin compartment of a conventional newspaper box without requiring modifications. Since the alarm unit 50 is within the locked coin compartment 23 and the coin compartment is difficult to break into, it will be quite difficult to disengage the alarm. In FIG. 3, a cross section of the alarm unit 50 is shown. The alarm unit 50 contains an audible alarm 60, such as a horn, which sounds when the vending machine is tilted or moved for more than a predetermined period of time. The alarm device is powered by two batteries 70 (typically, the batteries are nine volt). Since many vending machines may be in remote areas, the alarm should be quite loud. As specifically illustrated in FIG. 3, the alarm unit contains a control board 80 and, the circuitry of the alarm unit is located on the board 80. An on/off switch 100 is located on the outside of the alarm unit 50 and turns power on and off. A second switch 110 will indicate whether the battery charge is low and is preferably a push button switch which lights a lamp, such as a light emitting diode (LED), to indicate that both batteries are operational. Referring to FIG. 4, in operation when the switch 100 is closed the alarm device is energized by batteries 70. When the vending machine is tilted more than a predetermined amount a tilt switch S 2 closes. A variety of devices can be suitably employed as the tilt switch. In the preferred embodiment, a disk-like normally-open mercury switch is employed which is responsive to titling in any direction from a horizontal or level orientation. Preferably, the switch should be actuated (e.g. closed) in response to tilting in excess of 30 degrees, and most desirably the switch should be responsive to a tilting of 20 degrees or more. When tilt switch S 2 is closed, voltage is then supplied, to capacitor C1, here 5 volts. Capacitor C1 then begins to charge acting as a time delay for a period of time which may for example be 3 seconds. As capacitor C1 charges, the voltage at switching diodes D1 and D2 increases until it reaches a certain voltage, e.g. 0.6 volts. When switching diodes D1 and D2 reaches this desired voltage, they break down and send forward biasing current to the silicon controlled rectifier SCR, which turns on the circuit, and then to transistor TR1. Transistor TR1 then activates the integrated circuit IC1. In the embodiment of FIG. 4, IC1 is a 555 timer, used to achieve accurate time delays. Pin 1 on integrated circuit 1C1 is connected to ground. Pin 2 is the trigger and receives signals from transistor TR1; pin 5 is the control voltage pin; pin 6 is the threshold pin; pin 7 is the discharge pin and pin 8 is connected to the power supply. When integrated circuit IC1 is triggered, the signal from pin 3 activates a second transistor TR2. Transistor TR2 then energizes the horn driver HD. The horn driver sounds the audible alarm and the SCR1 energizes the light emitting device LED1. When the tilt switch S2 is open (i.e. vending machine is at less than the preselected angle) the current flow to capacitor C1 and transistor TR1 stops. Capacitor C1 continues to keep transistor TR1 energized while capacitor C1 discharges. Switching diodes D1 and D2 allow the capacitor C1 discharge current to flow until the voltage drops below a certain level (for example, 3 volts). At that point, switching diode D1 no longer conducts and current to transistor TR1 stops. The integrated circuit IC1 operates in this time delay mode as follows. External capacitor C 2 is initially held discharged by a transistor inside integrated circuit IC1. Upon the triggering of pin 2, the flip-flop is set which both releases the short circuit across the capacitor and drives the output on pin 3 high. The voltage across capacitor C 2 then increases exponentially for a period of t=1.1R 4 C 3 at the end of which time the voltage across capacitor C 2 equals two thirds of power supply voltage The comparator then resets the flip-flop which in turn discharges the capacitor and drives the output to its low state. When current to transistor TR1 stops transistor TR1 no longer triggers pin 2 of integrated circuit IC1. A comparator inside integrated circuit IC1 resets the flip-flop, which in turn discharges the capacitor C 2 . This discharge operates to delay the changing of the output pin 3 to a low state. When the output pin 3 of integrated circuit IC1 turns off, the horn driver HD is de-energized, thereby silencing the horn. Light emitting diode LED1 remains lit indicating that an alarm condition did occur. In order to test the battery voltage, one pushes push button 110 which sends current to light emitting diode LED 2 which then energizes. Resistors R7 and R4 and zener diode ZD1, drops the voltage to light emitting diode LED2 so that light emitting diode LED2 will not light up if the voltage is less than a certain amount (here, 12 volts) at the source, batteries 70. This indicates low voltage and the battery should be replaced.

A vending machine is disclosed which is protected from theft or pilferage through an alarm device contained within the vending machine. The alarm device is mounted within the vending machine and sounds an alarm when the vending machine is moved or tilted more than a certain amount for a predetermined period of time. The alarm device is inexpensive, compact and easy to install requiring little modification to existing vending machines.

BACKGROUND OF THE INVENTION (a) Technical Field of the Invention The present invention generally relates to means for inserting collar stay into a shirt collar, and more particularly to an automatic collar stay insertion device for a flat knitting machine. (b) Description of the Prior Art As technology advances, the manufacturing processes of the textile industry are pretty much automated so as to reduce production cost and to increase the production capacity. During the making of a shirt, despite that most of the work is carried out without human labor, the placement of the collar stays inside the spread collar of the shirt at the positions shown in FIG. 1 , at the present time, still requires human involvement, which significantly limits the production efficiency of the shirts. SUMMARY OF THE INVENTION The primary purpose of the present invention is to provide an automatic collar stay insertion device, which comprises a static member, a positioning member, and a collar stay supply member. The static member is mounted on a flat knitting machine. The other two parts are driven by motors. The positioning member utilizes the gears to rotate and move the moving plate. The sensor detects the detecting plate on the moving plate to control the position of the moving plate. The groove on the moving plate is then aligned with the place where the collar stay is to be inserted. The collar stay supply member utilizes a bevel gear to transport the power to the post with threaded so that the moving base on the post with threaded is moved therewith. The pushing post then pushes the collar stay in the collar stay case toward the place where the collar stay is to be inserted. The flat knitting machine with the automatic collar stay insertion device of the invention is automatically inserting a collar stay into a shirt collar through editing computer program. The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawing in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic view of a conventional device; FIG. 2 is a perspective view of a device of the invention; FIG. 3 is perspective view of a device of the invention; FIG. 4 is a schematic view of a device of an embodiment of the invention; FIG. 5 is a schematic view of a device of an embodiment of the invention; FIG. 6 is a schematic view of a device of an embodiment of the invention; FIG. 7 is a schematic view of a device of an embodiment of the invention; FIG. 8 is a schematic view of a device of an embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. An automatic collar stay insertion device of the present invention mainly comprises a static member, a positioning member, and a collar stay supply member. For an embodiment of the automatic collar stay insertion device as shown in FIGS. 2 to 4 , the static member comprises a block 10 slidably mounted around a horizontal rail 11 of a flat knitting machine so that the block 10 can be slid along the horizontal rail 11 to an appropriate position. The block 10 is then fixed at the position by fastening two bolts through two threaded holes on the top and bottom surfaces of the block 10 , respectively, against the horizontal rail 11 . An L-shape plate 12 for the positioning member and the collar stay supply member is fixed on the block 10 . The positioning member and the collar stay supply member are fixed on the L-shape plate 12 . Two motors 20 and 30 are mounted on the L-shape plate 12 . The positioning member utilizes a gear 21 to connect to a shaft of the motor 20 . The gear 21 drives an assisting gear 23 disposed on the assisting shaft 22 . The assisting gear 23 engages the rack at an end of the moving plate 40 so that the moving plate 40 connects to the motor 30 is rotatable therewith. Due to the moving plate 40 is disposed between the motor shafts by bearing 41 , the motor 30 rotates without affecting the moving plate 40 . The moving plate 40 is rotatable to move or to position via a detecting plate 42 screwed thereon and a sensor 50 fixed on the L-shape plate 12 for controlling the motor. The collar stay supply member utilizes a bevel driving gear 31 to connect to a shaft of the motor 30 . The bevel driving gear 31 is disposed between the motor 30 and the moving plate 40 and cooperates with a bevel driven gear 32 disposed at an end of a post with threaded 33 . The post with threaded 33 and the sleeve 34 are fixed on the moving plate 40 by screw. A moving base 35 is slidably disposed on the post with threaded 33 . A side edge of the moving base 35 plugs into a square opening of a guiding groove 43 with a pushing post 36 therein. When motor drives the gears and the post with threaded 33 , the moving base 35 moves therewith. The pushing post 36 is then moved with the moving base 35 . The collar stay case 37 is disposed in the groove 44 of the moving plate 40 by screws 51 and connectors 52 . The slot on the collar stay case 37 engages to the guiding groove 43 so that the collar stay 60 in the collar stay case 37 is pushed out of the guiding groove 43 while the pushing post 36 moves in the guiding groove 43 . The sensor 53 on the moving plate 40 detects the position of the moving base 35 on the post with threaded 33 to control the movement of the pushing post 36 . Referring to FIG. 5 to FIG. 8 , the automatic collar stay insertion device of the invention is installed in a flat knitting machine and is programmed by digital computer program. When knitted, the flat knitting machine is temporary stopped at the position inserting the collar stay. The motor 20 is then driven and the gears are cooperated with each other. The sensor 50 detects the position of the detecting plate 42 of the moving plate 40 . The moving plate 40 is then rotated so that the guiding groove 43 on the moving plate 40 aligns with the place where the collar stay is inserted. The motor 30 drives the bevel gears to transport the power to the post with threaded 33 , thereby moves the moving plate 35 on the post with threaded 33 and the pushing post 36 so that the collar stay in the collar stay case 37 is pushed toward the place where the collar stay is inserted from the groove. The sensor 53 on the moving plate 40 detects the position of the moving base 35 . The motor 30 is then operated counter to move the moving base 35 and the pushing post 36 in opposite direction. The other sensor on the moving plate 40 is actuated. When the sensor detects the position on the moving base 35 , the motor 30 is stop and the moving base 35 and the pushing post 36 move back to the original position. The motor 20 is then operated counter to move the moving plate 40 back to the original position by the gears and the detecting plate 42 . As mentioned, the automatic knitting process of the flat knitting machine is completed. In sum, the collar stay insertion device of the invention is utilized in a flat knitting machine with automatic processing. The motors and the gears are used to rotate, position, and supply the collar stay. A plurality of collar stay insertion devices may install in one flat knitting machine to increase efficiency. It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.

An automatic collar stay insertion device is provided herein. The device is for automatically inserting the collar stay. The device is mounted in a flat knitting machine utilizing motors and gears to rotate, locate and supply the collar stay. The conventional human involvement of inserting the collar stay is replaced by the automatic collar stay insertion device of the invention to decrease the costs and increase the product efficiency.

BACKGROUND [0001] The present invention relates generally to modular construction systems used to create buildings, such as single-family housing, multi-family housing, commercial buildings, retail buildings, restaurant and hospitality buildings, religious buildings, institutional buildings, educational buildings, etc. SUMMARY [0002] A modular construction panel according to one embodiment includes a panel having a height, opposed first and second faces, and opposed generally vertical ends. A keyway receiver is integral with the panel adjacent one of the panel ends, and a keyway spline is integral with the panel adjacent another of the panel ends. The keyway receiver includes a generally planar proximal face, a first offset face, and a second offset face. The proximal face extends generally vertically and has opposed ends. The first offset face extends from one of the proximal face ends, and the first offset face is generally vertical. The first offset face is angled relative to the proximal face to form an opening of more than ninety degrees between the first offset face and the proximal face. The second offset face extends from another of the proximal face ends, and the second offset face is generally vertical. The second offset face is angled relative to the proximal face to form an opening of more than ninety degrees between the second offset face and the proximal face. The angle of the opening between the second offset face and the proximal face is at least thirty percent greater than the angle of the opening between the first offset face and the proximal face. A generally vertical wall extends from the keyway receiver first offset face, and another generally vertical wall extends from the keyway receiver second offset face. The wall extending from the keyway receiver first offset face, the wall extending from the keyway receiver second offset face, and the proximal face are generally parallel. The wall extending from the keyway receiver second offset face is inset toward the proximal face from the wall extending from the keyway receiver first offset face. The keyway spline includes a generally planar distal face, a first offset face, and a second offset face. The distal face extends generally vertically and has opposed ends. The first offset face extends from one of the distal face ends, and the first offset face is generally vertical. The first offset face is angled relative to the distal face more than ninety degrees and less than one hundred and eighty degrees. The second offset face extends from another of the distal face ends, and the second offset face is generally vertical. The second offset face is angled relative to the distal face more than ninety degrees and less than one hundred and eighty degrees. The angle between the second offset face and the distal face is at least thirty percent greater than the angle between the first offset face and the distal face. A generally vertical wall extends from the keyway spline first offset face, and another generally vertical wall extends from the keyway spline second offset face. The wall extending from the keyway spline first offset face, the wall extending from the keyway spline second offset face, and the distal face are generally parallel. The wall extending from the keyway spline second offset face is outset toward the distal face from the wall extending from the keyway spline first offset face. [0003] A modular construction panel according to another embodiment includes a panel and a keyway receiver. The panel has a height, opposed first and second faces, and opposed first and second generally vertical ends, and the keyway receiver is integral with the panel at either the panel first end or one of the panel faces adjacent the panel first end. The keyway receiver is between first and second generally vertical walls that are either generally perpendicular to the panel faces or that comprise one of the panel faces. The keyway receiver includes a generally planar proximal face, a first offset face, and a second offset face. The proximal face extends generally vertically and has opposed first and second ends. The first offset face extends from the proximal face first end to the first wall. The first offset face is generally vertical and is angled relative to the proximal face to form an opening of more than ninety degrees between the first offset face and the proximal face. The second offset face extends from the proximal face second end to the second wall. The second offset face is generally vertical and is angled relative to the proximal face to form an opening of more than ninety degrees between the second offset face and the proximal face. The angle of the opening between the second offset face and the proximal face is at least twenty five percent greater than the angle of the opening between the first offset face and the proximal face. The second wall is inset toward the proximal face from the first wall. [0004] A modular construction panel according to still another embodiment includes a panel and a keyway spline. The panel has a height, opposed first and second faces, and opposed first and second generally vertical ends. The keyway spline is integral with the panel at either the panel first end or one of the panel faces adjacent the panel first end. The keyway spline is between first and second generally vertical walls that are either generally perpendicular to the panel faces or that comprise one of the panel faces. The keyway spline includes a generally planar distal face, a first offset face, and a second offset face. The distal face extends generally vertically and has opposed first and second ends. The first offset face extends from the distal face first end to the first wall, and the second offset face extends from the distal face second end to the second wall. The first offset face is generally vertical and is angled relative to the distal face more than ninety degrees and less than one hundred and eighty degrees; the second offset face is generally vertical and is angled relative to the distal face more than ninety degrees and less than one hundred and eighty degrees. The angle between the second offset face and the distal face is at least twenty five percent greater than the angle between the first offset face and the distal face. The second wall is outset toward the distal face from the first wall. [0005] A modular construction system according to an embodiment includes first and second panels, each having: a height; opposed first and second faces; opposed generally vertical first and second ends; a keyway receiver at either the panel first end or one of the panel faces adjacent the panel first end; and a keyway spline at either the panel second end or one of the panel faces adjacent the panel second end. The keyway receiver of each panel is between first and second generally vertical walls that are either generally perpendicular to the panel faces or that comprise one of the panel faces. The keyway spline of each panel is between third and fourth generally vertical walls that are either generally perpendicular to the panel faces or that comprise one of the panel faces. At least one of the third and fourth walls is separate from at least one of the first and second walls. The keyway receiver of each panel includes: a generally planar proximal face extending generally vertically and having opposed first and second ends; a first offset face extending from the proximal face first end to the first wall, the first offset face being generally vertical and being angled relative to the proximal face to form an opening of more than ninety degrees between the first offset face and the proximal face; and a second offset face extending from the proximal face second end to the second wall, the second offset face being generally vertical and being angled relative to the proximal face to form an opening of more than ninety degrees between the second offset face and the proximal face. The angle of the opening between the second offset face and the proximal face of each panel is at least twenty five percent greater than the angle of the opening between the first offset face and the proximal face of each panel. The second wall of each panel is inset toward the respective proximal face from the respective first wall. The keyway spline of each panel includes: a generally planar distal face extending generally vertically and having opposed first and second ends; a first offset face extending from the distal face first end to the third wall, the first offset face being generally vertical and being angled relative to the distal face more than ninety degrees and less than one hundred and eighty degrees; and a second offset face extending from the distal face second end to the fourth wall, the second offset face being generally vertical and being angled relative to the distal face more than ninety degrees and less than one hundred and eighty degrees. The angle between the second offset face and the distal face of each panel is at least twenty five percent greater than the angle between the first offset face and the distal face of each panel. The fourth wall of each panel is outset toward the respective distal face from the respective third wall. An extended wall section is formed by juxtaposing the proximal face of the first panel and the distal face of the second panel or by juxtaposing the proximal face of the second panel and the distal face of the first panel. BRIEF DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 a is a perspective view of a modular construction panel according to one embodiment. [0007] FIG. 1 b is a partial top view taken from FIG. 1 a. [0008] FIG. 1 c is a partial top view taken from FIG. 1 a. [0009] FIG. 1 d is a perspective view of FIG. 1 c. [0010] FIG. 1 e a partial perspective view taken from FIG. 1 a. [0011] FIG. 2 a is a perspective view of a modular construction panel according to another embodiment. [0012] FIG. 2 b is a partial perspective view taken from FIG. 2 a. [0013] FIG. 3 a a perspective view of a modular construction panel according to still another embodiment. [0014] FIG. 3 b is a partial perspective view taken from FIG. 3 a. [0015] FIG. 4 a is a perspective view of an extended wall section created using modular construction panels according to an embodiment. [0016] FIG. 4 b is a top view taken from FIG. 4 a and rotated. [0017] FIG. 4 c is a partial perspective view taken from FIG. 4 a , rotated, with a corner of one modular construction panel removed for illustration. [0018] FIG. 4 d is a partial perspective view taken from FIG. 4 a , rotated, with a corner of one modular construction panel removed for illustration. [0019] FIG. 4 e is a partial perspective view taken from FIG. 4 a. [0020] FIG. 5 a is a perspective view of an extended wall section created using modular construction panels according to another embodiment. [0021] FIG. 5 b is a partial perspective view of the area generally indicated in FIG. 5 a and rotated. [0022] FIG. 5 c is a top view taken from FIG. 5 b and rotated. [0023] FIG. 5 d is a partial perspective view of the area generally indicated in FIG. 5 a, rotated, with a corner of one modular construction panel removed for illustration. [0024] FIG. 5 e is a partial perspective view taken from FIG. 5 d. [0025] FIG. 5 f is a partial perspective view of the area generally indicated in FIG. 5 a, with a corner of one modular construction panel removed for illustration. [0026] FIG. 5 g is a partial perspective view taken from FIG. 5 f. DETAILED DESCRIPTION [0027] As shown in FIGS. 1 a through 1 e, a modular construction panel 100 according to one embodiment includes a panel 110 having a height 111 , opposed first and second faces 112 a , 112 b , and opposed ends 114 that are generally vertical. The height 111 may be generally consistent across the panel 110 and may be defined by a generally horizontal top plate face 116 and a generally horizontal bottom bearing face 117 . [0028] The panel 110 may be constructed of various materials, including conventional materials (e.g., wood, steel, concrete, etc.) and non-conventional materials (e.g., plastics, composites, rubbers, etc.) and may have various dimensions. For example, the distance between the faces 112 a , 112 b may be selected for structural or insulating properties. The height 111 may be chosen to correspond to a desired ceiling height, as is typical in conventional construction. The distance between the ends 114 may be forty eight inches (or a multiple of 48 inches, such as 96 inches, 144 inches, etc.) to correspond to typical sheets of plywood used for flooring, or may be any other selected distance. [0029] A keyway receiver 120 is integral with the panel 110 adjacent one of the ends 114 . As shown in FIG. 1 b, the receiver 120 in the modular construction panel 100 is at one end 114 between generally vertical walls 115 a , 115 b that define the end 114 . The keyway receiver 120 includes a generally planar proximal face 122 that extends generally vertically and has opposed ends 122 a , 122 b . A first offset face 124 a extends between the end 122 a of the proximal face 122 and the generally vertical wall 115 a , and a second offset face 124 b extends between the end 122 b of the proximal face 122 and the generally vertical wall 115 b . The proximal face 122 , the wall 115 a , and the wall 115 b may be generally parallel to one another, and the wall 115 b may be inset toward the proximal face 122 from the wall 115 a . In other words, if respective planes were drawn to include the wall 115 a , the wall 115 b , and the proximal face 122 , the plane containing the wall 115 b may be between the other two planes. [0030] The first offset face 124 a is angled relative to the proximal face 122 to form an opening 125 a of more than ninety degrees between the first offset face 124 a and the proximal face 122 . The second offset face 124 b is angled relative to the proximal face 122 to form an opening 125 b of more than ninety degrees between the second offset face 124 b and the proximal face 122 . The angle of the opening 125 b between the second offset face 124 b and the proximal face 122 is at least twenty five percent greater than the angle of the opening 125 a between the first offset face 124 a and the proximal face 122 , and it may be preferable for the angle of the opening 125 b to be at least thirty percent greater than the angle of the opening 125 a . For example, in one embodiment, the angle of the opening 125 a is approximately 99.46 degrees and the angle of the opening 125 b is approximately 135 degrees, but it should be understood that other angles may also be used. It should also be appreciated that the first offset face 124 a may meet the proximal face 122 and/or the wall 115 a at either a point or a curve, and that the second offset face 124 b may meet the proximal face 122 and/or the wall 115 b at either a point or a curve. [0031] A keyway spline 130 is integral with the panel 110 adjacent the end 114 that is opposite the end 114 adjacent the keyway receiver 120 . As shown in FIG. 1 c, the spline 130 in the modular construction panel 100 is at one end 114 between generally vertical walls 115 c , 115 d that define the respective end 114 . The keyway spline 130 includes a generally planar distal face 132 that extends generally vertically and has opposed ends 132 a , 132 b . A first offset face 134 a extends between the end 132 a of the distal face 132 and the generally vertical wall 115 c , and a second offset face 134 b extends between the end 132 b of the distal face 132 and the generally vertical wall 115 d. The distal face 132 , the wall 115 c , and the wall 115 d may be generally parallel to one another, and the wall 115 d may be outset toward the distal face 132 from the wall 115 c. In other words, if respective planes were drawn to include the wall 115 c , the wall 115 d, and the distal face 132 , the plane containing the wall 115 d may be between the other two planes. [0032] The first offset face 134 a is angled relative to the distal face 132 more than ninety degrees and less than one hundred and eighty degrees. The angle between the first offset face 134 a and the distal face 132 is denoted in FIG. 1 c as 135 a . The second offset face 134 b is angled relative to the distal face 132 more than ninety degrees and less than one hundred and eighty degrees. The angle between the second offset face 134 b and the distal face 132 is denoted in FIG. 1 c as 135 b . The angle 135 b between the second offset face 134 b and the distal face 132 is at least twenty five percent greater than the angle 125 a between the first offset face 134 a and the distal face 132 , and it may be preferable for the angle 135 b to be at least thirty percent greater than the angle 135 a . For example, in one embodiment, the angle 135 a is approximately 94.76 degrees and the angle 135 b is approximately 129.81 degrees, but it should be understood that other angles may also be used. It should also be appreciated that the first offset face 134 a may meet the distal face 132 and/or the wall 115 c at either a point or a curve, and that the second offset face 134 b may meet the distal face 132 and/or the wall 115 d at either a point or a curve. [0033] It may be desirable for the angle 135 a to be between approximately four degrees and approximately six degrees smaller than the angle of the opening 125 a between the first offset face 124 a and the proximal face 122 , and for the angle 135 b to be between approximately four degrees and approximately six degrees smaller than the angle of the opening 125 b between the second offset face 124 b and the proximal face 122 . [0034] As shown in FIGS. 1 a through 1 e, one of the faces 112 a , 112 b of the panel 110 (e.g., face 112 a ) may be a finished face, or in other words, may include siding, stucco, masonry, or another appropriate finishing material 140 , and may be painted, sealed, or otherwise treated. The finishing material 140 may extend above the top plate face 116 ( FIG. 1 d ) and below the bottom bearing face 117 ( FIG. 1 e ), and may be at least partially outset or inset from the panel ends 114 . For example, as shown in FIGS. 1 b and 1 c, the finishing material 140 is partially outset (forming lap joint spline 142 a ) at the end 114 adjacent the keyway receiver 120 and partially inset (forming lap joint receiver 142 b ) at the end 114 adjacent the keyway spline 130 . The wall 115 a may be longer than the wall 115 b , placing the keyway receiver 120 closer to the interior face (e.g., face 112 b ) of the panel 110 than to the exterior face (e.g., face 112 a ), and the wall 115 c may be longer than the wall 115 d , placing the keyway spline 130 closer to the interior face (e.g., face 112 b ) of the panel 110 than to the exterior face (e.g., face 112 a ). [0035] Though not specifically shown in the drawings, it should be understood that the panel 110 may include one or more window, one or more door, insulation, and/or other traditional building components. The panel 110 may be constructed in accordance with building codes to be load bearing, and may be “open-walled”, which allows the modular construction panel 100 to be inspected by local building officials and meets national housing lending requirements for buyers to qualify for conventional home loan financing. [0036] FIGS. 2 a and 2 b show another embodiment of a modular construction panel, denoted by reference number 200 . The modular construction panel 200 is generally similar to the modular construction panel 100 , except for as set forth herein, shown in the drawings, and/or inherent. Elements of the modular construction panel 200 that are specifically discussed as being different from those of the modular construction panel 100 have reference numbers between 200 and 299. [0037] The modular construction panel 200 includes a keyway spline 230 instead of the keyway spline 130 . The keyway spline 230 is integral with the panel 110 adjacent the end 114 that is opposite the end 114 adjacent the keyway receiver 120 . As shown in FIG. 2 b , the keyway spline 230 in the modular construction panel 200 is at one face (e.g., face 112 b ) between generally vertical walls 215 c , 215 d that define the face (e.g., face 112 b ). The keyway spline 230 includes a generally planar distal face 232 that extends generally vertically and has opposed ends 232 a , 232 b . A first offset face 234 a extends between the end 232 a of the distal face 232 and the generally vertical wall 215 c , and a second offset face 234 b extends between the end 232 b of the distal face 232 and the generally vertical wall 215 d . The distal face 232 , the wall 215 c , and the wall 215 d may be generally parallel to one another, and the wall 215 d may be outset toward the distal face 232 from the wall 215 c . In other words, if respective planes were drawn to include the wall 215 c , the wall 215 d , and the distal face 232 , the plane containing the wall 215 d may be between the other two planes. [0038] The first offset face 234 a is angled relative to the distal face 232 more than ninety degrees and less than one hundred and eighty degrees. The angle between the first offset face 234 a and the distal face 232 is denoted in FIG. 2 b as 235 a . The second offset face 234 b is angled relative to the distal face 232 more than ninety degrees and less than one hundred and eighty degrees. The angle between the second offset face 234 b and the distal face 232 is denoted in FIG. 2 b as 235 b . The angle 235 b between the second offset face 234 b and the distal face 232 is at least twenty five percent greater than the angle 225 a between the first offset face 234 a and the distal face 232 , and it may be preferable for the angle 235 b to be at least thirty percent greater than the angle 235 a . For example, in one embodiment, the angle 235 a is approximately 94.76 degrees and the angle 235 b is approximately 129.81 degrees, but it should be understood that other angles may also be used. [0039] It may be desirable for the angle 235 a to be between approximately four degrees and approximately six degrees smaller than the angle of the opening 125 a between the first offset face 124 a and the proximal face 122 , and for the angle 235 b to be between approximately four degrees and approximately six degrees smaller than the angle of the opening 125 b between the second offset face 124 b and the proximal face 122 . [0040] As in the modular construction panel 100 , the finishing material 140 may extend above the top plate face 116 and below the bottom bearing face 117 , and may be at least partially outset or inset from the panel ends 114 . For example, as shown in FIGS. 2 a and 2 b , the finishing material 140 is partially outset (forming lap joint spline 142 a ) at the end 114 adjacent the keyway receiver 120 and partially inset (forming lap joint receiver 142 b ) at the end 114 adjacent the keyway spline 230 . The wall 215 d may be longer than the wall 215 c so that the keyway spline 230 may interact with a keyway receiver 120 as set forth in additional detail below. [0041] FIGS. 3 a and 3 b show another embodiment of a modular construction panel, denoted by reference number 300 . The modular construction panel 300 is generally similar to the modular construction panel 100 , except for as set forth herein, shown in the drawings, and/or inherent. Elements of the modular construction panel 300 that are specifically discussed as being different from those of the modular construction panel 100 have reference numbers between 300 and 399. [0042] The modular construction panel 300 includes a keyway spline 330 instead of the keyway spline 130 . The keyway spline 330 is integral with the panel 110 adjacent the end 114 that is opposite the end 114 adjacent the keyway receiver 120 . As shown in FIG. 3 b, the keyway spline 330 in the modular construction panel 300 is at one face (e.g., face 112 a ) between generally vertical walls 315 c , 315 d that define the face (e.g., face 112 a ). The keyway spline 330 includes a generally planar distal face 332 that extends generally vertically and has opposed ends 332 a , 332 b . A first offset face 334 a extends between the end 332 a of the distal face 332 and the generally vertical wall 315 c , and a second offset face 334 b extends between the end 332 b of the distal face 332 and the generally vertical wall 315 d . The distal face 332 , the wall 315 c , and the wall 315 d may be generally parallel to one another, and the wall 315 d may be outset toward the distal face 332 from the wall 315 c . In other words, if respective planes were drawn to include the wall 315 c , the wall 315 d , and the distal face 332 , the plane containing the wall 315 d may be between the other two planes. [0043] The first offset face 334 a is angled relative to the distal face 332 more than ninety degrees and less than one hundred and eighty degrees. The angle between the first offset face 334 a and the distal face 332 is denoted in FIG. 3 b as 335 a . The second offset face 334 b is angled relative to the distal face 332 more than ninety degrees and less than one hundred and eighty degrees. The angle between the second offset face 334 b and the distal face 332 is denoted in FIG. 3 b as 335 b . The angle 335 b between the second offset face 334 b and the distal face 332 is at least twenty five percent greater than the angle 335 a between the first offset face 334 a and the distal face 332 , and it may be preferable for the angle 335 b to be at least thirty percent greater than the angle 335 a . For example, in one embodiment, the angle 335 a is approximately 94.76 degrees and the angle 335 b is approximately 129.81 degrees, but it should be understood that other angles may also be used. [0044] It may be desirable for the angle 335 a to be between approximately four degrees and approximately six degrees smaller than the angle of the opening 125 a between the first offset face 124 a and the proximal face 122 , and for the angle 335 b to be between approximately four degrees and approximately six degrees smaller than the angle of the opening 125 b between the second offset face 124 b and the proximal face 122 . [0045] As in the modular construction panel 100 , the finishing material 140 may extend above the top plate face 116 and below the bottom bearing face 117 , and may be at least partially outset or inset from the panel ends 114 . For example, the finishing material 140 is partially outset (forming a lap joint spline) at the end 114 adjacent the keyway receiver 120 and inset (forming lap joint receiver 142 b , as shown in FIG. 3 b ) at the end 114 adjacent the keyway spline 330 . The wall 315 c may be longer than the wall 315 d so that the keyway spline 330 may interact with a keyway receiver 120 as set forth in additional detail below. [0046] FIGS. 4 a through 4 e show one way that the three modular construction panels 100 , 200 , 300 may be used to create an extended wall section (e.g., closed perimeter 400 ) if the modular construction panels 100 , 200 , 300 do not include a finished face, or in other words, do not include finishing material 140 . It should be appreciated that the three modular construction panels 100 , 200 , 300 may be arranged to form perimeters having various configurations, and that the perimeter 400 is only exemplary. Focusing on FIGS. 4 b through 4 e, it can be seen that the keyway receivers 120 and the keyway splines 130 , 230 , 330 interact to couple adjacent modular construction panels 100 , 200 , 300 together. More particularly, the distal face 132 of the keyway spline 130 of one modular construction panel 100 is juxtaposed with the proximal face 122 of the keyway receiver 120 of one modular construction panel 300 ( FIG. 4 b ); the distal face 332 of the keyway spline 330 of the modular construction panel 300 is juxtaposed with the proximal face 122 of the keyway receiver 120 of one modular construction panel 200 ( FIG. 4 c ); the distal face 232 of the keyway spline 230 of the modular construction panel 200 is juxtaposed with the proximal face 122 of the keyway receiver 120 of another modular construction panel 100 ( FIG. 4 d ); and the distal face 132 of the keyway spline 130 of one modular construction panel 100 is juxtaposed with the proximal face 122 of the keyway receiver 120 of another modular construction panel 100 ( FIG. 4 e ). The configurations of the keyway receivers 120 and the keyway splines 130 , 230 , 330 may allow a respective panel 110 to be rotated into place relative to an adjacent stationary panel 110 . Top plates are coupled (e.g., nailed or screwed) to the top plate faces 116 to further secure the modular construction panels 100 , 200 , 300 to one another. [0047] It should be clear that any number and combination of modular construction panels 100 , 200 , 300 may be transported to the construction site and joined in this manner if finishing material 140 is not included, and that only the three types of standard modular construction panels 100 , 200 , 300 are required. Once the perimeter 400 is formed, the building may be constructed traditionally. In other words, a roof or second floor may be supported by the modular construction panels 100 , 200 , 300 ; exterior sides of the modular construction panels 100 , 200 , 300 may be finished with an exterior material; plumbing, air ducts, electricity, and insulation may be placed inside the modular construction panels 100 , 200 , 300 ; interior sides of the modular construction panels 100 , 200 , 300 may be finished with drywall or another interior material; etc. If a second floor is added, it may have a perimeter comprised of additional modular construction panels 100 , 200 , 300 . To maintain standard construction dimensions, it may be desirable to include additional panels of different lengths; for example, panels 100 that interact with splines 230 may be shorter than other panels 100 . [0048] FIGS. 5 a through 5 g show another way that the modular construction panels 100 , 200 , 300 may be used to create an extended wall section (e.g., closed perimeter 500 ) if the modular construction panels 100 , 200 , 300 each includes a finished face (i.e., finishing material 140 ). It should be appreciated that the modular construction panels 100 , 200 , 300 may be arranged to form perimeters having various configurations, and that the perimeter 500 is only exemplary. [0049] If each modular construction panel 100 , 200 , 300 includes a single finished face, then three distinct configurations of the modular construction panel 100 are required in a basic embodiment, resulting in five distinct modular construction panels. More specifically, a first configuration 100 ′ ( FIGS. 5 b and 5 c ) of the modular construction panel 100 has finishing material 140 that is partially outset (forming lap joint spline 142 a ) at the end 114 adjacent the keyway receiver 120 for interacting with a lap joint receiver 142 b; a second configuration 100 ″ ( FIGS. 5 d and 5 e ) of the modular construction panel 100 has finishing material 140 that is entirely offset (forming extension 142 a ″) for covering an end 114 of the modular construction panel 200 ; and a third configuration 100 ′″ ( FIGS. 5 f and 5 g ) of the modular construction panel 100 has finishing material 140 that is at least partially inset (forming lap joint receiver 142 a ′″) for mating with finishing material 140 of the modular construction panel 300 . Each of the configurations 100 ′, 100 ″, 100 ′″ of the modular construction panel 100 may have finishing material 140 that is partially inset (forming lap joint receiver 142 b ) at the end 114 adjacent the keyway spline 130 ( FIG. 1 c ). [0050] As such, in the basic pre-finished embodiment, configuration 100 ″ of the modular construction panel 100 must be used only with the modular construction panel 200 to form an outside corner (i.e., though interaction between keyway receiver 120 and keyway spline 230 , as set forth above), and configuration 100 ′″ of the modular construction panel 100 must be used only with the modular construction panel 300 to form an inside corner (i.e., through interaction between keyway receiver 120 and keyway spline 330 , as set forth above). Configuration 100 ′ of the modular construction panel 100 may be used with any of the modular construction panels 100 (i.e., configuration 100 ′, configuration 100 ″, or configuration 100 ′″) to form an extended wall section that is straight (i.e., through interaction between keyway receiver 120 and keyway spline 130 . Especially at the corners (i.e., where a modular construction panel 100 meets a modular construction panel 200 to form an outside corner and where a modular construction panel 100 meets a modular construction panel 300 to form an inside corner), trim, caulk, or another finishing material may cover a portion of the finish material 140 . Exemplary trim 149 is shown only in FIG. 5 a. [0051] It should be appreciated that in a more complex pre-finished embodiment, additional configurations of the modular construction panels 200 , 300 may be included that are similar to configurations 100 ″, 100 ′″ so that modular construction panels 200 , 300 may be coupled to one another. It should also be understood that other embodiments may include finishing material 140 on more than one side of a respective panel 110 , and that the finishing material 140 on other panels 110 may need to be altered as a result. [0052] Those skilled in the art appreciate that variations from the specified embodiments disclosed above are contemplated herein and that the described embodiments are not limiting. The description should not be restricted to the above embodiments, but should be measured by the following claims.

Modular construction panels, systems, and methods of installation are set forth for use in creating buildings. A modular construction panel includes a panel having a height, opposed faces, and opposed generally vertical ends. In one embodiment, a keyway receiver is integral with the panel adjacent one of the ends, and a keyway spline is integral with the panel adjacent the other end. In another embodiment, a keyway receiver is integral with the panel adjacent one of the ends. In still another embodiment, a keyway receiver is integral with the panel adjacent one of the ends. One modular construction system includes first and second panels, each having: a height, opposed faces, opposed generally vertical first and second ends, a keyway receiver at the first end or one of the faces adjacent the first end, and a keyway spline at the second end or one of the faces adjacent the second end.

BACKGROUND OF THE INVENTION This invention relates generally to devices for supporting bags, and more particularly concerns an easily molded, improved handle usable to quickly, firmly, and reliably support and retain the narrow plastic handle strands of one or more flimsy plastic bags, and simultaneously. It is known that flimsy plastic bags, as for example are currently used by many grocery stores and other retail outlets, afford the user a convenient means of transporting small and medium sized objects; however, such bags can, at times, and depending on the number of bags and the weight of each, become difficult and uncomfortable to carry, simultaneously. Also, such bags tend to spill their contents when resting on vibrating surfaces, such as vehicle floors. There is need for means co-operable with the narrow flimsy plastic handle straps of such flimsy bags, in such manner as to obviate the above problems, and also to carry filmsy bag straps in a secure manner. SUMMARY OF THE INVENTION It is a major object of the invention to provide a unitary, durable, molded plastic handle constructed to meet the above need. It is another object to provide such a unitary handle capable of supporting and carrying the flimsy plastic straps of one or more plastic bags, and at spaced locations, the handle also having a ribbed construction between such spaced locations, and which may be surface textured, to provide a comfortable, secure grip for the user's hand. It is a further object to provide bag strap retention means on a handle and characterized in that once the straps are inserted into retention gaps, they are effectively locked in place against accidental removal, and until such time as they are deliberately removed, normally. It is yet another object to provide a handle as referred to which secures the tops of flimsy bags in semi-closed position or positions, reducing the chance of damage to articles in the bag or bags and preventing spillage of the articles from the bag or bags. Another object is the provision of a handle configuration that allows bags to be transported with the two straps of each bag located respectively forwardly and rearwardly relative to the user's walk direction, whereby the bag or bags may be carried with their larger width dimensions parallel to the user's body. Basically, the improved handle comprises: (a) a handle body which is horizontally, longitudinally elongated and has opposite ends, front and rear sides, and top and bottom surfaces, the body having opposite end portions and an intermediate portion between said end portions, (b) there being recesses extending downwardly at said end portions from said top surfaces and terminating within said end portions, said recesses intersecting said front and rear sides, (c) the handle body defining local protuberances extending in the length direction of said handle and into the recesses, the widths of the recesses being narrowed by said protuberances to form gaps spaced above the lowermost extents of the recesses. Typically, there are two pairs of such protuberances, the protuberances of a first pair extending longitudinally oppositely and into one recess, and the protuberances of the second pair extending longitudinally oppositely and into the other recess, a gap being formed between the protuberances of each pair. Also, each recess typically has opposite vertical walls from which the two protuberances project toward one another, the protuberances having undersides normal to such walls; and, one of each such walls of a recess having a vertical dimension substantially greater than the vertical dimension of the other wall, said one vertical wall located closer to the end of the handle than said other vertical wall. Further, the protuberances at each gap typically have upper surfaces which taper downwardly and toward one another. It is a further object to provide re-entrant side recesses formed in the handle body to intersect said front and rear body sides, said recesses spaced in succession along the length of the body, there being ribs formed between successive of said recesses and located to be normally grasped when the user's hand closes about the handle. In this regard, the handle body typically may formed generally vertical ribs located in longitudinal succession at said front and rear body sides, and between said gaps. Finally, the body may form through openings intersecting said front and rear sides, and proximate said gaps, for reception of a shoulder strap to be carried by the user. These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which: DRAWING DESCRIPTION FIG. 1 is a side elevation showing a handle incorporating the invention; FIG. 2 is a top plan view taken on lines 2--2 of FIG. 1; FIG. 3 is a bottom plan view taken on lines 3--3 of FIG. 1; FIG. 4 is a section taken on lines 4--4 of FIG. 1; FIG. 5 is an end view taken on lines 5--5 of FIG. 1; FIG. 6 is an elevation showing a flimsy plastic bag with straps supported by the FIG. 1 handle; and FIG. 7 is a fragmentary side view showing shoulder strap support of modified handle that also has the features of the FIG. 1 handle. DETAILED DESCRIPTION In the drawings, the molded, hard plastic handle 10 is adapted to support a flimsy thin plastic (polyethylene film, for example) grocery type bag 11 as seen in FIG. 6. That bag has loop shaped straps or strands 12 and 13 which are flimsy, yet strong and supported by the handle, as shown. The handle body 15 is horizontally longitudinally elongated, and has opposite ends 16 and 17, front and rear sides 18 which are alike, and top and bottom surfaces 19 and 20. Also, the body has opposite end portions 21 and 22, and an elongated intermediate portion 23. The handle body top surface 19 is substantially horizontal between end portions 21 and 22, and the bottom surface 20 associated with intermediate portion 23 is downwardly convex at a middle section 20a, and downwardly concave at sections 20b, between 20a and opposite end portions 21 and 22. The handle body includes re-entrant recesses 25 formed in front and rear sides of the body, and which are vertically elongated and spaced lengthwise along the handle body length. Such recesses intersect that front and rear upright sides of the body so that a series of vertical ribs 26 is formed at each side of the body. Such ribs are easily grasped, normally, to prevent slippage of the user's hand on and particularly lengthwise along the body. The ribs may have convex outermost surfaces as at 26a, and those surfaces may be textured in a manner similar to knurling, as at 26b, to increase the user's grip. The bottoms of the recesses, seen at 26c extend and define parallel and vertical planes 27 and 28 between which a unitary strut is formed to extend lengthwise of the handle body, and interiorly thereof. The ribs 26, and body top and bottom portions that are free of recesses, provide reinforcing, whereby a sturdy, unbending, lightweight, unitary handle is formed, and is easily moldable. Note larger recesses 30a, 30b and 30c at each of the end portions 21 and 22, and associated ribs 31-33. The handle body also includes through slots or recesses 36 extending downwardly at each of the end portions, from the top surface 19, and terminating within each end portion at bag strap support surfaces 37. The latter are upwardly crowned or crested as seen in FIG. 5, and extend between the front and rear sides 18, as do the recesses 36. Top surface 19 is also crowned, widthwise. The handle body also defines local protuberances 38 and 39 extending in the length direction of the handle, and into the recesses at their uppermost extents. The widths of the recesses are narrowed by the protuberances to form gaps 40 spaced above the lowermost extents of the recesses. Note that the top surfaces 40a of the protuberances taper downwardly to ease entry of the bag straps into the recesses below the protuberances; also, the bottom surfaces 40b of the protuberances are normal to the recess vertical walls 41 and 42, to prevent movement of the trapped straps 12 toward the gaps and at the recesses. Wall 41 is taller than wall 42, and extends adjacent the upward protuberances 43 that blocks sliding of the straps off an end of the handle, when the straps are above the gap. The recesses are adapted to receive the straps of more than one bag, whereby the handle can support multiple bags. FIG. 7 shows a modified handle body 115 having enlarged openings 116 extending through it, at each end portion, for passing or receiving a shoulder strap 117 to be carried by the user. Finally, the handle can be traveled along the retained bag straps toward the open upper end of the bag or bags, and then secured close to the open end of the bag, serving to close it, as for example by twisting the handle with its retained straps, about a vertical axis. The protuberances prevent strap release from the recesses, during such handle movement. That handle "down" position is indicated in broken lines 10' in FIG. 6, and the vertical axis of twist appears at 140. End portions 21 and 22 have flat bottom surfaces at 21' and 22'. In operation, the handle and bag straps are manipulated to allow the plastic straps to feed over and downwardly along the upper surfaces of the protuberances, and through the gaps, under loading exerted by the bag and articles carried therein, and seating said straps at the bottom of said recesses. Further, the handle may be slid along the bag straps to pass the straps endwise through the two recesses, to thereby displace the handle toward the top of the bag, tending to close the bag. Thereafter, the handle may be twisted to twist the bag straps, tending to further close the bag.

An easily molded plastic handle is usable to quickly, firmly and reliably support and retain the narrow flimsy plastic handle strands of one or more plastic bags, and to close such bags.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims priority under 35 USC 119(e) of U.S. Provisional Application No. 61/039,912, filed Mar. 27, 2008, the contents of which are herein incorporated by reference. FIELD OF THE INVENTION [0002] This invention relates to anisotropic etching of substrates, and in particular deep reactive ion etching. BACKGROUND OF THE INVENTION [0003] The so-called “Bosch Process” described in U.S. Pat. Nos. 5,501,893 and 6,127,273, the contents of which are herein incorporated by reference, is for anisotropic etching. This process uses a patterned mask deposited on top of the substrate. The mask needs to be selective to the etching chemistry used for etching the substrate. Then, in an Inductively Coupled Plasma (ICP) system, two plasma conditions are alternated between deposition phase and etching phase. The deposition is done using a gas that deposits a Teflon-like polymer (normally C 4 F 8 is used) and the etching is normally performed using a fluorine gas to attack the silicon substrate (normally SF 6 ). During the etch cycle, RF power is applied on the substrate to generate an electric field that causes ion bombardment on the bottom of the etch feature (cavity or trench). This removes the polymer only on the bottom of the etch feature and not on the sidewalls. Repeating alternate etching and deposition phases generates an anisotropic etched feature. FIG. 1 shows the sequence diagram of the standard Bosch Process. [0004] The Bosch process normally uses pressure between 5 and 100 mTorr. When the etch rate is the main concern for productivity purposes, and sidewall roughness is acceptable to some extent, increasing the pressure above 100 mTorr and increasing the ratio between etching time and deposition time are both solutions to achieving a higher etch rate with the same equipment (generally an Inductively Coupled Plasma System). When performing anisotropic etching with Bosch process at high pressure, a rougher bottom surface is observed. This is the root cause for a well-known defect in Deep Reactive Ion Etching (DRIE), which is named “grass”. This also generates non-uniformities across the wafer because the roughness is rarely uniform across the wafer. This roughness also causes unwanted sidewall roughness. [0005] The most common technique in the micro fabrication industry used for the fabrication of patterned masks is the photolithography technique. FIG. 2 shows an example of how to make the patterned mask. Many other techniques can be used but we will limit our explanation to only one. A silicon wafer substrate is normally used. Then, a photoresist is dispensed on top of the wafer using spin coating technique. A quartz plate with a pattern made of metal on top of it is placed between a shining light and the substrate. Regions in the photoresist where the light reaches the substrate get altered and become soluble. The wafer is then immersed in a liquid (a developer) that can dissolve selectively these altered regions. What is left is an image made of photoresist that is identical to the metal pattern that was on the quartz plate. The outcome of these steps is the sample that is used for anisotropic etching (entered in the ICP chamber in FIG. 1 ). [0006] FIG. 3 is a schematic representation of a cross-section of the sample in a standard Bosch process during the three key moments of the first cycle. In order from top to bottom: at the end of the deposition showing the substrate 10 , the photoresist 12 , and the polymer layer 14 , during the etch step after the polymer 14 is completely removed from the bottom, and at the end of the etch step showing the resulting partly formed trench 16 a. [0007] FIG. 4 shows a schematic representation of the steps that the sample encounters during the second cycle of the sequence shown in FIG. 1 when the answer to the question after the first cycle is “NO”. This is called the first scallop of the etching. The trench is further extended as shown at 16 b. [0008] FIG. 5 shows a schematic representation of the steps that the sample encounters during the third cycle of the sequence shown in FIG. 1 the answer to the question after the second cycle is “NO”. FIG. 6 shows the sample after 7 cycles of Standard Bosch Process when successive trench portions 16 a to 16 n are formed after each cycle. This is repeated until the right depth is obtained. The result is an anisotropic etched feature. [0009] To create smooth sidewalls and soft roughness on the bottom of the etch feature, it is generally recommended to use etch pressure between 1 to 40 mTorr. To increase etch rate with that technique the following measures are commonly used: a. Increasing pressure on the etch cycle between 40 mTorrs and 1 Torrs. b. Increasing the ratio between the time of etch and the time of deposition in each cycle. c. Increasing the etching gas flow. d. Increasing the dissociation of the etching gas by using high RF power on the ICP antenna. [0014] All the above steps generally result in larger scallop dimensions. [0015] When maximizing the etch rate, items a and b are the major factors. However, they cause the following disadvantages: a. Larger roughness on the bottom of the etched feature. After many cycles, this can become dramatic and cause the well known DRIE defect called “grass”. Since deposition is deposited on a rough surface, this increases the time to remove it at the next subsequent etch cycle. It then tends to worsen the roughness as the number of cycle is increased. At one point in time, the vertical roughness defect will grow if it is not removed after each cycle. These vertical defect features are the “grass”. The roughness on the bottom of the etch feature may not be so serious, but is still. b. Since the mean free path of the ions is inversely proportional to the pressure, increasing pressure reduces the density of ions that are accelerated without collision in the plasma sheath. This reduces the efficiency of the bombardment but increases its density. During the beginning of each etch cycle; this is increasing the time needed to remove the deposition of the preceding deposition cycle, causing wall etching (wall breakage) and roughness on the bottom of the etched feature. [0018] The second disadvantage has to some extent been overcome by the company Surface Technology Systems (STS) which uses a deposition removal step at the beginning of the etch cycle. The original Bosch process was altered and the “3-Step Method” is defined by the following sequence: a. Deposition cycle b. Etch removal step. This usually uses low pressure between 5 and 40 mT and high RF power on the platen (RF power on the sample). c. Main etch step. This usually uses lower platen power. Reducing the platen power gives higher selectivity to the patterned mask (which is a valuable asset). In this step, since the deposition is removed on the bottom after step b, the pressure can be increased to increase the etch rate without the disadvantage b above. [0022] FIG. 7 is a sequence diagram of the 3-step method from STS using high pressure. FIG. 8 shows a schematic representation of the steps that the sample encounters during the first cycle of the sequence shown in FIG. 7 . Roughness is observed when using high pressure. FIG. 9 is a schematic representation of the steps that the sample encounters during the second cycle of the sequence shown in FIG. 7 when answering “NO” at the question after the first cycle. FIG. 10 is a schematic representation of the steps that the sample encounters during the third cycle of the sequence shown in FIG. 7 when answering “NO” at the question after the second cycle. [0023] As can be observed, when using the 3-Step Method at high pressure, as the cycles are added, the roughness in the bottom of the etched feature gets worse and worse. SUMMARY OF THE INVENTION [0024] This disadvantages of the 3-Step method and the standard 2-step relating to the roughness on the bottom of the etched patterned can be overcome by the in accordance with embodiments of the invention. [0025] According to the present invention there is provided a method of performing an anisotropic etch on a substrate in an inductively coupled plasma etch chamber, comprising performing a plurality of cycles of a procedure consisting essentially of the four following steps: a. depositing a protective polymer on a patterned substrate; b. performing a first low pressure etch to partially remove the deposited protective polymer at a pressure less than 40 mTorr; c. performing a high pressure etch at a pressure between 40 mT and 1000 mT to form a portion of a trench in the substrate; and d. performing a second low pressure etch at a pressure less than 40 MTorr to reduce surface roughness. [0030] In one embodiment, the platen power in the inductively coupled plasma etch chamber is greater for steps b and d than for step c and the pressure in step d is less than the pressure in step b. [0031] Suitably, the substrate is silicon. The protective polymer is deposited using C 4 F 8 gas, and the etchant gas is selected from the group consisting of SF 6 , O 2 and a combination thereof. [0032] The longer the time of etch at high pressure, the rougher is the bottom surface. The addition of a new step during the etch cycle at low pressure and at high platen power (for efficient ion bombardment) smoothes the bottom of the cavity. This leaves a flat surface prior to the next deposition in the following cycle and prevents the growth of roughness from cycle to cycle. Also, because the deposition is deposited on a flat surface, the time to remove completely the deposition in the next deposition removal step is reduced. This allows higher pressure without roughness on the bottom. Actually, the pressure where the maximum etch rate is obtained can be used with minimal roughness. Because the deposition removal step is reduced, this further increases the etch rate and minimizes attack on the sidewalls. [0033] An important advantage of this technique is that by using this extra step, the limitation at high pressure is minimized. This gives smoother sidewall and bottom features at fast etch rates. Furthermore, by limiting the non-uniformity on the etch rate across the wafer because of the roughness, embodiments of this invention result in a reduction on the depth non-uniformity across the wafer. [0034] The Radio Frequency (RF) coil matching network unit needs to be able to react to the fast change of plasma conditions. Reducing the pressure rapidly corresponds to a fast change in impedance and therefore the matching network unit needs to react fast on such changes. The addition of an extra bombardment step reduces the mask selectivity. BRIEF DESCRIPTION OF THE DRAWINGS [0035] The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which: [0036] FIG. 1 is a sequence diagram of the standard Bosch process; [0037] FIG. 2 is a schematic representation in cross-section of the photolithography process normally used to make the patterned mask; [0038] FIG. 3 is a schematic representation of the cross-section of the sample under a standard Bosch process during the 3 key moments of the first cycle. In order from top to bottom: at the end of the deposition, during the etch step after the polymer is completely removed from the bottom, and at the end of the etch step; [0039] FIG. 4 is a schematic representation of the cross-section of the sample under a standard Bosch process during the 3 key moments of the first cycle. In order from top to bottom: at the end of the deposition, during the etch step after the polymer is completely removed from the bottom, and at the end of the etch step; [0040] FIG. 5 is a schematic representation of the cross-section of the sample under a standard Bosch process during the 3 key moments of the first cycle. In order from top to bottom: at the end of the deposition, during the etch step after the polymer is completely removed from the bottom, and at the end of the etch step; [0041] FIG. 6 is a schematic representation of the cross-section of the sample under a standard Bosch process after 7 cycles; [0042] FIG. 7 is a sequence diagram of the 3 step STS modified Bosch Process; [0043] FIG. 8 is a schematic representation of the cross-section of the sample under 3-step Bosch Process during the 3 key moments of the first cycle. In order from top to bottom: at the end of the deposition, during the etch step after the polymer is completely removed from the bottom, and at the end of the etch step; [0044] FIG. 9 is a schematic representation of the cross-section of the sample under 3-step Bosch Process during the 3 key moments of the second cycle. In order from top to bottom: at the end of the deposition, during the etch step after the polymer is completely removed from the bottom, and at the end of the etch step; [0045] FIG. 10 is a schematic representation of the cross-section of the sample under 3-step Bosch Process during the 3 key moments of the third cycle. In order from top to bottom: at the end of the deposition, during the etch step after the polymer is completely removed from the bottom, and at the end of the etch step; [0046] FIG. 11 is a sequence diagram of the invention of a four step process in accordance with an embodiment of the invention; [0047] FIG. 12 is a schematic representation of the cross-section of the sample under 4-step process in accordance with an embodiment of the invention during the four key moments of the first cycle. In order from top to bottom: at the end of the deposition, during the etch step after the polymer is completely removed from the bottom, and at the end of the etch step; [0048] FIG. 13 is a schematic representation of the cross-section of the sample under 4-step process in accordance with an embodiment of the invention during the 3 key moments of the second cycle. In order from top to bottom: at the end of the deposition, during the etch step after the polymer is completely removed from the bottom, and at the end of the etch step; [0049] FIG. 14 is a schematic representation of the cross-section of the sample under 4-step process during the 3 key moments of the third cycle. In order from top to bottom: at the end of the deposition, during the etch step after the polymer is completely removed from the bottom, and at the end of the etch step; [0050] FIG. 15 is a SEM micrograph of a cavity on the center of the Sample A. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut; [0051] FIG. 16 is a SEM micrograph of a cavity on the top (opposite to major flat) of the Sample A. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut; [0052] FIG. 17 is a SEM micrograph of a cavity on the right hand side (considering the major flat on the bottom) of the Sample A. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut; [0053] FIG. 18 is a SEM micrograph of a cavity on the center of the Sample B. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut; [0054] FIG. 19 is a SEM micrograph of a cavity on the top (opposite to major flat) of the Sample B. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut. [0055] FIG. 20 SEM micrograph of a cavity on the right hand side (considering the major flat on the bottom) of the Sample B. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut; [0056] FIG. 21 is a comparison of wall roughness between FIG. 17 (above from Sample A) and FIG. 20 (below from Sample B) on the same site on each sample. The inlet of each image shows the whole cross-section; [0057] FIG. 22 is a microscope image on the two worst dice of the wafer in term of roughness for the Sample A. Left hand side image: Top of the wafer. Right hand side: Right of the wafer; [0058] FIG. 23 is a microscope image on the two worst dice of the wafer in term of roughness for the Sample B. Left hand side image: Top of the wafer. Right hand side: Right of the wafer; [0059] FIG. 24 shows the measured dimensions on SEM micrograph for the evaluation of the profile angle. The inlet shows a diagram of the shape at the bottom of a square cavity. The 3 black lines show 3 possible cross-section lines; [0060] FIG. 25 shows the measured dimensions on SEM micrograph for the evaluation of the profile angle of the back wall. The inlet shows a diagram of the shape at the bottom of a square cavity. The black line shows the plan in which the measurement is done; and [0061] FIG. 26 shows the measured dimensions on SEM micrograph for the photoresist end thickness, the undercut and the scallop size. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0062] FIG. 11 shows a sequence diagram in accordance with an embodiment of the present invention. After the substrate has been patterned with a photoresist mask, such as depicted in FIG. 2 or by any other technique, the sample is placed in the ICP chamber. After being clamped on the platen (or chuck) and the process conditions have been stabilized in flow and pressure, the plasma is then lit, and the sample undergoes a deposition, followed by the etching step that removes the deposition. Next, comes a high pressure etching (main etch) as in the 3-step process shown in FIG. 7 . Finally, the cycle finishes with another bombardment condition at low pressure and high platen power prior to the next cycle, making a total of four steps per cycle. These four steps are repeated until the right depth is obtained or an underneath etch stop layer is reached. [0063] FIG. 12 is a schematic representation of the steps that the sample encounters during the first cycle of the sequence shown in FIG. 11 . In the first step the polymer is deposited as explained with reference to FIG. 3 . This polymer is removed in the second step at least from the surface of the photoresist and the bottom of the opening in the photoresist layer 12 . The polymer may remain on the sidewalls, but this remaining layer is not shown in the drawings. [0064] In the third step, the high pressure etch is performed to form the first portion 16 a of the trench, and then the fourth step is performed to remove any surface roughness. FIG. 13 shows the formation of the second portion 16 b of the trench in the third step. This is formed with surface roughness 18 , which is removed in the fourth step before starting the third cycle as shown in FIG. 14 . [0065] FIGS. 13 and 14 schematize the 4-step method when using high pressure in the main etch step for subsequent cycles 2 and 3 . At the end of the high pressure main etch step in each cycle, roughness is observed as in the case of the 3-step method. The roughness removal step then smoothes the surface. Experimental Results [0066] Using a STS Pegasus silicon ICP chamber, we etched two samples: one used the prior art 3-Step Method and one used the 4-Step Method” in accordance with embodiments of the present invention. This was etched on 150 mm silicon wafers with a negative photoresist mask that exhibits square and circle features. Both show about 1000 μm of width or diameter. About 29% of the total surface is not masked on the wafer where silicon is exposed to etching. Table 4.2.1 and Table 4.2.2 show all parameters that were used for the Sample A (using the 3-Step Method) and Sample B (using the 4-Step Method) respectively. [0000] TABLE 4.2.1 Recipe parameters for a 3-Step Method: SAMPLE A High Removal Pressure Parameters Deposition Etch Step Etch step Total time (mm:ss) 19:00 Cycle time 5 s 1.5 s 7.5 s Pressure (mTorrs): 35 mTorr 20 mT 325 mT Gases (sccm): C4F8 250 sccm 0 0 O2 0 0 10 sccm SF6 0 250 sccm 1000 Generators Coil 2700 W 4800 W 4800 W 13.56 MHz (W) Generators Platen 0 170 W 50 W 13.56 KHz (W) Platen 0 0 0 Temperatures (° C.) Back side 10 10 10 cooling gas = Helium (Torrs) [0000] TABLE 4.2.2 Recipe parameters for a 4-Step Method: SAMPLE B Low pressure Removal Etch High Pressure bombardment etch Parameters Deposition Step Etch step step Total time (mm:ss) 19:00 Cycle Time 5 s 1.5 s 7.5 s 1 s Pressure (mTorrs): 35 mTorr 20 mT 325 mT 15 mT Gases (sccm): C4F8 250 sccm 0 0 0 O2 0 0 10 sccm 1 sccm SF6 0 250 sccm 1000 250 sccm Generators Coil 13.56 MHz 2700 W 4800 W 4800 W 4800 W (W) Generators Platen 13.56 KHz 0 170 W 50 W 150 W (W) Platen Temperatures (° C.) 0 0 0 0 Back side cooling gas = 10 10 10 10 Helium (Torrs) [0067] The following images ( FIG. 15 to 17 ) show Scanning Electron Microscopy (SEM) images coming from a few sites on Sample A. [0068] FIG. 15 is a SEM micrograph of a cavity on the center of the Sample A. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut. [0069] FIG. 16 is a SEM micrograph of a cavity on the top (opposite to major flat) of the Sample A. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut. [0070] FIG. 17 is a SEM micrograph of a cavity on the right hand side (considering the major flat on the bottom) of the Sample A. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut. [0071] FIGS. 18 to 20 are Scanning Electron Microscopy (SEM) images coming from a few sites on Sample B. The same sites as Sample A were observed. [0072] FIG. 18 is a SEM micrograph of a cavity on the center of the Sample B. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut. [0073] FIG. 19 is a SEM micrograph of a cavity on the top (opposite to major flat) of the Sample B. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut. [0074] FIG. 20 is a SEM micrograph of a cavity on the right hand side (considering the major flat on the bottom) of the Sample B. Top: Whole cross-section of the square cavity. Bottom left: Focus on the back wall. Bottom right: Zoom of the photoresist mask and the etch undercut. [0075] FIG. 21 shows a comparison of the wall roughness for the same site on each sample (right hand side of the wafer). One can observe that Sample A (above image) has horizontal scallops on top of the etch feature (near the surface) which degrade into a mix of vertical and horizontal lines on the bottom sidewall. The vertical lines are caused by roughness that is carried down to the bottom of the cavity. This was depicted in FIGS. 7 , 8 and 9 . The roughness is observed on the bottom of the cavity. However, the sidewall roughness is usually more inconvenient than roughness on the bottom of the cavity. Nevertheless they are created at the same time during the high pressure main etch step of each Bosch cycle. On the Sample B (bottom image) this is not seen and continuous horizontal scallops are observed down to the bottom of the sidewall. Note that the two SEM micrographs are not at the same magnifications. [0076] The above explanation demonstrates that Sample A recipe will be limited at some depth because sidewall and bottom roughness will worsen as the etch gets deeper. Sample B recipe does not show limitation yet at this depth. Furthermore, these vertical lines seen in Sample A demonstrate limitation in depth for such recipe for some commercial applications where sidewall roughness is specified tightly. This also demonstrates that this recipe has a maximum limit in depth for which it can be used. Roughness can only get worse with the same recipe and eventually, “grass” will appear if we etch further down. Sample B recipe does not show such limitations; therefore that recipe is less sensitive to generate grass. Therefore, for the same specification in roughness, the Sample B recipe will be limited at a depth that is greater than for the Sample A recipe. Without using the 4-step method in accordance with embodiments of the invention, the Sample A recipe would have to be modified in order to meet tight specification, and necessarily, the etch rate would be lowered to accommodate smoother sidewalls and smoother bottom surfaces. Either pressure, total time of a Bosch cycle, or the etch-to-deposition ratio would be reduced. Both would result in lower etch rates. [0077] FIGS. 22 and FIG. 23 are microscope images at 10×, on the roughest die on two regions for both wafer (the two worst regions). The same dice were compared on both wafers. The focus is on the bottom of the cavity. We observe that Sample B has slightly less roughness on the bottom compared to Sample A. [0078] FIG. 22 is a microscope image on the two worst dice of the wafer in term of roughness for the Sample A. Left hand side image: Top of the wafer. Right hand side: Right of the wafer. [0079] FIG. 23 is a microscope image on the two worst dice of the wafer in term of roughness for the Sample B. Left hand side image: Top of the wafer. Right hand side: Right of the wafer. [0080] Table 4.2.3 shows the results obtained for both samples. Three site were measured on each sample for all measurements: center of the wafer, top of the wafer (opposite to major flat) and on the right side of the wafer. We observed that the etch rates are similar from one to the other. However, the uniformity across the wafer is much better on Sample B. The non-uniformity across the wafer was evaluated as follows: [0000] Non-Uniformity=(Maximum depth−Minimum depth)/(2×Average depth)   {EQUATION #1} [0081] FIG. 25 shows the dimensions we measured to evaluate the profile angle. This is the standard way to measure the profile angle in the DRIE field. The Profile Angle is then obtained with the following equation: [0000] φ=90+arctan [( L 2 −L 1)/(2* D )]  {EQUATION #2} [0082] The inset of FIG. 24 depicts the shape of the bottom of the cavity for a square mask opening when the profile is re-entrant (i.e. profile angle>90°). The cleavage of such structure is difficult and the position of the cross-section line will vary from one to another. Therefore the profile angle evaluated in Table 4.2.3 is only indicative and no uniformity was evaluated. [0083] FIG. 25 shows the measured dimensions used to measure the profile angle of the back wall. The same Equation 2 was used. This measurement does not depend on the cross-section line and is therefore reproducible form one to another. This measure was used to compare objectively the two profiles. We observe that the averages are identical but that less variation is observe across the wafer for Sample B. This can be potentially explained with the fact that Sample B recipe well clears the roughness on the bottom of the cavity up to the corner of the cavity at each cycle. [0000] TABLE 4.2.3 Obtained parameters both sample Parameter Sample A Results Sample B Results Etch Rate (um/min) 24.61 um/min ± 3.4% 25.18 um/min ± 1.8% and ± uniformity across the wafer Profile angle 93.45° 93.42° Profile angle on 90.5° ± 0.25° 90.6° ± 0.08° the back wall Undercut 1.35 to 2.95 um per side 2.1 to 2.65 um per side Scallop size <1.75 um <1.75 um Selectivity to resist 163:1 112:1 [0084] FIG. 24 shows the measured dimensions on SEM micrograph for the evaluation of the profile angle. The inset shows a diagram of the shape at the bottom of a square cavity. The three lines show three possible cross-section lines. [0085] FIG. 25 shows the measured dimensions on SEM micrograph for the evaluation of the profile angle of the back wall. The inset shows a diagram of the shape at the bottom of a square cavity. The red line shows the plan in which the measurement is done. [0086] FIG. 26 shows the dimensions where we measured the photoresist end thickness, the undercut and the scallop size. The undercut is the distance between the opening of the photoresist mask and the lateral edge of the first scallop. The Sample A undercut shows less uniform undercut across the wafer. It is not sure at this point if this is due to the fourth step on the first cycle. The scallop size is the horizontal dimension of the second scallop. We measure this particular scallop because the scallops tend to diminish in size as the etch goes deeper. Therefore this scallop is assumed to be the largest on each cavity. This value is identical on both samples. This dimension mainly depend on the high pressure etch step. Since this step is identical in both recipes, it is normal to find the same result. The selectivity is defined as follow: [0000] Selectivity=(Depth of the cavity)/[(Initial Photoresist thickness)−(Photoresist end thickness)]  {EQUATION #3} [0087] In Equation 3, we used the average depth of the cavity, an initial thickness of 10±0.1 μm (guarantied specification for this photolithography manufactured mask), and the minimum end thickness found on each wafer. Therefore this selectivity is the worst case found in all measurements. The fact that Sample B has a lower selectivity was expected since more ion bombardment is used at each cycle. However, selectivity greater than 100:1 is generally considered in the industry as out standing for such etching. [0088] The above results show that the following advantages can be achieved compared to the 3-step method: [0089] Better uniformity on the etch rate [0090] Better profile uniformity [0091] Better uniformity on the undercut. [0092] No unwanted vertical roughness on the sidewalls [0093] Less roughness is observed on the bottom of the cavity [0094] For the same roughness specifications, embodiments of this invention can use higher etch rate and also can be used up to larger depths. [0095] Embodiments of the present invention when compared to the 3-step method results in a similar profile angle, a similar etch rate, the same scallop size, and a similar undercut. [0096] Embodiments of the present invention also prevent the worsening of the bottom roughness, and therefore allow the use of high pressure without its associated disadvantages. It also pushes further the theoretical limit of the maximum depth that can be achieved with the standard Bosch process.

In a method of performing an anisotropic etch on a substrate in an inductively coupled plasma etch chamber, at least three cycles of a procedure consisting essentially of the four following steps are performed: a. depositing a protective polymer on a patterned substrate; b. performing a first low pressure etch to partially remove the deposited protective polymer at a pressure less than 40 mTorr; c. performing a high pressure etch at a pressure between between 40 mT and 1000 mT to form a portion of a trench in the substrate; and d. performing a second low pressure etch at a pressure less than 40 MTorr to reduce surface roughness. This method permits the fabrication of deep trenches with reduced surface roughness.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/674,356, filed on Jul. 22, 2012, and U.S. Provisional Patent Application Ser. No. 61/674,809, filed on Jul. 23, 2012 the entire disclosures of which are incorporated by reference in their entirety. FIELD OF THE INVENTION This application relates generally to systems and methods for removing materials below the surface of the earth. More specifically, this application relates to systems and methods for removing subsurface materials without excavating the overburden using “open pit”, “floating dredge” or other conventional excavation methods. BACKGROUND TECHNOLOGY Core drilling allows sampling of subterranean materials from various depths to be obtained for many purposes. For example, drilling a core sample and testing the retrieved core helps determine what materials are present or are likely to be present in a given formation. For instance, a retrieved core sample can indicate the presence of petroleum, precious metals, sand, and other desirable materials. Accordingly, core samples can be used to determine the desirability of further exploration and/or mining in a given area. In sonic core drilling processes, variable frequency vibration is created by an oscillator. The vibration is then mechanically transferred to the drill string of the core barrel and/or casing. The vibration is transmitted in an axial direction down through the drill string to an open-faced drill bit. As a result, the drill string may be rotated and/or mechanically pushed as it is vibrated into the subsurface formation. Often, sonic core drilling processes are used to retrieve a sample of material from a desired depth below the surface of the earth. Although there are several ways to collect core samples, core barrel systems are often used for core sample retrieval. Core barrel systems include an outer tube with a coring drill bit secured to one end. The opposite end of the outer tube is often attached to a drill string that extends vertically to a sonic drill head that is often located above the surface of the earth. The core barrel systems also may include an inner polycarbonate tube located within the outer core barrel. As the drill bit cuts formations in the earth, the inner tube can be filled with a core sample. Once a desired amount of a core sample has been cut, the inner tube, core barrel, and core sample can be brought up through the drill string and retrieved at the surface. The sonic drill head may include high-speed, rotating counterbalances that produce resonant energy waves and a corresponding high-speed vibration to be transmitted through the drill string to the core barrel. As a result, the sonic drill head can vertically vibrate the core barrel. In addition, the drill head can rotate and/or push the core barrel into the subsurface formation to obtain a core sample. Once the core sample is obtained, the core barrel (containing the core sample) is retrieved by removing the entire drill string out of the borehole that has been drilled. Once retracted to the surface, the core sample may then be removed from the core barrel. In a sonic wireline drilling process, the core barrel and the casing are advanced together into the formation. The casing again has an open-faced drill bit and is advanced into the formation. However, the core barrel (inner tube) does not contain a drill bit or connect to a drill string. Instead, the core barrel mechanically latches inside of and at the bottom of the casing and advances into the formation along with the casing. When the core sample is obtained, a drill operator can retrieve the core barrel using a wireline system. Thereafter, the drill operator can remove the core sample from the core barrel at the surface, and then drop the core barrel back into the casing using the wire line system. As a result, the wireline system eliminates the time needed to trip the drill rods and drill string in and out of a borehole for retrieval of the core sample. Conventionally, upon detecting the presence of subterranean desirable materials, such as precious metals, sand and the like, an open pit mine is dug. In open pit mining, a large pit is dug and the overburden material positioned over the desirable materials is removed and hauled to a different location. However, forming an open pit mine is very time-consuming and expensive. Often an extensive dewatering system is required. There is also a large carbon footprint as millions of tons of overburden material removed from the open pit are trucked away. Further, there can be large capital costs in excavation equipment and infrastructure such as roads in order to form the open pit. Moreover, in some instances the open pit can be refilled, increasing cost as the removed overburden material is returned to the pit. Thus, there is a need in the art for systems and methods for removing desirable subsurface materials without the need to dig an open pit mine to remove the overburden waste material. The present invention fulfills these needs and provides further related advantages as described herein The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced. SUMMARY The invention relates to systems and methods for removing a desired subsurface material. In one aspect, the systems and methods for removing a desired subsurface material comprise removing subsurface materials without excavating the overburden waste material other than that excavated when forming a conventional exploratory borehole. The system for removing desired subsurface materials comprises a drilling system and a material removal system. In one aspect, the drilling system comprises a drill head assembly capable of rotating a drill string and transmitting oscillating forces to the drill string. In use, the drill head assembly can cause a drill bit attached to the drill string to form a borehole extending into a surface. The drill string can line the borehole forming an outer casing. The material removal system comprises a sonic air lift tooling system (“S3RP”) and a discharge tank. In one aspect, the sonic air lift tooling system comprises an outer tube having an outer diameter and defining an inner volume. The outer tube annulus can be in fluid communication with a source of pressurized fluid, such as air, and the like. The sonic air lift tooling system can further comprise an inner tube. In one aspect, the inner tube has an outer diameter sized so that that at least a portion of the inner tube can be positioned in the inner volume of the outer tube. In another aspect, the outer diameter of the inner tube can be sized so that an annular void is defined between the outer tube and the outer diameter of the inner tube. In a further aspect, a distal end of the inner tube can define at least one opening such that an interior conduit of the inner tube is in fluid communication with the annular void outside of the distal end of the inner tube. A proximal end of the inner tube can be in fluid communication with a discharge tank such that the interior conduit of the inner tube is in fluid communication with the discharge tank. In use, the pressurized fluid, such as compressed air, and the like can be injected through the outlet tube inlet and into the annular void between the outer tube and the inner tube. The pressurized fluid can be urged towards the distal end of the inner tube. Upon reaching the distal end of the inner tube, in one aspect, the pressurized fluid can pass from the annular void through the opening to the interior conduit of the inner tube. Because the desired subsurface material can be a flowing material, such as, for example and without limitation, sand, the desired subsurface material can become entrained in the fluid in the interior conduit of the tube. In the interior conduit of the tube, the fluid and the desired subsurface material entrained therein can be “lifted” or otherwise urged to the discharge tank. In other aspects, varying combinations of pressurized fluids and flow directions can be utilized. However, in each aspect, the desired material can be removed from below the surface using the same borehole that was formed during exploratory drilling without the need for additional overburden material removal. For purposes of summarizing, some aspects, advantages and features of a few of the embodiments of the invention have been described in this summary. Some embodiments of the invention may include some or all of these summarized aspects, advantages and features. However, not necessarily all of (or any of) these summarized aspects, advantages or features will be embodied in any particular embodiment of the invention. Thus, none of these summarized aspects, advantages and features are essential. Some of these summarized aspects, advantages and features and other aspects, advantages and features may become more fully apparent from the following detailed description and the appended claims. DETAILED DESCRIPTION OF THE DRAWINGS The appended drawings contain figures of preferred embodiments to further clarify the above and other aspects, advantages and features. It will be appreciated that these drawings depict only preferred embodiments of the invention and are not intended to limit its scope. These preferred embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1 is an elevational view of a drilling system, according to one example. FIG. 2A is a side elevational view of a sonic air lift tooling system of a system for sonic subsurface material removal, according to one aspect. FIG. 2B is a cross-sectional view of the sonic air lift tooling system of FIG. 2A taken along line B-B of FIG. 2A . FIG. 2C is a perspective view of the sonic air lift tooling system of FIG. 2A . FIG. 3 is a schematic diagram illustrating a system and method for sonic subsurface material removal, according to one aspect. FIG. 4 is schematic diagram illustrating a system and method for sonic subsurface material removal, according to one aspect. FIG. 5 is an elevational view of an exemplary system and method for sonic subsurface material removal, according to one aspect. FIG. 6 is an elevational view of a second exemplary system and method for sonic subsurface material removal, according to one aspect. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The present invention can be understood more readily by reference to the following detailed description, examples, drawings, and claims, and their previous and following description. However, before the present devices, systems, and/or methods are disclosed and described, it is to be understood that this invention is not limited to the specific devices, systems, and/or methods disclosed unless otherwise specified, as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. The following description of the invention is provided as an enabling teaching of the invention in its best, currently known embodiment. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the invention described herein, while still obtaining the beneficial results of the present invention. It will also be apparent that some of the desired benefits of the present invention can be obtained by selecting some of the features of the present invention without utilizing other features. Accordingly, those who work in the art will recognize that many modifications and adaptations to the present invention are possible and can even be desirable in certain circumstances and are a part of the present invention. Thus, the following description is provided as illustrative of the principles of the present invention and not in limitation thereof. As used throughout, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a pipe” can include two or more such pipes unless the context indicates otherwise. Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. As used herein, the terms “optional” or “optionally” mean that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not. In one aspect, the system for sonic subsurface material removal can comprise a drilling system 100 and a material removal system 200 . FIG. 1 illustrates a drilling system 100 for drilling into the surface 105 of the earth that comprises a drill head assembly 110 . The drill head assembly can be coupled to a mast 120 that in turn is coupled to a drill rig 130 . The drill head assembly 110 is configured to have a drill rod 140 coupled thereto to form a drill string 150 . As can be appreciated, any number of drill rods can be added so that the drill string is the desired length. In turn, the drill string 150 can be coupled to a drill bit 160 configured to interface with the material to be drilled, such as a formation 170 . In at least one example, the drill head assembly 110 is configured to rotate the drill string 150 . In particular, the rotational rate of the drill string 150 can be varied as desired during the drilling process. Further, the drill head assembly 110 can be configured to translate relative to the mast 120 to apply an axial force to the drill head assembly 110 to urge the drill bit 160 into the formation 170 during a drilling process. The drill head assembly 110 can also generate oscillating forces that are transmitted to the drill rod 140 . These forces are then transmitted from the drill rod 140 through the drill string 150 to the drill bit 160 . Upon insertion of a drill rod 140 into a borehole 180 , the drill rod can form an outer casing 190 . As a result, a drill operator can use the outer casing to maintain the borehole. Once an outer casing is in place, the drill operator can trip a core barrel and its corresponding drill string into the borehole through an interior volume 195 of the outer casing and advance the core barrel ahead of the casing to retrieve a core sample. In another aspect, in a wireline drilling processes, a drill operator can simultaneously advance the casing and the core barrel together through a formation. Using a wireline process, the drill operator can trip the inner core barrel in and out of the drill string to obtain core samples from the core barrel. In one aspect, the material removal system 200 of the system for sonic subsurface material removal comprises at least one of a sonic air lift tooling system 210 , and a discharge tank 230 . With reference to FIGS. 2A , 2 B and 2 C, the sonic air lift tooling system 210 can, in one aspect, comprise an outer tube 235 and an inner tube 240 . The outer tube can be sized such that at least a portion of the outer tube can be coupled to the outer casing 190 in the borehole. For example, at least a portion of the outer tube 235 can have an outer diameter 245 of about 4 inches, about 5 inches, about 6 inches, about 7 inches, about 8 inches, or greater than about 8 inches. In another aspect, a distal end 250 of the outer tube can be threaded to engage complementary threads on a portion of the outer casing. In a further aspect, an internal diameter of the outer tube 235 can be substantially the same as an internal diameter of the outer casing, and/or the external diameter of the outer tube can be substantially the same as the external diameter of the outer casing. In one aspect, a proximal end 255 of the outer tube 235 can be configured to couple to a discharge head 260 . In another aspect, an outer tube inlet 265 can be defined in a portion of the outer tube 235 of the sonic air lift tooling system 210 . In this aspect, the outer tube inlet can be a boss configured to place an inner volume 270 of the outer tube in fluid communication with a source of pressurized fluid, such as air, and the like. The inner tube 240 of the sonic air lift tooling system 210 can be sized such that at least a portion of the inner tube can be positioned in the inner volume 270 of the outer tube 235 . For example, at least a portion of the inner tube can have an outer diameter 275 of less than about 4 inches, about 4 inches, about 5 inches, about 6 inches, about 7 inches, or greater than about 7 inches. In one aspect, the outer diameter of the inner tube 240 can be sized so that, when the inner tube is positioned in the inner volume 270 of the outer tube 235 , an annular void 277 is defined between the outer tube and the inner tube 240 . In another aspect, a proximal end 280 of the inner tube can be configured to couple to the discharge head 260 such that an interior conduit 285 of the inner tube is in fluid communication with an inner conduit 290 of the discharge head. A distal end 295 of the inner tube 240 can be open such that a fluid can enter or exit the interior conduit of the inner tube. In one aspect, the distal end of the inner tube can define a plurality of holes 300 . In this aspect, at least one hole of the plurality of holes can be angled from the center of the inner tube upwardly towards the outer diameter 275 of the inner tube 240 . That is, the longitudinal axis L H of the at least one hole can be at an acute angle relative to the longitudinal axis L I of the inner tube. For example, an angle formed between the longitudinal axis L I of the inner tube and the longitudinal axis L H of the at least one hole 300 can be about 10 degrees, about 20 degrees, about 30 degrees, about 40 degrees, about 45 degrees, about 50 degrees, about 60 degrees, about 70 degrees, about 80 degrees, or about 90 degrees. In still another aspect, each hole of the plurality of holes can have a hole diameter of less than 0.25 inches, about 0.25 inches, about 0.50 inches, about 0.75 inches, about 1.0 inches, or greater than about 1 inch. A central portion 305 of the inner tube 240 can connect the distal end 295 of the inner tube to the proximal end 280 of the inner tube. As can be appreciated, the central portion can have a length configured so that the proximal end of the inner tube 240 is positioned above the surface 105 of the formation 170 and the distal end of the inner tube is positioned in the borehole 180 at a desired depth, described more fully below. For example, the central portion 305 of the inner tube can comprise a plurality of inner tube sections that can be coupled together at the surface to form an inner tube having the desired length. In one aspect, the discharge head 260 can be sized and configured so that material removed from the borehole 180 through the sonic air lift tooling system 210 can be redirected to the discharge tank 230 . For example, material removed from the borehole can be urged through the interior conduit 285 of the inner tube, through the inner conduit 290 of the discharge head and to the discharge tank. In one aspect, at least a portion of the discharge head can have a diameter of about 3 inches, about 4 inches, about 5 inches, about 6 inches, about 7 inches, or greater than about 7 inches. It is contemplated that a variety of flanges, gaskets, fasteners, adapters and the like can be provided to couple portions of the sonic air lift tooling system and/or the discharge head together as necessary. The discharge tank 230 , illustrated in FIGS. 5 and 6 , can be a tank configured to hold a liquid, such as water. In one aspect, the discharge tank can comprise a recirculation baffle plate 232 . The recirculation baffle plate can allow water to flow over the plate while restricting the flow of solids, such as a desired material 340 , from passing over the plate. Thus, the recirculation baffle plate 232 can at least partially separate the desired material from water or other fluid it can become mixed with. In another aspect, the discharge tank can further comprise a recirculation line 234 . In this aspect, the recirculation line can place the discharge tank in fluid communication with the outer tube inlet 265 of the sonic air lift tooling system 210 so that water from the discharge tank can be selectively directed to the inner volume 270 of the outer tube 235 . Optionally, the discharge tank can further comprise at least one of a cyclone 231 and a backhoe 233 , as known in the art, configured to further separate and/or remove the desired material from the fluid in the discharge tank. It is of course contemplated that the discharge tank 230 can further comprise at least one overflow drain, flow meter, valve and the like as necessary to process water discharged from and/or injected into the material removal system 200 . Referring now to FIGS. 3 and 4 , in order to remove subsurface materials using sonic drilling techniques, a borehole 180 can be formed as in conventional sonic drilling. For example, a target drilling zone can be identified through obtaining sonic samples of geological formations 170 . In one aspect, the outer casing 190 and/or the core barrel can be advanced through any overburden material 335 and the desired material 340 until a lower layer 345 of the desired material is reached. As can be appreciated, sonic technology allows for the installation of the outer casing to the lower layer of the desired geological formation without the use of drilling fluids or disturbance to the target geological formation around the borehole (i.e., the area around the borehole can remain substantially intact until the mining process commences). Further, sonic drilling technology can accurately identify the bottom of the desired geological formation so that the outer casing 190 can be properly positioned. Upon locating the lower layer 345 of the desired material 340 , a portion of the outer casing 190 can be retracted from the borehole 180 . In one aspect, the outer casing can be retracted from the borehole a predetermined distance, such 1 foot, 2 feet, 3 feet and the like. In another aspect, the outer casing 190 can be retracted from the borehole until a distal end 320 of the outer casing is positioned a predetermined distance from the lower layer 345 and/or an upper layer 350 of the desired material. For example, the distal end of the outer casing can be positioned just below the upper layer of the desired material. In still another aspect, the distal end 320 of the outer casing can be positioned at any location between the upper and lower layers of the desired material. If the desired material 340 is a flowing material, such as, for example and without limitation, quartz or sand containing ore, upon retraction of the outer casing 190 the predetermined distance, the desired material can at least partially flow into the open borehole 180 . After the desired material has been located using the sonic drilling system 100 , at least a portion of the sonic drilling system can be removed and replaced with the material removal system 200 . Thus, at least a portion of the material removal system can be inserted into the same borehole 180 that was drilled to identify the location of the desired material 340 . ( FIG. 4 illustrates separate boreholes for clarity). In one aspect, the outer tube 235 of the sonic air lift tooling system 210 can be coupled to an upper portion 355 of the outer casing 190 . After placing the distal end 320 of the outer casing in the predetermined position relative to the lower layer 345 and/or the upper layer 350 of the desired material 340 , the desired material can be removed from the borehole 180 using a plurality of removal methods, such as, for example and without limitation, a direct reverse lift method 420 , and a flooded reverse lift method 430 , illustrated in FIGS. 5-6 respectively. As illustrated in FIG. 5 , the direct reverse lift method 420 comprises injecting a pressurized fluid, such as air, water and the like through the outer tube inlet 265 of the outer tube 235 . For example, a compressor 405 can urge pressurized air from above the surface 105 of the formation 170 through the annular void 277 defined between the outer tube/outer casing 190 and the inner tube 240 so that the pressurized fluid travels around the distal end 295 of the inner tube. Upon reaching the distal end of the inner tube, at least a portion of the pressurized fluid can pass through at least one hole 300 of the plurality of holes of the inner tube. As the distal end 320 of the outer casing 190 is typically below the water line 407 (i.e., at least portions of the borehole 180 and the interior conduit 285 of the inner tube 240 are filled with ground water), the pressurized fluid can bubble up through the ground water towards the surface. In one aspect, portions of the desired material 340 , such as for example and without limitation, sand, can become entrained in the pressurized fluid as it bubbles up through the interior conduit 285 of the inner tube and can be carried towards the surface 105 . Upon reaching the proximal end 280 of the inner tube, the portions of the desired material can be urged through the discharge head 260 to the discharge tank 230 for collection. The flooded reverse lift method 430 comprises injecting a pressurized first fluid, such as air and the like through the outer tube inlet 265 of the outer tube 235 . For example, a compressor 405 can urge pressurized air from above the surface 105 of the formation 170 through the annular void 277 defined between the outer tube/outer casing 190 and the inner tube 240 . A second fluid, for example and without limitation, water, can also be injected into the outer casing so that the annular void defined between the inner tube and the outer casing is at least partially filled with a combination of the first and second fluids. In one aspect, water injected into the outer tube 235 can be water recycled from the discharge tank 230 . The pressurized first fluid can travel down the annular void towards the distal end 295 of the inner tube. Upon reaching the distal end of the inner tube, at least a portion of the first pressurized fluid can pass through at least one hole 300 of the plurality of holes of the inner tube. As the distal end of the inner tube 240 is below the water line 407 (i.e., at least portions of the borehole 180 and the interior conduit 285 of the inner tube can be filled with ground water and/or the second fluid), the pressurized first fluid can bubble up through the water in the inner tube towards the surface 105 . In one aspect, portions of the desired material 340 , such as for example and without limitation, sand, can become entrained in the first fluid as it bubbles up through the interior conduit 285 of the inner tube and can be carried towards the surface. Upon reaching the proximal end 280 of the inner tube, the portions of the desired material can be urged through the discharge head 260 to the discharge tank 230 for collection. Regardless of the lifting method used, if at any time the desired material 340 is no longer being brought to the surface 105 at a desired rate, in one aspect, the distal end 320 of the outer casing 190 can be adjusted to a different predetermined from the lower layer 345 and/or an upper layer 350 of the desired material. For example, if a low level of desired material is being extracted from the borehole 180 , the outer casing can be lowered so that the distal end of the outer casing is adjusted to a different predetermined distance from the lower layer of the desired material 340 . The methods and systems described above require no particular component or function. Thus, any described component or function—despite its advantages—is optional. Also, some or all of the described components and functions described above may be used in connection with any number of other suitable components and functions. Although several embodiments of the invention have been disclosed in the foregoing specification, it is understood by those skilled in the art that many modifications and other embodiments of the invention will come to mind to which the invention pertains, having the benefit of the teaching presented in the foregoing description and associated drawings. It is thus understood that the invention is not limited to the specific embodiments disclosed hereinabove, and that many modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although specific terms are employed herein, as well as in the claims which follow, they are used only in a generic and descriptive sense, and not for the purposes of limiting the described invention, nor the claims which follow.

A system for removing desired subsurface materials. A drilling system has a sonic drill head assembly capable of rotating a drill string and transmitting oscillating forces to the drill string. A material removal system comprises an outer tube attachable to the drill string. An inner tube has an outer diameter sized so that that at least a portion of the inner tube is positionable in an inner volume of the outer tube with an annular void defined between the outer tube and the inner tube. A distal end of the inner tube defines at least one opening such that an interior conduit of the inner tube is in fluid communication with the annular void outside of the distal end of the inner tube. Pressurized fluid can be urged from the annular void through the opening to the interior conduit, entraining the desired subsurface materials therein for removal to a discharge tank.

BACKGROUND OF THE INVENTION [0001] The present invention relates to a video signal transmitting apparatus, such as digital broadcast transmission equipment, VTRs and DVD players, and to a video signal receiving apparatus, such as television receivers or personal computer displays, VTRs and digital broadcast receiving terminals. [0002] For broadcast of high quality image content by taking advantage of the widespread use of the digital broadcast service since 1998, there is a recognition that measures need to be taken to ensure that the broadcast content cannot be copied easily. To meet this requirement, a system has been proposed in which the content to be broadcast is encrypted by an apparatus on the transmitting side and the broadcast content is decrypted by an apparatus on the receiving side. In this system, when a receiving apparatus used has no key information for decryption, the decryption processing cannot be performed and thus the content not displayed. The system can also prevent the broadcast content from being copied, as it otherwise can be through connecting a VTR to an apparatus on the transmitting side. There is a growing consensus that, from the standpoint of copyright protection of the content, some increase in cost may be tolerated. SUMMARY OF THE INVENTION [0003] In a system that uses a personal computer as an apparatus on the transmitting side and an analog display as an apparatus on the receiving side, digital R, G, B output signals of a graphic chip in the personal computer are read at a generation timing of a clock synchronization signal and then entered into three digital-analog converters (DACs) and output along with the synchronization signal to an output connector. The analog R, G, B signals entered from an input connector of the display are adjusted in contrast and black level by a preamplifier before being displayed on the analog display device. The synchronization signal is used to synchronize the display device. [0004] In an example case that uses this interface in driving a digital display such as a liquid crystal display, analog R, G, B signals entered from the input connector are sampled by analog-digital converters (ADCs) at a timing of a clock generated from the synchronization signal by a clock regenerator and are displayed on the display device by driving it. In this system, because the output clock of the clock regenerator does not precisely match the clock of the original clock generator, a display quality of the video is not satisfactory. To solve this problem, a device for automating a clock phase adjustment is used. [0005] As a fundamental solution to this problem a digital interface has been proposed and used. In the transmitting apparatus, the digital R, G, B signals are supplied to a data converter along with the clock and synchronization signals. The data converter converts these signals into a form of digital signals that is not easily influenced by the transmission path between the input and output connectors. The converted signals are sent to the output connector. A DCI (Display Control Information) block has a function of transmitting, as a control signal, display control information used to perform the same power saving controls on a display (e.g., control of such functions as video mute and sleep mode so called “DPMS” (Display Power Management System)) that have been conducted in a conventional analog interface by detecting the presence or absence of a synchronization signal. In a digital display, a digital data signal is supplied to the data converter which in turn produces R, G, B signals of digital base band and synchronization signals. The video signals are displayed on the display device by driving it. At the same time, a DCI signal supplied from the connector is also entered into the display device. In this system, the digital R, G, B signals are entered into the display device without their quality being degraded, so that a high quality displaying of video signals can be realized. example data conversion scheme is a TMDS (Transition Minimized Differential Signaling) which is a serial transmission method. [0006] In a case where a digital interface is used and a connected apparatus on the receiving side is an analog display, the output signal of the data converter is entered into the DAC where it is converted into an analog signal before being supplied to the preamplifier and the display device. Hence, the apparatus on the receiving side requires the data converter and DAC, increasing the cost, which offsets the advantages of the analog display and thus hinders a widespread use of the digital interface. [0007] It is true that the conventional method can provide the intended function of “preventing the copying of content.” But the mainstream receiving apparatus is still an analog display of CRT type, such as television receivers. This raises the following problems. [0008] Problem (1): The preferred video signals to be transmitted are luminance and color difference signals such as Y, Pb and Pr rather than R, G, B primary color signals. To meet this requirement it is preferred that the conversion from the primary signals into the luminance/color difference signals be performed on the transmitting side and information defining the conversion be sent out so that, when the luminance/color difference signal processing is performed on the receiving side, the conversion defining information can be used. However, no provision is made for transmitting the conversion defining information. [0009] Problem (2): Similarly, no means is provided for transmitting an aspect ratio of video signals of the broadcast content. [0010] Problem (3): The use of a DCI control line to realize the means for solving the above problems (1) and (2) increases cost. It is therefore necessary to enable even displays without the DCI control line to display the video normally. [0011] Problem (4): When a receiving apparatus (display) with no decryption key information is blacked out, the user may misunderstand that the apparatus has failed. It is therefore necessary to display some image even when the display does not have the decryption key information, thereby preventing the user from mistaking the failure to display the video correctly for a display failure. [0012] For each of the problems (1) to (4) described above, the present invention provides the following solutions. [0013] The problem (1) is solved by providing the transmitting apparatus with a unit which transmits colorimetry information, used for determining the coefficient of the addition processing of the matrix circuit in the display, along with composite video information (information including a digital video signal of luminance/color difference type, and a clock signal and horizontal/vertical synchronization signals in synchronism with the luminance/color difference type digital video signal). On the receiving side, the addition processing coefficient in the matrix circuit is determined based on the colorimetry information. [0014] As for the problem (2), an aspect ratio information transmission means for transmitting information on the aspect ratio of the digital video signal included in the composite video information is provided in the transmitting apparatus. On the receiving side, the predetermined aspect ratio conversion processing is performed on the received video signals according to the aspect ratio information received. [0015] As for the problem (3), a synchronization frequency detecting means for determining a frequency from the horizontal and vertical synchronization signals included in the composite video information is provided in the display. According to the detecting result produced by the synchronization frequency detecting means, a default value of at least one of the two data, the colorimetry value for determining the addition processing coefficient in the matrix circuit and the video aspect ratio, is set. [0016] As to the problem (4), the transmitting apparatus is enabled to communicate hi-directionally with the display and to receive from the display at least first display information indicating the presence or absence of decryption key information used to perform decryption processing on the encrypted composite video information. Further, the transmitting apparatus is provided with a decision means to decide, based on the first display information received from the display, whether or not the display has the decryption key information. When the decision means decides that the display does not have the decryption key information, the clock signal and the horizontal and vertical synchronization signals are set to predetermined frequencies and the composite video information is transmitted without being subjected to the decryption processing. As a result, when the decryption key information is not authenticated, a low-resolution video signal can be displayed to prevent the user from mistaking a blackout for a receiver failure. [0017] Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0018] These and other features, objects and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings wherein: [0019] FIG. 1 is a configuration block diagram of a first embodiment of the present invention; [0020] FIG. 2 is a configuration block diagram of a second embodiment of the present invention; [0021] FIG. 3 is a configuration block diagram of a third embodiment of the present invention; and [0022] FIG. 4 is a configuration block diagram of a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS [0023] While we will show and describe several embodiments in accordance with our invention, it should be understood that disclosed embodiments are susceptible of changes and modifications without departing from the scope of the invention. Therefore, we do not intend to be bound by the details shown and described herein but intend to cover all such changes and modifications as fall within the scope of the appended claims. [0024] Now, the embodiments of the present invention will be described by referring to the accompanying drawings. FIG. 1 is an essential-part block diagram of a video transmitting apparatus and a video receiving apparatus according to a first embodiment of the invention. In FIG. 1 , a video transmitting apparatus 100 comprises a clock/synchronization signal generator 101 , a graphic chip 102 , a data conversion and encryption processing block 103 , a DCI signal processing block 104 , an encryption key information block 105 , an output connector 106 , and an aspect ratio information and colorimetry information transmission block 107 . A video receiving apparatus 110 comprises an input connector 111 , a data conversion and decryption block 112 , a decryption key information block 113 , DACs 114 - 116 , a luminance/color difference signal processing preamplifier 117 , and an analog signal display device 118 . In the video transmitting apparatus 100 , the digital luminance/color difference signals Y, Ph, Pr are read out from the graphic chip 102 according to the timing of the clock/synchronization signal generator 101 and input to the data conversion and encryption processing block 103 . Here, the data conversion and encryption processing block 103 performs data conversion processing and also encryption processing by using the encryption key information of the encryption key information block 105 , and the processed data is transmitted as composite video information by the output connector 106 . At the same time, aspect ratio information and colorimetry information on the video signal of the graphic chip 102 are also superimposed on the luminance/color difference signals and the synchronization signal, and then subjected to the data conversion processing before being transmitted by the output connector 106 . A DCI signal directly sent out from the block 104 through the output connector 106 . [0025] In the video receiving apparatus 110 , the block 112 performs decryption processing and data conversion processing on the received data by using the decryption key information from the decryption key information block 113 and outputs the luminance/color difference signals to the DACs 114 - 116 and the synchronization signal to the display device 118 . Here, if a receiving apparatus that has no key information for decryption is connected, the decryption processing cannot be performed and thus the video information cannot be displayed. The output signals of the DACs 114 - 116 are input to the preamplifier 117 which performs contrast processing, black level correction processing and image quality correction processing on the luminance signal and also hue and color saturation adjustments on the color difference signal. After having been subjected to these processing, the luminance and color difference signals are summed up by a matrix circuit (not shown) in the preamplifier 117 . At this time, the addition coefficient is determined by the colorimetry information which is input through a signal line 119 separately from the luminance/color difference signals and the synchronization signal. The signals, after having undergone the matrix processing, are input to the display device 118 that displays the video signal. When the video signal is found to be, for example, a wide video (16:9) by detecting the display aspect information that is output from the block 112 through the signal line 119 , and if the display device 118 has an aspect ratio of 4:3, then the block 117 performs signal processing such as vertically compressing the video. Conversely, when the aspect information represents a standard video (4:3) and if the display device 118 has an aspect ratio of 16:9, the block 117 performs signal processing such as horizontally compressing the video. The aspect ratio adjustment may also be done by deflection processing rather than performing the vertical or horizontal compression by the block 117 . [0026] As described above, the present invention can realize the transmitting apparatus and the receiving apparatus which comprise a transmission system capable of protecting the broadcast content by encryption and decryption functions using key information and a digital interface having an excellent compatibility with a television circuit realized by the transmission of luminance/color difference signals and signal aspect information. [0027] FIG. 2 shows a second embodiment of the invention, in which function blocks identical with those of the first embodiment are assigned like reference numerals. While in the first embodiment the signals from the aspect/colorimetry information transmission block 107 are entered into the data conversion/encryption processing block 103 , this embodiment superimposes them over the DCI signal in the DCI signal processing block 104 . The signal from the DCI block 104 is transmitted through the input/output connectors 106 , 111 to the display device 118 of the receiving apparatus 110 . It is also input to an aspect/colorimetry information separation block 120 . According to the output signal from the block 120 , the preamplifier 117 controls the matrix processing of the matrix circuit and the aspect conversion processing and produces the similar effects to those of the first embodiment. [0028] FIG. 3 shows a third embodiment of the invention, in which function blocks identical with those of the first and second embodiments are assigned like reference numerals. In the first and second embodiments, the signals of the aspect/colorimetry information block 107 are entered into the data conversion/encryption processing block 103 or into the DCI processing block 104 . The third embodiment can handle both of the signal transmissions and, when there is neither of the signal transmissions, allows the receiving apparatus to deal with the situation. [0029] A receiving apparatus 122 has added to the configuration of the first embodiment an aspect/colorimetry information separation block 120 , a H/V synchronization frequency detection block 123 , and an aspect/colorimetry decision block 124 . The operation and function of the block 120 are as described in the second embodiment, and the information obtained from the signal line 119 is also as described in the first embodiment. The function of the block 123 is to detect the frequency of the synchronization signal and to output detection results, for example, in the following five conditions. [0030] (1) When fH=15.75kHz and fV=60 (or 59.94) Hz, video aspect=4:3 and colorimetry=SMPTE170M. [0031] (2) When fH=31.5 kHz and efv=60 (or 59.94) Hz, video aspect=4:3 and colorimetry=SMPTE293M. [0032] (3) When fH=33.75 kHz and fV=60 (or 59.94) Hz, video aspect=16:9 and colorimetry=SMPTE240M. [0033] (4) When fH=45 kHz and fV=60 (or 59.94) Hz, video aspect=16:9 and colorimetry=SMPTE296M. [0034] (5) In cases other than the above, video aspect=16:9 and colorimetry=SMPTE240M. (fH and fV are horizontal and vertical synchronization frequencies, and SMPTE is the name of the standardization committee on video signal in the U.S.A.) [0035] When the block 124 cannot obtain the information from the block 120 or from the signal line 119 , it selects one of (1) to (5) according to the synchronization signal frequency detection result from the block 123 , determines the aspect and colorimetry and thereby controls the preamplifier 117 . In this embodiment, even when none of the colorimetry information and the aspect information is transmitted, the effects similar to those of the first embodiment can be obtained. [0036] FIG. 4 shows a fourth embodiment of the invention, in which function blocks identical with those of the first and second embodiments are assigned like reference numerals. In the first and second embodiment, the aspect and colorimetry information is supplied to either the block 103 or the DCI processing block 104 . In this embodiment, it is superimposed on both blocks. This embodiment adds to the transmitting apparatus 130 a connection detection block 133 , a synchronization setting signal line 135 , a SW select control line 134 , a SW 132 , and a connected apparatus information block 136 . This embodiment can realize two functions, (a) preventing a blackout of the receiving apparatus and (b) preventing the condition of the connected apparatus from being misinterpreted. The function (a) will be explained in the following. The output signal of the block 107 is entered to the blocks 104 , 103 . If the receiving apparatus matches the signal information from the DCI line or the signal information from the data conversion output, the aspect and colorimetry control can be made. [0037] In this embodiment, the signal line connecting the receiving apparatus and the transmitting apparatus is bi-directional and the transmitting apparatus has a function of authenticating the key information in the receiving apparatus. When the key authentication is not performed or failed, the connection detection block. 133 performs control through the signal line 135 to change the synchronization setting of the block 131 to “fH=15.75 kHz, fV=60 Hz and interlace ratio of 1:2” or “fH=31.5 kHz and fV=60 Hz.” As a result, the output signal Y, Pb, Pr of the graphic chip 102 is set to the so-called “NTSC grade” or “VGA grade” and, based on this signal, the block 103 performs only the data conversion (not decryption), allowing the receiving apparatus to display the video received through the connector 106 at a low resolution. That is, when the key authentication is performed, the video signal can be displayed at a high resolution; and when the key authentication is not performed, the video signal is displayed at a low resolution. In this way, a blackout can be prevented. [0038] Next, the function (b) will be explained. The connected apparatus information block 136 stores information with which to check whether the receiving apparatus is capable of handling the luminance/color difference signal input such as Y, Pb and Pr. This information is input together with the information from the block 107 to the blocks 104 , 103 and is superimposed on both of the signal information from the DCI line and the signal information from the data conversion output. In this embodiment, since the signal line connecting the receiving apparatus with the transmitting apparatus is bi-directional and the DCI signal line is also bi-directional information. indicating that “the receiving apparatus is capable of handling the luminance/color difference signal input” can be returned to the transmitting apparatus. For example, it is preferred that a command be defined in a command expansion area of the DCI2AB and standardized. When a command indicating “capable of handling the luminance/color difference signal input” is returned, the video signal continues to be transmitted. When a command indicating “not capable of handling the luminance/color difference signal input” is returned, the connection detection block 133 performs control to switch the signal input of the SW 132 from Y/Pb/Pr to R/G/B. As a result, the block 103 performs data conversion on the R, G, B primary color signal as the video signal and encrypts it before transmitting it to the connector 106 . At the same time, the block 107 also outputs the colorimetry information representing the “primary color signal.” Therefore, if the receiving apparatus is a personal computer display which accepts only the RGB input, it is possible, as long as the connector 106 of the same standard is used, to prevent the video signal from being displayed in wrong colors, thus allowing a variety of connecting configurations to be used. This system thus can reproduce a video with high quality and high resolution while at the same time realizing the copyright protection which allows only the users authorized by the key information to retrieve that content. This system can also provide a transmitting apparatus, display and an interface harmonized with a television-based rationalized circuit. [0039] The display taken as an example of the receiving apparatus with an input connector in this embodiment includes a television, a front data projector and a personal computer monitor and also a recording device such as VTR. In other words, this function can be realized with any apparatus capable of receiving a digitized video signal (including digital broadcast signal) and can be implemented in any form not limited to this embodiment. 1 - 12 . (canceled)

An interface is realized that can prevent video signals from being copied easily and which uses a luminance/color difference signal transmission scheme with an excellent harmony with a television circuit. In a video transmission using a digital interface, colorimetry information for defining the conversion from the luminance/color difference signal into a primary color signal and video aspect ratio information are transmitted along with the luminance/color difference type video signal. This allows reproduction of video with high quality and high resolution and also realizes a copyright protection which allows only the users authorized by key information to use the content of the video. With this transmission scheme, it is possible to provide a transmitting apparatus, a receiving apparatus and an interface which highly harmonize with a rationalized television-based circuit.

FIELD OF THE INVENTION The present invention relates to a bearing that fits and is removable and/or securable to a wall of a reproduction apparatus. The features of the present invention provide in embodiments a mounting system advantageously for use in most any apparatus which requires bearings, for example, electrophotographic printing machines. BACKGROUND OF THE INVENTION Electrophotographic marking is a well-known, commonly used method of copying or printing documents. Electrophotographic marking is performed by exposing a charged photoreceptor with a light image representation of a desired document. The photoreceptor is discharged in response to that light image, creating an electrostatic latent image of the desired document on the photoreceptor's surface. Toner particles are then deposited onto that latent image, forming a toner image, which is then transferred onto a substrate, such as a sheet of paper. The transferred toner image is then fused to the substrate, usually using heat and/or pressure, thereby creating a permanent record of the original representation. The surface of the photoreceptor is then cleaned of residual developing material and recharged in preparation for the production of other images. Other marking technologies, for example, electrostatographic marking and ionography are also well-known. An electrophotographic marking machine generally includes bearings for supporting and connecting parts, for example, a shaft. While such bearings are generally successful, fastening of the bearing to a member may be time consuming and costly. Bearings may add to the cost of the machine. Further, the bearing may wear or fail and cause inefficient operation of the machine. In addition, manufacturing time is required to install the bearings and to connect the components to the bearings during assembly of the machine. Also, to conserve natural resources and provide for a machine with improved features and more reliable newer technology, machinery is often remanufactured and disassembled. Furthermore, the removal of the bearings represents a cost associated with remanufacturing of the machines. The time required to remove bearings may be a significant remanufacturing cost factor. Components have typically been joined together with the use of bearings in the form of welding, rivets or screws. Rivets require the use of special machinery to assemble, may become loose and rattle during use and are difficult and expensive to remove for remanufacturing. Screws have disadvantages in that they require a substantial amount of assembly time, may become loose during use, and may become very time consuming to remove. Therefore, a bearing that may be easily manufactured and that is removeably securable to a surface for use with other parts would be beneficial. Moreover, it has been increasingly important to develop lighter materials for the framework of the machines. Accordingly, many modem machines utilize a fabricated sheet metal or plastic frame resulting in relatively thin walled support structures. Throughout a typical printing machine, there are many shafts utilized to support idler rollers, drive rollers. It is therefore desirable to provide a bearing which can be utilized in a wall while still providing generally high durability. Reference is made to the following United States patents relating to reproduction machines and components such as bearings briefly summarized as follows: U.S. Pat. No. 6,024,497 relates to a bushing mountable in a housing for supporting a rotating member and for providing a bias force to the rotating member. The bushing includes a body defining an aperture therein and a mounting member for mounting the bushing to the housing. The bushing also includes a biasing member operably associated with said body and said mounting member. U.S. Pat. No. 5,632,684 relates to a shaft assembly and method of forming a shaft assembly having an elongated hollow shaft with a stepped portion on the surface of the shaft. The stepped portion of the shaft surface is formed of two straight edge sections joined by an inclined section. A gear having a corresponding straight/inclined edge configuration engages the shaft and contacts the shaft only on the corresponding straight edge portions. U.S. Pat. No. 5,538,475 relates to a shaft assembly comprising an elongated member having at least a portion which is hollow, tubular, shell like having an inside surface defining a shaft core and an outside surface defining a shaft functional surface, the shaft core being filled with a hardened, moldable material, and the shaft functional surface having at least one functional feature thereon, which is of hardened, moldable material integrally molded with the hardened, moldable material in the shaft core. U.S. Pat. No. 5,511,885 relates to a plain flanged bearing or bushing for supporting a rotating shaft in a thin walled frame of an electrophotographic printing machine. The composite bearing has a flanged end and is adapted to be inserted in an opening in a thin walled support member until the flange abuts the surface of the wall. A protruding tab formed by displacing a small portion of the flange extends in an axial direction along the bearing and cooperates with a corresponding opening in the wall to prevent rotation of the bearing. A friction push nut or snap ring is attached to the bearing on the side of the wall opposite the flange. The protruding tab prevents the bearing from rotating about an axis which can cause the bearing to be worn on the exterior surface by rotational contact with the thin wall. A shaft to support idler rolls or other rotating elements is inserted in an inner bore of the bearing and is rotatably supported thereby. U.S. Pat. No. 5,457,520 relates to a bearing for supporting a moving member on a support structure. The bearing includes a substantially U-shaped member having an internal periphery and an external periphery. The bearing also includes a first securer, associated with the internal periphery of the U-shaped member, for securing the moving member to the U-shaped member and a second securer, associated with the external periphery of the U-shaped member, for securing the U-shaped member to the support structure. U.S. Pat. No. 4,804,277 relates to a bearing mounting system for mounting and retaining a rotatable shaft between first and second bearings mounted to first and second spaced frame members of a machine frame, utilizing commercially available bearings, with respective inner and outer races. Both bearings inner races are press fitted onto the shaft. U.S. Pat. No. 4,134,175 relates to a non-rotating sleeve type bushing in which an eccentric flange integral with the bushing and projecting radially outwardly therefrom is so formed as to be received in a complementarily contoured flange recess in a bearing housing whereby rotation of the bushing with respect to the bearing housing is precluded by a positive mechanical locking action provided by the shear resistance of the flange member. All documents cited herein, including the foregoing, are incorporated herein by reference in their entireties. SUMMARY OF THE INVENTION The present invention relates to embodiments of a bearing with snap-fit features for use in walls of reproduction machines. In accordance with one aspect of the present invention, there is provided, a bearing having an elongated body and including a first portion and a second portion. The first portion has a first length, a first outer periphery, a first surface, and at least one notch. The second portion has a second length, an opening, and a lumen for receiving and supporting a shaft, a second outer periphery, and at least one resilient member originating from the second outer periphery of the second portion. The at least one resilient member extends radially outward toward the first portion and is spaced from the second outer periphery of the second portion over a portion of the elongated body. The first surface of the first portion extends radially inward from the first outer periphery to the second outer periphery on the second portion. The at least one resilient member is movable between a first position and a second position for removable securement to a wall. In accordance with another aspect of the present invention, there is provided, a bearing and shaft assembly in an electrostatographic machine including a development station, a bearing, wall, and a shaft. The bearing includes: (a) a first portion having a first length, a first outer periphery, a first surface, and at least one notch; (b) a second end portion having a second length, an opening, and a lumen for receiving and supporting a shaft; and (c) at least one resilient member originating from the outer periphery of the second portion. The resilient member extends radially outward toward the first portion and is spaced from the outer periphery of the second portion over a portion of the second portion. The resilient member has an end movable between a first position and a second position to cooperate with the wall of a housing of the electrostatographic machine. The bearing is adapted for removable securement to the wall. The shaft is rotatably disposed in the lumen of the bearing. In accordance with another aspect of the present invention, there is provided, a bearing including an elongated body. The elongated body includes a first portion and a second portion. The first portion has a length, perimeter, and at least one notch. The second portion has a length and forms an aperture to support a second member being rotatably fittable therein. At least one resilient member is formed integral with the body. The body and the resilient member cooperate to secure a wall therebetween. The first portion includes a flange extending outwardly from the second portion. The flange and the at least one resilient member cooperate with the wall to limit displacement of the body with respect to the wall in a direction of an axis of the second member. Still other features, aspects and advantages of the present invention and methods of construction of the same will become readily apparent to those skilled in the art from the following detailed description. As will be realized, the invention is capable of other and different embodiments and methods of construction, and its several details are capable of modification in various obvious respects, all without departing from the invention. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a perspective view of a mounting system for an embodiment of the present invention; FIG. 2 illustrates a front elevational view of the bearing of FIG. 1; FIG. 3 illustrates a side elevational view of the bearing of FIG. 1; FIG. 4 illustrates a cross-sectional view of the bearing of FIG. 1 disposed in a wall along with a shaft disposed in the bearing; FIG. 5 illustrates a front elevational view of another embodiment of the bearing; FIG. 6 illustrates a perspective view of a mounting system for another embodiment of the present invention of FIG. 5; FIG. 7 illustrates a cross-sectional view of the bearing of FIGS. 5-6 along with a gear disposed thereon; and FIG. 8 is a schematic elevational view of an electrophotographic printing machine utilizing the present invention. DETAILED DESCRIPTION OF THE INVENTION While the principles of the present invention will be described in connection with an electrostatographic reproduction machine, it should be understood that the present invention is not limited to that embodiment or to that application. Therefore, it is should be understood that the principles of the present invention extend to all alternatives, modifications and equivalents as may be included within the spirit and scope of the appended claims. The present invention relates to embodiments of a bearing for use in walls of reproduction machines. Although the bearing of the present invention is particularly well adapted for use in the illustrative printing machine, it will become evident that the bearing is equally well suited for use in a wide variety of machines and are not necessarily limited in its application to the particular embodiment shown herein. Referring to FIG. 8 of the drawings, an illustrative reproduction machine incorporating the bearing of the present invention is shown. The reproduction machine employs a photoconductive belt 11 . Belt 11 moves in the direction of arrow 13 to advance successive portions sequentially through the various processing stations disposed about the path of movement thereof. Belt 11 is entrained about stripping roller 15 , tensioning roller 17 , idler roll 19 and drive roller 21 . As roller 21 rotates, it advances belt 11 in the direction of arrow 13 . Initially, a portion of the photoconductive surface passes through charging station M. At charging station M, two corona generating devices indicated generally by the reference numerals 23 and 25 charge the photoconductive belt 11 to a relatively high, substantially uniform potential. Next, the charged portion of the photoconductive surface is advanced through imaging station N. At the imaging station, an imaging module indicated generally by the reference numeral 27 , records an electrostatic latent image on the photoconductive surface of the belt 11 . Imaging module 27 includes a raster output scanner (ROS). The ROS lays out the electrostatic latent image in a series of horizontal scan lines with each line having a specified number of pixels per inch. Other types of imaging systems may also be used employing, for example, a pivoting or shiftable LED write bar or projection LCD (liquid crystal display) or other electro-optic display as the “write” source. The imaging module 27 (ROS) includes a laser 110 for generating a collimated beam of monochromatic radiation 122 , an electronic subsystem (ESS) associated with the machine electronic printing controller 76 transmits a set of signals via 114 corresponding to a series of pixels to the laser 110 and/or modulator 112 , a modulator and beam shaping optics unit 112 , which modulates the beam 122 in accordance with the image information received from the ESS, and a rotatable polygon 118 having mirror facets for sweep deflecting the beam 122 into raster scan lines which sequentially expose the surface of the belt 11 at imaging station N. A user interface (UI) 150 is associated with the controller 76 . Thereafter, belt 11 advances the electrostatic latent image recorded thereon to development station O. Development station O has three magnetic brush developer rolls indicated generally by the reference numerals 35 , 36 and 38 . A paddle wheel picks up developer material and delivers it to the developer rolls. When the developer material reaches rolls 35 and 36 , it is magnetically split between the rolls with half of the developer material being delivered to each roll. Photoconductive belt 11 is partially wrapped about rolls 35 and 36 to form extended development zones. Developer roll 38 is a clean-up roll. The latent image attracts toner particles from the carrier granules of the developer material to form a toner powder image on the photoconductive surface of belt 11 . Belt 11 then advances the toner powder image to transfer station P. At transfer station P, a copy sheet is moved into contact with the toner powder image. First, photoconductive belt 11 is exposed to a pretransfer light from a lamp (not shown) to reduce the attraction between photoconductive belt 11 and the toner powder image. Next, a corona, generating device 41 charges the copy sheet to the proper magnitude and polarity so that the copy sheet is tacked to photoconductive belt 11 and the toner powder image is attracted from the photoconductive belt to the copy sheet. After transfer, corona generator 42 charges the copy sheet to the opposite polarity to detack the copy sheet from belt 11 . Conveyor 44 then advances the copy sheet to fusing station Q. Fusing station Q includes a fuser assembly 46 which permanently affixes the transferred toner powder image to the copy sheet. Preferably, fuser assembly 46 includes a heated fuser roller 48 and a pressure roller 51 with the powder image on the copy sheet contacting fuser roller 48 . The pressure roller is cammed against the fuser roller to provide the necessary pressure to fix the toner powder image to the copy sheet. The fuser roll 48 is internally heated by a quartz lamp. Release agent, stored in a reservoir, is pumped to a metering roll. A trim blade trims off the excess release agent. The release agent transfers to a donor roll and then to the fuser roll. After fusing, the copy sheets are fed through a decurler 52 . Decurler 52 bends the copy sheet in one direction to put a known curl in the copy sheet and then bends it in the opposite direction to remove that curl. Forwarding rollers 54 then advance the sheet to duplex turn roll 56 . Duplex solenoid gate 58 guides the sheet to the finishing station R, or to duplex tray 61 . At finishing station R, copy sheets are stacked in a compiler tray and attached to one another to form sets. When duplex solenoid gate 58 diverts the sheet into duplex tray 61 . Duplex tray 61 provides an intermediate or buffer storage for those sheets that have been printed on one side and on which an image will be subsequently printed on the second, opposite side thereof, i.e., the sheets being duplexed. The sheets are stacked in duplex tray 61 facedown on top of one another in the order in which they are copied. To complete duplex copying, the simplex sheets in tray 61 are fed, in seriatim, by bottom feeder 62 from tray 61 back to transfer station P via conveyor 64 and rollers 66 for transfer of the toner powder image to the opposed sides of the copy sheets. Inasmuch as successive bottom sheets are fed from duplex tray 61 , the proper or clean side of the copy sheet is positioned in contact with belt 11 at transfer station P so that the toner powder image is transferred thereto. The duplex sheet is then fed through the same path as the simplex sheet to be advanced to finishing station R. The high capacity variable sheet size sheet feeder 100 is the primary source of copy sheets. Feed belt 81 feeds successive uppermost sheets from the stack to a take-away drive roll 82 and idler rolls 84 . The drive roll and idler rolls guide the sheet onto transport 86 . Transport 86 advances the sheet to rolls 66 which, in turn, move the sheet to transfer station P. Secondary tray 68 and auxiliary tray 72 are secondary sources of copy sheets. Copy sheets are fed to transfer station P from the secondary tray 68 or auxiliary tray 72 . Sheet feeders 70 , 74 are friction retard feeders utilizing feed belts and take-away rolls to advance successive copy sheets to transport 64 which advances the sheets to rolls 66 and then to transfer station P. The copy sheet is registered just prior to entering transfer station P so that the sheet is aligned to receive the developed image thereon. Invariably, after the copy sheet is separated from the photoconductive belt 11 , some residual particles remain adhering thereto. After transfer, photoconductive belt 11 passes beneath corona generating device 94 which charges the residual toner particles to the proper polarity. Thereafter, the pre-charge erase lamp (not shown), located inside photoconductive belt 11 , discharges the photoconductive belt in preparation for the next charging cycle. Residual particles are removed from the photoconductive surface at cleaning station S. Cleaning station S includes an electrically biased cleaner brush 88 and two de-toning rolls 90 . The various machine functions are regulated by a controller 76 . The controller 76 is preferably a programmable microprocessor which controls all of the machine functions hereinbefore described. The controller provides a comparison count of the copy sheets, the number of documents being recirculated, the number of copy sheets selected by the operator, time delays, jam corrections, etc. The control of all of the exemplary systems heretofore described may be accomplished by conventional control switch inputs from the printing machine consoles selected by the operator. Conventional sheet path sensors or switches may be utilized to keep track of the position of the document and the copy sheets. Turning now to FIG. 1, illustrated is a partial cut-away view from the FIG. 8 reproduction machine illustrating one of the bearings 10 of the present invention as it is about to be installed in a wall 50 . Also shown is a shaft 40 as it is about to be installed into a shaft support portion 12 of the bearing 10 . The shaft support portion 12 has a bore 14 (not shown) that is formed in a generally cylindrical shape to allow rotation of the shaft 40 therein. A flange 16 extends radially from the shaft support portion 12 . In operation, the bearing 10 is inserted into the wall 50 until a surface 18 (not shown) of the flange 16 contacts a surface 20 of the wall 50 . A plurality of flexible members 22 are used to hold the bearing 10 substantially secure to the wall 50 . The flexible members 22 originate from an outside surface 24 on the shaft support portion 12 and then extend toward the flange 16 . After the surface 18 of the flange 16 is positioned against the wall 50 , radial pressure to the flexible members 22 is released and the ends 26 of the flexible members 22 adjust to their free state to a position which is wider than an opening 28 in the wall 50 . The ends 26 of the flexible members 22 apply force against the surface 30 of the wall 50 and physically impede the bearing 10 from rotating about its axis and from becoming unsecured from the wall 50 . The ends 26 of the flexible members 22 have sufficient surface area for contact with the wall 50 to limit rotation of the bearing 10 . FIGS. 2 and 3 illustrate front and side elevational views of the bearing 10 . The flexible members 22 are flexible and are moveable from an expanded free state to a lower profile state, less than the expanded free state, sufficient to allow passage of the members 22 through the opening 28 in the wall 50 . The bearing 10 may be molded of plastic, in one piece. The flange 16 has notches to enable manufacture of the members 22 in a two-part mold using an injection molding process. The notches may also aid in gripping the bearing 10 during insertion. The opening 28 in the wall 50 may also have notches to aid in insertion of the bearing 10 and to allow the members 22 to clear the wall 50 . The bearing 10 then may be rotated such that the flexible members 22 are situated away from the notches in the opening 28 . Alternatively, the ends 26 of the flexible members 22 may be formed into a offset shape and extend sufficiently over an edge of the wall 50 into the notch area of the wall opening 28 to prevent rotation of the bearing 10 . In addition, the ends 26 of the flexible members 22 may also have a chamfer or angular portions for aiding positioning of the ends 26 into the notch of the opening 28 . The flange 16 includes an end cap to restrain the end of the shaft 40 thus making the use of clips such as ‘e’ clips unnecessary. The flange 16 may be circular, square, rectangular, or irregular, provided it is of sufficient size, for example, a sufficient diameter to provide stability against the surface 20 of the wall 50 and to cover the opening 28 in the wall 50 . The dimensions of the bearing 10 are intended to be suited for applications inside a reproduction machine although additional sizes and uses are envisioned. The shaft support portion 12 may have a wall thickness “A” ranging from about 0.0625 inches to about 0.1875 inches. The shaft 40 has a diameter of ranging from about 6-10 mm (0.2362 inches-0.3938 inches) and the wall 50 has a thickness of approximately 1-2 mm (0.0394 inches-0.0788 inches). The bearing 10 may have a space WT between surface 18 of the flange 16 and the end 26 of the flexible members 16 in order to allow the wall 50 to fit therein. The flange 16 may have a diameter “B” ranging from about 0.5 inches to about 1.0 inches and a length “J” ranging from about 0.25 inches to about 0.5 inches. The shaft support portion 12 may have an outside diameter “C” ranging from about 0.3125 inches to about 0.625 inches and a length “D” ranging from about 0.3125 inches to about 0.625 inches. The shaft support portion 12 may have a bore 14 with an inside diameter “E” ranging from about 0.25 inches to about 0.5 inches. The flexible members 22 have a length “F” ranging from about 0.3 inches to about 0.6 inches and they extend radially outward from the outside surface 24 of the shaft support portion 12 for a distance “G” ranging from about 0.1 inches to about 0.2 inches. In use, an end 26 of the flexible member 22 may move radially a distance ranging from about 0.05 inches to about 0.1 inches. The distance H measured between the outer most surfaces of the flexible member 22 ranges from about 0.5125 inches to about 1.025 inches. FIG. 4 illustrates a cross-sectional view of the bearing 10 disposed in a wall 50 . The shaft 40 is disposed in the shaft support portion 12 of the bearing 10 . The bearing 10 is intended to support a rotatable shaft 40 which may be used for idler rollers, drive rollers, belt rollers or any other shaft use within a reproduction machine. An alternative embodiment of the bearing 10 is illustrated in FIGS. 5-7 in which the flange portion 16 includes an opening 32 to allow a portion of the shaft 40 to pass through. FIG. 5 illustrates an end view of the bearing 10 with the opening 32 for the shaft 40 to partially extend therethrough. Turning now to FIG. 6, illustrated is a partial cut-away view of the bearing 10 of FIG. 5 as it is about to be installed in a wall 50 . Also shown is a shaft 40 as it is about to be installed into an end 34 of the bearing 10 for rotation in a shaft support portion 12 . In FIG. 7, illustrated is a cross-sectional view of the bearing 10 of FIGS. 5-6 disposed in a wall 50 . The bearing 10 is removeably securable to the wall 50 . The shaft 40 is installed into an end of the bearing 10 and extends partially out the other end through the flange 16 . The shaft 40 is shown stepped to a smaller diameter prior to passing through the flange 16 . A gear 60 is disposed on the end of the shaft 40 . As the gear 60 rotates, the shaft 40 rotates in the shaft support portion 12 . Other embodiments and features of the beraring 10 are also envisioned. A resilient member may be spaced apart from another resilient member an angular distance θ ranging from about 60 degrees to about 180 degrees. The bearing 10 may be constructed of plastic including Delrin® 500CL which is commercially available from Dupont®. The bearing may include a plastic resin such as an Acetal resin. Other materials such as nylon may also be used so as to provide a generally low friction bearing surface for the rotation shaft 40 . The inside surface of the bearing 10 may have a coefficient of friction ranging from about 0.2 to about 0.3. The plastic may have hardness of about 1.3 ft-lb/in. The bearing 10 is advantageously made of one material using a generally simple molding process. In an alternative embodiment, the bearing 10 may include a metal insert bearing (phosphor bronze) or ball race in the bore 14 . In summary, a bearing 10 is provided for supporting a rotatable shaft 40 in a wall 50 of a reproduction machine. The bearing 10 described herein can generally be easily mounted in a reproduction machine, can generally allow easier assembly, and can generally be replaced without the necessity of complex disassembly of many components. While this invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

A bearing for use in a reproduction machine includes an elongated body having an elongated first portion and an elongated second portion. The first portion extends radially outward from the second portion. The second portion includes a lumen for receiving and supporting a shaft. Resilient elongated members originate from the second portion and extend radially outward toward the first portion and are spaced from the second portion over a portion thereof. The resilient members are movable between a first position and a second position for removable securement to a wall in a reproduction machine.

BACKGROUND The present invention relates to a device or an apparatus, as well as a method for stranding long winding materials, in particular metal winding materials, such as wires, lacings, cables as well as insulated conductors, such as small wires or the like. A complete assembly for stranding long winding materials, which includes an apparatus for stranding long winding materials as well as a method for stranding long winding materials making use of the apparatus, is disclosed in U.S. Pat. No. 6,427,432 B1. The total assembly of US '432 is a so-called “lyre-type horizontal pairing machine”, abbreviated “PHL”, and comprises a horizontally arranged rotary flyer-type payout system with a rotary flyer. A payout system is arranged within the body supporting the rotary flyer and is decoupled from the rotation of the flyer and serves for tangential payout of a first strand. A second strand is supplied by a second payout system, which is arranged in drawing direction before the rotary flyer payout system and is guided over the rotary flyer of the flyer-type payout system. At the end of the flyer-type payout system, a device is arranged for stranding the first and second strands. It is a stranding drum, which is a functionally important element for the assembly of the two individual strands. This stranding drum, a cylindrical rotary body, comprises a first passage for guiding the first wire or strand through the stranding drum and a second passage for guiding the second wire or strand through the stranding drum. The first passage interconnects a first central inlet on the inlet end side of the stranding drum with a first eccentric or offset outlet of the outlet end side of the stranding drum. The second passage interconnects a second offset inlet on the inlet end side of the stranding drum with a second, also offset outlet on the outlet end side of the stranding drum. After passing through the stranding drum, the first and second wires are stranded together at a stranding point. A drawback of the “PHL” system appears to be that both of the individual wires or strands must pass the entire length of the stranding drum, due to the constructive configuration of the “PHL”. This requires that the stranding drum on the whole can only be arranged in drawing direction following the rotary flyer-type payout system. This would oppose a general need for a compact form of the entire stranding assembly. A further drawback of the “PHL” system, as described in the embodiment, in particular for the configuration of the stranding drum, can only operate as an assembly for stranding two wires. An operation of the rotary flyer payout system as a back twisting device for individual wires appears only possible for “PHL” with correspondingly complicated re-fitting of the “PHL”. The “PHL” of US '432 therefore appears to be less flexible. The object of the present invention is therefore to provide an apparatus as well as a method for stranding long winding materials, which allows a more compact construction of the entire stranding assembly as well as allowing a stranding assembly which is more flexible in use. SUMMARY The apparatus for stranding of long winding materials according to the present invention comprises a substantially cylindrical rotary body with at least one first passage for guiding a first winding material through the cylindrical rotary body and with at least one second passage for guiding a second winding material through the cylindrical rotary body. The first passage interconnects a first offset or peripheral inlet on a first end side of the rotary body with a first offset outlet on a second end side of the rotary body, opposite the first end side. The second passage connects a second inlet, arranged on a surface of the rotary body extending between the two end sides, with a second offset outlet on the second or first end side of the rotary body. According to the method of stranding long winding material, a first winding material is guided through a first passage of a substantially cylindrical rotary body and a second winding material is guided through a second passage of the substantially cylindrical rotary body. The first and second winding materials, after passage through the substantially cylindrical rotary body, are stranded at a stranding point. The first passage connects a first offset inlet on a first end side of the rotary body with a second offset outlet on a second end side of the rotary body, opposite the first end side. The second passage connects a second inlet, arranged on a surface of the rotary body (cylindrical surface) extending between the two end sides, with a second offset outlet on the second end side of the rotary body. The terms “inlet” and “outlet” used here in conjunction with the passage of the winding material through the rotary body should not be understood as limited to a passage of the winding material in this inlet-outlet direction, i.e. in the direction from the inlet to the direction of the outlet. A passage of the winding material in the opposite direction, i.e. from the outlet in the direction of the inlet is also possible. Furthermore, the terms “offset” or “peripheral” or an “offset or peripheral inlet/outlet” are understood in that a radial displacement or radial distance (of the inlet/outlet) is present with respect to the rotational axis or center axis of the substantially cylindrical rotary body. The other terms used here “centrally” or “central” correspondingly mean that no radial displacement or no radial distance (of an inlet/outlet) is present to the rotational axis or center axis of the substantially cylindrical rotary body and that such a central inlet or outlet lies on the rotational axis or center axis of the substantially cylindrical rotary body. Further preferred configurations and embodiments of the invention result from the dependent claims. The described embodiments and/or configurations discussed below refer both to the method and also the apparatus. The stranding of several wires or strands is a further embodiment, by which one, two or even more first passages and/or one, two or even more second passages are provided respectively for guiding further winding materials through the cylindrical rotary body. With at least one further first passage and one further second passage, the second offset outlet of the second passage can be arranged opposite the second offset outlet of the at least one second passage. In a further preferred embodiment, the second offset outlet of the second passage and the first offset outlet of the first passage can be arranged on the same end side of the cylindrical rotary body. In a further preferred embodiment, the two offset outlets are arranged such that they have the same radial distance from a rotational axis of the cylindrical rotary body and are arranged oppositely at 180°. In a further preferred embodiment, the first and/or second passages are substantially parallel, in particular at the same radial distance to the rotational axis of the substantially cylindrical rotary body. Particularly advantageous, especially for a compact construction of the stranding assembly is when the cylindrical rotary body is part of a rotary shaft of a rotary flyer, in particular of a rotary flyer payout system, and/or rotates with a rotary flyer, in particular a rotary flyer payout system or is connected thereto for rotation. In these cases, the stranding device or the rotary body is integrated into the rotary flyer payout system and/or is an integral element of a rotary flyer payout system. A strand guidance can be improved and frictional losses avoided if a guiding device is provided to input the second winding material at the second inlet, in particular a deflection roller. In a further preferred embodiment, a third passage is provided for guiding a third winding material through the cylindrical rotary body. This third passage can be configured such that it connects a third central inlet at the first or second end side of the rotary body with a third outlet, arranged on the surface of the rotary body (cylindrical surface) between the two end sides. It is noted that the third winding material can also simultaneously be guided with the first and/or second winding material through the rotary body. However, it is preferred when the third winding material instead of the first and the second winding materials is guided in an alternative operation through the rotary body. For example, in normal operation the first and second winding materials are passed through the rotary body and a stranding of the first and second winding materials takes place. However in the alternative operation, the third winding material instead of the first and second winding materials passes through the rotary body and a back twisting of the third winding material takes place. A guiding device at the outlet of the third winding material can also be provided, in particular a deflection roller. Furthermore, the first and the third and/or the second and the third and/or the first, the second and the third passage can run substantially parallel to one another and/or to a rotational axis of the substantially cylindrical rotary body. The substantially cylindrical rotary body can be provided of a metallic material, such as steel or aluminum and/or the passage through the rotary body can be a (longitudinal) bore or a (longitudinal) groove or the like. The special flexibility allows applications in the scope of stranding or pre-stranding at least two winding materials and also in the scope of back twisting of one of the individual winding materials. The first winding material is guided through the first passage for the purpose of stranding, in particular pre-stranding, of a first winding material, in particular a first strand, and the second winding material, in particular a second strand, especially for metallic first and second winding materials, such as wires, lacings, cables and the like. The second winding material is guided through the second passage. After passing through the cylindrical rotary body, the first and second winding materials are stranded at a stranding point. When stranding or in particular when pre-stranding of the first and second winding materials, it can be provided that the second winding material be guided prior to the second passage in drawing direction over a rotary flyer of a rotary flyer payout system and/or that the first winding material prior to being passed through the first passage be drawn off from a payout system of the rotary flyer payout system as a tangential payout. Furthermore, when stranding, in particular when pre-stranding, of the first and the second winding material, it can be provided that the second winding material before being guided over the rotary flyer of the rotary flyer payout system in drawing direction is drawn off from a further rotary flyer payout system as a further tangential payout system. The rotary flyer payout system or systems can be arranged horizontally or vertically. The third winding material is guided through the third passage when used for back twisting of the third winding material, in particular a third strand. After passing through the cylindrical rotary body, the third winding material is guided over a rotary flyer of a rotary flyer payout system, upon which the third winding material receives a back twisting. The rotary flyer payout system in this case can also be arranged horizontally or vertically. When back twisting the third winding material, it can be provided that the third winding material before passing through the cylindrical rotary body in drawing direction is drawn off of a drawing device of the rotary flyer payout system. Preferably, the apparatus, the method or its embodiments can be combined with or supplemented with detection means and/or regulation means for the winding material tension and/or drawing force of the winding material. A first force measuring device, in particular a load cell force sensor can be provided for measuring a tensile force and/or tension in a winding material. The first winding material can be guided over the sensor before passing through the first passage of the substantially cylindrical rotary body. In addition, a third force measuring device can be provided, in particular a third load cell or force sensor, also for measuring a tensile force and/or tension in a winding material. In addition, a stranded product out of the first and second winding material can be guided over the sensor after passing through the substantially cylindrical rotary body. In a further embodiment, a second force measuring device, in particular a second load cell or force sensor, can be provided for measuring the tensile force and/or tension in a winding material through which the second winding material is guided before passing through the second passage of the substantially cylindrical rotary body. When detecting and/or regulating a winding material tension and/or drawing force, in particular for detecting a desired drawing force of the second winding material and/or regulating a second drawing force of the second winding material, a first drawing force of the first winding material can be measured with a first force measuring device and/or with the second force measuring device a second drawing force of the second winding material. The tensile force in the stranded product can be measured with the third force measuring device. The desired or set drawing force of the second or first winding material can be determined and/or the second or first drawing force of the second winding material can be regulated by using the first drawing force of the first winding material or the second drawing force of the second winding material and the tensile force in the stranded product. BRIEF DESCRIPTION OF THE DRAWINGS Further advantages, features and applications of the present invention can be taken from the following description of embodiments in conjunction with the attached drawings and the list of reference numerals. The drawings show components and elements of stranding assemblies in generally used, common illustrations understandable for the skilled person. Shown in schematic presentation: FIG. 1 is a cross sectional drawing of a lower rotary shaft of a vertical rotary flyer payout system with integrated stranding element according to a first and/or second embodiment. FIG. 2 is an illustration of a lower portion of a vertical rotary flyer payout system with a lower rotary shaft with integrated stranding element as well as deflection rollers for strand guidance, which illustrates the path of a strand when stranding according to a first and/or second embodiment. FIGS. 3 a and 3 b are illustrations of a lower portion of a vertical rotary flyer payout system with lower rotary shaft (in side view (a) as well as section illustration (b)) with integrated stranding element as well as deflection rollers for strand guidance according to a first and/or second embodiment. FIG. 4 shows a perspective illustration of a vertical rotary flyer payout system with a stranding element integrated in a lower rotary shaft of the rotary flyer payout system of a first and/or second embodiment. FIG. 5 is an overview of a first portion of a stranding assembly with two vertical rotary flyer payout systems used for (pre) stranding of two strands as well as for back twisting one strand according to a first and/or second embodiment. FIG. 6 is an illustration of a lower portion of a vertical rotary flyer payout system with lower rotary shaft with integrated stranding element according to a first and/or second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following embodiments comprise in particular a stranding element 100 or 100 ′ (see FIG. 1 ) for combining two individual strands 102 and 103 in this case (see FIG. 2 ), which is formed as an integral part of a lower rotary shaft 600 or 600 ′ of a vertically arranged rotary flyer payout system, in the present embodiments a first 650 and a second 660 rotary flyer payout system. It is remarked that the stranding element 100 or 100 ′ as described here for this embodiment in a vertical rotary flyer payout system can be used correspondingly in a horizontal rotary flyer payout system. The stranding element 100 or 100 ′, as to be discussed below for the embodiments, is employed for pre-stranding (a three-fold total stranding) of the first 102 and the second 103 strands (embodiment 1), employed for a back twisting of a first 102 ′ or a second 103 ′ strand (embodiment 2) as well as employed for a stranding in combination with a strand tension/drawing force regulation of the third strand 103 (embodiment 3). Embodiment/Applications In Review FIG. 5 shows an overview of a portion 670 of a combined total stranding assembly, which can be used for the pre-stranding of the first 102 and the second 103 strand (embodiment 1), also for back twisting of the first 102 ′ or the second 103 ′ strand (embodiment 2) as well as also for the pre-stranding in combination with strand tension regulation and drawing force regulation for the second strand 103 (embodiment 3). The described strand tension regulation in the embodiment 3 can however also be the protected subject matter alone, without the constructive details of the stranding assembly according to embodiment 1 or the back twisting device of embodiment 2. Initially, the essential elements of the portion 670 shown in FIG. 5 of the entire stranding assembly are described, which are also illustrated and where reference is also made to the further FIGS. 1 to 4 and 6 . FIG. 5 shows a first 650 as well as a second 660 vertically arranged rotary flyer payout system, configured as a single flyer system with a rotatable flyer 300 or 300 ′, for example a sleeve winder. Guide rollers 301 , 301 ′ for strand guidance are arranged on the rotary flyers 300 , 300 ′. The rotary flyers 300 , 300 ′ are rotatably mounted through a lower 600 , 600 ′ and an upper 610 , 610 ′ rotary shaft and are driven by a drive unit 520 , 520 ′. The stranding element 100 , 100 ′ is integrated into the lower rotary shaft 600 , 600 ′ or the lower rotary shaft 600 , 600 ′ is configured such that it simultaneously acts as the stranding element 100 , 100 ′. The two rotary flyer payout systems 650 , 660 are arranged parallel to one another and can be operated and driven in synchronized manner, as in the stranding operation in embodiment 2. Within the rotary body, spanned by the rotary flyers 300 , 300 ′, and on their rotational axes 310 , 310 ′ is a dancer-regulated payout system 500 , 500 ′, which comprises a payout spool 400 , 400 ′ (payout/pick-up spool) mounted in a spool frame 401 , 401 ′. The rotary flyer 300 , 300 ′ and the payout system 500 , 500 ′ can be decoupled from one another by decoupling a rotary flyer drive, as in embodiment 1 in back twisting operation. In stranding operation (see embodiment 1), the first strand 102 is paid out from the payout spool 400 and in the back twisting operation (embodiment 2), the first strand 102 ′ is paid out under dancer regulation and with nearly constant tensile force (see embodiment 3). In stranding operation (embodiment 1) the second strand 103 is paid out from the payout spool 400 ′ and in the back twisting operation (embodiment 2) the second strand 103 ′ is paid out in dancer regulation and with nearly constant tensile force (embodiment 3). Corresponding means are provided for paying out the respective strands on the corresponding payout systems 500 , 500 ′ or the respective payout spools 400 , 400 ′, such as a guiding nipple 410 , deflection rollers and guide rollers 421 , 431 as well as associated fastening devices 410 , 422 , 440 . In the system 670 shown in FIG. 5 , as well as in the FIG. 1 to 4 and FIG. 6 , various strand guiding elements are illustrated such as the guiding nipple 501 , deflection rollers and pulleys 510 and guiding rollers 301 for guiding the strands 102 , 102 ′ or 103 , 103 ′. The deflection rollers and pulleys 510 in the embodiments preferably have a diameter of at least 120 mm. To minimize the total strand drawing forces in the assembly or system 670 , a single disc drawing device with a pressing belt and dancer regulation 530 is installed for the drawing action. Furthermore, the two dancer regulated payout systems 500 , 500 ′ of the system 670 each comprise a device for tensile force or strand tension measurement, here a first and a second force sensor 700 , 701 , which are arranged in drawing direction directly following the payout position of the respective strands 102 , 102 ′ or 103 , 103 ′ in the corresponding rotary flyer payout system 650 , 660 . The first 102 or the second 103 strand is passed over these first or second force sensors 700 , 701 and their tensile force or their strand tension is measured. In addition, a further, in this case a third, force sensor 710 is provided, which is arranged in drawing direction following the stranding element 100 . The stranded product out of the first 102 and the second strand 103 (embodiment 1) is passed over this sensor and its tensile force or strand tension is measured. Stranding element 100 or 100 ′ (see in particular FIG. 1 or FIGS. 2 to 6 ). The stranding element 100 , 100 ′, as part of the lower rotary shaft 600 , 600 ′, as shown in FIG. 1 to 6 , comprises a longitudinally extended substantially cylindrical component rotationally mounted about a rotational axis 101 , which is connected by means of a fastening element 302 with the rotary flyer 300 , 300 ′ rotating about the rotational axis 101 for common rotation. Mounting elements 150 , 160 with ball bearings 151 to 154 are provided for mounting the lower rotary shaft 600 , 600 ′ or the stranding elements 100 , 100 ′. In addition, toothed belt rings 170 , 171 are provided on the lower end 144 and the upper end 140 of the lower rotary shaft 600 , 600 ′ or the stranding element 100 , 100 ′. The stranding element 100 , 100 ′ comprises three passages or bores 110 , 120 and 130 for guiding the first 102 and the second 103 strand or the first and second strand 102 ′, 103 ′ in stranding operation as well as in back twisting operation. The first passage 110 , which serves for passing the first strand 102 in stranding operation, connects an offset or peripheral inlet 111 at the upper end side or inlet end side 140 of the stranding element 100 , 100 ′ in a path parallel to the rotational axis with a radial outlet 112 at the lower end side or outlet end side 141 of the stranding element 100 , 100 ′. The second passage 120 , which serves for passage of the second strand 103 , connects an inlet 121 of the stranding element 100 , 100 ′ arranged approximately centrally on the surface 143 of the stranding element 100 , 100 ′ in the longitudinal direction of the stranding element 100 , 100 ′ in an approximately parallel path to the rotational axis 101 with a radial outlet 122 on the outlet end side 141 of the stranding element 100 , 100 ′. A deflection roller 123 for guiding the second strand 103 is arranged at the inlet 121 . The third passage 130 , which serves passage of the first or second strand 102 ′, 103 ′ in back twisting operation, connects a central inlet 131 on the inlet end side 140 in an approximate parallel path to the rotational axis 101 with an outlet 132 arranged on the forward one-third of the surface 143 of the stranding element 100 , 100 ′ seen in the longitudinal direction of the stranding element 100 , 100 ′. A deflection roller 133 for guiding the strand 102 ′, 103 ′ is arranged at the outlet 132 . The path of the strands 102 , 103 or 102 ′, 103 ′ through the stranding element 100 , 100 ′ in stranding operation as well as in back twisting operation are designated in FIG. 1 with the reference numerals 105 , 106 and 107 . A double dot-dashed line 105 illustrates the path of the first strand 102 through the stranding element 100 in the case of stranding. The triple dot-dashed line 106 illustrates the path of the second strand 103 through the stranding element 100 , 100 ′ also in the case of stranding. The quadruple dot-dashed line 107 illustrates the path of the strand 102 ′ or 103 ′ through the stranding element 100 , 100 ′ in the case of back twisting. Embodiment 1:Dancer-Regulated Payout System when Used as Pre-Stranding Assembly or as Stranding Element 100 with Pre-Stranding In the following, the above system 670 when used as a pre-stranding assembly is described (for a three-fold total stranding). In this case, the second rotary flyer payout system 660 of the flyer driver is decoupled and the payout system 500 ′ is used for “normal” tangential payout. From here, the second strand 103 is drawn off under dancer regulation with nearly constant tensile force and is guided over the stationary rotary flyer 300 ′ of the second rotary flyer payout system 660 . The first rotary flyer payout system 650 is also used only for tangential payout, from whose payout system 500 the first strand 102 is also drawn off in dancer-regulated manner. The second strand 103 is then passed further over the rotary flyer 300 of the first rotary flyer payoff system 650 . The two strands 102 , 103 , as described above or in the following in more detail, are then guided and rotated through the stranding element 100 , which is part of the lower rotary shaft 600 with the rotary flyer 300 and in this manner guided to the first stranding point 220 . Through the rotation of the rotary flyer 300 of the first rotary flyer payout system 650 , the strands 102 , 103 are stranded, i.e. form a pair. The pair 220 , stranded in this manner, is then passed through a further second stranding point—not illustrated—and receives a second stranding operation. In addition, the product is passed through a pair stranding assembly, where it receives the third stranding operation when exiting from the rotary flyer of this pair stranding assembly. In this manner, the individual strands receive a back twisting, normally 33%, depending on the stranding velocity in the first stranding operation. FIG. 1 shows the stranding element 100 , 100 ′ as it is employed in the pre-stranding of the first 102 and the second 103 strands. A double dot-dashed line 105 illustrates the path of the first strand 102 through the stranding element 100 in the case of pre-stranding. The triple dot-dashed line 106 illustrates the path of the second strand 103 in this case. In the case of pre-stranding, as shown by the path 105 , the first strand 102 is passed at the inlet end side 140 through the radial inlet 111 into the stranding element 100 or the lower rotary shaft 600 . The further guidance or passage 110 of the first strand 102 runs parallel to the rotational axis 101 of the stranding element 100 , until the strand 102 leaves the stranding element 100 via the outlet 112 at the outlet end side 141 . The second strand 103 , whose path through the stranding element 100 is designated with the reference numeral 106 , is passed through the second passage 120 of the stranding element 100 . It enters into the stranding element 100 , 100 ′ through the inlet 121 arranged approximately centrally on the surface 143 of the stranding element 100 , 100 ′ seen in longitudinal direction of the stranding element 100 , 100 ′. The strand 103 passes in an approximately parallel path to the rotational axis 101 and exits at a radial outlet 122 on the outlet end side 141 of the stranding element 100 . A deflection roller 123 for guiding the second strand 103 is arranged at the inlet 121 , by which the second strand 103 is guided into the stranding element 100 . Embodiment 2:Dancer-Regulated Payout System in Use as Back Twisting Payout or Stranding Element 100 , 100 ′ Under Back Twisting In the following, the above system 670 is described in a further application in back twisting operation. In this case, the two vertical and parallel rotary flyer payout systems 650 and 660 are operated for flyer payout, where the two flyer payout systems are operated simultaneously and in synchronization. The two payout spools 400 , 400 ′ of the two flyer payout systems 650 and 660 are driven by a drive unit 450 , coupled here with the respective rotary flyers 300 , 300 ′ and the second strand 103 ′ is drawn out under dancer regulation with nearly constant tensile force. The respective drawn off strands 102 ′ and 103 ′, as described above in detail or will be described below, are rotated with the respective stranding element 100 , 100 ′, which is part of the lower rotary shaft 600 , 600 ′ and subsequently guided over the respective rotary flyer 300 , 300 ′. Through this, through their rotation, they receive a twisting. After this, the strands 102 ′ and 103 ′ are passed to a first stranding point—not shown—and receive a first stranding operation. The product is then passed through a pair stranding assembly, where it receives a second stranding operation when leaving the rotary flyer of this pair stranding assembly. Here, the twisting is either completely or partially twisted back out depending on the back twisting percent or the degree of back twisting present. FIG. 1 shows the stranding element 100 , 100 ′, as it is also employed for back twisting operation. The quadruple dot-dashed line 107 illustrates the path of the strand 102 ′ or 103 ′ through the stranding element 100 , 100 ′ in the case of back twisting. For back twisting, as the path 107 shows, the first 102 ′ or the second 103 ′ strand is passed at the inlet end side 140 through the central inlet 131 into the stranding element 100 , 100 ′ or the lower rotary shaft 600 , 600 ′. The further central passage 130 of the strand 102 ′, 103 ′ runs along the rotational axis 101 of the stranding element 100 , 100 ′ for a predetermined distance, until the strand 102 ′, 103 ′ leaves the stranding element 100 , 100 ′ over a deflection roller 133 via the outlet 132 in the direction of the rotary flyer 300 , 300 ′. Embodiment 3:Regulation of the Strand Tension Embodiment 3 represents a wire or strand tension regulation in the stranding assembly according to the embodiment 1. The described strand tension regulation can however also be the subject of protection alone without the constructive details of the stranding assembly according to embodiment 1. The aim of the following embodiment and description of strand tension regulation is to achieve the same strand tension at the stranding point of the two strands when performing stranding or pre-stranding. The strand tension regulation according to this embodiment should therefore control the different tensions in the two strands, which arise due to the different lengths of the payout paths of the two strands (up to the first stranding point) and the resulting different friction forces on the two strands. For the purposes of strand tension regulation, the two rotary flyer payout systems 650 , 660 are each equipped with a dancer regulator for regulating the drawing of the respective strand, as already described above. Furthermore, the two payout systems 650 , 660 each comprise a device for tensile force measurement or strand tension measurement, in this case a first 700 and a second 701 force sensor, which in drawing direction is arranged directly after the payout position of the respective strand in the corresponding (first and second) rotary flyer payout system 650 660 . The first or the second strand 102 , 103 is passed over the first or second force sensor 700 , 701 and their tensile force or strand tension is measured. In addition, the stranding assembly comprises a further, in this case a third force sensor 710 , which in drawing direction is arranged after the stranding point 200 of the two strands 102 , 103 . The stranded product 220 (out of the first and second strands 102 , 103 ) is passed over this sensor and its tensile force or strand tension is measured. In the following this is referred to briefly as the product tension or product tensile force. In the embodiment of the strand tension regulation, a first dancer-regulated payout of the first strand 102 takes place with a predetermined master or nominal drawing force F(nominal) in the rotary flyer payout system 650 used for tangential payout. The drawing force or strand tension of the first strand 102 is measured directly following the drawing location in the first payout system 650 for adjusting the nominal drawing force of the first strand 102 and for guaranteeing a drawing operation with constant nominal drawing force. The drawing force is measured and correspondingly adjusted (F(nominal)=F(payout 1)) or readjusted (automatically during operation). In addition, the product tension or tensile force F(product) of the (pre-)stranded product 220 is measured by means of the third force sensor 710 . The drawing force F(payout 2) for the second, dancer-regulated payout of the second strand 103 of the second rotary flyer payout system 660 , also used for tangential payout, is then determined as follows: F (payout 2)= F (nominal)−(product tension−2× F (nominal)).  (Eq. 1) This determined drawing force for the second strand 103 is then set for the dancer-regulated payout of the second payout system 660 and, analogously with the first payout system 650 , is monitored by the second force sensor 701 and optionally (automatically during operation) adjusted or readjusted. The following numerical examples illustrate the strand tension regulation. A nominal drawing force of F(nominal)=10 N is set at the first dancer regulated payout of the first payout system 650 . The force measurement by the third force sensor 710 delivers, for example, a product tensile force of F(product)=27 N. According to the above equation (Eq. 1), a drawing force for the second, dancer-regulated payout of the second strand 103 F(payout 2)=3 N is determined. The second strand 103 is then drawn out with this drawing force F(payout 2)=3 N. This in return results in F(product)=20 N. These adjustments of the first and second drawing force with F(payout 1) or F(nominal) and F(payout 2) make for uniform strand tension when stranding and therefore a qualitatively higher value product. The drawing force for the second strand 103 is varied (reduced) until the value of 2×F(nominal) results for the product tension. Finally, it should again be mentioned that the described assembly is highly flexible, due to the different application possibilities (stranding, back twisting, tension regulation). A fabrication of strand pairs for UTP, FTP, STP and S/STP for the categories 5, 5+, 6 and possibly 7 can be increased by more than 30%. The application as a normal back twisting unit or assembly (embodiment 2) for high value products, such as category 8, four-fold and bus lines is also possible, as is a main stranding with back twisting of 0 to 100%.

A stranding of long winding material using a substantially cylindrical rotary body. The rotary body includes a first passage for guiding a first winding material through the cylindrical rotary body and a second passage for guiding a second winding material through the cylindrical rotary body. The first passage connects a first offset inlet on a first end side of the rotary body to a first offset outlet on a second end side of the rotary body, which opposes the first end side. The second passage connects a second input, arranged on a surface of the rotary body extending between the two end sides, to a second offset output on the second or first end side of the rotary body.

FIELD OF THE INVENTION AND RELATED ART The present invention relates to an image or picture display apparatus used for preparation of a document and display of the prepared document, and more specifically to a picture display apparatus capable of displaying a picture substantially equal to a picture printed out therefrom. Hitherto, a document preparation system including a data processing apparatus, such as a word processor or a personal computer, to which a printer is connected, has been used at offices or in the home. In case of preparing documents by using such a system, it has been a general practice to prepare a document by a data processor while checking its form or style on its display, and print out the prepared documents by a printer. However, such a conventional system has included a data processor display and a printer that exhibit remarkably different degrees of resolution. Accordingly, there results in a difference between a font on a display and a font printed out by a printer, so that a sentence displayed in one row on a display can be printed out in two rows in some cases. Further, in case where a photographic image is printed out as a document, some picture processing, such as enlargement or size reduction, is required accompanying the resolution difference. But in such a case, a deviation of several dots can occur depending on the image size and the ratio of enlargement/reduction, so that a photographic image displayed in one page on a display can be printed out in two pages in some cases. In such a case where a displayed document and a corresponding printed-out document are deviated from each other, it becomes necessary to re-correct the document after printing out the document, thus encountering much difficulty in getting a desired document and wasting considerable amount of paper and time for printing out. Some data processors have the capability of displaying an image to be printed out (hereinafter called a “printed-out image”) before the actual printing-out thereof, but as the display resolution is inferior to the printer resolution, the printed-out image cannot be displayed in detail, so that the above difficulty has not been solved as yet. On the other hand, as the resolution of a printer becomes higher, a higher-definition display apparatus is desired. A liquid crystal panel has been used as a high-definition display apparatus for a data processor, and compared with a conventional liquid crystal panel having a definition on the order of 1600×1200, a liquid crystal panel having a higher definition (e.g., 20000×2000 or higher) is desired. It has been a general practice that a high-definition liquid crystal panel requires display ICs, and an OS or an application software for a data processor adapted for such a high-definition use. Even if display ICs adapted for a high-resolution display are used, there may be encountered a difficulty that small characters become difficult to read if general-purpose application software is used. SUMMARY OF THE INVENTION A principal object of the present invention is to provide a picture display apparatus capable of reducing troubles in preparing a document to be printed and minimizing waste paper or time during the document preparation. Another object of the present invention is to provide a picture display apparatus for displaying a document to be printed, capable of allowing a high-definition picture display without using ICs specifically adapted for high-resolution display. Another object of the present invention is to provide a picture display apparatus capable of obviating a lowering in display quality when multi-purpose application software is used. According to the present invention, there is provided a picture display apparatus, comprising: a data input means for inputting document data, a printer adapted for connection with the data input means so as to print out a picture based on the document data, and a picture display means connected to the data input means for displaying a picture based on the document data. The picture display means is adapted for displaying a picture that is substantially identical in shape and resolution to the picture to be printed out by the printer. According to another aspect of the present invention, there is provided a picture display apparatus, comprising: data output means for outputting picture data for hard copies, a picture display means for displaying a picture based on the picture data, and a data conversion means disposed between and connected to said data output means. The picture display means converts the picture data outputted from the data output means into data adapted for display by the picture display means. These and other objects, features and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of a high-definition display system according to a first embodiment of the invention. FIG. 2 is a block diagram for illustrating an entire organization of the high-definition display system. FIG. 3 is a flow chart for illustrating a function of the system. FIGS. 4A and 4B are an illustration and a flow chart, respectively, of a procedure for converting RGB luminance data to density data. FIG. 5 illustrates an organization of print data transmitted from a data processor 2 to a high-definition display apparatus 3 . FIGS. 6A-6K illustrate organization of respective commands in the print data. FIG. 7 is an illustration of a printed image together with denotation of respective commands in the print data. FIG. 8 is a flow chart for illustrating operation inside the high-definition display apparatus 3 . FIGS. 9A and 9B are an illustration and a flow chart, respectively, of a procedure for converting RGB luminance data to density data according to another embodiment. FIG. 10 is a flow chart for illustrating operation inside the high-definition display apparatus 3 according to another embodiment of the invention. FIG. 11 is a schematic illustration of an entire organization of another embodiment of the picture display apparatus according to the invention. FIGS. 12A and 12B illustrate an A-type display apparatus. FIGS. 13A and 13B illustrate a B-type display apparatus. FIG. 14 is a block diagram for illustrating a structure of page controller. FIGS. 15 and 16 illustrate respective registers. FIG. 17 is a flow chart for illustrating the operation of a page controller 5 . FIGS. 18 and 19 are respectively a flow chart for illustrating data read operation. FIGS. 20A and 20B illustrate structures of page data and line data. FIGS. 21A and 21B illustrate a method of elongating raster data. FIG. 22 is a flow chart for illustrating data output organization. FIG. 23 illustrates an organization of output data. FIG. 24 illustrate an example of display state on the display apparatus 3 . DESCRIPTION OF THE PREFERRED EMBODIMENTS Now, a first embodiment of the present invention will be described. As shown in FIG. 1, a picture display apparatus 1 according to this embodiment includes a data input means 2 to which document data is inputted. The data input means 2 is designed to be connected to a printer for printing out a picture or image based on the document data. The data input means 2 is further connected to a picture display means 3 for displaying a picture based on the display data. The displayed picture is almost equal to the picture to be printed and is designed to be displayed at a resolution almost equal to that of the printer. The data input means 2 may for example comprise a personal computer or a word processor. The above-mentioned document data includes at least luminance data. The data input means 2 includes a picture processing unit 10 as an input-side data conversion unit for converting the luminance data into density data, so that the density data will be transmitted from the data input means 2 to the picture display means 3 . The picture display means 3 includes an output-side data conversion unit 21 and a picture display unit 23 , so that the density data is re-converted into luminance data by the output-side conversion unit 21 and a picture based on the luminance data is displayed on the picture display unit 23 . The data input means 2 may include an N-value-processing unit 11 for coding the density data into N-level values or into numbers according to a numeration system with a radix of N (N being a natural number of at least 2), e.g., binary (digit) values, so that the number of gradation levels displayed at the picture display unit 23 will be changed in the picture display means so as to correspond to the N-level coded values in the N-value processing unit 11 . The luminance data may comprise RGB-three-color luminance data, while the density data may comprise YMCK-four-color density data or YMC-three-color density data. The picture display unit 23 may be designed to display a picture substantially identical to the one to be printed out and also display a form of paper for the print-out. The picture display unit 23 may preferably comprise a high-definition liquid crystal device, which may preferably comprise, e.g., a simple matrix-type liquid crystal device using a liquid crystal showing ferroelectricity (hereinafter simply called “FLC”). The picture display apparatus according to this embodiment may be operated in the following manner. When document data including luminance data is inputted to the data input means 2 , the luminance data is converted into density data, and the converted density data is supplied to the picture display means 3 , where the density data is re-converted into luminance data to display a picture substantially identical to a picture to be printed out. According to this embodiment, the picture display means 3 displays a picture substantially identical to the one to be printed out, so that it is possible to prepare a document while observing the picture on the display means 3 and confirming the style and appearance thereof. Accordingly, a printing-out operation for confirming the appearance of the document becomes unnecessary, thus being able to obviate the waste paper and time for the printing-out. This embodiment will be described more specifically. As shown in FIG. 1, an (ultra-)high-definition display system (picture display apparatus) 1 , includes a data processor (data input means) 2 , such as a personal computer or a word processor, to which document data is inputted, and an (ultra-)high-definition display apparatus (picture display means) 3 , so that a document can be prepared while confirming the style and appearance thereof on the high-definition display apparatus 3 . The data processor 2 is designed so that a printer is connected thereto as desired for printing out a picture based on the document data (i.e., the document). FIG. 2 is a block diagram for illustrating an entire organization of the high-definition display system 1 . As shown in FIG. 2, the data processor 2 is equipped with application software 5 for writing or word processing, an input unit 7 corresponding to a mouse device, a keyboard (or a means for receiving document data via a network) and a display unit 8 , so that the application software 5 , the input unit and the display unit are controlled by an operating system 6 . The data processor 2 is further equipped with a display control unit 12 for preparing data (“print data” which will be described in further detail hereinafter) to be supplied to the high-definition display apparatus 3 , and the display control unit 12 includes a picture processing unit 10 for processing the document data to provide density data, an N-value processing unit 11 for coding the density data into N-level digit values, and a control unit 9 for controlling the units 10 and 11 . Further, as shown in FIG. 4A, the picture processing unit 10 includes a density conversion unit (input-side data conversion unit) 15 for converting RGB-luminance data (luminance signals according to the NTSC (National Television System Committee) system further converted into numerical values) into C, M and Y-density data, a UCR (Under Color Removal) unit 17 for removing a gray component from the density data C, M and Y, respectively, as an under color (or ground color), a black generation unit 16 for adding density data K corresponding to the gray component, and a γ-conversion unit 18 for effecting γ-conversion, (details being described hereinafter.). Further, the high-definition display apparatus 3 integrally includes a control unit 20 for controlling the entirety of the apparatus, a conversion unit (output-side conversion unit) 21 for effecting various controls based on print data from the data processor 2 and a display unit (picture display unit) 23 for displaying print image. The display unit 23 may comprise, e.g., a simple matrix-type liquid crystal panel of high resolution (a display density of ca. 300 dpi) using FLC. Further, a printer (not shown) for receiving and printing out the density data may be connected to the data processor 2 in parallel with or via the display apparatus 3 . For the printer interface, it is possible to use Centronics I/F or RS232C Serial I/F. Next, an operation for displaying a print image (which is a high-resolution picture) on the display unit 23 of the high-definition display apparatus 3 will be described with reference to FIGS. 3-8. FIG. 3 is a flow chart for illustrating a function of the system. FIGS. 4A and 4B are an illustration and a flow chart, respectively, of a procedure for converting RGB luminance data to density data. FIG. 5 illustrates an organization of print data transmitted from a data processor 2 to a high-definition display apparatus 3 . FIGS. 6A-6K illustrate organization of respective commands in the print data. FIG. 7 is an illustration of a printed image together with denotation of respective commands in the print data. FIG. 8 is a flow chart for illustrating operation inside the high-definition display apparatus 3 . [1] Operation of the Entire System When a person for operating the system 1 (hereinafter called an “operator”) inputs document data by using the input unit 7 of the data processor 2 (FIG. 3, S 1 ), a print image (a picture or image substantially identical to a picture or image formed by printing) is displayed on the display unit 23 of the display apparatus 3 (FIG. 3, S 4 ). At this time, the shape of paper for printing is also displayed (as will be later described in further detail). After confirming the document appearance based on the print image on the display unit 23 , the operator can correct the document data (FIG. 3, S 2 ), if desired. If the document data is corrected, the corrected print image is displayed on the display unit 23 (FIG. 3, S 4 ). The system 1 is further designed to effect some control for adjusting the number of colors of print image to the number of colors of original data, such as a photographic image, so that the color of the print image is close to that of the original data (detail being described later), and also a halftone processing. In the system 1 , the halftone processing method may be selected from various halftone processing methods, such as the error diffusion method and the pattern dither method, as desired by the operator, and depending on the selected method, a halftone-processed print image is displayed on the display unit 23 (FIG. 3, S 4 ). In the above-described steps, the input and/or halftone designation steps may be omitted or skipped, if these steps are unnecessary. On the other hand, other steps for designation of other items may be added, if necessary. [2] Detail of Each Operation [2-1] Operation of the Data Processor 2 When the operator inputs document data including RGB luminance data, the RGB luminance data is inputted to the picture processing unit 10 via the operating system 6 (FIGS. 4A and 4B, S 10 ). Then, the RGB luminance data may be subjected to non-linear conversion, such as logarithm conversion, into density data C, M and Y (FIGS. 4A and 4B, S 12 ). Then, the CMY density data is subjected to the under color removal (UCR) and black generation by the UCR unit 17 and the black generation unit 16 according to the following formulae (FIGS. 4A an 4 B, S 14 ): C ( 1 )= C−β× MIN ( C, M, Y ) M ( 1 )= M−β× MIN ( C, M, Y ) Y ( 1 )= Y−β× MIN ( C, M, Y ) K ( 1 )=α×MIN ( C, M, Y ), wherein MIN (C, M, Y) denotes a minimum value among three density data C, M and Y; β denotes a proportion of the under color removal with respect to MIN (C, M, Y); and α denotes a proportion of black generation. Then, at the γ-conversion unit 18 , the resultant density data C( 1 ), M( 1 ), Y( 1 ) and K( 1 ) are subjected to adjustment of output gamma (γ-conversion) into data C( 2 ), M( 2 ), Y( 2 ) and K( 2 ), respectively (FIGS. 4A and 4B, S 16 ), so that the resultant signals of the data C( 2 ), M( 2 ), Y( 2 ) and K( 2 ) will satisfy a linear relationship with respective densities of a picture displayed on the display unit 23 corresponding thereto. These data C( 2 ), M( 2 ), Y( 2 ) and K( 2 ) are multi-value data and are coded into N-level values by the N-value processing unit or N-value coder 11 , thereby providing data C′, M′, Y′ and K′ (FIGS. 4A and 4B, S 18 ). As a result, print data is supplied to the high-definition display apparatus 3 via the controller. As shown in FIG. 5, the print data is composed of respective commands of “PAGE START”, “RESOLUTION”, “FORMAT”, “PAPER SIZE”, “MARGIN”, “RASTER DATA”, “RASTER SKIP” and “PAGE END”. The respective commands will now be described. “PAGE START”: As shown in FIG. 6A, this command is composed of characters “SC” representing a start of command and a command species code of “00”, thereby meaning a start of transfer of print data. “RESOLUTION”: As shown in FIG. 6B, this command is composed of “SC”, a command species code of “01”, a vertical resolution and a lateral (or horizontal) resolution, thereby designating the resolutions in vertical and lateral directions of print image. “FORMAT”: As shown in FIG. 6C, this command is composed of “SC”, a command species code of “02”, and a bit length (i.e., a value of N in N-level value coding, wherein N=2, 3, 4, . . . ). “PAPER SIZE”: In the case of displaying a print image on the display unit 23 , it is preferred to also display a paper shape with an image, and for this purpose, it is necessary to input data regarding the paper size into the high-definition display apparatus 3 . This command is for designating the paper size (more specifically, a paper length or height ( 30 in FIG. 7) and a paper width ( 31 in FIG. 7) and is composed of “SC”, a command species code of “03”, a paper length, and a paper width. The paper shape is displayed on the display unit 23 in a state of being centered with a central point of the display unit 23 as the center regardless of the paper size. “MARGIN”: As shown in FIG. 6E, this command is composed of “SC”, a command species code of “04”, a top margin, a bottom margin, a left margin and a right margin and is used, as shown in FIG. 7, for designating a top margin 33 (a width of blank region for not being printed with characters, etc., along an upper edge of paper), a bottom margin (a width of blank region along a lower edge of paper), a left margin (a width of blank region along a left edge of paper) and a right margin (a width of blank region along a right edge of paper). “LASTER DATA (Y)”: As shown in FIG. 6F, this command is composed of “SC”, a command species code of “10”, a data length and Y-data. Herein, a “raster” refers to a row of dots along a lateral scanning at a portion of paper 38 except for the left margin 35 and the right margin 36 . In the system 1 , density data is supplied from the data processor 2 to the high-definition display apparatus 3 as described above, and one raster is composed separately for each of Y, M, C and K components for time-sequential designation. This command is used for designating Y-component density data, etc., of an objective raster. Incidentally, Y-data may have been subjected to data compaction, such as Pack Bits according to the TIEF format. In this case, the data length refers to a compacted data length. “RASTER DATA (C)”: As shown in FIG. 6H, this command is composed of “SC”, a command species code of “12”, a data length and C-data and is used for designating C-component density data, etc., of an objective raster. “RASTER DATA (K)”: As shown in FIG. 6I, this command is composed of “SC”, a command species code of “13”, a data length and K-data and is used for designating K-component density data, etc., of an objective raster. “RASTER DATA (K)”: As shown in FIG. 6I, this command is composed of “SC”, a command species code of “13”, a data length and K-data and is used for designating K-component density data, etc., of an objective raster. “RASTER SKIP”: For example, in case where there occurs a number of rasters requiring no writing as represented by a blank row spacing 39 between character rows as shown in FIG. 7, YMCK components do not occur for these rasters. In such a case, the above-mentioned raster data are not sent for these rasters, but only data concerning the number of such rasters is supplied, whereby the number of rasters are skipped on the high-definition display apparatus 3 . As shown in FIG. 65, this command is composed of “SC”, a command species code “20” and a skip number, thereby designating the number of rasters to be skipped. “PAGE END”: As shown in FIG. 6K, this command is composed of “SC” and a command species code “99”, thereby representing the end of print data transmission. [2-2] Operation of the High-definition Display Apparatus 3 On receiving the print data (FIG. 8, S 20 ), the high-definition display apparatus 3 analyzes what command is received thereby (FIG. 8, S 22 ). In case where the received command is “PAGE START”, the page is initialized (FIG. 8, S 24 ), default values are set to respective set value items. More specifically, the item of resolution is set with the resolution of the high-definition display apparatus 3 , the item of format is set with a number of bits that can be displayed by one pixel of the high-definition display apparatus 3 , and the items of paper height and width are set with the values regarding the display region (i.e., number of sub-scanning lines and number dots along a main-scanning line, or numbers of scanning lines and data lines for defining the display region) of the high-definition display apparatus 3 while setting all the top, bottom, left and right margins at zero. Further, the RGB luminance data are respectively made the maximum to clear the set paper region. If the received command is any of “PAPER SIZE”, “RESOLUTION”, “FORMAT” AND “MARGIN”, the respective set values are changed from the default values to the designated values (FIG. 8, S 26 ). Now, if the designated value of resolution does not agree with the resolution of the high-definition display apparatus 3 , a resolution conversion is effected by size enlargement/reduction. If the bit length B 0 designated by “FORMAT” does not agree with the bit length B 1 per one pixel of the high-definition display apparatus 3 , the bit length is adjusted by the conversion unit 21 in the following manner. In case of B 0 >B 1 ; D 1 =D 0 >>( B 0 −B 1 ). In case of B 0 <B 1 ; D 1 =D 0 <<( B 1 −B 0 ). In the above, D 1 denotes display data, D 0 denotes input data (i.e., print data), and >> and << denote N bit shift for obtaining D 1 by shortening and elongating, respectively, of the input data D 0 by |B 0 −B 1 | bit. If the designated size is larger than the display region of the high-definition display apparatus 3 , the display region per se is adopted as the paper size, and the set values of resolution, format and margin are changed. If the received command is “RASTER DATA (Y)”, “RASTER DATA (M)”, “RASTER DATA (C)” or “RASTER DATA (K)”, the conversion unit 21 converts the density data YMCK into RGB luminance data to prepare page data (FIG. 8, S 28 ). R=˜C G=˜M B=˜Y R=G=B=˜K, wherein “˜” represents inverting from density data (C, M or Y) into complementary luminance data (R, G and B), and the last formula of R=G=B=˜K means that the inverted value of K is allotted to identical levels of complementary luminance of R, G and B. If the received command is “RASTER SKIP”, the designated skip number of rasters are skipped to prepare page data (FIG. 8, S 28 ). The skip number may be adjusted depending on the resolution so that the print image is not affected by the resolution. If the received command is “PAGE END”, the page data is displayed on the display unit 23 (FIG. 8, S 30 ). It is possible to modify the above embodiment so that the picture processing unit 10 is not provided with the UCR (under color-removal) unit 17 or the black generation unit 16 (FIG. 4A.) but is designed to convert RGB luminance data into density data of only three colors of YMC. FIGS. 9A and 9B illustrate this modification of luminance-density conversion in comparison with FIGS. 4A and 4B. Corresponding to this modification, the three-color density data is supplied from the data processor 2 to the high-definition display apparatus 3 , wherein the density data is re-converted into RGB luminance data (FIG. 10 ). Next, a second embodiment of the present invention will be described, wherein document data (print data) as picture data for printing out hard copies is prepared by a data processor, such as a personal computer, and a picture based on the picture data is displayed on a specific high-definition display apparatus by using a specific data page control means. Referring to FIG. 11, a picture display apparatus 100 according to this embodiment includes a data output means 102 for preparing and outputting picture data for hard copies, and a picture display means 103 for displaying the picture data, which are connected via a data conversion means (a page controller) 105 for converting the picture data for hard copies into data suitable for display on the picture display means 103 . More specifically, by the data conversion means 105 , the picture data for hard copies is rearranged into data suitable for display on the picture display means 103 . If desired, the data conversion means 105 may be disposed on the picture display means 103 and particularly integrally with a display unit in the picture display means 103 . In this embodiment, the picture data for hard copies may for example be composed of YMC color data, and the YMC color data may be converted into RGB color data (or luminance data) by the data conversion means 105 . The picture display means 103 may preferably be one having a resolution of 200 dpi or higher, e.g., a liquid crystal display panel. According to this embodiments, document data for printing can be optimally displayed on a high-definition display means by function of the data conversion means and without using display driver ICs on the display side, or specific OS or application software on the data processor side. Now, this embodiment will be described more specifically. Referring to FIG. 11, a picture display apparatus 100 includes a personal computer (PC-AT) 102 (as a data processor or a data output means), and a display apparatus 103 (as a picture display means) including a liquid crystal display panel as a display unit. The data output means ( 102 ) in this embodiment refers to a means for converting data inputted by an operator into picture data for hard copies as document data and outputting the picture data to the picture display means ( 103 ) and substantially corresponds to the data input means ( 2 ) in the previous embodiment. The display apparatus 103 may for example comprise a liquid crystal display panel composed of FLC (ferroelectric liquid crystal) and a color filter having a resolution of ca. 300 dpi. The display apparatus 103 may be either one illustrated in FIG. 12 (hereinafter referred to as “A-type”) or one illustrated in FIG. 13 (hereinafter referred to as “B-type”). In the apparatus 100 , one of the A-type and B-type apparatus may be designed for use by a push button SW (described later). In the A-type display apparatus shown in FIG. 12A, 2 pixel rows are constituted by adjacent 3 scanning lines. More specifically, R and G color filter segments are alternately disposed along a first scanning line, B and R color filter segments are alternately disposed along a second scanning line, and G and B color filter segments are alternately disposed along a third scanning line, so that one pixel is composed of R and G segments along the first scanning line and a B segment along the second scanning line, and another one pixel is composed of an R segment along the second scanning line and G and B segments along the third scanning line. On the other hand, in the B-type display apparatus, one pixel row is composed of adjacent 2 scanning lines. More specifically, R and G color filter segments are alternately disposed along a first scanning line, and B color filter segments are disposed in succession along a second scanning line, so that one pixel is composed of R and G segments along the first scanning line and two B segments along the second scanning line. On the other hand, as shown in FIG. 14, the page controller 105 includes a CPU 110 , an FPG 111 , an SDRAM 112 , a flash ROM 113 , a program ROM 114 , a line buffer 115 , a centronics interface 116 connected to a centrocontroller 120 of the FPGA 111 , a display side interface (I/F) 118 connected to the FPGA 111 via a differential driver 117 , etc., and a system clock 119 . The page controller 105 has functions of, e.g., converting page data (picture data) read thereinto from the personal computer 102 into data for the display apparatus 113 , memorizing data for 9 pages and causing the display apparatus 103 to disclose a picture based on one data among the 9 page data according to the instruction of the operator, and defining an area 130 of a prescribed width along a right edge of a display screen or display area (hereinafter called a “thumbnail area”) and displaying pictures for the above-mentioned 9 pages (each at a {fraction (1/10)} size) at the thumbnail area 130 . The display/non-display or picture exchange at the thumbnail area can be designated by a push button SW (described later). In a specific example, “SH2 (SH7604)” was used as the CPU 110 , including a DRAM controller, DMA and RS232C (for indicating an operation state on the personal computer 102 ) as internal devices. As the EPGA 111 , “ALTERA 9560” (available from Altera Co.) was used. DRAM 112 was used at 32 bit width and at CS 2 region and CS 3 region for storing 5 page data sent from Centronics interface 116 . The flash ROM 113 was composed of 8 flash ROMs of 2 MB and was used at 32 bit width and at CS 1 region. The flash ROM 113 was used for storing frame data (for 4 pages) copied from the line buffer 115 . The line buffer 115 was composed of two SRAMs functioning as the line buffers for A-line and B-line which were switched therebetween by LINE AB register shown in FIG. 15 (as described later in detail). Each SRAM had a capacity of 2 KB (for expected capacity in use of 800 B+α) and was composed of 16 bit width. The centronics interface 116 was connected to the personal computer 2 and designed to be adopted to timing of a single-direction centro and high-speed transfer mode. The system clock 119 was operated at 20 MHz. The program ROM was composed of 128 KB—EPROM and used at 16 bit width and CS 0 region. In the program ROM 114 , a control program was stored, and after checking the operation of DRAM 112 (after the initial setting operation), the program was sent to DRAM to be executed at DRAM 112 . The page controller 105 had 4 push buttons SW, which were used to designate a type of the display apparatus 103 (i.e., either one of A-type and B-type mentioned above), and designate whether a test pattern mode or not. The page controller 105 further had one reset switch (RESET). The page controller 105 further included POWER LED turned on when a power switch was turned on, DATA IN LED turned on when STROBE signal was supplied via the centronics interface 116 , and DATA OUT LED turned on when line data was outputted to the display apparatus 103 . Registers used in this embodiment will be described with reference to FIGS. 15 and 16. LEDPORT is for ON/OFF of LED so that LED is ON at “1”; PUSHSW is for input to a push button SW; DIPSW is for input to a push button SW; CENTRODATA is for reading data from the centronics interface 116 and is also used for DMA; and CENTROCONT is for controlling the centronics interface 116 so that a sum of soft BUSY and hard BUSY is outputted to the outside. Further, SERIALCONT is for control of RS232C, whereas Txd, and Rxd utilize inner functions of CPU; LINE AB is for exchange between A and B lines so that “0” represents A-line is on the CPU side and B-line is on the output side. ATYPER, ATYPEG and ATYPEB are for data conversion inputs when the A-type display apparatus is used; ATYPE 1 , ATYPE 2 and ATYPE 3 are for data conversion outputs when the A-type display apparatus is connected; BITFLIP is for exchanging LSB and MSB in bit row; TATEYOKO 1 , TATEYOKO 2 , TATEYOKO 3 and TATEYOKO 4 are for turning a picture by 90 deg. when page data is converted into line data. LINECONT is for line control, and the detail function thereof will be described later with reference to FIG. 22 . The operation of this embodiment will now be described. The operation of the page controller 105 is described by outline at [1] and details of each operation is described at [2]. [1] Outline of the Operation of the Page Controller 105 (FIG. 17) Referring to FIG. 17, when a power switch is turned ON (FIG. 17, PON) or a reset switch is turned ON (RST), an initialization sequence is effected (S 101 ), including turning-ON of POWERLED (LED), memory checking, and reading of dip switch set values (Dip SW). On the other hand, when page data is inputted from the personal computer 102 via the interface 116 (S 102 ), the page controller 105 analyzes the page data (S 103 ) and effects data conversion to prepare frame data and thumbnail data (S 104 , S 105 ). The prepared frame data is transferred to the DRAM 112 where data for 5 pages is stored, and data for 4 pages is transferred to the flash ROM 113 to be stored at the flash ROM 113 (S 106 ). Further, to the frame data, thumbnail data, cursor data (i.e., data for displaying a cursor on the screen), etc., are added, to prepare line data (S 107 ). Thereafter, the line data is sequentially outputted to the display apparatus 103 (S 108 ). Incidentally, if a timer (PTM) counts a prescribed time, a refresh operation is performed (S 109 ), a frame data identical to the one displayed immediately therebefore is prepared again (S 107 ), a line data corresponding thereto is outputted (S 108 ). Further, if a switch input is present by a switch (SW) operation (S 110 ), a command corresponding to the operated switch is generated (S 111 ), and data corresponding to the operated switch is generated (S 111 ), and data corresponding to the command is prepared (S 107 ). For example, if a test pattern mode is instructed by the switch operation (S 110 , S 111 ), a test pattern is prepared (S 112 , S 107 ), and displayed on the display apparatus 103 . [2] Detail of Each Operation (FIGS. 21-24) [2-1] Data Reading In data reading, transfer is performed by utilizing DMA (direct memory access) function of CPU 110 . In some cases, data for plural pages is read, so that DMA is performed while maximizing the receiving buffer size, and if data to be transferred is left without completing DMA, the conversion of page data is performed to empty the receiving buffer and then subsequent DMA is performed. In this instance, the CPU 110 is placed in a waiting state during the conversion of page data. In data reading, first, a flag is initialized (FIG. 18, S 120 ) to set a timer at, e.g., 30 sec. Then, input of page data is awaited (S 112 , S 129 ), and if page data is inputted, the data is read (S 112 , S 123 ) to make the flag “1” (S 124 ). In case where a key is pushed during the input of such page data, the processing is interrupted and the inputted page data is discarded (S 125 ). When no key is pressed during the page data input and if the read data is not for the final page (i.e., if the page end command FF is not detected), the time is again set to wait for data input (S 126 , S 121 , S 129 and S 130 ), and data is read (S 123 ) if data is inputted during the set time, or this processing is terminated in case of no data input during the set time. On the other hand, if the read data is for the final page (i.e., if the page end command FF is detected), the already inputted one page data is converted into line data (S 127 , detail being described later), and the flag is made “2” (S 128 ). In case where page data for the next page is inputted (S 122 ) before the flag is made 2 (i.e., during the conversion into line data), the page data reading, etc., is performed similarly as above (S 122 , S 123 ), but if no page data is inputted, the processing is terminated (S 122 , S 129 ). Detail of the above-mentioned data reading (FIG. 8, S 123 ) will now be described with reference to FIG. 19 . For data reading, the time is set to, e.g., 1 sec. (FIG. 19, S 140 ), an address register, etc., in DMA register in CPU 110 are set (S 141 ), a STROBE signal is sent to the centronix interface 116 to wait until STROBE flag in CENTROCONT becomes Low (S 142 ). When STROBE flag becomes Low, BUSY flag in CENTROCONT is made High (S 143 ) whereby STROBE is made High to start data transfer, so that the data is latched and BUSY flag is made low. Then, DREQ flag in CENTROCONT is made High (S 144 ), and data is read into DMA controller (S 145 ). The data reading is repeated until the number of reading times set in DMA is reached (S 146 ), and if the data reading is completed, BUSY flag is made Low (S 147 ). At this time, if DREQ in CENTROCONT is High, one data is still present and is therefore read, and then the processing is terminated (S 151 ). Incidentally, in case where the number of read data is fewer than the number of reading times set in DMA, a timer interruption is caused (S 149 ), BUSY flag is made Low even if the data reading is not completed, and the processing is terminated (S 147 ). At this time, if DREQ in CENTROCONT is High, one data is still present and is therefore read, and then the processing is terminated (S 151 ). [2-2] Data Conversion (FIG. 17, S 104 ) [2-2-1] Structure of Page Data Before Conversion, and Structure of Time Data After the Conversion As described above, page data is inputted from the personal computer 102 via the Centronics interface 116 . The page data is composed of raster data for hand copies comprising YMCK-color data, and various command data for indicating position of raster data, etc. As for raster data among these, as shown in FIG. 20A, color data for 4 colors of YMCK are arranged respectively laterally, a set of 4 color data constitutes one raster data, and the raster data is arranged vertically in 3200 row for 3200 rasters. The leading raster data is data regarding an uppermost line on a display, such as a CRT screen, and includes data from its left end to right end in that order. On the other hand, the line data is composed of three colors of RGB. The data are arranged vertically and the lines are arranged laterally. The direction of data arrangement is from the bottom to the top. [2-2-2] Operation of Data Conversion Page data is converted into line data according to the following manner. Thumbnail data is prepared through a similar conversion, but page data is reduced to {fraction (1/10)} in advance of the conversion. (1) Data Elongation Raster data is in a compacted state, e.g., as shown in FIG. 21A so that it is elongated. More specifically, if a leading first byte data N is in the range of 0≦N≦127, N+1 data from those of the second byte to N+1-th byte are made raster data as they are so that the second byte data constitutes the leading data. FIG. 21A shows a case of N=2 satisfying 0≦N≦127, so that 4 (sets of data) including those of 2nd byte to 5th byte (A, B, C, D) are made raster data as they are (FIG. 21 B). In contrast thereto, if a leading data N is in the range of −127≦N≦−1, a subsequent data is copied for −N+1 bytes to provide raster data, so that the second byte data is made the leading data. FIG. 21A shows a case of N=−2 (satisfying −127≦N≦−1), so that the subsequent data “Z” is copied for −(−2)+1=3 bytes to provide raster data of “E, E, E” (FIG. 21 B). (2) Conversion of YMCK Color Data into RGB Color Data The data conversion is performed by ignoring K data and making complements of Y data, M data and C data to provide B data, G data and R data, respectively. (3) 90 deg. Conversion Data direction and line direction are mutually converted by using TATEYOKO register. (4) Data Rearrangement Referring to FIG. 16, the rearrangement is performed by writing data into respective registers of REARRANGEMENT R, REARRANGEMENT G and REARRANGEMENT B and reading out data from the respective registers of REARRANGEMENT 1 , REARRANGEMENT 2 and REARRANGEMENT 3 , respectively. For reference, regarding the register of REARRANGEMENT R (ATYPER), for example, numbers represent a pixel position before rearrangement, including a left numeral representing a common electrode and a right-numeral representing a segment electrode. FIG. 16 illustrates rearrangement registers for only the A-type display apparatus, but similar register are provided also for the B-type display apparatus, and the rearrangement may be performed similarly by rewriting and reading of data. [2-3] Operation of Data Output Line data output operation is described with reference to FIG. 22 . In order to output line data, ENABLE flag of LINECONT register is made ON to start a line output circuit (FIG. 22, S 160 ) and set a timer to, e.g., 200 msec (S 161 ), whereby line data is written into a line buffer 115 (S 162 ). When the output is completed and END flag of LINECONT register is made High (S 163 ), ERR flag is checked, and if the flag is High (S 164 ), Low of BUSY flag in LINECONT register is awaited (S 173 ) and then OUT flag of the register is made High (S 174 ). Further, in case where ERR flag is Low, LINEAB register is operated to invert the line buffer 115 up-side down (S 165 ), and after waiting for Low of BUSY flag of LINECONT, OUT flag is made High to output line data (S 166 , S 167 ). The inversion of the line buffer 115 may be performed by changing LINEAB flag from “0” to “1” or from “1” to “0” depending on the initial state is “0” or “1”. Line data is outputted (transferred) at a 16 bit width by 10 MHz clock signals. Line data is converted into differential signals by a differential driver and then outputted as such differential signals. The outputted line data are provided with common address by an address counter 123 as shown in FIG. 23 and outputted together with the common address. Then, when all line data are outputted and END flame is checked, and if the flag is High (S 170 ), Low of BUSY flag of LINECONT register is awaited and then OUT flag of the register is made “High” (S 175 , S 176 ). On the other hand, if ERR flag is Low, ENABLE flag of LINECONT register is made Low to complete the processing (S 170 , S 171 , S 172 ). In case where a timer interruption is caused (S 170 ) during the operation, an error LED is turned on to complete the operation (S 181 , S 182 ). [2-4] Display on the Display Apparatus FIG. 24 illustrates an example of display state on the display apparatus 103 , wherein a thumbnail area is defined along a light-side region (i.e., a region 3450-th to 3839-th common lines of the type display apparatus, or a region of 4600-th to 5119-th common lines of the B-type display apparatus) in a display area. The change from a display state to a non-display state or from a non-display state to a display state of the thumbnail area may be effected by rewriting the region while transferring line data for only the corresponding lines. In case where the thumbnail area is placed into display state, the rewriting is sequentially performed from a larger common address line (3839-th common line for A-type; or 5119-th common line for B-type) to a smaller common address line (3450-th common line for A-type; or 4600-th common line for B-type) so that the thumbnail area appears in the direction of arrow (display). On the other hand, in case where the thumbnail line is placed into a non-display state, the rewriting is sequentially performed from a smaller common address line (3450-th common line for A-type; or 4600-th common line for B-type) to a larger common address line (3839-th common line for B-type) so that the thumbnail area disappears in the direction of arrow (non-display) in FIG. 24 . Further, in case of cursor movement for local selection on the screen, line data for only the lines where a picture is rewritten accompanying the cursor movement is selectively transferred, to selectively rewrite the corresponding portion.

A high-definition display apparatus, such as a picture display, having a resolution at a level similar to that of a printer is connected to a data processor, such as a personal computer, to constitute a picture display apparatus, thereby displaying a document under preparation at a resolution level identical to that of the printer. As a result, an operator can confirm the style and appearance of a document under preparation to be printed on a real-time basis on the display apparatus, without necessitating actual printing out of the document under preparation. As a result, the printing time and paper for check-printing can be omitted to simplify the document preparation.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to channel coding and decoding in digital communications, particularly high-speed, broadband wireline communications. 2. State of the Art Channel coding refers to data transformations, performed after source encoding but prior to modulation, that transform source bits into channel bits. Trellis coding is one class of channel coding. Trellis encoders and decoders find widespread use in digital communications, an example of such use being xDSL modems such as HDSL2/G.SHDSL modems. One specific trellis decoder is the Viterbi decoder. Trellis encoders and Viterbi decoders are described, for example, in U.S. Pat. No. 5,457,705, incorporated herein by reference. A block diagram of a known data transmission system using a trellis encoder and a Viterbi decoder is shown in FIG. 1 and includes a transmitter comprising convolutional encoder 41 , mapping circuit 42 for setting an arrangement of signal points, and 8-PSK (phase shift keying) modulator 43 for phase-modulating which is supplied with 8 signal points generated by 2 3 bits, and a receiver comprising 8-PSK demodulator 44 and Viterbi decoder 45 . Convolutional encoder 41 produces output signal points Y 2 , Y 1 , Y 0 that are mapped into the position shown in FIG. 2 of the accompanying drawings by mapping circuit 42 and then modulated by 8-PSK modulator 43 for transmission to a transmission path. The 8-phase-modulated signal, with noise added during transmission, is demodulated into m-bit soft decision I channel, Q channel (I-ch., Q-ch.) data by 8-PSK demodulator 44 . The m-bit soft decision I-ch., Q-ch. data are supplied to Viterbi decoder 45 , which produces estimated information data d. Although different data transmission systems use different modulation coding arrangements, some of which may only be one-dimensional instead of two-dimensional (I, Q), the foregoing system may be regarded as exemplary for purposes of the present discussion. A block diagram of a typical trellis encoder, or convolutional encoder, is shown in FIG. 3, operation of which will be described. Convolutional encoder 41 is supplied with parallel information bits X 1 , X 2 that have been converted by serial/parallel converter 101 connected to input terminals 77 , 78 of convolutional encoder 41 . If the encoding ratio is 2/3, then exclusive-OR gates 85 , 86 of convolutional encoder 41 output exclusive-OR of information bits X 1 , X 2 supplied from input terminals 77 , 78 and output signals from shift registers 82 , 83 , and are stored in respective shift registers 83 , 84 . At this point, convolutional encoder 41 outputs, as encoded data, output signals Y 1 , Y 2 as respective information bits X 1 , X 2 and redundancy bit Y 0 from respective output terminals 80 , 79 , 81 . Each time information bits X 1 , X 2 are inputted, convolutional encoder 41 repeats the above operation and produces output data Y 1 , Y 2 , Y 0 . Output data Y 1 , Y 2 , Y 0 are then mapped into the positions shown in FIG. 2 by mapping circuit 42 of FIG. 1 . If there are three input information bits X 1 , X 2 , X 3 and the encoding ratio is 3/4, then, assuming that convolutional encoder 41 is used, convolutional encoder 41 adds redundancy bit Y 0 depending on information bits X 1 , X 2 to information bits X 1 , X 2 , X 3 , and produces 4-bit output data. Operation of Viterbi decoder 45 will be described below with reference to FIG. 4, FIG. 5, FIG. 6, and FIG. 7 of the accompanying drawings. FIG. 4 shows the trellis transition of convolutional encoder 41 . FIG. 5 shows an ACS (add compare select) circuit composed of adders 50 through 53 , comparator 54 , and selector 55 , and FIG. 6 also shows the ACS circuit. FIG. 7 shows Viterbi decoder 45 . In FIG. 7, the m-bit soft decision I ch., Q ch. data decoded from an 8-PSK signal are supplied from input terminals 87 , 88 , respectively, to branch metric generator 89 , which determines likelihood estimates (branch metrics) BM 0 , BM 1 , . . . , BM 7 between the 8-phase signal points and reception points as shown in FIG. 2 . The likelihood estimates BM 0 , BM 1 , . . . , BM 7 are supplied to ACS circuit 90 . To process a 0th state as shown in FIG. 5, branch and path metrics BM 0 ′, PM 0 , branch and path metrics BM 2 ′, PM 2 , branch and path metrics BM 4 ′, PM 4 , and branch and path metrics BM 6 ′, PM 6 are added by respective adders 50 , 51 , 52 , 53 , and a path metric with maximum likelihood is calculated by comparator 54 and selected by selector 55 as a path metric PM 0 on the next occasion. It is assumed that a path that has transited from a 4th state is selected. Upon selection of the path, the history data of the path stored in 4th-state shift register 75 (see FIG. 6) in path memory 91 is shifted to the right into 0th-state shift registers 73 by select signals SEL 0 applied to selectors 56 , 60 , 64 , 68 , so that 0th-state shift registers 73 store two information bits “01” that are a transition output. Similarly, the above operation is simultaneously carried out with respect to the 1st, 2nd, . . . , 7th states by circuits based on the trellis transition shown in FIG. 4 . Each time a received symbol is inputted, path metrics PM 0 -PM 7 with maximum likelihood are detected by maximum likelihood decider 92 , and the output signal from the final shift register which represents the state of the most likelihood path is selected by selector 72 , thus producing estimates X 2 , X 1 indicative of estimated decoded bits. In order to cover a wide variety of services XDSL standards, such as G.SHDSL, typically specify more than one data rate. Moreover, past experience dictates the need for higher and higher data rates. There are various ways to address this issue of high data rate system with multi-rate functionality. One straightforward approach is to increase the bandwidth of the transmitted signal in proportion to the required data rate. However, this is not a very efficient use of the bandwidth. Another approach is to change the number of bits per symbols, i.e., more bits per symbols for higher data rates. In this approach it is not necessary to increase the bandwidth. The difficulty of the variable bits per symbol is that if proper care is not taken, the associated trellis encoding/decoding arrangement can become unduly complex. What is needed is a careful design of the trellis encoding/decoding arrangement so that the multiple bits per symbol for various data rates can be used seamlessly. The present invention addresses this need. SUMMARY OF THE INVENTION The present invention, generally speaking, provides efficient trellis encoder/decoder structure that is suitable for accommodating multiple bits per transmitted symbol. On the encoder side for every rate we map the input bits to a transmitted symbol in such a way that the logic required for decoding the encoded bits is virtually the same irrespective of the number of bits per symbol. This results in greatly simplified decoder structure. BRIEF DESCRIPTION OF THE DRAWING The present invention may be further understood from the following description in conjunction with the appended drawing. In the drawing: FIG. 1 is a block diagram of a conventional data transmission system; FIG. 2 is a diagram illustrating signal points in the data transmission system of FIG. 1; FIG. 3 is a block diagram of a conventional trellis encoder; FIG. 4 is a diagram showing a conventional trellis transition with an encoding ratio of 2/3; FIG. 5 is a block diagram of a conventional ACS circuit; FIG. 6 is a block diagram illustrating a selection sequence of the ACS circuit of FIG. 5; FIG. 7 is a block diagram of a conventional Viterbi decoder; FIG. 8 is a block diagram of a conventional 16 PAM trellis encoder used in HDSL2 systems; FIG. 9 is a block diagram of the convolutional encoder of FIG. 8; FIG. 10 is a diagram illustrating a bits-to-symbol mapping of the convolutional encoder of FIG. 8; FIG. 11 is a state diagram of the convolutional encoder of FIG. 8; FIG. 12 is a diagram further elaborating the state diagram of FIG. 11; FIG. 13 is a block diagram of a multi-rate constellation mapper; FIG. 14 is a modified bits-to-symbol mapping for 16 PAM allowing for simplified decoding of multi-rate signals; FIG. 15 is a bits-to-symbol mapping for 8 PAM; FIG. 16 is a bits-to-symbol mapping for 4 PAM; FIG. 17 is a bits-to-symbol mapping for 2 PAM; FIG. 18 is a block diagram of a Viterbi decoder in accordance with an exemplary embodiment of the present invention; FIG. 19 is a partial trellis diagram corresponding to the state diagram of FIG. 11; FIG. 20 is a diagram illustrating cosets used by the Branch Metric Generator of FIG. 18; FIG. 21 is a diagram illustrating the effect of a truncation operation performed by the Branch Metric Generator of FIG. 18; FIG. 22 is a diagram illustrating operation of the ACS block of FIG. 18; FIG. 23 is a diagram illustrating a row switching operation performed by the Path Update block of FIG. 18; FIG. 24 is a diagram illustrating a traceback table update operation performed by the Path Update block of FIG. 18; FIG. 25 is a block diagram of the Decision block of FIG. 18; FIG. 26 is a diagram illustrating operation of the Decision block of FIG. 18; and FIG. 27 is a block diagram of a more generalized Decision block that may be used in conjunction with a transmitter having a higher than normal data rate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 8, a block diagram is shown of a conventional 16 PAM trellis encoder used in HDSL systems. A data binary signal (having a rate of 1.552 Mbps, for example) is input to a serial-to-parallel converter that produces parallel bits x 0 , x 1 and x 2 . Bits x 1 and x 2 are uncoded bits. Redesignated as y 2 and y 3 , respectively, they are applied directly to a PAM mapper. Bit x 0 is to be encoded and, therefore, applied to a convolutional encoder of the type shown in FIG. 9, for example, comprising a chain of flip-flops, selected output signals of which are exclusive-ORed in the manner indicated. In this manner, the convolutional encoder produces encoded bits y 0 and y 1 , which are applied to the PAM mapper. The PAM mapper performs a bit-to-symbol mapping and outputs a 1/3 rate signal, e.g., a 517K symbols per second for input rate of 1.552 Mbps. Referring to FIG. 10, the bits y 3 y 2 y 1 y 0 may be represented by a 12-bit value having a first 5-bit portion including a sign bit a four magnitude bits and a 7-bit zero-filled portion. The number of zero-filled bits determines the precision available for soft decision on the decoder and the overall performance of the trellis encoded modulation scheme. Referring now to FIG. 11, a state diagram is shown of the trellis encoder of FIG. 9 . Since the trellis encoder has nine flip-flops, it is described by 2 9 =512 states. The transition from one state to the next is governed by the next input bit to the trellis encoder. In FIG. 11, a possible transition is represented by a line from one state to another state labelled with the binary logic value (0 or 1) of the data bit causing the transition and, in parentheses, the logic values of the two output bits produced by the trellis encoder. For example, if the trellis encoder is in state 0 at time n and the next input bit is a 0, the trellis encoder will remain in state 0 at time n+1 and will produce an output of 00. If the trellis encoder is in state 0 at time n and the input next bit is a 1, the trellis encoder will transition to state 1 at time n+1 and will produce an output of 10. As illustrated in FIG. 12, states i and i+256 enter the same next state for the same input bit but different outputs are produced. For example, if the trellis encoder is in state 0+256=256 at time n and the next input bit is a 0, the trellis encoder will transition to state 0 at time n+1 but will produce an output of 10. A significant feature of the present system is the ability to use the same decoder structure with signals of different data rates. This ability is made possible in part by adopting a different bits-to-symbol mapping than that used in the prior art. Referring more particularly to FIG. 13, a multi-rate constellation mapper is shown. The constellation mapper has different modes, allowing for different numbers of uncoded bits to be represented in a transmit data symbol. FIG. 14 shows a bits-to-symbol mapping employed by the constellation mapper of FIG. 13 in a 16 PAM mode (two uncoded bits). The interval [−1, 1) is represented, including the values −15/16, −13/16, etc., the denominator being implied rather than explicitly indicated. Beginning at the left hand side of the interval, the values of the symbols y 3 y 2 y 1 y 0 progress from zero (0000, mapped to −15/16) to 15 (1110, mapped to −1). As may be seen with reference to FIG. 10, this portion of the mapping is the same as in the prior art. In the right half of the interval, however, this portion of the interval may be imagined as being divided again in half, with the values that would ordinarily appear in one quarter section of the interval being swapped with the values that would ordinarily appear in the other quarter section of the interval. Hence, instead of the symbols values progressing from left to right as 8, 9, 10, etc., they progress as 12, 13, 14, 15, 8, 9, 10, 11. The reason for this mapping will become more apparent from the following description of the decoder structure of the present system. Mappings for 8 PAM, 4 PAM and 2 PAM are shown in FIG. 15, FIG. 16, and FIG. 17, respectively. The mappings for 8 PAM and 2 PAM may be considered to be consistent with the prior art mapping of FIG. 10 . In the mapping for 4 PAM, however, as compared to what would be the expected mapping based on FIG. 10 (e.g., from left to right, 00xx, 01xx, 10xx, 11xx), the symbols are exchanged between the left and right halves of the interval, and then, within the left half of the interval, the symbols are exchanged again. Referring to FIG. 18, a block diagram is shown of a decoder in accordance with an exemplary embodiment. In this embodiment, the input signal to the decoder is a value y m (which may be represented in signed two's complement form) on the interval [−1, 1), represented in this instance using 12 bits. The output of the decoder is a maximum-likelihood symbol estimate, assuming guassian noise, composed of bit estimates {circumflex over (x)} 2 , {circumflex over (x)} 1 and {circumflex over (x)} 0 , produced by a decision block using a most-recent estimate of the original encoded bit and the most significant five bits of y m , delayed by 64 symbols period within a buffer. Hence, the trellis decoder has a history depth of 64 symbols. The major portion of the work of the decoder is performed by the Branch Metric Generator (BMG), Add-Compare-Select (ACS), and Path Update blocks. Prior to describing an advantageous implementation of these blocks in accordance with one embodiment of the invention, the trellis representing operation of the decoder will be described with reference to FIG. 19 . FIG. 19 represents a partial trellis derived from the state diagram of FIG. 11 . Each transition from one state to the next within the trellis corresponds to a new value of y m . Transitions indicated in solid lines are between states shown within the partial trellis diagram of FIG. 19 . Referring now to FIG. 20, operation of the Branch Metric Generator of FIG. 18 will be described. With two encoded bits, y 1 and y 0 (FIG. 9 ), four combinations of y 1 y 0 are possible, namely 00, 01, 10, 11. Depending on the uncoded bits y 3 y 2 , the combination y 1 y 0 =00 may correspond to any of four different symbol values, −15/16, −7/16, 1/16 or 9/16. At the decoder, the minimum distance of the received symbol from this set of points is designated as d 0 . (Note that the decimal value of the subscript is the same as the binary value of y 1 y 0 .) The distances d 1 , d 2 , and d 3 are similarly defined. Each set of points used to compute, respectively, d 0 , d 1 , d 2 , and d 3 , defines a “coset.” Instead of calculating the distance between the received symbol and all of the points of the constellation, significant efficiency is gained by, for purposes of calculating distances, obtaining a quantity x from y m by (in the case of 16 PAM) dropping the two most significant bits from y m as shown in FIG. 21 . The effect is to map all of the points in the constellation to a single interval [0, 1/2) The distance d 0 is then defined as dis(1/16, x), the distance d 1 as dis(3/16, x), etc. As a result, instead of 16 values, the Branch Metric Generator is required to generate for each received symbol only the four values, d 0 , d 1 , d 2 , and d 3 . Note in FIG. 21 that the transformation from y m to x causes symbol values originally within the interval [0, 1/2) to be flipped about the midpoint of the interval. The various symbols mappings of FIG. 14, FIG. 15, FIG. 16 and FIG. 17 account for this occurrence. The values d 0 , d 1 , d 2 , and d 3 is squared to achieve optimum performance. The transformation from y m to x varies slightly between modes as shown in Table 1: TABLE 1 4 PAM Mode For the 4 PAM mode, out of the 12-bit input received, the 10 MSBs are selected. Input 12-bits: y = y(0:11) = y(0) y(1) y(2) y(3) y(4) y(5) y(6) y(7) y(8) y(9) y(10) y(11) Selected 10 bits: x(0:9) = y(0:9) = y(0) y(1) y(2) y(3) y(4) y(5) y(6) y(7) y(8) y(9) 8 PAM Mode For the 8 PAM mode, out of the 12-bit input received, the middle 10 bits are selected. Input 12-bits: y = y(0:11) = y(0) y(1) y(2) y(3) y(4) y(5) y(6) y(7) y(8) y(9) y(10) y(11) Selected 10 bits: x(0:9) = y(1:10) = y(1) y(2) y(3) y(4) y(5) y(6) y(7) y(8) y(9) y(10) 16 PAM Mode For the 16 PAM mode, out of the 12-bit input received, the 10 LSBs are selected. Input 12-bits: y = y(0:11) = y(0) y(1) y(2) y(3) y(4) y(5) y(6) y(7) y(8) y(9) y(10) y(11) Selected 10 bits: x(0:9) = y(2:11) = y(2) y(2) y(3) y(4) y(5) y(6) y(7) y(8) y(9) y(10) y(11). The ACS block of FIG. 18 may be realized as shown diagrammatically in FIG. 22 . Storage is provided for two vectors (each of, e.g., dimension of 512). One, J(n−1), is used to stored prior path-weight sums, and the other, J(n), is used to stored new path-weight sums derived from the prior path-weight sums. Each element of the vector J(n) is derived, in accordance with the state diagram of FIG. 11, as the minimum of: 1) the sum of a first selected element of the vector J(n−1) and a selected one of the distances d 0 , d 1 , d 2 , and d 3 ; and 2) the sum of a second selected element of the vector J(n−1) and a selected one of the distances d 0 , d 1 , d 2 , and d 3 . In the case of J 0 (n), for example, one observes from the state diagram of FIG. 11 that state 0 may be arrived at from state 0 if the output y 1 y 0 =00 (to which d 0 corresponds) or from state 256 if the output y 1 y 0 =10 (to which d 2 corresponds). The most likely path of the two paths is the one with the minimum path weight. In general, J   ( n ) = min  { J i      || ⌋  ( n - 1 ) + d Å set  \    \  ε ÷ ≡ C ε  [ i ] J ⌊     | ! + |   ->  ( n - 1 ) + d Å set  \    \  ⋂ ÷ ≡ C ⋂  [ i ] } where └X┘ is the largest integer not exceeding X, the floor operation, and where the appropriate D set value (d 0 , d 1 , d 2 , or d 3 ) in any particular instance is determined by look-up table, for example. Application of the foregoing expression is demonstrated by the following examples: J Σ→∩ ( n )=min{ J ∩i∈ ( n −1)+ d ∩ , J ∞Σ ( n −1)+ d Σ } Since all decisions depend on the relative values, not absolute values, of J i (n)'s, to avoid saturation, the values of J i (n) may be adjusted by subtracting the following quantity: J min  ( n - 1 ) ≡ min i  J i  ( n - 1 ) The Path Update block of FIG. 18 principally comprises a traceback table for storage of the received data sequence history. In an exemplary embodiment, the traceback table requires 512 by 64 bits of storage. A path update operation, in accordance with an exemplary embodiment, consists of 1) a series of row-switching operations; 2) a decision step performed in cooperation with the ACS block; and 3) an update operation in which the oldest column of the traceback table is dropped to accommodate the addition of a new column. The new column to be added is calculated as a 512 vector of 0's and 1's, dec[i], in conjunction with the calculation of J(n) of the ACS block, as follows: dec[ i ]=0 if C ∈ [i]≦C ∩ [i] dec[ i ]=1 if C ∩ [i]≦C ∈ [i] Each bit dec[i] represents the most likely value of the encoded bit x 0 assuming the most likely trellis path (of history depth 64 in this example) ending in a particular state. Each row of the traceback table implicitly represents one such path. After the new column to be added has been calculated, row switching is performed as illustrated in FIG. 23 . As may be appreciated from the preceding discussion, the ith state of the trellis encoder is preceded by either the └i/2┘ th state or the └i/2┘+256 th state. Therefore, during traceback table update, the i th row of the traceback table is replaced by either the └i/2┘ th row or the └i/2┘+256 th row depending on whether dec[i] is 0 or 1, as shown in FIG. 23 . For i=10, for example, the 10 th row of the traceback table is replaced by the 5th row if dec[ 10 ]=0, else by the 261 st row if dec[ 10 ]=1. Following row switching, a decision bit, {circumflex over (x)} 0 , for the current cycle is produced by using the minimum value of the ACS vector J i (n) to index into the first column of the traceback table. That is, {circumflex over (x)} 0 is the min_J_loc th bit of the first column of the traceback table after row switching where min_j  _loc = arg     min i  J i  ( n ) After the decision bit has been produced, the traceback table is updated by dropping the first column and adding a new last column computed along with the vector J i (n) as previously described. Update of the traceback table is illustrated in FIG. 24 . The Decision block of FIG. 18 is shown in greater detail in FIG. 25 . The decision bit {circumflex over (x)} 0 is output directly. Although the uncoded bits {circumflex over (x)} 1 and {circumflex over (x)} 2 could be estimated directly from y m , greater accuracy may be obtained by passing the decision bit {circumflex over (x)} 0 through an identical trellis encoder as used at the transmit side to produce estimates of ŷ 0 and ŷ 1 . Decision logic uses these estimates together with y m to estimate the uncoded bits {circumflex over (x)} 1 and {circumflex over (x)} 2 . Operation of the decision logic of FIG. 25 is illustrated in FIG. 26 . Different levels are used by the decision logic depending on the estimates of ŷ 0 and ŷ 1 . The significance of using different levels may be appreciated with reference to FIG. 18 . Ignoring y 0 and y 1 , distinguishing between different combinations of y 2 and y 3 requires accurately resolving the signal to within ½ the symbol interval, e.g., ½ ({fraction (2/16)})={fraction (1/16)}. Identical combinations of y 0 and y 1 , however, occur at a much wider interval, e.g., 4 symbol intervals. By using decision levels equidistant from identical combinations of y 0 and y 1 , the required precision is only ½ ({fraction (8/16)})={fraction (4/16)}. Greater accuracy therefore results. The efficient structure of the present decoder lends itself to more dense constellations, allowing for the possibility of increasing the transmit data rate by increasing the number of uncoded bits. In the example of HDSL2/G.SHDSL, for example, the number of uncoded bits may be increased by 1, 2, etc., resulting in 32 PAM, 64 PAM, etc. A description of how such higher data rates may be achieved is set forth in Appendix A. A block diagram of a more generalized Decision block allowing for multi-rate capabilities is shown in FIG. 27 . The Decision block, which may be used with 4, 8, 16, 32 or 64 PAM signals, receives one additional input bit, y 5 , and produces up to two additional output bits, {circumflex over (x)} 3 and {circumflex over (x)} 4 . A mode signal causes the decision logic to operate in accordance with the desired mode. It will be appreciated by those of ordinary skill in the art that the invention can be embodied in other specific forms without departing from the spirit or essential character thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalents thereof are intended to be embraced therein. APPENDIX 1 Encoder and Mapper The encoder takes n uncoded input bits and generates n + 1 coded output bits. Out of the n input bits, x 1 , x 2 , . . . , x n , only the first bit, x 1 goes though a trellis encoder. The trellis encoder is a ½ rate encoder, i.e., it generates 2 output bits y 1 and y 2 for every input bit x 1 . The rest of the input bits, x 2 , x 3 , . . . , x n , is unchanged and passed to the output and labeled as follows: x 2 → y 3 x 3 → y 4 ⋮ ⋮ ⋮ x n → y n + 1 . The n + 1 bits output of the encoder is then mapped to a 2 (n+1) -PAM (Pulse Amplitude Modulation) constellation. For example, if n = 4, the 5 bit output of the encoder is mapped to a 32-PAM constellation. In this document we only consider the values of n equal to or larger than 4. i.e., 32-PAM or higher constellation. In our convention, the bit labeled y 1 is the LSB (Least significant Bit) and y n+1 is the MSB (Most Significant Bit). The (n + 1) output bits is mapped to 2 (n+1) -PAM as follows. Let M = 2 (n+1) , the M normalized constellation points are defined as follows the i-th point  (2i − M + 1)/M, i = 0, . . . , M − 1. For n = 4, we have M = 32, and the normalized 32 constellation points are (2i − 31)/32, i = 0, . . . , 31. Let p = ∑ i = 1 n + 1     2 i  y i , be the decimal representation of the (n + 1) bits, assuming that y 1 is the LSB. Then the (n + 1) bits y 1 , y 2 , . . . , y (n+1) is mapped to the p-th normalized constellation point, i.e., y 1 , y 2 , . . . , y (n+1) → (2p − M + 1)/M, p = 0, . . . , M − 1. For example, in the case of n = 4, [y n+1 . . . y 1 ] = 00101 is mapped to the point −21/32. All the normalized constellation points will be represented using B binary bits in 2's compliment form. The number of bits B is larger than (n + 1) and the extra bits B − n − 1 determines the precision available for soft decision on the decoder and the over all performance of the trellis coded modulation scheme. We suggest that for reasonable performance at least 8 extra bits be provided for soft decision, i.e., B ≧ n + 9. 2 The Decoder The major blocks of the decoder remains the same expect for: i) the bits selected the computation of the four distances d 0 , d 1 , d 2 , and d 4 and ii) the number of bits stored to decode the uncoded bits and the decoding table for those uncoded bits. The differences are described below. 2.1 Bit selection for distance calculation The input to the trellis decoder is B bit wide. Let P is the number of extra bits allocated for precision of the soft decisions, i.e., P = B − n − 1. We will assume that P > 8. Let the input B bit wide numbers are represented as z 1 z 2 z 3 . . . z B , where z 1 is the sign bit and z B is the LSB. Out of these B bits we select the P + 2 bits for the calculation of the distance. Let the selected bits are represented as x 1 x 2 . . . x P+2 , then z n → x 1 z n + 1 → x 2 ⋮ ⋮ ⋮ x n + P + 1 → x P + 2 . In other words, we drop the first n − 1 bits and select the rest for the distance calculation. The exact computation of the distances follows similar steps as in the 16-PAM case. 2.2 Decoding of the uncoded (n − 1) MSBs For decoding the n − 1 uncoded MSBs we store the first n + 2 bits. z 1 , z 2 , . . . , z (n+2) , of the input in a buffer. The length of the buffer is identical to the trace back depth of the decoder. the n − 1 uncoded MSBs are decoded using the stored n + 2 bits of the B bit wide decoder input along with the 2 bit encoder output. Assuming that the n + 2 bits are singed integer, let I is the decimal representation of that n + 2 bit. note that I can range from −M to M − 1, where M = 2 (n+1) . Using this definition, the decoding rules are summarized below. Let the 2 bit encoder output be represented by ŷ 1 ŷ 0 and K  = Δ  ⌊ I + 3 + M - y * 2 8 ⌋ where y  2 * ŷ 1 + ŷ 0 and └x┘ is the largest integer not exceeding x, for example └2.9┘ = 2. Note that K lies in the range 0 to 2 n−1 − 1. Thus K can be represented by n − 1 bits in unsigned mode. The decoded bits are the binary representation of the number K. This completes the decoding scheme.

The present invention, generally speaking, provides efficient multi-rate trellis encoder and decoder structures. The trellis encoder allows for a variable number of uncoded bits to be represented in a transmit symbol. The decoder maps received symbols to a smaller constellation by dropping selected symbol bits, whereby, for each of multiple cosets, points within that coset are mapped to a fewer number of points. Substantial simplification of the decoder structure is therefore achieved.

This is a continuation, of application Ser. No. 08/668,527, filed JUN. 21, 1996, now abandoned. TECHNICAL FIELD The present invention relates generally to the field of volatile liquid vapor recovery and, more particularly, to an apparatus and a method for improving the efficiency of a combined adsorption/absorption tower vapor recovery system. BACKGROUND OF THE INVENTION When handling volatile liquids such as hydrocarbons including gasoline and kerosene, air-volatile liquid vapor mixtures are readily produced. The venting of such air-vapor mixtures directly into the atmosphere results in significant pollution of the environment and a fire or explosion hazard. Accordingly, existing environmental regulations require the control of such emissions. As a consequence, a number of processes and apparatus have been developed and utilized to recover volatile liquids from air-volatile liquid vapor mixtures. Generally, the recovered volatile liquids are liquified and recombined with the volatile liquid from which they were vaporized thereby making the recovery process more economical. The initial vapor recovery systems utilized in the United States in the late 1920's and early 1930's incorporated a process combining compression and condensation. Such systems were originally only utilized on gasoline storage tanks. It wasn't until the 1950's that local air pollution regulations began to be adopted forcing the installation of vapor recovery systems at truck loading terminals. Shortly thereafter, the "clean air" legislation activity of the 1960's, which culminated in the Clean Air Act of 1968, further focused nationwide attention on the gasoline vapor recovery problem. As a result a lean oil/absorption system was developed. This system dominated the marketplace for a short time. Subsequently, in the late 1960's and early 1970's cryogenic refrigeration systems began gaining market acceptance (note, for example, U.S. Pat. No. 3,266,262 to Moragne). While reliable, cryogenic systems suffer from a number of shortcomings including high horsepower requirements. Further, such systems require relatively rigorous and expensive maintenance to function properly. Mechanical refrigeration systems also have practical limits with respect to the amount of cold that may be delivered, accordingly, the efficiency and capacity of such systems is limited. In contrast, liquid nitrogen cooling systems provide more cooling than is required and are prohibitively expensive to operate for this type of application. As a result of these shortcomings, alternative technology was sought and adsorption/absorption vapor recovery systems were more recently developed. Such a system is disclosed in a number of U.S. Patents including, for example, U.S. Pat. No. 4,276,058 to Dinsmore, the disclosure of which is fully incorporated herein by reference. Such systems utilize a bed of solid adsorbent selected, for example, from silica gel, certain forms of porous mineral such as alumina and magnesia, and most preferably activated charcoal. These adsorbents have an affinity for volatile hydrocarbon liquids. Thus, as the air-hydrocarbon vapor mixture is passed through the bed, a major portion of the hydrocarbons contained in the mixture are adsorbed on the bed. The resulting residue gas stream comprising substantially hydrocarbon-free air is well within regulated allowable emission levels and is exhausted into the environment. It should be appreciated that the bed of adsorbent used in these systems is only capable of adsorbing a certain amount of hydrocarbons before reaching capacity and becoming ineffective. Accordingly, the bed must be periodically regenerated to restore the carbon to a level where it will effectively adsorb hydrocarbons again. This regeneration of the adsorbent is a two step process. The first step requires a reduction in the total pressure by pulling a vacuum on the bed that removes the largest amount of hydrocarbons. The second step is the addition of a purge air stream that passes through the bed. The purge air polishes the bed so as to remove substantially all of the previously adsorbed hydrocarbons. These hydrocarbons are then pumped to an absorber tower wherein an absorber fluid such as lean oil or other nonvolatile liquid solvent is provided in a countercurrent flow relative to the hydrocarbon rich air-hydrocarbon mixture being pumped from the bed. The absorber fluid condenses and removes the vast majority of the hydrocarbons from that mixture and the residue gas stream from the absorber tower is recycled to a second bed of adsorbent while the first bed completes regeneration. In order to achieve the most effective and efficient recovery of hydrocarbon from the hydrocarbon rich air-hydrocarbon mixture, it is necessary to maintain a particular level of absorber fluid during absorber tower operation. In the past this has been accomplished using a level control valve and float assembly arrangement. While such an arrangement is effective for its intended purpose, it does suffer from a number of shortcomings. First, it should be appreciated that dirt and rust, elements commonly found in the operating environment of most vapor recovery systems, tend to foul the operation of the level control valve and float assembly. Further, in cold weather conditions moisture and condensation contacting the level control valve and float assembly may freeze effectively preventing these components from properly operating and maintaining the necessary level of absorber fluid in the absorber tower to provide efficient operation. Second, it should be appreciated that many state of the art float assemblies incorporate diaphragms made from a resilient material such as polytetrafluoroethylene. Unfortunately, this material stiffens in cold weather conditions thereby impairing proper function. Further, many hydrocarbon fuel additives in use today chemically attack the material from which the diaphragms are constructed thereby necessitating frequent maintenance intervals for replacement and repair (perhaps as often as quarterly in northern climates subject to greater temperature extremes). Many other state of the art float assemblies incorporate piston arrangements in place of diaphragms. It should be appreciated, however, that these piston arrangements must include sealing rings. The same hydrocarbon fuel additives noted above for chemically attacking diaphragms, chemically attack the materials from which these piston rings are constructed. Such chemical attack often leads to ring swelling and disconfiguration that impairs proper float assembly operation. Accordingly this type of construction also nessitates frequent maintenance intervals for replacement and repair. The resulting downtime substantially reduces loading terminal productivity. Further, repairs may be unexpectedly required thereby interrupting delivery schedules and creating other significant inconveniences. Third, it should be noted that the level control valve is a purely mechanical device and as such is subject to constant wear. In particular, most level control valves incorporate a needle valve that becomes worn over time. Eventually this wear leads to a leaking condition that necessitates repair and further down time. A need is, therefore, identified for a new and improved approach for controlling the level of absorber fluid in the absorber tower during vapor recovery system operation. SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide an improved apparatus for the recovery of volatile liquids from an air-volatile liquid vapor mixture overcoming the above-described limitations and disadvantages of the prior art. Another object of the present invention is to provide an apparatus for the recovery of volatile liquids from an air-volatile liquid vapor mixture wherein significant increases in overall productivity are provided by increasing maintenance intervals and thereby reducing downtime. Advantageously, this is accomplished without any substantial increases in the capital cost of the equipment, using a relatively simple and inexpensive arrangement that may even be readily retrofitted to vapor recovery systems in the field. Still another object of the present invention is to equip the absorber tower of a vapor recovery system with a variable speed drive return pump that maintains the desired level of absorber fluid in the absorber tower to maximize absorber tower efficiency. Advantageously this design arrangement eliminates the need for a level control valve and float assembly commonly employed in prior art vapor recovery systems. As a result, more reliable system performance is provided and overall loading terminal productivity is enhanced. Additional objects, advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims. To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, an improved absorber fluid system circuit is provided for a volatile liquid vapor recovery system including at least one adsorbent bed, a vacuum pump for regenerating the bed, a heat exchanger for cooling the vacuum pump, an absorber tower for condensing the volatile liquid vapor and an absorber fluid source. The absorber fluid return circuit includes an absorber fluid return pump having an inlet and an outlet. A first conduit connects the inlet of the return pump to a discharge outlet on the absorber tower. A second conduit connects the outlet of the return pump to the absorber fluid source or storage tank. The absorber fluid return circuit also includes a motor for driving the return pump at different speeds and, accordingly, different return flow rates. Additionally, a means is provided for controlling the operating speed of the motor in response to the level of absorber fluid contained in the absorber tower. This is done in order to maintain the necessary amount of absorber fluid in the absorber tower to provide efficient and effective operation thereof so as to optimize hydrocarbon recovery. Preferably, the control means comprises a controller such as a dedicated microprocessor, an absorber fluid level sensor and a variable speed AC drive for varying the electrical frequency of the current to the drive motor in response to the level of absorber fluid sensed or detected in the absorber tower. In accordance with still another aspect of the present invention, a volatile liquid vapor recovery system is provided. More specifically, the volatile liquid vapor recovery system includes at least one adsorbent bed, a vacuum pump for regenerating the bed, an absorber tower for condensing volatile liquid vapor, an absorber fluid source and the absorber fluid return circuit just described. Advantageously, this volatile liquid vapor recovery system provides more reliable and dependable performance over a longer service life. More specifically, the unique absorber fluid return circuit eliminates many component parts including the level control valve and float assembly are commonly employed on state of the art equipment in the field and that require periodic replacement. Accordingly, down time is reduced and productivity for a loading terminal equipped with the present invention may be substantially increased. Still other objects of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. BRIEF DESCRIPTION OF THE DRAWING The accompanying drawing incorporated in and forming a part of the specification, illustrates several aspects of the present invention and together with the description serves to explain the principles of the invention. In the drawing: FIG. 1 is a schematical diagram showing a volatile liquid recovery system incorporating the improved absorber fluid return circuit of the present invention; and FIG. 2 is a detailed block diagram schematic of the control system for the absorber fluid return circuit of the present invention. Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawing. DETAILED DESCRIPTION OF THE INVENTION Reference is now made to FIGS. 1 and 2 showing the absorber fluid return, circuit 10 of the present invention incorporated into a liquid vapor recovery system, generally designated by reference numeral 12. As will become apparent as the description hereof proceeds, the absorber fluid return circuit 10 functions to significantly enhance the profitability and productivity of the adsorption/absorption vapor recovery system 12 by significantly extending maintenance intervals, lowering maintenance costs and increasing operating efficiency. The vapor recovery system 12 is generally of the type disclosed and described in U.S. Pat. No. 4,066,423 to McGill et al. and U.S. Pat. No. 5,515,686 to Jordan, and entitled "Absorber Fluid Circuit for Vapor Recovery System" the disclosures of which are fully incorporated herein by reference. As shown the vapor recovery system 12 is particularly suited to the recovery of vaporized hydrocarbons of the type expelled from trucks, tank cars and other vessels 14 as they are loaded with hydrocarbons from a storage tank 16 through a feed line 18. More particularly, those vapors are collected as an air-hydrocarbon vapor mixture in a collection line 20, attached to the truck 14 and delivered past a vapor check valve 22 and pressure/vacuum vent 24 to a condensate knock-out tank 26. From there, the air-hydrocarbon vapor mixture passes along the lines 28, 29 and 30 past open valve 32 (valve 33 is closed) to the first reaction vessel 34 including a first bed of absorbent 36. The bed 36 adsorbs the volatile hydrocarbon vapors and clean air is exhausted past the valve 38 into the environment, valve 39 being closed. Simultaneously, the adsorbent bed 40 in the second reaction vessel 42 is being regenerated: that is, the capacity of the bed 42 to adsorb vapor is being renewed. To achieve this end, valves 44 and 45 are initially closed and the vacuum pump 46 is operated to pull a vacuum on the bed 40 in the second reaction vessel 42. Generally, as is known in the art, a liquid ring, two-stage vacuum pump having a capacity of 100-2000 cfm is utilized for this purpose. Such a pump may, for example, be obtained from Graham Vacuum Pump of Batavia, N.Y. (e.g. Model 2V7240). As the pump 46 draws the vacuum down in the reaction vessel 42 to 22-28 inches of mercury vacuum, a mixture of air and volatile liquid vapor is pulled from the bed 40. This mixture is directed by the pump 46 through conduits 48, 50, 52 into the sealing fluid separator 54 by operation of the valve 56 (open) and the valve 57 (closed). The sealing fluid separator 54 separates the pump sealing fluid, required for proper operation of the liquid ring, two-stage vacuum pump 46, from both the condensed volatile liquids that are recovered and the air-vapor mixture that is directed through conduit 58 to the absorber tower 60. The sealing fluid recovered from the separator 54 is recirculated by pump 74 through the lines 59 to the vacuum pump 46 by way of the heat exchanger 76 which receives cooling lean oil from the storage tank 16 via feed lines 68 and 72 by means of the pump 70. Following heat exchange, the lean oil is returned to the storage tank 16 via lines 78 and 66. In this way the operative temperature of the vacuum pump 46 is controlled to provide better operating efficiency. Toward the end of the regeneration cycle, (e.g. when a specific vacuum level is reached or for a specific time such as the last one to two minutes of an approximately 10-17 minute cycle), a small quantity of purge air is introduced into the reaction vessel 42 by opening valve 45. This purge air is drawn from the ambient atmosphere through line 62 and is passed through the bed 40 to polish the absorbent clean of the remaining hydrocarbons. During this process it should be appreciated that the purge air is only introduced into the bed 42 at a rate sufficient to substantially maintain a pressure of approximately 22-28 and more preferably 25-27 inches of mercury vacuum. The purge air and the last of the hydrocarbons is also directed by the pump 46 through the separator 54 and conduit 58 to the absorber tower 60. As is known in the art, the absorber tower 60 provides a countercurrent flow of absorber fluid such as lean oil by means of a dispersal sprayer (not shown). This lean oil is provided from the storage tank 16 via feed lines 68 and 72 by means of the supply pump 70. The absorber fluid serves to condense the volatile liquid vapors from the air-volatile liquid vapor mixture drawn from the reaction vessel 42 by the pump 46 as just described. The condensed hydrocarbons and absorber fluid are preferably collected from the bottom of the absorber tower 60 by operation of an absorber fluid return pump 64 driven by a motor 65 (see also FIG. 2) and then delivered via conduit 66 through a one-way flow control valve (not shown) to the storage tank 16. Preferably, the pump 64 is a ANSI pump such as manufactured by Ingersoll-Dresser, capable of pumping between 25-200 gallons per minute. The sizing of the pump 64 and motor 65 depends upon the head pressure in the gasoline storage tank 16 and the desired pump or flow rate. A more detailed description of the absorber fluid return circuit 10 including the pump 64 and motor 65 will be found below. The residue air that exits from the absorber tower 60 is largely free of volatile liquid vapor. It, however, is preferably recirculated or recycled for introduction into the first reaction vessel 34 via the conduits 77 and 30. In this way, any residual volatile liquid vapor may be captured in the bed 36 to complete the cleaning of the air prior to exhausting into the environment past valve 38. Of course, as is well known in the art it should be appreciated that the reaction vessels 34 and 42 are essentially identical and that the operation thereof may be reversed as required to provide for continuous processing. This means that when the bed 36 is saturated, the bed 36 may be regenerated in the manner described above with reference to the bed 42 while the bed 42 is simultaneously utilized to capture hydrocarbons in the manner described above with reference to the bed 36. This is accomplished by simply reversing the operation of the valve pairs 32 and 33, 56 and 57, 38 and 44, and 39 and 45, respectively to control the flow through the vapor recovery system 12. In accordance with an important aspect of the present invention, the absorber fluid return circuit 10 will now be reviewed in detail. As should be appreciated from viewing FIGS. 1 and 2, the absorber fluid return circuit 10 includes the return pump 64 with the drive motor 65, the first conduit 80 for connecting the inlet of the return pump to a discharge outlet of the absorber tower 60 and the second conduit 66 for connecting the outlet of the return pump to the absorber fluid source 16. Additionally, the absorber fluid return circuit 10 also includes a means 82 for controlling the operating speed of the motor 65 in response to the level of absorber fluid contained in the absorber tower 60. Advantageously, the absorber fluid return circuit 10 effectively functions to maintain a relatively constant level of absorber fluid in the absorber tower 60. That level is a predetermined and desired level necessary to cause the absorber tower 60 to function at peak operating efficiency for the recovery of hydrocarbon vapor. More specifically describing the invention, the controlling means 82 includes an absorber fluid level sensor 84, such as a Gems liquid level indicator and transmitter sold under the trademark SureSite as manufactured by IMD Industries, Inc. of Plainville, Conn. This device detects the level of absorber fluid in the absorber tower 60 by determining the position of the absorber tower meniscus in the sight glass (not shown) provided on the side of and external to the absorber tower. A controller 86 such as a dedicated microprocessor is responsive to the detected absorber level and operates through a means such as a variable speed AC drive 88 (such as manufactured by Telemecanique, a division of Square D, under the trademark ALTIVAR (Part No. ATV-16U72N4)) for varying the operating speed of the drive motor 65 by establishing the frequency of the electrical current provided from the electrical power source 90 (e.g. utility power line, electrical generator). In this way, the pumping capacity of the pump 64 is controlled. Thus, as the absorber fluid level detected in the absorber tower 60 rises, the frequency is increased to increase the speed of the motor 65 and, therefore, the pumping capacity of the pump 64. As the absorber fluid level detected in the absorber tower 60 falls, the current frequency is reduced to reduce the speed of the motor 65 thereby reducing the pumping capacity of the pump 64. Thus, the absorber fluid level may be maintained substantially constant at substantially all times at a level where maximum absorber tower operating efficiency is always insured. Further, consistent operation is always provided even in extreme temperature conditions. This is a particular advantage in northern climates where low temperatures often result in ice formation which adversely effects the consistent operation of state of the art float assemblies. In summary, numerous benefits results from employing the concepts of the present invention. Advantageously, by means of the unique absorber fluid return circuit 10 described above, it is possible for the first time to continuously operate the absorber tower 60 at maximum efficiency. This is true regardless of climatic conditions including even the rapid temperature changes and temperature extremes often experienced in the upper Great Plains states. Further, the present absorber fluid return circuit 10 effectively eliminates the troublesome level control valve and float assembly commonly employed in prior state-of-the-art designs thereby significantly reducing maintenance requirements and downtime for repairs. The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.

An absorber fluid return circuit is provided for a volatile liquid vapor recovery system. The vapor recovery system includes at least one adsorbent bed for capturing volatile liquid vapor, a vacuum pump for regenerating the adsorbent bed, an absorber tower for condensing volatile liquid vapor and an absorber fluid source. The absorber fluid return circuit includes an absorber fluid return pump having an inlet and outlet and a first conduit for directing absorber fluid from the absorber tower to the inlet of the return pump. A second conduit directs absorber fluid from the outlet of the return pump to the absorber fluid source. A variable speed motor drives the return pump. The variable speed motor is controlled by a controller operatively connected to a sensor for sensing the level of absorber fluid in the absorber tower, a variable speed AC drive for varying the speed of the drive motor.

BACKGROUND 1. Field of the Invention The present invention relates to effecting a reliable electrical contact in a semiconductor device between a metalized wiring trace and a silicon substrate. More particularly the present invention pertains to a diffusion barrier for preventing the migration of silicon from the semiconductor substrate into the metalized electrical contact. 2. Background Art Where a metalized wiring trace, such as a wiring trace of aluminum makes contact with the surface of a silicon substrate, silicon migration is common from the substrate into the metalized wiring trace under certain biasing conditions. This movement of silicon tends to displace aluminum at other parts of the associated semiconductor device. It also tends to erode the surface of the substrate, causing pitting at the contact site. Pitting of prolonged duration tends to produce deep fissures which can jeopardize the integrity of the PN junction at the edge of the conductivity well in which the electrical contact is being effected. This latter problem becomes particularly acute as the trend toward miniaturization and densification calls for shallower conductivity wells. Thus, in the fabrication of semiconductor devices, structures must be included which prevent the migration of material from the semiconductor substrate into metalized electrical contacts through the interface at which such contact is effected. One solution has been to make metalized contacts out of aluminum saturated with silicon. This inhibits migration at the contact interface, but requires the use of relatively exotic metalization materials. Alternatively, efforts have been undertaken to construct a barrier to silicon migration at the contact interface. In this approach, titanium nitride (TiN) has been found to offer promise. In layer form disposed between a silicon substrate and a metalized wiring contact, titanium nitride affords an acceptably low-resistance electrical coupling between the two materials on either side, while also functioning to retard the migration of silicon into the metalized layer. Typically, such diffusion barriers have either been deposited as titanium nitride directly on the surface of the substrate, or developed by annealing in an atmosphere of nitrogen a layer of titanium that has been previously deposited on the surface. The barrier layers of titanium nitride need to be uniformly of a minimal thickness, if the barrier function is to be successful. While breaks in the barrier layer are obvious structural failures, it is not sufficient to effect mere continuity of the layer in order to achieve a satisfactory barrier. Any portions of the barrier layer that are overly thin will ultimately fail to prevent silicon migration, and thus be the cause of pitting and other migration-related problems. The task of creating a diffusion barrier which at all locations exhibits at least the requisite minimum thickness has become increasingly difficult as the drive toward miniaturization and device densification continues in the field of semiconductor devices. Contacts between metalized wiring traces and the surfaces of a silicon substrate are in most instances effected by way of a contact well etched through an electrically insulating layer of silicon dioxide on the surface of the substrate. One consequence of miniaturization and device densification is that less space is available to be used for such contact wells. Thus, the trend is to make them smaller. Nevertheless, as the diameter of such contact wells decreases, the deposition of material into the well from which to form a diffusion barrier becomes increasingly difficult. This is due to the step coverage pattern observed to occur in deposition efforts at such wells. The material being deposited simply finds its way less readily into the contact well, rather than onto the top surface of the surrounding insulative layer. Even the deposited material that does enter the well has about as much likelihood of ending up on the walls of the contact well as on its floor. It is only on the floor, however, that the deposited material can truly be effective in producing a diffusion barrier. Typically, the step coverage pattern that results is characterized by a very then layer of the material at the bottom of the contact well even when a thick layer is produced on the top of the surrounding insulative layer. In the typical step coverage pattern, an overhang structure made of the deposited material develops on the top of the sides of the contact well near its opening. The overhang structure is created from material which otherwise should have been deposited on the floor of the contact well. The overhang also closes the opening to the contact well, in effect shadowing the well floor from the deposition of additional material. The problem of thin depositions on the floor of a contact well is particularly acute at the periphery of the floor near the corners between the floor and the walls. Poor thin floor layering and corner coverage begin to be dominating characteristics in contact wells having the combination of depths in the range of from about 1.00 to about 2.00 microns and widths in the range of from about 0.70 microns to about 1.00 microns. Under such circumstances, the thickness of the floor layer will be only approximately 30 percent to approximately 50 percent of the thickness of the layer on the top surfaces of the surrounding insulation layer. In addition, overhang structures on the sides of the well cause the floor layer to be even thinner at its periphery. The problem of the inadequate deposition of material into a contact well cannot be resolved by simply depositing thicker layers of that material over the entire substrate. The materials deposited in creating diffusion barriers, namely, pure titanium (Ti) and titanium nitride (TiN) are not particularly good electrical conductors. Thick accumulations of such materials on the surface of a substrate will require in turn that the metalized wiring traces be correspondingly thicker if standard specification requirements for low wiring trace conductivity are to be complied with. Concrete examples of these problems will be appreciated through a discussion of two known, but flawed, methods of creating diffusion barriers of titanium nitride. FIG. 1 illustrates a typical semiconductor silicon substrate 10, having formed at the surface 12 thereof a P-type conductivity well 14 having a lower boundary 16 comprising a PN junction with the balance of the material of substrate 10. Formed on surface 12 of substrate 10 is a relatively thick electrically nonconductive insulative layer 18, typically comprised of silicon dioxide (SiO 2 ). In order to effect electrical coupling with substrate 10, it is necessary to form a contact well through insulative layer 18 to surface 12. The commencement of this process is illustrated in FIG. 1 by the formation on insulative layer 18 of a patterned resist mask 20 having an opening 22 developed therein at a position corresponding to the desired location for an electrical contact with substrate 10. The structure in FIG. 1 is then subjected to a controlled, dry anisotropic etching, typically in a plasma of carbon tetrafluoride (CF 4 ). When etching through insulative layer 18 is completed, photo-resist mask 20 is removed, resulting in the structure illustrated in FIG. 2A. There a contact well 24 can be seen to have been formed through insulative layer 18 so as to have a floor 26 and walls 28. As the purpose of contact well 24 is to permit electrical contact to be made with surface 12 of substrate 10, floor 26 of contact well 24 defines a contact surface on substrate 10. Before the surface of the structure shown in FIG. 2A is metalized, however, it is necessary to produce on floor 26 of contact well 24 a barrier to the migration of silicon from substrate 10 into such a metalized wiring trace. A first known method for producing such a diffusion barrier is illustrated in the sequence of FIGS. 2A, 2B, 2C and 2D. A clearer understanding of the process and problems involved will be gained by reference also to the enlarged detail views appearing in FIGS. 3A, 3B, and 3C of the corners 30 at the outer periphery of floor 26 of contact well 24. The walls 28 of contact well 24 are etched to remove therefrom polymers deposited during the dry etch in carbon tetrafluoride. Then a first layer 32 of titanium is formed by sputtered deposition on floor 26 and walls 28 of contact well 24, as well as on the top surface 33 of insulative layer 18. This is accomplished by placing semiconductor substrate 10 in a semiconductor processing chamber at low pressure and biasing substrate 10 as a cathode relative to a target anode a of titanium. Argon introduced into the pressure chamber is ionized to produce a plasma. The plasma impacts the titanium target, freeing ions thereof into the rarified gas of the processing chamber. The ions of titanium are driven by the electrical bias established between substrate 10 and the titanium target toward substrate 10, accumulating on the surface thereof as first layer 32. At this point the step coverage phenomenon becomes relevant for the first time. In FIG. 2A the contact well 24 depicted is intended to be a contact well of relatively small dimension. Contact well 24 has a diameter in the range of from about 0.70 to about 1.00 microns and a relatively high aspect ratio of about 1 (1.00), which results in a depth of from about 1.00 to about 2.00 microns. As a result, the disposition of first layer 32 of titanium in contact well 24 is not uniform. Atoms of titanium moving towards floor 26 of contact well 24 are in many instances drawn onto walls 28 instead. This results in the depositions of titanium on floor 26 of contact well 24 assuming the form of a relatively thin portion 34 of first layer 32. Thin portion 34 is thickest at the center of floor 26, but tapers toward corner 30 of contact well 24. This thinning is partially a result of the diversion onto walls 28 of material otherwise destined to accumulate on floor 26 of contact well 24. The accumulation of titanium onto walls 28, however, also forms overhang portions 36. These tend to shadow corners 30 from subsequent deposition and to thereby increase the thinning of depositions on floor 26 at its periphery. The resultant coverage at corner 30 of contact well 24 by first layer 32 of titanium is relatively unsatisfactory, as shown with additional detail in FIG. 3A. Thereafter, the structure shown in FIG. 2B is annealed at a high thermal temperature in ambient nitrogen. In this manner, first layer 32 of titanium is progressively converted from its exposed surface into a strata 38 of titanium nitride (TiN). Titanium does not react during annealing with insulative layer 18. Thus, the portions of first layer 32 of titanium on the top surface of insulative layer 18 and on walls 28 of contact well 24 are able to be fully converted to titanium nitride. The titanium nitride layer produced exhibits a volume somewhat enlarged from that of the original titanium layer 32. Thus, strata 38 (FIG. 2C) of titanium nitride is thicker proportionately than original layer 32, both on the top surface 33 of insulative layer 18 and on walls 28 of contact well 24. While titanium nitride functions very desirably as a barrier to the diffusion of silicon from substrate 10 into the metalized contact that will eventually be placed in contact well 24, the thickest portions of strata 38 of titanium nitride are not formed in the areas in which electrical coupling is to be effected with substrate 10. These thicker portions include upper layer 40 on the top surface of insulative layer 18 and overhang portions 42 on walls 28 of contact well 24. Disadvantageously, overhang portion 42 tapers into an extremely thin structure at corner 30 of contact well 24. On the very floor 26 of contact well 24, the formation of titanium nitride is particularly unsatisfactory, resulting in a thin portion 44 of strata 38 of titanium nitride. The reason that the layer of titanium nitride in the floor 26 of contact well 24 is so minimal relates to the interaction between thin portion 34 of first layer 32 of titanium shown in FIG. 2B with the material of substrate 10 upon which thin portion 34 is originally disposed. During annealing, while the exposed surface of thin portion 34 is reacting with free nitrogen to form titanium nitride, the material of thin portion 34 adjacent to substrate 10 is induced by the heat of annealing to migrate across surface 12 thereof into the lattice of silicon substrate 10, forming a diffusion region 46 (FIG. 2C) of titanium silicide (TiSi 2 ). As this process occurs more rapidly than the conversion of titanium into titanium nitride at the surface of thin portion 34, most of the titanium in thin portion 34 is consumed in producing diffusion region 46. Only a small surface fraction of thin portion 34 of first layer 32 of titanium is available for conversion into the migration barrier material, titanium nitride, in thin portion 34 of strata 38. Thus, at floor 26 of contact well 24, a dual conversion process occurs relative to the titanium of first layer 32 thereupon. This process will be discussed with additional clarity in relation to FIG. 3A, which is a schematic, detailed view of corner 30 of contact well 24 illustrating the effects on the mass of thin portion 34 of first layer 32 of titanium from the formation of diffusion region 46 alone. It should be understood that at the same time as diffusion region 46 is being formed from the mass of thin portion 34 of first layer 32 the balance of thin portion 34 is being converted into titanium nitride. In order to enhance a clear understanding of the dual processes involved, reference is made to FIG. 3B. There the surface 48 of the original profile of thin portion 34 of first layer 32 of titanium is illustrated for comparison by a dashed boundary. The migration of titanium from what was thin portion 34 of first layer 32 into substrate 10 results in the formation of diffusion region 46 of titanium silicate. That process, however, causes expansion in the silicon involved, raising the former floor 26 of contact well 24 in a domed surface 50 elevated even in relation to the former top surface 48 of thin portion 34 of first layer 32. It can further be observed in FIG. 3B that most of the mass of former thin portion 34 has been consumed in this process, leaving therefrom only a surface layer 52 of titanium for reacting with ambient nitrogen in the annealing process to produce a barrier layer of titanium nitrite. Overhang portion 36 of first layer 32 of titanium is shown in FIG. 3B as substantially unchanged, as titanium does not migrate into insulative layer 18. Accordingly, the full mass of overhang portion 36 remains in place in order to participate in conversion during the annealing process into titanium nitride. Nevertheless, as has already been pointed out earlier, the portion of the diffusion barrier formed on walls 28 of contact well 24 contributes to the barrier function only at the very bottom of walls 28 at corner 30 of contact well 24. There, the amount of titanium remaining from the formation of diffusion region 46 is even less than the thickness of surface layer 52 toward the center of contact well 24. FIG. 3C illustrates the effect of the second portion of the process occurring during annealing in which titanium in surface layer 52 and in overhang portion 36 of first layer 32 of titanium are converted into titanium nitride. In the process, the volume of the corresponding material is enlarged. Accordingly, in FIG. 3C for comparative purposes, the outer surface 54 of overhang portion 36 and the upper surface 56 of surface layer 52, both of titanium, are indicated by dashed lines. In place of each, respectively, appear overhang portion 42 and thin portion 44 of strata 38 of titanium nitride. The resultant upward expansion of surface layer 52 while minimal and the lateral expansion of overhang portion 42 at corner 30 of contact well 24 serves to thicken the layer of titanium nitride in the immediate area in which electrical coupling with substrate 10 is actually effected. Nevertheless, because of the rapidity of the migration of titanium from thin portion 34 of first layer 32 relative to the conversion of titanium in thin portion 34 into titanium nitride, the effectiveness of the resultant diffusion barrier is not reliable. In an effort to increase the amount of titanium in surface layer 52 which is available for conversion into titanium nitride, the deposition of additional quantities of titanium on floor 26 of contact well 24 have been attempted. Two problems arise as a result first, the success of depositing titanium on floor 26 of contact well 24 is, however, reflected in extremely thick layers of titanium on the top surface 33 of insulative layer 18, which in turn calls for an increase in the thickness of the metalized layer deposited thereupon in forming a metalized lead 58 shown in FIGS. 2C and 3C in contact well 24 engaging strata 38 of titanium nitride. Second while a diffusion region of titanium silicide, such as diffusion region 46, is desirable, diffusion region 46 need only be relatively shallow in order to accomplish its purpose of enhancing the conductivity of the interface effected at the contact surface defined by floor 26 of contact well 24. When additional titanium is deposited on floor 26, although some of the increase will be converted into titanium nitride, additional quantities of the increase just migrate into substrate 10, causing a deepening of diffusion region 46 thereinto. Diffusion region 46 thus extends closely to boundary region 16 of conductivity well 14 which has been known to produce shorting through conductivity well 14 into the portion of substrate 10 below boundary 16. The method illustrated in FIGS. 2A through 2D and in FIGS. 3A through 3C thus has the dual drawback of producing an overly deep diffusion region of titanium silicide or in lieu thereof an overly thin barrier of titanium nitride on floor 26 of contact well 24 where the barrier to silicon migration is most essential. This problem is most critical in corners 30 of contact well 24, where the shadowing effect of overhang portion 36 of first layer 32 of titanium is most pronounced due to step coverage patterns of sputter deposition. Efforts to overcome one of these two flaws in the resultant electrical contact work against the other. Ameliorating one intensifies the other, and the method disclosed cannot ultimately be substantially improved. Accordingly, resort has been made in the art to a second known method for producing a diffusion barrier, which is illustrated and will be discussed in relation to the series of steps depicted in FIGS. 4A through 4E in combination with the detailed view of FIG. 5. The second method, instead of relying upon the annealing process to produce the requisite layer of titanium nitride, deposits that layer utilizing reactive sputter deposition in an atmosphere of nitrogen. This modification then frees the semiconductor manufacturer from the need to place excessive titanium in the contact well in order that some of the titanium escape migration into the substrate to form a titanium silicate diffusion region. Accordingly, the titanium layer deposited in the first instance in the prior art method already described can be reduced in thickness, both on the floor of the contact well and on the upper surfaces of the insulative layer thereabout. The latter consequence then permits the use of thinner metalized wiring traces than are possible under standard conductivity specifications utilizing the method already described. In FIG. 4A in the second method, a contact well 24 identical to that illustrated in FIG. 2A is formed through insulative layer 18 to surface 12 thereof. Contact well 24 has a floor 26 at surface 12 which defines the contact surface at which electrical coupling with substrate 10 is intended, walls 28, and corners 30. A first layer 32a of titanium is produced on top surface 33 of insulative layer 18, and floor 26 and walls 28 of contact well 24. In the second method, first layer 32a of titanium is not relied upon for the production of the ultimate barrier layer of titanium nitride. Accordingly, as can be appreciated by comparison, first layer 32a of titanium can be substantially thinner than first layer 32 of titanium shown in FIG. 2B. Nevertheless, because of the aspect ratio and the small diameter of contact well 24, first layer 32a of titanium is reduced on floor 26 of contact well 24 to a thin portion 34a, while on walls 28 of contact well 24 overhang portions 36a still tend to further shadow the development of coverage by titanium in corners 30 of contact well 24. Before annealing the structure shown in FIG. 4B in order to develop from thin portion 34a thereof a diffusion region of titanium silicate, a first layer 60 (FIG. 4C) of titanium nitride is deposited on first layer 32a of titanium. This is accomplished in the manner of the sputter deposition of titanium, except that the process is conducted in an atmosphere of nitrogen, rather than argon. In relation to layer 60, however, step deposition patterning is also apparent. Layer 60 of titanium nitride thus comprises a thin portion 62 at floor 26 of contact well 24 and overhang portions 64 on each wall 28 thereof. As layer 60 of titanium nitride is deposited over another layer, such as first layer 32a of titanium, which itself possesses an overhang portion, the ability to place material of layer 60 of titanium nitride at the bottom of contact well 24 and to insure the integrity of that layer at the corners 30 of contact well 24 is more difficult. Significantly, however, thin portion 62 of layer 60 of titanium nitride constitutes the totality of the structure by which migration of silicon across the contact surface is precluded. Thereafter as shown in FIG. 4D, the structure of 4C is subjected to an annealing heat treatment. This treatment does not alter the material of layer 60 of titanium nitride, but only permits titanium in thin portion 34a of first layer 32a of titanium to migrate into substrate 10 producing diffusion region 46a of titanium silicide. This process increases the volume of material below thin portion 62 of layer 60 of titanium nitride lifting floor 26 of contact well 24 into a domed surface 50a upon which thin portion 62 of layer 60 of titanium nitride is lifted and stretched slightly in its lateral dimension. Thereafter as shown in FIG. 4E, a metalized lead 58 is deposited filling contact well 24 and engaging layer 60 of titanium nitride. The diffusion barrier resulting includes layer 60 of titanium nitride in combination with a relatively shallow diffusion region 46a. As can be seen in additional detail in the enlarged view appearing in FIG. 5, diffusion region 46a of titanium silicide is advantageously shallower than diffusion region 46 shown in FIG. 3C. The shallower penetration into substrate 10 by diffusion region 46a reduces the likelihood of shorting across boundary 16 of conductivity well 14. Nevertheless, even in the deposition of the material of layer 60 of titanium nitride in the bottom of contact well 24, it is difficult to produce an adequately thick diffusion barrier at that location without resorting to excessive depositions of titanium nitride on the top surface 33 of insulative layers 18. Frequently the combined thickness of first layer 32a of titanium and layer 60 of titanium nitride at that location is at least as great as the single strata 38 of titanium nitride produced in the first prior art method and shown in FIGS. 2C and 2D. This accordingly places similar constraints on efforts to thicken the actual diffusion barrier produced as were encountered in that earlier described prior art method. The problems of breaches in that diffusion barrier continue in the second method to be most acute at corners 30 of contact well 24. The results is an unreliable diffusion barrier and continued problems of pitting which appear to be able to be overcome only by increasing the quantity of titanium and titanium nitride disposed on the top of the surrounding insulative layers. This in return is reflected in undesirably thick metalized wiring traces. BRIEF SUMMARY AND OBJECTS OF THE INVENTION Accordingly one object of the present invention is to reduce surface pitting and the associated risk of conductivity well shorting apparent when electrical coupling is effected with the surface of a semiconductor substrate. Another object of the present invention is to produce a reliable diffusion barrier for an electrical contact with a semiconductor substrate which more effectively prevents silicon migration, even in an environment of increasing miniaturization and component densification. Yet another object of the present invention is to produce a diffusion barrier as described above which possesses a shallow diffusion region and a thick barrier layer of titanium nitride free of debilitating thinning or discontinuities at the corners of the contact well in which the diffusion barrier is formed. It is yet another object of the present invention to produce an electrical contact with the surface of a semiconductor substrate which reliably precludes silicon migration into the metalized wiring trace effecting the contact and which by minimizing the amount of titanium and titanium nitride deposited in forming the requisite diffusion barrier, permits the metalized wiring trace to be optimally thin. It is yet another object of the present invention to produce a diffusion barrier as described which may be manufactured using known techniques and without substantial additional manufacturing steps. Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. To achieve the foregoing objects, and in accordance with the invention as embodied and broadly described herein a method is provided for forming a diffusion barrier between a metalized contact and the surface of a semiconductor substrate. In the inventive method, the surface of the substrate is accessed to define thereat a contact region. A first layer of titanium is sputter deposited on the contact region followed by a reactive sputter deposited base layer of titanium nitride. A third layer, a backing layer of titanium, is then sputter deposited on the base layer of titanium nitride, and the entire structure is heated in an atmosphere of nitrogen. As a result, the titanium from the first layer of titanium migrates into the surface of the substrate at the contact region to form a diffusion region of titanium silicide. The depth of the diffusion region can be kept within acceptable limits by controlling the thickness of the first layer of titanium. During the heating, however, the backing layer of titanium is annealed to form a backing layer of titanium nitride disposed on the base layer of titanium nitride. Together these two adjacent layers of titanium nitride comprise a composite strata disposed between the surface of the diffusion region and the metalized electrical contact through which electrical coupling is effected with the substrate. The composite strata of titanium nitride is advantageously and reliably capable of preventing migration of silicon from the substrate into the electrical contact during operation of the semiconductor device of which the contact is a part. The conversion of titanium in the backing layer to titanium nitride results in a volume expansion both in the portion of the backing layer on the floor of the contact well and on the walls thereof. At the corners of the contact well, this advantageously serves to thicken the diffusion barrier and close discontinuities therein. A method is provided for forming diffusion barrier at the interface between a metalized contact and the surface of a semiconductor substrate. A three-layer sandwich is formed over the contact region and then annealed in free nitrogen. The sandwich is made of a titanium nitride layer interposed between layers of titanium. During the anneal, material from the titanium layer adjacent to the substrate migrates thereinto to produce a highly conductive diffusion region of titanium silicate. Concurrently during the anneal the other layer of titanium, which is exposed to the nitrogen atmosphere, is converted into a backing layer of titanium nitride which enhances the barrier effect of the titanium nitride layer at the center of the sandwich structure. The conversion of titanium to titanium nitride causes a physical expansion in the layer involved. This serves to enhance the thickness of the barrier layer at all locations, but of particular significance at the corners of the contact well. A diffusion region of controlled depth and the deposition of minimal amounts of titanium remote from the contact site itself are advantageous results of the disclosed process. The invention disclosed herein also contemplates a diffusion barrier fabricated according to the inventive method, as well as an electrical contact incorporating such an inventive diffusion barrier. The intermediate semiconductor structure arrived at using the inventive method prior to the step of heating the substrate to produce titanium nitride or the diffusion region of titanium silicide is also considered to be within the scope of the disclosed invention. As will be illustrated in the discussion which follows, a diffusion barrier produced according to the invention reliably prevents silicon migration without as a consequence causing either deep penetration of the substrate surface by titanium silicate diffusion regions, or the excessive deposition of titanium and titanium nitride on the surface of the structure. Advantageously, all deposition steps required in the inventive method can be performed in the same semiconductor processing chamber without intermediate handling. BRIEF DESCRIPTION OF THE DRAWINGS In order that the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope, the invention will be described with additional specificity and detail through the use of the accompanying drawings in which: FIG. 1 is a cross sectional elevation view showing the manner in which a typical contact well is formed through an insulative layer to the surface of a semiconductor substrate; FIGS. 2A-2D are a sequence of cross sectional elevation views illustrating the steps in a first known method for producing a diffusion barrier associated with an electrical contact at the surface of a semiconductor substrate; FIG. 3A is an enlarged detailed view of a portion of the structure illustrated in FIG. 2B; FIG. 3B is an enlarged view of the structure shown in FIG. 3A illustrating the effect of one of the two concurrently occurring processes when the structure in FIG. 3A is subjected to heat treatment; FIG. 3C is an enlarged view of a portion of FIG. 2D; and FIGS. 4A-4E are a sequence of cross sectional elevation views illustrating a second known method for producing a diffusion barrier associated with an electrical contact with the surface of a semiconductor substrate; FIG. 5 is a detailed view of a portion of the structure illustrated in FIG. 4E; FIGS. 6A-6E are a sequence of cross sectional elevation views illustrating the steps for producing a diffusion barrier associated with an electrical contact at the surface of a semiconductor substrate using the teachings of the present invention; and FIG. 7 is a detailed view of a portion of the structure illustrated in FIG. 6E. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and apparatus of the present invention will be described in relation to the sequence of illustrations comprising FIGS. 6A through 6E. In FIG. 6A, a contact well 24 has been formed through insulative layer 18 to surface 12 of substrate 10. Contact well 24 has a floor 26 at surface 12 of substrate 10 and walls 28 which are normal to and meet floor 26 at corners 30. Floor 26 of contact well 24 defines a contact surface on substrate 10 through which electrical coupling is to be effected. The formation of contact well 24 is effected typically using an isotopic dry etch of upper surface 66 of insulative layer 18 through a patterned photo resist mask in a plasma of carbon tetrafluoride (CF 4 ). This is followed by a secondary etch to remove from walls 28 polymers typically produced thereupon during the dry etch. As shown in FIG. 6B, a first layer 68 of titanium (Ti) is then deposited on upper surface 66 of insulative layer 18 and in contact well 24 on walls 28 and floor 26 thereof. In this manner first layer 68 of titanium is deposited on the contact region through which electrical coupling with substrate 10 is intended. First layer 68 of titanium is formed using sputter deposition techniques. At a low pressure a target of titanium is positively biased relative to substrate 10. An atmosphere of argon is introduced and ionized in the electrical field to produce a plasma which impacts the titanium target. Due to the impacts on the target of the plasma, free ions of titanium are scattered therefrom and then driven by the electrical bias between the target and silicon substrate 10 towards the substrate which functions as a cathode. Under conditions of increased miniaturization and component densification, contact well 24 typically will have a depth in the range of from about 1.00 microns to about 2.00 microns, and a width in the range from about 0.70 microns to about 1.00 microns. Under such conditions, step coverage patterns in the deposition of first layer 68 of titanium are apparent and first layer 68 of titanium comprises an upper portion 70 disposed on upper surface 66 of insulative layer 18, and a thin portion 72 on floor 26 of contact well 24. For the dimensions of contact well 24 stated above, thin portion 72 can be expected to exhibit a thickness of from about 30 percent to about 50 percent of the thickness of upper portions 70. Thin portion 72 exhibits its maximum thickness at the center of floor 26 of contact well 24, thinning in a peripheral direction therefrom toward corners 30. The peripheral thinning of thin portion 72 is a consequence both of the step coverage phenomena and the shadowing effect of overhang portions 74 located against walls 28 of contact well 24 between upper portions 70 and thin portion 72. While overhang portion 74 intrudes into the opening to contact well 24 near top surface 66 of insulative layer 18, like thin portion 72 of first portion 68 of titanium, overhang portion 74 thins noticeably in the direction of corners 30 of contact well 24. Thereafter, as shown in FIG. 6C, a base layer 76 of titanium nitride is formed on first layer 68 of titanium. This result is effected by using reactive sputter deposition in which an atmosphere of nitrogen is introduced to surround a titanium target biased as an anode and semiconductor substrate 10 biased as a cathode. The nitrogen is ionized into a plasma which impacts the titanium target freeing ions therefrom. These interact with the ambient nitrogen and are driven by the electrical bias toward the cathode substrate 10. As with first layer 68 of titanium, a step coverage pattern of deposition is apparent. Accordingly, base layer 76 includes an upper portion 78 disposed on upper portion 70 of first layer 68 of titanium and a thin portion 80 disposed in the bottom of contact well 24 on thin portion 72 of first layer 68 of titanium. Thin portion 80 of base layer 76 of titanium nitride exhibits its greatest thickness at the center of contact well 24. From that maximum thickness, however, thin portion 80 reduces in thickness in the direction of corners 30 of contact well 24. Between upper portion 78 and thin portions 80 base layer 76 of titanium nitride includes an overhang portion 82 disposed on overhang portion 74 of first layer 68 of titanium. It is the purpose of thin portion 72 of first layer 68 of titanium to develop a diffusion region in surface 12 of substrate 10 at the contact surface. It is anticipated that in the process all of the titanium in thin portion 72 will be consumed. Accordingly, and in order to control the depth of the resultant diffusion region, first layer 68 of titanium can possess a lesser thickness than was possible in the first prior art method for producing its diffusion barrier illustrated in FIGS. 2A-2D. On the other hand, it is the purpose of thin portion 80 of base layer 76 of titanium nitride to function as a barrier to silicon migration from substrate 10 into the metalized contact that will eventually fill contact well 24. In this role, it is important that thin portion 80 of base layer 76 of titanium nitride be sufficiently thick throughout the full extent thereof. The problems in this regard are most acute at corners 30 of contact well 24. According to the method of the present invention, the effectiveness of thin portion 80 of base layer 76 of titanium nitride is enhanced by the deposition thereupon of another layer of titanium which is then annealed in an atmosphere of nitrogen to produce an additional backing layer of titanium nitride. As shown in FIG. 6D, a backing layer 84 of titanium is formed on base layer 76 of titanium nitride. Backing layer 84 is deposited using reactive sputter titanium in the same manner as the formation of first layer 68 of titanium. Again, step deposition patterning is apparent. Accordingly, backing layer 84 comprises upper portions 86 on upper portion 78 of base layer 76 of titanium nitride. Backing layer 84 includes upper portions 86 above insulative layers 18 on upper portion 78 of base layer 76 of titanium nitride. Also, at floor 26 of contact well 24 backing layer 84 assumes the form of a thin portion 88 having a thickness in the range of from about 30 percent to about 50 percent of the thickness of upper portion 86. The reduced thickness in backing layer 84 at the bottom of contact well 24 arises again due to the step coverage phenomena in combination with the small diameter of contact well 24 when restricted by the deposition of overhang portion 74 of first layer 68 of titanium and overhang portion 82 of base layer 76 of titanium nitride. Between upper portion 86 and thin portion 88, backing layer 84 includes overhang portions 90 disposed on overhang portion 82 of base layer 86 of titanium nitride. Again, the thickness of both thin portion 88 and overhang portion 90 of backing layer 84 thin visibly in the vicinity of corners 30 of contact well 24. Nevertheless, as will be disclosed subsequently, the combination of backing layer 84 of titanium and the base layer 76 of titanium nitride ultimately serves to produce a reliable barrier to the migration of silicon from substrate 10 into the metalized contact that will fill contact well 24. Advantageously, the deposition of first layer 68 of titanium, base layer 76 of titanium nitride, and backing layer 84 of titanium can all be performed in a single semiconductor processing chamber without removing the substrate. The resultant structure deposited comprises a layer of titanium nitride sandwiched between coextensive layers of titanium. Thus the structure illustrated in FIG. 6D comprises an intermediate semiconductor structure for subsequent annealing in nitrogen to produce a diffusion barrier for preventing migration of silicon from semiconductor substrate 10 across the interface between an electrical contact and the portion of the surface 12 of substrate 10 electrically coupled to the electrical contact. In the annealing step which will be described in relation to FIG. 6E, the structure illustrated in FIG. 6D is subjected to heat treatment in an atmosphere of nitrogen. This results in titanium from thin portion 72 of first layer 68 of titanium migrating into substrate 10 at the contact surface forming there a diffusion region 92 of titanium silicide. Inasmuch as thin portion 72 of first layer 68 of titanium is not relied upon in the method of the present invention for the creation of the barrier layer itself, a small quantity of titanium can be deposited in first layer 68 and the depth of diffusion region 92 carefully controlled. Simultaneously during the heating process, backing layer 85 of titanium which is exposed to the ambient nitrogen forms backing layer 94 of titanium nitride, thereby adding to the thickness and security against silicon migration afforded by base layer 76 of titanium nitride. Together backing layer 94 of titanium nitride and base layer 76 of titanium nitride function as a composite strata 96 of titanium nitride disposed between the surface of diffusion region 92 and the metalized electrical contact 98 formed to fill contact well 24. FIG. 7 illustrates in enlarged detail the relationship of the components of composite strata 96. In particular, depicted for comparative purposes in FIG. 7 in dashed lines is the original surface 100 of thin portion 88 of backing layer 84 of titanium and the original surface 102 of overhang portion 90 of backing layer 84 of titanium. When backing layer 84 is converted to titanium nitride in the annealing process, the volume of the new material expands relative to the original titanium layer. Accordingly the surfaces 104 of backing layer 94 of titanium nitride are displaced as illustrated in FIG. 7 relative, respectively, to the corresponding upper surface 100 and outer surface 102 of the corresponding components of backing layer 84 of titanium. The increase in thickness is particularly useful in sealing breaks and in thickening the barrier layer at corners 30 of contact well 24. The volume increased by being experienced at the two relatively orthogonal surfaces, upper surface 100 of thin portion 88 and outer surface 102 of overhang portion 90, tends to close any gap in the barrier layer which might occur at corner 30. Typically, it is at corner 30 where the thinnest deposition of material occurs in known methods, both on floor 26 and walls 28 of contact well 24. The combination of a layer of titanium nitride formed by reactive sputter deposition adjacent to and in contact with a layer of titanium nitride formed by annealing in an atmosphere of nitrogen produces a composite strata of titanium nitride which is capable of preventing migration of silicon from a substrate, such as substrate 10, into an electrical contact, such as electrical contact 98, during the operation of the semiconductor device of which the contact is a part. The use of a layer of reactive sputter deposited titanium nitride permits the underlying layer of titanium which is in contact with the substrate itself to be of such a thickness as to minimize the depth of the diffusion region created therebelow during the annealing process. When the backing layer of titanium is converted to titanium nitride during the annealing process, the effective thickness of the diffusion barrier created is enhanced both through the addition of a second layer of titanium nitride and at corners 30 at the contact opening by the expansion phenomena illustrated in FIG. 7. An electrical contact employing therewith a diffusion barrier produced according to the method of the present invention is highly reliable in its ability to reduce pitting of the associated semiconductor surface, while simultaneously controlling the depth of the associated diffusion region of titanium silicate. In the process, a minimum quantity of titanium is deposited on the substrate, thereby contributing to the ability to employ metalized wiring traces of a desirably minimum thickness. All three deposited layers in the three-layer intermediate semiconductor structure by which the inventive diffusion barrier is created are able to be formed in the same semiconductor processing chamber. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

A device is provided by forming a diffusion barrier at the interface between a metalized contact and the surface of a semiconductor substrate. A three-layer sandwich is formed over the contact region and then annealed in free nitrogen. The sandwich is made of a titanium nitride layer interposed between layers of titanium. During the anneal, material from the titanium layer adjacent to the substrate migrates thereinto to produce a highly conductive diffusion region of titanium silicide. Concurrently during the anneal the other layer of titanium, which is exposed to the nitrogen atmosphere, is converted into a backing layer of titanium nitride which enhances the barrier effect of the titanium nitride layer at the center of the sandwich structure. The conversion of titanium to titanium nitride causes a physical expansion in the layer involved. This serves to enhance the thickness of the barrier layer at all locations, but of particular significance at the corners of the contact well. A diffusion region of controlled depth and the deposition of minimal amounts of titanium remote from the contact side itself are advantageous results of the disclosed process.

BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to a magnetic field sensor, comprising a Wheatstone bridge with at least four layered magnetoresistive elements on a substrate, each element being composed of at least three layers, comprising successively a first ferromagnetic layer, a non-magnetic layer and a second ferromagnetic layer. 2. Description of the Related Art Magnetic field sensors are used, inter alia, in compasses, in medical instruments, for measurement of rotation, acceleration and position, and in magnetic recording systems. A magnetic field sensor of the kind set forth is known from the publication by J. M. Daughton and Y. J. Chen, "GMR Materials for low-field applications", IEEE Transactions on Magnetics, Vol. 29, page 7705, 1994. The magnetoresistive elements described in the cited publication have a so-called Giant Magnetic Resistance effect. In the described multilayer magnetoresistive elements the resistance is dependent on the angle between the magnetization directions of the ferromagnetic layers. The resistance of these materials is low when the two magnetization directions of the ferromagnetic layers are parallel and is high when they are antiparallel. This effect is Utilized to measure external magnetic fields. The resistance variation in the magnetoresistive elements described in the cited article is of the order of from 2 to 10 percent in the range from 0 to 100 Oe (=8 kA/m). It also appears from the cited article that for operation of the described Wheatstone bridge with maximum sensitivity it is necessary that two magnetoresistive elements in opposite branches have the same sensitivity and that two magnetoresistive elements in adjacent branches have the opposite sensitivity to the same magnetic field. The known magnetoresistive elements, however, all have the same, symmetrical characteristic in the absence of an external magnetic field. This means that for a field strength H=0, all elements have the same sensitivity to changes in an external magnetic field. For a suitable operation of the bridge, therefore, it is necessary to generate magnetic auxiliary fields at the area of the magnetoresistive elements. The directions of these magnetic auxiliary fields of two opposite elements are then the same and the directions of the magnetic auxiliary fields of two adjacent elements are opposed, so that an external field attenuates the total magnetic field for one pair of elements and intensifies the total magnetic field for another pair of elements. A pair of magnetoresistive elements in opposite branches of the bridge then exhibits a decrease of the resistance whereas the other pair of magnetoresistive elements exhibits an increase of the resistance. Consequently, it is always necessary to use magnetic auxiliary fields in known sensors comprising magnetoresistive elements based on the described Giant Magnetic Resistance effect. SUMMARY OF THE INVENTION It is, inter alia, an object of the invention to provide a magnetic field sensor in which the sensitivities desired for the position within the bridge are intrinsically laid down in the magnetoresistive elements, so that no external magnetic auxiliary fields are required for measurements in an operating range around H=0. A magnetic field sensor of the kind set forth in accordance with the invention is characterized in that each of the magnetoresistive elements comprises one or more strip-shaped portions which extend in mutually parallel directions, that the first ferromagnetic layer exhibits uni-axial anisotropy in one plane and the second ferromagnetic layer exhibits uni-axial or uni-directional anisotropy in one plane, the magnetization of the second ferromagnetic layer being determined by exchange interaction with an antiferromagnetic layer provided on the second ferromagnetic layer, and that magnetoresistive elements arranged in two adjacent branches of the bridge circuit have approximately opposite magnetization directions of the second ferromagnetic layers. As a result of this step, the sensitivity of the magnetoresistive elements is positive and negative, respectively, depending on the magnetization direction of the second ferromagnetic layer relative to a magnetic field to be measured, and external magnetic fields are no longer required to adjust a positive or negative sensitivity for measurements around the field strength H=0. The first ferromagnetic layer exhibits a uni-axial anisotropy in one plane due to the growth in a magnetic field. The interaction between the antiferromagnetic layer and the second ferromagnetic layer effectively results in uni-directional anisotropy of the second ferromagnetic layer. This effect is referred to as exchange biasing in the literature. Approximately opposite magnetization directions of the ferromagnetic layers are to be understood to mean magnetization directions which enclose an angle in a range of between 160°and 200° relative to one another. In the literature the Giant Magnetic Resistance effect of these materials is also referred to as spin-valve effect. A special embodiment of a magnetic field sensor in accordance with the invention is characterized in that, in the absence of an external magnetic field, in each magnetoresistive element the magnetization of the first ferromagnetic layer extends substantially perpendicularly to the magnetization of the second ferromagnetic layer. The non-prepublished European Patent Application No. 93202875.6 (which is not by this discussion admitted to be prior art) describes a step to manufacture sensors based on the spin-valve effect which have better properties as regards linearity and hysteresis than the known sensors based on the spin-valve effect. This step implies that in the absence of an external magnetic field the magnetization direction, i.e. the anisotropy of the first ferromagnetic layer, extends substantially perpendicularly to the direction of the effective anisotropy, i.e. the magnetization of the second ferromagnetic layer. The effective anisotropy is the result of the exchange bias field due to the antiferromagnetic layer and the crystalline anisotropy of the second ferromagnetic layer. It is to be noted that for a magnetoresistive element in which the antiferromagnetic layer is replaced by a ferromagnetic layer having a high coercivity, the effective anisotropy of the second ferromagnetic layer can also be laid down by exchange interaction. Thus, in the context of the present Patent Application an antiferromagnetic layer is also to be understood to mean a ferromagnetic layer having a high coercivity. The magnetization direction of the first ferromagnetic layer relative to the second ferromagnetic layer, and hence the resistance of the element, is determined by the presence and magnitude of a magnetic field to be measured. An embodiment of such a magnetic field sensor then has a substantially linear characteristic in the range around the field strength H=0 and a better signal-to-noise ratio in comparison with a known sensor based on the spin-valve effect with parallel magnetization directions of the ferromagnetic layers. A next embodiment of such a magnetic field sensor is characterized in that each strip-shaped portion comprises several single domain structures, which are placed adjacent to each other in a direction parallel to the longitudinal direction of the strip-shaped portion and connected to each other by a conductor. The effective permeability of a magnetoresistive sensor element, and thereby the sensitivity to an external magnetic field, will be determined by the combined effect of the intrinsic magnetic anisotropy of the material and the shape anisotropy. The intrinsic magnetic anisotropy may for certain alloys be very small, leading to a very high magnetic permeability, and thereby to a very high sensitivity in sensor applications. However, in a magnetoresistive structure with a large length to width ratio the resulting shape anisotropy diminishes the effective magnetic permeability, thereby diminishing the sensitivity of magnetic resistive sensors with such a shape. The effect of shape anisotropy is that it stabilizes the magnetisation along the long axis of the structure. In order to increase the sensitivity the long strips have been broken up into several single domain structures. No shape anisotropy is obtained for a circle-shaped structure. A next embodiment of such a magnetic field sensor is characterized in that the single domain structures of several adjacent strip-shaped portions form a hexagonal grid. The arrangement of the single domain structures of adjacent strip-shaped portions in hexagonal grid patterns diminishes the effect on the sensitivity by mutual interactions between the single domain structures. A next embodiment of a magnetic field sensor in accordance with the invention is characterized in that in the immediate vicinity of each strip-shaped portion of a magnetoresistive element there is provided a current conductor whose longitudinal direction extends parallel to the longitudinal direction of the strip-shaped portion of the magnetoresistive element, the magnetization direction of the second ferromagnetic layer of the associated magnetoresistive elements extending substantially perpendicularly to the longitudinal direction of the current conductors. This step alms to enable the magnetoresistive elements of the sensor to generate a magnetic auxiliary field by means of a current flowing through the conductors, which auxiliary field extends substantially perpendicular to the longitudinal direction of said portions. These auxiliary fields can be used to operate the magnetic field sensor in an optimum range of the characteristic. A further embodiment of a magnetic field sensor in accordance with the invention is characterized in that a trimmer resistor is connected in series with at least one magnetoresistive element. Addition of one or more resistors enables compensation for possible unbalance of the bridge as caused by deviations of the elements in the bridge relative to one another. This is of importance for measurements on small static magnetic fields. An instrument for measuring a magnetic field may be provided with a sensor in accordance with the invention. An embodiment of such an instrument is characterized in that it comprises a control unit which is arranged to conduct a current through each of the current conductors in order to generate a magnetic auxiliary field for adjustment of a working point in the characteristic for the measurement of an external field. As a result of this step, a sensor can be operated in a range which is optimum for a desired measurement. For example, the working point can be adjusted in a range exhibiting maximum sensitivity or in a substantially linear range. A further embodiment of such an instrument is characterized in that the instrument comprises a control unit which is arranged to conduct a current through each of the current conductors whereby the output voltage of the bridge is maintained at a constant value by feedback, and also comprises means for measuring the current flowing through the current conductors. As a result of this step a magnetic auxiliary field is generated which has a magnitude equal to that of an external field to be measured but an opposite direction, the value of a current flowing through the current conductors being a measure of the measured external magnetic field. This measurement results in a more linear behaviour which is insensitive to temperature fluctuations. A further embodiment of such an instrument is characterized in that it comprises a control unit which is arranged to conduct a current through each of the current conductors in order to generate a magnetic field for saturating the magnetoresistive elements. This step enables correction of the zero deviation of the bridge. This is of importance for the measurement of small smile magnetic fields. The saturation of the magnetoresistive elements can be achieved for positive as well as negative field directions, in dependence on the direction of the applied current. A method of manufacturing a magnetic field sensor in accordance with the invention is characterized in that the second ferromagnetic layer and the antiferromagnetic layer are exposed, at a temperature higher than the blocking temperature, to a magnetic field which is generated by an electric current flowing in the current conductors, after which the temperature of said layers is lowered to a value below the blocking temperature while the magnetic field is sustained. This step fixes the direction of the effective anisotropy of the second ferromagnetic layer during the production, and hence the sensitivity of each magnetoresistive element in the Wheatstone bridge. The blocking temperature is the temperature at which the exchange bias field of the second ferromagnetic layer is substantially zero. The blocking temperature of, for example, a suitable FeMn alloy is 140° C. Another suitable material is, for example, NiO. BRIEF DESCRIPTION OF THE DRAWING The above and other, more detailed aspects of the invention will be described in detail hereinafter, by way of example, with reference to the drawing. The drawing consists of the following Figures: FIG. 1 shows diagrammatically a Wheatstone bridge; FIG. 2 shows a pattern of conductors with four magnetoresistive elements which together constitute a Wheatstone bridge; FIGS. 3A and 3B shows diagrammatically the construction of a part of a layered magnetoresistive element suitable for use in a sensor in accordance with the invention; FIG. 4 shows a pattern of current conductors for generating auxiliary fields; FIG. 5 shows an example of a trimmer resistor; FIGS. 6A, 6C and 6E show a characteristic with a negative slope of a magnetoresistive element as can be used in accordance with the invention; FIGS. 6B, 6D and 6F show a characteristic of a magnetoresistive element with a positive slope as can be used in accordance with the invention; FIG. 7 shows a pattern of conductors with four magnetoresistive elements, in which the magnetoresistive elements comprise circular shaped portions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the equivalent diagram of the bridge, composed of magnetoresistive elements 10, 11, 12, 13 in accordance with the invention, and a current source 14 for a current I in connected to the terminals 17 and 18. The output voltage U o is present across the terminals 15 and 16. The bridge can be operated by voltage control or current control. In comparison with voltage control, the current control shown here offers the advantage that a decrease of the output voltage U o in the event of an increasing temperature, due to a decrease of the relative magnetoresistive effect, is partly compensated for by an increase of the absolute value of the magnetoresistive elements 10, 11, 12, 13 in the bridge and which is caused by a positive temperature coefficient of the resistance material. FIG. 2 shows the conductor pattern 25 which can be used in a sensor in accordance with the invention. The conductor pattern 25 is provided in an insulated fashion on a substrate, for example, underneath the conductor pattern 45 or, for example, above and underneath the conductor pattern 45, so that these patterns overlap. These layers can be deposited, for example, by thin-film technology. The dimensions of such a sensor are, for example, 1×2 mm 2 . The conductor pattern 25 constitutes a bridge circuit in which each magnetoresistive element 10, 11, 12, 13 comprises a meandering conductor pattern in which each time a portion 21 (shown as two strip-shaped portions) consists of a spin-valve magnetoresistive material, and another portion 22 is made of a conductor whose resistance is not dependent on the magnetic field. Also present are four terminals 15, 16, 17, 18. In order to achieve the bridge effect the four magnetoresistive elements 10, 11, 12, 13 of the bridge need not occupy the position shown in FIG. 2. Arrows 23 and 24 in each portion of the four magnetoresistive elements 10, 11, 12, 13 denote the magnetization direction of the second ferromagnetic layer 34. By choosing this direction as indicated, the resistance variation in response to a variation of an external magnetic field will be the same in the magnetoresistive elements in opposite branches of the bridge, for example, the same in the magnetoresistive element 10 as in the magnetoresistive element 13, and opposed in magnetoresistive elements in adjacent branches of the bridge, for example in the elements 10 and 11. FIG. 3A shows the construction of a part of a magnetoresistive element as can be used according to the invention. The composition of the material of a magnetoresistive element is described in the non-prepublished European Patent Application No. 93202875.6 and can be obtained, for example, by successively depositing on a high-resistance silicon substrate 20: a first Ta layer 31, a first NiFe layer 32, a Cu layer 33, a second NiFe layer 34, an FeMn layer 35 and a second Ta layer 36. The first Ta layer 31 stimulates defect-free growth with a strong crystallographic structure and the second Ta layer 36 serves for protection against oxidation. Furthermore, an arrow 37 in FIG. 3A denotes the direction of the anisotropy of the first NiFe layer 32 and an arrow 38 denotes the direction of the effective anisotropy of the second NiFe layer 34. An arrow 39 in FIG. 3B denotes the component of a magnetic field H to be measured which is directed parallel to the effective anisotropy of the second NiFe layer 34. In the magnetoresistive elements 10, 11, 12, 13 used in accordance with the invention the easy magnetization direction of the sensitive ferromagnetic material of the first layer 32 extends substantially perpendicularly to the effective anisotropy of the second ferromagnetic layer 34. In this application, in which the magnetoresistive elements 10, 11, 12, 13 are shaped as a narrow strip, the easy magnetization direction of the sensitive first NiFe layer 32 extends parallel to the longitudinal axis of the strip. The easy magnetization direction of the first NiFe layer 32 is determined by the shape anisotropy of the strip and by the magnetocrystalline anisotropy induced by means of a magnetic field applied during the growth of the NiFe layer 32. The non-prepublished European Patent Application No. 93202875.6 describes two methods suitable to obtain this substantially perpendicular configuration of the two NiFe layers 32 and 34 in spin-valve materials. It is also to be noted that for a magnetoresistive element in which the antiferromagnetic layer is replaced by a ferromagnetic layer having a high coercivity, the effective anisotropy of the second ferromagnetic layer can also be defined by exchange interaction. FIG. 4 shows a conductor pattern 45 used as a current conductor in a sensor in accordance with the invention. This conductor pattern 45 is provided on a substrate 20 in an insulated fashion, for example above the conductor pattern 25, in such a manner that the patterns overlap. The conductor pattern 45 is used to apply magnetic auxiliary fields to enable the sensor to operate in an optimum working range. The optimum working ranges will be described in detail hereinafter with reference to FIG. 6. Magnetic field sensors in accordance with the invention can be manufactured in various ways. A first way is, for example, to heat the sensor beyond the "blocking" temperature and to cool it subsequently in locally different magnetic fields generated by means of an accessory with permanent magnets or coils. The blocking temperature is the temperature at which the exchange bias field of the second ferromagnetic layer is substantially zero. The blocking temperature of, for example a suitable FeMn alloy is 140° C. A second method consists, for example, of the local heating of, for example, the magnetoresistive elements 10 and 13 on the substrate 20 to a temperature beyond the blocking temperature, followed by cooling in a uniform magnetic field to a temperature below the blocking temperature, and subsequently the heating of, for example, the magnetoresistive elements 11 and 12, followed by cooling in an external magnetic field of opposite direction. A third method is a version of the first method in which the current conductors 40, 41, 42, 43 on the substrate generate the locally different magnetic fields. According to this third method the substrate as a whole is heated beyond the blocking temperature, and during the subsequent cooling to a value below the blocking temperature locally different magnetic auxiliary fields are generated via the current conductors 40, 41, 42, 43 arranged above the magnetoresistive elements 10, 11, 12, 13. The latter method it is to be preferred because it does not require external tools. For the described third method of manufacture the current conductors 40, 41, 43, 43 are connected to a negative pole of a voltage source by way of the terminals 402, 403, 404, 405, respectively, and the terminals 400, 401, 406, 407 are connected to a positive pole of the voltage source, or vice versa. The current conductors 40, 41, 42, 43 may also be used, for example to compensate a small field offset between the characteristics 64 or 65 of the magnetoresistive elements 10, 11, 12, 13 in the bridge. This field offset may be due, inter alia, to small differences in magnetic coupling between the NiFe layers and can be compensated by positioning the magnetoresistive elements 10, 11, 12, 13 in the optimum range of the characteristic 64 or 65 by application of a magnetic auxiliary field by means of a current flowing through the current conductors 40, 41, 42, 43. Further to these examples, the current conductors 40, 41, 42, 43 can also be used, for example, for calibration purposes in the case of a persisting bridge unbalance, or an unbalance occurring due to, for example, temperature variations. The output voltage U o (see FIG. 1) can be corrected by subtracting from the output voltage U o the mean value of the output voltages for both extreme drives to a positive field and a negative field. These drives can be obtained, for example by applying a bias current to the current conductors 40, 41, 42, 43. In order to set the magnetoresistive layers to a magnetically suitably defined state again after such extreme driving, use can be made of an external coil whereby a longitudinal field is briefly generated parallel to the longitudinal direction of the magnetoresistive portions after such extreme driving. FIG. 5 shows an example of a trimmer resistor as can be used according to the invention. This resistor can be connected in the bridge, in series with one of the magnetoresistive elements 10, 11, 12 or 13, by arranging the terminals 57 and 58 of the pattern 50, for example on the terminals 26 and 27 of the substrate 20. This trimmer resistor can be used during manufacture to compensate an unbalance in the bridge as caused by deviations between the magnetoresistive elements. This is of importance for measurements of small static magnetic fields. After measurement of the deviation and calculation of the compensation value for the trimmer resistor, the value of this trimmer resistor is adjusted by opening one or more U-shaped connections 51, 52, 53, 54, 55 and 56 in the pattern 50 formed by the resistors 500, 501, 502, 503, 504 and 505 having the values 32Ra, 16Ra, 8Ra, 4Ra, 2Ra and Ra, respectively. The adjusted value of the trimmer resistor can thus vary between 0 and 63Ra, Ra being a resistance value to be laid down in the design. The connections 51, 52, 53, 54, 55 and 56 can be opened, for example, by means of a laser of adequate power. FIGS. 6A-6F show the characteristics 64 and 65 of the magnetoresistive elements as used according to the invention. The characteristic 64 concerns, for example, the magnetoresistive elements 10 and 13 and the characteristic 65 concerns, for example, the magnetoresistive elements 11 and 12. The characteristic 64 is a superposition of a spin-valve magnetoresistive characteristic 60, being linear in a first approximation, and a quadratic characteristic 62 caused by the anisotropic magnetoresistive effect. Similarly, the characteristic 65 is a superposition of a characteristic 61 and the characteristic 63. For each magnetoresistive element the anisotropic magnetoresistive effect equals a given value 67. The resistance becomes lower when the magnetization is set perpendicularly to the current direction in an external magnetic field. A description of the anisotropic magnetoresistive effect is given, for example in Technical Publication 268, Philips Electronic Components and Materials, 1988. The difference in resistance 66 is caused by the spin-valve effect. Various methods of operating the magnetic field sensor can be deduced from the characteristics 64, 65. A first method consists in that, for example each magnetoresistive element is operated in a range of the characteristic 64 or 65 without a magnetic auxiliary field, and a second method consists in that each magnetoresistive element is operated in a range in which the slope of the characteristic is maximum. According to the first method, for a balanced bridge the output voltage U o for a sufficiently small H is substantially linear and given by: U.sub.o (H)=I.sub.in sHR.sub.0, (1) in which s is the contribution by the spin-valve effect to the sensitivity of the magnetoresistive material; this can be expressed in a formula as ##EQU1## R being the resistance of a single magnetoresistive element and H the field strength to be measured. R 0 is the minimum saturation resistance of the magnetoresistive element. In that case the anisotropic magnetoresistive effect does not contribute to the signal because it is the same for each magnetoresistive element. A bias current can be applied to the current conductors 40, 41, 42, 43 in order to enhance the linearity even further by feedback, if necessary. To this end, the current conductors 40, 41, 42, 43 are connected to one another in such a manner that 400 is an input, 401 is an output, and the terminals 402 and 404, 406 and 407, 403 and 405 are connected to one another. According to the second method, under the influence of a bias field generated by a current through a superposed current conductor 40, 41, 42, 43, each magnetoresistive element enters, a range of the characteristic 64 or 65 in which the slope is steepest. Consequently, this current is opposed for the magnetoresistive elements 10 and 13. In order to apply feedback still, the same bias current must be added for each magnetoresistive element. The connection of the current conductors 40, 41, 42, 43 is such that the terminals 402 and 407, 403 and 406 are interconnected, respectively. The bias current for the magnetoresistive elements 10 and 13 then flows between the terminals 400 and 405, and the bias current for the magnetoresistive elements 11 and 12 flows between the terminals 401 and 404. This second method utilizes the anisotropic magnetoresistive effect and the sensitivity of the magnetic field sensor is approximately a factor of two higher. To increase the sensitivity of the sensor the conductor pattern 25 of the magnetoresistive elements, as shown in FIG. 2, can be replaced by a conductor pattern in which each strip-shaped portion comprises several single domain circle-shaped structures. FIG. 7 shows the conductor pattern 70 with the strip-shaped portions 71 comprising single domain circle-shaped structures 72. The conductor pattern 70 constitutes a bridge circuit in which each magnetoresistive element 10,11,12,13 comprises a portion 71, shown as two stripe-shaped portions, which consists of several circle-shaped structures 72. The circle-shaped structures 72 are interconnected by a conductor whose resistance is not dependent of the magnetic field. Furthermore, the meandering conductor pattern comprises the portions 73, which portions are also made of a conductor whose resistance is not dependent on the magnetic field. The diameter of the circle-shaped single domain structures has to be smaller than the average dimension of a single domain of a large uninterrupted layer of magnetoresistive material without anisotropy. Further the directions of the easy magnetisation axes of the single domain structures of the magnetoresistive elements can be pointed to the same direction if a magnetic field is present during the growth of the NiFe-layer 32 and/or by introducing a small shape anisotropy by the application of ellipse-shaped structures, whose long axes are pointed to the longitudinal direction of the strip-shaped portion 71 of the magnetoresistive element. In order to diminish the mutual interactions of the circle-shaped single-domain portions 71 of the magnetoresistive elements, the circular-shaped structures 72 or the ellipse-shaped structures are arranged in a hexagonal grid. By way of example, in FIG. 7 a hexagon 74 is drawn between six circular-shaped structures 72 on three adjacent strip-shaped portions 71.

A magnetic field sensor is composed of layered magnetoresistive elements which are arranged in a bridge on a substrate. The magnetoresistive elements comprise two ferromagnetic layers which exhibit an uni-axial anisotropy in one plane and are separated by a non-ferromagnetic layer. During the manufacture of the sensor the magnetization directions of these ferromagnetic layers are laid down so that two elements in two adjacent branches of the bridge exhibit an opposed sensitivity to external magnetic fields. Moreover, in each magnetoresistive element the magnetization of a ferromagnetic layer is adjusted substantially perpendicularly to the magnetization direction of the other ferromagnetic layer. As a result auxiliary fields are no longer required for the measurement of small magnetic fields and the sensor is substantially free of hysteresis and has an enhanced linearity.

RELATED APPLICATIONS The present invention was first described in a notarized Official Record of Invention on Apr. 23, 2007, that is on file at the offices of Montgomery Patent and Design, LLC, the entire disclosures of which are incorporated herein by reference. FIELD OF THE INVENTION The present invention relates generally to a snow plow for a motor vehicle and, more particularly, to said snow plow comprising a plurality of blades in a staggered arrangement, thereby allowing replacement of an individual blade should any damage occur and air to flow through said plurality of blades enabling air to cool a radiator of the motor vehicle more efficiently. BACKGROUND OF THE INVENTION Snow plows are typically used to remove accumulated snow from streets and parking lots. While the effort of moving snow from one (1) part of a paved surface to another seems at first relatively straightforward, there are multiple issues to consider when evaluating the snow plow itself. First, there are fuel factors to be considered when driving around with it on the truck and not plowing snow. Secondly, the weight of the plow places additional burden on the suspension of the truck causing premature failure. Finally, the position of the plow, when not in use, forms a perfect barrier for the radiator possibly causing overheating problems. Accordingly, there exists a need for a means by which snow plows can address the disadvantages and their associated costs as addressed above. The development of the apparatus herein described fulfills this need. There have been attempts in the past to invent refined snow plows. U.S. Pat. No. 6,112,438 issued to Weagley discloses a snow plow that appears to be foldably collapsible toward a center section. Unfortunately, this patent does not appear to disclose an upper, middle and lower blade that are positioned upon structural frame members in such a manner as to leave an opening for air to flow through the snow plow and decrease wind resistance on the plow. U.S. Pat. No. 6,044,579 issued to Hadler et al. discloses an articulated snowplow system that appears to comprise an angled snow plow that comprises rams on either side of the center to adjust the horizontal angle of the blades. Unfortunately, this patent does not appear to disclose three (3) snow plow blades that are mounted one (1) on top of the other in a horizontal manner so as to reduce wind resistance and wear on a vehicle's suspension. U.S. Pat. No. 6,035,560 issued to Pender discloses an air deflector with adjustable louver that is mounted on the upper surface of a snow plow. Unfortunately, this patent does not appear to disclose a louvered mechanism that is part of the snow plow, nor does it appear to disclose a series of three (3) blades that provide an opening for air passage to the radiator of a vehicle. U.S. Pat. No. 5,966,845 issued to DiGiacomo discloses an air stream deflector mountable thereto a snow plow. Unfortunately, this patent does not appear to disclose a louvered design snow plow that provides three (3) blades that permit the passage of air through the plow. U.S. Pat. No. 5,819,444 issued to Desmarais discloses a snow blade with tiltable lateral panels connected by hinges. Unfortunately, this patent does not appear to disclose three snow plow blades horizontally positioned upon one another which provide a gap for air to circulate through the plow to the radiator, consequently improving fuel economy and wear on the dedicated vehicle's suspension. U.S. Pat. No. D 396,236 issued to Eberle discloses a snow plow with a blade that is angled from the vertical center of the device. Unfortunately, this design patent does not appear to be similar in appearance to the disclosed apparatus, nor does it appear to comprise an upper, middle and lower blade that are attached to mounting members and permit airflow through the snow plow. U.S. Pat. No. D 377,653 issued to Matisz et al. discloses an angled snow plow blade structure. Unfortunately, this design patent does not appear to be similar in appearance to the disclosed apparatus, nor does it appear to possess three (3) blades that are connected by frame members that permit air flow through the plow structure. U.S. Pat. No. 5,544,434 issued top Calvachio discloses an air flow deflector that mounts on top of a snow plow. Unfortunately, this patent does not appear to disclose a louvered mechanism that is part of the snow plow, nor does it appear to disclose a series of three (3) blades that provide an opening for air passage to the radiator of a vehicle. U.S. Pat. No. D 310,225 issued to Matisz et al discloses an angled snow plow blade. Unfortunately, this design patent does not appear to be similar in appearance to the disclosed apparatus, nor does it appear to comprise an upper, middle and lower blade that are attached to mounting members and permit airflow through the snow plow. U.S. Pat. No. 4,896,915 issued to Morandi discloses a wind deflector plate for snow plow that appears to comprise a deflecting plate mounted on top of a plow which directs air when moving to the rear of the plow and the radiator of a motor vehicle. Unfortunately, this patent does not appear to disclose a louvered design snow plow that comprises three (3) horizontally mounted blades positioned in such a manner as to permit air circulation through the plow. U.S. Pat. No. 4,794,710 issued to Haring discloses a snowplow blade with spring-loaded edge flaps. Unfortunately, this patent does not appear to disclose a louvered design snow plow which permits air circulation through the plow. U.S. Pat. No. 4,587,750 issued to Larson discloses an air scoop mounted on snow plow. Unfortunately, this patent does not appear to disclose a louvered design snow plow that comprises three horizontally mounted blades positioned in such a manner as to permit air circulation through the plow. U.S. Pat. No. 2,085,996 issued to Phillips discloses a snow plow deflector that appears to comprise a circular deflector mounted on an upper surface of a snow plow to direct air to a radiator of a motor vehicle. Unfortunately, this patent does not appear to disclose three (3) snow plow blades horizontally positioned upon one (1) another which provide a gap for air to circulate through the plow to the radiator, consequently improving fuel economy and wear on the dedicated vehicle's suspension. None of the prior art particularly describes a snow plow for a motor vehicle comprising a plurality of blades in a staggered arrangement, thereby allowing replacement of an individual blade should any damage occur and air to flow through said plurality of blades enabling air to cool a radiator of the motor vehicle more efficiently that the instant apparatus possesses. Accordingly, there exists a need for snow plow that operates without the disadvantages as described above. SUMMARY OF THE INVENTION In light of the disadvantages as previously discussed in the prior art, it is apparent that there is a need for a louvered snow plow which reduces wind resistance and provides less stress on mechanical components of the attached vehicle. An object of the louvered snow plow is to provide a means for redirecting air into the engine compartment of a vehicle creating an additional cooling effect. A further object of the louvered snow plow is to reduce the weight of the plow and reduce the air resistance on the surface of the plow so that wear on attached vehicle is reduced. Another object of the louvered snow plow is to improve the fuel economy of a vehicle by the design of the plow. Still another object of the louvered snow plow comprises blades that are louvered and coordinate with one (1) another to form an overall concave surface, similar to that of a conventional plow blade. Still a further object of the louvered snow plow provides a coupling means to a vehicle such as pick-up truck, jeep, or similar vehicle, and could be adapted for use with larger utility trucks, or tractors. Yet another object of the louvered snow plow comprises a means to obliquely mount to the front end of the vehicle via an existing commercially available mounting frame. Yet a further object of the louvered design snow plow is to be retrofittable to an existing mounting frame and providing a simple means of attaching and detaching to a mounting frame. An aspect of the louvered design snow plow comprises a lower blade, a middle blade and an upper blade. Still another object of the louvered design snow plow provides the blades to be oriented in such a manner as to lower air resistance and increase airflow into the engine compartment. Still a further object of the louvered design snow plow provides the lower blade, and by extension the entire apparatus, with a side-to-side motion which is provided by the pivot mounting means to the mounting frame controlled by a user via the hydraulic cylinders. Another object of the louvered design snow plow comprises blades that are individually replaceable when worn or damaged, thereby eliminating the need to replace the entire blade as needed currently in conventional snow plows. Another aspect of the louvered design snow plow comprises a lower blade comprising a curved surface profile in which the face is perpendicularly oriented toward an amount of snow to be plowed and that is approximately one half (½) of the overall height of the apparatus. A further aspect of the louvered design snow plow comprises a middle blade located approximately one (1) inch above and behind the top horizontal surface of the lower scraper blade and comprises approximately one quarter (¼) of the overall height of the apparatus. The middle blade further comprises a shallow curved profile with a surface curvature less than that of the lower blade with the upper portion angled toward said lower blade approaching a horizontal orientation. Still another aspect of the louvered design snow plow comprises an upper blade located approximately one (1) inch above and behind the top surface of the middle blade and comprises approximately one quarter (¼) of the overall height of the apparatus. The upper blade further comprises a shallow curved profile with a surface curvature equivalent to that of the lower blade with the upper portion angled toward said lower blade approaching a horizontal orientation. Still a further aspect of the louvered design snow plow comprises a plurality of frame members that connect the blades to one another via a plurality of fasteners. The frame members comprise an overall curved profile and attaches to the back surface of the blades. A further aspect of the louvered design snow plow comprises an upper notch and a lower notch. The upper notch supports the upper blade and provides a spacing means with the middle blade and the middle notch supports said middle blade and provides a spacing means with the lower blade. The angle of the top surface of the notches is equivalent to the angle of the face of the corresponding blades. Yet another aspect of the louvered design snow plow comprises a scraper edge comprising an upper lip portion which attaches to the bottom front edge of the lower blade via a plurality of fasteners and that provides the snow scraping means for the apparatus. Still another aspect of the louvered design snow plow comprises a mounting bracket located in the lower center of the back surface of the lower blade and that is pivotally attached to the mounting frame by a mounting bracket pin through a mounting bracket aperture. Yet still another aspect of the louvered design snow plow comprises a hydraulic bracket located on either side of the mounting bracket and that is pivotally attached to the hydraulic cylinders of the mounting frame via a hydraulic bracket pin through a hydraulic bracket aperture. A further aspect of the louvered design snow plow comprises two (2) spring brackets located on the back surface of the lower blade and that provide an attachment means for the springs to the apparatus. The spring provides a resistance means when the apparatus strikes an unseen obstacle in the snow the entire apparatus will bend forward and pass over the obstacle. Another aspect of the louvered snow plow comprises a quadrant attached to the back surface of the lower blade that is removably attached to a common “C”-channel type segment or similar support of the mounting frame and that provides a means for supporting the apparatus in an upright position and pivoting said apparatus when plowing snow. An aspect of the louvered snow plow, in an alternate embodiment, comprises substantially similar materials and functions as the preferred louvered snow plow with the particular enhancement of the inclusion of the mounting frame as one (1) unit. Another aspect of the louvered design snow plow, in an alternate embodiment, comprises a lower lift frame comprising an “A”-frame member which attaches to the quadrant and the mounting bracket. The lower lift frame comprising two plow horns, two (2) stand hooks, and at least two (2) lock pin apertures. The stand hook engages a round member on the mounting bracket and provides added security and stability to the frame. A further aspect of the louvered design snow plow, in an alternate embodiment, comprises a hydraulic lift that attaches to the upper lift frame and provides the means of vertical lift to the louvered snow plow via a lift ram. The hydraulic lift drives the lift ram thus raising or lowering the lift arm. Still another aspect of the louvered design snow plow, in an alternate embodiment, comprises a mounting bracket that attaches to the front underside of a frame of the vehicle via a plurality of mounting fasteners. A receiving bracket is located subjacent to the mounting bracket and comprises a hollow channel which is suitable to receive the plow horn. Still a further aspect of the louvered design snow plow, in an alternate embodiment comprises a mounting frame further comprising two (2) angling rams which attach to the rear surface of the louvered snow plow at the hydraulic brackets. The angling ram is a hydraulic shock absorber or as a hydraulically actuated member which may be used to manipulate the plowing angle of the louvered snow plow. Yet a further aspect of the louvered design snow plow, in an alternate embodiment comprises a means of electrically controlling the up-down motion through the hydraulic lift and the side-to-side motion through the angling ram located within the cab portion of the vehicle. A method of installing and utilizing the apparatus may be achieved by performing the following steps: removing an existing snow plow blade from an existing mounting frame or installing a mounting frame to a vehicle; retrieving a louvered snow plow; attaching the apparatus to the existing mounting frame; pivotally attaching the mounting bracket to the mounting frame; inserting a mounting bracket pin through the mounting bracket aperture; removably attaching the distal end of the quadrant to an existing channel connection on the mounting frame; pivotally attaching each hydraulic bracket to a hydraulic cylinder of the mounting frame; inserting a hydraulic bracket pin through the hydraulic bracket aperture; removably attaching each spring to the mounting frame; positioning the apparatus as desired for use via the hydraulic cylinders on the mounting frame; plowing snow as normal; and benefiting from the utilization of the present apparatus. A method of installing and utilizing the alternate louvered snow plow may be achieved by performing steps substantially similar to those described for the preferred apparatus with the particular additions of the following steps: preparing the vehicle for the attachment of the mounting frame; attaching the mounting bracket to the front underside of the vehicle via the mounting fasteners; inserting the plow horns into the receiving bracket; engaging the stand hooks; inserting the lock pin through the aligned lock pin apertures; plowing snow as normal; and, benefiting from the utilization of the present alternate louvered snow plow. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: FIG. 1 is a front environmental view of a louvered snow plow 10 , according to a preferred embodiment of the present invention; FIG. 2 is a front perspective view of a louvered snow plow 10 , according to a preferred embodiment of the present invention; FIG. 3 is an exploded front perspective view of a louvered snow plow 10 , according to a preferred embodiment of the present invention; FIG. 4 is a rear perspective view of a lower blade 20 , according to a preferred embodiment of the present invention; FIG. 5 is a side profile view of a louvered snow plow 10 , according to a preferred embodiment of the present invention; and FIG. 6 is a side view of an alternate louvered snow plow 15 , according to a preferred embodiment of the present invention. DESCRIPTIVE KEY 10 louvered snow plow 15 alternate louvered snow plow 20 lower blade 22 middle blade 24 upper blade 30 frame member 32 upper notch 34 middle notch 40 scraper edge 50 fastener 52 fastener aperture 61 mounting bracket 62 mounting bracket aperture 63 hydraulic bracket 64 hydraulic bracket aperture 65 hydraulic bracket pin 66 spring bracket 67 eyelet 68 spring 69 mounting bracket pin 70 quadrant 100 vehicle 110 mounting frame 111 lower lift frame 112 upper lift frame 113 plow horn 114 stand hook 115 “A”-frame 117 angling ram 118 hydraulic unit 119 lift ram 120 lift arm 125 receiving bracket 126 frame mount 127 mounting fastener 128 lock pin aperture 129 lock pin 130 pin 131 frame fastener DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within FIGS. 1 through 4 . However, the invention is not limited to the described embodiment and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention, and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. The present invention describes a device and method for a louvered snow plow (herein described as the “apparatus”) 10 , which provides a means for a snow plow generally comprising a lower blade 20 , a middle blade 22 , and an upper blade 24 blade in lieu of one solid curved blade. The blades 20 , 22 , 24 are louvered and coordinate with one another to form an overall concave surface, similar to that of a conventional plow blade. This multi-blade louvered orientation is envisioned to provide a means for redirecting air thereinto the engine compartment of a vehicle 100 thereby creating an additional cooling effect, creating an aerodynamic lift similar to that seen in an airfoil thereby effectively reducing the weight of the apparatus 10 , and reducing the air resistance thereon the surface of said apparatus 10 thereby reducing the wear on the suspension and increasing the fuel economy of a vehicle 100 . Referring now to FIGS. 1 and 2 , front views of the apparatus 10 , according to the preferred embodiment of the present invention, is disclosed. The apparatus 10 is envisioned as being coupled thereto a vehicle 100 such as pick-up truck, jeep, or similar vehicle 100 , but it is not limited for use with light weight vehicles 100 and it is understood that said apparatus could be adapted for use with larger utility trucks, tractors, or the like. The apparatus 10 is obliquely mounted thereto the front end of the vehicle 100 via an existing commercially available mounting frame 110 . The mounting frame 110 provides the means of attaching the apparatus 10 thereto a vehicle 100 and controlling the vertical and side-to-side position of said apparatus 10 and is envisioned to comprise expected features such as, a hydraulic lift, hydraulic cylinders, hydraulic fluid hoses, mounting brackets, support and restraining members, lighting fixtures, and the like. Although illustrated here as retrofittable to an existing mounting frame 110 it is understood that the apparatus 10 may be introduced with a companion vehicle mounting frame 110 similar to other commercially available mounting frames 110 and as such should not be interpreted as a limit of said present apparatus 10 . The apparatus 10 is envisioned as being moved and oriented therein a vertical and a horizontal position through the use of a hydraulic system (not shown) integrated therein the mounting frame 110 . The apparatus 10 is envisioned as an improved retrofit thereto an existing snowplow and provides a simple means of attaching thereto and detaching therefrom the mounting frame 110 . Although it is understood that the apparatus 10 may be introduced comprising an accompanying plow frame 110 and hydraulic system as one (1) integrated unit. The blades 20 , 22 , 24 are envisioned as being between three thirty-seconds ( 3/32) and one fourth (¼) inch thick and preferably made of a painted or powdercoated steel, a durable plastic, or the like and fabricated through common metal or plastic processing techniques; each providing equal benefit to a user of the apparatus 10 . The lower blade 20 comprises a curved surface profile in which the face is perpendicularly oriented toward an amount of snow to be plowed and is approximately one half (½) of the overall height of the apparatus 10 . The middle blade 22 is located approximately one (1) inch above and behind the top horizontal surface of the lower scraper blade 20 and comprises approximately one quarter (¼) of the overall height of the apparatus 10 . The middle blade 22 further comprises a shallow curved profile with a surface curvature less than that of the lower blade 20 with the upper portion angled toward said lower blade 20 approaching a horizontal orientation. The upper blade 24 is located approximately one (1) inch above and behind the top surface of the middle blade 22 and comprises approximately one quarter (¼) of the overall height of the apparatus 10 . The upper blade 24 further comprises a shallow curved profile with a surface curvature equivalent to that of the lower blade 20 with the upper portion angled toward said lower blade 20 approaching a horizontal orientation. The orientation of the blades 20 , 22 , 24 provide for a lowered air resistance and increased airflow into the engine compartment. The blades 20 , 22 , 24 are connected to one another via a plurality of frame members 30 . The blades 20 , 22 , 24 attach thereto the frame members 30 via a plurality of fasteners 50 which are preferably common bolts and nuts, screws, or the like. Although the apparatus 10 is illustrated with the component parts attached by fasteners 50 it is understood that the blades 20 , 22 , 24 may be attached thereto the frame members by other attachment means such as welding or the like. The apparatus 10 further comprises a scraper edge 40 preferably made of steel or resilient rubber approximately three-eighths (⅜) to one half (½) inch thick. The scraper edge 40 comprises an upper lip portion which attaches to the bottom front edge of the lower blade 20 via a plurality of fasteners 50 and is envisioned to provide the snow scraping means for the apparatus 10 . Referring now to FIG. 3 , an exploded front view of the apparatus 10 , according to the preferred embodiment of the present invention, is disclosed. The apparatus 10 is depicted illustrating the manner in which the blades 20 , 22 , 24 are oriented thereon the frame members 30 . The frame members 30 comprise an overall curved profile which provides the curvature of the snow plow 10 and further comprises segmented curved profiles which provide the angle of the individual blades 20 , 22 , 24 . Each frame member 30 attaches to the back surface of the blades 20 , 22 , 24 and comprise an upper notch 32 and a middle notch 34 which provide a support and spacing means thereto said louvered blades 20 , 22 , 24 . The frame member 30 comprises a plurality of fastener apertures 52 located vertically along a center axis of said frame member 30 . Each blade 20 , 22 , 24 comprises a plurality of fastener apertures 52 which coincide with corresponding fastener apertures 52 therein the frame members 30 thereby accommodating a fastener 50 therethrough and enabling said blades 20 , 22 , 24 to attach thereto said frame members 30 . The scraper edge 40 comprises a plurality of fastener apertures 52 located on the upper lip portion of said scraper edge 40 and provide the attachment meant thereto the lower blade 20 via the fasteners 50 . Referring now to FIG. 4 , a rear perspective view of the lower blade 20 , according to a preferred embodiment of the present invention, is disclosed. The apparatus 10 comprises a mounting bracket 61 , two (2) hydraulic brackets 63 , two (2) spring brackets 66 and a quadrant 70 which provide the means for the apparatus 10 to attach thereto the mounting frame 110 . The mounting bracket 61 is located in the lower center of the back surface of the lower blade 20 and is pivotally attached thereto the mounting frame 110 via a mounting bracket pin 69 therethrough a mounting bracket aperture 62 . A hydraulic bracket 63 is located on either side of the mounting bracket 61 and is pivotally attached thereto the hydraulic cylinders of the mounting frame 110 via a hydraulic bracket pin 65 therethrough a hydraulic bracket aperture 64 . The lower blade 20 and by extension the entire apparatus 10 is envisioned to have a side-to-side motion which is provided by the pivot mounting means thereto the mounting frame 110 and is controlled by a user via the hydraulic cylinders. Two (2) spring brackets 66 are located toward distal ends of the back surface of the lower blade 20 and provide an attachment means for the springs 68 thereto the apparatus 10 . The spring 68 is attached thereto the spring bracket 66 on one (1) end via an eyelet 67 secured therein said bracket 66 and is attached thereto the mounting frame 110 on the other end. The spring 68 provides a resistance means when the apparatus 10 strikes an unseen obstacle in the snow the entire apparatus 10 will bend forward and pass over the obstacle. The apparatus 10 may also be introduced with differing resistance means such as but not limited to securing hooks which removably attach thereto an underside surface of the “A”-frame or the like. Although illustrated having two (2) springs 68 it is understood the apparatus 10 may be introduced comprising any plurality of springs 68 depending on the model of the apparatus 10 and as such should not be viewed as a limiting factor of the invention 10 . The quadrant 70 is attached thereto the back surface of the lower blade 20 via welding or through fasteners and removably attaches thereto a common “C”-channel type segment or similar support of the mounting frame 110 and provides a means for supporting the apparatus 10 in an upright position and pivoting said apparatus 10 when plowing snow. It is understood that the “A”-frame may be introduced in various dimensions depending on the mounting frame 110 to which attached thereto. Referring now to FIG. 5 , a side profile view of the apparatus 10 , according to a preferred embodiment of the present invention, is disclosed. The blades 20 , 22 , 24 are envisioned as being individually replaceable when worn or damaged, thereby eliminating the need to replace the entire blade as needed currently in conventional snow plows. The upper notch 32 supports the upper blade 24 and provides a spacing means therewith the middle blade 22 and the middle notch 34 supports said middle blade 22 and provides a spacing means therewith the lower blade 20 . The angle of the top surface of the notches 32 , 34 is equivalent to the angle of the face of the corresponding blades 22 , 24 . The lower blade 20 is envisioned as having a generally vertical orientation where an upper edge is in vertical alignment therewith a lower edge of said lower blade 20 . Referring now to FIG. 6 , a side view of an alternate louvered snow plow 15 , according to an alternate embodiment of the present invention, is disclosed. The alternate louvered snow plow 15 comprises substantially similar materials and functions as the preferred louvered snow plow 10 with the particular enhancement of the inclusion of the mounting frame 110 as one (1) unit. The mounting frame 110 attaches thereto the louvered snow plow 10 in an expected manner and generally comprises expected features similar to other similar commercially available vehicle mounted frames such as, but not limited to, a lower lift frame 111 , an upper lift frame 112 , a hydraulic lift 118 , and “A”-frame support member 115 , a vehicle mounting bracket 126 , and the like. The mounting bracket is preferably made of a durable material such as metal and be manufactured and attached through common techniques such as welding, hardware frame fasteners 131 , and the like. The lower lift frame 111 comprises the main lower support member to the mounting frame 110 and further comprises two plow horns 113 , two (2) stand hooks 114 , and at least two (2) lock pin apertures 128 . The mounting bracket 126 attaches thereto the front underside of a frame of the vehicle 100 via a plurality of mounting fasteners 127 which are envisioned as durable mechanical fasteners such as bolts or the like. A receiving bracket 125 is located subjacent thereto the mounting bracket 126 and comprises a hollow channel which is suitable to receive the plow horn 113 which is inserted therein. The mounting frame 110 is secured thereto the mounting bracket 126 once the plow horn 113 is inserted therein the receiving bracket via a lock pin 129 and the stand hook 114 . The lock pin 129 is inserted therethrough the aligned lock pin apertures 128 located thereon the lower lift frame 111 and the mounting bracket 126 . The stand hook 114 engages a round member thereon the mounting bracket 126 and provides added security and stability thereto the frame 110 . The upper lift fame 112 provides the main vertical support member thereto the mounting frame. The hydraulic lift 118 attaches thereto the upper lift frame 112 and provides the means of vertical lift thereto the louvered snow plow 10 via a lift ram 119 . The lift ram 119 attaches thereto a lift arm 120 which is rotatably attached thereto the upper lift frame 112 via a pin 130 . The hydraulic lift 118 drives the lift ram 119 thus raising or lowering the lift arm 120 . The lower lift frame 111 comprises an “A”-frame member 115 which attaches thereto the quadrant 70 and the mounting bracket 61 thereon the louvered snow plow 10 via the mounting bracket pin 69 and frame fasteners 131 . The mounting frame 110 further comprises two (2) angling rams 117 which attach thereto the rear surface of the louvered snow plow 10 thereat the hydraulic brackets 63 via the hydraulic bracket pins 65 . The angling ram 117 is envisioned as being a hydraulic shock absorber or as a hydraulically actuated member which may be used to manipulate the plowing angle of the louvered snow plow 10 as such should not be viewed as a limiting factor of the alternate embodiment of the present invention 10 . A means of electrically controlling the up-down motion therethrough the hydraulic lift 118 and the side-to-side motion therethrough the angling ram 117 is envisioned to be located therewithin the cab portion of the vehicle 100 and comprise features common to a controlled plow lift such as wiring, a control box, and the like (not shown). It is understood that portions of the mounting frame 110 may introduced a various configurations in order to accommodate various vehicle 100 designs and mounting requirements without affecting the scope and adding equal benefit thereto a user. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After initial purchase or acquisition of the apparatus 10 , it would be installed as indicated in FIGS. 1-4 . The method of installing and utilizing the apparatus 10 may be achieved by performing the following steps: removing an existing snow plow blade from an existing mounting frame 110 or installing a mounting frame 110 thereto a vehicle 100 ; retrieving a louvered snow plow 10 ; attaching the apparatus 10 thereto the existing mounting frame; pivotally attaching the mounting bracket 61 thereto the mounting frame 110 ; inserting a mounting bracket pin 69 therethrough the mounting bracket aperture 62 ; removably attaching the distal end of the quadrant 70 thereto an existing channel connection thereon the mounting frame 110 ; pivotally attaching each hydraulic bracket 63 thereto a hydraulic cylinder of the mounting frame 110 ; inserting a hydraulic bracket pin 65 therethrough the hydraulic bracket aperture 64 ; removably attaching each spring 68 thereto the mounting frame 110 ; positioning the apparatus 10 as desired for use via the hydraulic cylinders thereon the mounting frame 110 ; plowing snow as normal; and benefiting from the utilization of the present apparatus 10 . The method of installing and utilizing the alternate louvered snow plow 15 may be achieved by performing steps substantially similar to those described for the preferred apparatus 10 with the particular additions of the following steps: preparing the vehicle 100 for the attachment of the mounting frame 110 ; attaching the mounting bracket 126 thereto the front underside of the vehicle 100 via the mounting fasteners 127 ; inserting the plow horns 113 thereinto the receiving bracket 125 ; engaging the stand hooks 114 ; inserting the lock pin 129 therethrough the aligned lock pin apertures 128 ; plowing snow as normal; and, benefiting from the utilization of the present alternate louvered snow plow 15 . The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.

A snow plow blade with integrated multiple horizontal slats in lieu of one solid curved blade comprises a plurality of thin blades stacked upon one another in a staggered retreating arrangement from the bottom up. Should any blade damage occur, just the section damaged can be replaced by simply unbolting it and bolting on a new one. The slat structure allows air to flow through the blade while moving down the road and not plowing snow, enabling air to enter the radiator section of the vehicle to cool the radiator more efficiently. Finally, the slat structure is envisioned to create lift, in much the same manner as an airplane wing, thus making the blade appear lighter than its actual static weight when moving down the road and not plowing snow. This feature is envisioned to reduce wear and tear on suspension components, steering components, tires, and other similar items.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to apparatus employed at the intersection of two wires of opposite polarity in overhead electrically operated vehicle systems and more particularly relates to devices designed to prevent loss of power at such crossings. p 2. Description of the Prior Art: Electric trolley buses and similar vehicles obtain power from a pair of overhead electrical conducting wires, one positive and the other negative usually at a nominal direct current voltage of 600 volts. When a pair of wires diverges from the main path, a switch is installed which changes the path of the vehicle current collectors. In this switch one of the wires of one polarity must cross the other wire which is at the opposite polarity, To prevent a short circuit, insulators are placed in one of the wires which cross. If the current collectors take the direction through the switch that does not have the insulation, no interruption to current occurs. If the direction through the switch is the one with insulators, an interruption to current occurs and this is usually associated with arcing and burning as the trolley bus loses power. In some instances a trolley bus with insufficient speed can stop under the conventional crossing device, lose power and stall. The same consequences for operation through crossings exists as at switches. A variety of inventions addressing the difficulties encountered at these junctions are found in the prior art. For example U.S. Pat. Nos. 2,500,826, Hoover, discloses the use of short segments of standard trolley wire as replacement parts for crossovers; U.S. Pat. No. 2,727,102, Sawyer, describes a system for guiding vehicle current collectors past such crossings; and U.S. Pat. No. 2,802,072, Matthes, reveals a novel mechanical crossing assembly. U.S. Pat. No. 2,794,867 Sawyer, details a crossing device in which power of the correct polarity is applied to the intersection coupling or pan upon the approach of the vehicle. However in this invention no provision is made for the loss of power at the insulators which connect the overhead wires to the crossing unit. The invention disclosed herein provides a means by which power or current is always available to the vehicle at any point in the crossing. This is accomplished by the addition of an additional conducting strip along a portion of the insulators, means for powering such strips, and an improved switch for supplying power of the correct polarity to the crossing unit. SUMMARY OF THE INVENTION The invention may be summarized as a device for supplying constant current or power to vehicle current collectors at crossing points of wires of opposite polarity consisting of a conducting strip added to the overhead wire isolating insulators and appropriate associated circuitry. Diode means are provided in a connecting wire to power such strips with current of the correct polarity and a polarity changing switch employing gate turn off thyristors responsive to contactors positioned in proximity to the insulators is used to instantly set the crossing unit at the correct potential. Additionally, indicators for signaling the polarity of the crossing unit are provided and a choke coil is employed in the switch to prevent accidental shorting. The essence of the constant current wire crossing invention is the addition of conducting strips of the proper length to insulators of a standard size which exist in profusion in transit systems presently in operation. These strips are positioned such that as the vehicle current collecting shoe travels toward the crossing unit, power is continuously maintained. This is accomplished by the collector bridging first the primary wire and the conducting strip and then the conducting strip and the crossing unit. The conducting strip is powered by a connection to the crossing unit through a diode oriented to allow only power of the correct polarity to reach the conducting strip. As the vehicle moves past the crossing point, the order of contact is reversed through conducting strips on insulators on the opposite side. As the device is symmetrical it can accommodate the passage of vehicles from either direction. The invention, by providing constant current at a wire crossing alleviates the problems of power loss resulting in disabled vehicles and arcing and burning of contacts from power surges all of which are well known in the industry. The features and advantages of the invention will be more fully understood from the description of the preferred embodiment taken with the drawings which follows. DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of the preferred embodiment of the invention; FIG. 2 is an electrical schematic of one component of the device of FIG. 1; and FIG. 3 is an elevation view of an additional component of the device of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 there is shown in diagrammatic format the preferred embodiment of the invention applied to an intersection or crossing of a pair of electrical wires of opposite polarity as would be found in an overhead electrically operated vehicle system, for example a bus or trolley railway. As illustrated, the equipment consists of a crossing unit or pan 10, a pair of positive wires 12 and 12a and a pair of negative wires 14 and 14a, Each of the wires is attached to crossing unit 10 by an insulating runner 16 and 18; and 20 and 22 respectively. Each insulating runner has disposed thereon a conducting strip, of lesser length than the runner, 24 and 24a and 26 and 26a respectively. The conducting strips are electrically connected to the crossing unit in a manner which will be discussed in detail below. The operation and function of the various components described in terms of the passage of a vehicle current collecting shoe are as follows: Travel on the Positive Wire As the vehicle current collecting shoe passes from the positive wire 12 onto insulator portion 16a; current is received from positive wire 12. The shoe continues travel until it passes onto conducting strip 24, It now makes contact with both positive wire 12 and conducting strip 24 and it bridges insulating piece 16a. Current is received from wire 12 and strip 24 through connection 28, diode 30, crossing unit connection 32, and polarity change switch 34. The insulating pieces 16a,b; 18a,b; 20a,b; and 22a,b are of such length that they are slightly shorter than the carbon insert of the vehicle current collecting shoe so that the shoe will bridge the length of each insulating piece. This insures that the carbon of the shoe will always have some portion of it on an energized conducting surface. As the shoe passes onto conducting strip 24, it makes contact with contactor strip 36, actuating the negative turn off/positive turn on circuit of polarity change switch 34 making crossing unit 10 go to a positive polarity. As the shoe travels further, it leaves positive wire 12 and passes completely onto conducting strip 24, where it receives current through connection 28, diode 30, and crossing unit 10 through connection 32 from polarity change switch 34. The shoe travels from conducting strip 24 onto insulated piece 16b and further onto crossing unit 10. The shoe bridges insulating piece 16b and receives current from conducting strip 24, connection 28, diode 30, and crossing unit 10 through connection 32 and polarity change switch 34. When the shoe made contact with positive wire 12 and contactor strip 36, the polarity change switch 34 turned to positive polarity putting 600 volt direct current potential on crossing unit 10. Diode 38 prevents current from flowing out of crossing unit 10 to connections 46 and 48 and conducting strips 26 and. 26a. The shoe travels from crossing unit 10 onto insulating piece 18a and conducting strip 24a. Insulating piece 18a is bridged by the shoe so that the current flows from unit 10, to diode 30 through connection 40 to conducting strip 24a. Current is supplied by polarity change switch 34 to connection 32 to crossing unit 10. The shoe travels completely onto conducting strip 24a and makes contact with contactor strip 42 actuating the polarity change switch positive polarity circuit. Since it has been actuated as the shoe passed through contactor strip 36, this action is inconsequential but the symmetrical design of the unit allows for travel in both directions. The shoe travels from conducting strip 24a onto insulating piece 18b and positive wire 12a, The shoe bridges insulating piece 18b and receives current from positive wire 12a and conducting strip 24a through connection 40, diode 30, crossing unit 10, and connection 32 from polarity change switch 34. As the shoe leaves the crossing unit and passes onto positive wire 12acrossing unit 10 remains in the positive polarity and will remain so until a current collecting shoe traveling on the negative wire causes it to change polarity. Travel on the Negative Wire As the current collecting shoe passes from the negative wire 14 onto insulator 20 current is returned to negative wire 14. The shoe continues travel until it passes onto conducting strip 26. It now makes contact with negative wire 14 and conducting strip 26 and it bridges insulating piece 20a. As the shoe passes onto conducting piece 26, it makes contact with contactor strip 44, actuating the positive turn off/negative turn on circuit of polarity change switch 34 making crossing unit 10 go to a negative polarity. As the shoe travels further, it leaves negative wire 14 and passes completely onto conducting strip 26 where it returns current through connection 46 to diode 38, to crossing unit 10, through connection 32 to polarity change switch 34. The shoe travels from conducting strip 26 onto insulated piece 20b and crossing unit 10. The shoe bridges insulating piece 20b and returns current to conducting strip 26, connection 18 to diode 38 to crossing unit 10, to connection 32 to polarity change switch 34, When the shoe made contact with negative wire 14 and contactor strip 44, the drive unit turned off the positive polarity and turned on negative polarity for the crossing unit 10. Diode 30 prevents current from flowing from connection 28 and 40 and conducting strips 24 and 24a to the crossing unit 10. The shoe travels from crossing unit 10 onto insulating piece 22a and conducting strip 26a. Insulating piece 22a is bridged by the shoe so that current returns to crossing unit 10 and from connection 48 to diode 38 to crossing unit 10. Current returns to the polarity change unit 34 through connection 32. The shoe travels completely onto conducting strip 26a and makes contact with contactor strip 50 actuating the polarity change switch's negative polarity circuit. Since it has been activated as the shoe passed through contactor strip 44, this action is inconsequential but provides for travel in both directions. The shoe travels from conducting strip 26a onto insulating piece 22b and negative wire 14a. The shoe bridges insulating piece 22b and returns current to negative wire 14a and polarity change switch 34 through connection 48, diode 38, crossing unit, and connection 32 to the polarity change unit. As the shoe leaves the crossing unit and passes onto negative wire 14a, the crossing unit remains in the negative polarity and will remain so until a current collecting shoe on the positive wire causes it to change polarity. Operation of Polarity Change Unit Referring to FIG. 2, the polarity change switch 34 illustrated changes the polarity of the crossing unit from negative to positive and positive to negative as a current collector shoe bridges the respective contacts 36, 42, 44 or 50. Unit 34 consists of two gate turn off (GTO) thyristors, 52a, 52b each controlled by a gate drive unit 54a, 54b which is a commercially available device designed to control GTO thyristors. One GTO thyristor makes the crossing device positive and the other GTO thyristor makes it negative. The GTO thyristors are in conduction mode or turned on only when the gate drive unit is receiving a positive current from a voltage of 5 volts DC. When there is no voltage for operation of the gate drive unit, it turns off. Each gate drive unit is controlled by a silicon control rectifier (SCR) and two normally closed contacts of a relay controlled by operation of the opposite polarity gate drive unlit control. The respective SCR's are turned on by contacts 36, 42, 44 and 50 previously described. The cathode end of the positive GTO thyristor and the anode end of the negative GTO thyristor are wired in opposite turns on choke coil 56 which is connected to crossing unit 10. The choke coil prevents a short circuit should both thyristors be turned on simultaneously. A main fuse on the positive connection also protects against short circuit. Two light emitting diodes one red 58 for positive and the other green 60 for negative give an indication as to which polarity the crossing piece is in. When a vehicle shoe bridges contact 36 with positive wire 12, current flows through wire 62, through resistor 64, capacitor 66, C relay coil 68 to connection 70, to connection 72 at the negative wire. As the current flows, capacitor 66 charges up, C relay coil 68 is energized until capacitor 66 is fully charged, at which point current ceases to flow. Capacitor 66 is used to protect coil 68 from overheating should the current collector shoe stop on contact 36. As the current flows through relay coil 68 and energizes it, the relay operates and normally closed contacts C2 and C3 open while normally open contact C1 closes. This happens simultaneously. The action of contacts C2 and C3 opening causes a cessation of current flow for gate drive unit 54b so that it turns off. The cessation of current also causes silicon control rectifier 71 to turn off. As the gate drive unit 54b turns off, gate drive unit 54a turns on. This is accomplished by the closure of contact C1. Closure of this contact allows current to flow from the positive wire at connection 73 to 74 to 76, through fuse 78, resistor 80, and contact C1 to the gate of SCR 82. A gate trigger voltage of 5 volts turns on the SCR and current flows through capacitor 84, normally closed contacts D2 and D3 of relay D, through connection 70 and 72 to the negative wire 14. Current flows as the capacitor is charging. A positive voltage potential of 5 volts allows the gate drive unit 54a to turn on allowing current to flow through this device and through normally closed contacts D2 and D3, through connection 70 and 72 to the negative contact wire. At this time, the capacitor is fully charged and current ceases to flow through it. Gate drive unit 54a is turned on driving thyristor 52a. Gate drive unit 34b is turned off and thyristor 52b is not driven but is turned off so that no current can flow through it. With thyristor 52a turned on, positive current flows from the positive wire 12 through contact 73, 74, fuse 86 to thyristor 52a, through it and to the choke coil 56. Current flows through the choke coil, through connection 88 to the crossing unit. The device is now at 600 volts potential. When connection 88 is at 600 volts potential, current flows from it, through resistor 90, light emitting diode 58 connections 92, 94, 70, 72 to the negative wire. This causes LED 58 to glow red giving indication that the crossing unit is in the positive polarity mode. The crossing unit remains in this polarity mode until a vehicle current collector shoe passes through the device on the negative wire. When a shoe on the negative wire bridges contact 44 with negative wire 14, current flows from the positive wire through connection 73, 74, through fuse 96, resistor 98, capacitor 100, relay coil 102 to contact 44 and to the negative wire 14. As the current flows, capacitor 100 is charged up and as it is charging D relay coil 103 is energized until capacitor 100 is fully charged at which point current ceases to flow. Capacitor 100 is used to keep D relay coil 102 from overheating in the event a current collector shoe stops on contact 44. As the current flows through D relay coil 102 and energizes its the relay operates and normally closed contacts D2 and D3 open while normally open contact D1 closes. This happens simultaneously. The action of contacts D2 and D3 opening causes a cessation of current flow for gate drive unit 54a so that it turns off. The cessation of current also causes silicon control rectifier 82 to turn off. As gate drive unit 54a turns off, gate drive unit 54b turns on. This is accomplished by the closure of contact D1. Closure of this contact allows current to flow from the positive wire 12 to connection 73, through 74, 76, through connection 104 to 106, through fuse 108, resistor 110, contact D1, to the gate drive of SCR 71. A gate trigger voltage of 5 volts turns on SCR 71 and current flows through capacitor 112, normally closed contacts C2 and C3, through connection 94, connection 70 and 72 to the negative wire 14. Current flows as the capacitor is charging. A positive voltage potential of 5 volts allows the gate drive unit 54b to turn on allowing current to flow through this device and through normally closed contacts C2 and C3, through connection 94, 70, 72 to the negative wire 14. At this time the capacitor 112 is fully charged and current ceases to flow through it. Gate drive unit 54b is turned on and drives thyristor 52b. Gate drive unit 54a is turned off and thyristor 52a is turned off so that no current can flow through it. With thyristor 52b turned on, negative current flows from the crossing unit 10 through connection 32, through choke coil 56, through connection 114 through thyristor 52b to connection 92, to connections 94, 71, 72, to negative wire 14. With thyristor 52b turned on, light emitting diode 60 glows as current flows from the positive wire to connection 73, to connection 74, to 76, to 104, through resistor 116, through LED 60 to connection 114, through thyristor 52b to connection 92, to connection 94 to 70, 72, and to negative wire 14. LED 60 glows green giving indication that the crossing unit 10 is in the negative polarity mode. The crossing device remains in this polarity mode until a current collector shoe passes through the device on the positive wire. FIG. 3 is an elevational view of one of the insulators 16 and conducting strip 24 discussed above illustrating the physical construction of the unit. As variations in the above described embodiment will now be apparent to those skilled in the art, the scope of the invention is defined by the following claims.

A constant current wire crossing apparatus for overhead electrically operated vehicles, wherein wires of opposite polarity are connected by insulators to a crossing unit, including a conducting strip disposed on each insulator and appropriate switching circuitry such that a continuous source of power of correct polarity is available to a passing vehicle in any direction.

BACKGROUND The technical field of this disclosure relates to the general subject of fire-fighting, and more particularly to a reconnaissance apparatus and method for remotely identifying the location, flow rating and water pressure of fire hydrants within a local area. A fire hydrant, also known colloquially as a fire plug in the United States, provides a means for active fire protection as a source of water. Such apparatus are provided in most urban, suburban and rural areas with municipal water service to enable firefighters (responders) to tap into the municipal water supply to assist in extinguishing fires. One of the first challenges that responders face when they arrive at the scene of a fire is finding a suitable water source that provides enough water for the type of fire they face. In each situation, responders use standardized formulas to estimate the amount of water needed to suppress a fire. Fire hydrants are commonly color coded to indicate the maximum water flow rate they can provide in gallons per minute (GPM). Hydrant maximum water output varies from 500 GPM or less to over 2500 GPM depending on the supply system and the type of hydrant. In an effort to make it easier for responders to know what a specific hydrant will supply, the National Fire Protection Agency (NFPA) recommends that fire departments and water districts follow a set standard of color-coding. Hydrants using public water supply systems should be painted chrome yellow, and their tops and caps should indicate the available GPM. Recommended code includes: <500 GPM (red), 500-999 GPM (orange), 1000-1499 GPM (green), and ≧1500 GPM (blue). The Occupational Safety and Health Administration (OSHA) further recommends that a hydrant be painted violet for any source that is non-potable. If a hydrant is inoperable it is recommended that it be painted black. Hydrants are also rated in pressure units such as pounds per square inch (PSI). All hydrants are assumed to provide at least 20 PSI. If a given hydrant does not meet NFPA recommendations, the rated pressure should be stenciled on the top of the hydrant and on its caps. They also recommend this for extremely high pressure hydrants which can cause damage to firefighting equipment if precautions are not taken. Although the locations of fire hydrants are identified on maps, it may be difficult to locate or find a particular hydrant due to darkness, fog, mist, snow or surrounding vegetation. Also, a hydrant may be out of order or actually missing due to recent changes not portrayed on maps. Therefore, there is a need for improving the ability for fire fighters to quickly locate and characterize hydrants in the near vicinity of an existing fire. The presently described apparatus and method of use is an answer to this need providing the ability to locate and identify flow rate and pressure characterization of locally available hydrants quickly prior to arriving on the scene of a fire thereby saving precious moments and potential confusion as to which hydrant(s) to use, especially at night or at other times of low-visibility. It is known in the prior art to provide a fire hydrant strap-on solar powered device having lamps for signaling an emergency situation through selective colored beams and which may be activated by a responder wirelessly, and where color coding indicates the distance and direction of the hydrant from the transmitter and the hydrant flow rate and other hydrant characteristics. When a responder is approaching a fire it is important to enable fast reconnaissance of the vicinity of the fire. Therefore, it is important to know exactly where all fire hydrants are located relative to the fire and to also know the flow and pressure characteristics of the hydrants. The prior art does not provide a complete solution to this need. The present apparatus and method of operation provides an elegant, novel solution. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an example block diagram of the presently described apparatus; FIG. 2 is an example perspective view of an embodiment of a lighting set thereof; FIG. 3A is an example perspective view of a controller thereof; FIG. 3B is an example perspective view of an alternate controller thereof; FIG. 4 is an example block diagram of an electrical circuit thereof; FIG. 5 is an example perspective view of the lighting set mounted on a hydrant; FIG. 6 is an example perspective view of an alternate lighting set mounted on a hydrant; and FIG. 7 is an example logic flow diagram of a method of use of the alternate controller of FIG. 3B . Like reference symbols in the drawing figures indicate like elements. DETAILED DESCRIPTION As shown in FIG. 1 , the presently described reconnaissance system 10 includes one or more lighting sets 20 and a mobile controller 30 . Elements 20 and 30 communicate with each other via digital radio frequency (RF) transmission. The arrows in FIG. 1 represent wireless transmission channels. In an embodiment, the controller 30 sends RF signals to one or more lighting sets 20 and not signals are sent from sets 20 . In an embodiment shown in FIG. 2 , each lighting set 20 , may include a first electrical circuit 22 , a mounting band 24 having lamps 52 mounted on it, and a weather-proof enclosure 26 which encloses circuit 22 and has an integrated solar battery charger 40 . FIG. 5 shows band 24 with lamps 52 encircling hydrant 5 . Band 24 may have a series of mounting holes 25 any one of which may be mechanically secured inside enclosure 26 so as to adjust band 24 to fit tightly around hydrant 5 . Lamps 52 may be light emitting diode types (LEDs) which may be mounted to band 24 through small apertures 53 and may be electrically interconnected as shown using electrical conductors 57 on or within band 24 . In an embodiment shown in FIG. 6 , the enclosure 26 with circuit 22 and battery charger 40 may be mounted directly to hydrant 5 while band 24 with lamps 52 may be separately secured in place around hydrant 5 by a mechanical means of choice. The electrical block diagram of FIG. 4 represents the circuit 22 described above. As shown, circuit 22 may include the charger 40 , two rechargeable batteries 42 , and a digital RF transmitter 44 . The term “transmitter” as used herein shall mean not only an RF transmitter, but also an RF receiver or an RF transceiver. A digital microprocessor computer 46 with a digital memory 48 storing a computer process program 49 , a lamp driver 50 , and a plurality of the lamps 52 complete the circuit 22 . Charger 40 maintains batteries 42 at full charge. The several elements of circuit 22 are well known in the art. However, the combination of these elements and the arrangement thereof is considered to be novel and not obvious to one of skill in the art. When transmitter 44 receives an RF signal it provides a digital signal to microprocessor 46 directing it to initiate the process program 49 which then signals lamp driver 50 with a lamp operating code. Driver 50 then delivers voltage to lamps 52 illuminating them in a blink sequence rate according to the code. The program 49 may be pre-set to deliver an instruction to driver 50 to illuminate the lamps 52 in a blinking sequence representing the code as for instance, for hydrants 5 with at least 20 PSI water pressure, the lamps will blink constantly at a rate of two blinks per second. For hydrants 5 with less than 20 PSI water pressure, the lamps will blink more slowly, once per second, for example, and with hydrants 5 with a very high water pressure, the lamps will blink rapidly, for example, four times per second. Therefore, with lamp color and blink rate an appropriate hydrant may be quickly selected by a responder appropriate for a corresponding situation. In an embodiment of the reconnaissance system shown in FIG. 3A , the mobile controller 30 may include a circuit having a transmitter 44 , a battery 38 and a actuation button 35 for manual actuation of an RF signal. The signal may be received by transmitter 44 of the circuits 22 of one or more lighting sets 20 . The controller 30 may use a visor clip 34 to secure it within a responding vehicle 7 . In an embodiment of the reconnaissance system shown in FIG. 3B , the mobile controller 30 may be integrated into a commercial vehicular mobile navigator 9 such as the Garmin navigator shown. Such a satellite navigation system typically uses a GPS navigation device to acquire position data to locate the user and a user's destination on a road map in the unit's map database. Alternately, the mobile navigator 9 may use coordinates acquired from the cellular phone network to provide user and destination locations on a screen displayed map as illustrated in FIG. 3B . As previously discussed, the mobile controller 30 may include an RF digital transmitter 44 capable of transmitting an RF signal that is able to be received by an RF digital receiver 44 in lighting set 20 . Controller 30 may also include information in digital form concerning the GPS location, maximum flow rate, and water pressure, of every fire hydrant 5 within the geographical area served by a responder. This information may also include, for each hydrant 5 , a hydrant lamp color related to water flow rate and a lamp blink rate related to hydrant water pressure. When this information is integrated into the database of navigator 9 the navigator's microprocessor is able to display hydrant locations, color, and blink rate on screen, overlaying a street map of the destination (location of the fire). FIG. 7 shows the steps taken to achieve the hydrant display on the navigator's street map. In FIG. 7 we see that with the navigator 9 powered on, the user may enter a destination address whereupon the destination's GPS coordinates are retrieved from the navigator's database. The street map with the destination displayed at center is positioned. Next, the user enters a distance “d” that hydrants may located from the destination. This distance depends on the water pressure generally available to hydrants in the vicinity of the destination. There may be several hundred or even thousands of hydrants 5 in the geographical service area of a specific responder but there may be as few as only one hydrant 5 near enough to the destination to be useful. It is critically important for the responders to determine which hydrants 5 are available to the destination. As discussed, the hydrants within the geographical service area are stored in the navigator's database. As shown in FIG. 7 , each hydrant in the database is considered in sequence. The GPS location of each hydrant is compared with the GPS location of the destination and only hydrants having a distance “D” less than “d” are imaged on screen at their respective positions. In FIG. 3B there are six hydrants 5 shown. The hydrants 5 are shown as dots on screen and the dots are presented in a color representing the hydrant's maximum water flow rate. The dots are also presented with a blink rate representing water pressure as previously described. Such a navigator 9 typically is capable of displaying a selected area 3 of a city from data stored in its built-in or on-line digital memory. Also, a selected destination 8 , for instance a fire scene, may be displayed on screen by a mark as a circle with a dot at its center, for instance, as well as the present location of the responding vehicle 7 in which the navigator 9 is mounted. In an embodiment, fire hydrant location information is also stored in the memory of the navigator 9 and this information may be displayed on the screen as well. In an assigned response area of a given responder the locations of all fire hydrants 5 are known and are stored in the navigator's memory. The retrieval program is capable of displaying all hydrants 5 within a selected distance from a chosen fire scene 8 , for instance within 1000 feet. If the location is a building, the fire hydrants 5 along the frontal street and possibly the rear street may be displayed. If the fire scene is in a grass or wooded area, the hydrants 5 in surrounding streets are displayed. The data stored in memory, beside hydrant location 5 , may include hydrant operating characteristics such as flow-rate and water pressure rating. When a hydrant 5 is displayed on the screen of navigator 9 , the location may be identified by a dot ( 5 ) as shown, the water pressure by a blank rate of the dot ( 5 ), and the water pressure by the color of the dot ( 5 ). Other means for identifying hydrant characteristics may be employed as the foregoing is exemplary only. The important aspect is that, while in route to a fire scene, a preliminary reconnaissance may be completed so that entry to the scene and selection of a hydrant(s) may be made very quickly saving time, property, and potentially lives. In an embodiment, hydrant characteristics such as water pressure and flow rate may be stored in memory 48 of light set 20 , but may not be stored in the database of navigator 9 . Assuming that both controller 30 and lighting set 20 are equipped with RF transceivers 44 , when controller 30 transmits an RF signal, a response signal from set 20 will carry the hydrant characterizing information which is then received by controller 30 and displayed on the navigator's screen. In this approach, each hydrant 5 has a unique identification number. The responder transmits an RF signal with the identification number of a specific hydrant 5 . Only that hydrant responds. The responder has information of the hydrants 5 in the vicinity of the destination and is able to load each hydrant's identification number in each outgoing RF signal of a sequence of such signals. Embodiments of the subject apparatus and method have been described herein. Nevertheless, it will be understood that modifications by those of skill in the art may be made without departing from the spirit and understanding of this disclosure. Accordingly, other embodiments and approaches are within the scope of the following claims.

Fire hydrants each have a band of lamps strapped around them, the lamps powered by a solar collector battery circuit. An RF signal is transmitted to a receiver in the circuit by a remote responder causing the lamps to light up with a coded color related to the water flow rating of each of the hydrants and with a blink rate related to the water pressure of each of the hydrants. Upon arriving at the fire scene responders are able to select an appropriate hydrant for the location and size of the fire. The circuit is able to transmit flow and pressure information to the responders which information is presented on a display screen for early reconnaissance of the water resources at the fire scene.

CROSS REFERENCE TO RELATED PATENT APPLICATION [0001] This patent application is a continuation-in-part (CIP) of a U.S. patent application Ser. No. 10/047,762 filed Jan. 15, 2002, which is a continuation-in-part (CIP) of another U.S. patent application Ser. No. 09/946,094 filed Sep. 4, 2001, now both pending. The contents of the related patent applications are incorporated herein for reference. FIELD OF THE INVENTION [0002] The present invention relates to a control module of a rearview mirror of a vehicle, and more particular to a control module for automatically adjusting a view angle of a rearview mirror of a turning vehicle via a vehicular digital bus. Especially, the vehicular digital bus is a controller area network bus (CAN Bus) or a vehicle area network bus (VAN bus). BACKGROUND OF THE INVENTION [0003] For modern vehicles, to move has not been the only purpose any longer. People need faster, safer and more comfortable cars other than just vehicles. Therefore, various kinds of electronic apparatus are applied to the modern cars to conveniently lock/unlock the doors, operate the rearview mirrors, move the seats, switch on/off the headlamps, and etc. In addition, equipments such as defog heaters, air bags, stereo sound and speakers are becoming essential for general cars. Due to the presence of various electronic apparatus, the wiring in a vehicle is much more complicated than ever. Especially when all the electric assemblies located in different positions of a car have to be wired to a central computer, the required cables would be long, bulky and heavy. This will adversely effect the performance and the power consumption of the car. [0004] Therefore, in 1990, various bus systems are developed to communicate the electric assemblies so as to solve the wiring problems. A controller area network bus (CAN bus) or a vehicle area network bus (VAN bus) system is one of the most popular communication standards. By the arrangement of local computers and communicating the local computers via the CAN or VAN bus, the wiring can be localized and simplified. Accordingly, the required cables become short, light and neat. [0005] So far, the CAN bus system, although having been applied to the car to solve the wiring problem, is confined to the communication of basic electric assemblies. For some advanced functions, e.g. blind spot prevention by adjusting view angles of rearview mirrors upon turning, it still has to be additionally wired. SUMMARY OF THE INVENTION [0006] Therefore, an object of the present invention is to provide a control module, which can adjust the view angle of the rearview mirror by making use of the CAN or VAN bus. [0007] A first aspect of the present invention relates to a control module for adjusting the view angle of the rearview mirror. The control module is in communication with a vehicular digital bus and a monitor device of a vehicle, reads and decodes a digital encoded signal transmitted on the vehicular digital bus and corresponding to a turning operation of the vehicle, and adjusts a view angle of the monitor device according to the decoded information. [0008] Preferably, the vehicular digital bus is a controller area network (CAN) bus. [0009] In an embodiment, the digital encoded signal is asserted by another control module connected to the vehicular digital bus and an indicator light switch when the indicator-light switch is enabled. [0010] In another embodiment, the digital encoded signal is asserted by another control module connected to the vehicular digital bus and an indicator light when the indicator light is enabled to twinkle. [0011] For example, the monitor device can be a rearview mirror or a camera. [0012] A second aspect of the present invention relates to a monitor device control module for use with a vehicular control system. The vehicular control system comprises a plurality of control modules which control various electric assemblies, respectively, and are in communication with each other via a vehicular digital bus. The monitor device control module is in communication with the vehicular digital bus, reads and decodes a first digital encoded signal which is asserted by one of the control modules of the vehicular control system, transmitted on the vehicular digital bus and corresponds to a turning operation of the vehicle, and asserts a second digital encoded signal to adjust a view angle of a monitor device. [0013] In an embodiment, the monitor device is connected to a selected one of the control modules of the vehicular control system, and the selected control module reads and decodes the second digital encoded signal transmitted on the vehicular digital bus, and has the monitor device moved according to the decoded information. [0014] A third aspect of the present invention relates to a vehicular control system, which comprises a vehicular digital bus; a first control module in communication with the vehicular digital bus and an indicator light, and enabling the indicator light in response to a first vehicular digital signal asserted in response to an enabling operation of an indicator-light switch; and a second control module in communication with the vehicular digital bus, reading and decoding the first digital encoded signal, and adjusting a view angle of a monitor device according to the decoded information. [0015] In an embodiment, the second control module is connected to the monitor to adjust the view angle of the monitor device in response to the first digital encoded signal. [0016] In another embodiment, the second control module asserts a second digital encoded signal after reading and decoding the first digital encoded signal, and the first control module adjusts the view angle of the monitor device in response to the second digital encoded signal. [0017] Preferably, the indicator-light switch is connected to the first control module, and the first digital encoded signal is asserted by the first control module. [0018] Alternatively, the vehicular control system further comprises a third control module connected thereto the indicator-light switch, and asserting the first digital encoded signal when the indicator-light switch is enabled. BRIEF DESCRIPTION OF THE DRAWINGS [0019] The present invention may best be understood through the following description with reference to the accompanying drawings, in which: [0020] [0020]FIG. 1 is a schematic diagram showing a CAN bus system incorporating a preferred embodiment of a control module according to the present invention; and [0021] [0021]FIG. 2 is a schematic diagram showing a CAN bus system incorporating another preferred embodiment of a control module according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0022] The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only; it is not intended to be exhaustive or to be limited to the precise form disclosed. [0023] Referring to FIG. 1, a CAN bus system is illustrated. The CAN bus system includes a CAN bus 10 and a plurality of local control modules M 1 , M 2 , . . . Mn connected to the CAN bus 10 in parallel for controlling various electric assemblies 110 , 111 , 113 , 114 via the bus 10 , respectively. For example, the local control module M 1 is disposed around the front left door, and controls the moving assembly of the front left seat, the defog heater of the left exterior rearview mirror, the left indicator light, the left-side airbag and the left speakers, and centrally controls all the door locks, all the windows, the moving assemblies of the exterior rearview mirrors, etc., if the left side is the driver's side. The local control module M 2 is disposed around the driver's seat, and controls the indicator-light switch, the headlamps, the driver's airbag, the horn, etc. The local control module M 3 is disposed at the front right side, and controls the moving assembly of the front right seat, the defog heater of the right exterior rearview mirror, the right indicator light, the passenger's airbag and the right speakers. [0024] The number of local control modules is not particularly stipulated, but aims to simplify the wiring. Those local control modules are electrically connected to the CAN bus 10 , and transmit signals on the CAN bus to control respective electric assemblies. For example, when the driver is going to turn the car left, he will move the indicator-light switching stick 110 downwards. Meanwhile, the control module M 2 asserts a digital encoded signal corresponding to the downward movement of the switching stick 110 to the bus 10 . The digital encoded signal is transmitted on the bus 10 and selectively received by an associated control module, i.e. the control module M 1 connected thereto the left indicator light 111 in this example. Upon receiving the digital encoded signal corresponding to the downward movement of the switching stick 110 , the control module M 1 decodes the digital encoded signal to operate the left indicator light 111 , i.e. twinkle the indicator light 111 . [0025] According to the present invention, an additional control module M 0 is provided to automatically adjust the view angle of the rearview mirrors. The control module M 0 is connected to the bus 10 in parallel with the control modules M 1 ˜Mn, and connected to the left rearview mirror 113 and the right rearview mirror 114 . The control module is designed to recognize the digital encoded signals associated with the operation of the left and right indicator lights. For example, when the control module M 2 asserts a digital encoded signal corresponding to the downward movement of the switching stick 110 to the bus 10 , as in the above example, the control module M 0 also reads and decodes the digital encoded signal on the bus 10 and realizes that the left indicator light 111 is enabled. Meanwhile, the control module M 0 enables the left exterior rearview mirror 113 to turn outwards from an initial position to a predetermined position, thereby enlarging the view angle of the turning side. Subsequently, when the switching stick 110 recovers to the initial position manually or automatically, the control module M 2 stops asserting the digital encoded signal or asserts another digital encoded signal corresponding to the recover of the switching stick 110 , the control module M 1 stops the twinkling operation of the indicator light 111 , and the control module M 0 enables the rearview mirror 113 to recover to its initial position. [0026] Likewise, when the control module M 2 asserts a digital encoded signal corresponding to the upward movement of the switching stick 110 to the bus 10 , both of the control modules M 3 and M 0 read and decode the digital encoded signal on the bus 10 . The control module M 3 enables the right indicator light 115 to twinkle, and the control module M 0 enables the right exterior rearview mirror 114 to turn outwards from an initial position to a predetermined position, thereby enlarging the view angle of the turning side. On the other hand, when the switching stick 110 recovers to the initial position manually or automatically, the control module M 2 stops asserting the digital encoded signal or asserts another digital encoded signal corresponding to the recover of the switching stick 110 , the control module M 1 stops the twinkling operation of the indicator light 115 , and the control module M 0 enables the rearview mirror 114 to recover to its initial position. [0027] Alternatively, the two rearview mirrors may be turned together. For example, when the car is turning left, both of the rearview mirrors are turned counterclockwise to enlarge the view angle of the left side. On the contrary, when the car is turning right, both of the rearview mirrors are turned clockwise to enlarge the view angle of the right side. Moreover, in addition to moving from an initial position to a predetermined position, the rearview mirror can also perform an sweeping operation during turning. This can be achieved by revising the programs of the control module M 0 . [0028] In another embodiment, two control modules similar to the control module M 0 can be used to control the left and the right rearview mirrors, respectively. One of the control modules is connected to the bus 10 and the left rearview mirror 113 , and the other is connected to the bus 10 and the right rearview mirror 114 so as to reduce the length of the cables. [0029] In another aspect, the control module M 0 can also move the rearview mirror 113 or 114 according to the digital encoded signal asserted by the control module M 1 instead of M 2 . In other words, when the control module M 1 reads the digital encoded signal corresponding to the downward movement of the switching stick 110 , the control module M 1 decodes the digital encoded signal and asserts another digital encoded signal to operate the left indicator light 111 . The control module M 0 reads and decodes the digital encoded signal asserted by the control module M 1 , and enables the rearview mirror 113 or 114 to move according to the decoded information. [0030] The above embodiment is illustrated by connecting the control module M 0 to the CAN bus system. It is understood, however, the present control module can also be used with other vehicular digital bus systems to achieve the same purpose. Further, aside from rearview mirrors, the angles of other monitoring devices such as CCD or CMOS cameras or back-up radars can also be properly adjusted by the same or different control modules similar to the above-mentioned ones. Moreover, in addition to the embodiment that the control modules are “connected” to the CAN bus, the control modules can also transceive signal through the bus via a wireless transmission mode. [0031] Please refer to FIG. 2 which is a schematic diagram showing a CAN bus system incorporating another preferred embodiment of a control module according to the present invention. In this embodiment, the indicator-light switching stick 210 , as well as the left indicator light 211 and the left rearview mirror 213 , is connected to the control module M 1 . The right indicator light 215 and the right rearview mirror 214 are connected to the control module M 3 . Further, all the local control modules M 1 ˜Mn are connected to the CAN bus 20 . The control module M 0 additionally provided according to the present invention is connected to the CAN bus 20 alone, and not connected to the left and/or right rearview mirrors. [0032] When the driver is going to turn the car left, he will move the indicator-light switching stick 210 downwards. Meanwhile, the control module M 1 asserts a first digital encoded signal corresponding to the downward movement of the switching stick 210 to the bus 20 for the reference of other control modules. In general, the control modules M 2 ˜Mn will not respond to the first digital encoded signal because the left indicator light 211 to respond to the first digital encoded signal is connected to the control module M 1 rather than the control modules M 2 ˜Mn. Upon receiving the first digital encoded signal corresponding to the downward movement of the switching stick 210 , the control module M 1 decodes the first digital encoded signal to operate the left indicator light 211 , i.e. twinkle the indicator light 211 . [0033] The control module M 0 according to the present invention, however, will recognize the first digital encoded signal, decode the first digital encoded signal, and assert a simulated second digital encoded signal recognized by the control module M 1 to the bus 20 . When the control module M 1 detects the second digital encoded signal on the bus 20 , the second digital encoded signal is read and decoded by the control module M 1 to adjust the view angle of the rearview mirror 213 . Subsequently, when the switching stick 210 recovers to the initial position manually or automatically, the control module M 1 stops asserting the first digital encoded signal or asserts a third digital encoded signal corresponding to the recover of the switching stick 210 . If the third digital encoded signal corresponding to the recover of the switching stick 210 is asserted by the control module M 1 , the control modules M 2 ˜Mn will still not respond to the third digital encoded signal, but the control module M 0 will. The control module M 0 will assert a simulated fourth digital encoded signal recognized by the control module M 1 to the bus 20 in order to recover the left rearview mirror 213 to its initial position. [0034] The indicator-light switching stick 210 as mentioned above is connected to the control module M 1 . Alternatively, it can also be connected to the control module M 3 . [0035] In the above embodiments, the purpose for automatically adjusting the view angle of the rearview mirror upon turning can be achieved by additionally mounting the present control module M 0 to the existing CAN bus system. Of course, the same purpose can also be achieved by modifying the existing CAN bus system to incorporate at least the following functions therein. [0036] (i) When detecting that a digital encoded signal to enable the left indicator light is transmitted on the bus, the left rearview mirror turns counterclockwise from an initial position to a predetermined position; [0037] (ii) When detecting that a digital encoded signal to enable the right indicator light is transmitted on the bus, the right rearview mirror turns clockwise from an initial position to a predetermined position; [0038] (iii) When detecting that a digital encoded signal to disable the left indicator light is transmitted on the bus, the left rearview mirror turns clockwise from the predetermined position to its initial position; and [0039] (iv) When detecting that a digital encoded signal to disable the right indicator light is transmitted on the bus, the right rearview mirror turns counterclockwise from the predetermined position to its initial position; [0040] From the above description, the rearview mirror can be automatically adjusted in response to the turning operation via the advanced vehicular digital bus system, e.g. the CAN bus system. By additionally mounting a rearview mirror control module like the above-mentioned control module M 0 , a common car can have the advanced rearview mirror control function as a deluxe car. [0041] The above embodiments, in spite of being illustrated by using a CAN bus system, it is understood the present invention can be implemented by way of any other suitable vehicular digital bus, e.g. a vehicular area network bus (VAN bus). [0042] While the invention has been described in terms of what are presently considered to be the most practical and preferred embodiments, it is to be understood that the invention need not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.

A control module for adjusting the view angle of a rearview mirror via a controller area network (CAN) bus is disclosed. The control module is connected to a CAN bus and a rearview mirror of a vehicle. Upon reading and decoding a digital encoded signal which is transmitted on the vehicular digital bus and corresponds to a turning operation of the vehicle, the control module adjusts a view angle of the monitor device according to the decoded information.

RELATED APPLICATIONS [0001] This application claims priority of U.S. Provisional Application Nos. 60/341,349, filed Dec. 18, 2001 and 60/374,754, filed Apr. 23, 2002. These earlier provisional applications are hereby incorporated by reference. FIELD OF THE INVENTION [0002] This invention relates to a CDR-derived polypeptide from monoclonal antibody 13B8.2, pharmaceutical compositions made therefrom and methods of treating mammals with selected disorders. BACKGROUND [0003] The CD4 molecule is a transmembrane glycoprotein of 58 kDa mainly expressed on the surface of mature T cells [1, 2]. CD4 is composed of four extracellular domains (D1-D4), which share homology with the immunoglobulin V k region [3, 4], a transmembrane portion and a cytoplasmic tail non-covalently associated with the protein tyronsine kinase p56 lck [5]. The CD4 molecule acts as co-receptor for the major histocompatibility complex (MHC) class II and is a molecular partner for the T cell receptor (TcR) [6-9]. This trimolecular complex is critical for optimal activation of T cells [10-12]. Besides this physiological function, CD4 serves as a receptor for envelope glycoprotein of the human immunodeficiency virus (HIV), contributing to virus entry into cells [13]. [0004] Interactions with both MHC class 11 and gpI20 involve residues of the complementarity determining region (CDR)2-like loop in D1 of CD4[14-18]. On the opposite side of the D1 domain of CD4, the CDR3-like loop displays biological activities by acting as a target for molecules that inhibit immune response and HIV replication [19-22]. This latter role in a cascade of postbinding events has been demonstrated both by CDR3-like peptide analogs [23-27] and by anti-CDR3-like monoclonal antibodies (mAbs) such as 13B8.2 mAb [28-30]. The biological properties of 13B8.2 mAb have lead to its inclusion in phase I/II trials of HIV-infected patients. Those clinical trials using the anti-CD4 mAb 13B8.2 triggered a strong immune response to the mouse antibody, leading to a decrease in biological effects [31-33]. [0005] Clinical applications of full-length murine mAbs may be limited by their high immunogenicity, their inability to cross the blood/brain barrier, and their limited ability to penetrate cells and tissues [34]. To overcome such problems, recombinant DNA technology has been applied to redesign these foreign antibody molecules, making them more human-like, by chimerization [91] or humanization [92]. Although various systems have been described [93], the expression of complex proteins such as antibody molecules in the baculovirus/insect cell system offers marked advantages with respect to post-translatinal modifications, stability, yields and applicability. As far as we know, insect cells and baculovirus are devoid of pathogenic or toxic compounds for humans. Moreover, insect cells can be grown in protein-free medium, i.e., without mammalian contaminants, leading to easy and safe purification. These latter characteristics offer a strong advantage over the other systems for immunotherapeutic purposes. We previously described the construction of two cassette-transfer vectors for the expression and the secretion of complete chimeric IgG1 [94, 95] in insect cells infected with a double-recombinant baculovirus. SUMMARY OF THE INVENTION [0006] This invention relates to an isolated CDR-derived polypeptide from monoclonal antibody 13B8.2. [0007] This invention also relates to pharmaceutical compositions including a pharmaceutically acceptable carrier and at least the peptide described above. [0008] This invention further relates to a method for treating a subject suffering from an autoimmune disorder, including administering to the subject a therapeutically effective amount of the pharmaceutical composition described, a method for treating a subject suffering from a transplant rejection including administering to the subject a therapeutically effective amount of the pharmaceutical composition, a method for treating a subject suffering from an HIV immunodeficiency disorder including administering to the subject a therapeutically effective amount of the pharmaceutical composition and a method for treating a subject suffering from a tumoral disorder including administering to the subject a therapeutically effective amount of the pharmaceutical composition. BRIEF DESCRIPTION OF THE DRAWINGS [0009] [0009]FIG. 1 is a graph of protein content versus elution volume. [0010] [0010]FIG. 2 is a graph of inhibition of 13B8.2 mAb/CD4 binding (%) as a function of recombinant Fab 13B8.2 (nM). [0011] [0011]FIG. 3 is a graph of BIAcore binding analysis curves with response (RU) as a function of time (s). [0012] [0012]FIG. 4 is an epitoped characterization of recombinant Fab and mAb 13B8.2 in accordance with the Spot method. [0013] [0013]FIG. 5A is the inhibition percentage of IL2 secretion by pdb10fT cells sensitized with PEP 24-stimulated EBV-Lu cells and co-cultured with inhibitor antibodies. [0014] [0014]FIG. 5B is a graph of the inhibition percentage of LTR-driven β-galactosidase gene expression induced by HIV-1 lai following incubation with inhibitor antibodies. [0015] [0015]FIG. 6 is the acid amino sequences of V H and V L domains of the anti-CD4 mAb 13B8.2. [0016] [0016]FIG. 7 shows a quantitative analysis of the binding of biotinylated-rhCD4 to overlapping dodecapeptides derived from the variable sequences of anti-CD4 13B8.2 mAb. [0017] [0017]FIG. 8 is a graph showing the ELISA binding assay of His 6 -sCD4 onto absorbed cyclic peptides derived from the sequence of 13B8.2. [0018] [0018]FIG. 9 is a graph of the epitope specificity of the binding of PDPs CB1 and CB8 to sCD4 with inhibition of CD4 binding to PDPs as a function of 13B8.2 mAb concentration. [0019] [0019]FIG. 10A is a graph of the percent inhibition of β-galactosidase activity induced by HIV-1 lai following incubation with cyclic PDPs. [0020] [0020]FIG. 10B is a graph of Dose response curves for HIV-1 lai infected HeLa P4 cells cultured in the presence of various concentrations of 13B8.2 mAb and PDP CB1 in the form of percent inhibition of β-galactosidase activity as a function of inhibitor concentration. DETAILED DESCRIPTION [0021] We developed the concept of paratope-derived peptides (PDPs) which correspond to short amino acid sequences derived from antibody variable regions and which display antigen binding and biological activities [35-38]. These small molecules are screened from a systematic exploration or antibody variable domain sequences by the Spot method [39,40]. Given the pharmaceutical interest of 13B8.2 mAb, it appeared to us attractive to design such anti-CD4 PDPs. [0022] To this end, we chimerized the 13B8.2 mAb as a recombinant Fab fragment expressed in the baculovirus/insect cell system. The recombinant chimeric Fab 13B8.2 displays similar CD4-binding and immunosuppresive properties as the parental mouse mAb. These functional effects of chimeric Fab 13B8.2 make it a good candidate for therapeutic purposes. Therapies of particular interest include, but are not limited to, autoimmune disorder, transplant rejection, HIV immunodeficiency disorder and tumoral disorder. Preferred autoimmune disorders include, for example, psoriasis, rheumatoid arthritis and lupus arythematosus. Specifically, we identified nine PDPs from the 13B8.2 variable regions by using the Spot method. All the selected PDPs, prepared in a soluble cyclic form, were able to bind histidine-tagged recombinant CD4 (His 6 -sCD4) expressed in baculovirus. MAb 13B8.2 specifically displaced the binding of His 6 -sCD4 to PDPs CB1 and CB8, indicating that anti-CD4 PDPs recognize an epitope on the CD4 molecule closely related or similar to that identified for the 13B8.2 parental mAb. PDP CB1 displayed biological properties very similar to those of the parental 13B8.2 mAb, inhibiting in vitro antigen presentation and HIV-1 promoter activation. Taken together, we believe that the bioactive PDP CB1, derived from the CDR-H1 region of the anti-CD4 13B8.2 mAb, is valuable for anti-CD4 peptidomimetics. Materials [0023] Reagents, Cell Lines and Vectors [0024] Recombinant human soluble CD4 (rhCD4) was obtained from Repligen (Needham, Mass., USA). rhCD4 was biotinylated using a commercial reagent (Amersham Pharmacia Biotech, Cleveland, Ohio, USA) according to the manufacturer's instructions and stored in PBS at −20° C. until use. 13B8.2 mAb [19,31] was obtained from Immunotech-Coulter (Marseille, France). The murine hybridoma cell line that produces 13B8.2 mAb (IgG1/κ[19]) was provided by Dr. D. Olive and Dr. C. Mawas (INSERM U119, Marseille, France). The pMV7-T4 plasmid, encoding the full-length CD4-cDNA sequence [41,42], was provided by Dr. Q. J. Sattentau (Centre d'Immunologie de Marseille-Luminy, Marseille, France). The human lymphoblastoid B cell line EBV-Lu, expressing the HLA DR5,6, DRB52, DQ6,7, and A2 molecules, and the murine T cell pdb10F, expressing human CD4 and pep24 (PAGFAILKCNNKTFNY)-specific chimeric TcR, have been previously characterized [43,44] were provided by P. DeBerardinis (Consiglio Nazionale delle Ricerche, Napoly, Italy). The HeLa P4 HIV-1 LTR β-galactosidase indicator cell line [45] was provided by Dr. O. Schwartz (Institut Pasteur, Paris, France). EXAMPLE 1 [0025] Baculovirus Expression of Recombinant CD4 [0026] The nucleotide sequence of soluble CD4 (D1-D4) was sorted by PCR from the pMV7-T4 plasmid, then cloned into the p119L baculovirus transfert vector to allow the expression of CD4 under the P10 promoter, as described elsewhere except that no histidine tag was inserted in the construction. Transfection of Sf9 cells and further expression of CD4 in baculovirus supernatant was performed [94, 95]. An enriched-CD4 fraction was prepared following 80% ammonium sulphate precipitation of the baculovirus supernatant and subsequent dialysis in a 0.1×160 mM PBS solution. [0027] Construction of Recombinant Baculovirus Producing the Chimeric Mouse/Human Anti-CD4 Fab 13B8.2 [0028] The general procedures concerning the cloning and sequencing of 13B8.2 mAb variable regions have been described [99]. Two plasmid cassette-transfer vectors pBHuCk and pBHuFDγ1 were constructed that contain the human Cκ gene [94] and the first domain of human Cγ 1 (Fdγ 1 ), allowing the insertion and expression of variable heavy (VH and kappa light (Vκ) chains of the anti-CD4 mAb 13B8.2 under the control of the polyhedrin and p10 promoter: pBHuFdγ 1 was obtained by using the same procedure as that described by Poul et al. [94] for the construction of the pBHuCγ 1 plasmid vector except that a stop codon was inserted at the end of the gene encoding for the first domain of the Cγ 1 constant region. A two-step recombination procedure [94, 95] was carried out to construct the recombinant baculovirus, named 5756, expressing both heavy and light chains of the chimeric Fab 13B8.2. [0029] Anti-CD4 Fab 13B8.2 Production and Purification [0030] A 400 ml-supernatant of Spodoptera frugiperda Sf9 cells (ATCC CRL 1711) infected with the recombinant baculovirus 5756 in a spinner culture 10 6 cells/ml) was recovered 96-h post infection and precipitated with a saturated ammonium sulphate solution until 80% saturation. After centrifugation at 10,000 g for 30 min, the pellet was dissolved in 160 mM PBS, pH 7.2, and extensively dialyzed against PBS. The antibody solution, diluted v/v with 100 mM sodium acetate buffer, pH 5.0, was filtered (0.22 μm) and applied to a protein-G column )(Pierce, Rockford, Ill.) which has been equilibrated with 100 mM sodium acetate buffer, pH 5.0. Bound recombinant Fab 13B8.2 was eluted with 50 mM Glyciner-HCl buffer, pH 2.5, and immediately neutralized to pH7 with a 0.2 M Tris solution, pH 10.5. The protein content was monitored at 280 nm and purification fractions were checked for anti-CD4 activity by ELISA as described below. Samples were analyzed under reducing and non-reducing conditions on 12.5% polyacrylamide gel, according to the Laemlli procedure [100]. Proteins were subsequently transferred to a nitrocellulose membrane (Hybond ECL, Amersham Pharmacia Biotech) and detected with a peroxidase-conjugated anti-human kappa chain (Sigma) and a sheep anti-human Fdγ 1 (The Binding Site, Birmingham, UK) by using the ECL detection kit (Amersham Pharmacia Biotech). [0031] Peptide Synthesis on Cellulose Membrane Covering the D1 Domain of CD4 [0032] The general protocol has been described previously [101]. By the Spot method, we synthesized 98 overlapping dodecapeptides frameshifted by one residue, representing the D1 domain of the CD4 molecule, on a cellulose membrane. [0033] Assay for Recombinant Fab 13B8.2 Interaction with Cellulose-Bound Peptides Covering the D1 Domain of CD4 [0034] The saturated membrane was incubated either with a 6.25 nM solution of mouse mAb 13B8.2 or with a 50 nM solution of recombinant Fab 13B8.2 for 2 h at 37° C. Bound antibodies were detected with a 1:500 solution of either peroxidase-labeled anti-mouse IgG conjugate (Sigma, saint Louis, Mo.) or peroxidase-labeled anti-human kappa chain conjugate (Sigma), followed by ECL revelation (Amersham Pharmacia Biotech). [0035] Binding Studies of Recombinant Fab 13B8.2 to CD4 [0036] A 1:500 dilution of the enriched-CD4 fraction in 0.1 M carbonate/bicarbonate buffer, pH9.6, was coated overnight at 4° C. onto 96-well enzyme immuno assay plates (Nunc, Paisley, United Kingdom). Four washes with 160 mM PBS, pH 7.2, containing 0.1% Tween 20 (PBS-T) were performed before and after saturating plates in 1% nonfat powdered milk in PBS-T for 1 h at 37° C. Thereafter, 100 μl of two-fold serial dilutions of the antibody solution was added to each well. Following incubation of 2 h and four washes in PBS-T, bound antibodies were detected by addition of 100 μl of a 1:1000 solution of peroxidase-conjugate anti-mouse IgG (Sigma) or peroxidase-conjugated anti-human kappa chain (Sigma), followed by subsequent addition of peroxidase substrate. Absorbance was measured at 490 nm (A490). For the inhibition of CD4 binding to mouse mAb 13B8.2 by recombinant Fab 13B8.2, a similar ELISA method was performed except that 13B8.2 mAb, at a 6.25 nM concentration giving an A490 of 1.0, was co-incubated with 2-fold serial dilutions of recombinant Fab 13B8.2. Three replicates were tested for each dilution with an initial Fab concentration of 1 μM. CD4/13B8.2 mAb residual binding was evaluated as described above. [0037] The kinetic parameters of the binding of CD4 to 13B8.2 antibody were determined by surface plasmon resonance analysis using a BIAcore instrument (BI-Acore AB, Uppsala, Sweden). In an initial experiment, CD4 was immobilized on a CM5 sensorchip and 100 nM Mab 13B8.2 or recombinant Fab in HBS buffer (10 mM Hepes pH 7.6, 150 nM NaCl) were then injected. In a second experiment, 400 nM recombinant Fab were immobilized on a CM5 sensorchip by using the anti-human Fdγ 1 conjugate (The Binding Site). The binding kinetics were determined by injecting various concentrations of CD4 in HBS buffer. The kinetic parameters were calculated by using the BIA evaluation 3.0 software and the so-called “global” method [102]. [0038] IL-2 Secretion Assay Following Antigen Presentation [0039] The EBV-Lu antigen-presenting cells (APC) were maintained in RPMI medium (BioWhittaker, Walkersville, Md.) supplemented with 10% FCS, 2 mM glutamine and 100 μg/ml penicillin/streptomycin (Sigma). Responder pdb10F T cells were maintained in DMEM medium (Gibco, Paisley, United Kingdom) supplemented with 10% fetal calf serum (FCS), 50 nM 2-mercaptoethanol, 10 nM HEPES, 2 mM glutamine, 100 μg/ml penicillin/streptomycin and kept under selection with 400 nM methotrexate and 900 ng/ml puromicine (Sigma). EVB-Lu cells (10 6 cells/ml) were pulsed overnight at 37° C. with the pep24 stimulator peptide (75 μM) from HIV gp120 [97]. Cells were washed in PBS buffer without Ca 2 +and Mg 2 +(Biowhittaker) and plated at 10 5 cells/well. Pdb10F reporter cells were washed with the same PBS buffer, diluted in DMEM medium without methotrexate and puromycin to a final concentration of 4×10 5 cells/ml. 50 μl of cell suspension were plated onto EBV-Lu cells. Fifty microliters of inhibitor antibodies were then added to cells and antigen presentation was performed for 24 h at 37° C. Thereafter, 100 μl of supernatant was harvested and tested for IL-2 secretion using a commercial ELISA kit (Pharmingen, San Diego, Calif.). A positive control assay for IL-2 secretion was performed as described above except that the pdb10F cells were activated using a murine anti-CD3 antibody (0.6 nM, Pharmingen). [0040] HIV-1 Promoter Activation Assay [0041] HeLa P4 indicator cells (8×10 4 cells/ml) were cultured in medium supplemented or not with infectious HIV-1 Lai in the presence or absence of antibodies for three days, harvested and lysed. β-galactosidase activity was then determined as previously described by measuring the absorbance at 410 nm [98]. [0042] Expression, Secretion and Purification of the Recombinant Fab 13B8.2 from Baculovirus-Infected Insect Cells [0043] The nucleotide sequences of the VH and VL domains of 13B8.2 mAb (accession numbers AJ279001 and 279000) have been previously established according to the general procedure described by Chardè et al. [99]. Genetic analysis of these sequences [99] showed that the VH region of 13B8.2 mAb resulted from the rearrangement of VH2-DQ52-JH3 genes and that the VL region resulted from a Vκ12/13-Jκ2 gene rearrangement. In the recombinant baculovirus designated 5756, the chimeric Cκ-Vκ 13B8.2 and Fdγ 1 -VH13B8.2 genes are under the control of the very late polyhedrin and p10 promoters, respectively. Recombinant Fab 13B8.2 was protein-G immunopurified from 400 ml of supernatant, obtained 96 h post infection of insect cells with 5756 baculovirus (FIG. 1). The wash fractions 1 to 10 revealed a decrease in protein content with no detectable anti-CD4 activity, whereas eluted fractions 14 to 18 showed strong anti-CD4 activity in correlation with an increase in protein content. [0044] These fractions were further pooled for antibody analysis by Coomassie blue SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting (FIG. 1, inset). Coomassie blue SDS-PAGE revealed a single band at 50 kDa, corresponding to the expected size of a correctly-processed Fab under non-reducing conditions (FIG. 1, lane 1). No other band was observed by Coomassie blue staining, demonstrating the quality of the protein-G immuno purification. The identity of the 50-kDa band was confirmed by western blotting using anti-human K chain (FIG. 1, lane 2) or anti-human Fdγ 1 chain (FIG. 1, lane 4). Individually-expressed heavy and light chains were not detected by western blotting following non-reduced SDS-PAGE. Reduction of the purified recombinant Fab 13B8.2 generated one band of approximately 25 kDa, detected by using anti-human κ chain (Fib. 1, lane 3), and one band around 28 kDa, detected by using anti-human Fdγ 1 chain (FIG. 1, lane 5). Taken together these results indicate that the anti-CD4 recombinant Fab 13B8.2 produced in the baculovirus/insect cell system is correctly assembled and secreted in the supernarant as a dimeric HL complex. The yield of purified baculovirus-expressed Fab 13B8.2 was about 5 mg/L. [0045] Baculovirus-Expressed Chimeric Fab 13B8.2 Specifically Binds the CD4 Molecule [0046] The ability of recombinant Fab 13B8.2 to bind CD4 was assessed by an ELISA method (FIG. 2) and by BIA-core analysis (FIG. 3). By ELISA, CD4 binding activity was demonstrated for a chimeric Fab concentration in the 10-1000 nM range (FIG. 2, inset), whereas no binding was obtained with the irrelevant baculovirus-expressed Fab 1C10 (data not shown). Control mAb 13B8.2 displayed CD4 binding in the 1-100 nM range (FIG. 2, inset). By using BIAcore technology (FIG. 3), CD4/Fab interaction was confirmed with a K D value of 3.3 nM, whereas the affinity of the parental mAb was about 2.5 nM. This Fab interaction was CD4 dose-dependent (FIG. 3, inset). No measurable finding was obtained with the irrelevant Fab 1C10 (data not shown). Finally, the recombinant Fab 13B8.2 was able to displace the binding the parental mAb to CD4 in a dose-dependent manner (FIG. 2). A 50% inhibition of binding was obtained for a Fab concentration of 80 nM. These results indicated that the baculovirus-expressed Fab 13B8.2 finds the CD4 molecule on the same region as the parental antibody. Furthermore, the same CDR3-like region 87EDQKEEVQLLVFGLTA102 on the D1 domain of CD4 was identified as the binding region of the fragment and the intact antibody products, as shown by Spot analysis (FIG. 4), definitively demonstrating that a similar epitope is recognized by the mouse parental antibody and the recombinant Fab. No spot reactivity was observed with dodecapeptides covering the other regions on the D1 domain of CD4. [0047] Baculovirus-Expressed Chimeric Fab 13B8.2 Displays Immunosuppressive Biological Properties [0048] The stimulation of pdb10f responder T cells by pep24-pulsed EBV-Lu APC leads to the lymphocyte secretion of IL2[97]. This T cell activation model was found to be specific since no IL-2 secretion occurred when EBV-Lu antigen-presenting cells were pulsed with a non-stimulator pep23 antigen. The viability of pdb10f responder cell line was checked by activating cells with a murine anti-CD3 mAb which induced IL-2 secretion. As shown in FIG. 5(A), 7.8 nM of the irrelevant anti-digoxin mAb 1C10 showed no inhibitory activity of IL2 secretion in contrast to the same concentration of anti-CD4 13B8.2 mAb which blocked the IL2 production (95.7±0.7% inhibition). As compared with the irrelevant recombinant Fab 1C10 showing no inhibition, 200 nM of 13B8.2 Fab displayed 61.3±4.6% inhibitory activity of IL2 secretion. Taken together, these results indicate that, as already demonstrated for other anti-CD4 mAbs [103], the baculovirus-expressed Fab 13B8.2 is able to inhibit the antigen-presenting function, a biological property also demonstrated for the 13B8.2 parental mAb. [0049] In order to verify the ability of recombinant Fab to inhibit HIV-1 promoter activity, as the parental 13B8.2 mAb does, we measured the β-galactosidase reporter gene expression after infection of the indicator cell line HeLa P4 cultured for three days in the presence of products. As shown in FIG. 5(B), 7.8 nM of 1C10 mAb did not display any inhibitory activity in contrast to the same concentration of aprental 13B8.2 mAb which inhibited HIV promoter activation (60.3±5.0% inhibition). Culturing infected HeLa P4 cells with irrelevant baculovirus-expressed Fab 1C10 did not affect the β-galactosidase expression, whereas significant inhibition (61.2±4.5%) was found with 200 nM of the anti-CD4 recombinant Fab 13B8.2. These results indicate that the baculovirus-expressed Fab 13B8.2 showed anti-viral property, as already demonstrated for the parental anti-CD4 mAb 13B8.2 [85, 86]. [0050] We prepared a chimeric recombinant anti-CD4 Fab expressed in baculovirus that mimics the biological properties of the parental 13B8.2 antibody. Such a functional anti-CD4 antibody provides for use of the recombinant Fab in mammals. The chimeric mouse-human Fab 13B8.2 was able to recognize a CDR3-like region in the D1 domain of CD4, comprising Glu87 and Asp88 residues previously described by site-directed mutagenesis as involved in the 13B8.2 epitope [83, 104]. IL2 secretion of activated T cells upon antigen presentation can be inhibited by the chimeric Fab, indicating that the baculovirus-expressed recombinant molecule showed immunosuppressive property classically observed for anti-CD4 antibodies [103]. As previously reported for the mouse mAb 13B8.2 [85], the recombinant anti-CD4 Fab was able to prevent HIV-1 promoter activation. This activity was probably related through the inhibition of the ERK/MEK signaling pathway as already demonstrated for the 13B8.2 mAb [105]. Taken together, these results indicate that the Fab has retained a major part of the parental 13B8.2 mAb properties and can be used without the side-effects of a mouse mAb. This is especially beneficial in pharmaceutical compositions. [0051] The mAb 13B8.2 was shown to block gp120 binding to CD4, inhibit HIV-induced cell fusion and prevent viral production by infected cells [82]. Inhibition of viral gene transcription in HIV-cell culture and blockade of viral production from chronically-infected cells have been demonstrated following in vitro treatment with 13B8.2 antibody, these activities being obtained with HIV-1 and HIV-2 virus isolates [85]. In addition, the 13B8.2 mAb was able to elicit gp120-specific idiotypic antibody response in rabbits, thereby inhibiting syncitium formation [106]. These results led to experiments using mouse 13B8.2 antibody for HIB-1-infected patients [87-89]. Although these experiments led to clinical benefit for the patients, i.e., disappearance of circulating p24 together [87, 89] with negativation of the reverse transcriptase assay [87] or generation of serum antibodies to gp120 and HIV-1 neutralizing antibodies [89], adverse effects such as an anti-allotype or -isotype response to the foreign antibody [87, 89] or CD4 + clearance by the Fc portion of the antibody [87, 89] have also been documented. In sharp contrast, the chimeric Fab of this invention, showing antiviral activity like 13B8.2 mAb [83, 85, 86], is a valuable tool to overcome such problems. [0052] Some anti-CD4 antibodies have already been used in the treatment of various autoimmune diseases or allograft rejection [107-110]. Early clinical trials using murine anti-CD4 mAbs [111] have often been discouraging, with mild tolerance of the antibody preparation and a systematic human anti-mouse response. This latter side-effect leads to the clearing of the infused mAb and induction of anaphylactic responses [112]. One way to overcome these undesirable effects has been the generation of human mAb from human immunoglobulin transgenic mice [113]. Several strategies using DNA technology have also been described, such as primatization in which anti-CD4 variable regions (V-regions) from antibody generated in macaques are fused to human constant regions [114], humanization by grafting of murine anti-CD4 CDRs inside human antibodies [92], chimerization in which murine anti-oCD4 V-regions are co-expressed with human constant domains [91]. These re-designed recombinant anti-CD4 molecules demonstrated efficient immunosuppressive activity for treatment of autoimmune diseases or transplant rejection and were shown to be devoid of the adverse side-effects of mouse antibodies. In a similar manner, the engineered chimeric anti-CD4 Fab 13B8.2, which inhibits antigen presentation, is a potent immunosuppressive agent that can be used against autoimmune diseases or for allograft rejection. Furthermore, the Fab format could overcome prolonged CD4 + cell depletion, a negative effect often described following in vivo treatment with whole anti-CD4 antibody [115, 116]. This effect has been attributed to synergy between complement binding capacity and Fe receptor binding on phagocytic cells [114]. Since a Fab molecule lacks the second and third domains of the heavy chain constant region which bear complement and Fc binding abilities, the chimeric Fab fragment might be devoid of cell-depleting potential, as is also the case for F(ab)′ 2 fragments which block immune response to coadministered antigens and prevent the development of spontaneous autoimmune conditions [117]. Our anti-CD4 recombinant Fab probably acts as a pure receptor antagonist, either blocking CD4 receptor function or modulating the CD4 molecule on the T lymphocytes. [0053] The baculovirus/insect cell expression system is an interesting way to produce antibodies for therapeutic purposes [118] because of its capability for a high production level [119] and the absence of known intrinsic or secreted molecules toxic for man. This is in contrast with E. coli which can release endotoxins or plants which contain toxic or allergenic compounds [119]. In addition, the ability of insect cells to grow without serum avoids the presence of mammalian contaminants [119], leading to safe and secure antibody preparation. Furthermore, the development of baculovirus surface display [120-124] coupled with a non-lytic insect cell expression system [125] might increase the applicability of this alternative eukariotic source for the generation of human antibodies. [0054] The baculovirus/insect cell expression system allowed the production and purification of active recombinant Fab directed against the CDR3-like region of the D1 domain of CD4. This chimeric molecule retained the CD4 binding activity and the immunosuppressive properties of the parental mAb 13B8.2, thereby demonstrating its usefulness for pharmaceutical compositions. EXAMPLE 2 [0055] Cloning and Sequencing of 13B8.2 mAB V H and V L Genes [0056] The general procedures concerning the cloning and sequencing of 13B8.2 mAb variable regions have been described [46]. [0057] Peptide Synthesis on Cellulose Membranes [0058] 202 overlapping dodecapeptides frameshifted by one residue representing the V H and V L sequences of 13B8.2 mAb on a cellulose membrane were synthesized according to previously described protocols [37]. [0059] Assay for sCD4 Interaction with Cellulose-Bound Peptides [0060] The saturated membrane was incubated with a 20 nM solution of biotinylated-rhCD4 for 2 h at 37° C. Bound biotinylated-rhCD4 was detected by incubating the membrane for 1 h at 37° with a 1:3000 solution of alkaline phosphatase-conjugated streptavidin (Sigma, St. Louis, Mo., USA) and subsequent addition of 5-bromo-4-chloro-3-indolyl phosphate substrate. Inhibition of biotinylated-rhCD4 binding was performed as described above, except that biotinylated-rhCD4 (20 nM) was pre-incubated for 18 h at 4° C. with 13B8.2 mAb (6.25 μM). In all cases, the reactivity of the spots was evaluated by scanning the membrane and measuring the intensities of the spots with the NIH image 1.61 software [39]. [0061] Synthesis of Soluble Peptides [0062] The nine selected PDPs, named CB1 to CB9 (FIG. 6, right panel for sequences), a scrambled form of PDP CM9 (ScCM9: GSDQWNKMQYYP) [35], a scrambled form of the CD4-derived CDR3-like peptide (ScCDR3-like: KEEICEVEDQTY), and an unrelated peptide (Dig97c: FGDYYCLQYASS, derived from the CDR-L3 region of the anti-digoxin 1C10 mAb), with Lys-Cys residues added to both carboxyl- and amino-termini of all peptides, were synthesized by Fmoc solid-phase synthesis on an AMS422 robot (Abimed, Langelfeld, Germany), cyclized and purified as described previously [35]. Lys and Cys residues were added, respectively, to improve the solubility and permit cyclization of the peptides. The peptides showed homogeneity in high performance liquid chromatography at the expected monomeric molecular weight. Thereafter, the peptides were resuspended in deionized water, except for the scCDR3-like peptide which was suspended in a 10% acetonitrile solution and the CB8 PDP in a 20% acetonitrile solution. [0063] Baculovirus Expression of Recombinant His 6 -sCD4 [0064] The nucleotide sequence of soluble CD4 (D1-D4) was sorted by polymerase chain reaction from the pMV7-T4 plasmid by using the sense primer SCD4FB (5′-GAAGATCTATGAACCGGGGAGTCC), which matches codons 1 to 6, and the anti-sense primer SCD4RTB (5′-GAAGATCTTCAATGGTGATGGTGGTGGTGACCTAATGCGGCCATTGGCTGCACCGGG), which contains the reverse complement of codons 367 to 372 of CD4 and encodes the His 6 -tag and a BglII restriction site. Following sub-cloning into the pGEM-T vector (Promega, Madisoin, Wis., USA), the sCD4 sequence was verified by using the dideoxy termination method with the T7 sequencing kit (Pharmacia, Uppsala, Sweden). The BglII-linearized His 6 -sCD4 fragment was cloned into the p119L baculovirus transfer vector to allow the expression of His 6 -sCD4 under the P10 promoter. After transfection of Spodoptera frugiperda Sf9 cells (ATCC CRL 1711), recombinant baculoviruses were further purified by using a plaque assay and propagated in Sf9 cells [47,48]. Supernatant of Sf9 cells infected with the His 6 -sCD4 recombinant baculovirus in a spinner culture (10 6 cells/ml) were harvested 6 days post-infection and clarified by centrifugation at 1000×g for 5 min. [0065] Purification and Characterization of His 6 -sCD4 [0066] Purification of the His 6 -sCD4 product was carried out by using Ni-NTA agarose beads (Qiagen, Chatswroth, Calif., USA) according to the manufacturer's procedure with minor modifications. Briefly, the clarified baculovirus supernatant was dialyzed against washing buffer (50 mM NaH 2 PO 4 , 500 mM NaCl, 5 mM imidazole) for 24 h at 4° C. Ni-NTA agarose beads were then added to a final concentration of 5%, and the binding of His 6 -sCD4 was performed for 18 h at 4° C. Beads were washed with 8 volumes of washing buffer and His 6 -sCD4 was eluted as 1 ml fractions with 3 volumes of elution buffer (50 mM NaH 2 PO 4 , 500 mM NaCl, 300 mM imidazole). The Ni-NTA agarose beads were regenerated with 1 M imidazole. All purification fractions were checked for the presence of His 6 -sCD4 by enzyme-linked immunosorbent assay (ELISA) and Western blot using the anti-CD4 13B8.2 mAb as detection reagent. [0067] Binding Studies of PDPs to CD4 [0068] Three replicates corresponding to 10-fold serial dilutions of the nine cyclic PDPs (CB1-CB9) were coated overnight at 4° C. onto 96-well ELISA plates (Nunc. Paisley, UK) with an initial peptide concentration of 50 μM. Four washes in 160 mM PBS, pH 7.2, containing 0.1% Tween 20 (PBS-T) were performed before and after saturating the wells with 1% non-fat dry milk in PBT-T for 1 h at 37° C. Thereafter, 100 μl of 20 nM His 6 -sCD4 was added to each well. Following a 2 h incubation and four washes in PBS-T, bound His 6 -sCD4 was detected by addition of 100 μl of a 1:2000 solution of peroxidase-conjugated anti-His 6 mAb (Sigma) and subsequent addition of peroxidase substrate. Absorbance was measured at 490 nm. [0069] Binding Specificity of PDPs CB1 and CB8 to CD4 [0070] Inhibition of His 6 -sCD4 binding to PDPs was performed by an ELISA method with PDPs CB1 and CB8 coated at 12.5 and 2.5 μM, respectively, as capture reagent. A 20 nM solution of His 6 -sCD4 showing an absorbance at 490 nm of 1.0 was co-incubated with two-fold serial dilutions of 13B8.2 mAb. Three replicates were tested for each dilution with an initial mAb concentration of 3 μM. His 6 -sCD4 binding was evaluated as described above. [0071] Interleukin-2 (IL-2) Secretion Assay Following Antigen Presentation [0072] EBV-Lu antigen-presenting cells (10 6 cells/ml), overnight pulsed with the pep24 stimulator peptide (75 μM) from HIV gp120 [44], were co-cultured with pdb10f responder cells (4×10 5 cells/ml) in the presence or absence of inhibitor PDPs or mAbs for 24 h. Thereafter, 100 μl of supernatant was harvested and tested for IL-2 secretion using an ELISA commercial kit (Pharmingen, San Diego, Calif., USA). A positive control for IL-2 secretion was performed as described above except that activation of pdb10F cells was done using a murine anti-CD3 antibody at a concentration of 0.6 nM (Pharmingen) [49]. [0073] HIV-1 Promoter Activation Assay [0074] HeLa P4 indicator cells (8×10 4 cells/ml) were cultured in medium supplemented or not with 1000 TCID 50 of infectious HIV-1 Lai in the presence or absence of peptides or mAb for 3 days, harvested and lysed. The β-galactosidase activities were then determined as previously described [45] by measuring the absorbance at 410 nm. [0075] Characterization of Nine Peptides from 13B8.2 mAb Demonstrating CD4 Binding Ability [0076] The nucleotide sequences of VH and VL domains of 13B8.2 mAb were established according to the general procedure described by Chardès et al. [46] and made available from the EMBL database under the accession numbers AJ279001 and AJ27900, respectively. The complete amino acid sequences of both chains are given in FIG. 6 with somatic mutations indicated. Genetic analysis of these sequences showed that the V H region of 13B8.2 mAb resulted from the rearrangement of V H 2-DQ52-J H 3 genes and that the V L region resulted from a V κ 12/13-J κ 2 gene rearrangement. More precisely, computer-assisted comparison of these sequences showed that the V H and V L genes of 13B8.2 displayed significant homologies with Ox2 [50] and k2[51] germline genes, respectively (FIG. 6). It is worth noting that no significant homology was found between 13B8.2 mAb variable sequences and other anti-CD4 variable domains. [0077] 202 overlapping dodecapeptides frameshifted by one residue, corresponding to the deduced amino acid sequence of V H and V L from 13B8.2 mAb, were synthesized on a cellulose membrane by using the Spot method. The anti-CD4 immunoreactivity of these peptides was assessed by incubating the membrane with biotinylated-rhCD4. The results are quantitatively expressed in FIG. 7 (left panel) in which the reactivity of peptides that comprise at least one residue from the CDRs are boxed. Anti-CD4 reactivity was observed for peptides including amino acids from five of the six CDRs of 13B8.2 mAb (peptides 20, 22, 28-35; 46, 48-52, and 93-97 for CDR-H1, CDR-H2 and CDR-H3, respectively, and 22, 23, 29-34; 83-89 and 91 for CDR-L1 and CDR-L3, respectively). Anti-CD4 activity was also obtained for peptides containing residues from the framework, mainly flanking the CDRs (peptides 18, 36-38 and 66-71 for V H , and 35-38 and 57-61 for V L ) but the majority of peptides comprising only framework residues did not display any significant binding activity. This reactivity was drastically decreased when biotinylated-rhCD4 was pre-incubated with an excess of 13B8.2 parental mAb. Nine peptides (29, 30, 48, 52, 90 and 94 for V H and 22, 29 and 86 for V L ), named CB1 to CB9 (FIG. 2, right panel), were selected for further study in a soluble form. These peptides, except for 22 and 29 from CDR-L1, showed the highest anti-CD4 activity and comprised at least 50% of residues belonging to CDRs. Since the most reactive peptides derived from the CDR-L1 showed less than 50% of residues from the CDR (peptides 31 and 34), We selected two adjacent reactive peptides, namely, 22 and 29. Except for PDP CB4, that exclusively comprised amino acids from the CDR-H2, all selected PDPs comprised amino acids from both CDR and framework sequences. [0078] Soluble Cyclized Selected PDPs Demonstrate CD4 Binding Activity [0079] Peptides selected according to the Spot results were synthesized and N- to C-terminus cyclized through cysteine oxidation. Cyclization has already been demonstrated as a useful tool to improve antigen binding [36]. The ability of recombinant His 6 -sCD4 expressed in baculovirus to specifically bind cyclic PDPs was assessed by ELISA (FIG. 8). The selected PDPs, except CB3 from the CDR-H2, showed a dose-dependent CD4 binding activity. PDPs CB1 and CB2 derived from the 13B8.2 CDR-H1 region, and PDP CB8 derived from the 13B8.2 CDR-L1 region, displayed high binding activity in a 0.5-50 μM concentration range. The non-reactivity of irrelevant ScCDR3-like and ScCm9 peptides indicated that the addition of lysine and cysteine residues for solubilization and cyclization of peptides had no effect on CD4 binding. Since PDPs CB1 and CB2 only differ by one amino acid residue, we focused our attention on PDP CB1, derived from the CDR-H1, and PDP CB8, derived from the CDR-L1 of 13B8.2 mAb for further specificity studies. [0080] PDPs CB1 and CB8 Specifically Bind to CD4 on the same Region as that of Parental 13B8.2 mAb [0081] The ability of the parental mAb 13B8.2 to displace the binding of PDPs CB 1 and CB8 to His 6 -sCD4 was studied by using an ELISA inhibition assay. The absorbance of residual His 6 -sCD4 binding to PDPs was measured at 490 nm and expressed as percent inhibition of the binding (FIG. 9). We found that 13B8.2 mAb was able to displace the binding of His 6 -sCD4 (20 nM), in a dose-dependent manner, to both coated PDPs CB1 (12.5 μM) and CB8 (2.5 μM) with similar efficiencies. A 50% inhibition of binding PDPs CB1 and CB8 to CD4 was obtained for 13B8.2 mAb concentrations of 20 and 8 nM, respectively. No inhibition was found when using the IgG1 isotype-unrelated anti-digoxin mAb 1C10, demonstrating the specificity of the competition studies. [0082] Similar results were obtained in a symmetric experiment in which the binding of His 6 -sCD4 (20 nM) to 13B8.2 mAb (0.3 nM) was inhibited by various concentrations of PDPs CB1 and CB8. A 50% inhibition of binding of His 6 -sCD4 to 13B8.2 mAb wase obtained for concentrations of PDPs CB1 and CB8 up to 75 and 125 μM, respectively. Taken together, these data are consistent with the hypothesis that 13B8.2 mAb, CB1, and CB8 peptides recognized the same antigenic region on the CD4 molecule. [0083] PDP CB1 is able to Inhibit IL-2 Secretion Following Antigen Presentation [0084] The stimulation of pdb10f responder T cells by pep24-pulsed EBV-Lu APC leads to the lymphocyte secretion of IL2[43,44]. This T cell activation model is specific since no IL-2 secretion occurs when EBV-Lu antigen-presenting cells are pulsed with a non-stimulator pep23 antigen. We checked the viability of pdb10f responder cell line by activating cells with a murine anti-CD3 mAb which induced IL-2 secretion (data now shown). As shown in Table 1, the irrelevant anti-digoxin mAb 1C10 showed no inhibitory activity of IL2 secretion in contrast to the anti-CD4 13B8.2 mAb which blocked the IL2 production (99.6±0.2% inhibition). As compared to the irrelevant ScCM9 peptide showing no inhibition, PDP CB1 displayed inhibitory activity of IL2 secretion in a 125-250 μM concentration range. The biological activity of PDP CB2 was found to be very moderate since no activity was found at a concentration lower than 250 μM. [0085] The lack of activity for PDP CB8 was found to be consecutive to cell death, probably due to the presence of 20% acetonitrile in the buffer used to solubilize the peptide. The other selected PDPs demonstrated no or extremely low blocking of IL2 secretion. Taken together, these results indicate that, as already demonstrated for other anti-CD4 mAbs [52,53], the CDR-H1-derived PDP CB1 is able to inhibit the antigen-presenting function, a biological property also demonstrated for the 13B8.2 parental mAb. [0086] PDP CB1 Displays a Strong Capacity to Inhibit HIV-1 Lai LTR-Driven β-Galactosidase Reporter Gene Expression [0087] The parental mAb 13B8.2 has been previously demonstrated to be an inhibitor of viral particle production by cells infected with HIV-1 Lai , HIV-1 Eli , HIV-1 Sf2 , HIV-1 Ger and HIV-2 Rod strains [13,54]. In addition, viremia negativation has been observed for HIV-infected patients treated with 13B8.2 antibody, demonstrating its efficiency towards primary clinical isolates [31,32]. In order to assess the ability of selected 13B8.2 PDPs to inhibit HIV-1 promoter activity, we measured the β-galactosidase reporter gene expression after infection of the indicator cell line HeLa P4 cultured for 3 days in the presence of peptides. As shown in FIG. 10A, the 1C10 mAb did not display any inhibitory activity in contrast to the parental 13B8.2 mAb which inhibited HIV promoter activation. Culturing infected HeLa P4 cells with irrelevant Dig97c or ScCm9 peptides did not affect β-galactosidase expression, whereas a significant inhibition was found when the cells were cultured with a 50 μM solution of 13B8.2 PDPs CB1, CB2 and CB5. [0088] The lack of activity for PDP CB8 was found, in this assay, also to be consecutive to cell death caused by the presence of 20% acetonitrile in the buffer used to solubilize the peptide since no inhibition was observed with the PDP CB1 diluted in the same 20% acetonitrile buffer. In FIG. 10B, we demonstrated that the inhibitory effect of CB1 is dose-dependent, with an IC50 for CB1 of about 15 μM, whereas the IC50 of the parental mAb was found to be 5 nM. These results indicate that the CDR-H1-derived dodecapeptide CB1 has anti-viral activity, as already demonstrated for the parental anti-CD4 13B8.2 mAb. [0089] The CD4 molecule plays a key role both in the MHC class II-restricted immune response and the human immunodeficiency virus infection process by acting as a receptor either for the TcR-antigen engagement complex or for the envelope glycoprotein gp120 of HIV [7,9,55,56]. In these two cases, CD4 has been demonstrated to induce signal transduction leading to T cell activation [12,19,21,22]. Both of these mechanisms can be inhibited by treatment with anti-CD4 mAbs including murine 13B8.2 mAb [28-30]. Such inhibitory properties have lead to the use of 13B8.2 mAb in HIV-infected patients [31-33]. To avoid problems encountered when using mAbs in therapeutic approaches, such as immunogenicity and low tissue diffusion, we designed and synthesized PDPs from the 13B8.2 anti-CD4 mAb. [0090] We demonstrated that the CDR-H1-derived PDP CB1 displays significant and specific biological properties mimicking those of the parental anti-CD4 13B8.2 mAb. First, in an in vitro model of MHC class II-restricted immune response, we demonstrated that anti-CD4 PDP CB1, as well as parental mAb 13B8.2, inhibits IL2 secretion by activated T cells following antigen presentation. This inhibitory effect, classically observed for anti-CD4 mAbs [52,53], was dose-dependent. Since anti-CD4 mAbs have been described to prevent T cells from IL2-induced proliferation and B cell adhesion through inhibition of Ca 2+ and P21 ras signaling pathways [57,58], it remains to be assessed whether our anti-CD4 PDPs could interfere with such mechanisms. The effect of CB1 in an in vivo model of immune disorder remains to be investigated, as it was done for anti-CD4 CDR3-like-derived analogs in a murine experimental allergic encephalomyelitis model [59]. Second, we found that the PDP CB1 inhibited HIV-1 promoter activation, as 13B8.2 mAb does [29]. The mechanism by which 13B8.2 mAb exerts this anti-HIV property has been related to inhibition of signal transduction, involving the extracellular regulated kinase/mitogen-activated protein kinase kinase signaling pathway [13]. We also believe that CB1 acts by disrupting the same signal transduction machinery, thereby preventing HIV pro-virus transcription. [0091] We found that peptides CB1 and CB8 displayed specific anti-CD4 binding activity. A relatively high concentration of peptides is preferred to achieve efficient biological activity with regard to the efficient antibody dose. To explain this difference, we measured the binding of CD4 to PDP CB1 and observed a 50% decrease in binding when following pre-incubation of the peptide for 25 min at 37° in a buffer containing 10% fetal calf serum (data not shown). This finding strongly suggests that the high concentrations of CB1 which achieve a biological effect reflects degradation of the peptide in the culture medium. We believe that use of D-amino acids for peptide synthesis would improve their metabolic stability [60]. [0092] We believe that a longer sequence of PDP CB8 including hydrophilic flanking residues will improve the solubility of the peptide and avoid the use of organic solvent. This is of great interest because of a high sequence/position homology between this CDR-L1-derived PDP CB8 and a previously characterized CDR-L1-derived PDP, the CM9 peptide, derived from the anti-CD4 ST40 mAb that inhibits HIV transcription [35]. Comparison of alanine-scanning analysis of these two peptides indicated that similar residues located at the same positions, i.e. Tyr 32 , Trp 35 , Tyr 36 , Lys 39 , contribute to CD4 binding [36]. This may help us understand the structure-function relationship in these series of anti-CD4 mAb-derived bioactive molecules. [0093] The systematic exploration of the 13B8.2 mAb paratope has led us to the characterization of PDPs CB1 and CB8, displaying high anti-CD4 reactivity and including residues from the CDRs and from the framework flanking these CDRs. The role of residues outside the CDRs (i.e. Trp 36 and Arg 38 in the CB1 sequence, and Tyr 36 in the CB8 sequence) has already been described as being important in structuring the active CDR loops in the full mAb paratopes [61,62]. Moreover, Park et al. [63] demonstrated the relevant importance of adding aromatic residues to improve the efficiency of their CDR-H3-derived anti-HER2/neu peptide mimetics. The addition of aromatic residues has been found to be a valuable strategy for enhancing stability, folding, and avidity of peptidomimetics [25,64-66]. This could explain the high reactivity obtained for PDP CB1, in which the natural Trp 36 residue may have such function. We demonstrated differences, both in anti-CD4 binding activity and in biological properties, between PDPs CB1 and CB2, that are frameshifted by only one residue. Two key points may explain these differences. First, PDP CB2 contains the Pro 41 residue which may constrain the peptide in an unfavorable conformation. Second, in PDP CB2 the Leu 29 residue is absent. The Leu 29 residue is part of the Vernier zone [67], already described to stabilize Ag/Ab interactions. These two factors may contribute to twisting PDP CB2 into a less favorable conformation for CD4 binding, thereby explaining the decreased bio-logical properties of CB2. Taken together, these data confirm the capacity of the Spot method in defining antigen-specific peptides derived from a mAb paratope that present paratope-derived residues in an environment compatible for antigen binding. [0094] The CDR-3-like loop of domain 1 of CD4, and more precisely the negatively charged residues Glu 91 and Glu 92 , has been shown to play a role in activating T cell signal transduction [20,21]; Glu 91 and Glu 92 are also involved in the 13B8.2 paratope [16]. Inhibition studies demonstrated that PDP CB1 and 13B8.2 mAb specifically compete for CD4 binging on the same region of the molecule. Alanine scanning of the CB1 sequence showed that the main contributor residues are positively charged (i.e., His 35 and Arg 38 , unpublished data), thereby possibly interacting with its negatively charged epitope on the CD4 molecule. The CDR3-like loop from the D1 domain of CD4 has been reported to be involved in on of the two potential CD4 dimerization sites [20,21,68,69]. 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An isolated CDR-derived polypeptide from monoclonal antibody 13B8.2, a pharmaceutical composition including a pharmaceutically acceptable carrier and at least a peptide, and a method for treating a subject suffering from an autoimmune disorder, including administering to the subject a therapeutically effective amount of a pharmaceutical composition, a method for treating a subject suffering from a transplant rejection including administering to the subject a therapeutically effective amount of a pharmaceutical composition, a method for treating a subject suffering from an HIV immunodeficiency disorder including administering to the subject a therapeutically effective amount of a pharmaceutical composition and a method for treating a subject suffering from a tumoral disorder including administering to the subject a therapeutically effective amount of a pharmaceutical composition.

PRIORITY INFORMATION [0001] This application claims the benefit of U.S. Provisional Application No. 60/432,418 on Dec. 12, 2002. FIELD OF THE INVENTION [0002] The field of this invention relates to a method of cleaning a well bore with a tubular wiper and valve arrangement. BACKGROUND OF THE INVENTION [0003] During the process of drilling and completing a well it is often desirable to remove all solid materials from the mud system in the well bore as well as removal of cement, metal and other materials which may cling to the wall of the tubular or in the case of a deviated well be laying on the side or bottom of the partially horizontal tubular. In many cases it is also desirable to change out the mud system in the well bore to a completion fluid, which is free of solids. [0004] Currently this process is accomplished by running a tubular (commonly called a “work string”) to or near the bottom of the well. Then circulating fluid through or down this work string and into the annulus between the tubular and well bore. Circulation is accomplished by pumping fluid down the work string and back to the surface through the annulus between the work string and casing. [0005] To assist in these process mechanical devices such as casing scrapers and brushes are attached near the bottom of the work string to remove the solids that may cling to the casing such as cement, formation debris or metal particles. [0006] Circulation to remove the solids requires turbulent flow. In most if not all cases sufficient pump capacity is not available to accomplish the required flow rates. The flow area of the annulus is no less than 3 times and more often 5 to 10 times that of the work string. Therefore the flow rate required to maintain turbulent flow in the annulus is at least 3 times that required in the work string. By causing the solid laden fluid to flow to the surface through the work string the solids are more likely to be removed from the well due to the higher velocity fluid stream in the work string. This is particularly true in deviated wells where it is known that the mud system will “channel” and not cover the entire annular area. In these cases the solids remain in the well bore and can cause failure of packers, valves, etc. that are run in the well as a part of the completion process. These solids can also cause formation damage that prevents the well from producing at its maximum or prevents injection into the formation. [0007] It is therefore evident to those familiar with these processes that it is desirable to move the solids to the surface by forcing them into the highest velocity flow available this being the work string. [0008] The newest known device that represent this type of well bore clean out method is from Baker Oil Tools titled “The Well Bore Custodian” These devices are run and pulled from the well bore to remove the solids from the casing wall and place them in the mud system. Most devices require circulation to remove the solids; recognizing that circulation alone can not remove the solids, Bakers' device attempts to remove the solids by filtering them from the mud system. This device relies on the filtering system to retain the solids until the device is removed from the well. As seen in the prior art, filtering devices have been tried in the past and found not to remove all of the solids. [0009] In the past, as illustrated in several patents, there have been a variety of tools and techniques used to remove debris. U.S. Pat. No. 2,782,860 shows the use of reverse circulation into a pickup tube held by a packer inside a tubular. Several devices involve pulling vacuum on the tubular to suck fluid and debris into it. Some examples are U.S. Pat. Nos. 3,775,805; 4,630,691; 5,269,384; 5,318,128; 3,958,651 and 5,033,545 (fluid jet creates a vacuum). U.S. Pat. No. 5,402,850 uses a seal and crossover to force fluid with debris into the annulus around the tubular string for the trip to the surface. Other techniques involve reverse flow into the tubing string, such as: U.S. Pat. No. 4,944,348 and U.S. Pat. No. 5,069,286. Also of interest are U.S. Pat. Nos. 5,562,159 and 5,718,289. SUMMARY OF THE INVENTION [0010] Multiple embodiments of well bore clean out systems are disclosed. These embodiments remove the solids from the well bore annulus as soon as they are encountered and places them into the tubular being run in the well bore. This will place the solids into the inside of the work string where higher velocities will move the solids to the surface where they can be separated from the mud system. This is made practical by newly patented devices such as those disclosed in patents U.S. Pat. No. 6,390,190 and U.S. Pat. No. 6,415,862. [0011] The system consists of at least one circulator assembly having a port below a packer cup to divert fluid from the annulus into the work string as the work string is being lowered into the well bore. This system can consist of a circulator assembly for each casing size in the well being cleaned, in other words, multiple circulator devices on one work string with porting to control the flow of fluids. [0012] Valve assemblies are also be disclosed which selectively open and/or close to direct flow either into the tubular or around the packer cup. This valve assembly provides a path for fluid around the packer cup when the work string and circulator is removed from the well. [0013] A method comprises of directing the mud above any mechanical cleaning devices and through a port below the packer cup into the tubular immediately below the packer cup. [0014] A valve assembly is disclosed that selectively opens the very bottom of the work string to allow reverse circulation to the bottom of the work string to thoroughly clean the well bore prior to removing any one of the assemblies from the well bore. [0015] An arrangement of packer cups is disclosed that assures that annulus fluid between circulators in different casing strings will be directed into the work string. In addition, a process comprises removing solids from the fluid system and casing wall. BRIEF DESCRIPTION OF THE DRAWINGS [0016] [0016]FIG. 1 is a sectional view of a well showing the apparatus positioned in a well having a single casing. [0017] [0017]FIG. 2 is a sectional view of a well having a casing and liner of different sizes showing different sizes of the apparatus positioned in each of the casing string and liner. [0018] [0018]FIGS. 3 and 3A are a sectional view of a mechanically operated apparatus being run into a well showing the port opened and a cup seal to force the fluid in the annulus into the inside of the apparatus. This view also shows a plug in the lower end of the apparatus to force all fluid in the well below the apparatus into the inside of the apparatus. [0019] [0019]FIGS. 4 and 4A are a sectional view of the apparatus in FIG. 3 showing the port closed so that pressure may be applied to the inside of the apparatus to force the plug out of the apparatus. [0020] [0020]FIGS. 5 and 5A are a sectional view of the apparatus in FIG. 4 showing the port closed and a passage opened under the cup seal to allow communication of multiple annuli above and below the cup seal. This view also shows a plug in the lower end of the apparatus to force all fluid in the well below the apparatus into the inside of the apparatus. [0021] [0021]FIG. 6 is a partial sectional view showing detail of the upper latch shown in the apparatus in FIG. 3. [0022] [0022]FIG. 6 a is an external view of FIG. 6. [0023] [0023]FIGS. 7 and 7A are a sectional view of a hydraulically operated apparatus being run into a well showing the port opened and a cup seal to force the fluid in the annulus into the inside of the apparatus. For simplicity, this view also shows the plug in the lower end of the apparatus removed. [0024] [0024]FIGS. 8 and 8A are a sectional view of the apparatus in FIG. 6 showing the port closed and a passage opened under the cup seal to allow communication of the annulus' above and below the cup seal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0025] Referring to FIG. 1, an embodiment A is illustrated that mounts a seal 10 to the work string 12 . Seal 10 can be any one of a variety of styles but a downwardly oriented cup seal is preferred. Not shown in FIG. 1 is the top end of the work string 12 that is connected to a device described in U.S. Pat. Nos. 3,390,190 or 6,415,862 or another surface mounted device that can connect the top of the work string 12 to separation equipment so the debris can be removed prior to the fluid returning to the mud pit. While the seal 10 is advanced downhole, it cleans the debris from the inner wall 14 of the casing 16 . Fluid in the annular space 18 below seal 10 is forced into the work string 12 , through ports 20 . Any suspended debris or debris scraped from the inner wall 14 goes into the work string 12 as a result of advancement of seal 10 . Annulus 2 above seal 10 can have fluid added into it to compensate for the downhole movement of seal 10 and to prevent high pressure from forming across seal 10 , which could retard the further advance of the apparatus A. The displaced fluid and debris that gets into the work string 12 will be directed through a connection apparatus of the type described in U.S. Pat. Nos. 6,390,190 or 6,415,862 or another device into surface separation equipment of known design (not shown) so that the screened fluid can be returned to the mud pit for future use. [0026] Also shown are ports 30 and 31 , which can be selectively opened or closed with ports 20 or conversely closed or opened to allow circulation or reverse circulation around seal 10 at any time during the deployment of apparatus A. The importance and operation of these ports will be more fully described later. [0027] Not illustrated are mechanical devices such as brushes and casing scrapers which may be placed below apparatus A to facilitate removal of solids from the casing wall 14 [0028] [0028]FIG. 2 adds a second apparatus A′ to the assembly shown in FIG. 1 for deployment in wells that have more than one casing size. Illustrated is apparatus A being deployed into casing 16 on work string 12 while apparatus A′ is deployed into liner 16 ′ on work string 12 ′. The transition from casing 16 to liner 16 ′ is shown by use of a seal and anchor system 3 which is often a liner hanger. [0029] Apparatus A will capture fluid and solids in annulus 18 while apparatus A′ will capture fluid and solids in annulus 18 ′. [0030] It is understood by those familiar with the art that apparatus A will be attached to a work string 12 which will be a length to position apparatus A near the liner hanger 3 , while the length of the work string 12 ′ will be sufficient to place apparatus A′ near the depth of the liner 16 ′. [0031] Also shown are ports 30 , 30 ′, 31 and 31 ′, which can be selectively opened or closed with ports 20 and 20 ′ or conversely closed or opened to allow circulation or reverse circulation around seals 10 and 10 ′ at any time during the deployment of apparatus A and A′. The importance and operation of these ports will be more fully described later. [0032] Again not illustrated are mechanical devices such as brushes and casing scrapers may be used below apparatus A and A′ to facilitate removal of solids from the casing walls 14 and 14 ′. [0033] [0033]FIGS. 3 and 3A show one of the preferred embodiments being run into the well casing 16 . The top sub 32 of the apparatus is threaded to the work string 12 . The top sub 32 is threaded to a mandrel 33 , which runs through the apparatus and terminates in a threaded connection to the bottom sub 41 . The top sub 32 and bottom sub 41 are sealed at the mandrel 33 connection with seals 42 and 45 respectively. [0034] A sleeve 11 is threaded to sleeve 35 . These sleeves have mounted on their exterior, cup seals 10 and 22 , which are supported by thimbles 10 B and 22 B. Though both cup seals, in FIG. 2, are shown facing downward it is apparent either of these seals can be positioned so that at lease one is facing upward. This can be important if circulation around the exterior of the seals is not wanted or if the fluid pressure in the annulus above the seals is higher than the pressure of fluid below the seals. [0035] These cup seals 10 and 22 are held firmly to the sleeves 11 and 35 by use of the threaded connection 54 between sleeves 11 and 35 so that rotation of mandrel 33 will not rotate sleeve 11 or 35 . The cup seals 10 and 22 are also separated by use of a cup sleeve 10 A. [0036] Sleeves 11 and 35 are held in an upward position and prevented from rotating by frictional forces between the cups 10 and 22 and the casing wall 14 . As the work string 12 is lowered the mandrel 33 will be urged downward with respect to the cups 10 and 22 until the sleeve 35 shoulders on the lower end 56 of the top sub 32 . [0037] Should it be anticipated that fluids of a higher pressure may be above the upper cup (one of the cup seals will then be facing upward), the sleeves 11 and 35 may be held in this upward position by threaded fingers 58 on collet 15 (FIG. 6) which is mounded to the mandrel 33 and has threaded fingers 58 (FIG. 6A) engaged into the internal mating threads 15 B (FIG. 6). Should there not be fluids of a higher pressure in the upper annulus there is no need to use the collet 15 . [0038] It is apparent to those familiar with the art that several apparatus may be run into a well on the same work string as indicated in FIG. 2. Each apparatus would have the same or similar porting arrangement as illustrated in FIGS. 3, 3A. [0039] As the apparatus is being run into the casing 16 fluid and solids below the seal 22 flow into ports 23 of the sleeve 35 and into ports 25 in the mandrel 33 then to the interior of the mandrel 18 where they flow to the surface where they flow directly to the mud system or separator and filtering equipment (not shown). Seal 42 located on the mandrel 33 isolates ports 19 and 17 . If this is the lowest apparatus in the work string as shown by apparatus A′ in FIG. 1, fluid is prevented from entering the lower end of the apparatus by plug 29 which is sealed to the interior of the mandrel 33 at seal 27 and is held in position by shear screws 37 mounted between the plug 29 and mandrel 33 . Plug 29 assures that all flow is through the ports 23 and 25 to maintain the highest velocity possible in annulus 34 . This will prevent solids from collecting and plugging the annulus 34 . This can be important where a casing scraper and or brushes (not shown) are used below the apparatus. The higher flow will help keep the solids moving through and around this equipment. Should this not be the lowest apparatus in the work string, plug 29 would not be used since flow from the lower apparatus' must move through the work string and all apparatus above and plug 29 would prevent this. [0040] A collet 40 is also shown at the lower end of the mandrel 33 the purpose of which will be explained later. [0041] Other devices such as scrapers, brushes, magnets, filters, plug catchers, work string, etc can be attached below the apparatus at threaded connection 49 . [0042] Referring now to FIGS. 4 and 4A, the apparatus is now shown as it would reach its lower most position in the well bore. At this time it would be desirable to reverse circulate the fluid that is in the work string to the surface since this fluid would contain solids swept from the well as the apparatus is deployed. Reverse circulation defined as moving fluid down the annulus 9 and up the inside of the tubular 18 as shown in FIGS. 5 and 5A. [0043] To reverse circulate it is necessary to close the ports 23 and 25 and open port 17 . This is accomplished by picking up on the work string 12 at the surface so that the mandrel 33 moves upward relative to sleeves 11 and 35 . In this position seal 37 will isolate ports 25 from 23 closing them and port 17 moves below seal 42 thereby opening port 17 . This will open an annular space 50 located between sleeves 11 and 35 and mandrel 33 forming a flow path between the upper annulus 9 and the lower annulus 34 to allow fluid above the apparatus to flow below the apparatus freely. [0044] Should the latch 15 be used it would be necessary to rotate the work string 12 as it was being raised to unscrew latch 15 from the mating threads 16 (FIG. 6) in sleeve 11 to allow the mandrel 33 to move upward relative to sleeves 11 and 35 . The same is true for latch 15 ′ except that the work string is rotated as it is being lowered to unscrew latch 15 ′ from mating threads 16 ′ (FIGS. 4 and 4A) in sleeve 35 . [0045] It is apparent that latches 15 and 15 ′ are not necessary for operation of the apparatus but serve the purpose of locking the apparatus in one of its two positions. [0046] When the mandrel 33 moves upward until the bottom sub 41 contacts sleeve 35 latch 15 ′ also engages mating latch threads 16 ′ at the lower end of sleeve 35 . This will hold sleeve 35 so that the tool remains in the reversing position. It is understood that the tool can be shifted back to the previous position by lowering the work string 12 while rotating to disengage the latch 15 ′ from its mating threads 16 ′. This will close port 17 and open ports 23 and 25 and engage latch 15 with mating threads 16 as shown in FIG. 6. [0047] To provide a flow path through the apparatus with ports 23 and 25 closed it is necessary to remove plug 29 . Pressure can now be applied to the interior of the work string 12 . This pressure will apply a force to plug 29 shearing screws 37 thereby releasing plug 29 from mandrel 33 and forcing plug 29 to the bottom of the work well or into a plug catcher sub located at the end of the tool assembly mounted below the apparatus, thus opening the work string. [0048] Referring now to FIGS. 5 and 5A, the apparatus is now shown in the reverse circulating position. Fluid can now be pumped into annulus 46 (at the surface) through port 17 , through the annular area 50 between mandrel 33 and sleeves 11 and 35 , out port 19 through annulus 34 then into the interior of the tool string 18 back to the surface. Reverse circulating will completely flush all fluid from the well bore replacing it with fluid that is pumped into the annulus at the surface. Again it is understood that there can be other assemblies below the apparatus. [0049] The arrangement of the sleeves 11 and 35 along with the friction of the cup seals 10 and 22 with the casing 16 provides a method of shifting the tool from the run in position to the reversing position at will. [0050] In addition the use of the latches 15 and 15 ′ with mating threads 16 and 16 ′ in sleeves 11 and 35 provides a method of not only shifting from one position to the other but locking the apparatus in either of the positions at will. [0051] Referring again to FIG. 2, should this be the upper assembly A in a tool string such that the fluid moving through the annulus 9 , 9 A and 28 will progress to the bottom assembly A′ then into the interior of the work string 12 . [0052] Referring now to FIGS. 7 and 7A, another embodiment is shown with a top sub 51 attached to the work string 12 . Inside the top sub 51 is a sleeve 52 sealed in the top sub 51 by seals 53 and 54 . A shifting sleeve 55 is located inside the sleeve 52 and is sealed in the sleeve 52 by seals 56 and 57 . The shifting sleeve 55 is also secured to the sleeve 52 and by shear screws 77 . Annulus pressure is vented through port 60 to an annular space 61 between top sub 51 and sleeve 52 , this pressure is then vented to the annular space 63 through port 62 where it operates on surface 59 of shifting sleeve 55 . [0053] This upper portion of the apparatus forms a hydraulic system with pressure inside the work string 12 operating on the upper portion of the shifting sleeve 55 at surface 58 and pressure in the annulus 9 working on the lower side of the shifting sleeve at surface 59 . [0054] Top sub 51 is attached to mandrel 64 . A number of cup seals 65 , 66 , and 67 are mounted on mandrel 64 and supported by thimbles 68 , 69 and 70 and held in place by cup spacers 71 and 72 while being secured to the mandrel by cup sleeve 73 . The cup seals, thimbles, cup spacers and cup sleeve components are secured by the bottom sub 74 , which is connected to the lower end of the mandrel 51 . [0055] If this is the lower apparatus such as A′ in FIG. 2 a plug 29 can be secured to the bottom sub 74 by shear screws 37 . Seal 27 also seals the plug 29 inside the bottom sub 74 . [0056] Other devices such as scrapers, brushes, magnets, filters plug catcher subs etc can be attached below the apparatus at threaded connection 49 . [0057] As indicated by arrows 28 , as this apparatus is lowered into the casing 16 by the work string 12 solids adhering to the casing wall 14 and fluids below the cup seals are directed into the work string 12 through ports 75 and 76 located in the cup sleeve 73 and mandrel 64 . Fluid is prevented from entering annular space 78 located between mandrel 64 and shifting sleeve 55 by seals 79 . Thus fluid is directed through the work string 12 to the surface where it can flow to the mud or filter system. [0058] After reaching the desired depth, application of surface pressure to the interior of the work string 12 will first shear screws 27 forcing plug 29 out the bottom of the assembly to the bottom of the well or into a plug catcher sub (not shown) located at the end of all devices below the lowermost apparatus in the work string (this apparatus), secondly this pressure will shear screws 77 allowing shifting sleeve 55 to move downward until it contacts bottom sub 74 . As this movement occurs seals 79 are moved below port 76 opening ports 75 and 76 to the annular space 78 between the mandrel 64 and shifting sleeve 55 thereby opening a path through port 80 to the annulus above the upper cup seal 65 . Prior to the shifting sleeve 55 contacting the bottom sub 74 surface 83 of the shifting sleeve will open “C” ring 84 . When shifting sleeve 55 contacts bottom sub 74 “C” ring 84 will snap into grove 82 of shifting sleeve 55 . This “C” ring 84 will hold shifting sleeve in this position. With this arrangement the shifting sleeve once shifted cannot be returned to its original position. [0059] Now referring to FIGS. 8 and 8A, as shown by arrows 81 reverse circulation can now occur by pumping fluid into the annulus between the casing 16 and work string 12 at the surface. This fluid will then be directed through ports 80 , annular spaces 78 and ports 75 and 76 of all such devices in the well to the lower most end of all devices where it will enter the interior of the work string 12 to be directed to the surface and back to the mud or filter system. [0060] The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention.

Several well bore clean-out apparatus' are disclosed that provides a method of cleaning a well bore while the apparatus' are being deployed into a well forcing well bore fluid into a work string and for moving solids to the surface. A method of cleaning multiple diameters of well casings is also disclosed. A method of circulating or reverse circulating the well at anytime during the deployment of the apparatus' is disclosed.

BACKGROUND OF THE INVENTION The present invention relates to the field of demagnetizing circuits, and in particular to a demagnetizing circuit for demagnetizing color picture tubes. Color picture tubes must be demagnetized in order to obtain sufficient color purity. For this reason, a demagnetizing coil is used through which a fading high-amplitude alternating current is sent when the equipment is turned on. However, the leakage current flowing through the demagnetizing coil during continuous operation should be as low as possible in order to reduce power dissipation. In conventional demagnetizing circuits, a positive temperature coefficient (PTC) thermistor in series with the demagnetizing coil is employed for obtaining the decreasing amplitude in the alternating current. The PTC thermistor is a resistor with a resistance that is a function of temperature, wherein the resistance increases as the temperature increases. The resistance of the PTC thermistor is thus very low when the equipment is turned on, that is, when it is cold, but it is substantially higher when it is warmed up in the operating mode. A problem with a PTC thermistor is that it suffers from the disadvantage that during continuous operation of the equipment, leakage current flowing through the demagnetizing coil and the PTC thermistor causes continuous power dissipation of approximately 2 W. This is particularly troubling in standby mode operation because the power consumption should be as low as possible in that mode of operation. Therefore, in expensive television sets the demagnetizing current, (i.e., the current flowing through the demagnetizing coil and the PTC thermistor) is turned off during continuous operation using an additional circuit (e.g., that includes a triac or optical coupling device). Therefore, there is a need for a demagnetizing circuit in which the desired current flow can be achieved with a reduced complexity control circuit and without substantial power dissipation occurring during continuous operation. SUMMARY OF THE INVENTION Briefly, according to an aspect of the present invention, a demagnetizing circuit for controlling a demagnetizing current applied to a demagnetizing coil includes at least two transistors that are controlled by at least one capacitive voltage divider. A rectified alternating voltage is applied to the capacitive voltage divider, which applies control signals to the transistors to control the demagnetizing current supplied to the demagnetizing coil. The demagnetizing circuit uses MOS or bipolar transistors rather than a PTC thermistor. Thus, with modest complexity in terms of the control, not only can a demagnetizing current with fading amplitude be produced, but the demagnetizing current returns to zero. As a result, after the demagnetizing no power dissipation occurs, which is particularly advantageous when the equipment is in standby mode. The transistors are controlled via a capacitive circuit that may include a single capacitive voltage divider, or at least two separate capacitive voltage dividers. Ideally, the inverse diode generally present in MOS transistors is also used. When using bipolar transistors that are not equipped with such inverse diodes, discrete diodes must be provided. In accordance with one exemplary embodiment of the present invention, the complexity of the control can be further reduced when the source and gate terminals for the two MOS transistors are connected to one another so that the demagnetizing circuit can be operated with just one capacitive voltage divider. In another aspect of the present invention, a demagnetizing circuit may retroactively actuate or activate the demagnetizing even after the equipment has been turned on, so that demagnetizing can also be performed during continuous operation of the equipment. This is particularly desirable when the equipment remains powered up for an extended period and is merely switched to standby outside of operating times. In this embodiment, an additional transistor is used (e.g., a small-signal transistor) and a corresponding voltage must be applied to this additional transistor to switch this transistor to the conducting state to initiate the demagnetizing. For instance, this can occur with a voltage that is low in the equipment standby mode and is high in the operating mode. The invention is particularly suitable for demagnetizing color picture tubes in television equipment. However, the invention is not restricted to this field of application; rather, it can be used in general whenever demagnetizing is to be performed using a demagnetizing coil. These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of preferred embodiments thereof, as illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic illustration of a demagnetizing circuit in accordance with a first exemplary embodiment of the present invention; FIG. 2 illustrates a plot of various voltage potentials and the demagnetizing current, both as a function of time, for the circuit illustrated in FIG. 1; FIG. 3 is a schematic illustration of a demagnetizing circuit in accordance with a second exemplary embodiment of the present invention; FIG. 4 is a schematic illustration of a demagnetizing circuit in accordance with a third exemplary embodiment of the present invention; and FIG. 5 is a schematic illustration of a demagnetizing circuit in accordance with a fourth exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a schematic illustration of a demagnetizing circuit that includes two MOS transistors for controlling demagnetizing current. The demagnetizing circuit includes two terminals AC 1 and AC 2 for applying an alternating voltage. Interposed between the two terminals AC 1 and AC 2 is a series connection comprising a first MOS transistor T 1 , two resistors R 3 and R 4 , and a second MOS transistor T 2 . The resistor R 3 limits the current, while the resistor R 4 corresponds to the ohmic equivalent resistance of a demagnetizing coil provided for demagnetizing. The drain terminals of the two transistors T 1 and T 2 are labeled D in FIG. 1, the source terminals are labeled S, and the gate terminals are labeled G. The two transistors T 1 and T 2 are each controlled via a capacitive voltage divider C 1 , C 2 , and C 3 , C 4 , respectively. The capacitors C 2 and C 4 are each connected to a control terminal ST, while the capacitors C 1 and C 3 connect the gate terminals G and the source terminals S of the transistors T 1 and T 2 . Clipper diodes D 1 and D 2 and discharge resistors R 1 and R 2 are connected parallel to capacitors C 1 and C 3 , respectively. Connected to the control terminal ST is the output of a bridge rectifier BR, the inputs of which are connected to the two terminals AC 1 and AC 2 . The bridge rectifier BR ensures that only positive half-waves are applied to the control terminal ST. Also connected to the control terminal ST is an electrolyte capacitor C 5 , the other end of which is connected to a ground. This electrolyte capacitor C 5 smoothes the voltage rectified by the bridge rectifier BR. Both the bridge rectifier BR and the electrolyte capacitor C 5 are components of a power supply unit that is to be connected to the demagnetizing circuit, as illustrated in FIG. 1 . The function of the demagnetizing circuit illustrated in FIG. 1 is explained in the following referring to FIG. 2 for the terminal AC 1 and transistor T 1 . FIG. 2 illustrates a plot of the demagnetizing current I 1 flowing through the demagnetizing coil R 4 and the voltage potentials V 1 and V 3 with respect to the half-waves applied to terminal AC 1 shown in FIG. 1 . When the power supply is on, the electrolyte capacitor C 5 is charged to the peak value of the supply voltage. During the next zero crossing of the supply voltage, the transistor T 1 is first conductive, since the gate terminal G of the transistor T 1 is positively biased relative to the source terminal S by the capacitive voltage dividers C 1 and C 2 located between the source terminal S of the transistor T 1 and the positive pole of the electrolytic capacitor C 5 . The gate/source voltage Vgs of the transistor T 1 is Vgs=V 3 *C 2 /(C 1 +C 2 ) (if the effect of the clipper diode D 1 is ignored). The clipper diode D 1 protects against exceeding the permissible gate/source voltage and ensures that the transient characteristics remain constant regardless of the height of the current supply voltage, whereby the amplitude of the demagnetizing current is reduced from one half-wave to the other. The values of the capacitors C 1 and C 2 should be such that the transistor T 1 can be fully turned on even at the smallest supply voltage at which the equipment can run. If the voltage applied to terminal AC 1 rises to its peak value during a half wave, the gate/source voltage of the transistor T 1 decreases since the voltage drops via the capacitive voltage dividers C 1 , C 2 . During the next maximum power, the voltage on the terminal AC 1 reaches the value of the voltage potential V 3 on the electrolyte capacitor C 5 , since V 3 equals the peak value of the voltage applied to terminal AC 1 . In contrast, the voltage potential V 1 does not quite reach the peak value, since the transistor T 1 begins to block shortly before the peak value is achieved. The voltage V 1 stabilizes at a value at which the transistor T 1 just remains conductive. The demagnetizing current I 1 flows in the forward direction through the current-conducting path of the transistor T 1 and over the resistors R 3 and R 4 , while the demagnetizing current flows in the reverse direction through the transistor T 2 (through the integrated reverse-conducting inverse diode). Once the peak value of the supply voltage is exceeded, the voltage applied to the terminal AC decreases again. Initially the voltage V 1 largely retains its value, and not until the voltage applied to the terminal AC 1 is less than the voltage V 1 does the transistor T 1 become completely conductive again and the voltage V 1 drops with the voltage applied to the terminal AC 1 . The process repeats itself with the next half wave, whereby in this case the process plays out with respect to the voltage applied to the terminal AC 2 in the lower area of the circuit (i.e., in the components T 2 , C 3 and C 4 , D 2 , and R 2 ). The voltage applied to the terminal AC 1 remains at zero, while the voltage applied to the terminal AC 2 changes in accordance with a sinusoidal half wave. These processes repeat themselves during the subsequent half waves, whereby however the capacitors C 1 and C 3 are gradually discharged through the resistors R 1 and R 2 . The voltages V 1 and V 2 therefore increase less and less, so the demagnetizing current I 1 flowing through the resistors R 3 and R 4 gradually decreases. In particular the voltages V 1 and V 2 and the demagnetizing current I 1 decrease exponentially, as shown in FIG. 2 (only V 1 is illustrated in FIG. 2 ), whereby the period T of the demagnetizing current I 1 is 20 ms at 50 Hz supply voltage. In this manner, the desired course for the demagnetizing current I 1 as described at the beginning is obtained using the demagnetizing circuit illustrated in FIG. 1 . FIG. 3 illustrates a simplified exemplary embodiment of the present invention. The resistors in the electric circuit (i.e., the current-limiting resistor R 3 and the ohmic resistance of the demagnetizing coil) are divided equally on the upper and lower parts of the circuit (R 3 =R 4 ). The source and gate terminals of the two transistors T 1 and T 2 are connected to one another. A common capacitive voltage divider C 1 , C 2 is provided for the two transistors T 1 and T 2 (with clipper diode D 1 connected parallel to the capacitor C 1 and with a parallel-connected discharge resistor R 1 ), so that the complexity of the control circuit is half that of the exemplary embodiment illustrated in FIG. 1 . FIG. 4 illustrates an exemplary embodiment equivalent to the exemplary embodiment illustrated in FIG. 1, wherein bipolar transistors are used rather than MOS transistors. If the bipolar transistors do not already contain reverse-conducting inverse diodes like the MOS transistors, these must be additionally provided. Therefore, the embodiment illustrated in FIG. 4 includes additional diodes D 3 and D 4 associated with the bipolar transistors T 1 and T 2 , respectively. Since bipolar transistors by nature have a limit in the base voltage, in contrast to FIG. 1 and FIG. 2 the limiting diodes D 1 and D 2 can be omitted, at least in a narrow region of the supply voltage. The additional resistors R 5 and R 6 included in the embodiment illustrated in FIG. 4 act as voltage dividers for the base voltage of the transistors T 1 and T 2 . FIG. 5 illustrates a demagnetizing circuit that makes it possible to retroactively demagnetize, even after the supply voltage has been turned on. Thus, with this circuit it is possible to demagnetize even when the equipment is operating. In the exemplary embodiment illustrated in FIG. 5, current-limiting resistors R 31 and R 32 are divided equally on the upper and lower part of the circuit. The gate terminals for the two transistors T 1 and T 2 are connected to one another as in FIG. 3 . The electric circuit for the demagnetizing current I 1 runs in a corresponding half wave from the first supply voltage terminal AC 1 via the first current-limiting resistor R 31 , the first transistor T 1 , the demagnetizing coil and its ohmic resistor R 4 , the second transistor T 2 , and the second current-limiting resistor R 32 to the second supply voltage terminal AC 2 . The current I 1 flows in the reverse direction in the subsequent half wave. Referring still to FIG. 5, the control member that ensures the exponential damping of the demagnetizing current I 1 includes capacitor C 2 , discharge resistor R 1 , and clipper diode D 1 . In this embodiment, the capacitor C 1 is not required since the gate/source capacitors of the two transistors T 1 and T 2 are formed by the parasitic input capacitors of these transistors. For reasons of clarity, neither the bridge rectifier BR nor the electrolyte capacitor C 5 are illustrated in FIG. 5 . In this exemplary embodiment, terminal K 1 acts as control terminal ST; the power supply is to be connected thereto with the connection point between the bridge rectifier BR and the electrolyte capacitor C 5 . In contrast to the preceding exemplary embodiments, the capacitor C 2 is not connected directly to the electrolyte capacitor C 5 , but rather via an additional resistor R 7 . The connection point for the resistor R 7 to the capacitor C 2 is connected to a ground via a series connection out of another capacitor C 6 and the collector-emitter segment of another transistor T 3 . The transistor T 3 is a small-signal transistor that must, however, be voltage-stable up to approximately 300 V. Connected parallel to the capacitor C 6 is another discharge resistor R 9 , and resistor R 8 is interposed between the connection point of the resistors R 7 , R 9 and the ground. The demagnetizing circuit illustrated in FIG. 5 functions as follows. In steady-state after the first demagnetizing (i.e., after the supply voltage has been turned on) the gate terminals G that are connected to one another and that are from the two MOS field effect transistors T 1 and T 2 discharge to the source potential so that the transistors T 1 and T 2 block and no more demagnetizing current I 1 flows. The collector of the transistor T 3 applies a voltage that is somewhat lower than the high voltage on the control terminal (i.e., on the terminal K 1 ). The voltage is lowered by the voltage dividers formed from the resistors R 7 and R 8 and this ensures that the permissible collector voltage of the transistor T 3 is not exceeded. If at some later time additional demagnetizing must be performed, the transistor T 3 is switched to the conducting state by applying a suitable voltage to the base terminal K 2 . Thus, in the embodiment of the transistor T 3 illustrated in FIG. 5 wherein T 3 is configured as an npn-transistor, a positive voltage must be applied to the terminal. This can occur, for example, by a voltage that is too low in the standby mode and is too high in the operating mode. A switched mode power supply control component such as TDA 16847 is particularly suitable for producing this voltage, since it has an output for power measurement at which a power-dependent voltage can be produced by simple wiring, but not a frequency or supply voltage-dependent voltage. By turning on the transistor T 3 , its collector is pulled to the ground, whereby the resulting negative voltage jump is transmitted via the capacitor C 6 so the voltage potential on the connection point of the capacitors C 2 and C 6 also drops almost to the ground potential (since the capacitors C 2 and C 6 are selected with C 2 <<C 6 , the voltage is only slightly capacitively divided). However, the voltage jump is also transmitted via the capacitor C 2 to the gate terminals G of the two transistors T 1 and T 2 . The gate terminals are held at ground potential by the diode D 1 . The capacitor C 6 is charged relatively rapidly via the resistor R 7 so that the voltage on the connection point of the capacitors C 2 and C 6 increases. This increase in voltage is transmitted by the capacitive voltage divider formed by the capacitor C 2 and the parasitic gate capacitors of the transistors T 1 and T 2 , to the gate terminals G of the two transistors. The limiting Zener diode D 1 prevents the permissible gate voltage from being exceeded. The transistors T 1 and T 2 are now conductive and a demagnetizing process is initiated as described above. The control circuit is re-set in preparation for another demagnetizing by turning the transistor T 3 off again. The charged capacitor C 6 is then gradually discharged through the resistance R 9 . Once the capacitor C 6 is discharged, the circuit is again ready for a new demagnetizing process. Although the present invention has been shown and described with respect to several preferred embodiments thereof, various changes, omissions and additions to the form and detail thereof, may be made therein, without departing from the spirit and scope of the invention.

For achieving a desired course in the demagnetizing circuit (I 1 ) and power dissipation that is as low as possible during continuous operation of a color television set, a demagnetizing circuit for controlling the demagnetizing current (I 1 ) includes two transistors (T 1 , T 2 ) that are controlled via a common or via two separate capacitive voltage dividers (C 1 -C 4 ). A rectified alternating voltage is applied to the capacitive voltage dividers (C 1 -C 4 ). The demagnetizing current (I 1 ) controlled by the transistors (T 1 , T 2 ) is supplied to a demagnetizing coil (R 4 ).

FIELD OF THE INVENTION Embodiments of the present invention relate generally to the field of illumination systems, and, more specifically, to systems and methods for embedding data into the light output of such illumination systems. BACKGROUND OF THE INVENTION Visible light communications refer to communicating data via the light output produced by lighting sources. Such communications is a promising way of enabling localized wireless data exchange in the future because a wide unlicensed frequency band is available for this and because light emitting diodes (LEDs) used to illuminate a room or a space can be applied to provide the communications. Possibly every lighting source of the future could become a communications source. One visible light communications technique is based on embedding data into the light output of an illumination device by modulating the light output of the illumination device in response to a data signal (such light output is sometimes referred to as “coded light” and abbreviated as “CL”). Preferably, the light output is modulated at a high frequency and/or using a special modulation scheme so that the modulation is invisible to human beings. For the realization of visible light communication systems of this kind, illumination systems usually employ dedicated driver electronics to allow superimposing a data signal onto the LED driving signal. FIG. 1 is a schematic illustration of such an illumination system 100 . As shown, the illumination system 100 includes a dedicated driver circuit 110 and a LED 120 , and is configured to generate a light output 125 according to light settings. The dedicated driver circuit 110 includes a drive signal generator 112 and a driver controller 114 . The illumination system 100 is configured to operate as follows. As shown in FIG. 1 , the light settings for the illumination system 100 are provided to the drive signal generator 112 . The light settings indicate what the average light output 125 should be in terms, for example, of light power, e.g. defined in lumen, and color. The drive signal generator 112 translates the light settings into a drive signal (e.g., a drive current) for the LED 120 and provides the drive signal to the driver controller 114 . The driver controller 114 is further configured to receive a signal 135 from a data source 130 . The signal 135 includes data bits to be embedded into the light output 125 of the LED 120 . The driver controller 114 is configured to modulate the drive signal to be applied to the LED 120 in response to the signal 135 in order to embed the data bits of the signal 135 into the light output 125 . Various techniques how the drive signal could be modulated in order to embed data into the light output of a light source are known to people skilled in the art (pulse width modulation, amplitude modulation, etc) and, therefore, are not described in further detail. One problem with such an approach is that modifying a conventional LED driver to function as the dedicated driver circuit 110 described above is complicated and costly to implement. Therefore, what is needed in the art is a technique for embedding data into a light output of a LED that does not require modulating the drive signal applied to the LED. SUMMARY OF THE INVENTION It is an object of the invention to provide a system and a method suitable for embedding data into the light output of a LED without modulating the drive signal provided to the LED. According to one aspect of the invention, an illumination device for embedding one or more data symbols of a data signal into a luminance output of the illumination device is disclosed. The illumination device includes a LED comprising at least a first segment and a second segment. The first segment and the second segment have a common electrode and are individually controllable. The LED is configured to generate the luminance output in response to a drive signal. The illumination device further includes a controller configured for switching the second segment on or off in response to the data signal to embed the one or more data symbols of the data signal. As used herein, the phrase “switch off a segment” [of a LED] refers to disrupting the drive signal provided to the segment. Similarly, the phrase “switch on a segment” [of a LED] refers to providing the drive signal to the segment. When a segment is switched off it does not generate light. When a segment is switched on, it generates light. The luminance output of the LED is a composition of the luminance outputs of each of the segments. The present invention is based on the recognition that providing a LED separated into at least two segments having a common electrode and which are individually controllable (i.e. they can be individually switched on or off) allows varying the light output produced by the LED without having to change the drive signal supplied to the common electrode of the segments. When a drive signal is applied to the common electrode, switching off one of the segments results in the increase of the current density through the other segment which, at nominal operation, produces a degradation of the light output performance because the internal quantum efficiency (IQE) of the LED drops (this effect is commonly known as the “droop effect”). In turn, variations in the light output performance may be used to embed data symbols. In this manner, a conventional LED driver may be used to provide a drive signal to the common electrode of the two segments, while modulation of the light output is performed by switching one of the segments on and off using e.g. switches which are external to the LED driver. This approach provides an advantage over the prior art in that such a device is compatible with conventional LED drivers since no additional electronics for modulating the drive signal are necessary, which enables simple implementation and reduced costs. As used herein, the term “nominal operation” is used to describe operation of a LED at such current density that desirably results in the maximum IQE of the LED. The light sources described herein may comprise inorganic or organic light emitting diodes. Data embedded in the light output of the illumination system may comprise localized identification information of the light sources, their capabilities and/or settings, or other types of information related to the light sources. However, it should be noted that the illumination system is not necessarily applied for the purpose of illuminating a space or area but may also be applied for data communication as such. As an example, the illumination system may constitute an access point to a network. For such applications, at least part of the light output produced by the illumination system may lie outside of the visible spectrum (i.e., the light output of one of the light sources of the system may lie outside of the visible spectrum). According to other aspects of the invention, a corresponding method for embedding one or more data symbols of a data signal into a luminance output of an illumination device as well as an illumination system comprising one or more illumination devices are provided. Embodiments of claims 2 , 3 , 9 , and 10 provide ways to define a modulation depth for the illumination device. As used herein, the term “modulation depth” refers to a range of variation in the amplitude or intensity of the luminance output of the LED, where different levels in the amplitude or intensity correspond to different data bits encoded in the luminance output. Embodiments of claims 4 , 5 , 11 , and 12 specify that the common electrode could be a cathode or an anode. Embodiment of claims 6 and 13 provide an advantageous type of the LED to be employed in the illumination device. Hereinafter, an embodiment of the invention will be described in further detail. It should be appreciated, however, that this embodiment may not be construed as limiting the scope of protection for the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of an illumination system according to prior art; FIG. 2 is a schematic illustration of an illumination system installed in a structure according to one embodiment of the present invention; FIG. 3 is a schematic illustration of an illumination system according to one embodiment of the present invention; FIG. 4 is a schematic illustration of implementation of a segmented LED approach according to one embodiment of the present invention; and FIG. 5 is a schematic illustration of the droop effect. DETAILED DESCRIPTION In the following description, numerous specific details are set forth to provide a more thorough understanding of the present invention. However, it will be apparent to one of skill in the art that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the present invention. FIG. 2 shows a structure 200 —in this case a room—with an installed illumination system 210 . The illumination system 210 comprises one or more of light sources 220 and one or more controllers (not shown in FIG. 1 ) controlling the light sources 220 . When driven with an electrical signal, the light sources 220 illuminate parts of the structure 200 . The light sources 220 may comprise inorganic and/or organic light emitting devices. The illumination system 210 may further comprise a remote control 230 allowing a user to control the light sources 220 . FIG. 3 is a schematic illustration of an illumination system 300 according to one embodiment of the present invention. The illumination system 300 may be used as the illumination system 210 in the structure 200 illustrated in FIG. 2 . As shown, the illumination system 300 includes a LED 320 which includes at least two individually controllable segments having a common electrode, a LED driver 310 configured to provide a drive signal to the LED 320 , and a data source 330 configured to provide data to be embedded into the light output of the LED 320 . The illumination system 300 is configured to operate as follows. As shown in FIG. 3 , the light settings for the illumination system 300 are provided to the LED driver 310 . The light settings may be e.g. provided by a user via the remote control 230 or may be preprogrammed and provided from an external unit controlling the scene setting. Alternatively, the light settings may be preprogrammed and stored in a memory within the LED driver 310 or within the illumination system 300 . The LED driver 310 translates the light settings into a drive signal for the LED 320 . In one embodiment, the LED driver 310 comprises a current source providing the drive signal in the form of a drive current. In such an embodiment, the LED 320 may be implemented as illustrated in FIG. 4 . As shown in FIG. 4 , the LED 320 includes an emitting portion 422 and a switching portion 424 . The emitting portion 422 is manufactured in such a way that n portions of the LED chip area can be partially isolated from the others, resulting in n segments, shown as D 1 , D 2 , . . . Dn, each of which is configured to emit light in response to the drive current. As used herein, n denotes any integer number equal or greater than 2. The segments D 1 , D 2 , . . . Dn have a common electrode. In FIG. 4 the common electrode is shown to be an anode 426 , but, in other embodiments and with modifications to the circuit that will be apparent to the person skilled in the art, the common electrode could be a cathode. The switching portion 424 includes (n−1) switches, shown in FIG. 4 as S 2 ,. . . Sn, where each of the switches S 2 ,. . . Sn is used to switch on or off a corresponding segment D 2 ,. . . Dn of the emitting portion 422 . Thus, a switch S 2 corresponds to a segment D 2 , a switch S 3 corresponds to a segment D 3 , and so on. When a constant drive current, shown in FIG. 4 as Idrv, is provided from the LED driver 310 and applied to the common electrode 426 and all of the switches S 2 ,. . . Sn are closed (i.e., the corresponding circuits are closed, the corresponding segments are switched on), the currents going through each of the segments, shown in FIG. 4 as currents I 1 , I 2 , . . . In, cause the segments to emit light. The sum of light contributions from each emitting segment comprises the luminance output of the LED 320 . As used herein, the phrase “constant drive signal” (which includes “constant drive current”) is used to reflect the fact that the drive signal is not modulated to embed data bits. This does not exclude drive signals consisting of pulses, as long as the pulses are not modulated to embed data signals, as was done in the prior art. Since the total drive current provided by the LED driver 310 remains constant, if one of the switches S 2 , . . . Sn would become open (i.e., the corresponding segment D 2 , . . . Dn is switched off), the current density in the segments that remain switched on would increase. Driving with the LED 320 with a nominal operation current (nominal operation here refers to all segments on), the increase in the current density through a segment after switching at least one other segment off produces a degradation in the light output performance of the emitting segment due to the droop effect. This effect is illustrated with a curve 510 in FIG. 5 , where the x-axis is used to show values of the drive current (in mA), the y-axis is used to show values of the wall-plug efficiency (in %) corresponding to a commercial LED device using approximately 1 mm 2 of active area. The right side of the curve 510 makes clear that increase in current results in decreased efficiency. Therefore, at nominal operation, due to the droop effect, when one of the segments D 2 , . . . Dn is switched off, the light output 325 produced by the LED 320 would decrease as the current density through the other segments increase. In order to utilize this effect, as shown in FIGS. 3 and 4 , the LED 320 further includes a controller 340 . The controller 340 is configured to receive a data signal 335 from a data source 330 . The signal 335 includes (at least) data bits to be embedded into the light output 325 of the LED 320 . In the present description, the symbols are referred to as bits. However, it should be recognized that whenever the word “bit” is used in the present application, a wider definition of a “symbol” applies which may also comprise multiple bits represented by a single symbol. For instance multi-level symbols, where not only 0 and 1 exist to embed data, but multiple discrete levels are defined to represent data. The controller 340 is configured to switch segments D 2 , . . . Dn on or off in response to the signal 335 in order to embed the data bits of the signal 335 into the light output 325 . The amount of emitting area corresponding to each of the different segments defines the intensity levels of the light output modulation. The number of segments that can be switched on or off defines the number of modulation levels. For example, for a two level modulation (i.e. each bit to be embedded is either “1” or “0”), only two segments within the LED 320 are required—one segment which is always switched on and another segment which could be switched on or off to embed data bits. Referring to FIG. 4 , such an embodiment corresponds to the emitting portion 422 comprising only two emitting segments, D 1 and D 2 . Continuing with this example, consider that decreasing the light output of the LED 320 by 10% can be resolved on the detecting side as a binary value of “0”. In such an exemplary embodiment, the size of the segment D 2 may be made to be approximately 10% of the total area of the emitting portion 422 and to embed a binary value of “0” from the signal 335 , the controller 340 would switch segment D 2 off (i.e., open the corresponding switch S 2 ). Persons skilled in the art will recognize other methods for switching the segments on and off in dependence of the signal 335 to embed data into light output of the illumination system. For example, multi-level modulation of the light output could be implemented by employing and switching larger number of segments than two. The larger the number of levels is, the higher the bit rate can get. Thus, in another embodiment, the emitting portion 422 comprises the segments D 1 . . . Dn. In practice n is an integer between 3 and 10, more preferably between 5 and 8, such as 6 or 7. Switching the segments D 2 . . . Dn using the switches S 2 . . . Sn enables implementing data with multiple discrete levels in the light output 325 of LED 320 . In an embodiment the relative sizes A2 . . . An of the segments D 2 . . . Dn are all equal. In another embodiment the relative sizes A2 . . . An are related to each other in a predefined relationship such that they continuously increase/decrease. For instance, An−1=2×An, so that A2=2×A3=2×(2×A4)=2×(2×(2×A5)), etc. In another embodiment the segments D 2 . . . Dn are designed such that their nominal operation current densities relate to each other similarly as described for the sizes above. In addition to operation in the mode where the controller 340 switches some of the segments on and off to embed data symbols of the data signal 335 , which could be referred to as a “transmission mode,” the LED 320 could also operate in DC mode as any other conventional LED device when switches S 2 -Sn remain in on-state. Namely, the current through the segments D 1 , D 2 , . . . Dn will flow uniformly provided that the on-resistance of the switches S 2 , . . . Sn is much lower than the dynamic resistance of the segments. Furthermore, in other embodiments, the LED driver 310 may comprise a voltage source providing the drive signal in the form of a drive voltage. Persons skilled in the art will readily recognize how the discussions provided above could be modified to accommodate the voltage source LED driver. One advantage of the present invention is that the drive signal provided by the LED driver to the LED does not need to be modulated to embed the data symbols because the data symbols are embedded via switching of the individual segments of the LED. As a result, conventional LED drivers may be employed, eliminating the need to include complicated and costly electronics capable of modulating the drive signal. While the forgoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. For example, aspects of the present invention may be implemented in hardware or software or in a combination of hardware and software. Therefore, the scope of the present invention is determined by the claims that follow.

The invention relates to an illumination device for embedding data symbols of a data signal into a luminance output of the illumination device. The device includes a LED comprising at least two segments which have a common electrode and are individually controllable. The LED is configured to generate the luminance output in response to a drive signal. The device further includes a controller configured for switching one of the segments on or off in response to the data signal to embed data symbols of the data signal into the light output of the device. One advantage of such an approach is that the proposed device is compatible with conventional LED drivers since no additional electronics for modulating the drive signal are necessary, which enables simple implementation and reduced costs.

FIELD OF THE INVENTION The present invention relates to a roofing system for a roof deck which is not steeply inclined, such as is found in commercial, as opposed to residential roofs. More specifically, the fastener-free roofing system of the present invention is directed to the use of a curable adhesive composition which will simply and safely secure roofing insulation to a roof deck without the need for mechanical fasteners. BACKGROUND OF THE INVENTION Flat Roofs in General In the roofing art, and in this specification, "flat roof" refers to a roof having a slope of less than about 25° relative to a horizontal plane. Many such roofs are substantially flat with a slight incline to allow water to run off. Some flat roofs comprise numerous sloping sections which create peaks and valleys, and a water drain is generally located at the bottom of each valley to facilitate water drainage. Flat roofs traditionally comprise three basic components (from top to bottom): (1) a waterproof membrane (top); (2) thermal insulation (middle); and (3) the structural deck (bottom). The waterproof membrane typically comprises two or more plies of a felt membrane in combination with bitumen (generally coal tar pitch or asphalt). The felt stabilizes and strengthens the bitumen, and distributes contractive tensile stress when the bitumen is cold and glasslike. Alternatively, the membrane can be a polymeric sheet or a series of polymeric sheets adhered together to form seams where they are joined. The membrane is typically used in combination with metallic and/or nonmetallic flashings which guard against leakage through portions of the membrane which are pierced or terminated, such as at gravel stops, walls, curbs, expansion joints, vents and drains. Mineral aggregate (normally gravel, crushed rock, or slag) is often spread atop the membrane to hold it down on the roof deck and protect the membrane from wind, rain, solar radiation, and fire. Such aggregate may be unnecessary on smooth-surfaced asphalt roofs having glass-fiber felts. Conventional membranes cannot resist large movements of the deck, or insulation covering it, and will be punctured by heads of fasteners which protrude above the insulation due to such movements. Membrane puncture (due to fastener heads, foot traffic or the like) and undue membrane shifting or movement (due to foot traffic, wind forces or the like) are primary causes for leaks in flat roofs which have been properly installed. Roofing Insulation The second basic component of a flat roof is the roofing insulation installed just beneath the membrane. Insulation may be provided by several materials, such as rigid insulation prefabricated into boards, or poured insulating concrete fills (sometimes topped with another more efficient rigid board insulation). The roofing insulation preferably has adequate shear strength to distribute tensile stresses in the membrane to prevent it splitting. The insulation should also have adequate compressive strength to withstand traffic, and the impact of hailstones. Furthermore, the insulation should have sufficient adhesive and cohesive strength to resist delamination due to wind uplift forces and the like. Finally, the dimensional stability should be sufficient to withstand thermal and moisture cycles. The Roof Deck The final component of a flat roof is the structural deck which lies below the insulation. The roof deck is generally a metal, concrete, gypsum or wood substrate which is generally integral with the building's basic structure upon which substrate the rest of the roof is built up. Uplift Forces Due to Winds Forces generated by wind currents are generally much greater at the top of most commercial buildings than they are at ground level, and the taller the building, generally the greater the wind forces upon a roof. Wind uplift pressure can damage a roof or even blow it off, unless it is properly anchored to the building. Leaks Due to Improper Anchoring of Insulation However, wind is not the only reason to firmly fasten down a roof. Unanchored insulation boards increase the risk of membrane splitting. Internal stresses produced by thermal and moisture changes in the membrane on a flat roof has a tendency to exert a ratcheting action on poorly anchored insulation. Flexible membrane expands and contracts during thermal cycles, thereby producing a cumulative ratcheting action toward the center of the roof. Over time, this ratcheting action can pull the insulation from the roof's edges, destroying the effectiveness of the edge flashing and of the roof. Mechanical fasteners can be used to secure the insulation to the roof deck. However, corrosion can be a problem. Although such fasteners can be coated with specialized anti-corrosive metals or polymers, such coatings can be partially removed as the fastener is ratcheted in place due to roof movement. Even a small breach in the coating can be sufficient to allow corrosion to infiltrate the entire fastener. Non-metal fasteners are perhaps possible, but would be very expensive due to the physical properties needed for such a fastener system. Even where the fastener does not corrode, fasteners will generally expand and contract with temperature changes, and holes through which fasteners are driven are therefore prone to enlarge over time, causing the fastener's holding ability to fail, or the fastener to back out through the membrane. Fasteners are also a problem because they provide the opportunity for moisture to penetrate into the insulation. Any leak in the membrane will generally cause water to flow to a fastener head, since the fasteners generally make indentations in the insulation they are anchoring (indeed, a leak in the membrane will often be near the head of a fastener because the head has punctured the membrane due to a fastener backing out, for example due to foot traffic). The use of fasteners is also labor intensive and subject to errors of workmen installing insulation on the deck. Eliminating fasteners for the insulation eliminates the possibility they might protrude through the insulation. SUMMARY OF THE INVENTION Many failed attempts substantially to satisfy the need for a fastener-free roofing system are of record in the art. The inventors herein have discovered that a surprisingly reliable roofing system may be formulated with an adhesive having desirable penetration and adhesion characteristics and desirably quick curing times. It is therefore an object of the present invention to provide a fastener-free roofing system which is inexpensive, easy to install and less prone to failure than conventional flat roof systems. Other objects and features of the present invention will become apparent to one of ordinary skill in the art, upon further reading of this specification and subsequent claims. The preferred roofing system of the present invention can be used with virtually any building having a roof deck which is not steeply inclined. The roofing system comprises a dispersion of a polyol and asphalt, or of a polyisocyanate prepolymer and asphalt as the adhesive which upon curing, secures a roofing panel (preferably of insulation) to a roof deck. Optionally, a vapor barrier can be placed between the roof deck and roofing insulation, and in this embodiment, the roofing adhesive is placed on each side of the vapor barrier. The adhesive of the present invention can also be used between insulation panels, between an insulation panel and the roofing membrane and also between membrane layers or sections. The adhesive of the present invention is relatively inexpensive, reliable and easy to use. The roof deck can be metal, wood, concrete, gypsum, or the like. The roofing insulation is preferably a rigid board made from either organic or inorganic materials. Other curing systems may include epoxy, acrylate, cyanoacrylates, silicone, and silane-hydration-condensation curing systems. The curing system can be a "one-part" or a "two-part" system. The most preferred curing systems are those which cure in about an hour. However, ordinary skill and experimentation might be required to adjust the rate of cure for any particular adhesive system used in an alternative embodiment of the present invention. The adhesive of the present invention is preferably substantially solvent-free, readily curable at typical ambient temperatures and preferably comprises a one-part dispersion of a polyisocyanate prepolymer and asphalt, or a two-part dispersion of a polyol and asphalt to which an isocyanate is added prior to applying a mixture of the two parts. Either dispersion optionally contains a filler. The preferred curing system is a one-part, isocyanate end-capped polyurethane prepolymer. A critical aspect of the present invention is that the adhesive has wetting and interdiffusion capability and quick cure time. The most preferred adhesive is a dispersion wherein asphalt which is liquid or semi-liquid at room temperature is suspended within a liquid prepolymer which is substantially solvent-free yet has substantial surface wetting capability. As a result, the liquid prepolymer can substantially wet the surface of the deck and also the surface of the insulation. The bitumen or asphalt particles suspended within the prepolymer droplets will generally not interfere with curing. Furthermore, bitumen and asphalt have some penetration and adhesion properties which might be advantageous. Such surface wetting is possible by applying the prepolymer without a substantial amount of asphalt or solvent carrier; however, such a system is not only uneconomical but also difficult to work with. The filler referred to above may be calcium carbonate, carbon black, clay, diatomaceous earth, or other commonly used fillers. Preferably such fillers are vigorously mixed into the prepolymer and most preferably suspended within prepolymer droplets. Ordinary skill and experimentation may be necessary to formulate an adhesive containing a filler which is not suspended in the prepolymer. A compatibilizing agent is necessary to obtain the dispersion of asphalt in prepolymer or polyol. Long cure times are generally disadvantageous, because the roof deck can shift due to wind forces or the like and deck may flex from traffic causing non-contact. Non-solvent adhesive systems of the present invention generally remain tacky and are capable of accommodating shifting, but will then quickly cure. Therefore deck shifts and irregularity are generally less of a problem in obtaining adequate adhesion. For porous insulation, such as fiber insulation, the adhesive must penetrate and anchor itself into the insulation fiber. The adhesive's filler and/or solvent must not substantially separate from the curing component as the insulation adhesive penetrates into the porous substrate. As the adhesive component cures, the polymer matrix should not be unduly interrupted by filler agglomerations or the like. The roofing adhesive is preferably temperature insensitive, particularly in the temperature range from about -40° F. (-40° C.) to about 160° F. (70° C.). The optimal coverage rate of the roofing adhesive is preferably about 0.5 to about 2 gals/100 ft 2 (gallons per hundred square feet), more preferably, 0.7 to about 1.5 gals/100 ft 2 . BRIEF DESCRIPTION OF THE DRAWINGS The FIGURE is a perspective view, with portions cut away, schematically illustrating a roof assembly constructed in accordance with the preferred embodiment of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The preferred roofing system of the present invention is shown generally at 8 in FIG. 1. Virtually any building having a roof deck (such as the metal deck shown at 10) can embody the present invention. The preferred roofing system comprises the adhesive 12 which secures the roofing insulation to the roof deck. Optionally, a vapor barrier 14 can be placed between the roof deck 10 and roofing insulation 18, and in this embodiment, the roofing adhesive 12 and 12' is placed on each side of the vapor barrier 14. A roofing membrane 20 is adhered to the roofing insulation by conventional means or with the insulation adhesive 12. The insulation adhesive can also be used to adhere insulation panels to one another. Aggregate 22 can be placed upon the membrane as an added protective layer. Finally, flashing members 24, and 26 are used to waterproof the edges of the building. The Roof Deck The roof deck 10 is integral with the primary support structure of the building and able to resist gravity loads, lateral loading from wind and seismic forces. Deck 10 is preferably about 18-24 gauge, cold rolled, galvanized steel having ribs 11 which are spaced apart at regular intervals such as about 6 inches on center and preferably define a depth of a few inches or so. Conventional prefabricated decks can also be used. Alternatively, the deck can be wood, gypsum or concrete. The wood sheathing can be sawed lumber or plywood. If the deck is concrete, it can be lightweight or structural concrete and can be cast in place or precast. A cast in place structural deck is preferably continuous, except where interrupted by an expansion joint or another building component. Gypsum can also be used in the practice of the present invention. A gypsum deck is preferably poured on gypsum formboards spanning flanges of closely spaced steel bulb tees. Such cast in place decks generally present large seamless expanses of roof surface, except where expansion joints are used to impede cracks from thermal contraction or drying shrinkage. The roof deck can also comprise mineralized wood fiber comprising long wood fibers bonded with a mineral or resinous binder and formed under a combination of heat and pressure. Preferably, the structural framing and deck are sloped to thereby provide an inclined roofing surface. The slope is preferably at least about 1/4th of an inch per foot. Such an incline is generally advantageous, since it will generally facilitate water run off and drainage. Although the present invention will generally work, at least to some degree, with roofs which pond water, such a roofing design is not preferred. Tapered insulation may be used to create a slope. The insulation 18 of the present invention is preferably a rigid board insulation, either organic or inorganic. The organic insulation includes the various vegetable-fiber boards and foamed plastics. Inorganic insulation includes glass fiber, perlite, and wood fiber board. The board insulation can be cellular or fibrous. Cellular insulation includes foamed glass and foamed plastics, such as polystyrenes, polyurethanes and polyisocyanates. Fibrous insulation includes various fiberboards, which can be made of wood, cane, or vegetable fibers. The materials can be impregnated or coated with asphaltic materials to make them more moisture resistant. Fibrous glass insulation consists of nonabsorbent fibers formed into boards with resinous binders and can be surfaced with an organic material, such as paper. Perlite board contains both inorganic (expanded siliceous volcanic glass) and organic (wood fibers) materials bonded with asphaltic binders. Composite boards comprise a cellular plastic insulation on top and perlite, fiberglass, or fiberboard laminated on the bottom. The cohesive strength within the insulation must be at least equal to the required wind uplift resistance designed for the roof system to prevent the insulation from breaking in high winds. Adhering Insulation To The Roof Deck To secure the roofing insulation to the roof deck, an appropriate adhesive is necessary. The problem with many decks, particularly steel decks, is that they tend to deflect due to wind, surface traffic or the like. The adhesive 12 used in the present invention preferably has sufficient elasticity to withstand conventional deflections, even by a steel deck, without diminishing the bond strength between the deck and insulation. The adhesive 12 is preferably capable of substantially maintaining adhesive integrity even after normal steel deck deflection, and the adhesive preferably has sufficient elasticity and adhesiveness to diminish dishing or differential deflection due to wind, foot traffic or the like. Furthermore, the adhesive 12 quickly obtains bond strength. The adhesive preferably provides sufficient adhesion between a roof deck and insulation to withstand about 90 pounds per square foot uplift. Bonding sufficient to withstand 90 pounds per square foot uplift should be obtained within about 24 hours, more preferably 5 hours. In just two hours under favorable conditions (40-80% relative humidity, 18°-23° C.). Upon full cure, preferably within about 24 hours, the adhesive is preferably able to resist 100 pounds per square foot and more preferably 115 pounds per square foot or more. The curing system can be one-part or more than one part. The most preferred curing systems are those which gel in about an hour. Where curing substantially occurs within 5 minutes or less, often there is insufficient time for the workers to apply the insulation upon the applied adhesive layer, and if so, the adhesive will cure without adequate bonding to the insulation substrate. However, where substantial curing occurs only after more than about 24 hours, deflections in the roof deck, particularly in a steel roof deck, will often tear the insulation away from the deck prior to full adhesive curing, substantially increasing the possibility of adhesive failure or non-contact and non-penetration into the insulation. Ordinary skill and experimentation might be required to adjust the rate of cure for any particular adhesive system used in an alternative embodiment of the present invention. The adhesive 12 is preferably substantially solvent-free, readily curable at typical ambient temperatures and relative humidity. The preferred curing system is a one-part, isocyanate based moisture curing system. Other curing systems are also possible, such as two part isocyanate or urethane systems, one or two part epoxide systems, room temperature curable polysulfide systems, silicone, and the like, provided the curing system is capable of providing 90 pounds per square foot uplift resistance in less than about 24 hours. Ordinary skill and experimentation may be necessary in optimizing any alternative curing system used in an alternative embodiment of the present invention. The most preferred adhesive is substantially solvent-free and has substantial surface wetting capability. The most preferred method of adhesion is to have an inverse dispersion wherein asphalt, and optionally a filler, is suspended within an organophilic liquid prepolymer. As a result, the liquid prepolymer can substantially wet the surface of the metal. The most preferred filler is asphalt or bitumen, particularly asphalts or bitumens which are liquid or semi-liquid at room temperature. The bitumen or asphalt particles suspended within the prepolymer droplets will generally not interfere with curing. Furthermore, bitumen and asphalt have some penetration and adhesion properties which might be advantageous. A compatibilizing agent is necessary to obtain an inverse dispersion. Other fillers might also be used, such as calcium carbonate, clay, diatomaceous earth and the like. Preferably such fillers are vigorously mixed into the prepolymer and most preferably suspended within the prepolymer. Where dispersion of the filler is not obtained, then the filler can interfere with the prepolymer wetting onto the surface and subsequent cure. Ordinary skill and experimentation therefore may be necessary in formulating any adhesive having a filler which is suspended in the prepolymer. As mentioned above, solvents are less preferred. Long cure times are generally disadvantageous, because the roof deck can shift due to wind forces or the like and substantially diminish potential adhesion. The non-solvent system of this invention generally remains tacky and capable of accommodating shifting and will then quickly cure. Adhesion is not only important with respect to the surface coating on the metal deck, it is also important in wetting the surface of the insulation. For porous insulation, such as fiber insulation, or for a porous roof deck, such as concrete or wood, the organophilic adhesive must penetrate and anchor itself into the porous substrate. The amount of penetration to anchor the adhesive into the insulation (and porous roof deck, if used) may have to be determined by routine experimentation. The adhesive's filler and/or solvent should not substantially separate from the curing component as the insulation adhesive penetrates into the porous substrate. As the adhesive component cures, the polymer matrix should not be unduly interrupted by filler agglomerations or the like. Before the adhesive can be applied to the roof deck, the surface should be chemically or mechanically cleaned using conventional methods. Also a conventional primer can be used. The Most Preferred Insulation Adhesive The preferred insulation adhesive of the present invention comprises a base material (asphalt) component, a liquid prepolymer ("curable") component, and a non-volatile compatibilizer. The base material component is used primarily due to its low cost, although such components may also provide advantageous properties, such as good wetting, reinforcement value and/or waterproof and weather resistance properties. The prepolymer component is primarily present to polymerize within the base material subsequent to application, thereby providing a polymer network within the base material which provides strength and cohesion (the polymer network preferably contains urethane groups or the like which also provide desirable elastomeric properties and chemical bonding to surfaces). The compatibilizer is used to promote intermixing of the prepolymer and the base material and maintain a stable suspension. The Adhesive's Base Material Component The base material component can be any substantially non-volatile organic material, such as bitumen, asphalt, tar, substantially non-volatile petroleum based materials, and the like. The asphalt or bitumen component is most preferred and can be any commercially available bitumen material common to the industry. Preferably, the bitumen is substantially free of water and is substantially free of heterocyclic compounds or compounds which have reactive sites which will react with isocyanates. It has also been found that base materials with low softening points, such as less than about 200° F. and preferably about 120° F. or less, generally work better in the present invention than base material with higher softening points. The lower softening points generally provide easier intermixing with the prepolymer when using the compatibilizer in this invention than base materials with higher softening points. A plasticizer or other non-reactive diluent is preferably added to the base material to further soften the base material, making it easier to intermix with the prepolymer component. The base material component can sometimes contain reactive sites which will react with the prepolymer component, such as: thio (--SH) or amino (--NH 2 ) functional groups and the like. Such reactive sites can be detrimental to the preferred embodiment of the present invention, particularly in a one component version of the present invention (one and two component systems are discussed below in the section entitled "Curing"). Therefore to prevent unwanted reaction between these reactive sites and the prepolymer component, the asphalt should first be pretreated with a blocking group, such as a reactive isocyanate (such as a para-toluene-sulfonyl isocyanate or the like), anhydride or carbodiamide. Suitable blocking agents include phthalic anhydride, succinic anhydride, or maleic anhydride. The anhydride will generally also dispose of any water within the base material, and water has been found generally to also be detrimental to the preferred embodiment of the present invention. The preferred amount of blocking group to be added to the asphalt is about 0.0 to about 5 weight percent, although the optimal amount of the blocking group can depend upon the particular end-use of the material and the type of base material, and therefore the blocking agent may have to be determined by ordinary skill and experimentation. The Adhesive's Prepolymer Component A second component of the preferred embodiment of the present invention is a liquid curable prepolymer, most preferably a polyisocyanate prepolymer system. This preferred polyisocyanate prepolymer is formed from the reaction of an organic polyisocyanate, preferably a diisocyanate, and an organic polyol. The hydroxyl group of the polyol will react with the isocyanate group of the polyisocyanate, and the resulting addition reaction will link the polyol to the polyisocyanate, creating a urethane at the junction of the previously separate molecules. The basic reaction of the diisocyanate with the hydroxyl is a hydrogen exchange, where the hydrogen of the polyol attaches itself to the carbon of the isocyanate, and conversely, the hydrogen of the isocyanate becomes attached to the hydroxyl oxygen, becoming a urethane. However, the isocyanate functional groups are preferably in substantial excess, and therefore, the polyol molecules will add to the polyisocyanate molecules until the polyol molecules are substantially or completely depleted, and the resulting (prepolymer) molecules will have unreacted isocyanate functional end groups. The resulting molecules preferably have about 1 to about 10 isocyanate functional groups per molecule. The prepolymer therefore contains rather large molecules having isocyanate functional end groups. The functional groups will be reaction sites during curing. Curing is discussed below under the section heading "Curing". Virtually any polyisocyanate can be used, including for example methylene di-para-phenylene isocyanate ("MDI"), toluene diisocyanate, polymethylene-polyphenylene-diisocyanate, isophorone diisocyanate, and mixtures thereof. Triisocyanates and higher polyisocyanates also work well. The most preferred polyisocyanates are aromatic polyisocyanates, such as MDI. Suitable polyols (for reacting with the polyisocyanate to thereby form the polyisocyanate prepolymer) preferably have urethane or urea forming constituents, such as polyether polyols and less preferably polyester polyols, including diols and triols such as glycerine. However, acrylated polyols do not work well in the present invention. Suitable polyols include ethylene glycol, propylene glycol, diethylene glycol, polybutadiene polyols, polytetrahydrofuran polyols, and polycarbonate polyols, and caprolactone-based polyols. Such polyols can be reacted with an alkylene oxide including ethylene oxide, propylene oxide and butylene oxide for example, to form polyether polyol adducts useful in forming the polyisocyanate prepolymer. The polyol can have a weight average molecular weight ranging from as low as about 250 to about 10,000 or more. Less preferred polyols are polyester polyols, since they have been found to be rather water sensitive and somewhat more temperature sensitive. The polyisocyanate prepolymer is mixed with one or more non-reactive diluents, preferably plasticizers. These non-reactive diluents advantageously modify (typically decrease) the viscosity of the material. The preferred non-reactive diluents also typically make the end product less temperature sensitive, i.e., more durable when used at temperatures greater than about 150° F. Preferred plasticizers include dibutoxyethyl phthalate ("DBEP"), diisodecyl phthalate ("DIDP"), dibutyl phthalate ("DBP"), butylbenzyl phthalate ("BBP"), dioctyl phthalate ("DOP"), dioctyl sebacate ("DOS"), dioctyl adipate ("DOP") and diethylbutyl sebacate ("DEBS"), dibutoxyethoxyethyl sebacate, dibutoxyethyl sebacate, dibutyl sebacate, dioctyl dodecanedioate, diisooctyl dodecanedioate, dioctyl sebacate, dioctyl sebacate (substituted), triisooctyl trimellitate, trioctyl trimellitate, diisooctyl adipate, dioctyl adipate, dioctyl azelate, long chain alkyl alkylether diester, dialkyl diether glutarate, dibutoxyethoxyethyl glutarate, dibutoxyethyl glutarate, tributyl phosphate, and still bottom phosphate plasticizers. Plasticizers derived from phthalic acid are more preferred, and butylbenzyl phthalate is most preferred. The plasticizer reduces the viscosity of the prepolymer and the asphalt, making them more fluid and therefore somewhat easier to intermix. The amount of prepolymer used in the present invention should be adequate to provide a coherent, substantially homogeneous mass. Typically this will mean that the prepolymer is present in a weight percentage of about 20-90%, preferably about 50%. The Adhesive's Compatibilizer Component The third ingredient of the preferred embodiment of the present invention is a compatibilizer which is defined as any material which will aid in inverting the base material within the liquid prepolymer system, and aid in causing the base material to be dispersed within the liquid prepolymer system. The most preferred compatibilizer is a surfactant-type material, having a substantially non-polar portion and a substantially polar-organic portion. The most preferred compatibilizer comprises a polymer unit, or two such units being either identical or different linked together by an ester, carbon or ether bond, said unit having the following formula: CH.sub.3 --(C.sub.n H.sub.2n)--R.sub.1 wherein: n is 4 or more, and R 1 is COOH, COO - M + , COOR 2 or R 2 , preferably COOR 2 , wherein: M is a metal, preferably zinc, and R 2 is a substantially saturated organic chain having a backbone substantially comprising carbon-carbon, carbon-oxygen, or carbon-nitrogen linkages, or combinations thereof, wherein the backbone's pendent constituents are either --H or --OH and wherein at least one pendent constituent is --OH. The most preferred compatibilizer is obtained where n is 12 or more, and R 1 is COOR 2 . The paraffinic portion of the most preferred compatibilizer, CH 3 --(C n H 2n )--, is generally very compatible with the asphalt. In general, the longer the chain, the more compatible the molecule will be with the asphalt, and therefore if the chain is relatively short, more compatibilizer molecules will generally be needed to suspend or invert the base material within the liquid prepolymer. The semi-polar portion of the most preferred compatibilizer polymer, --R 1 , has been found to be very compatible with polyisocyanate prepolymer, plasticizers, and most additives used in asphalt systems which are substantially non-polar, but have polar-organic portions, such as urethane-type polarity. In the preferred embodiment, the hydroxyl constituent(s) of the semi-polar portion of the polymer is compatible with the urethane linkage of the prepolymer (or any other organic segment having a polarity substantially similar to urethane). In the preferred embodiment, the hydroxyl group(s) will tend to move to the urethane linkage(s) and will tend to pull the compatibilizer in relative close proximity to the pre-polymer molecule. In addition to the hydroxyl groups, the semi-polar portion of the preferred compatibilizer will also have hydrocarbon groups which are substantially non-polar and which are compatible with the non-polar portion, the asphalt. As a result, the hydroxyl group will help suspend the urethane or similar type portion of the prepolymer, and the rest of the semi-polar portion of the prepolymer while the paraffinic portion of the compatibilizer will generally help suspend the base component. The compatibilizer lifts the base material and prepolymer into suspension within the prepolymer system, enabling them to be thoroughly and easily intermixed. Regarding the paraffinic portion of the compatibilizer, the flexibility of the paraffinic chain is important and aids in the compatibilizer's ability to suspend the base component. Therefore any double or triple bonds or the like would be detrimental to the paraffinic portion. Furthermore, the non-polar character of the paraffinic chain is also very important. Modifications to the paraffinic chain will generally be detrimental to the compatibilizer, if they make the non-polarity less uniform. In general, even slight deviation from a pure paraffinic chain will generally reduce compatibility. The semi-polar portion of the compatibilizer however can be varied in a number of ways and is more difficult to define. As with the paraffinic portion, chain flexibility is also important. Chain flexibility aids in the compatibilizer's ability to suspend both the prepolymer and the base material. The preferred prepolymer generally has numerous urethane linkages, as well as urea linkages and other components having some organic polarity. The polarity of the oxygen and nitrogen portions of the polymer backbone generally are very compatible with these portions of the prepolymer. As a result, although the semi-polar portion may be less able to suspend certain (non-polar) portions of the prepolymer due to the presence of oxygen or nitrogen, the increased chain flexibility enhances compatibility and the polarity due to the oxygen and nitrogen aids in suspending other polar portions of the prepolymer. The ester linkage between the paraffinic portion and semi-polar portion has generally been found to be advantageous, although a precise explanation for this cannot be given. One explanation might be that the ester provides a stiff link between two very flexible portions of the compatibilizer molecule. Since the two portions are intended to suspend two different components, perhaps the ester aids in keeping the two portions separate and interactive with their intended component. Perhaps the relatively high polarity of the ester draws the hydroxy portion (and therefore the prepolymer) into close proximity to the paraffinic portion (and therefore the asphalt), thereby allowing improved intermixing. In any event, ester linkages are preferred within the transition zone between the paraffinic side and semi-polar side but are not preferred as part of either of these two sides. Hence the compatibilizer might be better visualized as having a paraffinic side, a transition portion and semi-polar side. Fatty acids are relatively inexpensive and relatively plentiful. Numerous fatty acids were researched, and it was found that they generally provide noteworthy compatibility (significantly diminish the need for solvent in mixing base material and prepolymer). Metal salts of these fatty acids were also tried, using metals such as zinc, and the salts also provided noteworthy compatibility. The fatty acids were then reacted with polyols and compatibility generally increased. Compatibility was best when a diol or polyol, particularly a diol, was used to thereby provide a paraffinic chain attached by an ester linkage to a flexible chain having one or more hydroxyl groups. Compatibility was generally better where only one hydroxyl group existed on the chain, preferably toward the terminal end of the chain. Fatty acids were reacted with diols, particularly ethylene glycol and propylene glycol. The best compatibility was achieved when reacting stearic acid and propylene glycol to produce propylene glycol monostearate. The polystearate version of this molecule, bis stearyl ester polypropylene diol, also provided excellent compatibility. Further work was therefore done, and it was found that the paraffinic/semi-polar molecule could be linked with another paraffinic/semi-polar molecule (either the same or different) with an ester, ether or carbon linkage, and the resulting molecule would generally work well as a compatibilizer. However three such molecules linked together generally did not give good compatibility results in the preferred embodiment. Polyhydric alcohols were researched, particularly triethylene glycol. Triethylene glycol caprate caprylate and triethylene glycol dipelargonate both provided noteworthy compatibility, and it is believed that most alcohols reacted with a fatty acid will provide compatibility, at least to some degree. Polyols with ether groups were reacted with fatty acids and found to also provide exceptional compatibility. Having read the present disclosure and with knowledge of the numerous compatibilizers described above, the ordinary artisan should easily be able to develop obvious variations of the preferred compatibilizer of this invention. Depending upon the end-use and performance requirements of the end-product, an obvious variation of the preferred embodiment may be more suitable. For example, the greater the amount of base material to be compatibilized, typically the more important the paraffinic portion of the compatibilizer. Either the paraffinic chain should be very long or a large number of such chains should be present. If a lesser amount of asphalt is used, the optimal compatibilizer may be primarily dependant upon the semi-polar portion of the compatibilizer. If the prepolymer is substantially non-polar, then the semi-polar portion of the compatibilizer should generally be non-polar. If an increased amount of urethane portions are present or if the prepolymer is rather polar, then more hydroxyl groups may be required or more ether linkages to obtain the optimal compatibilizer. It would be impossible to test and describe all possible variations of the preferred embodiment with respect to all possible base material-prepolymer systems and such has been left to the skills of the ordinary artisan after having read the present specification. The compatibilizer preferably is present in the range of about 0.01% to about 5% with 0.1% being most preferred (all percentages herein are percentages by weight unless otherwise indicated). The compatibilizer of this invention substantially diminishes the need for a volatile organic solvent, because the fatty acid derivative (or non-derivative) surprisingly provides sufficient miscibility among the material components to form a flowable, sufficiently intermixed system. The resulting material can be easily blended or mixed and can be pumped and sprayed. The compatibilizer will not interfere with most chemical reactions commonly used in asphalt systems and can be used in a one-part or a two-part system. Unlike traditional organic solvents which can be an environmental and health hazard, the compatibilizer of the present invention is non-volatile and generally relatively non-toxic in comparison to conventionally known solvent systems. Curing Of The Adhesive The polymerization reaction of the isocyanate prepolymer is commonly referred to as "curing". Prior to curing, the mixture is substantially flowable at ambient temperatures, but after curing, the resulting polymer network is a non-flowable, non-moldable elastomeric solid. Curing creates an adhesive bond between the roof deck and roofing insulation. The roofing insulation adhesive generally provides excellent sealant properties, because the asphalt component will generally penetrate into the roof deck surface, thereby providing the prepolymer with a substantial contacting surface upon which to bond as it cures. The asphaltic material of the present invention is preferably stored and transported in its uncured state. The mixture is preferably applied and then allowed to cure. Curing can be initiated in a number of ways. In a one-part system, curing is initiated and propagated by moisture, preferably humidity from the air. As a result, the uncured material is generally transported and stored in a substantially water-free environment. When the material is applied and exposed to ambient conditions, the moisture in the air will react with the prepolymer's isocyanate functional groups, creating an amine (urea) and giving off carbon dioxide as a by-product. The amine will in turn readily and quickly react with any other isocyanate functional group present. The amine-isocyanate reaction is an addition reaction which links the two prepolymer chains together, creating as disubstituted urea functional group at the connection point of the two prepolymer chains. This curing reaction creates a polymer network within the base material which provides strength, cohesion, adhesion and elastomeric properties. A plethora of other curing reactions could also be used. A secondary curing agent could be added to the one part system which would also react with moisture to create a reaction product (typically an amine) which would initiate and/or propagate the prepolymer polymerization. Such secondary curing agents are often found to be useful, because the curing reaction does not produce carbon dioxide as a bi-product which may be advantageous for certain applications. Secondary curing agents for one part isocyanate based polymerization reactions are well known in the art, such as oxazolidine or ketimine. In a two-part system, a curative is mixed into the system just prior to application. In such systems, a large number of acceptable curatives are well known in the industry. Acids, amines, hydroxyl, or virtually any hydrogen or proton donating molecule can be used to initiate and propagate the polymerization of an isocyanate prepolymer. One-part systems are generally preferred however, because end-users typically find that mixing prior to application is unduly burdensome, particularly if certain mixing equipment is necessary or if the length of time and quality of mixing has a small margin for error. Regardless of whether a one-part or two-part system is used in the preferred embodiment, a large excess of isocyanate will often also advantageously create a strong cross-linked polymer network, because the urethane or disubstituted urea groups (created at the junction point of two prepolymers) can themselves react with isocyanate to form an allophanate (RNHCOHR'COOR') in the case of a urethane reaction or a substituted biuret (RNHCONR'CONHR") in the case of a disubstituted urea reaction. Other Additives Other additives can be added to modify the physical properties of the resulting compound. Optional ingredients which can be used include for example, those catalysts (i.e., imidizole tin or other known metal catalysts), fillers and additives conventionally used in base material isocyanate based polymers, such as antioxidants, protectants and the like. If the curing reaction gives off carbon dioxide (as when water reacts with an isocyanate functional group), an absorbent can be used, such as molecular sieve, to absorb the carbon dioxide, thereby substantially preventing unwanted bubbles or the like which may occur with the evolution of gases during curing. Preferred fillers would include organoclays, Such fillers preferably comprise platelets having long chain organic compounds bonded to its two faces. When used as a filler and when the system is at rest, the organoclay's long chain components will agglomerate, making the system thick and solid-like. However, when a shearing force is applied, such as when the material is moved and/or applied, the long chain components will disperse, creating an emulsion which will aid in the flow properties of the material (the organo-clay will no longer thicken the material unless or until it once again comes to a rest and the long chain components once again agglomerate). Such fillers allow for easy application, since they do not substantially impede the flow capabilities of the compound while the compound is being applied, and such fillers also thicken the material once it comes to rest, thereby substantially preventing the material from flowing away from the area to which is was applied. Other possible additives would include those modifiers and additives conventionally used in the formation of natural and synthetic elastomers. Such additives include flame retardants, reinforcements (both particulate and fibrous) heavy and light fillers, UV stabilizers, blowing agents, perfumants, antistats, insecticides, bacteriostats, fungicides, surfactants, and the like. Additionally, it should be recognized that additional conventional elastomers can be included as an ingredient in forming the asphalt material of this invention. Such additional elastomers include for example, polysulfide, EPDM, EPR ethylene, propylene diene monomer, ethylene propylene terpolymer, polychloroprene, polyisobutylene, styrene-butadiene rubber, nitrile rubber, and the like. The Insulation Adhesive Is Substantially Solvent-free The resulting material is free of solvent evaporation stress (i.e. cracking, blistering and the like) common to many solvent-based systems. The compatibilizer also surprisingly enhanced the resulting material "green strength"--that is, the ability of the asphalt adhesive to be tacky and to adhere during the transition period between the cured and uncured states. The high green strength of the present adhesive is advantageous, because the adhesive generally can be used without the need for clamps or similar-type devices since the material will adhere and bond virtually on contact. The adherence and bonding will increase as the curing progresses. Preferred Method of Manufacturing A one-part system is preferred since it eliminates the need for two-component mixing just prior to application, and the preferred method of manufacturing the one-step system, in which all reference to "parts" refers to "parts by weight" unless otherwise stated, is as follows: 1. The prepolymer is mixed at a slightly elevated temperature (140°190° F.) in a substantially water-free environment and comprises (in parts by weight of final material, not parts by weight of prepolymer material): a) about 20 to about 75 parts, and most preferably about 34 parts of about 2000 equivalent weight polyol; b) about 2 to about 15 parts, and most preferably 7 parts non-reactive diluent, preferably plasticizer; c) about 2 to about 20 parts and most preferably about 7 parts of about 150 equivalent weight diisocyanate; and d) a trace amount of catalyst (preferably tin) preferably at least about 0.01 parts. 2. The prepolymer preferably comprises about 20 to about 90 parts, preferably about 50 parts of the final material. The prepolymer is set aside and not used until step 10 below. 3. The asphalt component is heated in a substantially water-free environment to its softening point or until it is substantially a fluid. The amount of asphalt is preferably about 10 to about 80 parts, most preferably 38 parts. The asphalt should be continually heated to its softening point in a substantially water-free environment throughout the following manufacturing steps. 4. The non-reactive diluents (most preferably plasticizer(s)) are added to the heated asphalt. The amount of non-reactive diluents is preferably about 2 to about 20 parts, most preferably about 9 parts. 5. The blocking agent, preferably an anhydride, isocyanate or carbodiamide, is added. The preferred amount of blocking agent is about 0.2 to about 5 parts, most preferably about 0.6 parts. 6. The materials are mixed until all materials are dispersed or dissolved. 7. A catalyst is added (preferably tin, imidazole, or other metal catalyst). The preferred amount of catalyst is at least about 0.1 parts per million. 8. Mixing is continued and any desired additives are added (thickeners, thixotropes, antioxidants and protectants). The preferred amount of additives is about 2 to about 25 parts. 9. The compatibilizer is then added. The preferred amount of compatibilizer is at least about 0.01 parts, most preferably about 0.05 parts. 10. The prepolymer is added and the mixing is continued until all materials are dispersed or dissolved. 11. Allow the mixture to cool and store in a substantially water-free environment. Example 1 1. The prepolymer was mixed at room temperature in a substantially water-free environment and comprises (in parts of final material, not parts of prepolymer material); a) 34 parts of a 2000 equivalent weight polyether triol; b) 7 parts butyl benzyl phthalate; c) 7 parts of diphenyl methane diisocyanate; and, d) a trace amount of tin catalyst, about 1 ppm. 2. The prepolymer was set aside in a substantially water-free environment and not used until step 10 below. 3. 38 parts of industrial grade asphalt was heated in a substantially water-free environment to its softening point. The asphalt was continually heated and mixed at its softening point in a substantially water-free environment throughout the following manufacturing steps. 4. About 9 parts of butyl benzyl phthalate was added to the heated asphalt. 5. 0.6 parts of maleic anhydride was then added to the heated asphalt. 6. The asphalt mixture was mixed for about 10 minutes until all materials were dispersed or dissolved. 7. A trace amount of tin catalyst was then added, about 0.05 parts, and the asphalt was mixed for about 2 hours. 8. 1 weight part of a precipitated silica thixotrope filler and about 4 parts of a calcium carbonate particle filler was then added. 9. 0.5 parts of propylene glycol monostearate was then added. 10. The asphalt was mixed until all the materials were dispersed or dissolved and then the prepolymer was added and mixed about 30 minutes until all materials are dispersed or dissolved. 11. The final mixture was allowed to cool and was stored in a substantially water-free environment. The above mixture was tested as an insulation adhesive and found to properly cure overnight to a commercially acceptable elastomer under most common outdoor weather conditions. The overnight relative humidity can be as low as about 30% and the overnight temperature can be as low as about 0° F. and the material will properly cure in about 10 to about 20 hours. At higher temperatures and relative humidities, the material will cure much more quickly. The cure time can be adjusted by increasing or decreasing the amount of catalyst in the formulation or by adding an intermediate water curing component in place of the catalyst, such as oxazolidine or ketimine. The oxazolidine or ketimine can be added in place of the catalyst in an amount of about 0.1 to about 2 parts, preferably about 0.5. Upon curing, the resulting product of Example 1 had excellent peel adhesion, tensile adhesion and lap shear. The material was very durable and water and weather resistant. Alternatively, a two-part adhesive can be manufactured wherein the above material is mixed with an amine or other hydrogen donating compound just prior to application. The amine will react with the prepolymer typically much more readily than will water. As a result, the material will cure much more quickly and will not significantly react with water (and therefore will not significantly give off carbon dioxide as a by-product). Alternatively, a blocking group can be incorporated onto the isocyanate functional groups so that the material will not react with water. A curative can then be mixed with the material just prior to application which will remove the blocking group and initiate and/or propagate curing. The chemistry relating to polymerization of isocyanate prepolymers is well developed and a full discussion of one component and two component curing systems would be so voluminous as to be inappropriate in light of the fact that the present invention is not directed to any particular curing system. An exhaustive discussion of curing systems is unnecessary and may obscure the present invention. Such curing systems are readily known or can be readily developed by an ordinary artisan, using routine experimentation and knowledge well known in the art. The above discussion has been provided to aid in the understanding of the present invention. Details provided above are provided primarily to help the ordinary artisan visualize the preferred embodiment and the innumerable other possible embodiments of this invention, and such details are not intended to create any limitations to this invention. Many improvements and modifications are certainly possible and it would be impossible to explicitly describe every conceivable aspect of the present invention. Therefore, the failure to describe any such aspect is also not intended to create any limitation to the present invention. The limitations of the present invention are defined exclusively in the following claims and nothing within this specification is intended to provide any further limitation thereto.

The present invention relates to low slope roofing systems, particularly in commercial (as opposed to residential) roofing applications. More specifically, the fastener-free roofing system of the present invention is directed to the use of a curing adhesive composition which will simply and safely secure roofing insulation to a roofing deck without the need for mechanical fasteners.

FIELD OF THE INVENTION [0001] The present invention relates to removal of hydrogen sulfide (H 2 S) from gas streams, such as natural gas and combustion flue gases, and the production of potassium-sulfur fertilizers. BACKGROUND OF THE INVENTION [0002] In the pollution control field, several approaches are used to remove hydrogen sulfide from natural gas (sour gas) and from gases produced by the burning of a fossil fuel in reducing environments such as is done by gasifiers, such as those that are used in the power, steel, and paper (including black liquor) industries, coking processes, and the like. Many water and wastewater treatment processes remove hydrogen sulfide (H 2 S) removal for odor control. [0003] One conventional approach for removal of H 2 S involves the use of absorbing solutions such as complex amines, caustic soda, soda ash, and other strong alkali compounds. Another conventional approach involves removing H 2 S with a Claus reactor in which part of the H 2 S is oxidized to SO 2 and the remaining H 2 S is reacted with the SO 2 across a catalyst to form sulfur. By and large, the most widely used approaches to removing hydrogen sulfide from gas involve these post-combustion clean up methods. [0004] Major disadvantages of the conventional methods for H 2 S removal are the cost and complexity of the processes, the high operating costs, including the cost of reagents, and the high cost of disposal of waste. [0005] For these and other reasons, it is desirable to provide methods for removing H 2 S from natural gas and gas streams, like flue gas streams, that overcome the various problems associated with conventional methods for removing H 2 S. SUMMARY OF THE INVENTION [0006] In accordance with an embodiment of the invention, a method of scrubbing hydrogen sulfide from a gas stream comprises contacting the gas stream with a potassium-based substance, such as potassium hydroxide, effective to remove the hydrogen sulfide from the gas stream as a reaction product and then converting the reaction product to a fertilizer based on potassium and sulfur. The potassium hydroxide may be produced on site from potassium chloride (KCI or potash). [0007] A host of advantages are realized by practicing the methodology of the invention. One advantage is that a relatively high removal of H 2 S is achieved. The methodology also results in the production of a high value potassium-sulfur based fertilizer and, optionally, hydrochloric acid. [0008] The process permits many choices of reagents for H 2 S control with potassium alkalis being the preferred reagents because of gas phase reactions in the removal stage, production of a potassium sulfate final product, and the ability to make the potassium alkali on site from potassium chloride. [0009] These and other advantages of the present invention shall become more apparent from the accompanying drawings and description thereof. BRIEF DESCRIPTION OF THE DRAWING [0010] The accompanying drawing, which is incorporated in and constitutes a part of this specification, illustrates embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serves to explain the principles of the present invention [0011] The Figure is a flow diagram in accordance with the present invention. DETAILED DESCRIPTION [0012] A wet hydrogen sulfide scrubber, shown in the Figure and denoted by numeral 10 , employs a properly designed absorber system employing mass transfer contact surfaces, sprays, trays, packing, and the like. The vessel of hydrogen sulfide scrubber 10 is designed to handle the pressure of a gas stream 12 containing hydrogen sulfide (H 2 S) and made of properly selected corrosion resistant materials. This hydrogen sulfide scrubber 10 is designed to meet the H 2 S removal requirements of a final clean or sweet gas stream 14 and is preferably adequate at removing H 2 S up to 99% or higher. [0013] The primary reaction that occurs in the hydrogen sulfide scrubber 10 uses potassium hydroxide (KOH) and is given by: [0014] 1 ) KOH+H 2 S→KHS+H 2 O An oxidizer sub-system 20 of the hydrogen sulfide scrubber 10 receives the KHS from the hydrogen sulfide scrubber 10 . In the oxidizer sub-system 20 , a number of reactions take place depending upon the operating conditions. The partial oxidation reactions are: [0016] 2) 2KHS+2O 2 →K 2 S 2 O 3 +H 2 O (potassium thiosulfate) [0017] 3) 2KHS+3O 2 →2KHSO 3 (potassium bisulfite) [0018] 4) KHS+2O 2 →KHSO 4 (potassium bisulfate) The total oxidation reactions are summarized below. Each total oxidation reaction produces potassium sulfate with the addition of potassium hydroxide, potassium bicarbonate, potassium carbonate, or a mixture of two or more of these potassium-based substances, but potassium hydroxide would be used most often: [0020] 5) KHS+2O 2 +KOH→K 2 SO 4 +H 2 O [0021] 6) KHS+2O 2 +KHCO 3 →K 2 SO 4 +H 2 O+CO 2 ↑ [0022] 7) 2KHS+K 2 CO 3 +4O 2 →2K 2 SO 4 +H 2 O+CO 2 ↑ [0023] The potassium hydroxide, potassium bicarbonate, or potassium carbonate may be purchased, but these compounds may be relatively expensive. Therefore, the invention preferably uses potassium hydroxide produced at the site of the hydrogen sulfide scrubber 10 from potash (potassium chloride or KCI), which is relatively inexpensive by comparison. The potash, which is stored in potash silo 30 , may be split in an electrochemical cell 40 by a process known to a person of ordinary skill in the art. The electrochemical cell 40 may use electrical energy to split KCI, in the presence of water, into KOH and HCI. These products are separated using membranes from the electrochemical cell 40 . The HCI from the electrochemical cell 40 is sold as a product or otherwise used elsewhere. The KOH from the electrochemical cell 40 may be used in the hydrogen sulfide scrubber 10 and in the oxidizer system 20 . Other conventional methods known to persons of ordinary skill in the art may be used for converting the potash to KOH. [0024] The conditions required to oxidize potassium hydrogen sulfide would include using high pressure air or oxygen, controlling operating parameters, including pH, feed rates, etc., and the use of catalysts, especially metals like cobalt, iron, etc., when required. It should be noted that for high pressure applications like sour gas processing, the solution from the hydrogen sulfide scrubber 10 may need to be introduced into a flash system (not shown) to reduce the pressure and remove entrained natural gas prior to the oxidation step 20 . [0025] The reaction product of the H 2 S reactions may include potassium thiosulfate, bisulfite, bisulfate, and/or sulfate. This reaction product may be concentrated and dried by any conventional method appreciated by a person of ordinary skill in the art to produce a high value fertilizer product. One conventional method of concentrating and drying employs an evaporator 60 that uses the energy from steam to remove water. The concentrated product is then dewatered by an appropriate dewatering device 70 , such as a vacuum filter, centrifuge, pressure filter, or the like. The concentrated and dried product may be combined with other ingredients, such as other fertilizers, pesticides, herbicides, micronutrients, minerals, etc. and combinations of these ingredients, to make a blended high value fertilizer. This combination of ingredients could be simply a blend or could be an improved fertilizer in the form of a pellet, granule, or other such particle made by known mechanical methods (not shown). [0026] A condenser 50 is used to separate and collect water from the outlet of evaporator 60 . The condensed water from condenser 50 is returned to the process for use. The condenser 50 reduces the amount of fresh make-up water required by the process. [0027] While the present invention has been illustrated by a description of various preferred embodiments and while these embodiments have been described in considerable detail in order to describe the best mode of practicing the invention, it is not the intention of applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the spirit and scope of the invention will readily appear to those skilled in the art. The invention itself should only be defined by the appended claims, wherein we claim:

A method of scrubbing hydrogen sulfide (H 2 S) from a gas stream employing a potassium-based sorbent to remove at least a portion of the H 2 S. This results in reaction products that are oxidized and converted into potassium-sulfur based fertilizers. The potassium based sorbent may be potassium hydroxide (KOH) made on site from potash. Hydrogen chloride (HCI) may be a byproduct when the sorbent is made from potash.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for performing resistance-type exercises and, more particularly, to a method and devices operable for changing the direction and magnitude of a resistive force in a cyclic manner multiple times during a single repetition of muscular contracture. 2. Prior Art Resistance exercise devices are well known in the art. Resistance exercises normally involve the contraction of a muscle against an opposing resistive force to move a portion of the body through a range of motion. The contraction is usually repeated to include a plurality of cycles (repetitions) of motion of the body portion through the range of motion, which range is determined by the degree of muscular contraction and extension achieved during a repetition. The resistive force may be provided by gravity, as with weight training (barbells, dumbbells, pull-up and pull-down stacks of weights, etc.), or by an elastic force such as springs, bungees and the like. Weight lifting is an exercise in which muscles are contracted against a resistance that is moved through a range of motion. The resistance is normally in the form of a weighted object that the user moves through either a flexion or extension of a body portion such as the arms or legs. In weight lifting, there are a number of exercises in which the user moves a weighted barbell in order to strengthen his or her upper body muscles. One example of such an exercise is a bench press in which the individual initially assumes a supine position atop a support bench. The weightlifter then uses his or her arms to lift the barbell from a position just above the lifter's chest to a higher vertical position where the lifter's arms are fully extended. This exercise is normally accomplished without any sideways movement (abduction or adduction) of the lifter's hands. This basic exercise can be modified by inclining the support bench (inclined press) or by starting with the bar substantially coplanar with the user's torso (pull overs). In the biomechanics of limb function, there one or more joints which contribute to the limbs functional motion. Each time the limb moves, motion takes place in one or more of these joints. Limb movement, such as movement of the arm, may include flexion, extension, abduction, adduction, circumduction, internal rotation, and external rotation. These movements are usually defined in relation to the body as a whole. Flexion of the shoulder is a forward movement of the arm. Extension, the reverse of this, is backward movement of the arm. Abduction is the movement of raising the arm laterally away from the body; adduction, the opposite of this, is then bringing the arm toward the side. Circumduction is a combination of all four of the above defined movements, so that the hand describes a circle. Internal rotation is a rotation of the arm about its long axis, so that the usual anterior surface is turned inward toward the body; external rotation is the opposite of this. All movements of limbs, for example, the arm relative to the shoulder, can be described by the terms used above. It will be appreciated by the artisan that most movements of a limb such as the arm are combinations of two or more of the above defined movements. A plurality of muscles cross each limb joint. Their function is to create motion, and thus the ability to do work with the limb. To perform a given task with precision, power, endurance, and coordination, most, if not all, of these muscles must be well conditioned. The function of each of these limb muscles depends on its relative position to the joint axis it crosses, the motion being attempted, and any external forces acting to resist or enhance motion of the limb. During limb motion, groups of muscles interact so that a desired movement can be accomplished. The interaction of muscles may take many different forms so that a muscle serves in a number of different capacities, depending on movement. At different times a muscle may function as a prime mover, antagonist, or a fixator or synergistically as a helper, a neutralizer or a stabilizer. For example, consider flexion of the arm. There are three major joints which contribute to elbow function: the ulnar-humeral, radio-humeral, and the radio-ulnar. The ulnar-humeral is responsible for flexion and extension while the radio-humeral and the radio-ulnar joints are responsible for supination and pronation. Flexion is movement in the anterior direction from the position of straight elbow, zero degrees to a fully bent position such as a curl. Extension is movement in a posterior direction from the fully bent position to the position of a straight elbow. A plurality of muscles effect motion at each limb joint. For example, in the elbow, these include the Biceps brachii, the Brachialis and the Triceps brachii. These muscles are continually active as their role changes in performing the complex activities of daily living. Each muscle spanning a limb joint has a unique function depending on the motion being attempted. It is generally conceded that in order to fully train and strengthen limb musculature, it is necessary to work the limb in all planes and extremes of motion to optimize neuromuscular balance and coordination. The types of limb exercise and/or exercise devices currently used in exercise programs generally include isometric, isotonic and isokinetic exercise. Isometrics is an exercise that is performed without any joint motion taking place. For example, pressing a hand against an immovable object such as a wall. When exercising a muscle group within a limb, strength can be improved only in the range of motion in which the limb is being exercised. Since in isometric exercises only one position and one angle can be used at one time, isometric exercise is time consuming if done correctly. Isotonic exercises are done against a movable resisting force. The resisting force is usually free weights. Isotonic exercises are probably the most common method for exercising both the upper and lower limbs as free weights are relatively inexpensive to acquire and readily available in gyms. A weight is held in the hand and moved in opposition to gravity. It is a functional advantage to be able to move a limb through a full range of motion, but because of the unidirectional nature of gravity, the body position must be continually changed for all muscles to be exercised. During a single repetition of isotonic weightlifting, the load remains constant but the amount of stress on the muscle varies. The most difficult point in the range is the initial few degrees with a movement to overcome inertia. As the upper extremity comes closer to the vertical position, work becomes easier due to improved leverage. This creates a noncyclic variability in the degree of muscle tension throughout the range of motion. Isotonic exercises can be performed on Nautilus and similar machines which achieve a more uniform resistance. A major disadvantage is that motion on these weightlifting machines is confined to a straight plane movement without deviation which does not replicate normal in-use movement of the limb. Isokinetic exercise involves a constant speed and a variable resistance. Isokinetic exercise machines are currently limited to movement of a limb in one straight plane. The advantage of exercising a limb with an isokinetic device is that the resistive force can be bi-directional within the single plane of movement. Current isokinetic machines do not permit motion of the limb through different planes during a single repetition. The particular muscle fibers involved in a contraction during a single repetition of resistive exercise depends upon the direction of the resistive force vector. If the resistive force vector is constant during a repetition, both directionally and in magnitude, as is the case with most prior art resistance exercise devices, only the muscles and portions of the muscle fibers within a muscle that are necessary to counter the resistive force will contract. Push-down/press-down (“PD2”) types of exercise devices, such as, for example, disclosed in U.S. patent application Publication No. US2002/0068666 by Bruccoleri, have been further improved to include flexible members attached to a horizontal resistance bar. The flexible members are adapted to be grasped by the hands. In operation, the direction of the resistive force vector changes during a repetition such that different muscles and different muscle fibers within a muscle are exercised during the repetition. While the direction of the resistive force vector at the point of contact with the exercisor's body (i.e., the hands) changes during a repetition using PD2-type devices, the magnitude of the resistive force does not exhibit oscillations during a repetition. The prior art pull-down/press-down resistance type of exercise devices, such as the device shown in FIG. 1 , enable the user to exercise a plurality of muscles during a repetition because the plane of motion of the limbs varies during a repetition and it enables a full range of motion of the limb through a repetition. A disadvantage for this type of device is that the vertical component of the resistive force F 2 ( FIG. 1 ) is constant during a repetition. It is desirable to provide a resistance exercise device wherein the direction of the resistive force oscillates in a cyclic fashion during a single repetition in order to increase the number of muscle fibers involved in the contraction over the number required when using a unidirectional device. There is also a need for a resistance exercise device wherein the magnitude of the resistive force oscillates over a plurality of cycles during a single repetition. SUMMARY It is an object of the present invention to provide a resistance exercise device operable for providing resistance to the movement of a muscle wherein the magnitude of the resistance oscillates for a plurality of cycles during contraction of the muscle that occurs while performing a single repetition. It is a further object of the present invention to provide a resistance exercise device operable for providing resistance to the movement of a muscle wherein the direction of the resistance oscillates for a plurality of cycles during contraction of the muscle while performing a single repetition. It is yet a further object of the present invention to provide a resistance exercise device operable for providing resistance to the movement of a muscle wherein both the direction and the magnitude of the resistance oscillates for a plurality of cycles during contraction of the muscle. The features of the invention believed to be novel are set forth with particularity in the appended claims. However the invention itself, both as to organization and method of operation, together with further objects and advantages thereof may be best understood by reference to the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing the movable portions of a pull-down/press-down type of exercise device in accordance with the prior art. FIG. 2 illustrates the resistive force vector provided by a prior art pull-down/press-down type of exercise device and the contractile force vectors applied by an exercisor that is required to overcome the resistive force vector. FIGS. 3 a–e are graphic representations illustrating examples of some of the possible oscillations in the magnitude F 2 and/or the direction Φ of the resistive force vector during a single repetition in accordance with the present method. The range of motion during the repetition begins on the left and terminates on the right. FIG. 4 is an elevational side view of an angular oscillation lead pulley in accordance with a preferred embodiment of an exercise device of the present invention. The angular oscillation lead pulley is used to cyclically change the direction of the resistive force vector F 2 a plurality of times during the performance of a single repetition of exercise. FIG. 5 is an elevational side view of an angular oscillation lead pulley in accordance with another preferred embodiment of an exercise device of the present invention. The angular oscillation lead pulley is used to cyclically change the direction of the resistive force vector F 2 nonuniformly and half as frequently during the performance of a single repetition of exercise than the lead pullet shown in FIG. 4 . FIG. 6 is an elevational view of a “bowtie” lead pulley in accordance with a second preferred embodiment of an exercise device of the present invention. The bowtie lead pulley simultaneously changes the leverage and thus the magnitude of F 2 and the angular displacement Φ of the resistive force vector in an oscillatory manner during the performance of a single repetition. FIG. 7 is a schematic diagram of a pull-down/press-down device in accordance with an embodiment of the present invention employing a cam-like lead pulley having a smaller circumference than the preceding cam-like pulley wherein the magnitude of the resistive force F 3 oscillates throughout the range of motion R during a repetition of the exercise. FIG. 8 is a graphical representation showing the change in the resistive force F 3 throughout the range of motion R for the embodiment of the invention illustrated in FIG. 7 . FIG. 9 is a front view of a lead pulley suitable for use with a PD2-type of exercise device to cause the direction of the resistive force to oscillate wherein the plane of the lead pulley is tilted with respect to its axis of rotation. DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIG. 1 , a pull-down/press-down (PD2) device in accordance with the prior art is indicated in perspective view at numeral 10 . For simplicity, only the moving parts of the PD2 device 10 are shown. In the device 10 , a weight stack 11 is in mechanical connection to a handgrip 12 by means of a cable 13 . The cable has a trailing end 13 ′ attached to the weight stack 11 and a leading end 13 ″ attached to the handgrip 12 . The cable 13 is supported by a rear pulley 14 and a lead pulley 15 . The term “lead pulley” as used in the discussion of PD2 devices to follow, refers to the pulley supporting the cable that is closest to the leading end 13 ″ of the cable 13 . The handgrip 12 may be a pair of handles connected to the free end 13 ″ of the cable by means of ropes or cables as shown, or it may comprise a bar, or similar grasping means. If the rear pulley 14 has a circular groove 16 , the resistive force F 1 (a directional arrow in FIG. 1 ) will be equal to the weight of the weight stack and oriented in the direction of the corresponding arrow. If the lead pulley 15 also has a circular groove 16 ′, the resistive force vector F 2 will be equal to F 1 in magnitude. If the sum of the projections of applied force vectors F 3 and F 3 ′ along the axis defined by F 2 is greater than resistive force F 2 , the weight stack 11 is lifted. When the applied forces F 3 and F 3 ′ are relaxed, the weight stack returns to its original position until either the applied force F 3 and F 3 ′ is reapplied, or it comes to rest on a support such as a floor (not shown) when the sum of the projections of F 3 and F 3 ′ along the axis defined by F 2 becomes less than F 2 . The lead pulley 15 may be modified ( FIGS. 4 and 5 ) such that when the lead pulley 15 turns as the cable 13 passes thereover, the lead pulley 15 changes the direction of F 2 to displace the vector F 2 through an angle Φ as shown in FIG. 2 . FIG. 2 illustrates the resistive force vector F 2 provided by a prior art pull-down/press-down type of exercise device and the applied force vectors F 3 and F 3 ′ applied by an exerciser that is required to provide a resultant force vector F 4 having a magnitude greater than the resistive force vector F 2 in a direction opposite to F 2 . As the direction of F 2 changes due to the displacement of the cable through an angle Φ, the projections of F 3 and F 3 ′, F 3 v and F 3 ′v, along the axis defined by the shifted direction of F 2 will also change. The applied forces F 3 and F 3 ′ must be changed by the exerciser in order to adapt to the fluctuating direction of F 2 . In order to adapt to the fluctuating (oscillating) direction of F 2 during a repetition, the exerciser will need to contract more different muscles than are required with a constant F 2 . The angle of displacement Φ and the magnitude of F 2 can be made to oscillate during a repetition. Some examples of the change in magnitude and direction of F 2 that are possible with particular lead pulley constructions, as will be discussed below, are shown in FIGS. 3 a–e . FIG. 3 a illustrates a sinusoidal fluctuation in either the magnitude or direction (or both) of F 2 that occur during a single repetition. FIG. 3 b shows sawtooth fluctuations. FIG. 3 c illustrates a train of narrow pulses whereas FIG. 3 d illustrates a square wave. FIG. 3 e shows a modified sawtooth fluctuation in the magnitude and/or direction of F 2 during a single repetition. Various means such as mechanical, hydraulic or pneumatic devices may be employed to vary the direction and/or magnitude of the resistive force F 2 in an oscillatory manner over a plurality of cycles during a repetition. Mechanical design of the lead pulley is a simple effective means for accomplishing such changes. FIG. 4 is an elevational view of an angular oscillation lead pulley 40 in accordance with a preferred embodiment of a PD2 exercise device of the present invention. The angular oscillation lead pulley 40 is used to cyclically change the direction of the resistive force vector F 2 a plurality of times during the performance of a single repetition of exercise. This is accomplished by forming the cable groove 16 in a cylindrical member 41 such that as the cylindrical member 41 turns about its axis of rotation A, the uppermost portion 42 of the groove 16 , which supports and guides the cable (the cable is not shown in FIG. 4 ), travels laterally in an oscillatory manner, returning to its starting position with every complete rotation of the cylindrical member 41 . The cylindrical member 41 has a diameter D. The pulleys 40 , 50 and 60 are all rotatably mounted and supported on the PD2 device by means of a cylindrical axle (not shown) affixed to the cylindrical member 41 coaxially with the axis of rotation A. FIG. 5 is an elevational side view of an angular oscillation lead pulley 50 in accordance with another preferred embodiment of an exercise device of the present invention. The angular oscillation lead pulley 50 is used to cyclically change the direction of the resistive force vector F 2 irregularly and half as frequently during the performance of a single repetition of exercise than the lead pulley 40 shown in FIG. 4 . The lead pulley designs presented above are suitable for providing a resistive force F 2 that oscillates in direction during the performance of an exercise repetition. FIG. 6 is an elevational view of a “bowtie” lead pulley in accordance with a second preferred embodiment of an exercise device of the present invention. The bowtie lead pulley 60 has a variable diameter D over the portion of the cylindrical member 41 traversed by the groove 16 and simultaneously changes the leverage and thus the magnitude of F 2 and the angular displacement Φ of the resistive force vector in an oscillatory manner during the performance of a single repetition. The frequency of oscillation of the magnitude and/or direction of the resistive force F 2 depends upon the particular lead pulley design and the speed at which the lead pulley rotates about the rotational axis A during the performance of a repetition. The number of cycles in the change of direction and/or magnitude in the resistive force F 2 that occurs during a repetition depends on the number of rotations the lead pulley makes during a repetition. It is obvious that for a lead pulley having the groove design illustrated in FIGS. 4–6 , a cylindrical member 41 having a small diameter D will provide more oscillations during a repetition than a lead pulley having a greater diameter D. Accordingly, in accordance with the goal of the present invention, it is desirable to select D such that the lead pulley rotates a plurality of times during a repetition. FIG. 7 is a schematic diagram of a pull-down/press-down device 70 in accordance with a double cam-pulley embodiment of the present invention. The device 70 employs a cam-like lead pulley 15 having a smaller circumference than the preceding cam-like pulley 71 wherein the magnitude of the resistive force F 3 oscillates throughout the range of motion R during a repetition of the exercise. FIG. 8 is a graphical representation showing the change in the resistive force F 3 throughout the range of motion R for the embodiment of the invention 70 illustrated in FIG. 7 . With continued reference to the PD2 device 70 of FIG. 7 , the lead pulley 15 may be cam-shaped and orthogonally mounted on its rotational axis 15 a as shown or it may be tilted on its rotational axis 15 a . If the plane of the lead pulley 15 is tilted with respect to its rotational axis 15 a , the resistive force F 3 , shown in FIG. 8 for an orthogonally mounted lead pulley, it will be appreciated by the artisan that the resistive force F 3 will further have an oscillating component in and out of the plane of the paper (not shown) that is orthogonal to a plane defined by the resistive force vectors F 1 and F 2 . FIG. 9 is a front view of a lead pulley suitable for use with a PD2-type of exercise device that is operable for causing the direction of a component of the resistive force to oscillate in and out of the plane of the paper ( FIG. 7 ). The plane P of the lead pulley 15 is tilted by an angle θ with respect to its axis of rotation A. In addition to being tilted, the lead pulley 15 may also be cam-shaped to provide oscillatory changes in both the direction and the magnitude of the resistive force during a single repetition. The method for performing an exercise using the devices described above requires that the muscle(s) being exercised adapt to a fluctuating resistive force a plurality of times during a repetition. The adaptation requirement provides means for strengthening more cooperating muscles during a repetition than is possible when countering a constant resistive force. The method and device of the present invention enables the noncontiguous innervation of muscles during a repetition. It is noted that the muscles involved in a repetition “learn” how to adapt if the cyclic variations in the resistive force occur synchronously during each repetition. It is, therefore, desirable to design the exercise device such that the rotational orientation of the lead pulley at the beginning of each repetition is different than the orientation of the lead pulley at the beginning of the previous repetition. While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. For example, as mentioned hereinabove, a variety of means such as pneumatic or hydraulic pumps and programmable controllers therefore, as well as specially designed lead pulleys as described hereinabove can be employed to cause the resistive force to oscillate in magnitude and/or direction during a repetition. With the use of programmable computer means, the waveform and/or the frequency of oscillations in the resistive force can also be made to fluctuate either in a predictable pattern or a random fashion during a repetition. Further, although the invention has been presented using a PD2 device as an example of a device embodying the principles of the method, other resistance-type exercise devices employing an oscillating resistive force during a repetition are contemplated. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

A method for exercising one or more muscles of the body wherein one or more muscle(s) are contracted to move a limb through a range of motion in opposition to an oscillating resistive force. In accordance with the method, during a muscular contraction, the direction and/or the magnitude of the resistive force changes in an oscillatory fashion. The oscillations in the magnitude and/or the direction of the resistive force include a plurality of cycles during a single repetition of muscular contraction. The waveform and frequency of the oscillations may vary during a repetition or remain constant. Embodiments of devices providing an oscillatory resistive force are presented. The embodiments provide means for enabling an exerciser to perform resistance-type exercises in accordance with the method.

This application is a division, of application Ser. No. 07/712,261, filed Jun. 7, 1991, now abandoned. BACKGROUND OF THE INVENTION The formation of ceramic shapes from ceramic powders normally involves pressing or extrusion of a mixture of the ceramic powders and various additives so that a dense cohesive structure is formed which is then heated in a kiln (fired) to destroy any residual organic components and to promote the sintering of the inorganic powder so that further densification and strengthening results. It is essential to produce a final structure with minimal free voids between ceramic powder particles in order to achieve the highest possible density and tensile strengths of the green and sintered bodies. Although pressure of formation plays an important role in densification, pressing under high loads (>100 MPa) will not convert ceramic powder alone into a firm body. The shape formed in this manner would simply crumble when ejected from the die or mold. Organic binders are used to overcome these problems. Organic binders provide lubricity to facilitate the compression of the green structure into a high density form, and adhesion so that the "green", unfired, body holds together. Upon firing and the onset of sintering, the organic binder is no longer required. Complete pyrolysis of the organic material present, so that there are no residues which might adversely affect the sintering process, occurs in the early stages of the firing process. In practice, the ceramic powder, e.g., alumina, is dispersed in a liquid carrier (water or organic) with the aid of chemical dispersants and mechanical action. A dispersant is necessary in order to make a stable, liquid dispersion at high solids. Although a variety of materials may be used for this function, frequently a low molecular weight poly(acrylic acid) as its sodium or ammonium salt is used. The level of use of this dispersant is usually in the range of 0.05-0.5% by weight based on alumina. Other dispersants that have been used are poly(methacrylic acid) salts and lignosulfonic acid salts. An organic polymeric binder and other functional materials such as lubricants and sintering aids are then added. The resulting slurry or slip is spray dried to yield a free-flowing powder consisting of spherical agglomerates (granules) of about 50-200 micrometer diameter. Approximately 2-8% binder (based on the dry weight of powder) is commonly used. The formulated powder can next be pressed to the desired shape in a suitable die from which it is then ejected. The viscosity of the complete slurry must be suitable for necessary handling and spray drying. Although spray dry equipment and running conditions may be adjusted to handle a variety of viscosities, larger particles will result from higher viscosity slurries. The resultant large particles may result in larger interstices between particles and hence a lower strength. The binder may contribute to viscosity of the continuous phase of the slurry by virtue of its molecular weight, solubility, conformation in solution, and possible incompatibility with the combination of powder and dispersant. The spray-dried blend of powder and binder must be free flowing so that it can completely fill dies. The resulting compacted part must be smoothly ejected, be as dense as possible, and not suffer significant dimensional change from that of the die. Chemical additives have a major effect on the desired lubricity. Polyethylene oxides and fatty acid derivatives promote lubrication (the former may also behave as a binder). During dry pressing, the granules are deformed and the binder flows to fill available space, thus increasing density. The glass transition temperature (Tg) of the polymer can have a strong effect in this step. Polymers with too high a glass transition temperature will not flow and as a result cohesion of the pressed part does not occur. Under these conditions, the compressed powder will undergo stress relaxation in the form of expansion on release from the die. This phenomenon is referred to as "springback" and is undesirable from the standpoint of dimensional accuracy as well as density and strength. For this reason, plasticizers are used with higher Tg polymers. Frequently, mixtures of polymers having greatly different physical properties are used as binders. For example, a plastic material such as polyethylene oxide may be blended with a film-forming binder such as polyvinyl alcohol to give an effective ceramic binder. The polymer binders currently used for the binding of ceramic powders have, as a class, not been specifically synthesized for optimal densification and green strength of ceramic forms. Rather, they are commercially available materials, with other principal uses, which have been adapted for use in ceramic manufacture and include such materials as cellulose ethers, polysaccharides, polyacrylic latexes, poly(2-ethyl-2-oxazoline), poly(ethylene oxide), poly(vinyl alcohol), poly(vinyl butyral), and wax. Of these, poly(2-ethyl-2-oxazoline), poly(ethylene oxide), poly(vinyl alcohol), and wax are used in the spray drying process. The principal function of the binder is to hold the compacted form together after pressing. The method utilized for determination of suitable "green strength" is the diametral compression strength or DCS of a cylindrical section across its diameter. DCS is actually a measure of tensile strength. The unit of measurement of the pressure tolerance is the megapascal (MPa). Typical values for DCS of "green" parts are in the range 0.3-3.0 MPa. It should be recognized that the strength of the green part is largely a function of the state of the binder phase. If the binder does not flow (as in the case of too high a Tg), or if it is a liquid (as in the case of too low a Tg), a weak non-coherent green part will result. The binder must coat/wet the ceramic powder, flow easily at the pressure and temperature of the die, and be cohesive at the test temperature. Binders must be cost effective and highly soluble in water or suitable organic solvents, such as alcohols, toluene, or xylene. Oxide ceramics absorb atmospheric moisture. Since water is known to plasticize alumina and many hydrophilic organics, alumina green bodies will lose strength when exposed to humid conditions (R. A. Dihilia et al, Advan. Ceram. 9, 38-46 (1984); C. E. Scott et al, Amer. Ceram. Soc. Bull. 61 (5), 579-581 (1982). Binders which would have less sensitivity to moisture, without loss of cohesive strength, would clearly be advantageous. In summary, a preferred binder for ceramic powders would be soluble in water and a wide range of organic solvents. This ideal binder would be suitable for all ceramic powders and form easily spray-dried mixtures, be compatible with all dispersants and even function itself as a dispersant. It would allow pressing to maximum density with minimal pressure and eject easily from the die. Springback would not occur. It would not require a separate plasticizer or be sensitive to atmospheric moisture. The ideal binder would not leave any deleterious residues during the burn out and firing. Although poly(ethylene oxides) or poly(ethylene glycols) are commonly used as a binder for ceramics in industry, they have some deficiencies. The use of poly(ethylene oxides) is generally limited to aqueous processes where they produce slurries of high viscosity. They have solubility only in methanol and methylene chloride at ambient temperature. These two solvents are very low boiling and toxic. Poly(2-ethyl-2-oxazoline) is more expensive than the polyethylene glycol-type resins. It has as an advantage a low molecular weight which gives rise to low aqueous system viscosities. A deficiency of this resin is its high Tg (70 C) which is too high for normal processing and must therefore be admixed with a plasticizer (PEG 400). This polyether however renders poly(2-ethyl-2-oxazoline) formulations hygroscopic. Poly(vinyl alcohol) also requires plasticizing. The various acrylic latex type binders produce very desirable low viscosity slips. The dried powders, however, are very hard and do not press well. Aluminum oxide (alumina) is by far the most widely used powder in technical ceramics. Zirconium oxide (zirconia), beryllium oxide (beryllia), and other oxides are used in special applications as are the non-oxides, silicon carbide and silicon nitride. SUMMARY OF THE INVENTION The present invention comprises a ceramic binder composition comprising block copolymers of alkylene oxides, such as ethylene oxide and propylene oxide, which are water-soluble and are solids at room temperature yet plastic enough to deform during pressing, which are further formulated with water-soluble, film-forming polymers such as poly(N-vinylpyrrolidinone) and poly(vinyl alcohol) and their copolymers. These polymer blends are useful as binders for alumina powders for use in ceramics. In aqueous media, their lower viscosities enable facile spray drying. The dried alumina powders may be compressed under relatively low pressure into high density forms with superior unfired strengths. They are only moderately affected by humidity, are readily ejected from the die and burn off cleanly in the initial stages of firing. The preferred binders consist of ethylene oxide/propylene oxide block copolymers containing 70-80 weight % ethylene oxide and bearing terminal ethylene oxide blocks with molecular weights in the 5,000 to 20,000 range which are further formulated with film-forming polymers such as homopolymers or copolymers of N-vinylpyrrolidinone. DETAILED DESCRIPTION OF THE INVENTION Examples of the block copolymer useful in the present invention are the simple A-B-A copoly(ethylene oxide-propylene oxide) condensates and copoly(ethylene oxide-propylene oxide) ether-linked to (1,2-ethandiyldinitrilo) tetrakis[propanol] (4:1) (CAS 11111-34-5). These copolymers are produced by a number of chemical companies including BASF, GAF, Mazer Chemicals and Nalco Chemical Co. among others. The molecular weights of the ethylene oxide-propylene oxide block copolymers which are most effective green strength binders lie in the range of 5,000 to 20,000. Optimal performance of these condensates is achieved by further formulation with various additives. The hydrophilic ether block copolymers are surface active and lead to foaming in slip compositions. This is undesirable in that it interferes with pumping and spray drying of the slurry. To overcome this difficulty, a suitable antifoaming agent is employed. An example of such a defoamer is 2,4,7,9-tetramethyl-5-decyn-4,7-diol (marketed by Air Products Corporation as Surfynol 104). This material will not interfere with the compaction, green strength, springback, or sintering of the ceramic part. Other suitable defoamers include hydrophobic, low molecular weight (<10,000) ethylene oxide/propylene oxide block coplymers containing about 80-90 weight % propylene oxide; linear aliphatic alcohols such as 1-heptanol, 1-octanol and 1-decanol (however, 1-dodecanol is not suitable); and poly(dimethylsiloxanes) which are common active ingredients of antifoams. Other materials which do not interfere in the above factors may also be used such as hydrophobic block copolymers of ethylene oxide/propylene oxide. Antifoam agents may be incorporated at a level of less than 5%, preferably 0.5-2.5% of the total dry weight binder composition, and post preferably 1.0-2.0% total dry weight binder composition. Although the examples of this invention describe block copolymers of ethylene oxide and propylene oxide, this does not preclude the use of hydrophobic center blocks other than propylene oxide. Thus, the central block may be, for example, derived from polyether producing monomers such as 1-butene oxide, 2-butene oxide, styrene oxide, tetrahydrofuran and dimethyl oxetane. The center block may be composed of hydroxy terminated low molecular weight polymers such as hydroxy terminated polybutadiene or hydroxy terminated polyesters. Still further variations contemplated in this invention are low molecular weight center blocks wherein the terminal groups have the capacity to react with ethylene oxide such as amine terminated polyamides, carboxyl terminated polyamides, carboxyl terminated polyesters, hydroxy terminated polyurethanes, amine terminated polyurethanes, amine terminated polyurea resins, amine terminated poly propylene oxide resins (Jeffamines), and similar materials. Performance of the binder resin can be substantially improved through the addition of film-forming polymers such as poly (N-vinylpyrrolidinone) (PVP) (GAF or BASF Corporations), or poly(vinyl alcohol). The addition of 20-60% PVP basis the dry weight of the formulated binder produces significant increases in green DCS and with only modest decreases in density. The present invention can be more readily understood by the following representative examples using the test methods specified. TEST METHODS Preparation Of Air-Dried Powders. Powdered mixtures of alumina and binder were prepared by dispersion, air drying, crushing and sieving. For example, 100 g of alumina (Alcoa A16SG) was added slowly to a rapidly-stirred solution of 0.20 g of a 31.7% aqueous solution of ammonium polyacrylate in 40.0 g of deionized water with vigorous mixing (cage mixer). The concentrated binder solution was then added and stirring continued for 20 minutes. This finished slurry was then poured into a flat aluminum tray and allowed to air dry for 24 hours at 50% relative humidity and 22° C. The dried material was then crushed in a mortar and pestle and sieved. The entire -40 fraction was retained for testing. Preparation Of Spray-Dried Powders Formulated alumina-binder slurries were also dried using a Yamato Model DL-41 laboratory spray dryer. These slurries were ball milled overnight and screened through a 100-mesh wire before drying. For routine work, the slurry was fed at 35 ml/min, with atomizing air set at 33 L/min. Drying air flow was set at 0.6 m 3 /min and drying air temperature at 250° C. These settings were found to give an acceptably dry powder. Typically, powders of about 130-150 μm diameter (weight average) were produced. The powder was stored under controlled humidity conditions for three days before pressing. Typically particles larger than 60 mesh and smaller than 325 mesh were not used. This was done to approximate the particle sizes produced in a commercial scale spray dryer. Controlled humidity was produced in desiccators containing either anhydrous calcium sulfate (Drierite) or various saturated aqueous salt solutions. Preparation Of Ceramic Green Bodies. Test pieces were made by pressing 20.0 g of sieved powder in a cylindrical hardened tool steel die (interior diameter 28.57 mm) on a Carver Model-M 25 ton laboratory press equipped with time and pressure release controls. Maximum pressure was typically 5,000 to 25,000 psi. Press closure speed was usually set at 8.4 mm/sec. Test pieces were ejected from the die and stored at controlled relative humidity for at least 24 hours before testing. Testing Of Green Ceramic Bodies. Densities were determined by measuring the height, diameter and weight of the test cylinders. Height was an average of six determinations and diameter of three determinations. Weight was measured to the nearest 0.0001 g. Densities were corrected for binder content. Strength was measured as diametral compression strength (DCS) on a Hinde and Dauch Crush Tester in a controlled atmosphere (22° C., 50% relative humidity). DCS is actually a tensile measurement in which the test piece is placed on edge and split along its diameter. Forming and testing of green ceramics are vulnerable to environmental variations. For this reason, it is imperative to run internal controls. EXAMPLE 1 The effects of molecular weight and/or the ethylene oxide content of the various polyethers studied is demonstrated in this set of experiments. The materials used were alumina A16SG from Alcoa Corporation, poly (ethylene oxide) resins from Union Carbide, and several Tetronic resins from BASF Corporation. The alumina was treated with 5% binder, air-dried, equilibrated at 0% relative humidity at room temperature, pressed at 16,000 psi, and tested according to the methods described above. The densities recorded were corrected for the binder content. __________________________________________________________________________COMPARISON OF VARIOUS POLYETHERS ON GREEN PROPERTIES PROPYLENE GREEN CERAMIC PROPERTIES POLYETHER OXIDE MOL. WT. × DENSITY DCSPOLYETHER TYPE WT. % 0.001 g/cc MPa__________________________________________________________________________A PEO 0 1.0 2.241 0.278B PEO 0 8.0 2.181 0.308C PEO-M 0 20 2.188 0.544D PEO 0 300 2.153 0.599E EO-PO-EDA-PO-EO 60 6.7 2.230 0.264F EO-PO-EDA-PO-EO 30 12.2 2.232 0.749G EO-PO-EDA-PO-EO 20 25 2.202 0.700H PO-EO-EDA-EO-PO 20 18.7 2.230 0.535__________________________________________________________________________ PEO = polyethylene oxide; PEOM = polyethylene oxide crosslinked with 2,2[(1methylethylidene)bis(4,1 phenyleneoxymethylene)]bisoxirane; EOPO-EDA-PO-EO = copoly(ethylene oxidepropylene oxide) etherlinked to (1,2ethandiyldinitrilo)tetrakis[propanol] (4:1) (CAS 1111134-5). These data show the superior compaction and green strength properties of EO-PO block copolymers compared to polyethylene oxides of comparable molecular weight. EXAMPLE 2 These experiments demonstrate the effect of added poly(N-vinylpyrrolidinone) on the performance of an EO/PO block copolymer (polyether F in Example 1). As in Example 1, the alumina used was A16SG from Alcoa Corporation. Poly(N-vinylpyrrolidinone) is available commercially from BASF Corporation and from GAF Chemicals. The two PVP resins used in the study were K15 (molecular weight of 10,000) and K30 (molecular weight of 40,000). The powder samples were prepared by spray drying at 250° C., pressed at 16,000 psi, and tested as described under TEST METHODS. Powders and test pieces were equilibrated at 0% R.H. ______________________________________EFFECT OF PVP ON PERFORMANCE OF EO/POSAMPLE F(All formulations contain 2%, by weight based on EO/OPpolymer, of antifoam.) GREEN CERAMIC PROPERTIES WT. DENSITYPVP TYPE %- PVP g/cc DCS (MPa)______________________________________F-1 None (control) 0.0 2.284 0.612F-2 PVP-K15 20.0 2.263 1.270F-3 " 40.0 2.255 1.980F-4 " 60.0 2.248 2.773F-5 " 80.0 2.231 1.768F-6 PVP-K30 20.0 2.267 1.804F-7 " 40.0 2.227 1.390F-8 " 60.0 2.172 0.713F-9 " 80.0 2.125 0.262______________________________________ EXAMPLE 3 This example determined the effect of compacting pressures on A16SG alumina treated with 5% formulated binders. The powders were prepared and pressed as in Example 2. These comparisons demonstrate the weakness of PVP as a binder and the superior performance of blends of PVP with an EO/PO block copolymer. The absolute values of strength and density are lower than those shown in Example 2. This shows the susceptibility of testing of green ceramics to environmental variations and the need to run controls. ______________________________________BINDER COMPONENT F-10______________________________________ Polyether F 49.0% (Example 1) Surfynol 104 1.0% PVP-K15 50.0%______________________________________ ______________________________________PERFORMANCE DATA GREEN CERAMIC PROPERTIES PRESSURE DENSITY DCSBINDER psi × 0.001 g/cc MPa______________________________________F-6 12 2.231 1.060F-10 " 2.167 0.759F1 " 2.257 0.604PVP-K15 " 2.108 0.169C " 2.182 0.252F-6 20 2.275 1.363F-10 " 2.237 1.213F-1 " 2.310 0.885PVP-K15 " 2.194 0.362C " 2.227 0.416F-6 24 2.284 1.049F-10 " 2.253 1.162Fl " 2.296 0.593PVP-K15 " 2.215 0.389C " 2.226 0.416______________________________________ EXAMPLE 4 This example demonstrated the effect of relative humidity on the physical properties of the green parts. Powders and compacts were prepared as in Example 3, pressing at 16,000 psi. Powders and compacts were equilibrated at 0%, 20% or 52% relative humidity. Increasing humidity results in higher densities which in these experiments leads to higher green strengths. ______________________________________EFFECT OF RELATIVE HUMIDITY ON GREENPROPERTIESRELATIVE GREEN CERAMIC PROPERTIES HUMIDITY DENSITY DCSBINDER % g/c MPa______________________________________F-6 0 2.226 0.479" 20 2.224 0.440" 52 2.274 0.666F-10 0 2.190 0.636" 20 2.218 0.611" 52 2.279 0.888______________________________________ EXAMPLE 5 This example demonstrates the interrelationship between the effects of relative humidity and compression pressure on the physical properties of the green parts. The samples were prepared and tested according to the methods outlined in Example 1. ______________________________________EFFECT OF R.H. AND COMPACTING PRESSUREON GREEN PROPERTIES GREEN PRES- CERAMIC PROPERTIES SURE DENSITY DCSBINDER R.H. % psi × 0.001 g/cc MPa______________________________________F-6 0 8 2.2405 0.4162" " 16 2.3476 0.7380" " 24 2.3891 0.8619" 20 8 2.2762 0.4726" " 16 2.3661 0.7518" " 24 2.4161 0.9211" 52 8 2.3164 0.5065" " 16 2.4038 0.6621" " 24 2.4555 1.1905C 0 8 2.2376 0.2066" " 16 2.3452 0.4641" " 24 -- --" 20 8 2.4149 0.2105" " 16 2.3606 0.4142" " 24 2.4181 0.5815" 52 8 2.2929 0.1805" " 16 2.3999 0.3457" " 24 -- --______________________________________ EXAMPLE 6 To demonstrate the effects of ethylene oxide content on compaction and strength properties of the polyethers alone and in combination with a film-forming reinforcing polymer, several additional materials were investigated. These binders were applied at 5% on A152SG alumina (Alcoa) and spray dried at 250° C. as explained under TEST METHODS. The powders were equilibrated at 20% R.H. before pressing and test pieces were equilibrated at 20% R.H. before testing. These materials are described in the following tables: ______________________________________ wt. %Polyether Polyether Type PO M.W. × 0.001______________________________________I EO-PO-EO 60 4.7J EO-PO-EDA-PO-EO 60 10.5K PO-EO-PO 20 7.0L PO-EO-EDA-EO-PO 20 10.2M EO-PO-sorbitol-PO-EO 90 9.9N EO-PO-sorbitol-PO-EO 80 10.8O EO-PO-sorbitol-PO-EO 70 11.7P EO-PO-EO 90 4.4Q EO-PO-EO 80 4.8R EO-PO-EO 70 5.2______________________________________ ______________________________________BINDER COMPOSITIONS wt. % wt. % wt. %Binder Polyether Polyether Surtynol 104 PVP K-30______________________________________A-1 A 98.0 2.0 0A-2 A 78.4 1.6 20.0B-1 B 98.0 2.0 0B-2 B 78.4 1.6 20.0I-1 I 98.0 2.0 0I-2 I 78.4 1.6 20.0J-1 J 98.0 2.0 0J-2 J 78.4 1.6 20.0K-1 K 98.0 2.0 0K-2 K 78.4 1.6 20.0L-1 L 98.0 2.0 0L-2 L 78.4 1.6 20.0M-1 M 98.0 2.0 0M-2 M 78.4 1.6 20.0N-1 N 98.0 2.0 0N-2 N 78.4 1.6 20.0O-1 0 98.0 2.0 0O-2 0 78.4 1.6 20.0P-1 P 98.0 2.0 0P-2 P 78.4 1.6 20.0Q-1 Q 98.0 2.0 0Q-2 Q 78.4 1.6 20.0R-1 R 98.0 2.0 0R-2 R 78.4 1.6 20.0______________________________________ ______________________________________PERFORMANCE DATA: Green Ceramic Properties Pressure GreenBinder (psi × 0.001) Density (g/cc) DCS(MPa)______________________________________A-1 10 2.367 0.082" 15 2.408 0.062" 20 2.424 0.049A-2 10 2.358 0.177" 15 2.378 0.151" 20 2.419 0.252B-1 10 2.303 0.173" 15 2.343 0.201" 20 2.372 0.130B-2 10 2.288 0.406" 15 2.332 0.544" 20 2.382 0.373I-1 10 2.335 0.029" 15 2.382 0.035" 20 2.409 0.073I-2 10 2.381 0.163" 15 2.379 0.176" 20 2.407 0.110J-1 10 2.381 0.058" 15 2.406 0.083" 20 2.429 0.073J-2 10 2.350 0.228" 15 2.390 0.318" 20 2.422 0.301K-1 10 2.346 0.191" 15 2.385 0.290" 20 2.413 0.251K-2 10 2.300 0.364" 15 2.348 0.364" 20 2.384 0.303L-1 10 2.381 0.163" 15 2.411 0.355" 20 2.428 0.371L-2 10 2.325 0.531" 15 2.372 0.653" 20 2.407 0.532M-1 10 2.350 0.004" 15 2.380 0.004" 20 2.402 0.004M-2 10 2.329 0.021" 15 2.364 0.018" 20 2.404 0.024N-1 10 2.330 0.004" 15 2.379 0.004" 20 2.391 0.004N-2 10 2.319 0.016" 15 2.362 0.063" 20 2.386 0.051O-1 10 2.372 0.004" 15 2.401 0.004" 20 2.423 0.004O-2 10 2.350 0.060" 15 2.385 0.053" 20 2.410 0.076P-1 10 2.340 0.004" 15 2.377 0.004" 20 2.425 0.004P-2 10 2.329 0.031" 15 2.365 0.008" 20 2.391 0.013Q-1 10 2.337 0.004" 15 2.367 0.004" 20 2.384 0.004Q-2 10 2.318 0.057" 15 2.358 0.042" 20 2.385 0.061R-1 10 2.361 0.004" 15 2.384 0.004" 20 2.411 0.004R-2 10 2.331 0.067" 15 2.363 0.079" 20 2.386 0.053______________________________________ These data show that polyethers containing no propylene oxide and that those composed mainly of propylene oxide (>60%) are inferior to those containing the preferred range (20-30%). Indeed, those containing significant amounts of propylene oxide yield extremely weak compacts. Although the performance of all of the polyethers is improved by the reinforcing polymer, the differences between the preferred block copolymers and copolymers lying outside the preferred composition range are still apparent. EXAMPLE 7 To demonstrate that film-forming polymers in general can be used in conjunction with the preferred EO-PO block copolymers, a number of the former were formulated with Polyether F. All of the following binder formulas consist of 78.4% Polyether F, 1.6% Surfynol 104 and 20.0% film-forming polymer as set out in the following table. The formulated binders were applied at 5% (based on A152SG alumina) and spray dried at 250° C. as in Example 2. Powders and test cylinders were equilibrated at 20% R.H. ______________________________________COMPO-SITION FILM-FORMER TRADE-NAME______________________________________F-11 polyvinyl alcohol, 87-89% Airvol 205.sup.(1) hydrolyzed, M.W. 31-50 × 10.sup.3F-12 polyvinyl alcohol, 87-89% Airvol 523.sup.(1) hydrolyzed, M.W. 85-146 × 10.sup.3F-13 copoly(vinyl acetate-N- PVP/VA S-630.sup.(2) vinylpyrrolidinone) (70:30)F-14 copoly(vinyl acetate-N- PVP/VA E-735.sup.(2) vinylpyrrolidinone) (60:40)F-15 copoly(styrene-N- Polectron 430.sup.(2) vinylpyroolidinone)______________________________________ .sup.(1) Air Products and Chemicals Corp.; .sup.(2) GAF Chemicals Corp. These data demonstrate excellent performance of the preferred PO-EO block copolymers when formulated with various film-forming synthetic polymers. ______________________________________PERFORMANCE DATA: Green Ceramic Properties Pressure GreenBinder (psi × 0.001) Density (g/cc) DCS(MPa)______________________________________F-6 5 2.221 0.367" 10 2.324 0.628" 15 2.384 0.852" 20 2.414 0.920" 25 2.432 0.973F-11 5 2.197 0.300" 10 2.313 0.556" 15 2.368 0.767" 20 2.411 0.926" 25 2.431 0.953F-12 5 2.119 0.192" 10 2.257 0.420" 25 2.398 0.828F-13 5 2.219 0.315" 10 2.331 0.607" 15 2.384 0.752" 20 2.417 0.879" 25 2.439 0.925F-14 5 2.238 0.268" 10 2.344 0.532" 15 2.389 0.663" 20 2.424 0.770" 25 2.444 0.823F-15 5 2.209 0.281" 10 2.334 0.647" 15 2.386 0.768" 20 2.422 0.875" 25 2.443 0.972______________________________________

The present invention comprises block copolymers of alkylene oxides, such as ethylene oxide and propylene oxide, which are further formulated with additional polymers such as poly(N-vinylpyrrolidinone), poly (vinyl alcohol), and certain low foam additives. These polymers are useful for the coating of alumina powders for use in ceramics. In aqueous media, their lower viscosities enable facile spray drying of the coated alumina powders. The coated alumina powders may be compressed under relatively low pressure into high density forms with superior unfired compressive strengths (green strength), they are surprisingly insensitive to relative humidity, are readily ejected from the mold, and finally do not have a deleterious effect upon the ultimate high temperature sintering of the formed bodies.

This application is a Divisional patent application under 37 C.F.R. § 1.53(b), of pending prior application Ser. No. 09/165,772, filed on Oct. 2, 1998, which claims benefit of the earlier filing date of U.S. provisional application No. 60/060,858, filed on Oct. 2, 1997. FIELD OF THE INVENTION The present invention relates, in general, to automotive fuel leak detection methods and systems and, in particular, to a temperature correction approach to automotive evaporative fuel leak detection. BACKGROUND OF THE INVENTION Automotive leak detection systems can use either positive or negative pressure differentials, relative to atmosphere, to check for a leak. Pressure change over a given period of time is monitored and correction is made for pressure changes resulting from gasoline fuel vapor. It has been established that the ability of a leak detection system to successfully indicate a small leak in a large volume is directly dependent on the stability or conditioning of the tank and its contents. Reliable leak detection can be achieved only when the system is stable. The following conditions are required: a) Uniform pressure throughout the system being leak-checked; b) No fuel movement in the gas tank (which may results in pressure fluctuations); and c) No change in volume resulting from flexure of the gas tank or other factors. Conditions a), b), and c) can be stabilized by holding the system being leak-checked at a fixed pressure level for a sufficient period of time and measuring the decay in pressure from this level in order to detect a leak and establish its size. SUMMARY OF THE INVENTION The method and sensor or subsystem according to the present invention provided a solution to the problems outlined below. In particular, an embodiment of one aspect of the present invention provides a method for making temperature-compensated pressure readings in an automotive evaporative leak detection system having a tank with a vapor pressure having a value that is known at a first point in time. According to this method, a first temperature of the vapor is measured at substantially the first point in time and is again measured at a second point in time. Then a temperature-compensated pressure is computed based on the pressure at the first point in time and the two temperature measurements. According to another aspect of the present invention, the resulting temperature-compensated pressure can be compared with a pressure measured at the second point in time to provide a basis for inferring the existence of a leak. An embodiment of another aspect of the present invention is a sensor subsystem for use in an automotive evaporative leak detection system in order to compensate for the effects on pressure measurement of changes in the temperature of the fuel tank vapor. The sensor subsystem includes a pressure sensor in fluid communication with the fuel tank vapor, a temperature sensor in thermal contact with the fuel tank vapor, a processor in electrical communication with the pressure sensor and with the temperature sensor and logic implemented by the processor for computing a temperature-compensated pressure based on pressure and temperature measurements made by the pressure and temperature sensors. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows, in schematic form, an automotive evaporative leak detection system in the context of an automotive fuel system, the automotive leak detection system including an embodiment of a temperature correction sensor or subsystem according to the present invention. FIG. 2 shows, in flowchart form, an embodiment of a method for temperature correction, according to the present invention, in an automotive evaporative leak detection system. DETAILED DESCRIPTION We have discovered that, in addition to items a), b), and c) set forth in the Background section above, another condition that affects the stability of fuel tank contents and the accuracy of a leak detection system is thermal upset of the vapor in the tank. If the temperature of the vapor in the gas tank above the fuel is stabilized (i.e., does not undergo a change), a more reliable leak detection test can be conducted. Changes in gas tank vapor temperature prove less easy to stabilize than pressure. A vehicle can, for example, be refueled with warmer than ambient fuel. A vacuum leak test performed after refueling under this condition would falsely indicate the existence of a leak. The cool air in the gas tank would be heated by incoming fuel and cause the vacuum level to decay, making it appear as though there were a diminution of mass in the tank. A leak is likely to be falsely detected any time heat is added to the fuel tank. If system pressure were elevated in order to check for a leak under a positive pressure leak test, and a pressure decay were then measured as an indicia of leakage, the measured leakage would be reduced because the vapor pressure would be higher than it otherwise would. Moreover, measured pressure would also decline as the vapor eventually cools back down to ambient pressure. A long stabilization period would be necessary to reach the stable conditions required for an accurate leak detection test. The need for a long stabilization period as a precondition to an accurate leak detection test result would be commercially disadvantageous. A disadvantageously long stabilization period can be compensated for and eliminated, according to the present invention, by conducting the leak detection test with appropriate temperature compensation even before the temperature of the vapor in the gas tank has stabilized. More particularly, a detection approach according to the present invention uses a sensor or sensor subsystem that is able to either: 1) Provide information on the rate of change of temperature as well as tank vapor pressure level, and correct or compensate for the change in temperature relative to an earlier-measured temperature reference; or 2) Provide tank pressure level information corrected (e.g., within the sensor to a constant temperature reference), the result being available for comparison with other measured pressure to conduct a leak-detection test. In order to obtain the data required for option 1), two separate values-must be determined (tank temperature rate of change and tank pressure) to carry out the leak detection test. These values can be obtained by two separate sensors in the tank, or a single sensor configured to provide both values. Alternatively, if tank pressure is to be corrected in accordance with option 2), then a single value is required. This single value can be obtained by a new “Cp” sensor (compensated or corrected pressure sensor or sensor subsystem) configured to provide a corrected pressure. To obtain this corrected pressure, P c , the reasonable assumption is made that the vapor in the tank obeys the ideal gas law, or: PV=nRT where: P=pressure; V=volume; n=mass; R=gas constant; and T=temperature. This expression demonstrates that the pressure of the vapor trapped in the tank will increase as the vapor warms, and decrease as it cools. This decay can be misinterpreted as leakage. The Cp sensor or sensor subsystem, according to the present invention, cancels the effect of a temperature change in the constant volume gas tank. To effectuate such cancellation, the pressure and temperature are measured at two points in time. Assuming zero or very small changes in n, given that the system is sealed, the ideal gas law can be expressed as: P 1 V 1 /RT 1 =P 2 V 2 /RT 2 Since volume, V, and gas constant, R, are reasonably assumed to be constant, this expression can be rewritten as: P 2 =P 1 ( T 2 /T 1 ). This relation implies that pressure will increase from P 1 to P 2 if the temperature increases from T 1 to T 2 in the sealed system. To express this temperature-compensated or -corrected pressure, the final output, P c , of the Cp sensor or sensor subsystem will be: P c =P 1 −( P 2 −P 1 ) where P c is the corrected pressure output. Substituting for P 2 , we obtain: P c =P 1 −( P 1 ( T 2 /T 1 )− P 1 ). More simply, P c can be rewritten as follows: P c =P 1 (2− T 2 /T 1 ). As an example using a positive pressure test using the Cp sensor or sensor subsystem to generate a temperature-compensated or -corrected pressure output, the measured pressure decay determined by a comparison between P c and P 2 (the pressure measured at the second point in time) will be a function only of system leakage. If the temperature-compensated or -corrected pressure, P c , is greater than the actual, nominal pressure measured at the second point in time (i.e., when T 2 was measured), then there must have been detectable leakage from the system. If Pc is not greater than the nominal pressure measured at T 2 , no leak is detected. The leak detection system employing a sensor or subsystem according to the present invention will reach an accurate result more quickly than a conventional system, since time will not be wasted waiting for the system to stabilize. The Cp sensor or subsystem allows for leakage measurement to take place in what was previously considered an unstable system. FIG. 1 shows an automotive evaporative leak detection system (vacuum) using a tank pressure sensor 120 that is able to provide the values required for leak detection in accordance with options 1) and 2) above. The tank pressure/temperature sensor 120 should be directly mounted onto the gas tank 110 , or integrated into the rollover valve 112 mounted on the tank 110 . Gas tank 110 , as depicted in FIG. 1 , is coupled in fluid communication to charcoal canister 114 and to the normally closed canister purge valve 115 . The charcoal canister 114 is in communication via the normally open canister vent solenoid valve 116 to filter 117 . The normally closed canister purge valve 115 is coupled to manifold (intake) 118 of internal combustion engine 118 a. The illustrated embodiment of the sensor or subsystem 120 according to the present invention incorporates a pressure sensor, temperature sensor and processor, memory and clock, such components all being selectable from suitable, commercially available products. The pressure and temperature sensors are coupled to the processor such that the processor can read their output values. The processor can either include the necessary memory or clock or be coupled to suitable circuits that implement those functions. The output of the sensor, in the form of a temperature-compensated pressure value, as well as the nominal pressure (i.e., P 2 ), are transmitted to processor 122 , where a check is made to determine whether a leak has occurred. That comparison, alternatively, could be made by the processor in sensor 120 . In an alternative embodiment of the present invention, the sensor or subsystem 120 includes pressure and temperature sensing devices electronically coupled to a separate processor 122 to which is also coupled (or which itself includes) memory and a clock. Both this and the previously described embodiments are functionally equivalent in terms of providing a temperature-compensated pressure reading and a nominal pressure reading, which can be compared, and which comparison can support an inference as to whether or not a leak condition exists. FIG. 2 provides a flowchart 200 setting forth steps in an embodiment of the method according to the present invention. These steps can be implemented by any processor suitable for use in automotive evaporative leak detection systems, provided that the processor: (1) have or have access to a timer or clock; (2) be configured to receive and process signals emanating, either directly or indirectly from a fuel vapor pressure sensor; (3) be configured to receive and process signals emanating either directly or indirectly from a fuel vapor temperature sensor; (4) be configured to send signals to activate a pump for increasing the pressure of the fuel vapor; (5) have, or have access to memory for retrievably storing logic for implementing the steps of the method according to the present invention; and (6) have, or have access to, memory for retrievably storing all data associated with carrying out the steps of the method according to the present invention. After initiation, at step 202 (during which any required initialization may occur), the processor directs pump 119 at step 204 , to run until the pressure sensed by the pressure sensor equals a preselected target pressure P 1 . (Alternatively, to conduct a vacuum leak detection test, the processor would direct the system to evacuate to a negative pressure via actuation of normally closed canister purge valve 115 ). The processor therefore should sample the pressure reading with sufficient frequency such that it can turn off the pump 119 (or close valve 115 ) before the target pressure P 1 has been significantly exceeded. At step 206 , which should occur very close in time to step 204 , the processor samples, and in the memory records, the fuel vapor temperature signal, T 1 , generated by the temperature sensor. The processor, at step 208 , then waits a preselected period of time (e.g., between 10 and 30 seconds). When the desired amount of time has elapsed, the processor, at step 210 , samples and records in memory the fuel vapor temperature signal, T 2 , as well as fuel vapor pressure, P 2 . The processor, at step 212 , then computes an estimated temperature-compensated or corrected pressure, P c , compensating for the contribution to the pressure change from P 1 to P 2 attributable to any temperature change (T 2 −T 1 ). In an embodiment of the present invention, the temperature-compensated or corrected pressure, P c , is computed according to the relation: P c =P 1 (2− T 2 /T 1 ) and the result is stored in memory. Finally, at step 214 , the temperature-compensated pressure, P c , is compared by the processor with the nominal pressure P 2 . If P 2 is less than P c , then fuel must have escaped-from the tank, indicating a leak, 216 . If, on the other hand, P 2 is not less than P c , then there is no basis for concluding that a leak has been detected, 218 . The foregoing description has set forth how the objects of the present invention can be fully and effectively accomplished. The embodiments shown and described for purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments, are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the spirit of the following claims.

A method and sensor or sensor subsystem permit improved evaporative leak detection in an automotive fuel system. The sensor or sensor subsystem computes temperature-compensated pressure values, thereby eliminating or reducing false positive or other adverse results triggered by temperature changes in the fuel tank. The temperature-compensated pressure measurement is then available for drawing an inference regarding the existence of a leak with reduced or eliminated false detection arising as a result of temperature fluctuations.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This is a U.S. national application of International Application PCT/JP2010/063049, filed Aug. 3, 2010, which claims priority to Japanese Application No. 2009-183696, filed Aug. 6, 2009, the contents of each of which are incorporated by reference in their entireties for all purposes. FIELD OF THE INVENTION [0002] The present invention relates to an immune balance regulating agent comprising a preparation obtained by superheated steam treatment of garland chrysanthemum (crown daisy). BACKGROUND OF THE INVENTION [0003] Superheated vapor is a vapor which is heated at or above a temperature at which vapor and liquid can co-exist keeping equilibrium under a constant pressure, and for example, steam which is heated at or above 100° C. at 1 atm is called superheated steam. Technology utilizing superheated steam has extended to the fields of sterilization, drying, food processing and the like; technical developments have been carried out, which utilize the advantage of superheated steam treatment of not changing the quality such as color, flavor, taste, texture of food materials in the field of food processing among others [0004] Superheated steam treatment does not change the quality of food materials (Patent Literatures 3 and 4) and has effects of reducing undesirable excessive oils and fats and odor components as well. Furthermore, its utilization has also been advanced as a technology to enhance desired components, and for example, a quercetin-containing composition obtained by superheated steam treatment of quercetin glucoside-containing materials such as onion skin is disclosed in Patent Literature 5, and it is disclosed in Patent Literature 6 that superheated steam treatment of coffee beans provides roasted coffee beans with a decreased content of acrylamide and an increased contents of chlorogenic acids. [0005] Although it is thus expected to obtain a new material in which some physiological functions are provided or enhanced, a material with satisfactory physiological functions has not yet been obtained. SUMMARY OF THE INVENTION [0006] An object of the present invention is to provide a new application of a preparation obtained by superheated steam treatment. [0007] The present inventors have found that a preparation obtained by superheated steam treatment of garland chrysanthemum (crown daisy) exhibits an effect of alleviating allergic diseases caused by excessive type 2 immune response by regulating the immune balance, in addition to infection preventive and anti-tumor activities due to the effect of stimulating type 1 immunity, and completed each of the following inventions. [0008] (1) An immune balance regulating agent containing a preparation obtained by superheated steam treatment of garland chrysanthemum. [0009] (2) The immune balance regulating agent according to (1), which is used for anti-infectious disease. [0010] (3) The immune balance regulating agent according to (1), which is used for anti-tumor. [0011] (4) The immune balance regulating agent according to (1), which is used for enhancing type 1 immune system function. [0012] (5) The immune balance regulating agent according to (4), which is used for dendritic cell activation. [0013] (6) The immune balance regulating agent according to (4), which is used for promoting IFN-γ and/or interleukin (IL)-12 production. [0014] The immune balance regulating agent of the present invention is an extremely highly safe composition having an effect of regulating and normalizing the immune balance of a living body, comprising a preparation obtained by superheated steam treatment of garland chrysanthemum , which has been utilized as food from a long time ago, as an active component. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 is a diagram showing the upper and lower graphs show an effect of IFN-γ inducing production (promoting production) of the preparations obtained by superheated steam treatment of Example and Comparative Example 1, respectively. The longitudinal axis indicates IFN-γ production level and the abscissa axis indicates the preparations obtained by superheated steam treatment added. FIG. 2 is a diagram showing the influence of IL-12 on the induction of IFN-γ production from spleen cells by the preparation obtained by superheated steam treatment of Example. The longitudinal axis indicates the IFN-γ production level, and the abscissa axis indicates groups without and with the preparation obtained by superheated steam treatment of Example added (a group without addition and a group with garland chrysanthemum added), respectively. [0016] FIG. 3 is a graph depicting flow cytometric results demonstrating the dendritic cell activation effect of the preparation obtained by superheated steam treatment of Example. The abscissa axis indicates the expression level of the measurement target molecule on the cell surface; a group without addition denotes a group without the preparation obtained by superheated steam treatment of Example added and a group with garland chrysanthemum added denotes a group with the preparation obtained by superheated steam treatment of Example added, respectively. [0017] FIG. 4 is a diagram showing an IL-12 production induction ability, which demonstrates the dendritic cell activation effect of the preparation obtained by superheated steam treatment of Example. The longitudinal axis indicates the IL-12 production level and the abscissa axis indicates groups without and with the preparation obtained by superheated steam treatment of Example added (a group without addition and a group with garland chrysanthemum added), respectively. [0018] FIG. 5 is a diagram showing that the preparation obtained by superheated steam treatment of Example demonstrates, TLR (Toll Like Receptor)—dependently, an IFN-γ production inducing (production promoting) effect. The longitudinal axis indicates the IFN-γ production level and the abscissa axis indicates spleen immune cells of a 7-week-old C57BL/6 female mouse (wild type), spleen immune cells of a TLR2-deficient mouse, spleen immune cells of a TLR4-deficient mouse, and spleen immune cells of a TLR9-deficient mouse in the groups without and with the preparation obtained by superheated steam treatment of Example added (a group without addition and a group with garland chrysanthemum added), respectively. [0019] FIG. 6 is a graph depicting the results of the measurement of IFN-γ production in NK1.1-positive and TCR β-negative cells, NK1.1-positive and TCR β-positive cells, CD4-positive cells and CD8-positive cells, without and with the preparation obtained by superheated steam treatment of Example added (a group without addition and a group with garland chrysanthemum added), respectively, by flow cytometry using an intracellular staining method. The longitudinal axis of each graph indicates the expression level of the target molecule of measurement on each cell surface, respectively and the abscissa axis indicates the IFN-γ production level. [0020] FIG. 7 is diagram showing IFN-γ production levels in spleen immune cells of a 7-week-old C57BL/6 female mouse (control) and spleen immune cells of a 7-week-old C57BL/6 female mouse having no NK1.1-positive cells when preparation obtained by superheated steam treatment of Example is not added (a group without addition) and added (a group with garland chrysanthemum added). The longitudinal axis indicates the IFN-γ production level and the abscissa axis indicates respective cells in the groups without and with the preparation obtained by superheated steam treatment of Example added (a group without addition and a group with garland chrysanthemum added). [0021] FIG. 8 is a diagram showing IFN-γ production inducing (production promoting) effect of the preparation obtained by superheated steam treatment of Example (garland chrysanthemum nepurée) and the preparation obtained by ordinary heat treatment of Comparative Example 2 (garland chrysanthemum purée). The longitudinal axis indicates the IFN-γ production level and the abscissa axis indicates groups without and with the preparation obtained by superheated steam treatment of Example added (a group without addition and a group with garland chrysanthemum added), respectively. DETAILED DESCRIPTION OF THE INVENTION [0022] The present invention is an immune balance regulating agent containing a preparation obtained by superheated steam treatment belonging to Chrysanthemum Asteraceae , leaves and stems of which are generally considered to be edible and widely distributed domestically in Japan as a commonly ingested vegetable. [0023] In carrying out the present invention, any edible garland chrysanthemum can be used, and for example, the species termed as Chrysanthemum coronarium in nomenclature can be used. [0024] It should be noted that garland chrysanthemum is known to contain a plenty of vitamin C and carotene as nutrients but nothing is known with regard to its immunoregulating effect. [0025] The superheated steam treatment is carried out using garland chrysanthemum as it is or after ground in to an adequate size. The garland chrysanthemum may be raw or dried. [0026] The temperature of steam used for the superheated steam treatment ranges preferably from approximately 120° C. to 500° C., more preferably from 230° C. to 280 20 C. The time for the superheated steam treatment will be set appropriately depending upon the size and quantity of a material, and the time ranging approximately from 30 seconds to 240 seconds is preferable in order for the function of immune balance regulating agent of the present invention to be satisfactory. [0027] In addition, the superheated steam treatment may be carried out twice or more with the condition kept the same or changed with regard to the temperature or time condition; furthermore, a grinding process may be incorporated between two or more superheated steam treatments as described in the above-described Patent Literature 1. [0028] A material after superheated steam treatment can be utilized not only as it is for the immune balance regulating agent of the present invention, but also can be used after further treatment such as solid/liquid separation by centrifugation or filtration, extraction using a solvent such as water, alcohols such as ethanol and a mixture thereof, and drying such as spray drying and freeze drying; all of them are called herein “preparation obtained by superheated steam treatment”. [0029] Immune balance regulation, that is, the immune balance regulating effect in the present invention, means an effect which resolves the state in which either one of a type 1 immune system function or a type 2 immune system function, especially the type 2 immune system function is enhanced, and leads to the state where the both immune system functions are regulated. Regulation of immune balance meant in the present invention is used interchangeably with modulation or adjustment of immune balance. [0030] Generally, the type 1 immune system is understood as an immune system involving Th1 cells (type 1 helper T cells) induced by the presentation of an antigenic peptide from dendritic cells and/or macrophages which are antigen-presenting cells and by the effects of IL-12 and/or IFN-γ. Th1 cells produce IL-2, TNF-α, etc., in addition to cytokines such as IFN-γ which suppress the production of IgE antibody through the inhibition of differentiation of Th2 cells (type 2 helper T cells) and the inhibition of maturation of B cells to activate cell-mediated immunity such as killer T cells and enhance the activity of antigen-presenting cells such as dendritic cells and macrophages. On the other hand, the type 2 immune system is understood to be an immune system involving Th2 cells induced by the presentation of an antigenic peptide from macrophages that are antigen-presenting cells and by the effect of IL-4. Th2 cells produce IL-5, IL-6 and IL-10 in addition to cytokines such as IL-4 and IL-13 which enhance the production of antibodies such as IgE through the maturation of B cells and activate humoral immunity. [0031] It is known that IL-4 and IL-10 produced from Th2 cells control the effect of each other to suppress the production of IFN-γ from Th1 cells. It is believed that if the type 2 immune system function is predominant, cell-mediated immunity is suppressed and an infectious disease tends to be serious, and further, IgE antibody production through the maturation of B cells increases, likely leading to allergic predisposition. Therefore, breaking of the balance of the type 1 immune system function and the type 2 immune system function, particularly, excessive enhancement or dominance of the type 2 immune system function is not always preferable for a living body. [0032] The preparation obtained by superheated steam treatment used in the present invention exhibits effects of activating dendritic cells and natural killer cells (NK cells), natural killer T cells (NKT cells), and inducing or promoting the production of IFN-γ and IL-12. The effects of activating NK cells and NKT cells may include, for example, an effect of inducing the production of IFN-γ in NK cells and NKT cells. Thus, by administering the immune balance regulating agent of the present invention to an individual having an enhanced type 2 immune system function among others, the type 1 immune system function can be enhanced, resulting in regulation of the immune balance. In this way, the preparation obtained by superheated steam treatment used in the present invention can be utilized as a type 1 immune system function enhancer to enhance the type 1 immune system function, as well as a dendritic cell activator, an NK cell activator, an NKT cell activator, an IFN-γ production promoter, and an IL-12 production promoter. [0033] In addition, a physiological activity presented by the above mentioned preparation obtained by superheated steam treatment used in the present invention has been confirmed, quite unexpectedly, to be very strong compared to a case where ordinary heat treatment is carried out using the same material. [0034] Furthermore, the preparation obtained by superheated steam treatment used in the present invention can alleviate a condition in which the type 2 immune system function is dominant, for example, allergy, by enhancing the type 1 immune system function, or it is effective in the treatment of diseases such as infectious diseases and malignant tumors in which enhancement of cell-mediated immunity is required, in addition to the treatment of allergic diseases, because it can induce the production of IFN-γ in NK cells and NKT cells to yield an infectious disease suppressing effect and an anti-tumor effect. In other words, a preparation obtained by superheated steam treatment used in the present invention can be utilized as an allergy, an inhibitor, an infectious disease inhibitor, and an anti-tumor agent. [0035] In addition, it can be expected that the preparation obtained by superheated steam treatment used in the present invention has effects of balancing the type 1 immune system function and the type 2 immune system function usually by its oral application, enhancing resistance against the invasion of foreign matters such as infectious diseases, and further, alleviating allergy and autoimmune diseases that are excessive immune response. [0036] Specifically, the prevention, treatment or effect of improving symptoms of infectious diseases with viruses or bacteria, tumors, inflammation, allergic diseases such as atopic dermatitis, skin roughness, sensitive skin, pollinosis, asthma, bronchial asthma, rhinitis, urticaria, and the like can be expected for the immune balance regulating agent of the present invention. [0037] The preparation obtained by superheated steam treatment of the present invention can be used as an immune balance regulating agent as it is, as well as for a pharmaceutical composition such as a prophylactic, suppressive or therapeutic agent for infectious diseases, an anti-tumor agent, and a prophylactic, suppressive or therapeutic agent for allergic diseases. In addition, it can be combined with common excipients to prepare a composition and the composition can be further formulated into common dosage forms of external use for skin, oral formulations, injections, and others. [0038] The above-mentioned compositions or various dosage forms may be provided in a form of drug or quasi drug, by incorporating pharmaceuticals such as vitamins, galenicals, anti-inflammation agents, antihistamic agents, etc., as an active component, if necessary, in addition to the preparation obtained by superheated steam treatment. [0039] As the excipients used in formulation, for example, ingredients widely known and used by those skilled in the art for each dosage form of a solid oral formulation such as a tablet or a capsule, a liquid internal formulation such as aqueous liquid or suspension, ointment, patch, lotion, cream, spray, suppository, etc., can be used in a proper combination with each other. [0040] The amount of the preparation obtained by superheated steam treatment incorporated in the above mentioned composition or dosage form is not specified, somewhat different depending upon the type of dosage form, quality and the degree of expected effect, may be from 1 to 99% by weight, preferably from 10 to 99% by weight, more preferably from 50 to 99% by weight as a dry solid in the total amount of the composition or formulation. [0041] The immune balance regulating agent of the present invention may be formed into a beverage such as a juice or a milk beverage, a dairy product such as yogurt or ice cream, and foods such as soup, jelly, jam, confectionery or breads as it is or in combination with a proper component for beverages or foods; further, it may be formed into a health food or supplement. When the immune balance regulating agent is ingested or administered in the combination with a food, it can be mixed with an excipient, a filler, a binder, a thickener, a emulsifier, a coloring agent, a flavor, a food additive, a condiment or the like, as appropriate, and formed into powder, granules, and tablets depending upon the intended use. Furthermore, it can be ingested by being mixed in a raw material of food to prepare a food, and commercialized as a functional food. [0042] Since the raw material of the preparation obtained by superheated steam treatment used in the present invention is food, the amount of ingestion in a form as the above-mentioned beverage or food is not particularly restricted. An ingestion amount within the range of being ordinarily used as food is desirable, and specifically the amount is from 0.5 to 250 g, preferably from 1 to 200 g per ingestion, and the total amount of ingestion per day is from 0.5 to 500 g, preferably from 1 to 400 g. [0043] In the following, the present invention will be described in more details with reference to Example, but it should not be construed that the present invention be restricted by such an Example. EXAMPLE Example [0044] Three kg of garland chrysanthemum ( Chrysanthemum coronarium ) cut to a length of 4 cm was superheat-treated with a high temperature steam under atmospheric pressure for 10 minutes. Garland chrysanthemum after the treatment was treated with “high speed planetary mixer NewTon UM-N13” made by NAGATA SEIKI CO., LTD. at 1100 rpm, for 100 seconds. The garland chrysanthemum treated with the mixer was treated with an ultracentrifuge (SCR2OBA: Hitachi, Ltd.) at 2000 revolution (25,000×g) for 10 minutes to obtain a precipitated fraction and a supernatant fraction, which supernatant fraction was dried using a freeze dryer to prepare a water soluble fraction. Then, the precipitated fraction was suspended in 10 times volume of a 30% by volume ethanol aqueous solution and after stirred for 30 minutes, separated using a filter paper (Whatman Ltd.) into a solid component from the 30% by volume ethanol aqueous solution and a filtrate from the 30% by volume ethanol aqueous solution. After the filtrate from the 30% by volume ethanol aqueous solution was treated with a concentration centrifuge (EYELA) and evaporated, an extracted fraction from the 30% by volume ethanol aqueous solution was prepared by cooling with liquid nitrogen and complete removal of the solvent with a freeze dryer. Subsequently, after the solid component from the 30% by volume ethanol aqueous solution was suspended in 10 times volume of a 60% by volume ethanol aqueous solution and stirred for 30 minutes, it was separated into solid component from the 60% by volume ethanol aqueous solution and filtrate from the 60% by volume ethanol aqueous solution using filter paper (Whatman Ltd.). An extracted fraction from the 60% by volume ethanol aqueous solution was prepared by treating the filtrate from 60% by volume ethanol aqueous solution in a similar manner to the filtrate from the 30% by volume ethanol aqueous solution. Comparative Example 1 [0045] An extracted fraction from the each 30% by volume ethanol aqueous solution was obtained in the same way as Example except that garland chrysanthemum of Example was replaced with carrot ( Daucus carota ), tomato ( Solanum lycopersicum ), spinach ( Spinacia oleracea ), or onion ( Allium cepa ). Comparative Example 2 [0046] After 2 L of water was placed in a relatively large pot and completely boiled, 100 g of garland chrysanthemum was added and heated for 3 minutes. Garland chrysanthemum after heated was thoroughly ground with ACE HOMOGENIZER (AM-3/KN3325012; NIHONSEIKI KAISHA LTD.). After that, ultracentrifugation and ethanol extraction were carried out in a similar manner to Example to obtain an extracted fraction from the 30% by volume ethanol aqueous solution. Test Example (1) IFN-γ Production Inducing (Production Promoting) Effect [0047] A spleen was taken from a 7-week-old C57BL/6 female mouse purchased from Charles River Inc. The spleen was loosened using tweezers in an RPMI-1640 medium (Wako Pure Chemical Industries, Ltd.) comprising 10% FCS, 2.38 mg/mL Hepes, 0.11 mg/mL sodium pyruvate, 200 U/mL penicillin G, and 0.1 mg/mL streptomycin. Cells were passed through nylon mesh (Wako Pure Chemical Industries, Ltd.) together with the culture and recovered with the tissue part being removed. After the centrifugation treatment using a small cooling centrifuge (himac CF7D2, Hitachi, Ltd.) at 1500 rpm for 5 minutes, the supernatant was discarded, and the sediment was incubated with 2 mL of 0.155 M ammonium chloride at 37° C. for 1 minute and 30 seconds to eliminate erythrocytes and to prepare spleen immune cells/the RPMI-1640 medium. Each of extracted sample obtained in Example and Comparative Example 1 was co-cultured from the concentration of 200 μg/mL, the culture being carried out using a carbon dioxide gas incubator at 37 ° C. under 5% CO 2 atmosphere. After 48 hours, the supernatant of the culture was recovered and the IFN-γ amount in the culture supernatant was determined using ELISA Mouse IFN-γ BD Opt EIA set (BD Biosciences). [0048] The results are shown in FIG. 1 . Only the extract from garland chrysanthemum with 30% by volume ethanol of Example demonstrated a strong activity of inducing IFN-γ production. [0000] (2) Effect of IL-12 on the Induction of IFN-γ Production from Spleen Cells. [0049] A similar experiment to (1) was carried out using the extract from garland chrysanthemum with 30% by volume ethanol of Example, except that the function of IL-12 was inhibited by adding a monoclonal anti-IL-12 antibody in the culture of spleen cells. [0050] The results are shown in FIG. 2 . It was confirmed that IFN-γ production induction by garland chrysanthemum was strongly suppressed by the addition of anti-IL-12 antibody, and thus it was shown that IFN-γ production was induced by IL-12. (3) Dendritic Cell Activation Effect [0051] Bone marrow cells were collected from the femora of a 7-week-old C57BL/6 female mouse purchased from Charles River Inc., seeded in a 6-well flat bottom plate (Nunc) to be 1×10 6 cells/well, and cultured in the presence of 10 ng/mL of GM-CSF (PeproTech Inc.) for 6 days to induce dendritic cells that are antigen-presenting cells. These cells and the extract from garland chrysanthemum with the 30% ethanol of Example were co-cultured an in RPMI-1640 medium containing 10% FCS, 2.38 mg/mL Hepes, 0.11 mg/mL sodium pyruvate, 200 U/mL penicillin G, and 0.1 mg/mL streptomycin. Expression levels after 24 hours of MHC class I molecules, MHC class II molecules, CD40 molecules and CD86 molecules on the cell surface were detected by flow cytometry (FACS Calibur; BD Biosciences) using an anti-MHC class I molecule antibody (AF6-88.5), an anti-MHC class II molecule antibody (AF6-88.5), an anti-CD40 antibody (3/23) and an anti-CD86 antibody (GL1). [0052] The results are shown in FIG. 3 . In the groups in which the extract from garland chrysanthemum with 30% by volume ethanol was added, a significant increase in expression of MHC class I molecules, MHC class II molecules, CD40 molecules and CD86 molecules was observed, compared to the control without addition. From this, the extract from garland chrysanthemum with 30% by volume ethanol was found to activate dendritic cells. [0000] (4) Ability of Inducing IL-12 Production from Dendritic Cells [0053] IL-12 production using the extract from garland chrysanthemum with 30% by volume ethanol of Example was studied in the same condition as (3). The amount of IL-12 p70 contained in the culture supernatant in recovering cells was determined using ELISA Mouse IL-12 p70 BD Opt EIA set (BD Biosciences). [0054] The results are shown in FIG. 4. It was confirmed that the extract from garland chrysanthemum with 30% by volume ethanol induced IL-12 production from dendritic cells. (5) Study of TLR Dependency in the Induction of IFN-γ Production [0055] A spleen was collected from a 7-week-old C57BL/6 female mouse purchased from Charles River Inc., or a TLR2 (Toll Like Receptor 2)-deficient mouse, a TLR4 (Toll Like Receptor 4)-deficient mouse and a TLR9 (Toll Like Receptor 9)-deficient mouse obtained from Oriental BioService, Inc., and an experiment was carried out using the extract from garland chrysanthemum with 30% by volume ethanol of Example in the same condition as (1). [0056] The results are shown in FIG. 5 . From the fact that induction of IFN-γ production from spleen cells by garland chrysanthemum was hardly observed when TLR4 was deficient, and attenuated when TLR9 was deficient, it has been revealed that the immune balance regulating effect by garland chrysanthemum is dependent strongly upon TLR4 and partly upon TLR9. (6) Identification of IFN-γ Production Inducing Cell [0057] Spleen immune cells/RPMI-1640 medium were prepared in the same way as (1). To this, 25 μg/mL of the extract from garland chrysanthemum with 30% by volume ethanol of Example was added, and cultured using a carbon dioxide gas incubator at 37° C. under 5% CO 2 atmosphere for 12 hours. After Brefeldin A (BFA) was added and an additional 12 hours elapsed, cells were recovered and reacted with an anti-TCR β antibody, an anti-CD4 antibody (GK1.5), an anti-CD8 antibody (53-6.7), an anti-NK1.1 antibody (PK136) and an anti-IFN-γ antibody (XMG1.2), and examined to detect IFN-γ production in NK1.1-positive and TCR β-negative cells, NK1.1-positive and TCR β-positive cells, CD4-positive cells and CD8-positive cells, by flow cytometry (FACS Calibur; BD Biosciences) using an intracellular staining method. [0058] The results are shown in FIG. 6 . NK1.1-positive and TCR β-negative cells are found to be NK cells due to expressing the marker of NK cells but not T cell specific marker, while NK1.1-positive and TCR β-positive cells are found to be NKT cells due to expressing the marker of NK cells as well as T cells specific marker. Further, it is revealed that NK1.1-positive and TCR β-negative cells and NK1.1-positive and TCR β-positive cells are activated by the addition of the extract from garland chrysanthemum with 30% by volume ethanol to induce IFN-γ production. From these facts, it has been shown that cells from which IFN-γ production is induced by the addition of the extract from garland chrysanthemum with 30% by volume ethanol are NK cells and NKT cells. (7) Confirmation of IFN-γ Production Induction in NK Cells and NKT Cells [0059] From the result of (6), an experiment for confirming IFN-γ production induction in NK cells and NKT cells by the addition of the extract from garland chrysanthemum with 30% by volume ethanol was further carried out. [0000] [7-1] [0060] 200 μg of an anti-NK1.1 antibody (PK136) was administered into the peritoneal cavity of a 7-week-old C57BL/6 female mouse purchased from Charles River Inc., and after 24 hours elapsed, the spleen was taken. After that, spleen immune cells/RPMI-1640 medium were prepared in the same way as (1), and after confirmed that NK1.1-positive cells, namely NK cells and NKT cells were not contained, 25 μg/mL of the extract from garland chrysanthemum with 30% by volume ethanol of Example was added and cultured using a carbon dioxide gas incubator at 37° C. under 5% CO 2 atmosphere for 48 hours. Subsequently, the culture supernatant was recovered, and the amount of IFN-γ in the culture supernatant was determined using ELISA Mouse IFN-γ BD Opt EIA set (BD Biosciences). [0000] [7-2] [0061] Spleen immune cells/RPMI-1640 medium were prepared in the same way as [7-1] except that an anti-NK1.1 antibody (PK136) was not administered, and to this added was 25 μg/mL of the extract from garland chrysanthemum with 30% by volume ethanol of Example, and cultured using a carbon dioxide gas incubator at 37° C. under 5% CO 2 atmosphere for 48 hours. Subsequently, the culture supernatant was recovered, and the amount of IFN-γ in the culture supernatant was determined using ELISA Mouse IFN-γ BD Opt EIA set (BD Biosciences), this being taken as a control. [0062] The results are shown in FIG. 7 . By comparison to the control, from the fact that the amount of IFN-γ in the spleen cells not containing NK cells and NKT cells was very low, it has been shown that the extract from garland chrysanthemum with 30% by volume ethanol activates NK cells and NKT cells to induce IFN-γ production, and IFN-γ, production of which is induced by the addition of the extract from garland chrysanthemum with 30% by volume ethanol, is mainly derived from NK cells and NKT cells. (8) Difference in IFN-γ Induction Activity by Extracting Methods [0063] In order to compare IFN-γ induction abilities in the superheated steam-treated sample of Example (garland chrysanthemum nepurée; “nepurée” is a registered trade mark) and in the ordinarily heat-treated sample in Comparative Example 2 (garland chrysanthemum purée), experiments were carried out using each extract with 30% by volume ethanol in the same way as (1). [0064] As the result, a stronger activity was demonstrated in nepurée (registered trade mark) as shown in FIG. 8 . From this result, it has been shown that a substance which induces the production of IFN-γ is contained naturally in garland chrysanthemum , and the activity is further enhanced by superheated steam treatment.

Disclosed is a novel use of superheated stream-treated material. Disclosed is an immune balance-regulating agent comprising a superheated steam-treated product of crown daisy ( Chrysanthemum coronarium ). This immune balance-regulating agent, which comprises, as the active ingredient, a superheated stream-treated product of crown daisy that has been used as a food for a long time, is a composition having a very high safety and exerting an effect of controlling and normalizing the immune balance of a living organism. The present invention has been completed based on the finding that the superheated steam-treated product of crown daisy has anti-infective and antitumor activities based on type-1 immune stimulating effect and, moreover, shows an effect of ameliorating allergic diseases, which are caused by excessive type 2 immune responses, by controlling immune balance.

FIELD OF THE INVENTION This invention relates to an apparatus for the electrolytic recovery of silver from solutions containing silver, in particular used photographic solutions such as fixing and bleach-fixing solutions. BACKGROUND OF INVENTION Electrolytic silver recovery from used photographic solutions is a common way to extend the life of such solutions. An apparatus for the electrolytic recovery of silver from solutions containing silver is known from United States patent U.S. Pat. No. 5,378,340 (Van be Wynckel et al. assigned to Agfa-Gevaert NV) issued Jan. 3, 1995. The apparatus comprises an electrolytic cell including: a housing; an anode having an exposed anode portion within the housing; and a cathode having an exposed cathode portion located within the housing and encircling the anode. In use, silver from the silver-containing solution is deposited on the face of the cathode which is directed towards the anode. After the cell is operated for some time, the cathode is removed from the cell and replaced. In a known method of removing silver from silver-containing aqueous liquids, the liquid to be treated is pumped into the electrolytic cell and electrical power is fed to the anode and the cathode to cause silver to be deposited on the cathode. The cathode is usually removable, and after a certain amount of silver has built up thereon, the cathode is removed and replaced. The build up of silver on the cathode surface during de-silvering has an effect upon the circulation of liquid within the cell, in particular the rate and uniformity of liquid refreshment at the cathode surface. This in turn has an effect upon the uniformity of the desilvering process. OBJECTS OF INVENTION It is an object of the present invention to overcome the aforesaid disadvantages. SUMMARY OF THE INVENTION We have discovered that this objective and other useful advantages may be achieved when a perforated screen is located between the anode and the cathode. According to the invention there is provided an electrolytic cell for removing silver from silver-containing aqueous liquids, comprising a housing, an anode positioned within the housing, and a cathode surrounding the anode in the housing, characterised by a perforated screen located between the anode and the cathode. The invention provides the advantage of a higher and more uniform desilvering speed, thought to be due to an improved liquid flow over the cathode surface. The housing may be of any suitable shape, but it is preferred to be generally cylindrical, the anode being in the form of a tube positioned axially within the housing. In any case, the anode is encircled by the cathode. The housing may include an inlet which opens into the cell between the anode and the cathode, and an outlet, for liquid being treated. The outlet may comprises a passage through the anode. The outlet passage may open from the interior of the cell at a level above the level at which the circulation passage opens into the cell, thereby defining a liquid level in the cell. Preferably, by positioning the lower edge of the cathode above the base of the housing, a sump is defined in the space therebetween. The cell may include a circulation pump connected between the circulation passage and the interior of the housing to circulate liquid being treated through the cell. It is particularly beneficial if this circulation pump injects recirculating liquid tangentially into the sump of the housing, since this arrangement results in efficient mixing of the liquid. In a preferred embodiment, the housing includes a base and the anode comprises a tube extending from the base. The tube may surround and be concentric with the outlet passage. The hollow interior of the tube may constitute a circulation passage, of annular cross-section, which surrounds the outlet passage. In a preferred embodiment, the top of the exposed anode portion lies below the top of the exposed cathode portion. This is easily achieved where the anode is supported within the housing from the base thereof. Thus, the housing is preferably formed of electrically non-conductive material, and comprises a base wall and side walls, the anode being supported by the base wall and the cathode being positioned adjacent the side walls. The cathode is preferably removable from the cell and comprises an electrical connection which may be positioned above the liquid level. In order to enable the cathode to be removed, a removable lid may be provided which, when secured to the housing, serves to hermetically seal the cell. Alternatively, the lid may be integral with the cathode. The cathode is preferably in sheet form and ideally has a frusto-conical cross-section, with its larger radius end uppermost, that is towards the circular upper opening of the electrolyte cell. This configuration enables easy removal of the cathode even after a silver deposit has built up there-on after use. Usable cathode materials include stainless steel, silver and silver alloys, and other conductive materials, the non-silver containing materials being preferred from the point of view of costs, while the silver-containing materials cause fewer starting-up problems. A cylindrical shape to the housing enables the cathode to be positioned near to the wall of the cell. By arranging for the lower edge of the cathode to be spaced from the base of the housing, it is possible for the reference electrode to be located in a side arm of the housing, the side arm opening into the housing below the level of the cathode. The material used for the anode is less critical than that used for the cathode, although platinated titanium is usually used. In a preferred embodiment, the perforated screen is so shaped and positioned as to collect debris falling from the cathode. To achieve this, the cathode has a cylindrical configuration and the perforated screen is shaped to define an annular chamber in which at least a lower edge of the cathode is located. The perforated screen may include a perforated floor portion adjacent an inlet to the housing, so that liquid entering the cell through the inlet is directed to the space between the cathode and the perforated screen. Preferably, the perforated screen is spaced from both the anode and the cathode, ideally by at least 10 mm from the cathode. For example, the perforated screen is spaced by from 30 to 40 mm from the cathode. The perforated screen may be formed of an electrically non-conductive plastics material, which ideally is resistant to the silver-containing liquid, for example PVC. The perforations of the perforated screen preferably occupy from 30% to 40% of its surface area. If the perforations occupy less of the surface area of the screen, the current flow may be unacceptably reduced. If the perforations occupy more of the surface area, then the benefits of improved liquid flow over the cathode surface may be lost. The average size of the perforations of the perforated screen is preferably from 8 mm to 10 mm. If the perforations are smaller, the flow of liquid therethrough may be hindered by viscosity effects. We have found that larger perforations result in a reduction in electrolysis speed. It is convenient for the perforated screen to be removable from the housing. The cell is preferably operated under negative pressure. A volumetric pump may be connected to the outlet of the cell. Where the cell is hermetically sealed, operation of the volumetric pump can be used to fill the cell with liquid through the inlet, by creating a negative pressure in the cell. The use of this arrangement enables the cell to work under negative pressure and also ensures that the liquid in the cell is de-aerated. This leads to more uniform deposition of silver at the cathode. It is desirable to stop the circulation pump when too much air passes through the outlet. To achieve this, an optical sensor, capable of distinguishing between fluid and air in the outlet, may be positioned between the cell and the volumetric pump, but above the latter. In this way deaeration of the cell can be achieved very quickly. Due to the action of the centrifugal pump, a vortex is formed above the outlet. The air in the vortex is sucked in by the volumetric pump. When too much air is sensed in the outlet, the circulation pump is caused to stop, while the volumetric pump continues to operate. When the circulation pump stops, the vortex remains for about one second, allowing even more air to leave the cell. Once the optical sensor detects fluid, the centrifugal pump starts again, but with less air in the cell. After a few such deaeration cycles, only a small air bubble is left. This bubble is too small to create a vortex and does not therefore enter the pumps. For optimum performance of the cell, it is important that the potential between the cathode and the reference electrode is accurately controlled. Usually the electrolytic cell further comprises a reference electrode for this purpose. The reference electrode may be positioned in a side arm of the housing, projecting into the sump. Where, for example, an Ag/AgCl reference electrode is used, the potential between the cathode and the reference electrode is about 400 mV. When the unit is to perform optimally, meaning employing the maximum current without causing side reactions to occur, the potential should be measured with an accuracy of some millivolts. The reference electrode may be a calomel type electrode or an Ag/AgCl type electrode. A suitable electrode has been disclosed in application EP 0 598 144 (Agfa Gevaert NV) filed Nov. 11, 1992 entitled "pH Sensitive Reference Electrode in Electrolytic Desilvering". The "solutions containing silver, " which can be desilvered using the apparatus according to the present invention, include any solution containing silver complexing agents, e.g. thiosulphate or thiocyanate, sulphite ions as an anti-oxidant and free and complexed silver as a result of the fixing process. The apparatus can also be used with concentrated or diluted used fixing solutions, or solutions containing carried-over developer or rinsing water. Apart from the essential ingredients, such solutions will often also contain wetting agents, buffering agents, sequestering agents and pH adjusting agents. The apparatus of the present invention can also be used for desilvering bleach-fixing solutions which may additionally contain bleaching agents such as complexes of iron(III) and polyaminocarboxylic acids. The desilvering process can be carried out batch-wise or continuously, the apparatus being connected to the fixing solution, forming part of a continuous processing sequence. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described by the following illustrative embodiments with reference to the accompanying drawings without the intention to limit the invention thereto, and in which: FIG. 1 shows a cross section of an electrolytic cell according to the invention; FIG. 2 shows schematically the liquid and electrical connections to the cell; FIG. 3 shows an enlarged section of a cell according to the invention and comprising a sealing with a circular section; FIG. 4 shows an enlarged section of a cell comprising a sealing with an initially rectangular section. DETAILED DESCRIPTION OF THE INVENTION As shown in the Figures, an electrolytic cell for removing silver from silver-containing aqueous liquids comprises a generally cylindrical bucket-shaped housing 10, formed of electrically non-conductive material such as PVC, and comprising a base 15, sides 16 and an upper portion 17. The upper diameter of the housing 10 is marginally larger than the lower diameter by a factor of 1.05. Positioned within the cell are a tubular anode 20 and a cylindrical cathode 30. A perforated screen 28 located between the anode 20 and the cathode 30. The perforated screen 28 is spaced from both the anode 20 and the cathode 30. Specifically, the screen 28 is spaced by about 35 mm from the cathode. The screen 28 is shaped to define an annular chamber 42 in which at least a lower edge 12 of the cathode 30 is located, the screen having a perforated floor portion 44. The inlet 18 is adjacent the perforated floor portion 44 of the screen 28. The perforated screen 28 is removable from the housing 10. The screen 28 is formed of PVC, which is electrically non-conductive and resistant to the silver-containing liquid. The perforations 41 of the perforated screen 28 occupy from about 30% to 40% of the screen surface area and are generally circular with an average diameter ranging from about 8 mm to about 10 mm, preferably about 9 mm. The screen 28 is so shaped and positioned as to collect debris falling from the cathode 30. A liquid inlet 18 leads through the base 15 of the cell and opens into the cell between the anode tube 20 and the cathode 30. An outlet 19 opens from the base 15 of the cell and leads to a relatively narrow PVC tube defining an outlet passage 21. An annular circulation passage 23 is thereby defined, which surrounds the outlet passage 21 and is concentric therewith. The outlet passage 21 opens from the interior of the cell at a level 25 above the level 26 at which the circulation passage 23 opens into the cell, thereby defining a liquid level in the cell. An annular PVC cap 37 sits on top of the anode tube 20 and includes a U-shaped cross-section channel 38 opening downwards at one end into the circulation passage 23 and at the other end into the interior of the cell. The cathode 30, formed for example of stainless steel covered with a thin layer of silver, is located in the cell 10 with its faces spaced from the sides 16. The lower edge 12 of the cathode is spaced above the base of the housing so as to leave a sump 13 from which a side arm 24 of the housing leads. The anode 20, in the form of a platinised titanium tube, is secured to the base 15 of the cell by means of a contact piece (not shown in detail) integral with the housing of the cell, which contact piece acts as an electrical connector for the anode. The anode tube 20 lies along the axis of the housing 10. Excessive build up of deposited silver towards the lower edge of the cathode 30 is reduced by ensuring that the bottom of the cathode 30 is positioned below the bottom of the exposed portion of anode 20. In particular this is achieved by the provision of a raised base portion 33, formed of an electrically non-conductive material such as PVC, which serves to shield the lower part of the anode 20 from the cathode 30. In this manner, electrical field lines do not extend from that portion of the anode 20 which is positioned below the level of the cathode 30. The raised base portion 33 also serves to control the vortex flow of liquid within the housing. A centrifugal circulation pump 50, together with an associated pump motor 52, is connected to the base of the cell and serves to circulate the liquid in the cell by removing liquid from the circulation passage 23 and injecting it tangentially into the sump 13 of the housing 10, as indicated by the arrows in FIG. 1. The reference electrode 45 is positioned in the side arm 24 of the housing and protrudes into the sump 13 of the cell. A suitable reference electrode is a pH sensitive glass electrode such as a YOKOGAWA SM21/AG2 or an INGOLD HA265-58/120 glass electrode. Not only does the raised base portion 33 influence the silver build-up towards the lower edge of the cathode 30 by screening it from the anode 20, but the reference electrode 45 more accurately measures the correct voltage because the electric field is more uniform. The upper part 17 of the cell is in the form of a neck portion having an opening defined by a stainless steel ring 22. The stainless steel ring 22 is permanently fixed to one end of a bolt 31 which extends through the wall of the cell and provides a connector for the cathode 30. Positioned in the neck of the cell, below the level of the annular ring 22, is a sealing ring 14. The apparatus further comprises a lid 40 so shaped as to fit into the neck portion of the cell. The lid 40 is formed of electrically non-conductive material such as PVC. The cathode 30, formed for example of a stainless steel sheet having a thickness of 100 μm, is wrapped around into a cylindrical configuration. The cathode 30 is provided with a deformable upper edge portion, formed by the provision of slots (not shown), the sheet material of which the cathode is formed being sufficiently resilient to allow the upper edge portion to bend outwardly in response to outwardly directed force. As the lid is screwed into place, a contact surface on the lid bears against the upper edge portion of the cathode 30, causing the upper edge portions to bend outwardly against the annular surface of the ring 22 (see also the illustrations with greater details of FIGS. 3 and 4, which will be described in the following paragraphs). Tightening of the lid causes the upper edge portion to be clamped firmly by the lid against the ring 22, thereby establishing good electrical contact there-between. In the closed position of the lid, the sealing ring 14 bears against the lower edge of the lid 40, thereby forming a tight seal. According to further preferred embodiments of the present invention, sealing ring 14 comprises a circular section (also known as an "O-ring") or a flat (or rectangular) section. Enlarged views of two thus preferred sealings are given in FIGS. 3 and 4. Evidently, the geometry of the indicated cross-sections may be deformed during application; so, FIG. 4 illustrates a deformation of an initially flat section of a sealing ring 14. The liquid and electrical connections to the cell are shown schematically in FIG. 2. Fixer or other silver-containing liquid enters along an inlet line 27 having an internal diameter of, for example, 10 mm. When the cell is initially empty, but the lid 40 is attached hermetically sealing the cell, operation of a volumetric pump 29 extracts air from the cell and pulls liquid from the inlet line 27 into the cell through the inlet 18. Treated liquid from the cell is pumped by the pump 29 along an exit line 32, of say 10 mm diameter at say 1 liter/min. An optical level sensor 39 is provided in a cavity adjacent the exit line 32 at a position above the level of the volumetric pump 29. This sensor stops the circulation pump 50 each time too much air passes through the cavity. The volumetric pump 29 continues to operate however. By this arrangement, de-aeration of the cell proceeds quickly. Due to the action of the circulation pump 50, a vortex is formed above the outlet passage 21. The air of the vortex is sucked in by the volumetric pump 29. This air is sensed by the sensor 39 which causes the circulation pump 50 to stop. The vortex remains for about one second, allowing even more air to leave the cell. Once the sensor 39 detects liquid, the circulation pump 50 is caused to re-start. Further pumping not only continues to fill the cell, but also de-aerates the liquid in the cell. After 2 to 4 de-aeration cycles, in a span of less than a minute, only a small air bubble is left above the outlet passage 21. This bubble is too small to create a vortex and no further air enters the outlet passage 21. The liquid is circulated through the cell by the circulation pump 50 at, for example, 20 liters/min. The cell is then operated under usual conditions, during which a silver deposit builds up on the cathode 30, primarily on the inside surface thereof. Electronic circuitry 36 controls the de-silvering process in a known manner. After a period of time determined by the required amount of deposited silver, the operator unscrews the lid 40 and lifts the cathode 30 out of the cell. Due to the frusto-conical cross-section of the housing 10, the sides of the cathode will not foul against the ring 22, even when some small amount of silver deposit has built up on the outside surface thereof. The silver deposit is then removed from the cathode, which may then be re-used as desired or replaced by another cathode of similar construction for the de-silvering of a further batch of electrolyte. The cell may be drained via a drain valve 34 and drain line 35. Now, particular attention may be focused on two specific requisites to be accomplished by the electrolytic cell. One, a good sealing function has to be guaranteed. This is provided by the fact that, as mentioned before, when the lid 40 is attached to the housing 10 of the cell and the sealing ring 14 is mounted in the neck of the housing 10, the cell is hermetically sealed, especially as the volumetric pump 29 extracts air from the cell and thus provides that the cell is operated under negative pressure. It has been proved in practice that sealing by line-contacts is very efficient. Two, a good electrical contact between contact ring 22 and cathode 30 has to be guaranteed also. In the case of using a flat sealing ring 14 conforming to FIG. 4, a greater flexibility of the sealing ring itself may be expected, evidently dependent on the exact kinds and dimensions of the circular versus flat sealing rings. Therefor, greater geometrical tolerances on the mechanical parts of the cell can be accepted, which provides an extra advantage. Per further consequence of the flexibility, the force needed for a sufficient displacement of the lid into the cell may be smaller than in the case of a circular sealing ring 14 conforming to FIG. 3. And, for a same negative pressure in the cell, the electrical contact between ring 22 and cathode 30 may be more intense with a flat ring conforming FIG. 4, than in the case of a circular sealing ring 14 conforming FIG. 3. REFERENCE NUMBER LIST housing 10 lower edge 12 sump 13 sealing ring 14 base 15 sides 16 upper portion 17 outlet 19 inlet 18 anode tube 20 outlet passage 21 ring 22 circulation passage 23 side arm 24 liquid level 25 circulation level 26 inlet line 27 screen 28 vol pump 29 cathode 30 bolt 31 outlet line 32 drain valve 34 raised base portion 33 drain line 35 controller 36 cap 37 U-channel 38 sensor 39 lid 40 perforations 41 annular chamber 42 floor portion 44 reference electrode 45 circ pump 50 pump motor 52

The cell comprises a housing (10), an anode (20) positioned within the housing (10), and a cathode (30) surrounding the anode (20) in the housing (10). A perforated screen (28) is located between the anode (20) and the cathode (30). The construction provides the advantage of a higher and more uniform desilvering speed, due to an improved liquid flow over the cathode surface.

BACKGROUND AND OBJECTS OF THE INVENTION This invention relates to a bracket for supporting a rigid anchoring platform used in connection with the retaining walls of an excavation. More particularly it deals with a bracket or bracket assembly used in pairs and which may be reusable to support a rigid anchoring platform which in turn is connected to a buried anchor behind the retaining wall and through which a rod or cable may be tightened so as to exert retaining force upon the walls. During the construction of a large building such as a high-rise and the like, the excavation for the foundation and subfloors requires the presence of temporary lateral walls so that the adjoining earth, mud, etc. will not fall or flow back into the excavated site. Normally this is accomplished by driving supporting beams such as I-beams in spaced proximity to each other around the periphery of the excavation and then placing heavy planks or plates between the open U-shaped sections of the adjacent I-beams. These planks or plates form the retaining walls. It is also normal and often necessary to further brace these walls by mounting rigid anchoring platforms which are connected to the outer faces of the I-beams and span adjacent I-beams. Connecting rods or cables are connected to these platforms. The other ends of the rods or cables are attached to a fixed weight or "dead man" embedded in the earth in back of and generally below the wall and below and, of course, at an angle to the position of the support. The end of the cable or rod attached to the support may then be tensioned by known means so as to exert a stabilizing force upon the walls via the I-beams such that the walls cannot move inwardly into the excavation. Generally these cables are called "ties" and the supports to which they are attached referred to as "tie back wales" although other nomenclature is common. Generally the "tie back wale" or rigid support or platform takes the form of back to back channel irons with spacers welded between them or a modified I-beam although any rigid support spanning the adjacent beams may be utilized and for purposes of illustration in this invention may be assumed that such support is a flat, rigid member such as a steel elongated plate. In order to properly fix this anchoring platform or plate in position, it is necessary that it be rigidly attached to the I-beams at the opposite ends thereof and be positioned with respect to the outer face of the I-beams such that the face of the plate is at an acute angular relationship to the I-beams. This is necessary since the anchor is in back of and below the position the platform is attached to the I-beams to assure adequate holding force to the walls. Generally in present construction sites this requires that intermediate triangularly shaped plates be welded initially to the outer surface of the adjacent I-beams and then the rigid member positioned in contact with the slanted outer face of the intermediate plate and welded thereto. This system works properly if the adjacent I-beams being utilized are perfectly square with each other (that is, aligned so that their outer faces are in the same vertical plane) which is often not the case. Accordingly a considerable amount of trial and error welding, breaking the weld, repositioning, and rewelding is necessary at the construction site which is not only time consuming but also dangerous especially during wet weather or an overall wet environment at the construction site. Accordingly it would be very desirable to be able to assure that the intermediate supporting members each and every time provide square and level surfaces for the support to be affixed to as by welding. This and other objects of the present invention which will become apparent hereinafter are accomplished by the bracket of the present invention. Such bracket includes a vertically oriented generally planar first plate having inner and outer faces, said first plate having means outwardly extending from said inner face for at least temporarily supporting said bracket upon the flat face of a beam such as an I-beam, a body member mounted on said first plate and projecting outwardly from the exterior surface thereof in a plane generally normal to said exterior surface, said body further mounted on said first plate for at least limited pivotal motion therewith, said body having a second plate fixedly attached thereto and disposed on the body side distal from its connection with said first plate, said second plate having an outer planar surface disposed at an acute angle to said first plate wherein appropriate pivoting of said bodies with respect to the first plates of a pair of brackets mounted on a pair of spaced beams disposes said second plates in the same plane for receipt of opposite ends of a rigid member such as an anchoring platform. Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings. DESCRIPTION OF THE DRAWINGS In the drawings which illustrate the best mode presently contemplated for carrying out the present invention: FIG. 1 is an elevational view of a portion of an excavation site wall in which two bracket assemblies of the present invention have been utilized to support a rigid anchoring platform spanning two adjacent beams; FIG. 2 is a partial perspective showing the bracket of the present invention mounted upon the face of a beam; FIG. 3 is a top view of the bracket assembly shown in FIG. 2; FIG. 4 is a side view thereof on a reduced scale and further showing the manner in which a cable or rod may be tied to a anchor buried behind the wall; and FIG. 5 is a side elevational view similar to FIG. 4 but on a larger scale and showing how differing shaped second plates may be utilized in conjunction with the bracket assembly so as to support the anchoring position in varied angular relationship to the beams. DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings and particularly FIGS. 1 and 4, the overall excavation site environment in which the present bracket assembly 10 is utilized is best illustrated. Therein a pair of bracket assemblies 10 are shown in use position upon adjacent I-beams 12 embedded into the earth E at an excavation site. The I-beams 12 are normally embedded against earth walls W formed by the undug or back filled earth and in which an anchor or "dead man" 14 is buried. Such anchor can take the form of a block of precast concrete or poured in situ concrete in which a rod or cable 16 is permanently embedded at one end. The other end of the rod 16 is threaded and projects upwardly between the space between the adjacent I-beams 12 and into operative connection with a bolt 18 or other adjustment mechanism associated with a rigid anchoring platform 20. For illustrative purposes, the platform 20 is shown as a horizontal unyielding beam extending between the bracket assemblies 10 and the adjustment mechanism is shown as a simple nut 18 threadably connected with the threaded end 17 of the rod 16. In that regard, the threaded end 17 passes through an opening 22 in the rigid member 20. It should be pointed out that although operative, this construction is primarily shown for illustrative purposes in that a more complex locking device forming part of a "tie back wale" and a more complicated anchoring platform both of which form no direct part of the present invention may be utilized. These are of known construction and presently in use in the construction trades at the present time. In that regard, one of the keys of the present invention is the use of the novel bracket assemblies such that the conventional "tie back wale" and anchoring platforms presently utilized can be more efficiently assembled at the construction site with both less effort and with the opportunity of use less skilled personnel in performing such tasks. This results in significant time and cost savings over the methods now utilized. Such presently utilized methods involve the permanent welding of triangularly-shaped (generally a right triangle) bracket insert directly to the outer face of the adjacent I-beams 12. After such has been completed the anchor platform 20 or one of equivalent construction is positioned across the adjacent I-beams 12 and positioned on the slanted face of the triangular bracket. Inasmuch as the I-beams 12 are often canted or otherwise not square with respect to each other, it is often the case that the rigid platform 20 does not squarely sit upon or lie flush with the slanted edge of each bracket. This requires that the weld between the platform and the bracket or the bracket and the I-beam of either or both of the I-beams must be broken and re-welded. This must take place on the site, involves highly skilled and highly paid welders and involves a trial and error process that can take hours and, accordingly, hold up delay other workmen while assuring that the walls W are properly shored for continuing excavation or other foundation structual work on the project. The use of the assembly brackets 10 of the present invention alleviate these problems in that it assures that a pair of support bracket surfaces are available such that the rigid platform will meet squarely with them and thus assures that only a weld need to take place between that surface and the rigid platform or in some cases even permits the mechanical fastening as by bolts of the rigid platform to the supporting surfaces. Turning now to the drawings in general, the construction of each bracket assembly 10 will now be more fully explained. Therein each bracket includes a generally planar first plate 24 having an outer face 26 and a inner face 28. Outwardly extending from the inner face 28 are inwardly downwardly extending pins 30 adapted to extend into holes 32 formed in the outer surface of the I-beam outer face 34 and extend therebelow. Four such pins 30 are shown which cooperate with four openings in the I-beam face 34 such that the first pate 24 may be securely yet mechanically removably mounted upon the I-beam 12. A body member 36 formed by a pair of panels 38 spaced from each other so as to form a slot 40 therebetween outwardly projects from the outer face 26 of the first plate 24. The plate 24 is further provided with outwardly projecting spaced pintles 42 adapted to receive pintles 44 positioned on the inner edge of the body member 38. A pin 46 is adapted to extend through the pintles 42, 44 such that the body member 38 is hingedly connected to the first plate 24. The outer edge of the body member 38 is appropriately shaped to receive a second plate 48 in the open slot 40. Such second plate 48 is generally formed from a body portion or tongue 50 of generally triangular configuration which extends into the slot 40 and is fixed in position by a series of bolts and nuts 52 extending through aligned holes (not shown) extending through the panels 38 and the inner portions of the second plate body portion 50. In this regard, the lower portion of the body member 36 is not provided with an open slot 40 but either provided with a lower member welded to both the panels 38 or configured so as to form, a shelf 54 upon which the lower edge 56 of the tongue 50 is adapted to rest. The outer edge of the tongue 50 is provided with a outer planar surface 58 disposed at right angles thereto and adapted to in turn support the ends of the rigid anchoring platform 20 in contact therewith. In that regard, the second plate outer surface 58 is either provided with bolt openings (not shown) or the anchoring platform 20 is welded directly thereto once it has been placed in aligned positioned as will hereinafter be explained. Once the pair of bracket assemblies 10 have been mounted upon adjacent spaced I-beams 12, the rigid anchoring platform 20 may be positioned so as to span the space between the I-beams and rest upon the second platform 58 at each end thereof. In this regard, it should be pointed out that if either of the I-beams 12 are not in the same plane, that is, if the outer surface of one of the I-beams, or both for that matter are canted with respect to each other, that such misalignment can be easily be corrected by pivoting one or both of the second plates with respect to its supporting first plate until such alignment is corrected, that is, presents a square surface at either end of the anchoring platform. With the present technology if the I-beams are canted with respect to each other, a hit or miss welding sequence with triangular brackets must be performed prior to arriving at such a square supporting position. The angle which the second plate outer planar surface 58 makes with the first plate 24 is, of course, fixed for any configuration plate 48 but since the plate is removable, various angled faces such as face 58a can be provided simply by using a plate 48a having a different angled face. It should also be pointed out that the second plate 48 and the body member 36 could be integrally formed which, of course, would require that entire integral unit to be changed if a different angle planar surface 58 were desired. Also the extent of the surface 58 could be reduced from that illustrated in area so long as it provided adequate support to the rigid platform 20. Thereafter the rod 16 is manipulated such that the threaded end 17 projects through the hole 22 and thereafter the bolt 18 tightened such that tension is brought to bear against the I-beams 12 such that the plates or boards 60 extending between the I-beams 12 and projecting into the open ends 62 thereof are in turn forced up against the wall W so as to insure that wall does not collapse at this area of the excavation. This procedure may be repeated at a number of positions around the excavation as required for safety purposes. After the foundation or other construction has been completed, the site can be back filled and the brackets reused simply by breaking the weld or other attachment between them an the rigid anchoring platform 20 and lifting them out of their mechanical interlock with the I-beams. This assures that the bracket assemblies can be reused without undue refitting or reconstruction. While there is shown and described herein certain specific structure embodying this invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.

A retaining wall anchoring system which includes a bracket assembly for mechanical removable positioning upon adjacent spaced retaining beams at a construction site. The bracket includes a first plate used for attachment to the beam and a body pivotally positioned therein on which a second plate is angularly positioned to present a square surface on which a rigid platform may be welded. The pivotal connection insures that the second plates can be positioned such that their receiving surfaces are in a common plane.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to an atomic force microscope, and more particularly to a flat-cantilever stylus for use in the atomic force microscope and a method of making the stylus. A tip of one of two principal surfaces of a cantilever is used as the stylus. 2. Description of the Prior Art Conventionally, a scanning tunneling microscope (hereinafter referred to as STM) has been developed as an instrument capable of observing the surface of a solid body on the order of atoms. However, since the STM detects a tunnel current between a sample and a stylus to observe the sample surface, it is impossible for the STM to observe the surface of an insulator. In order to solve this problem, an atomic force microscope (hereinafter referred to as AFM) for observing the sample surface by detecting forces acting between the sample and the stylus has been proposed. Similar to the STM, the resolution of the AFM depends greatly upon the radius of curvature of the tip of the stylus. The smaller the radius of curvature is, the higher is the resolution. In order to detect minute forces, the AFM requires a cantilever 25 having a stylus 26 formed on the tip thereof, as shown in FIG. 1. In some conventional AFMs, the tip of the cantilever is used as the stylus. A cantilever with an integrated pyramidal tip can be formed by using an etch pit as a mold. The stylus may be made by anisotropic etching. In recent years, styli having a radius of curvature of approximately 300 Å at the tip thereof have been obtained. Although the AFM styli are made by various methods as described above, each method has a problem or problems. When the tip of the cantilever is utilized as the stylus, there are no problems in connection with adhesive properties between the cantilever and the stylus, and the manufacturing processes are comparatively simple. However, the radius of curvature is not less than several thousand angstroms in the ordinary photoetching technique because the radius of curvature of the tip fully depends upon the accuracy of photolithography. Therefore, a microscope manufactured by this method is low in resolution. A maskless etching technique such as FIB (Focused Ion Beam) is required to make the radius of curvature smaller than the aforementioned size, but the manufacturing processes are complicated and the problem of cost occurs. In a stylus made with an etch pit of crystal employed as a mold, although the radius of curvature can be reduced to a comparatively small value, the manufacturing processes are complicated. Furthermore, since the adhesive properties between the stylus and the cantilever are poor, an observation in vibration mode is difficult. The manufacturing method utilizing anisotropic etching is susceptible to various parameters during etching and is poor in reproducing a stylus configuration. SUMMARY OF THE INVENTION The present invention has been developed to overcome the above-described disadvantages. It is accordingly an object of the present invention to provide an improved cantilever stylus for use in an atomic force microscope, which stylus has a tip having an extremely small radius of curvature. Another object of the present invention is to provide a method of making the above-described stylus. In accomplishing these and other objects, the cantilever stylus according to the present invention comprises a cantilever having a fixed end and a free end and having two principal surfaces, and first and second tip portions formed in the principal surfaces of the free end, respectively. The first tip portion has a radius of curvature less than 0.1 μm and protrudes beyond the second tip portion so that the first tip portion may be used to observe the sample surface. A method of making a cantilever stylus according another aspect of the present invention comprises the steps of: forming on the surface of a substrate a film consisting of a stylus material different from a material of the substrate; forming on a surface of the stylus material a resist thin film consisting of a material different from the stylus material and having a tip; etching the stylus material by making use of an isotropic etching technique so that the depth of etching is greater than the radius of curvature of the tip of the resist thin film; forming the stylus material so that a tip of one principal surface thereof has a radius of curvature less than 0.1 μm and protrudes beyond a tip of the other principal surface thereof; and removing at least the resist thin film and the substrate adhering to the tips of the stylus material. Since the tip of the resist thin film is formed by a conventional fine processing technique, the radius of curvature is greater than 0.1 μm. The thin film of the stylus material adjacent to the resist thin film is etched from both sides of the tip of the resist thin film using an isotropic etching technique. As a result, when the depth of etching is made greater than the radius of curvature of the tip of the resist thin film, at least the tip of one principal surface of the cantilever adhering to the resist thin film becomes very small in its radius of curvature. Further etching can make the radius of curvature of the tip of the other principal surface very small. Accordingly, the stylus having the radius of curvature less than 0.1 μm can be obtained by the conventional photoetching using the tip of one of the principal surfaces as the stylus, without using a fine processing technique on the order of submicrons such as the FIB. This stylus can contribute to an atomic force microscope having a high resolution. In addition, since the tip of the cantilever is used as the stylus, the cantilever and the stylus are formed into a one-piece construction, thereby overcoming the problem of the adhesive properties between the stylus and the cantilever. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and features of the present invention will become more apparent from the following description taken in conjunction with a preferred embodiment thereof with reference to the accompanying drawings, throughout which like parts are designated by like reference numerals, and wherein: FIG. 1 is a perspective view of a conventional cantilever stylus for use in an atomic force microscope; FIG. 2 is a perspective view of a cantilever stylus for use in an atomic force microscope according to a first embodiment of the present invention; FIG. 3 is a side elevational view of the cantilever stylus of FIG. 2 and a sample to be observed; FIGS. 4a to 4c are process diagrams indicative of processes for making the cantilever stylus of FIG. 2; FIG. 5 is a perspective view of a cantilever stylus according to a second embodiment of the present invention; FIGS. 6a to 6c are process diagrams indicative of processes for making the cantilever stylus of FIG. 5; and FIG. 7 is a view similar to FIG. 5, showing a modification thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, there is shown in FIG. 2 a flat cantilever 2 having a stylus 1 integrally formed therewith at the tip thereof according to a first embodiment of the present invention. This flat cantilever 2 is used in an atomic force microscope. As shown in FIG. 2, the cantilever 2 has one end fixedly connected to a base material 3 and the other end 4 free. The cantilever 2 further has two flat principal surfaces. The tip of one principal surface, protruding beyond the other, is used as the stylus 1. FIG. 3 shows the relationship between the cantilever stylus 1 and a sample 6 during an observation. In FIG. 3, the cantilever 2 forms an angle of approximately 20° with the sample 6 to be observed. When the cantilever stylus 1 is located in close proximity to a sample surface 7, forces are generated between atoms of the sample surface 7 and those of the cantilever stylus 1, thereby slightly bending the cantilever 2. These forces include attractive van der Waals forces, magnetic forces, electrostatic forces, and repulsive forces. Detecting the bending of the cantilever 2 by any suitable method makes it possible to observe the sample surface 7. FIGS. 4a to 4c depict processes for making the cantilever stylus for use in the atomic force microscope. A SiO 2 film 9 having a thickness of 1 to 2 μm is initially formed on the surface of a Si substrate 8, as a material of the cantilever stylus 1, by thermal oxidation. A WSi 2 film 10 having a thickness of 0.1 μm is then formed on the surface of the SiO 2 film 9 as a resist film. The WSi 2 film 10 is processed into a configuration having a tip 11 by the known photoetching technique (FIG. 4a). The radius of curvature of the tip 11 of the WSi 2 film 10 formed is approximately 0.5 μm. Then, the substrate 8 is submerged in a buffer etching solution (mixed solution of one volume of HF and six volumes of NH 4 F) to perform an isotropic etching of the SiO 2 film 9 for 20 minutes with the WSi 2 film 10 serving as the resist film (FIG. 4b ). In this embodiment, a tip having a radius of curvature of approximately 300 Å is formed. Then, the substrate is submerged in a dilute mixed solution of hydrofluoric acid and nitric acid to remove the WSi 2 film 10 by etching. Thereafter, the cantilever formed is caused to adhere to a base material 13 and the Si substrate 8 is removed by etching to complete the processes required for making the cantilever 2 and the stylus 1. The tip of the stylus 1 has a radius of curvature of 300 Å (FIG. 4c). The material of the stylus and that of the resist film is not limited to the combination of SiO 2 and WSi 2 , but Si 3 N 4 or the like may be used as the material of the stylus and a conventional photoresist material may be used as the material of the resist film. In this embodiment, although the tip of the protruding principal surface of the cantilever is used as the stylus, a considerably small radius of curvature and a high resolution can be obtained by using the tip of the other principal surface as the stylus. In this case, by the use of monocrystal Si as the Si substrate, the base material of the cantilever can be directly obtained from the Si substrate by the anisotropic etching, thereby simplifying the processes. FIG. 5 depicts a cantilever 15 and a stylus 14 integrally formed therewith according a second embodiment of the present invention. The stylus surface forms an angle of 55° with the cantilever 15. FIGS. 6a to 6c depict processes for making the cantilever stylus 14 of FIG. 5. An inclined <111> surface 17 of Si is initially formed on a monocrystal Si substrate 16 by the anisotropic etching (FIG. 6a). The <111> surface 17 formed makes a angle of 55° with an <100> surface 18. At this time, the angle of the inclined surface 17 may be controlled by another method. For example, a steep inclination can be obtained by spatter etching, and the inclination can be easily changed through wet-type processes because the amount of side etching changes according to the etching speed. After a SiO 2 film 19 having a thickness of 1 to 2 μm is formed on the surface of the substrate 16 by thermal oxidation as the material of the cantilever stylus, a WSi 2 film 20 having a thickness of 0.1 μm is formed on the surface of the SiO 2 film 19. The WSi 2 film 20 is processed by normal photo-etching so that at least the tip 21 is located on the inclined surface (FIG. 6b). Thus, a stylus 23 having a radius of curvature of 300 Å and making an angle of 55° with a cantilever 22 is formed by the processes as employed in the first embodiment (FIG. 6c). When the inclination of the stylus makes an angle of 45° to 90° with the cantilever, the tip of one principal surface protruding beyond the other principal surface can be used as the stylus. On the other hand, when the inclination of the stylus makes an angle of 0° to 45° with the cantilever, the tip of the principal surface of the latter can be used as the stylus. As the material of the stylus and that of the resist film, the combination of the materials as described previously can be used. In this embodiment, although the cantilever is made by utilizing the lower <100> surface of the Si substrate, the cantilever may be made by utilizing the upper <100> surface of the Si substrate. In this case, as shown in FIG. 7, the tip 24 of one principal surface protruding beyond the other principal surface can be used as the stylus at an inclination in the range of 0° to 90°. According to the present invention, without using a fine processing technique on the order of sub-microns such as the FIB, a stylus having a radius of curvature of the tip less than 0.1 μm and superior adhesive properties to the cantilever can be formed by conventional photoetching technique. As a result, an atomic force microscope high in reliability and in resolution and capable of observing a sample surface on the order of atoms can be obtained using the stylus according to the present invention. Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted here that various changes and modifications will be apparent to those skilled in the art. Therefore, unless such changes and modifications otherwise depart from the spirit and scope of the present invention, they should be construed as being included therein.

An atomic force microscope for observing a sample surface (7) is internally provided with a cantilever stylus (1, 14, 23) and makes use of atomic forces acting between the cantilever stylus (1, 14, 23) and the sample surface. The cantilever stylus (1, 14, 23) includes a cantilever (2, 15, 22) having a fixed end and a free end and having two principal surfaces. The cantilever stylus (1, 14, 23) further includes two tip portions formed in the principal surfaces of the free end, respectively. One of the two tip portions has a radius of curvature less than 0.1 μm and protrudes beyond the other tip portion so that the former may be used to observe the sample surface (7).

FIELD OF THE INVENTION [0001] The present invention relates to an opening and closing device for furniture provided with a latch adapted to facilitate operations to open and close movable parts of furniture, for brevity also called latch. STATE OF THE ART [0002] Known latches have the function of facilitating opening or closing of the doors of furniture or drawers, according to the application for which they have been designed. These latches produce a slight contrasting force during the closing action that is accumulated by elastic elements capable of releasing it in a subsequent phase when the reverse operation of opening is implemented. [0003] If a latch is used to facilitate opening of a drawer or door, the latter is maintained in its closed position by suitable and known devices, which can either be separate from the latch or integral with it, for example hooks, magnets or the like. [0004] To open the drawer or door it is first necessary to apply a slight thrust to the drawer or door to release the latch, which returns the elastic energy accumulated during the closing operation and exerts a force on the drawer, generally created by springs, in the opening direction. An advantage of these devices is that they also make it possible not to use handles or other similar grasping elements on the drawer, which are not always appreciated for aesthetic or other reasons. [0005] Generally, one part of the elements constituting the latches is placed on fixed elements of the furniture to which the drawer belongs and another part on the drawer itself; moreover, these are constituted by a large number of elements that can make assembly by inexperienced personnel difficult. [0006] Some known latches are described in the documents DE 29507917U, DE 3816091, DE 19753319 and DE 10008350. However, these are devices that are complex to manufacture or to mount, some of which are too delicate to guarantee long-lasting operation. SUMMARY OF THE INVENTION [0007] A main purpose of the present invention is therefore to produce a latch that overcomes the drawbacks indicated hereinbefore in a simple and inexpensive way and which is compact, sturdy and easy to apply to furniture, particularly to doors. Therefore, the present invention solves the problems mentioned hereinbefore by producing a latch with the characteristics claimed in claim 1 . [0008] In particular, the invention relates to a latch device, which can be locked and released by the action of an external force produced by one or more springs, comprising a slider. The slider is suitable to translate along a guide, integral with a fixed part of the furniture, inclined by an angle differing from zero with respect to the direction in which the external closing force is applied, and has a hook that may be caught by the movable part of the furniture. Moreover, elements suitable to lock or to release the slider according to the function implemented are provided between the slider and the container. [0009] Thanks to the solution of the invention, the latch has a simple and compact structure that can be applied simply to drawers or doors of furniture, thus guaranteeing exact positioning with respect to the parts and consequently its correct operation. It is also characterized by fast and easy mounting that can be performed without the use of special tools. [0010] The latch device is also sturdy and secure against any danger of becoming detached from the furniture element to which it is fixed. The latch also has compression springs or equivalent elastic means capable of controlling sufficient opening travel to allow easy manual grip to complete opening of the drawer or, if necessary, even to completely eliminate this action. [0011] The dependent claims describe preferred embodiments of the invention. BRIEF DESCRIPTION OF THE FIGURES [0012] Further characteristics and advantages of the invention shall become more evident in the light of the detailed description of preferred, although not exclusive, embodiments of a latch, provided as non-limiting examples, with the aid of the accompanying drawings, wherein: [0013] FIG. 1 shows a side view of the latch device of the invention in a first operating position; [0014] FIG. 2 shows a side view of the latch device in FIG. 1 in a second operating position; [0015] FIG. 3 shows an exploded axonometric view of the latch device in FIG. 1 ; [0016] FIG. 4 shows an axonometric view of an element forming the latch device in FIG. 1 ; [0017] FIG. 5 shows an axonometric view of an element forming the latch device in FIG. 1 ; [0018] FIG. 6 shows a side section of an embodiment of the latch device of the invention; [0019] FIG. 7 shows an exploded axonometric view of the latch device in FIG. 6 ; [0020] FIG. 8 shows four different operating phases of the latch according to the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0021] With reference to the Figures cited, a latch device is represented, globally referenced with the reference T, generally, although not necessarily, fixed in one part thereof to a suitable structure of furniture 57 , and in another part thereof to a door 58 . It is however possible to kinetically invert the furniture parts on which the two parts forming the latch are fixed, however without departing from the sphere of the invention. [0022] The part of the latch T destined to be fixed to the furniture 57 with suitable means that are not described in detail, comprises a box or container 51 with a first groove or longitudinal cavity defining a sliding guide 60 . In the guide 60 there are the slider 52 , the helical spring 53 or another similar spring, which rests with one end on a shoulder or end of the guide and with the other end on the slider 52 , on which a shank 65 is provided to improve contact with the spring 53 . The container 51 has a cover 54 to close the open side of the guide 60 . [0023] In an advantageous embodiment part of the container is provided with an insert 50 essentially triangular in shape, which forms one side of the guide 60 , or part of one side, to facilitate manufacture and assembly. However, the insert 50 may alternatively also be eliminated to produce the container 51 in one piece. [0024] The guide 60 is inclined, with respect to the direction of application of the force F acting on the slider 52 , of an angle α, predetermined and defined according to the door or furniture part to be opened. [0025] There is provided, on the side of the guide 60 , a second groove defining a track 40 with different depths according to areas defining a path with a cam profile. [0026] The slider 52 also has a seat 71 with a rectangular plane, closed on the bottom, in which is placed a flat spring 72 bent in the shape of a V, on the outward facing side of which a ball 73 rests. The flat spring 72 thus pushes the ball 73 towards the bottom of the track 40 to make it travel along the path. A third groove 67 facilitates attachment of the spring 72 in its seat 71 . [0027] The track 40 is constituted by a longer longitudinal section 27 , the bottom of which varies in thickness and forms an inclined ramp terminating with a step 28 , which marks the limit separating it from a transverse section 29 slightly curved in the plane. The bottom of the transverse section 29 has two sections with levels 29 ′, 29 ″ slightly staggered, in the deepest of which 29 ″ a seat 30 is provided in the shape of a spherical cap. Running parallel to the section 27 is a second shorter longitudinal section 31 , which joins with the front part of the section 27 by means of a section 32 , the bottom of which is inclined, and at the end of which a short inclined ramp 33 is positioned to form a further step 34 in the connection point with the section 27 . [0028] FIG. 8 shows four positions of the latch, which show its operation between an open position and a locked position and again in an open position. The positions are indicated with the letters a), b), c), d) and also define four corresponding positions of the ball 73 along the track of the cover. Here the positions are shown as transparency views through the surface of the insert 50 . In position a) the hook 68 is in the outermost position, and therefore the hooking element 59 and the door connected to it can move freely. When the door 58 is pushed towards the closing position, the hooking element 59 knocks against the hook 68 with a force F, the component thereof parallel to the axis of the guide 60 pushes the slider 52 inside the guide 60 compressing the spring 53 to reach the position shown in FIG. 2 . [0029] During this sliding, the hook 68 engages the hooking edge 62 of the hooking element 59 , catching it. At this point as the ball 73 cannot travel along the section 32 as it is obstructed by the step 34 , it travels along the ramp 27 and passes beyond the step 28 . Here inclination of the shank of the V-shaped spring 72 pushes the ball 73 along the deepest part 29 ″ of the section 29 until it enters the seat 30 in the form of spherical cap, becoming locked in the position c). In this position the slider 52 cannot slide in the groove and the hook 68 locks the hooking element 59 , so that the furniture part remains locked in its closed position even if no external force is applied thereto. [0030] The operation to open the door or drawer is instead carried out in the following way. After a successive slight thrust in the closing direction of the door, the ball 73 is moved from the seat 30 towards the shallowest part 29 ′ of the section 29 and the spring 72 pushes it into the position d). By removing the external force on the furniture part, the helical spring 53 pushes the slider 52 towards the outside and the ball 73 travels along the sections 31 and 32 passing beyond the ramp 33 and the step 34 , returning to the initial condition a) wherein the furniture part is released. [0031] Advantageously, the hooking element can be constituted by a cavity 61 partly open towards the opposed flat surfaces so as to easily produce the hooking edge 62 , even with a moulding process. The bottom 63 constitutes the thrust element of the hook 68 when the latch is in operation, making it slide in combination with the oblique movement in the inclined direction of the angle α, until it is positioned behind the hooking edge 62 , as shown in FIGS. 2 and 6 . [0032] The cover 54 is also provided with shanks 76 suitable to be housed in corresponding holes 75 of the container 51 to allow integral assembly of the two parts. [0033] An embodiment of the latch conforming to the invention is shown in FIGS. 6 and 7 . The container 81 has an essentially hollow trapezoidal shape inside which a sliding guide 90 is placed. One of the sides of the container is open and, in the mounted position of the latch, this side is closed by a triangular insert 80 , one of the sides thereof defining a side of the guide 90 . The triangular insert 80 also has the function of resting on the furniture, with a suitable reference stop 84 . Advantageously, although not necessarily, the track 40 can be provided on one side of the triangular insert 80 . This element is suitably fixed to the container 81 by means of fixing means of known type, not shown. [0034] From the description above it is apparent that the latch device of the invention is composed of a minimum number of components, is simple to assemble and can be mounted on furniture with an operation that is not difficult even for inexperienced personnel. [0035] The particular embodiments described herein do not limit the content of this application, which covers all the embodiments of the invention defined by the claims.

Latch device composed of a container ( 51 ) in which there is a slider ( 52 ), inserted in a guide ( 60 ), controlled in translation by a spring ( 53 ) and comprising a hook ( 68 ) to catch a hooking element ( 59 ) placed on a door. A track ( 40 ), with the bottom defining the profile of a cam on one side of the guide ( 60 ), is travelled along by a ball ( 73 ) placed on the slider ( 52 ) and held pressed by a spring ( 72 ) against the bottom of the track ( 40 ) to determine the four open, closed, released and locked positions of the door according to the position of the ball in the track.

RELATED APPLICATIONS [0001] This application for letters patent is a continuation-in-part of pending application Ser. No. 09/239,126 filed on Jan. 28, 1999 (allowed). FIELD OF THE INVENTION [0002] This invention relates generally to simulated ammunition devices. More particularly, this invention relates to simulated shotgun shells, simulated rimfire rounds and simulated centerfire rounds having a realistic appearance, feel and weight. BACKGROUND AND SUMMARY OF THE INVENTION [0003] Law enforcement agencies, hunter safety organizations and others often provide firearm safety training in an effort to reduce the incidence of firearm related accidents. Safe use of shotguns, rifles and pistols is often demonstrated in such training, with such training including instruction in loading ammunition into the firearm and unloading unfired ammunition from firearm. It is undesirable to use actual live shotgun shells and rifle and pistol rounds for training in view of the inherent safety risks. In an attempt to simulate a shotgun shell, it is common for instructors to use previously fired and now empty shotgun shells, the casings of which have been re-crimped. However, empty shells do not adequately simulate a live round. Likewise, the use of empty centerfire pistol and rifle rounds is not adequate. [0004] With regard to the foregoing, the present invention is directed to a firearm ammunition simulant produced by an injection molding process. [0005] In a preferred embodiment, the ammunition simulant includes a first portion having a stud portion and a head portion. In accordance with the invention, the stud portion includes at least one engagement member having a structure extending towards or away from the stud portion, wherein the stud portion is in coaxial alignment with the head portion. The simulant also includes a second portion, and according to the invention is formed by an injection molding process. The injection molding process includes a mold and wherein injection material is injected into the mold. The injection material flows about the first portion and the engagement member of the stud portion forming a union. The ammunition simulant is formed upon hardening of the molten material and removal of the mold. The hardened mold material in the engagement member substantially prevents accidental separation of the first and second portions of the simulant. [0006] The first portion is preferably made of a metallic material, such as brass. The second portion is preferably molded from a polymeric material, such as plastic. [0007] In accordance with the invention, a method is provided for manufacturing the ammunition simulant. A solid, one piece base portion is provided having a longitudinal axis, a head which is substantially cylindrical in shape and includes a circumferential rim, and a stud including at least one engagement member extends co-axial to the longitudinal axis of the base portion. An injection mold device is provided to perform the injection molding, the device including a mold and mold material. The mold is located proximate to the base portion of ammunition simulant and a predetermined amount of mold material is injected by the device into the mold to form a mold portion. The mold portion encompasses the stud and engagement member of the base portion. Upon hardening of the mold, a union is formed between the base portion and mold portion substantially preventing accidental separation thereof. The mold is removed, providing the ammunition simulant. [0008] Simulated ammunition in accordance with the invention may be made to simulate shotgun shells, rimfire and centerfire rifle and pistol ammunition and other ammunition. [0009] To simulate a shotgun shell, the first portion is configured to resemble the case or hull of a shotgun shell and the second portion is configured to resemble the brass or base portion of a shotgun shell. [0010] To simulate rimfire ammunition, the first portion is configured to resemble the casing/bullet portion of rimfire ammunition and the second portion configured to resemble the base portion of rimfire ammunition where the primer is located. [0011] To simulate centerfire ammunition, the first portion is configured to resemble the casing/bullet portion of centerfire ammunition and the second portion configured to resemble the base portion of centerfire ammunition where the primer is located. [0012] The invention advantageously provides simulated ammunition which closely resembles the ammunition it simulates in appearance, feel and weight so as to give a realistic simulation experience. In addition, simulants in accordance with the invention are configured such that separation of the components are avoided. BRIEF DESCRIPTION OF THE DRAWINGS [0013] The above and other features and advantages of the present invention will become further known from the following detailed description considered in conjunction with the accompanying drawings in which: [0014] [0014]FIG. 1 is an elevational side view of a shotgun shell simulant in accordance with a preferred embodiment of the invention. [0015] [0015]FIG. 2 is an exploded side view of the shotgun shell simulant of FIG. 1. [0016] [0016]FIG. 3 is a cross-sectional view of a hull portion of the shell simulant of FIG. 1. [0017] [0017]FIG. 4 is a cross-sectional view of a base portion of the shell simulant of FIG. 1. [0018] [0018]FIG. 5 is an elevational side view of a shotgun shell simulant in accordance with another embodiment of the invention. [0019] [0019]FIG. 6 is an exploded side view of the shotgun shell simulant of FIG. 5. [0020] [0020]FIG. 7 is a cross-sectional view of a hull portion of the shell simulant of FIG. 5. [0021] [0021]FIG. 8 is a cross-sectional view of a base portion of the shell simulant of FIG. 5. [0022] [0022]FIG. 9 is an elevational side view of a centerfire ammunition simulant in accordance with another embodiment of the invention. [0023] [0023]FIG. 10 is an exploded side view of the simulant of FIG. 9. [0024] [0024]FIG. 11 is a cross-sectional view of a casing/bullet portion of the shell simulant of FIG. 9. [0025] [0025]FIG. 12 is a cross-sectional view of a base portion of the shell simulant of FIG. 9. [0026] [0026]FIG. 13 is an exploded side view of another embodiment of a centerfire ammunition simulant. [0027] [0027]FIG. 14 is a side view of an alternative embodiment of the shell of FIG. 5 which enables a primer to be used in combination with the simulant. [0028] [0028]FIG. 15 is a side view of a rimfire ammunition simulant in accordance with yet another embodiment of the invention. [0029] [0029]FIG. 16 is an exploded side view of the rimfire ammunition simulant of FIG. to 15 . [0030] [0030]FIG. 17 is an exploded side view of another embodiment of a rimfire ammunition simulant in accordance with the invention. [0031] [0031]FIG. 18 is an isometric view of a centerfire ammunition simulant in accordance with yet another embodiment of the invention. [0032] [0032]FIG. 19 is a side view of the centerfire ammunition simulant of FIG. 18. [0033] [0033]FIG. 20 is a side view of a portion of the centerfire ammunition simulant of FIGS. 19 and 20, and FIG. 20 a is a representative view of a mold for use in making the simulant. [0034] [0034]FIG. 20 b is a side view of a portion of a centerfire ammunition simulant in accordance with another embodiment of the invention. [0035] [0035]FIG. 21 is a side view of a shotgun shell simulant in accordance with yet another embodiment of the invention. [0036] [0036]FIG. 22 is a side view of a portion of the shotgun shell simulant of FIG. 21, and FIG. 22 a is a representative view of a mold for use in making the simulant. [0037] [0037]FIG. 23 is a side view of a rimfire ammunition simulant in accordance with yet another embodiment of the invention. [0038] [0038]FIG. 24 is a side view of a portion of the rimfire ammunition simulant of FIG. 23, and FIG. 24 a is a representative view of a mold for use in making the simulant. DETAILED DESCRIPTION [0039] With initial reference to FIG. 1, there is shown a shotgun shell simulant 10 having a case or hull portion 12 and a base portion 14 . The simulant 10 has an appearance, feel and weight which provides realistic simulation of a live or loaded shotgun shell. Advantageously, the hull portion 12 is fixedly secured to the base portion 14 in a manner that avoids accidental separation of the hull portion 12 from the base portion 14 . [0040] Avoidance of accidental separation is desirable to render the shell simulant 10 suitable for training purposes with a variety of shotguns including those having a pump action wherein shells are cycled from a magazine of a shotgun to a firing chamber and then ejected by operation of the pump action by a user. It would be undesirable for separation of the components to occur, i.e., separation of the hull and base portions, since one or both of the components could remain in the shotgun and render it unusable or unsafe for subsequent use with live ammunition. [0041] Turning to FIGS. 2, 3 and 4 , the hull portion 12 is preferably of solid, one-piece construction, preferably made of a plastic or polymeric material, most preferably nylon, using known molding techniques. The hull portion 12 is substantially cylindrical in shape to correspond in size and shape to the hull portion 12 of a shotgun shell. The hull portion 12 includes a threaded, preferably blind bore 16 co-axial to the center line of the hull portion and open at one end of the hull portion 12 for receiving a corresponding portion of the base 14 . The bore 16 may be provided, as by drilling and threading. [0042] The base portion 14 is preferably of solid, one-piece construction, preferably made of a metallic material, most preferably brass, using known milling or turning techniques. The base portion 14 includes a head 18 which is substantially cylindrical in shape and includes a circumferential rim 20 to simulate the appearance and external structure of the base portion of a shotgun shell. The base portion 14 includes a stud 22 extending co-axial to the center line of the base portion and threaded so as to be threadably receivable within the blind bore 16 of the hull portion 12 . [0043] A bore 24 is also preferably centrally provided on the head 18 opposite the stud 22 as clearance for a firing pin of a shotgun so that the shotgun may be dry fired when the simulated shell 10 is positioned within a firing chamber of the shotgun. Additionally, a resilient energy absorbing material, such as foam or a spring, may be placed within the bore 24 for dry firing purposes for avoiding damage to the firing pin of the shotgun. [0044] For the purpose of an example, the hull 12 is preferably dimensioned as set forth in Table 1 below to simulate the hull of a 12 gauge shotgun shell. It will be appreciated that the hull 12 may be provided in various dimensions to enable its use with various other gauges such as 16 gauge, 20 gauge, 28 gauge and 410 bore shotguns. TABLE 1 Dimension Inches A 1.0 length, 0.3125 inch diameter and threaded (3/8-16 thread) B 0.78 C 1.95 [0045] Likewise, the base 14 is preferably dimensioned as set forth in Table 2 below to simulate the base or brass portion of a 12 gauge shotgun shell. TABLE 2 Dimension Inches D 0.975 E 0.375 F 0.650 (3/8-16 thread) α 95° G 0.050 H 0.325 I 0.800 J 0.881 [0046] The hull portion 12 as configured above preferably has a weight of from about 13 grams to about 19 grams and the base portion 14 as configured above preferably has a weight of from about 32 grams to about 36 grams, such that the overall weight of the simulated shell is from about 47 grams to about 53 grams. It has been observed that this range substantially approximates the typical weight range of shotgun shells, whose weight generally varies from about 41 grams to about 67 grams, depending on the powder and shot charge and other characteristics of the shotgun shell. [0047] With reference now to FIG. 5, there is shown an alternate embodiment of a shotgun shell simulant 50 having a hull portion 52 and a base portion 54 . The simulant 50 also has an appearance, feel and weight which provides realistic simulation of a live shotgun shell. Advantageously, the hull portion 52 is fixedly secured to the base portion 54 in a manner that avoids accidental separation of the hull portion 52 from the base portion 54 . [0048] Turning to FIGS. 6, 7 and 8 , the hull portion 52 is preferably of solid, one-piece construction, preferably made of a plastic or polymeric material, most preferably nylon, using known molding techniques. The hull portion 52 is substantially cylindrical in shape to correspond in size and shape to the hull portion of a shotgun shell. The hull portion 52 includes a blind bore 56 co-axial to the center line of the hull portion and open at one end of the hull portion 52 for receiving a corresponding portion of the base 54 . The bore 56 may be provided, as by drilling, and is preferably of smooth bore. [0049] The base portion 54 is preferably of solid, one-piece construction, preferably made of a metallic material, most preferably brass, using known turning or milling techniques. The base portion 54 includes a head 58 which is substantially cylindrical in shape and includes a circumferential rim 60 to simulate the appearance of the base portion of a shotgun shell. The base portion 54 includes a stud 62 extending co-axial to the center line of the base portion and configured so as to be receivable within the blind bore 56 of the hull portion 52 . In this regard, the stud 62 preferably includes a plurality of projections or protrusions such as annular rings, serrations or angled barbs 63 for frictionally and mechanically engaging the sidewalls of the bore 56 of the hull portion 52 to retain the stud 62 within the bore 56 . The shell simulant 50 may be readily assembled by press-fitting the stud 62 into the bore 56 , the barbs 63 being of sufficient dimension to provide a fit sufficient to maintain the assembly of the shell 50 during use of the shell as a training device with shotguns. [0050] A blind bore 64 is also preferably centrally provided on the head 58 opposite the stud 62 as clearance for a firing pin of a shotgun so that the shotgun may be dry fired when the simulated shell 50 is positioned within the firing chamber of the shotgun. [0051] The bore 64 (and blind 24 ) is preferably blind. However, it will be understood that the bore 64 may be made contiguous through the stud 62 and communicate with the bore 56 , which may be extended to communicate with the other end of the hull portion. This would provide a continuous open bore 55 such that a live primer could be seated in the bore 64 (or bore 24 ) and fired to simulate firing of the shotgun. See, FIG. 14. [0052] For the purpose of an example, the hull 52 is preferably dimensioned as set forth in Table 3 below to simulate the hull of a 12 gauge shotgun shell. It will be appreciated that the hull 52 may be provided in various dimensions to enable its use with various other gauges such as 16 gauge, 20 gauge and 410 bore shotguns. TABLE 3 Dimension Inches K 1.0 length, 0.3125 inch diameter L 0.78 M 1.95 [0053] Likewise, the base 54 is preferably dimensioned as set forth in Table 4 below to simulate the base or brass portion of a 12 gauge shotgun shell. TABLE 4 Dimension Inches N 0.975 O 0.375 P 0.650 β 95° Q 0.050 R 0.325 S 0.800 T 0.881 [0054] The shell 50 (and the components thereof) has a weight which substantially corresponds to that of the shell 10 (and components thereof) as previously described. [0055] With reference now to FIG. 9, there is shown an alternate embodiment of an ammunition simulant 80 having a casing/bullet portion 82 and a base portion 84 . The simulant 80 also has an appearance, feel and weight which provides realistic simulation of live centerfire ammunition. Advantageously, the casing/bullet portion 82 is fixedly secured to the base portion 84 in a manner that avoids accidental separation of the casing/bullet portion 82 from the base portion 84 . [0056] Turning to FIGS. 10, 11 and 12 , the casing/bullet portion 82 is preferably of solid, one-piece construction, preferably made of a plastic or polymeric material, most preferably nylon, using known molding techniques. The casing/bullet portion 82 has a substantially cylindrical casing portion 82 a, the exterior of which corresponds in size and shape to the exterior of the casing portion of a conventional centerfire ammunition round and a bullet portion 82 b which corresponds in size and shape to the exposed portion of a bullet as seated in a conventional centerfire round. The casing/bullet portion 82 includes a preferably blind bore 86 co-axial to the center line of the casing/bullet portion and open at one end of the casing/bullet portion 82 for receiving a corresponding portion of the base 84 . The bore 86 may be provided, as by drilling, and is preferably of smooth bore. [0057] The base portion 84 is preferably solid, one-piece construction, preferably made of a metallic material, most preferably brass, using known milling and turning techniques. The base portion 84 includes a head 88 having a circumferential groove/rim 90 to simulate the appearance of the base portion of centerfire ammunition. The base portion 84 includes a stud 92 extending co-axial to the center line of the base portion and configured so as to be receivable within the bore 86 of the casing/bullet portion 82 . In this regard, the stud 92 preferably includes a plurality of protrusions such as annular rings or angled barbs 93 for frictionally and mechanically engaging the sidewalls of the bore 86 of the casing/bullet portion 82 to retain the stud 92 within the bore 86 . The shell simulant 80 may be readily assembled by press-fitting the stud 92 within the bore 86 to provide a fit sufficient to maintain the assembly of the shell 80 during use of the shell as a training device with centerfire firearms. Alternatively, as shown in FIG. 13, the simulant 80 may include a stud 92 ′ which is threaded and a bore 86 ′ having receiving threads in the manner previously described in connection with the simulant 10 . [0058] A blind bore 94 is also preferably centrally provided on the head 88 opposite the stud 92 as clearance for a firing pin of a centerfire pistol or rifle so that the pistol or rifle may be dry fired when the simulated shell 80 is positioned within the firing chamber of the firearm. The bore 94 may also be made contiguous with the bore 86 to provide a continuous bore for enabling use of a primer. [0059] For the purpose of an example, the casing/bullet 82 is preferably dimensioned as set forth in Table 5 below to simulate the casing/bullet of a 9 mm Luger centerfire pistol round. It will be appreciated that the casing/bullet 82 may be provided in various dimensions to enable its use with various other centerfire pistol and rifle calibers, e.g., 45 cal., 30-06 Springfield and the like. TABLE 5 Dimension Inches U 0.5 - depth, .221 - diameter V 0.387 W 0.545 X 0.800 Y 0.335 Z 0.325 [0060] Likewise, the base 84 is preferably dimensioned as set forth in Table 6 below to simulate the base of a 9 mm centerfire pistol round. TABLE 6 Dimension Inches AA 0.370 BB 0.160 CC 0.387 DD 0.530 EE 0.224 FF 0.187 [0061] The casing/bullet portion 82 as configured above preferably has a weight of from about 0.03 oz. to about 0.07 oz. and the base portion 84 as configured above preferably has a weight of from about 0.015 oz. to about 0.025 oz., such that the overall weight of the simulated shell is from about 0.02 oz. to about 0.03 oz. It has been observed that this range substantially approximates the typical weight of 9 mm centerfire pistol rounds, which generally weigh from about 0.03 oz. to about 0.04 oz., depending on the bullet weight. [0062] With reference now to FIG. 15, there is shown yet an alternate embodiment of an ammunition simulant 96 having a casing/bullet portion 98 and a base portion 100 The simulant 96 also has an appearance, feel and weight which provides realistic simulation of live rimfire ammunition, e.g. 22 long rifle ammunition. Advantageously, the casing/bullet portion 98 is fixedly secured to the base portion 100 in a manner that avoids accidental separation of the casing/bullet portion 98 from the base portion 100 . [0063] With additional reference to FIG. 16, the casing/bullet portion 98 is preferably of solid, one-piece construction, preferably made of a plastic or polymeric material, most preferably nylon as by injection molding. The casing/bullet portion 98 has a substantially cylindrical casing portion 102 and a bullet portion 104 . The casing/bullet portion 98 is attached to the base portion 100 to yield the simulant 96 , having a size and shape corresponding to the size and shape of a conventional rimfire round. The casing/bullet portion 98 includes a preferably blind bore 106 co-axial to the center line of the casing/bullet portion and open at one end of the casing/bullet portion 98 for receiving a corresponding portion of the base 100 The bore 106 may be provided, as by drilling, and is preferably of smooth bore. [0064] The base portion 100 is preferably solid, one-piece construction, preferably made of a metallic material, most preferably brass, as by milling. The base portion 100 includes a head 108 having a circumferential rim 110 to simulate the appearance of the base portion of rimfire ammunition. The base portion 100 includes a stud 112 extending co-axial to the center line of the base portion 100 and configured so as to be receivable within the bore 106 of the casing/bullet portion 98 . In this regard, the stud 112 preferably includes a plurality of protrusions such as annular rings or angled barbs 114 for frictionally and mechanically engaging the sidewalls of the bore 106 of the casing/bullet portion 98 to retain the stud 112 within the bore 106 . The shell simulant 96 may be readily assembled by press-fitting the stud 112 within the bore 106 to provide a fit sufficient to maintain the assembly of the shell 96 during use of the shell as a training device with rimfire firearms. [0065] Alternatively, as shown in FIG. 17, base portion 100 ′ may include a threaded stud 116 and casing/bullet portion 98 ′ include a corresponding threaded bore 118 for receiving the stud 116 . [0066] For the purpose of an example, the casing/bullets 98 and 98 ′ and base portions 100 and 100 ′ are preferably dimensioned as set forth in Table 7 below and FIG. 16, so that when assembled they simulate a 0.22 long rifle rimfire round. It will be appreciated that the casing/bullets 98 and 98 ′ and base portions 100 and 100 ′ may be provided in various dimensions to enable its use with various other rimfire pistol and rifle calibers, e.g., 0.22 short, long, 22 WMR and the like. TABLE 7 Dimension Inches A4 .375 depth, .110 - diameter B4 .221 C4 .035 D4 .325 E4 .175 F4 .095 G4 .120 H4 .270 [0067] The casing/bullet portion 98 as configured above preferably has a weight of from about ⅛oz. to about ¼oz. and the base portion 100 as configured above preferably has a weight of from about ¼oz. to about ½oz., such that the overall weight of the simulated shell is from about ⅜oz. to about ¾oz. It has been observed that this range substantially approximates the typical weight of 0.22 long rifle rimfire rounds, which generally weigh from about ½oz. to about ¾oz., depending on the bullet weight. [0068] Referring now to FIG. 18, there is shown an injection molded centerfire ammunition simulant 210 in accordance with still another embodiment of the invention. The simulant 210 includes a casing/bullet portion 212 and a base portion 214 . The injection molding process is suitable for providing a variety of simulants, including but not limited to centerfire and rimfire ammunition, and shotgun shell simulants. The simulants in accordance with the invention have an appearance, feel and weight which provides realistic simulation of live ammunition. Simulants 210 manufactured in accordance with the invention advantageously have the casing/bullet portion 212 fixedly secured to the base portion 214 in a manner that helps to avoid accidental separation of the casing/bullet portion 212 from the base portion 214 together with a permanent in-situ portion for dissipating shock on a firing pin for dry-firing purposes. [0069] Preferably, the base portion 214 of the centerfire simulant 210 is of a solid, one-piece construction, preferably made of a metallic material, most preferably brass, using known milling or turning techniques. As described further below, an injection molding process is used to fixedly secure the casing/bullet portion 212 to the base portion 214 in a manner that helps to avoid accidental separation of the casing/bullet portion 212 from the base portion 214 . [0070] With additional reference to FIG. 19, the base portion 214 includes a head 216 having a circumferential groove/rim 218 to simulate the appearance of the base portion of centerfire ammunition. The groove/rim 218 enables the extractor mechanism of the centerfire weapon to engage the simulant 210 when the simulant 210 is loaded from an ammunition cartridge into the firing chamber of the weapon. The base portion 214 includes a stud 220 that preferably extends co-axially to the center line of the base portion 214 . The stud 220 preferably has a diameter which is less than the diameter of the base portion 214 , and as described further below, the injection molded casing/bullet portion 212 encompasses the difference once the molded casing/bullet portion is injection molded to the stud 220 . [0071] The stud 220 includes a circumferential recess 222 having a width and a depth, which is preferably proximately located with respect to the head 216 . However, the circumferential recess 222 can be located at various locations along the length of the stud 220 . Moreover, more than one circumferential recess 222 can be located along the length of the stud 220 , wherein the width of each circumferential recess 222 preferably decreases as the number of circumferential recesses increases along the length of the stud 220 . As described further below, as the length of the stud 220 increases, it is preferred that more than one circumferential recess 222 be located along the length of the stud 220 . [0072] The base portion 214 also preferably includes a coaxial bore 224 having a diameter, extending therethrough. The centerfire base portion 214 is dimensioned according to the desired ammunition simulant 210 . With additional reference to FIGS. 20 and 20 b, Table 8 lists examples of dimensions (in inches) for the base portion 214 and the casing/bullet portion 212 according to various centerfire ammunition types. TABLE 8 Dimension (millimeters) A1 B1 C1 D1 E1 F1 G1 H1 J1 K1 Simulant 9 mm .462 .218 .258 .690 .335 .140 .387 .300 .500 .300 .270 1.740 .200 .250 1.948 .394 .140 .468 .300 1.957 1.045 .30-06 1.750 .200 .260 1.948 .399 .170 .468 .310 1.986 1.132 .44 mag 1.050 .200 .250 1.270 .450 .170 .508 .300 1.070 .300 [0073] The base portion 214 and its constituent elements provide a structure for adhering molten plastic to the base portion 214 , forming the casing/bullet 212 , thereby operating to replicate various ammunition types according to the specific mold used for a desired centerfire simulant 210 . The casing/bullet portion 212 has a substantially cylindrical casing portion 226 , the exterior of which corresponds in size and shape to the exterior of the casing portion of a conventional centerfire ammunition round and a bullet portion 228 which corresponds substantially in size and shape to the exposed portion of a bullet as seated in a conventional centerfire round. [0074] Once it is decided to which type or types of ammunition simulants are desired, in accordance with the invention a specific mold 229 (FIG. 20 a ) is provided for the casing/bullet portion 212 having dimensions which are substantially the same as the live ammunition to which the simulant 210 is modeled. Referring again to FIG. 19 and Table 8, various dimensions are shown for different casing/bullet types according to the centerfire ammunition simulant. [0075] The injection molding process utilizes the mold to inject a mold material such as a plastic or polymeric material, such as nylon, for example. Once a particular mold is selected according to the desired ammunition type along with the corresponding base portion 214 , the mold is placed about the base portion 214 so that the stud 220 is substantially completely encompassed by the mold abutting against the head 216 . Once the mold is in place, the injection molding equipment is preferably operated to inject molten polymeric material into the mold through an orifice provided with the mold. The molten material flows through the orifice and into the mold encompassing the stud 220 and filling in the space defined by the differing stud and head diameters. The molten material also flows into and throughout the coaxial bore 224 and circumferential recess 222 . [0076] After a predetermined amount of time, the mold material hardens and the mold is removed. Any excess mold material may be removed by grinding or cutting, leaving a simulant, such as the centerfire ammunition simulant 210 of FIG. 18. Preferably, the machining of the base portion 214 and the injection molding process is automated so that all that is required is for a user to input a desired ammunition simulant type, for example through a peripheral device, such as a handheld computer, and one or more ammunition simulants are produced according to the input. Preferably, the peripheral device includes the various dimensional characteristics of each simulant type in memory or can be input by the user. [0077] Once the mold sets, the casing/bullet portion 212 is frictionally and mechanically engaged to the base portion 214 . More specifically, a “lock” is formed between the set mold and the circumferential recess 222 , so that the casing/bullet portion 212 is substantially permanently attached to the base portion 214 , providing a fit sufficient to maintain the assembly of the casing/bullet portion 212 during use of the simulant 210 as a training device with centerfire firearms. Furthermore, a dampening mechanism is provided by the mold material encompassing the bore 224 of the base portion. More specifically, when the simulant 210 is chambered in a weapon and “dry fired”, the material in the bore 224 acts to dissipate the shock conveyed by the firing pin of the weapon, thereby substantially reducing the damage to the firing pin of the weapon. [0078] As an example, the casing/bullet portion 212 for a 9 mm simulant 210 as configured above preferably has a weight of from about 0.03 oz. to about 0.07 oz. and the base portion 214 for a 9 mm simulant 210 as configured above preferably has a weight of from about 0.015 oz. to about 0.025 oz., such that the overall weight of the simulated centerfire ammunition is from about 0.02 oz. to about 0.03 oz. It has been observed that this range substantially approximates the typical weight of 9 mm centerfire pistol rounds, which generally weigh from about 0.03 oz. to about 0.04 oz., depending on the bullet weight. [0079] Referring now to FIGS. 21 and 22, and with additional reference to Table 9, a description of an injected molded shotgun shell simulant 230 follows. The shotgun shell simulant 230 includes a base portion 232 and a hull portion 234 . The base portion 234 includes a head 236 which is substantially cylindrical in shape and includes a circumferential rim 238 to simulate the appearance and external structure of the base portion of a shotgun shell. The base portion 232 includes a stud 240 extending co-axial to the center line of the base portion 232 and includes one or more, most preferably two circumferential recesses 242 . The base portion 232 also preferably includes a bore 244 coaxially located therethrough. TABLE 9 Dimension (inches) A2 B2 C2 D2 E2 F2 G2 H2 J2 Simulant 12 gauge 1.0 .450 .540 1.450 .795 .175 .880 .600 1.825 16 gauge 1.0 .450 .500 1.450 .730 .175 .809 .550 1.850 20 gauge 1.0 .450 .320 1.450 .690 .175 .756 .380 1.850 28 gauge 1.0 .380 .260 1.450 .615 .175 .681 .440 1.850 .410 bore 1.0 .450 .260 1.450 .472 .150 .528 .300 1.790 [0080] The injection molding process is substantially the same for a shotgun shell simulant 230 as for the centerfire simulant 210 described above. The base portion 232 and its constituent elements provide a structure for adhering molten plastic to the base portion 232 , forming the hull 234 , thereby operating to replicate various shell types according to the specific mold used for a desired shotgun shell simulant 230 . The hull 234 is substantially cylindrical, the exterior of which corresponds in size and shape to the exterior of the hull portion of a conventional shotgun shell. [0081] Once it is decided to which type or types of shotgun shell simulants 230 are desired, according to the invention, a specific mold 235 (FIG. 22 a ) is provided for the hull 234 having dimensions which are substantially the same as the shotgun shell hull to which the simulant 230 is modeled. Referring again to FIG. 21 and Table 9, various dimensions are shown for different hull types according to the shotgun shell simulant 230 . [0082] As described above, the injection molding process utilizes the mold to inject a mold material such as nylon. Once a particular mold is selected according to the desired shell type along with the corresponding base portion 232 , the mold is placed about the base portion 232 so that the stud 240 is completely encompassed by the mold abutting against the head 236 . Once the mold is in place, the injection molding equipment injects molten mold material into the mold through an orifice provided with the mold. The molten material flows through the orifice and into the mold encompassing the stud 240 and filling in the space defined by the differing stud and head diameters. The molten material also flows into and throughout the coaxial bore 244 and the circumferential recesses 242 . [0083] After a predetermined amount of time, the mold material hardens and the mold is removed. Any excess mold material may be removed by grinding or cutting, leaving a simulant, such as the shotgun shell simulant of FIG. 21. Preferably, the machining of the base portion 232 and the injection molding process is automated so that all that is required is for a user to input a desired shell simulant type, for example through a peripheral device, such as a handheld computer, and one or more shell simulants are produced according to the input. Preferably, the peripheral device includes the various dimensional characteristics of each simulant type in memory or can be input by the user. [0084] According to the invention, once the mold sets, the hull 234 is frictionally and mechanically engaged to the base portion 232 . More specifically, a “lock” is formed between the set mold and the circumferential recesses 242 , so that the hull 234 is substantially permanently attached to the base portion 232 , providing a fit sufficient to maintain the assembly of the hull 234 during use of the shotgun shell simulant 230 as a training device with shotguns. Furthermore, a dampening mechanism is provided by the mold material encompassing the bore 244 of the base portion 232 . More specifically, when the shell simulant 230 is chambered in a shotgun and “dry fired”, the material in the bore 244 acts to dissipate the shock conveyed by the firing pin of the shotgun, thereby substantially reducing the damage to the firing pin. [0085] The hull 234 configured above preferably has a weight of from about 13 grams to about 19 grams and the base portion 232 as configured above preferably has a weight of from about 32 grams to about 36 grams, such that the overall weight of the shotgun shell simulant 230 is from about 47 grams to about 53 grams. It has been observed that this range substantially approximates the typical weight range of live shotgun shells, whose weight generally varies from about 41 grams to about 67 grams, depending on the powder and shot charge and other characteristics of the shotgun shell. [0086] Referring now to FIG. 23, there is shown a side view of an injection molded rimfire ammunition simulant 310 in accordance with yet another embodiment of the invention. The simulant 310 includes a casing/bullet portion 312 and a base portion 314 formed according to an injection molding process as described in greater detail below. As described above with respect to centerfire and shotgun simulants, the injection molding process is further operable to provide rimfire ammunition simulants. The rimfire simulant 310 has an appearance, feel and weight which provides realistic simulation of live rimfire ammunition. Simulants 310 manufactured in accordance with the invention advantageously have the casing/bullet portion 312 fixedly secured to the base portion 314 in a manner that helps to avoid accidental separation of the casing/bullet portion 312 from the base portion 314 . [0087] Preferably, the base portion 314 of the rimfire simulant 310 is of a solid, one-piece construction, preferably made of a metallic material, most preferably brass, using known milling or turning techniques. As described further below, an injection molding process is used to fixedly secure the casing/bullet portion 312 to the base portion 314 in a manner that helps to avoid accidental separation of the casing/bullet portion 312 from the base portion 314 . [0088] With additional reference to FIG. 24, the base portion 314 includes a head 316 having a circumferential rim 318 to simulate the appearance of the base portion of rimfire ammunition. The rim 318 enables the extractor mechanism of the rimfire weapon to engage the simulant 310 when the simulant 310 is loaded from an ammunition cartridge into the firing chamber of the weapon. The rim 318 further provides the necessary structure for the firing mechanism of a rimfire weapon to strike the rim when ‘fired’. The base portion 314 includes a stud 320 that preferably extends co-axially to the center line of the base portion 314 . The stud 320 preferably has a diameter which is less than the diameter of the base portion 314 , and to as described further below, the injection molded casing/bullet portion 312 encompasses the difference once the molded casing/bullet portion is injection molded to the stud 320 . [0089] The stud 320 includes a circumferential recess 322 having a width and a depth, which is preferably proximately located with respect to the head 316 . However, the circumferential recess 322 can be located at various locations along the length of the stud 320 . Moreover, more than one circumferential recess 322 can be located along the length of the stud 320 , wherein the width of each circumferential recess 322 preferably decreases as the number of circumferential recesses increases along the length of the stud 320 . As the length of the stud 320 increases, it is preferred that more than one circumferential recess 322 be located along the length of the stud 320 . [0090] The rimfire base portion 314 is dimensioned according to the desired ammunition simulant 310 . Table 10 lists examples of dimensions (in inches) for the base portion 314 and the casing/bullet portion 312 according to various rimfire ammunition types. TABLE 10 Dimension (millimeters) A3 B3 C3 D3 E3 F3 G3 H3 Simulant .22 short .300 .150 .119 .450 .223 .149 .270 .532 .22 long .400 .150 .119 .550 .223 .149 .270 .720 .22 long rifle .400 .150 .119 .550 .223 .149 .270 .825 .22 Mag. .850 .150 .139 1.0 .237 .159 .288 1.180 [0091] The base portion 314 and its constituent elements provide a structure for adhering molten plastic to the base portion 314 , forming the casing/bullet 312 , thereby operating to replicate various ammunition types according to the specific mold used for a desired rimfire simulant 310 . The casing/bullet portion 312 has a substantially cylindrical casing portion 326 , the exterior of which corresponds in size and shape to the exterior of the casing portion of a conventional rimfire ammunition round and a bullet portion 328 which corresponds substantially in size and shape to the exposed portion of a bullet as seated in a conventional rimfire round. [0092] Once it is decided to which type or types of rimfire ammunition simulants are desired, in accordance with the invention a specific mold 329 (FIG. 24 a ) is provided for the casing/bullet portion 312 having dimensions which are substantially the same as the live ammunition to which the simulant 310 is modeled. Referring again to FIG. 23 and Table 10, various dimensions are shown for different casing/bullet types according to the rimfire ammunition simulant. [0093] The injection molding process utilizes the mold to inject a mold material such as a plastic or polymeric material, such as nylon, for example. Once a particular mold is selected according to the desired ammunition type along with the corresponding base portion 314 , the mold is placed about the base portion 314 so that the stud 320 is substantially completely encompassed by the mold abutting against the head 316 . Once the mold is in place, the injection molding equipment is preferably operated to inject molten polymeric material into the mold through an orifice provided with the mold. The molten material flows through the orifice and into the mold encompassing the stud 320 and filling in the space defined by the differing stud and head diameters. The molten material also flows into and throughout the circumferential recess 322 . [0094] After a predetermined amount of time, the mold material hardens and the mold is removed. Any excess mold material may be removed by grinding or cutting, leaving a simulant, such as the rimfire ammunition simulant 310 of FIG. 23. Preferably, the machining of the base portion 314 and the injection molding process is automated so that all that is required is for a user to input a desired ammunition simulant type, for example through a peripheral device, such as a handheld computer, and one or more ammunition simulants are produced according to the input. Preferably, the peripheral device includes the various dimensional characteristics of each simulant type in memory or can be input by the user. [0095] According to the invention, once the mold sets, the casing/bullet portion 312 is frictionally and mechanically engaged to the base portion 314 . More specifically, a “lock” is formed between the set mold and the circumferential recess 322 , so that the casing/bullet portion 312 is substantially permanently attached to the base portion 314 , providing a fit sufficient to maintain the assembly of the casing/bullet portion 312 during use of the simulant 310 as a training device with rimfire firearms. [0096] As an example, the casing/bullet portion 314 for a .22 long rifle simulant 310 as configured above preferably has a weight of from about ⅛oz. to about ¼oz. and the base portion 314 for a .22 long rifle simulant 310 as configured above preferably has a weight of from about ¼oz. to about ½oz., such that the overall weight of the simulated rimfire ammunition is from about ⅜oz. to about ¾oz. It has been observed that this range substantially approximates the typical weight of .22 long rifle rimfire rounds, which generally weigh from about ½oz. to about ¾oz., depending on the bullet weight. [0097] Ammunition simulants in accordance with the invention are suitable for use in conventional firearms for training purposes and are compatible with the mechanisms thereof. That is, the simulants are configured so that they mechanically cooperate with magazine, feed and ejection mechanisms of conventional firearms in the same manner as ammunition does. This enables the actions of the firearms, such as the pump or lever action of a firearm, to be operated to cycle the simulants through the firearm in the same manner as live ammunition for the purpose of training. It should be noted that the examples described herein are not intended to limit the invention in any way, and furthermore, the invention is operable to provide ammunition simulants for virtually any weapon type. [0098] The foregoing description of certain embodiments of the present invention has been provided for purposes of illustration only, and it is understood that numerous modifications or alterations may be made in and to the illustrated embodiments without departing from the spirit and scope of the invention as defined in the following claims.

An ammunition simulant including a first portion having a stud portion and a head portion. The stud portion is in coaxial alignment with the head portion, wherein the stud portion includes at least one engagement member. The simulant also includes a second portion formed by an injection molding process including a mold, wherein injection material is injected into the mold and the material flows about the base portion and the engagement member of the stud portion forming a union. Whereupon the ammunition simulant is formed upon hardening of the molten material and removal of the mold.

BACKGROUND OF THE INVENTION [0001] In semiconductor device fabrication involving plasma processing to form nanometer-scale feature sizes across a large workpiece, a fundamental problem has been plasma uniformity. For example, the workpiece may be a 300 mm semiconductor wafer or a rectangular quartz mask (e.g., 152.4 mm by 152.4 mm), so that maintaining a uniform etch rate relative to nanometer-sized features across the entire area of a 300 mm diameter wafer (for example) is extremely difficult. The difficulty arises at least in part from the complexity of the process. A plasma-enhanced etch process typically involves simultaneous competing processes of deposition and etching. These processes are affected by the process gas composition, the chamber pressure, the plasma source power level (which primarily determines plasma ion density and dissociation), the plasma bias power level (which primarily determines ion bombardment energy at the workpiece surface), wafer temperature and the process gas flow pattern across the surface of the workpiece. The distribution of plasma ion density, which affects process uniformity and etch rate distribution, is itself affected by RF characteristics of the reactor chamber, such as the distribution of conductive elements, the distribution of reactances (particularly capacitances to ground) throughout the chamber, and the uniformity of gas flow to the vacuum pump. The latter poses a particular challenge because typically the vacuum pump is located at one particular location at the bottom of the pumping annulus, this location not being symmetrical relative to the either the workpiece or the chamber. All these elements involve asymmetries relative to the workpiece and the cylindrically symmetrical chamber, so that such key parameters as plasma ion distribution and/or etch rate distribution tend to be highly asymmetrical. [0002] The problem with such asymmetries is that conventional control features for adjusting the distribution of plasma etch rate (or deposition rate) across the surface of the workpiece are capable of making adjustments or corrections that are symmetrical relative to the cylindrical chamber or the workpiece or the workpiece support. (Examples of such conventional features include independently driven radially inner and outer source-power driven coils, independently supplied radially inner and outer gas injection orifice arrays in the ceiling, and the like.) Such features are, typically, incapable of completely correcting for non-uniform distribution of plasma ion density or correcting for a non-uniform distribution of etch rate across the workpiece (for example). The reason is that in practical application, such non-uniformities are asymmetrical (non-symmetrical) relative to the workpiece or to the reactor chamber. [0003] There is, therefore, a need to enable conventional control features for adjusting distribution of plasma process parameters (e.g., distribution across the workpiece of either etch rate, or etch microloading, or plasma ion density, or the like) to correct the type of asymmetrical or non-symmetrical non-uniformities that are encountered in actual plasma process environments. SUMMARY OF THE INVENTION [0004] A plasma reactor for processing a workpiece includes a process chamber having an enclosure including a ceiling and having a vertical axis of symmetry generally perpendicular to the ceiling, a workpiece support pedestal inside the chamber and generally facing the ceiling, process gas injection apparatus coupled to the chamber and a vacuum pump coupled to the chamber. The reactor further includes a plasma source power applicator overlying the ceiling and having a radially inner applicator portion and a radially outer applicator portion, and RF power apparatus coupled to the inner and outer applicator portions, and tilt apparatus supporting at least the outer applicator portion and capable of tilting at least the outer applicator portion about a radial axis perpendicular to the axis of symmetry and capable of rotating at least the outer applicator portion about the axis of symmetry. The reactor can further include elevation apparatus for changing the location of the inner and outer portions relative to one another along the vertical axis of symmetry. In a preferred embodiment, the elevation apparatus includes a lift actuator for raising and lowering the inner applicator portion along the vertical-axis of symmetry. BRIEF DESCRIPTION OF THE DRAWINGS [0005] FIG. 1 depicts a reactor of a first preferred embodiment. [0006] FIGS. 2A and 2B depict the operation of a tilt adjustment mechanism in the embodiment of FIG. 1 . [0007] FIGS. 3A, 3B and 3 C depict successive steps in the operation of the embodiment of FIG. 1 . [0008] FIGS. 4A, 4B and 4 C depict the etch rate distribution across the surface of a workpiece obtained in the respective steps of FIGS. 3A, 3B and 3 C. [0009] FIG. 5 depicts a reactor of a second preferred embodiment. [0010] FIG. 6 depicts a reactor in accordance with an alternative embodiment. [0011] FIG. 7 is a block flow diagram depicting a first method of the invention. [0012] FIG. 8 is a block flow diagram depicting a second method of the invention. DETAILED DESCRIPTION OF THE INVENTION [0013] The present invention is based upon the inventors' discovery that spatial distribution across the workpiece surface of a plasma process parameter (such as etch rate) may be transformed from an asymmetrical distribution (relative to the workpiece or to the chamber) to a more symmetrical distribution. Following such a transformation, the distribution (e.g., etch rate distribution) readily may be corrected to a uniform (or nearly uniform) distribution by employing adjustment features that operate symmetrically relative to the workpiece or relative to the chamber. In a preferred embodiment, the spatial distribution of etch rate (for example) across the workpiece is transformed from an asymmetrical distribution to a symmetrical one by tilting an overhead plasma source power applicator relative to the workpiece at such an angle that the etch rate distribution becomes symmetrical with respect to the cylindrical symmetry of the chamber or of the workpiece. For example, the etch rate, which was initially distributed in a non-symmetrical fashion, may be transformed to a center-high or center-low etch rate distribution across the workpiece. The resulting center-high or center-low etch rate distribution is then rendered perfectly uniform (or nearly uniform) by adjusting an inner portion of the overhead source power applicator relative to an outer portion of the overhead source power applicator. In a preferred embodiment, the source power applicator is an inductively coupled source power applicator consisting of (at least) a radially inner symmetrically wound conductor coil and a radially outer symmetrically wound conductor coil concentric with the inner coil. In one implementation, the adjustment of the inner coil relative to outer coil is performed by adjusting the different heights of the inner and outer coils relative to the workpiece. [0014] Referring to FIG. 1 , a plasma reactor for processing a workpiece consists of a vacuum chamber 100 defined by a cylindrical side wall 105 , a ceiling 110 and a floor 115 . A workpiece support pedestal 120 on the floor 115 can hold a workpiece 125 that is either a semiconductor wafer or a quartz mask (for example). A process gas supply 130 furnishes a process gas at a desired flow rate into the chamber 100 through gas injection devices 135 which may be provided either in the side wall 105 as shown or in the ceiling 110 . A pumping annulus 140 is defined between the workpiece support pedestal 120 and the side wall 105 , and gas is evacuated from the chamber 100 through the pumping annulus 140 by a vacuum pump 145 under the control of a throttle valve 150 . Plasma RF source power is coupled to the gases inside the chamber 100 by an RF plasma source power applicator 160 overlying the ceiling 110 . In the preferred embodiment illustrated in FIG. 1 , the source power applicator 160 consists of an inner RF coil or helical conductor winding 162 and an outer RF coil or helical conductor winding 164 , driven by respective RF source power generators 166 , 168 through respective impedance matches 170 , 172 . RF plasma bias power is coupled to the plasma by an electrode or conductive grid 175 inside the workpiece support pedestal 120 with bias power applied by an RF bias power generator 180 through an impedance match 185 . [0015] In order to adjust the distribution of plasma process non-uniformities across the surface of the workpiece 125 , the outer coil 164 can be rotated (tilted) about any selected radial axis (i.e., an axis extending through and perpendicular to the chamber's cylindrical or vertical axis of symmetry 190 ). As one advantage of this feature, we have discovered that such a rotation (or “tilt”) of the outer coil 164 , if performed about an optimum radial axis and through an optimum angle, will transform a non-symmetrical non-uniform spatial distribution of a plasma process parameter (e.g., etch rate) to a symmetrical non-uniform distribution (i.e., symmetrical about the vertical or cylindrical axis of symmetry 190 ). The “optimum” radial axis and the “optimum” angle for this tilt rotation depends upon the individual characteristics of the particular reactor chamber, among other things, and are determined empirically prior to processing of a production workpiece, e.g., by trial and error testing. [0016] Once the etch rate distribution is rendered symmetrical in this manner, its non-uniformities are readily corrected by adjusting the effect of the inner coil 162 relative to the outer coil 164 . In a preferred embodiment, this adjustment can be made by changing the height above the ceiling of one of the coils 162 , 164 relative to the other one. For this purpose, the inner coil 162 is translatable along the cylindrical axis of symmetry 190 relative to the outer coil 164 (and relative to the workpiece 125 and the entire chamber 100 ). If for example the etch rate distribution has been transformed from the typical non-symmetrical distribution to a symmetrical center-high distribution, then the non-uniformity is decreased (or eliminated) by translating the inner coil 162 vertically upward (away from the ceiling 110 ) to decrease plasma ion density over the center of the workpiece 125 . Conversely, if for example the etch rate distribution has been transformed from the typical non-symmetrical distribution to a symmetrical center-low distribution, then this non-uniformity is decreased (or eliminated) by translating the inner coil 162 vertically downward (toward the ceiling 110 ) to increase plasma ion density over the center of the workpiece 125 . [0017] In an alternative embodiment, adjustment of the effect of the inner coil 162 relative to the outer coil can be made by adjusting the relative RF power levels applied to the different coils 162 , 164 . This can be in addition to or in lieu of vertical translation of the inner coil 162 . [0018] In the preferred embodiment, the tilt rotation of the outer coil 164 is performed with very fine control over extremely small rotation angles by a pair of eccentric rings 200 , namely a top ring 202 and a bottom ring 204 , best shown in FIGS. 2A and 2B . The outer coil 164 is supported by the top ring 202 and (preferably) rotates with the top ring 202 . The upper and lower rings 202 , 204 may be thought of as having been formed from a single annular ring which has been sliced in a plane 206 that is slanted at some angle “A” relative to the horizontal. As one of the two rings 202 , 204 is rotated relative to the other about the cylindrical axis 190 , the top surface of the top ring 202 tilts from the initial level orientation of FIG. 2A to the maximum rotation of FIG. 2B . For this purpose, the two rings 202 , 204 are rotated independently of one another about the cylindrical axis 190 by respective top and bottom rotation actuators 210 , 215 . Either ring 202 , 204 may be rotated in either direction (clockwise, counter-clockwise) about the axis 190 while the other ring is held still. Or, the two rings may be rotated simultaneously in opposite rotational directions for the fastest change in tilt angle. Also, in order to adjust the orientation of the tilt direction, the two rings 202 , 204 may be rotated simultaneously in unison by the actuators 210 , 215 either before or after a desired tilt angle is established. Thus, a typical sequence may be to establish a desired tilt angle by rotating the rings 202 , 204 in opposite rotational directions until the desired tilt angle is reached, and then establishing the azimuthal direction of the tilt angle (e.g., “north”, “south”, “east” or “west” or any direction therebetween) by rotating the rings 202 , 204 simultaneously in unison—or non-simultaneously—in the same rotational direction until the tilt direction is oriented as desired. [0019] While in the preferred embodiment of FIG. 1 only the outer coil 164 is coupled to the top ring 202 , in an alternative embodiment both the inner and outer coils 162 , 164 are coupled to the top ring 202 so as to be tilted by the tilt actuators 210 , 215 . [0020] The axial (vertical) translation (up or down) of the inner coil 162 is performed by a mechanical actuator, such as the screw-drive actuator 220 that is depicted in FIG. 1 . The screw drive actuator 220 may be formed of non-conducting material and may consist of a threaded female rider 222 coupled to the inner coil 162 and a rotatable threaded screw 223 threadably engaged with the rider 222 . The screw 223 is rotated clockwise and/or counter-clockwise by a vertical translation motor 224 . Alternatively, the actuator 220 may be mounted on support structure overlying the coil 162 (not shown). [0021] In an alternative (but not preferred) embodiment, the top ring 202 supports both the inner and outer coils 162 , 164 , so that the inner and outer coils 162 , 164 tilt simultaneously together. [0022] FIGS. 3A-3C and 4 A- 4 C depict a basic process of the invention. Initially, the outer coil 164 is essentially level relative to the plane of the ceiling 110 and of the workpiece support 120 , as depicted in FIG. 3A . The etch rate distribution tends to have a non-symmetrical pattern of non-uniformity, as depicted in FIG. 4A . The outer coil 164 is then tilted ( FIG. 3B ) about a particular radial axis by a particular angle that is sufficiently optimum to transform the non-symmetrical pattern of etch rate non-uniformities of FIG. 4A to the symmetrical distribution of non-uniformities of FIG. 4B . Such an axially symmetrical distribution ( FIG. 4B ) reflects an etch rate distribution that is either center-high or center-low (for example). This non-uniformity is reduced or eliminated to produce the perfectly uniform distribution of FIG. 4C by translating the inner coil 162 either up or down along the vertical axis 190 , as indicated in FIG. 3C . Preferably, the inner coil 162 is not tilted with the outer coil 164 . However, if both coils 162 , 164 are tilted together, then the up/down translation of the inner coil 162 may be along a trajectory that is at a slight angle to the cylindrical axis 190 . [0023] In order to enable a versatile selection of all modes or combinations of all possible rotations of the top and bottom rings 162 , 164 (i.e, for tilting and/or rotation about the cylindrical axis of the outer coil 164 ) and the vertical translation of the inner coil 162 , a process controller 250 independently controls each of the rotation actuators 210 , 215 and the translation actuator 220 , as well as the RF generators 166 , 168 , 180 . [0024] FIG. 5 depicts another alternative embodiment in which the outer coil 164 is suspended from the bottom of a support 255 coupled to the top ring 202 (rather than resting on the top ring 202 as in FIG. 1 ). [0025] FIG. 6 depicts another embodiment in which an intermediate coil 260 is introduced that lies between the inner and outer coils 162 , 164 , the intermediate coil being independently driven by an RF source power generator 262 through an impedance match 264 . This embodiment may be employed in carrying out certain steps in a process of the invention in which each of the three coils 162 , 164 , 260 are driven with different RF phases (and possible the same RF frequency) to set up different maxima and minima in the RF power density distribution in the plasma generation region. This in turn is reflected in different patterns in etch rate distribution across the surface of the workpiece 125 . For example, the intermediate coil 260 may be driven 180 degrees out of phase from the inner and outer coils 162 , 164 . [0026] Returning now to FIG. 1 , while the preferred embodiments have been described with reference to apparatus and methods in which the outer coil 164 (at least) is rotated (“tilted”) about a radial axis relative to the workpiece 125 and relative to the entire chamber 100 , the converse operation could be performed to achieve similar results. Specifically, the workpiece 125 and workpiece support 120 could be tilted relative to the source power applicator 160 (and relative to the entire chamber 100 ) rather than (or in addition to) tilting the outer coil 164 . For this purpose, a pair of concentric eccentric rings 360 (identical to the rings 162 , 164 of FIG. 1 ), consisting of a top ring 362 and a bottom ring 364 , are provided under and supporting the wafer support pedestal 120 , so that the pedestal 120 can be tilted in the manner previously described with reference to the outer coil 164 . Respective top and bottom actuators 366 , 368 separately control rotation of the top and bottom rings 362 , 364 about the cylindrical axis 190 . [0027] FIG. 7 is a block flow diagram depicting a first method of the invention. The first step (block 400 ), is to tilt the RF source power applicator 160 (or at least its outer portion or coil 164 ) relative to the chamber 100 or relative to the workpiece 125 so as to transform the non-uniform distribution of a plasma process parameter (e.g., etch rate) from a non-symmetrical non-uniform distribution ( FIG. 4A ) to an axially symmetrical non-uniform distribution ( FIG. 4B ). The second step (block 402 ) is to vertically translate the inner RF source power applicator (e.g., the inner coil 162 ) relative to the outer RF source power applicator (e.g., the outer coil 164 ) or relative to the ceiling 110 or workpiece 125 , so as to transform the axially symmetrical non-uniform distribution of the process parameter (e.g., etch rate) ( FIG. 4B ) to a uniform distribution ( FIG. 4C ). [0028] FIG. 8 is a block flow diagram depicting another method of the invention that can subsume a number of different versions. The first step (block 404 ) is to rotate (tilt) the RF source power applicator 160 (or at least its outer coil 164 ) about a radial axis. In one version, this step is performed initially, i.e., prior to processing a production workpiece (block 404 a ). This step may be performed to level the source power applicator 160 (or outer coil 164 ) relative to a datum plane of the chamber 100 (block 404 a - 1 ). Or this step may be performed, as discussed previously in this specification, to make the etch rate distribution symmetrical (or at least nearly so) about the cylindrical axis 190 (block 404 a - 2 ). Or, this step may be performed to orient the plane of coil 164 relative to a plane of the workpiece 125 (block 404 a - 3 ). In another version, this step may be performed continuously during processing (block 404 b ). Alternatively, this step may be performed non-continuously or sporadically (block 404 c ). [0029] In an alternative embodiment, the purpose of the step of block 404 is to tilt the plane of the source power applicator 160 (or at least its outer coil 164 ) relative to the plane of the workpiece 125 , in which case either the coil 164 is tilted (using the rotation actuators 210 , 215 of FIG. 1 ) or the workpiece support 120 is tilted (using the rotation actuators 366 , 368 ). Or, it is possible to simultaneously tilt both the outer coil 164 and the workpiece support 120 until the desired relative orientation of the plane of one relative to the plane of the other one is achieved. As described above, the optimum orientation is one in which the distribution across the workpiece 125 of a plasma parameter such as etch rate is at least nearly symmetrical relative to the vertical axis of symmetry 190 . This enables a symmetrical adjustment in plasma distribution to render the plasma process parameter distribution at least nearly uniform. Such a symmetrical adjustment may be a change in the relative heights of the inner and outer coils 162 , 164 , or a change in the relative RF power levels applied to the two coils, for example, or a change in respective process gas flow rates to the inner and outer portions of the process region overlying the workpiece 125 . Such adjustments are carried out in some of the steps that are described below. [0030] A next step is to adjust the vertical levels of the inner and/or outer RF source power applicators 162 , 164 relative to one another or relative to the workpiece 125 (block 406 ). This step may be carried out for the purpose of transforming a cylindrically symmetrical non-uniform etch rate distribution across the workpiece 125 to a uniform distribution (or nearly uniform), as discussed above in this specification. [0031] A next step is to rotate the RF source power applicator 160 (or at least its outer coil or portion 164 ) about the vertical axis during processing (block 408 ). As mentioned previously in this specification, such a step may be carried out by rotating the two eccentric rings 202 , 204 simultaneously in unison. This step may be carried out continuously during processing (block 408 a ). Alternatively, this step may be carried out non-continuously or sporadically (block 408 b ), depending upon the desired effects during processing. Such a step may average out non-uniform effects of the source power applicator 160 across the surface of the workpiece 125 over a number of rotations during a given plasma process step. The rotation of the source power applicator 160 (or at least its outer portion 164 ) may be carried out before, during or after the tilting operation. The difference is that tilting requires relative rotational motion about the axis of symmetry 190 of the top and bottom rings 202 , 204 , whereas pure rotational motion about the axis of symmetry by the outer applicator portion 164 requires rotation in unison of the two rings 202 , 204 with no relative motion between the two rings 202 , 204 . These two modes of motion may be performed simultaneously by combining the two types of relative ring motions. Although the outer applicator portion 164 may already be tilted so that its axis of symmetry does not coincide with the vertical axis 190 , its rotational motion (when the rings 202 , 204 rotate in unison) is nevertheless defined in this specification as occurring about the vertical axis 190 . [0032] A next step (block 410 ) may be to adjust the respective levels of RF power delivered to the inner and outer coils 162 , 164 independently, in order to control the radial distribution of a plasma processing parameter (e.g., etch rate) or the effective area of the RF source power applicator 160 . As one possible example, this step may be carried out to correct a symmetrical non-uniform etch rate distribution across the workpiece surface. As such, this step may be supplementary to (or in lieu of) the vertical translation of the inner coil 162 referred to above. [0033] Another step (block 412 ) may be to adjust the RF phase differences between the different (inner/outer) source power applicator portions (e.g., multiple concentric coils 162 , 164 , 260 of FIG. 6 ) to control the radial distribution of a plasma processing parameter (e.g., etch rate). Different RF power distributions may be achieved with different phase relationships between the multiple coils, and some may be optimum for certain desired processing effects in particular instances. [0034] In a further step that is optional (block 414 of FIG. 8 ), the process gas flow rates from process gas supplies 130 , 131 to inner and outer gas inlets 130 a, 131 a (shown in FIG. 6 ) may be adjusted relative to one another to adjust plasma ion density radial distribution. The adjustments of block 406 (adjusting the relative axial locations of the inner and outer coils 162 , 164 ), block 410 (adjusting the relative RF power levels applied to the inner and outer coils 162 , 164 ) and block 414 (adjusting the relative gas flow rates to the inner and outer gas inlets 131 a, 130 a ) are all symmetrical relative to the vertical axis 190 ( FIG. 1 ) and may be used to render the etch rate distribution (for example) uniform, provided that the etch rate distribution has been transformed to a symmetrical one by the tilting step of block 404 . [0035] While the invention has been described in detail by specific reference to preferred embodiments, it is understood that variations and modifications thereof may be made without departing from the true spirit and scope of the invention.

A plasma reactor for processing a workpiece includes a process chamber having an enclosure including a ceiling and having a vertical axis of symmetry generally perpendicular to the ceiling, a workpiece support pedestal inside the chamber and generally facing the ceiling, process gas injection apparatus coupled to the chamber and a vacuum pump coupled to the chamber. The reactor further includes a plasma source power applicator overlying the ceiling and having a radially inner applicator portion and a radially outer applicator portion, and RF power apparatus coupled to the inner and outer applicator portions, and tilt apparatus supporting at least the outer applicator portion and capable of tilting at least the outer applicator portion about a radial axis perpendicular to the axis of symmetry and capable of rotating at least the outer applicator portion about the axis of symmetry. The reactor can further include elevation apparatus for changing the location of the inner and outer portions relative to one another along the vertical axis of symmetry. In a preferred embodiment, the elevation apparatus includes a lift actuator for raising and lowering the inner applicator portion along the vertical axis of symmetry.

FIELD OF THE INVENTION [0001] The invention pertains to the field of variable cam torque systems. More particularly, the invention pertains to a system and method for improving VCT closed loop response at low cam torque frequency by means of identifying cam torque direction and pausing of control updating when required. BACKGROUND OF THE INVENTION [0002] The performance of an internal combustion engine can be improved by the use of dual camshafts, one to operate the intake valves of the various cylinders of the engine and the other to operate the exhaust valves. Typically, one of such camshafts is driven by the crankshaft of the engine, through a sprocket and chain drive or a belt drive, and the other of such camshafts is driven by the first, through a second sprocket and chain drive or a second belt drive. Alternatively, both of the camshafts can be driven by a single crankshaft powered chain drive or belt drive. Engine performance in an engine with dual camshafts can be further improved, in terms of idle quality, fuel economy, reduced emissions or increased torque, by changing the positional relationship of one of the camshafts, usually the camshaft which operates the intake valves of the engine, relative to the other camshaft and relative to the crankshaft, to thereby vary the timing of the engine in terms of the operation of intake valves relative to its exhaust valves or in terms of the operation of its valves relative to the position of the crankshaft. [0003] Consideration of information disclosed by the following U.S. patents, which are all hereby incorporated by reference, is useful when exploring the background of the present invention. [0004] U.S. Pat. No. 5,002,023 describes a VCT system within the field of the invention in which the system hydraulics includes a pair of oppositely acting hydraulic cylinders with appropriate hydraulic flow elements to selectively transfer hydraulic fluid from one of the cylinders to the other, or vice versa, to thereby advance or retard the circumferential position on of a camshaft relative to a crankshaft. The control system utilizes a control valve in which the exhaustion of hydraulic fluid from one or another of the oppositely acting cylinders is permitted by moving a spool within the valve one way or another from its centered or null position. The movement of the spool occurs in response to an increase or decrease in control hydraulic pressure, PC, on one end of the spool and the relationship between the hydraulic force on such end and an oppositely direct mechanical force on the other end which results from a compression spring that acts thereon. [0005] U.S. Pat. No. 5,107,804 describes an alternate type of VCT system within the field of the invention in which the system hydraulics include a vane having lobes within an enclosed housing which replace the oppositely acting cylinders disclosed by the aforementioned U.S. Pat. No. 5,002,023. The vane is oscillatable with respect to the housing, with appropriate hydraulic flow elements to transfer hydraulic fluid within the housing from one side of a lobe to the other, or vice versa, to thereby oscillate the vane with respect to the housing in one direction or the other, an action which is effective to advance or retard the position of the camshaft relative to the crankshaft. The control system of this VCT system is identical to that divulged in U.S. Pat. No. 5,002,023, using the same type of spool valve responding to the same type of forces acting thereon. [0006] U.S. Pat. Nos. 5,172,659 and 5,184,578 both address the problems of the aforementioned types of VCT systems created by the attempt to balance the hydraulic force exerted against one end of the spool and the mechanical force exerted against the other end. The improved control system disclosed in both U.S. Pat. Nos. 5,172,659 and 5,184,578 utilizes hydraulic force on both ends of the spool. The hydraulic force on one end results from the directly applied hydraulic fluid from the engine oil gallery at full hydraulic pressure, P S . The hydraulic force on the other end of the spool results from a hydraulic cylinder or other force multiplier which acts thereon in response to system hydraulic fluid at reduced pressure, P C , from a PWM solenoid. Because the force at each of the opposed ends of the spool is hydraulic in origin, based on the same hydraulic fluid, changes in pressure or viscosity of the hydraulic fluid will be self-negating, and will not affect the centered or null position of the spool. [0007] U.S. Pat. No. 5,289,805 provides an improved VCT method which utilizes a hydraulic PWM spool position control and an advanced control method suitable for computer implementation that yields a prescribed set point tracking behavior with a high degree of robustness. [0008] In U.S. Pat. No. 5,361,735, a camshaft has a vane secured to an end for non-oscillating rotation. The camshaft also carries a timing belt driven pulley which can rotate with the camshaft but which is oscillatable with respect to the camshaft. The vane has opposed lobes which are received in opposed recesses, respectively, of the pulley. The camshaft tends to change in reaction to torque pulses which it experiences during its normal operation and it is permitted to advance or retard by selectively blocking or permitting the flow of engine oil from the recesses by controlling the position of a spool within a valve body of a control valve in response to a signal from an engine control unit. The spool is urged in a given direction by rotary linear motion translating means which is rotated by an electric motor, preferably of the stepper motor type. [0009] U.S. Pat. No. 5,497,738 shows a control system which eliminates the hydraulic force on one end of a spool resulting from directly applied hydraulic fluid from the engine oil gallery at full hydraulic pressure, Ps, utilized by previous embodiments of the VCT system. The force on the other end of the vented spool results from an electromechanical actuator, preferably of the variable force solenoid type, which acts directly upon the vented spool in response to an electronic signal issued from an engine control unit (“ECU”) which monitors various engine parameters. The ECU receives signals from sensors corresponding to camshaft and crankshaft positions and utilizes this information to calculate a relative phase angle. A closed-loop feedback system which corrects for any phase angle error is preferably employed. The use of a variable force solenoid solves the problem of sluggish dynamic response. Such a device can be designed to be as fast as the mechanical response of the spool valve, and certainly much faster than the conventional (fully hydraulic) differential pressure control system. The faster response allows the use of increased closed-loop gain, making the system less sensitive to component tolerances and operating environment. [0010] U.S. Pat. No. 5,657,725 shows a control system which utilizes engine oil pressure for actuation. The system includes A camshaft has a vane secured to an end thereof for non-oscillating rotation therewith. The camshaft also carries a housing which can rotate with the camshaft but which is oscillatable with the camshaft. The vane has opposed lobes which are received in opposed recesses, respectively, of the housing. The recesses have greater circumferential extent than the lobes to permit the vane and housing to oscillate with respect to one another, and thereby permit the camshaft to change in phase relative to a crankshaft. The camshaft tends to change direction in reaction to engine oil pressure and/or camshaft torque pulses which it experiences during its normal operation, and it is permitted to either advance or retard by selectively blocking or permitting the flow of engine oil through the return lines from the recesses by controlling the position of a spool within a spool valve body in response to a signal indicative of an engine operating condition from an engine control unit. The spool is selectively positioned by controlling hydraulic loads on its opposed end in response to a signal from an engine control unit. The vane can be biased to an extreme position to provide a counteractive force to a unidirectionally acting frictional torque experienced by the camshaft during rotation. [0011] U.S. Pat. No. 6,247,434 shows a multi-position variable camshaft timing system actuated by engine oil. Within the system, a hub is secured to a camshaft for rotation synchronous with the camshaft, and a housing circumscribes the hub and is rotatable with the hub and the camshaft and is further oscillatable with respect to the hub and the camshaft within a predetermined angle of rotation. Driving vanes are radially disposed within the housing and cooperate with an external surface on the hub, while driven vanes are radially disposed in the hub and cooperate with an internal surface of the housing. A locking device, reactive to oil pressure, prevents relative motion between the housing and the hub. A controlling device controls the oscillation of the housing relative to the hub. [0012] U.S. Pat. No. 6,250,265 shows a variable valve timing system with actuator locking for internal combustion engine. The system comprising a variable camshaft timing system comprising a camshaft with a vane secured to the camshaft for rotation with the camshaft but not for oscillation with respect to the camshaft. The vane has a circumferentially extending plurality of lobes projecting radially outwardly therefrom and is surrounded by an annular housing that has a corresponding plurality of recesses each of which receives one of the lobes and has a circumferential extent greater than the circumferential extent of the lobe received therein to permit oscillation of the housing relative to the vane and the camshaft while the housing rotates with the camshaft and the vane. Oscillation of the housing relative to the vane and the camshaft is actuated by pressurized engine oil in each of the recesses on opposed sides of the lobe therein, the oil pressure in such recess being preferably derived in part from a torque pulse in the camshaft as it rotates during its operation. An annular locking plate is positioned coaxially with the camshaft and the annular housing and is moveable relative to the annular housing along a longitudinal central axis of the camshaft between a first position, where the locking plate engages the annular housing to prevent its circumferential movement relative to the vane and a second position where circumferential movement of the annular housing relative to the vane is permitted. The locking plate is biased by a spring toward its first position and is urged away from its first position toward its second position by engine oil pressure, to which it is exposed by a passage leading through the camshaft, when engine oil pressure is sufficiently high to overcome the spring biasing force, which is the only time when it is desired to change the relative positions of the annular housing and the vane. The movement of the locking plate is controlled by an engine electronic control unit either through a closed loop control system or an open loop control system. [0013] U.S. Pat. No. 6,263,846 shows a control valve strategy for vane-type variable camshaft timing system. The strategy involves an internal combustion engine that includes a camshaft and hub secured to the camshaft for rotation therewith, where a housing circumscribes the hub and is rotatable with the hub and the camshaft, and is further oscillatable with respect to the hub and camshaft. Driving vanes are radially inwardly disposed in the housing and cooperate with the hub, while driven vanes are radially outwardly disposed in the hub to cooperate with the housing and also circumferentially alternate with the driving vanes to define circumferentially alternating advance and retard chambers. A configuration for controlling the oscillation of the housing relative to the hub includes an electronic engine control unit, and an advancing control valve that is responsive to the electronic engine control unit and that regulates engine oil pressure to and from the advance chambers. A retarding control valve responsive to the electronic engine control unit regulates engine oil pressure to and from the retard chambers. An advancing passage communicates engine oil pressure between the advancing control valve and the advance chambers, while a retarding passage communicates engine oil pressure between the retarding control valve and the retard chambers. [0014] U.S. Pat. No. 6,311,655 shows multi-position variable cam timing system having a vane-mounted locking-piston device. An internal combustion engine having a camshaft and variable camshaft timing system, wherein a rotor is secured to the camshaft and is rotatable but non-oscillatable with respect to the camshaft is discribed. A housing circumscribes the rotor, is rotatable with both the rotor and the camshaft, and is further oscillatable with respect to both the rotor and the camshaft between a fully retarded position and a fully advanced position. A locking configuration prevents relative motion between the rotor and the housing, and is mounted within either the rotor or the housing, and is respectively and releasably engageable with the other of either the rotor and the housing in the fully retarded position, the fully advanced position, and in positions therebetween. The locking device includes a locking piston having keys terminating one end thereof, and serrations mounted opposite the keys on the locking piston for interlocking the rotor to the housing. A controlling configuration controls oscillation of the rotor relative to the housing. [0015] U.S. Pat. No. 6,374,787 shows a multi-position variable camshaft timing system actuated by engine oil pressure. A hub is secured to a camshaft for rotation synchronous with the camshaft, and a housing circumscribes the hub and is rotatable with the hub and the camshaft and is further oscillatable with respect to the hub and the camshaft within a predetermined angle of rotation. Driving vanes are radially disposed within the housing and cooperate with an external surface on the hub, while driven vanes are radially disposed in the hub and cooperate with an internal surface of the housing. A locking device, reactive to oil pressure, prevents relative motion between the housing and the hub. A controlling device controls the oscillation of the housing relative to the hub. [0016] U.S. Pat. No. 6,477,999 shows a camshaft that has a vane secured to an end thereof for non-oscillating rotation therewith. The camshaft also carries a sprocket that can rotate with the camshaft but is oscillatable with respect to the camshaft. The vane has opposed lobes that are received in opposed recesses, respectively, of the sprocket. The recesses have greater circumferential extent than the lobes to permit the vane and sprocket to oscillate with respect to one another. The camshaft phase tends to change in reaction to pulses that it experiences during its normal operation, and it is permitted to change only in a given direction, either to advance or retard, by selectively blocking or permitting the flow of pressurized hydraulic fluid, preferably engine oil, from the recesses by controlling the position of a spool within a valve body of a control valve. The sprocket has a passage extending therethrough the passage extending parallel to and being spaced from a longitudinal axis of rotation of the camshaft. A pin is slidable within the passage and is resiliently urged by a spring to a position where a free end of the pin projects beyond the passage. The vane carries a plate with a pocket, which is aligned with the passage in a predetermined sprocket to camshaft orientation. The pocket receives hydraulic fluid, and when the fluid pressure is at its normal operating level, there will be sufficient pressure within the pocket to keep the free end of the pin from entering the pocket. At low levels of hydraulic pressure, however, the free end of the pin will enter the pocket and latch the camshaft and the sprocket together in a predetermined orientation. [0017] A Cam Torque Actuated (CTA) Variable Cam Timing (VCT) system does not move continuously in its commanded direction. To advance the VCT, a VCT controller commands a spool valve to move to open a one-way flow passage so that when the cam torque is positive (i.e. the cam torque is in the same direction as the cam rotation), the engine oil in the retard chamber is pushed out and flows into the advance chamber. When the cam torque becomes negative (i.e. the cam torque is in the opposite direction of the cam rotation), the oil flow can not reverse its direction, and the VCT is hydraulically locked. To retard the VCT, the VCT controller commands the spool valve to move in the opposite direction and the negative cam torque does the work. U.S. Pat. No. 5,107,805 is an example to the above. The resulting VCT motion is of a staircase fashion in that its position relating to the VCT system is incremented in a stepwise fashion. In other words, within one cam revolution VCT phaser moves only when the cam torque is in the right direction and then stops during the rest of cam revolution. [0018] Generally, a method suitable for implementation in a computer program product for VCT closed-loop control system includes an integrator, which eliminates the steady state offset between VCT commanded position (set point) and measured VCT position (phase). The method suitable for implementation in a computer program product may include a set point filter as well. The set point filter is used to smooth out any abrupt change of the set point. Gradual change of the set point makes the difference between the filtered set point and the measured phase (error zero) changes gradually too. Since the control output is directly related to error zero, the overall effect of using set point filter is a smooth control output or a closed-loop control VCT system with less overshoot. [0019] The integral action combined with a dead-time which is inherent in the cam torque actuated VCT system reduces the stability of a closed-loop control system. The dead-time is the time segment between two torque pulses, during which there is no cam torque in the right or desired direction available to drive the VCT system towards a commanded position. The lower the engine speed is and the fewer number of lobes the camshaft has, the longer this dead-time will last. On the other hand, as a general matter, the VCT controller assumes there is a constant and continuous torque available to move the VCT. The VCT controller calculates the amount of control efforts based on error zero. See U.S. Pat. No. 5,497,738 which is hereby incorporated herein by reference. As a result, the integrator keeps accumulating error zero (E0) even during the dead-time when the cam torque is in the undesirable or wrong direction and the phaser is not moving or cannot move. This in turn results in the non-stop integral action causing the controller to command more control effort than the closed-loop system needs, thus reducing the stability of the closed-loop control system. The loss of stability can be compensated by reducing the overall control gain when the cam has multiple lobes and the engine speed is high. However, the gain reduction alone is not enough when the camshaft has only few lobes, for example, less than three lobes per cam revolution, since the dead time is too long in the case of merely one or two lobes per cam revolution. [0020] Furthermore, the effect of set point filter is compromised at low engine speed as well. In case of a set point step change, while the VCT rests in most of the cam revolution due to lack of driving torque, the filtered set point values is still growing or accumulating. When the VCT waits until the torque is in the right direction and then starts to move, error zero is already very large or has accumulated to a very large value. A large error zero generates a large control signal, which can cause excessive overshoot. [0021] Therefore it is desirable to devise a method and system for identifying the cam torque direction and dead time; pausing control updating when there is no torque available such as during the dead time. SUMMARY OF THE INVENTION [0022] In a VCT system, on a cam shaft sensor wheel (cam tooth wheel) having a plurality of tooth including an index tooth which is provided to indicate when the cam torque changes its direction. [0023] In a VCT system, on a cam shaft sensor wheel (cam tooth wheel) having a plurality of tooth including an index tooth which is provided to determine dead time. [0024] A method is provided to identify the cam torque direction by using an extra tooth on a cam tooth-wheel. [0025] In a VCT system, a method is provided to reduce the VCT overshoot under closed-loop control by pausing control updates when there is no torque available to drive the VCT towards its commanded position. A computer program product incorporating the method is also provided. [0026] In a VCT system, a method is provided for identifying a direction of cam torque. The method comprising the steps of: providing a cam sensor wheel having a plurality of teeth including an index tooth formed upon the circumference of the cam sensor wheel; providing a sequence of pulses corresponding to the plurality of teeth; and using one tooth among the plurality of teeth for identifying the direction of cam torque. BRIEF DESCRIPTION OF THE DRAWING [0027] FIG. 1 shows a sensor wheel having nine (eight-plus-one) tooth and its installation on single-lobe camshaft. [0028] FIG. 2 shows the alignment between cam torque and tooth-wheel pulses for the present invention. [0029] FIG. 3 shows a known (Prior Art) VCT system with closed-loop control. [0030] FIG. 4 shows a known (Prior Art) VCT Control Law. [0031] FIG. 5 shows VCT control law with pausing control updating of the present invention. [0032] FIG. 6A shows effect of the non-improved control method. [0033] FIG. 6B shows effect of improved control method. DESCRIPTION OF THE PREFERRED EMBODIMENT [0034] FIG. 1 is a nine (eight-plus-one) tooth-wheel 100 and its installation on single-lobe camshaft. As can be seen tooth wheel 100 having eight sympatric teeth and an index tooth is provided. An additional index tooth is used in order for a cam tooth sensor to sense the same as well as all the teeth. A controller (not shown) is used to record and process the sensed tooth information. [0035] It is noted that the all the teeth on the tooth wheel may evenly or symmetrically distributed. Or on the other hand the teeth may be asymmetrically distributed. [0036] Tooth wheel 100 is mounted on a cam shaft 102 and rigidly affixed thereto and rotate along with the cam shaft 102 . Cam shaft 102 has at least one cam lobe 104 which rotates in relation to a spring retainer 106 and exerting a force upon a surface of the spring retainer 106 . A substantially equal counter force counter balances the force upon the surface by means of a valve spring 108 which is positioned upon a valve 110 in a known manner. Further, a valve guide 112 limits the movement of the valve in a known manner as well. [0037] A cam sensor 114 which is mounted stationarily in relation to the rotating tooth wheel 100 is provided for sensing the positions of the teeth on the wheel 100 . [heading-0038] Using the Index Tooth to Identify Cam Torque Direction [0039] The index tooth is provided to indicate when the cam torque changes its direction. Cam torque values and its direction vary with different cam angular positions. Ideally if there is no friction torque acting on the camshaft, the camshaft experiences negative torque when cylinder valves 110 are caused to be opened at the time when each cam lobe 104 compresses its concomitant valve spring 108 respectively. [0040] The camshaft 102 experiences positive torque during cylinder valves closing while the compressed valve springs 108 discharge their elastic kinetic energy. The zero crossing point of cam torque occurs when the angular position at which the tip of cam lobe contacts its driven part, such as the surface on the spring retainer 106 . An index tooth is provided on the wheel 100 to an otherwise equally spaced tooth-wheel 100 . As can be appreciated, an index pulse generated by the index tooth breaks the original uniform pulse distribution pattern. The VCT controller is then able to identify each individual tooth on the tooth-wheel. However, as pointed out supra, other original pulse distribution may be non-uniform (not shown). [0041] The VCT controller knows the moment of torque zero crossing when the tooth-wheel is installed in such a way such that a tooth aligns with the pick up sensor when the cam lobe tip contacts its driven parts 106 . The VCT controller also knows the direction of the torque because for a given tooth-wheel installation, each tooth and pick up sensor alignment associates with a fixed cam torque direction. [0042] Referring again to FIG. 1 the installation of an eight-tooth wheel on a single-lobe camshaft is shown in which tooth zero represents torque zero crossing. [0043] FIG. 2 shows the cam torque and the pulses generated by the pick up sensor 114 of FIG. 1 . Tooth zero indicates the starting of positive torque and the ending of negative torque. Tooth 2 indicates the ending of positive torque. [0044] In practice, the mean cam torque is always negative because of the presence of friction. Thus in the given tooth-wheel installation, tooth zero does not align precisely with the torque zero crossing point, but it is still close enough in most cases for the purpose of VCT control. By changing the alignment between tooth-wheel 100 and sensor 114 , another tooth can also represent torque zero crossing. For example, if tooth N aligns with the pick-up sensor when the cam lobe 104 tip contacts its driven parts, then the detection of tooth N indicates torque zero crossing. The VCT controller is able to know the torque direction as well in that configuration. [0045] Similarly, the VCT controller is able to identify the torque direction on any other camshaft and tooth-wheel configurations as long as an index tooth is used and the association between each tooth and the cam torque direction is known. [0046] Variable “PulseWidth” is defined as the time difference between two consecutive tooth pulses detected by the pick up sensor 114 . The following logic allows the VCT controller detects the index tooth: If 0.25*last PulseWidth<current PulseWidth<0.75*last PulseWidth Then the current tooth is the index tooth. [0049] It is pointed out that fraction values 0.25 and 0.75 are picked based on the pulse width in relation to the other parameter of the pulse train. Further, the sensitively of the sensors may also be a factor in determining the fraction values. Of course the location of the index tooth in relation to other teeth is the primary factor in determining the fraction values. [heading-0050] Pausing Control Updating When There Is No Driving Torque Available [0051] FIG. 3 shows the overall VCT closed-loop control system described in U.S. Pat. No. 5,497,738. A prior art feedback loop 10 is shown. The control objective of feedback loop 10 is to have a spool valve in a null position. In other words, the objective is to have no fluid flowing between two fluid holding chambers of a phaser (not shown) such that the VCT mechanism is at the phase angle given by a set point 12 with the spool 14 stationary in its null position. This way, the VCT mechanism is at the correct phase position and the phase rate of change is zero. A control computer program product which utilizes the dynamic state of the VCT mechanism is used to accomplish the above state. [0052] The VCT closed-loop control mechanism is achieved by measuring a camshaft phase shift θ 0 16 , and comparing the same to the desired set point 12 . The VCT mechanism is in turn adjusted so that the phaser achieves a position which is determined by the set point 12 . A control law 18 compares the set point 12 to the phase shift θ 0 16 . The compared result is used as a reference to issue commands to a solenoid 20 to position the spool 14 . This positioning of spool 14 occurs when the phase error (the difference between set point 12 and phase shift 20 ) is non-zero. [0053] The spool 14 is moved toward a first direction (e.g. right) if the phase error is negative (retard) and to a second direction (e.g. left) if the phase error is positive (advance). It is noted that the retarding with current phase measurement scheme gives a larger value, and advancing yields a small value. When the phase error is zero, the VCT phase equals the set point 12 so the spool 14 is held in the null position such that no fluid flows within the spool valve. [0054] Camshaft and crankshaft measurement pulses in the VCT system are generated by camshaft and crankshaft pulse wheels 22 and 24 , respectively. As the crankshaft (not shown) and camshaft (also not shown) rotate, wheels 22 , 24 rotate along with them. The wheels 22 , 24 possess teeth which can be sensed and measured by sensors according to measurement pulses generated by the sensors. The measurement pulses are detected by camshaft and crankshaft measurement pulse sensors 22 a and 24 a , respectively. The sensed pulses are used by a phase measurement device 26 . A measurement phase difference is then determined. The phase between a cam shaft and a crankshaft is defined as the time from successive crank-to-cam pulses, divided by the time for an entire revolution and multiplied by 360.degree. The measured phase may be expressed as θ 0 16 . This phase is then supplied to the control law 18 for reaching the desired spool position. [0055] A control law 18 of the closed-loop 10 is described in U.S. Pat. No. 5,184,578 and is hereby incorporate herein by reference. A more detailed depiction of the control law along with a set point filter 30 is shown in FIG. 4 . Measured phase 26 is subjected to the control law 18 initially at block 18 a wherein a Proportional-Integral (PI) process occurs. PI process is the sum of two sub-processes. The first sub-process includes amplification; and the second sub-process includes integration. Measured phase is further subjected to phase compensation at block 18 b , where control signal is adjusted to increase the overall control system stability before it is sent out to drive the actuator, in the instant case, a variable force solenoid. [0056] Referring to FIG. 4 , a partial depiction of the known overall VCT closed-loop control system of FIG. 1 with the addition of a set point filter 30 is shown. Specifically set point filter 30 is interposed between set point 12 and control law 18 . Further, control law 18 is shown in more detail for the digital implementation of the control law in FIG. 3 . [0057] Further, FIG. 4 gives the detailed implementation of the control law (block 18 in FIG. 3 ) in a digital control form, where the symbols are defined as follows: Z: Next control step; Zsetf: Parameter for the first-order set point; Kp: Proportional control gain; Ki: Integral control gain; Ts: Time interval between two consecutive control steps; Zlead: Phase compensator lead parameter; Zlag: Phase compensator lag parameter. [0065] Pausing control in this invention means freezing the integral action within the PI controller and freezing the filtered set point when a) the torque is not in the right direction, and b) when the phaser is outside a small neighborhood around the VCT set point. FIG. 5 shows the logic flow. [0066] Referring to FIG. 5 , similar to FIG. 4 measured phase 26 is subjected to the control law initially at block 18 a wherein a Proportional-Integral (PI) process occurs. PI process is the sum of two sub-processes. The first sub-process includes amplification; and the second sub-process includes integration. Measured phase is further subjected to phase compensation at block 18 b , where control signal is adjusted to increase the overall control system stability before it is sent out to drive the actuator, in the instant case, a variable force solenoid. Furthermore, set point 12 is provided which is subject to set point filter 30 and a filtered set point 13 results. [0067] For the present invention, in addition to the above described elements, a pausing block 200 is provided. Block 202 initializes by storing the current Integral control gain Ki to a temporary variable tempKi, and by storing Zsetf the Parameter for the first-order set point to a temporary variable tempZsetf. A determination is made at block 204 as to whether a pause in control updating is required. an example of the above determination is as follows: If the following two conditions are met, i.e. 1) the measured phase 16 is outside a predetermined neighborhood of the filtered set point 12 , and 2 ) the VCT is retarding .AND. the cam tooth counter indicates positive torque) OR. the VCT is advancing .AND. the cam tooth counter indicates negative torque. Then freeze the integrator and freeze the set point filter. [0068] In other words, when the above conditions are met, Ki is set to zero and Zsetf is set to 1 as is done in block 206 . The effect of block 206 rendering set point filter to non-filtering and the accumulating factor of block 18 a to naught. This way, the VCT system controller does not over-accumulate error signals and filtered set point does not change when there is no torque available to move the VCT phaser towards the commanded position. The above can be indicated by the orderly accumulation of cam counter 201 . [0069] However, if it is determined not to pause the system updating, the values of Ki and Zseft are restored from the temporary variables tempKi and tempZsetf in block 207 . Whether or not pausing occurs, line 208 carrying the necessary information of Ki and Zsetf is fed to block 18 a and 30 respectively for correcting functions performed therein. [0070] The implementation of the above logic for camshaft and tooth-wheel configuration shown in FIG. 1 may look as follows in computer pseudo-code. tempZsetf = Zsetf // temporarily store the value of Zsetf tempKi = Ki // temporarily store the value of Ki // Conditions for pausing control updating If (abs(e0) > threshold) AND  (((filteredSetPoint < setPoint) AND (camCounter <=2)) OR  ((filteredSetPoint > setPoint) AND (camCounter >=2)))   Zsetf = 1 // freezing set point filter   tempKi = 0 // freezing integrator Else   Zsetf = tempZsetf // resume set point filter operation   Ki = tempKi // resume integrator operation End ... in the method suitable for implementation in a computer program product to calculate the current control output using Zsetf and Ki. where, tempZsetf: a temporary storage variable to keep Zsetf; tempKi: a temporary storage variable to keep Ki; abs: math operation of absolute value; threshold: a value to specify the range of a neighborhood, e.g., three crank degrees; setPoint: VCT commanded position; filteredSetPoint: the modified value of setPoint after it passes set point filter; e0: error zero; camCounter: a variable to count the cam tooth, its value is defined in FIG. 2 . The threshold value can be any reasonably assigned value such as 3 degree, etc. [0081] The explanation of the “IF” conditions are as follows: abs(e0)>threshold [0083] The measured phase is outside the neighborhood of the filtered set point. filteredSetPoint<setPoint [0085] The VCT is commanded to retard if a larger phase value represents a more retarded position. filteredSetPoint>setPoint [0087] The VCT is commanded to advance if a smaller phase value represents a more advanced position. camCounter <=2 [0089] The cam torque is positive. This condition may be written differently based on the association between the teeth numbers and the torque directions as long as it suggests that the torque is positive. camCounter >=2 The cam torque is negative. This condition may be written differently based on the association between the teeth numbers and the torque directions as long as it suggests that the torque is negative. [0091] FIG. 6A shows the test result of the original control method suitable for implementation in a computer program product on a single-lobe camshaft VCT application. As can be seen, there is a large overshoot around the time of the 4 th second. FIG. 6B shown the test result with the implementation of the present invention. As a comparison, FIG. 6B shows no overshoot at all with the improved method suitable for implementation in a computer program product used. [0092] One embodiment of the invention is implemented as a program product for use with a vehicle computer system such as, for example, the schematics shown in FIGS. 1 and 5 and described below. The program(s) of the program product defines functions of the embodiments (including the methods described below with reference to FIG. 5 and can be contained on a variety of signal-bearing media. Illustrative signal-bearing media include, but are not limited to: (i) information permanently stored on in-circuit programmable devices like PROM, EPPOM, etc; (ii) information permanently stored on non-writable storage media (e.g., read-only memory devices within a computer such as CD-ROM disks readable by a CD-ROM drive); (iii) alterable information stored on writable storage media (e.g., floppy disks within a diskette drive or hard-disk drive); (iv) information conveyed to a computer by a communications medium, such as through a computer or telephone network, including wireless communications, or a vehicle controller of an automobile. Some embodiment specifically includes information downloaded from the Internet and other networks. Such signal-bearing media, when carrying computer-readable instructions that direct the functions of the present invention, represent embodiments of the present invention. [0093] In general, the routines executed to implement the embodiments of the invention, whether implemented as part of an operating system or a specific application, component, program, module, object, or sequence of instructions may be referred to herein as a “program”. The computer program typically is comprised of a multitude of instructions that will be translated by the native computer into a machine-readable format and hence executable instructions. Also, programs are comprised of variables and data structures that either reside locally to the program or are found in memory or on storage devices. In addition, various programs described hereinafter may be identified based upon the application for which they are implemented in a specific embodiment of the invention. However, it should be appreciated that any particular program nomenclature that follows is used merely for convenience, and thus the invention should not be limited to use solely in any specific application identified and/or implied by such nomenclature. [0094] The following are terms and concepts relating to the present invention. [0095] It is noted the hydraulic fluid or fluid referred to supra are actuating fluids. Actuating fluid is the fluid which moves the vanes in a vane phaser. Typically the actuating fluid includes engine oil, but could be separate hydraulic fluid. The VCT system of the present invention may be a Cam Torque Actuated (CTA)VCT system in which a VCT system that uses torque reversals in camshaft caused by the forces of opening and closing engine valves to move the vane. The control valve in a CTA system allows fluid flow from advance chamber to retard chamber, allowing vane to move, or stops flow, locking vane in position. The CTA phaser may also have oil input to make up for losses due to leakage, but does not use engine oil pressure to move phaser. Vane is a radial element actuating fluid acts upon, housed in chamber. A vane phaser is a phaser which is actuated by vanes moving in chambers. [0096] There may be one or more camshaft per engine. The camshaft may be driven by a belt or chain or gears or another camshaft. Lobes may exist on camshaft to push on valves. In a multiple camshaft engine, most often has one shaft for exhaust valves, one shaft for intake valves. A “V” type engine usually has two camshafts (one for each bank) or four (intake and exhaust for each bank). [0097] Chamber is defined as a space within which vane rotates. Camber may be divided into advance chamber (makes valves open sooner relative to crankshaft) and retard chamber (makes valves open later relative to crankshaft). Check valve is defined as a valve which permits fluid flow in only one direction. A closed loop is defined as a control system which changes one characteristic in response to another, then checks to see if the change was made correctly and adjusts the action to achieve the desired result (e.g. moves a valve to change phaser position in response to a command from the ECU, then checks the actual phaser position and moves valve again to correct position). Control valve is a valve which controls flow of fluid to phaser. The control valve may exist within the phaser in CTA system. Control valve may be actuated by oil pressure or solenoid. Crankshaft takes power from pistons and drives transmission and camshaft. Spool valve is defined as the control valve of spool type. Typically the spool rides in bore, connects one passage to another. Most often the spool is most often located on center axis of rotor of a phaser. [0098] Differential Pressure Control System (DPCS) is a system for moving a spool valve, which uses actuating fluid pressure on each end of the spool. One end of the spool is larger than the other, and fluid on that end is controlled (usually by a Pulse Width Modulated (PWM) valve on the oil pressure), full supply pressure is supplied to the other end of the spool (hence differential pressure). Valve Control Unit (VCU) is a control circuitry for controlling the VCT system. Typically the VCU acts in response to commands from ECU. [0099] Driven shaft is any shaft which receives power (in VCT, most often camshaft). Driving shaft is any shaft which supplies power (in VCT, most often crankshaft, but could drive one camshaft from another camshaft). ECU is Engine Control Unit that is the car's computer. Engine Oil is the oil used to lubricate engine, pressure can be tapped to actuate phaser through control valve. [0100] Housing is defined as the outer part of phaser with chambers. The outside of housing can be pulley (for timing belt), sprocket (for timing chain) or gear (for timing gear). Hydraulic fluid is any special kind of oil used in hydraulic cylinders, similar to brake fluid or power steering fluid. Hydraulic fluid is not necessarily the same as engine oil. Typically the present invention uses “actuating fluid”. Lock pin is disposed to lock a phaser in position. Usually lock pin is used when oil pressure is too low to hold phaser, as during engine start or shutdown. [0101] Oil Pressure Actuated (OPA) VCT system uses a conventional phaser, where engine oil pressure is applied to one side of the vane or the other to move the vane. [0102] Open loop is used in a control system which changes one characteristic in response to another (say, moves a valve in response to a command from the ECU) without feedback to confirm the action. [0103] Phase is defined as the relative angular position of camshaft and crankshaft (or camshaft and another camshaft, if phaser is driven by another cam). A phaser is defined as the entire part which mounts to cam. The phaser is typically made up of rotor and housing and possibly spool valve and check valves. A piston phaser is a phaser actuated by pistons in cylinders of an internal combustion engine. Rotor is the inner part of the phaser, which is attached to a cam shaft. [0104] Pulse-width Modulation (PWM) provides a varying force or pressure by changing the timing of on/off pulses of current or fluid pressure. Solenoid is an electrical actuator which uses electrical current flowing in coil to move a mechanical arm. Variable force solenoid (VFS) is a solenoid whose actuating force can be varied, usually by PWM of supply current. VFS is opposed to an on/off (all or nothing) solenoid. [0105] Sprocket is a member used with chains such as engine timing chains. Timing is defined as the relationship between the time a piston reaches a defined position (usually top dead center (TDC)) and the time something else happens. For example, in VCT or VVT systems, timing usually relates to when a valve opens or closes. Ignition timing relates to when the spark plug fires. [0106] Torsion Assist (TA) or Torque Assisted phaser is a variation on the OPA phaser, which adds a check valve in the oil supply line (i.e. a single check valve embodiment) or a check valve in the supply line to each chamber (i.e. two check valve embodiment). The check valve blocks oil pressure pulses due to torque reversals from propagating back into the oil system, and stop the vane from moving backward due to torque reversals. In the TA system, motion of the vane due to forward torque effects is permitted; hence the expression “torsion assist” is used. Graph of vane movement is step function. [0107] VCT system includes a phaser, control valve(s), control valve actuator(s) and control circuitry. Variable Cam Timing (VCT) is a process, not a thing, that refers to controlling and/or varying the angular relationship (phase) between one or more camshafts, which drive the engine's intake and/or exhaust valves. The angular relationship also includes phase relationship between cam and the crankshafts, in which the crank shaft is connected to the pistons. [0108] Variable Valve Timing (VVT) is any process which changes the valve timing. VVT could be associated with VCT, or could be achieved by varying the shape of the cam or the relationship of cam lobes to cam or valve actuators to cam or valves, or by individually controlling the valves themselves using electrical or hydraulic actuators. In other words, all VCT is VVT, but not all VVT is VCT. [0109] Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments are not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.

Known method suitable for implementation in a computer program product for VCT closed-loop control system generally includes an integrator to eliminate the steady state error. A novel method suitable for implementation in a computer program product includes a set point filter as well to reduce the closed-loop control overshoot. Low cam torque frequency can reduce the stability of a closed-loop control system when combined with the integral action, and it can also compromise the effect of set point filter. This novel method addresses these two issues by identifying the cam torque direction and pausing control updating when there is no torque available at the desired direction.

BACKGROUND OF THE INVENTION This invention relates to a caliper brake and more particularly to a new and improved pin mounted sliding caliper brake. In off-highway disc brakes there may be employed a sliding caliper with pistons only on one side of the disc or a pair of opposed pistons wherein each opposed piston controls the application of the braking forces and with the corresponding result that the braking forces are transferred to the caliper housing that supports the opposed pistons. Such caliper housing is mounted rigidly such that the operational deflections are absorbed by the moveable pistons on each side of the caliper. In this type of construction, additional stops and pins or rail mechanisms must be employed to transfer the braking forces from the brake linings to the caliper. In lieu of this construction a sliding caliper arrangement is used to lower the cost of machining for the dual piston structure where twice as many pistons are necessary to machine as well as service. The latter arrangement also requires a smaller envelope and is particularly useful where there is a space limitation because of the dual opposing piston arrangement. The sliding caliper construction is lighter in weight requiring less machining and eliminates the extra bleeding of the chambers for the dual pistons. The present invention is directed to a pin mounted sliding caliper type brake structure wherein the caliper is mounted on a round pin which guides the sliding caliper from side to side. Such construction allows the torque loading to be transferred to the vehicle chassis through the round pin mounting. An elastomeric rail snubber which is axially deformable is used to assist in the retracting of the brake pistons on release of the braking operation. Such elastomeric snubber also permits adjusting for wear of the brake lining. The structure of the instant invention permits easy access to the internal structure and permits complete access to the linings for their service and replacement in a facile manner. SUMMARY OF THE INVENTION A disc brake assembly that has a stationary support member with a portion thereof mounted adjacent to a rotor. A caliper member with friction elements mounted on opposite sides of the rotor is mounted on a pair of pin members that are parallel to the axis of the rotor. One pin member is secured to the support member while slidably connected to the caliper member. The second pin member is secured via the outside diameter of a deformable ring member to the support member and frictionally held by the inside diameter surface of the deformable ring, which deformable ring helps to restore the caliper member and its frictional elements to their normal condition upon termination of a braking operation. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a disc brake assembly and rotor disc; FIG. 2 is an enlarged front elevational view of a brake disc assembly and rotor disc taken on line 2--2 of FIG. 1 with portions broken away; FIG. 3 is a cross sectional view of the brake taken on line 3--3 of FIG. 2; FIG. 4 is a further enlarged cross sectional view of a lower portion of the brake disc assembly illustrating pin members connection to the caliper member and to an elastomeric deformable ring; FIG. 5 is a cross sectional view of a lower portion of the brake disc assembly similar to FIG. 4 but with a brake application illustration the deformable ring interconnecting the pin member to a portion of a stationary support member. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings wherein like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIGS. 1 and 2 a rotatable brake disc 9 and a Y shaped brake support 10 with diverging leg members 11 and 12 suitably mounted onto the axle housing 13 or other stationary fixed member of the chassis. The one end of leg member 11 is bifurcated as at 15 and 16 with an enlarged bore 17 and a threaded bore 18 respectively. A capped guide bolt or pin shoulder member 20 extends through bore 17 and is threadedly connected to threaded bore 18. The one end of leg members 12, which is a single member has a bore 21 and receives an elastomeric bushing 22 encased in and bonded to a thin metal cylinder 23 which is press fitted into bore 21 in a metal to metal fitting. A U-shaped floating caliper 25 or caliper member straddles the brake disc 9 and has a pair of projecting or depending housing portions 26 and 27 interconnected by a bridging portion 28 to form an integral unitary U-shaped housing. As seen in FIG. 2, the length of the bridging portion 28 is much less than the length of the projecting portions 26 and 27 to thus present extensions of portions 26 and 27 relative to the bridging portion 28. As viewed in FIG. 2, the respective upper ends of housing portions 26 and 27 have aligned bores 30 and 31 slidably receiving guide bolt or pin member 20 while the lower ends of housing portions 26 and 27 have aligned bores 32 and 33 with a bolt or pin member 35 threadedly engaging threaded bore 33 while frictionally passing through bore 36 of elastomeric bushing 22 that is mounted in the leg member 12 of stationary brake support 10. The housing portion 27 of caliper 25 has a pair of spaced bores 37 and 38 whose axes are normal to the braking planar surface of brake disc 9. A piston 39 is slidably received by each of the bores 37 and 38 with the rear end portion of such piston 39 forming an annular chamber 40 with the walls of the respective bores 37 and 38. Chamber 40 is sealed by the cooperative action of piston 39 and an annular seal 41 located in an annular groove in the respective bores 37 and 38. Each of the bores 37 and 38 are interconnected by a passageway 42, which passageway 42 is connected to an inlet pipe 43 which supplies pressurized fluid to chamber 40 from a suitable source for actuating the pistons 39. The pressurized fluid in chamber 40 is exhausted via passageway 42 via a control valve not shown in a manner old and well known in the art. The outermost ends of pistons 39, which is closest to the brake disc 9, are suitably connected to a backing plate 44, which backing plate 44 has an oblong shaped friction element 45 suitably connected thereto, for frictionally engaging the surface to be braked on brake disc 9. Located on the opposite braking surface of brake disc 9 is a friction element 48 suitably mounted on a backing plate 49 which in turn is secured to the inside wall surface of housing portion 26 of caliper 25. As best seen in FIG. 5 and 3, each backing plate 44 and 49 are narrow oblong in shape, with one end having a recess 51 which receives a portion of the guide bolt 20. As more clearly seen in FIGS. 3 and 4, the other ends of each backing plates 44 and 49 are recessed as at 53 to receive a portion of the bolt 35. Thus the guide bolt 20 and bolt 35 restrict the movement of the caliper 25 in a direction normal to the braking surface of brake disc 9. A variation on this configuration is to eliminate bore 51 and have both ends of backing plate 44 and 49 recessed as at 53 to facilitate ease of removal and replacement. On loosening of bolts 20 and 35 and sliding them sufficiently axially would permit the replacement of plates 44 and 49 along with their respective friction elements 45 and 48. Removal of bolt 20 from the threaded bore and axial movement to clear bore 51 in the backing plates would permit the pivoting of the backing plates about the guide bolt or pin member 35 to provide access to change or repair the brake pads or friction elements 45 and 48 as well as the backing plates 44 and 49 where both backing plates 44 and 49 had recesses 53 on both ends. The constructions described is a material and significant improvement over existing designs of sliding calipers as it utilizes a single sided piston where service of the brake linings is readily accessible and the mounting and hardware used to mount these structure are inexpensive and minimal to effect mounting. In addition this construction is not likely to seize and provides the unique advantage of facilitating the retraction of the piston upon release of the pressurizing fluid. This latter action is facilitated by the action of the elastomeric bushing 22. When a braking action is effected by the pressurization of chamber 40, piston 39 is moved, as shown in FIG. 5, in a direction to have friction element 45 engage the braking surface of brake disc 9, while simultaneously with this action, the caliper or caliper member 25 is moved in a direction opposite to that of piston 39 as depicted by FIG. 5, which action deforms the elastomeric bushing 22, to move the radial innermost portion to the right while the metal cylinder 23 remains stationary. Upon release of the pressurizing fluid in chamber 40, piston 39 will be retracted rightwardly as viewed in FIG. 5, while the caliper member 25 will move leftwardly. Such action or movement of caliper or caliper member 25 will be aided by the action of the deformed elastomeric bushing 22 returning to its normal position or shape. As lining wear occurs, the bushing 22 is forced to deform more until such time as it overcomes its light press fit over the lower mounting pin or bolt 35. At such time, the elastomeric bushing 22 slips on the bolt 35 and relocates to a new position on the bolt 35. The elastomeric bushing 22 then begins its deformation cycle again until such time as the wear of brake linings 45 and 48 once again slip and permit bushing 22 to relocate thereon. Various modifications are contemplated and may obviously be resorted to by those skilled in the art without departing from the described invention, as hereinafter defined by the appended claims, as only a preferred embodiment thereof has been disclosed.

A disc brake assembly comprises a caliper member that is rectilinearly movable relative to a support member via a pin member that slidably guides the caliper member while secured to the support member. A second pin member is secured to and movable with the caliper member while interconnected to the support member via a deformable elastomeric ring that aids in the return of the caliper member and the friction elements connected thereto upon termination of a braking operation.

FIELD OF THE INVENTION [0001] The present invention relates to adherent compositions, and, more particularly, to denture fixative compositions. BACKGROUND OF THE INVENTION [0002] Dentures are removable appliances that serve as a replacement for missing teeth and neighboring structures in the oral cavity. Denture fixative compositions are widely used to hold dentures in place, both while the user's mouth is at rest and particularly during mastication. Such denture fixative compositions should also perform their intended function without causing irritation to the mucosal denture surfaces. Ideal denture fixative compositions make the users of dentures confident that their dentures will remain fixed in place while functioning as intended. This is sometimes difficult to achieve particularly where dentures are not fitted perfectly or where the denture fit deteriorates over time due to denture wear or changes in the mucosal denture surfaces. [0003] Denture fixatives come in many forms including pastes, liquids, powders and aerosols. Denture fixatives may also be supplied as liners or adhesive-like strips. In all cases, it is important that good tack is achieved as soon as the dentures are properly positioned in the mouth. It is also important that the fixatives be capable of being readily spread and distributed across the denture-mucosal interface to produce sufficient adhesion to resist the stresses encountered upon mastication. Finally, the fixatives must perform well under the environmental changes typically encountered in the user's mouth such as the temperature changes experienced in drinking very hot or very cold beverages like tea, coffee or cold iced drinks or eating very hot or very cold foods. [0004] Over the years, there have been numerous improvements in denture fixative compositions. Both synthetic and natural polymers and gums have been used alone or in combination with denture fixative compositions and have been combined with various adhesives and other materials in order to achieve such improvements. For example, denture fixative compositions using alkyl vinyl ether-maleic copolymers and salts and derivatives thereof are known to provide good adhesion. U.S. Pat. No. 3,003,988 to D. P. Germann et al., issued Oct. 10, 1961, describes certain synthetic water-sensitized water-insoluble polymeric materials comprising synthetic, hydrophilic, colloidal materials in the form of mixed partial salts of lower alkyl vinyl ether-maleic anhydride-type copolymers, where the mixed partial salts and esters contain both divalent calcium and monovalent alkali cations. U.S. Pat. No. 4,373,036 to Tiang-Shing Chang et al., issued Feb. 8, 1983,relates to improved denture fixative compositions containing a dentally acceptable excipient and a fixative mixture comprising hydroxypropyl cellulose and at least one partially neutralized alkyl vinyl ether-maleic acid or anhydride copolymer, optionally partly crosslinked, a partially neutralized, optionally partly crosslinked polyacrylic acid, or a precursor combination of copolymer or polyacrylic acid, neutralizing agents, and optionally crosslinked agents or polyethylene oxide. U.S. Pat. No. 5,006,571 to Lori D. Kumar et al., issued Apr. 9, 1991, describes improved denture adhesive base compositions comprising a substantially anhydrous mixture of a mixed Na/Ca salts of methyl vinyl ether-maleic acid, sodium carboxymethylcellulose and a trivalent cation. [0005] It is therefore an important object of this invention to provide new and improved denture fixative compositions that resist the stresses at the denture-mucosal interface encountered upon mastication. [0006] It is a further object of the present invention to provide denture fixative compositions that work well immediately after application and retain their fixative properties for prolonged periods of time. [0007] Yet another object of the present invention is to provide denture fixative compositions that perform well in spite of the extreme environmental changes typically encountered in the user's mouth. [0008] Still another object of the present invention is to provide denture fixative compositions that do not cause oral mucosal irritation and further may be used to protect select areas of the gums or other oral surfaces. [0009] These and other objects of the invention will become apparent to those skilled in the art from the following detailed description of the invention. BRIEF SUMMARY OF THE INVENTION [0010] This invention relates to denture fixative compositions that can be formulated and used in the form of pastes, liquids, powders and aerosols or in making the adherent layers of liners and adhesive-like strips used as denture fixatives. Among these, the paste denture fixative compositions are preferred. [0011] In the practice of the invention, required ingredients taken from each of the three distinct categories described below are combined with adjunct ingredients including conventional vehicles, emollients, flavorants, colorants, preservatives, therapeutic components, etc. to form unique unexpectedly effective denture fixative compositions. The required ingredients include lower alkyl vinyl ether-maleic anhydride copolymers, water-insoluble and water-swelling polymers, and at least one additional adhesive material. [0012] The present composition does not cause oral mucosal irritation and-may also be used to protect oral mucosal surfaces. For example, it may be coated onto canker sores to protect those areas from irritation while healing proceeds. DETAILED DESCRIPTION OF THE INVENTION [0013] The present invention is a denture fixative composition comprising a combination of ingredients from three distinct categories that can be used in the form of pastes, liquids, powders and aerosols or in the adherent layers of liners and adhesive-like strips used as denture fixatives. Among these, the paste denture fixatives are preferred and illustrated in the formulations and examples described below. [0014] A denture fixative composition comprising a combination of these three ingredients resists the stresses at the denture-mucosal interface encountered upon mastication. This combination also works well immediately after application and retains its fixative properties for prolonged periods of time. Additionally, denture fixatives with these three ingredients perform well under the environmental changes typically encountered in the user's mouth. [0015] The three categories of ingredients that make up the fixative composition are: [0016] A. lower alkyl vinyl ether-maleic anhydride copolymers and derivatives thereof; [0017] B. water-insoluble and water-swelling polymers; and [0018] C. at least one additional adhesive material. [0019] Lower Alkyl Vinyl Ether-Maleic Anhydride Copolymers and Derivatives thereof [0020] The lower alkyl vinyl ether-maleic anhydride copolymers useful in the invention dissolve slowly in the mouth and contribute adhesive properties as they take up water. These lower alkyl vinyl ether-maleic acid polymers may be obtained by polymerizing a lower alkyl vinyl ether monomer, such as methyl vinyl ether, ethyl vinyl ether, divinyl ether, propyl vinyl ether and isobutyl vinyl ether, with maleic anhydride to yield the corresponding lower alkyl vinyl ether-maleic anhydride polymer which is readily hydrolyzable to the acid polymer. Salt forms are also commercially available and can be used. For example, salt forms of the polymers may be used in which the cationic ion is a monovalent, bivalent, or trivalent cation. Also, combinations of such salts may be used. Sodium and calcium forms of the polymer salts and mixtures of such salt forms may be used. [0021] For example, International Specialty Products of Wayne, N.J. provides GANTREZ MS-955 salt which is particularly suitable in the practice of this invention. This copolymer is a mixed sodium and calcium salt supplied as a powder. The copolymer is slowly soluble in water resulting in amber-colored solutions with high viscosity and adhesion. The divalent calcium ion lightly crosslinks the material through ion bridges to reduce its solubility and increase its cohesive strength and viscoelasticity. It is believed that the repeating units may be represented as: The approximate average molecular weight of GANTREZ MS-955 is 1,000,000 and its Brookfield viscosity (mPa. S (11.1% solids aq.)) is 700-3000. [0022] The lower alkyl vinyl ether-maleic anhydride copolymers should comprise from about 10% to about 55%, preferably from about 20% to about 40%, and yet more preferably 27% to about 31% of the dental fixative composition. [0023] Water-Insoluble and Water-Swelling Polymers [0024] This category of the above tripartite combination of ingredients is believed to be previously unknown in dental fixative applications. When the appropriate levels of water-insoluble and water-swelling polymers along with ingredients from the other two categories are used unexpectedly effective denture fixative compositions are obtained. [0025] These polymers must be water-insoluble at ambient temperatures and preferably will be water-insoluble at temperatures below about 60° C. Useful water-insoluble and water-swelling polymers include low-substituted hydroxypropyl ether of cellulose, croscarmellose sodium, carboxymethylcellulose calcium, agar and mixtures thereof. Low-substituted hydroxypropyl ether of cellulose (which may also be referred to by the chemical name cellulose, 2-hydroxypropyl ether (low-substituted) (CAS 9004-64-2)) has the structural formula: We refer to this material below as L-HPC. [0026] L-HPC is a low-substituted hydroxypropyl ether of cellulose in which a small proportion of the three hydroxyl groups contained in the β-o-glucopyranosyl ring of the cellulose is etherified with propylene oxide. L-HPC does not dissolve in water, rather it swells when wetted. [0027] Modifications of the substituent content and particle size of L-HPC cause changes in the binding characteristics as a result of subtle changes in physical properties. Therefore, the choice of the L-HPC used is of great importance. In the practice of the present invention, it has been found that the choice of L-HPC with the following properties is key: Hydroxypropyl content: about 5.0-16.0% and preferably about 10.0-12.9% by weight. Particle size: under about 200 microns [0028] Preferred L-HPC includes LH 21 , LH 31 and LH B 1 available from Shin-Etsu Chemical Company. Combinations of these preferred L-HPC ingredients or of any of the noted water-insoluble and water-swelling polymers can be used. [0029] Other water-insoluble and water-swelling polymers that may be used in the practice of the present invention include croscarmellose sodium, carboxymethylcellulose calcium and agar, as described below. [0030] Croscarmellose Sodium [0031] Croscarmellose sodium, which may also be referred to by the chemical name, cellulose, carboxymethyl ether, sodium salt, crosslinked (CAS 74811-65-7), is insoluble in water, although it swells to 4-8 times its original volume on contact with water. Croscarmellose sodium is commercially available under the trademark of Ac-Di-Sol (FMC BioPolymer, Newark, Del., USA), Primellose (DMV International GmbH, Veghel, The Netherlands) and Kiccolate ® (Asahi Kasei Chemicals Corp, Tokyo, Japan) [0032] Carboxymethylcellulose Calcium [0033] Carboxymethylcellulose calcium, which may also referred to by the chemical name, cellulose, carboxymethyl ether, calcium salt (CAS 9050-04-8), is insoluble in water, but swells to twice its volume to form suspension. Carboxymethylcellulose calcium is commercially available under the trademark of ECG 505 (Nichirin Chemical Industries Ltd., Hyogo, Japan) [0034] Agar [0035] Agar is a biopolymer found in the cell walls of seaweed, and is thought to have a structural functionality, as well as ion exchange and membrane dialysis functionality. Agar is a mixture of a neutral dominating polysaccharide called “agarose” and a charged polymer called “agaropectin”. The agarose skelton is composed of alternating D-galactopyranose units beta (1-4) and 3,6-anhdro-L-galactopyranose units liked alpha(1-3). It is insoluble in cold water but swells, and it is soluble in boiling water. The agaropectin has the same repeating units as agarose but approximately every tenth D-galactopyranose subunit occurs a substituted sulfate, methyl, pyuvic or acetyl functional group. Agar is widely commercially available and has long been used as a food ingredient. It is also currently used in the biochemical industry. [0036] The water-insoluble and water-swelling polymers should comprise from about 1 to 60%, preferably 1% to 30%, and yet more preferably from about 1% to about 13% by weight of the denture adhesive composition. Most preferably, the water-insoluble and water-swelling polymers will comprise about 4-7% by weight of the denture adhesive composition. [0037] Additional Adhesive Materials [0038] The additional adhesive materials will be chosen from the following: natural gums, synthetic polymeric gums, karaya gum, guar gum, gelatin, algin, sodium alginate, tragacanth, chitosan, polyethylene glycol, acrylamide polymers, carbopol, polyvinyl alcohol, polyvinylpyrrolidone, cellulose derivatives and mixtures thereof. Alternatively, the additional adhesive materials may be chosen from the following: methylcellulose, sodium carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyl propylmethylcellulose, carboxymethylcellulose, and mixtures thereof. [0039] Among the above additional adhesive materials, sodium carboxymethylcellulose is currently preferred. This material is a powder that when moistened becomes hydrated and tacky or gummy thereby providing additional adhesive functionality to the dental adhesive composition. The carboxymethyl cellulose gums are water-soluble, anionic long chain polymers whose properties vary to some extent depending on the number of carboxymethyl groups that are substituted per anhydroglucose unit in each cellulose molecule. Combinations of different water-soluble adhesive polymers can be used. [0040] The additional adhesive materials should comprise from about 1% to 35%, preferably from about 10% to about 30%, and yet more preferably from about 19% to about 22% by weight of the dental adhesive composition. [0041] Dental fixative creams may include as additional ingredients emollients such as petroleum jelly, mineral oil and other hydrocarbons suitable for use as emollients. The emollients may be present in the fixative composition at a level of from about 10 to about 50% by weight of the composition. [0042] The fixative composition may also include silicon dioxide at a level of about 0.1 to about 9.0% by weight of the composition. It may also include flavorants, colorants, preservatives, and mixtures thereof, as desired. [0043] Finally, the denture composition may include a therapeutic component selected from the group consisting of medically acceptable anti-bacterial agents, anti-fungal agents, anti-inflammatory agents and mixtures thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0044] FIG. 1 is a diagrammatic representation of the adhesive strength test apparatus used in Example 2 of the application; [0045] FIG. 2 is a graph comparing the adhesiveness over time of a base formulation free of water-insoluble and water-swelling polymer to three test formulations containing different L-HPC products and a second base formulation containing water soluble hydroxypropyl cellulose; [0046] FIG. 3 is a graph providing a comparison of the adhesiveness over time of a base formulation free of water-insoluble and water-swelling polymer to five formulations containing three different croscarmellose sodium, carboxymethyl cellulose-calcium and agar; [0047] FIG. 4 is a graph in which compositions of the present of invention containing L-HPC and croscarmellose-sodium were compared with the commercially available products; [0048] FIG. 5 is a graph of adhesiveness vs. time for a series of test formulations with varying levels of L-HPC. [0049] The following examples are presented in order to illustrate the present invention, but should not be taken as limiting the scope thereof. EXAMPLE 1 [0050] The efficacy of the compositions of the present invention was demonstrated in a series of tests using experimental formulations as listed below. Experimental Composition Formulation No. Components #1 #2 #3 #4 #5 Grantrez MS 955 31.5 29.5 29.5 29.5 29.5 Carboxymethyl cellulose 22.0 20.5 20.5 20.5 20.5 sodium Mineral Oil USP 24.0 22.5 22.5 22.5 22.5 White petroleum jelly 22.0 20.5 20.5 20.5 20.5 silicone dioxide 0.5 0.5 0.5 0.5 0.5 L-HPC (LH-21) 6.5 L-HPC (LH-31) 6.5 L-HPC (LH-B1) 6.5 Hydroxypropyl cellulose 6.5 (Avg. Mw. 100,000) [0051] Experimental Composition Formulation No. Components #6 #7 #8 #9 #10 Grantrez MS 955 29.5 29.5 29.5 29.5 29.5 Carboxymethyl cellulose 20.5 20.5 20.5 20.5 20.5 sodium Mineral Oil USP 22.5 22.5 22.5 22.5 22.5 White petroleum jelly 20.5 20.5 20.5 20.5 20.5 silicone dioxide 0.5 0.5 0.5 0.5 0.5 Croscarmellose sodium 6.5 (Ac-Di-Sol) Croscarmellose sodium 6.5 (Primellose) Croscarmellose sodium 6.5 (Kiccroate) Carboxymethyl cellulose- 6.5 calcium (ECG505) Agar (Avg. Mw. 700,000 to 6.5 800,000) [0052] Experimental Composition Formulation No Components #11 #12 #13 #14 #15 #16 Grantrez MS 955 31.18 30.54 30.00 29.5 28.64 27.39 Carboxymethyl cellulose 21.78 21.34 20.95 20.5 20.02 19.12 sodium Mineral Oil USP 23.76 23.28 22.85 22.5 21.28 20.87 White petroleum jelly 21.78 21.34 20.95 20.5 20.02 19.12 silicone dioxide 0.5 0.5 0.5 0.5 0.5 0.5 L-HPC (LH-31) 1.0 3.0 4.75 6.5 9.0 13.0 [0053] In selected tests, the following commercially-available and experimental dental fixative compositions were used. Product Commercially-Available Composition A Fixodent Original (P&G) B Super Polygrip Original (GSK) [0054] The adhesive strength of Formulations #1-16 was evaluated using a Tinius Olsen multipurpose test stand 10 with an upper rod 12 and lower sample plate arranged as illustrated in FIG. 1 . The rod and sample plate were suspended as shown in a water bath 16 maintained at a temperature of about 37° C. Both the rod and the sample plate were made of polymethyl methacrylate, which is a common denture base material. The diameter of the rod was 20±0.5 mm. The circular lower sample plate had a holding area 20 about 22 ±1 mm in diameter and a depth of 0.5±0.1 mm. [0055] The adhesive strength of the samples was measured by: [0056] a. first filling the holding area with the test composition with any excess material being removed. [0057] b. Both the upper rod and the filled lower plate were then attached to the Tinius Olsen multipurpose test stand. [0058] c. The upper rod was advanced to a depth of 0.25 mm below the surface of the test material in the lower sample plate. d. The filled lower sample plate with the penetrating rod were placed in the 37° C. water bath to soak the entire sample area. [0059] e. At the end of about five minutes, the upper rod was withdrawn from the sample of a rate of 0.5 mm per minute. A first adhesive force was registered by the Tinius Olsen gauge and recorded. [0060] f. Immediately following the recordal of Tinius Olsen gauge reading, the upper rod was placed in the same position at a depth of 0.25 mm below the surface of the test material in the lower sample plate, while the sample was continuously hydrated. [0061] g. The penetration and decompression (pulling) and associated Tinius Olsen gauge readings were taken until the readings approached zero force. [0062] h. The readings of the entire cycle were recorded and plotted graphically in FIGS. 2-5 . [0063] We turn now to a discussion of the test results as reflected in FIGS. 2-5 . [0064] FIG. 2 [0065] This Figure provides a comparison of the adhesiveness over time of a base composition (Formulation #1) free of water-insoluble and water-swelling polymer to test compositions using three different L-HPC products (Formulations #3, #4 and #5) and a second base formulation containing water soluble hydroxypropyl cellulose (Formulation #2) as a reference. As can be seen from the graph of adhesive force vs. time of this Figure, the formulations containing L-HPC generally have markedly higher adhesiveness overall and the superior adhesiveness is maintained over time. [0066] FIG. 3 [0067] The graph in this Figure provides a comparison of the adhesiveness over time of a base composition (Formulation #1) free of water-insoluble and water-swelling polymer to five test compositions containing different croscarmellose sodium products (Formulations #6, #7 and #8), carboxymethylcellulose-calcium (Formulation #9) and agar (Formulation #10).As can be seen from the graph of adhesive force vs. time of this Figure, the formulations containing croscarmellose sodium, carboxymethylcellulose-calcium and agar generally have better early adhesiveness and comparable adhesiveness over time to the base formulation free of water-insoluble and water-swelling polymer. [0068] FIG. 4 [0069] In this Figure, compositions of the present of invention containing L-HPC (Formulation #4) and croscarmellose-sodium (Formulation #6) were compared with the commercially available compositions, Product-A and Product-B. The results obtained demonstrate that the compositions of the present invention have substantially greater maximum adhesiveness than any of the commercial products tested and also superior adhesiveness over time as compared to Product-A and Product-B. [0070] FIG. 5 [0071] The graph in this Figure reports adhesiveness vs. time for a series of test formulations with varying levels of L-HPC. The formulations tested contain the following level of L-HPC: Formulation #. Percent by weight L-HPC 1 0 11 1.0 12 3.0 13 4.75 14 6.5 15 9.0 16 13.0 The test results show generally substantially superior adhesiveness for all of the formulations containing insoluble swelling polymers, in comparison to formulations without insoluble swelling polymer. Additionally, Formulation #16 showed superior early adhesiveness, Formulations #14 showed superior maximum adhesiveness, and all of the formulations containing L-HPC showed superior adhesiveness over time in comparison to the formulation free of water-insoluble and water-swelling polymer. [0072] If desired, denture fixatives in the forms of liquids, powders, aerosols, and even liners or adhesive-like strips may be formulated using compositions as set forth above, substituting appropriate types and levels of the adjunct ingredients required to formulate such compositions. The identity and appropriate levels of these ingredients are well-recognized by those skilled in the art. [0073] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. [0074] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the invention.

A denture fixative composition containing lower alkyl vinyl ether-maleic anhydride copolymers, water-insoluble and water-swelling polymers, and at least one additional adhesive material which can be used as a denture fixative paste, liquid, powder, aerosol, dissolving tablet, liner or adhesive-like strip.

[0001] This application claims priority from the provisional application U.S. serial No. 60/207,017, filed on May 25, 2000, the benefit of which is hereby claimed under 37 C.F.R. §1.78(a)(3). BACKGROUND OF THE INVENTION [0002] This invention is directed to combinations comprising a growth hormone secretagogue, a prodrug thereof or a pharmaceutically acceptable salt of said growth hormone secretagogue or said prodrug and an antidepressant, a prodrug thereof or a pharmaceutically acceptable salt of said antidepressant or said prodrug and to pharmaceutical compositions and kits comprising such combinations. This inventions is particularly directed to combinations wherein the antidepressant is a selective serotonin reuptake inhibitor. This invention is also directed to methods of improving the physical and/or psychological condition of a patient undergoing a medical procedure, to methods of treating musculoskeletal frailty, to methods of treating congestive heart failure and to methods of attenuating protein catabolic response after a major operation comprising administering such a combination. In particular, this invention relates to such compositions and kits that improve the cardiac function, metabolism, muscle tone and/or mental state of patients undergoing a medical procedure. The compositions and kits of this invention are also useful in treating central nervous system disorders of patients undergoing a medical procedure. [0003] Growth hormone (GH), which is secreted from the pituitary gland, stimulates growth of all tissues of the body that are capable of growing. In addition, GH is known to have the following basic effects on the metabolic process of the body: [0004] 1. Increased rate of protein synthesis in substantially all cells of the body; [0005] 2. Decreased rate of carbohydrate utilization in cells of the body; and [0006] 3. Increased mobilization of free fatty acids and use of fatty acids for energy. [0007] Deficiency in GH results in a variety of medical disorders. In children, it causes dwarfism. In adults, the consequences of acquired GH deficiency include profound reduction in lean body mass and concomitant increase in total body fat, particularly in the truncal region. Decreased skeletal and cardiac muscle mass and muscle strength lead to a significant reduction in exercise capacity. Bone density is also reduced. Administration of exogenous GH has been shown to reverse many of these metabolic changes. Additional benefits of GH therapy have included reduction in LDL cholesterol and improved psychological well-being. [0008] In cases where increased levels of GH were desired, the problem was generally solved by providing exogenous GH or by administering an agent which stimulated GH production and/or release. In either case the peptidyl nature of the compound necessitated that it be administered by injection. Initially the source of GH was the extraction of the pituitary glands of cadavers. This resulted in an expensive product, and carried with it the risk that a disease associated with the source of the pituitary gland could be transmitted to the recipient of the GH (e.g., Jacob-Creutzfeld disease). Recently, recombinant GH has become available which, while no longer carrying any risk of disease transmission, is still a very expensive product which must be given by injection or by a nasal spray. [0009] Most GH deficiencies are caused by defects in GH release, not primary defects in pituitary synthesis of GH. Therefore, an alternative strategy for normalizing serum GH levels is by stimulating its release from somatotrophs. Increasing GH secretion can be achieved by stimulating or inhibiting various neurotransmitter systems in the brain and hypothalamus. As a result, the development of synthetic GH-releasing agents to stimulate pituitary GH secretion are being pursued, and may have several advantages over expensive and inconvenient GH replacement therapy. By acting along physiologic regulatory pathways, the most desirable agents would stimulate pulsatile GH secretion, and excessive levels of GH that have been associated with the undesirable side effects of exogenous GH administration would be avoided by virtue of intact negative feedback loops. [0010] Physiologic and pharmacologic stimulators of GH secretion include arginine, L-3,4-dihydroxyphenylalanine (L-DOPA), glucagon, vasopressin, and insulin induced hypoglycemia, as well as activities such as sleep and exercise, and any activity which indirectly causes GH to be released from the pituitary by acting on the hypothalamus perhaps either to decrease somatostatin secretion or to increase the secretion of the known secretagogue GH releasing factor (GHRF) or an unknown endogenous GH-releasing hormone or all of these. [0011] Tang et al., Restoring and Maintaining Bone in Osteogenic Female Rat Skeleton: I. Changes in Bone Mass and Structure, J. Bone Mineral Research 7 (9), p1093-1104, 1992 discloses data for the lose, restore and maintain (LRM) concept, a practical approach for reversing existing osteoporosis. The LRM concept uses anabolic agents to restore bone mass and architecture (+ phase) and then switches to an agent with the established ability to maintain bone mass, to keep the new bone (+/− phase). The rat study described therein utilized PGE 2 and risedronate, a bisphosphonate, to show that most of the new cancellous and cortical bone induced by PGE 2 can be maintained for at least 60 days after discontinuing PGE 2 by administering risedronate. [0012] Antidepressants are agents used to treat affective or mood disorders and related conditions. Affective mood disorders are characterized by changes in mood as the primary clinical manifestation. Either extreme of mood may be associated with psychosis, manifested as disordered or delusional thinking and perceptions which are often incongruent with the predominant mood. Affective disorders include major depression and mania, including bipolar manic-depressive illness. Preferred classes of antidepressants include norepinephrine reuptake inhibitors (NERIs), including secondary and tertiary amine tricyclics; selective sertraline reuptake inhibitors; combined NERI/SSRIs; monoamine oxidase (MAO) inhibitors; and atypical antidepressants. NERIs potentiate the actions of biogenic amines by blocking their major means of physiological inactivation, which involves transport or reuptake into nerve terminals, and specifically, agents which block the reuptake of norepinephrine into said nerve terminals. The term selective serotonin reuptake inhibitor refers to a compound which inhibits the reuptake of serotonin by afferent neurons. Combined NERI/SSRIs block the reuptake of both serotonin and norepinephrine by afferent neurons. Monoamine oxidase inhibitors are compounds which inhibit monoamine oxidase, for example by blocking the metabolic deamination of a variety of monoamines by mitochondrial monoamine oxidase. SUMMARY OF THE INVENTION [0013] This invention is directed to combinations comprising a growth hormone secretagogue (GHS), a prodrug thereof or a pharmaceutically acceptable salt of said GHS or said prodrug and an antidepressant, a prodrug thereof or a pharmaceutically acceptable salt of said antidepressant or said prodrug. This invention is also directed to pharmaceutical compositions, methods and kits comprising said combination, as described below. Preferred classes of antidepressants for use in the combinations, pharmaceutical compositions, kits and methods of this invention are norepinephrine reuptake inhibitors (NERIs), selective serotonin reuptake inhibitors (SSRIs), monoamine oxidase inhibitors (MAO inhibitors), combined NERI/SSRIs, and atypical antidepressants, prodrugs of said antidepressants and pharmaceutically acceptable salts of said antidepressants and said prodrugs. [0014] This invention is particularly directed to pharmaceutical compositions comprising a GHS, a prodrug thereof or a pharmaceutically acceptable salt of said GHS or said prodrug; a SSRI, a prodrug thereof or a pharmaceutically acceptable salt of said SSRI or said prodrug; and a pharmaceutically acceptable carrier, vehicle or diluent. [0015] NERIs are especially preferred. NERIs may be either secondary amine tricyclic compounds or tertiary amine tricyclic compounds. Particularly preferred secondary amine tricyclic NERI compounds include, but are not limited to, amoxapine, desipramine, maprotiline, nortriptyline and protriptyline, prodrugs of said secondary amine tricyclic NERIs and pharmaceutically acceptable salts of said secondary amine tricyclic NERIs and said prodrugs. Particularly preferred tertiary amine tricyclic NERI compounds include, but are not limited to, amitryptiline, clomipramine, doxepin, imipramine and trimipramine, prodrugs of said tertiary amine tricyclic NERIs and pharmaceutically acceptable salts of said tertiary amine tricyclic NERIs and said prodrugs. [0016] SSRIs are also especially preferred. Particularly preferred SSRIs include, but are not limited to, citalopram, femoxetine, fluoxetine, fluvoxamine, indalpine, indeloxazine, milnacipran, paroxetine, sertraline, sibutramine and zimeldine, prodrugs of said SSRIs and pharmaceutically acceptable salts of said SSRIs and said prodrugs. Sertraline and fluoxetine, and pharmaceutically acceptable salts thereof, are more particularly preferred. Sertraline hydrochloride is most preferred. [0017] Combined NERI/SSRIs are also especially preferred. A particularly preferred combined NERI/SSRI is venlafaxine, prodrugs thereof and pharmaceutically acceptable salts of venlafaxine and of said prodrugs. Other combined NERI/SSRIs are also within the scope of the combinations, pharmaceutical compositions, kits and methods of this invention. [0018] Monoamine oxidase (MAO) inhibitors are also especially preferred. Particularly preferred MAO inhibitors include, but are not limited to, phenelzine, tranylcypromine and selegiline, prodrugs thereof and pharmaceutically acceptable salts of said MAO inhibitors and of said prodrugs. [0019] Atypical antidepressants are also especially preferred. Particularly preferred atypical antidepressants include, but are not limited to, bupropion, nefazodone and trazodone, prodrugs thereof and pharmaceutically acceptable salts of said atypical antidepressants and of said prodrugs. [0020] In the combinations, pharmaceutical compositions, methods and kits of this invention, it is preferred that said GHS is a compound of the formula I: [0021] or a stereoisomeric mixture thereof, diastereomerically enriched, diastereomerically pure, enantiomerically enriched or enantiomerically pure isomer thereof, [0022] wherein: [0023] HET is a heterocyclic moiety selected from the group consisting of [0024] d is 0, 1 or 2; [0025] e is 1 or 2; [0026] f is 0 or 1; [0027] n and w are 0, 1 or 2, provided that n and w cannot both be 0 at the same time; [0028] Y 2 is oxygen or sulfur; [0029] A is a divalent radical, where the left hand side of the radical as shown below is connected to C″ and the right hand side of the radical as shown below is connected to C′, selected from the group consisting of [0030] —NR 2 —C(O)—NR 2 —, —NR 2 —S(O) 2 —NR 2 —, —O—C(O)—NR 2 —, —NR 2 —C(O)—O—, —C(O)—NR 2 —C(O)—, —C(O)—NR 2 —C(R 9 R 10 )—, —C(R 9 R 10 )—NR 2 —C(O)—, —C(R 9 R 10 )—C(R 9 R 10 )—C(R 9 R 10 )—, —S(O) 2 —C(R 9 R 10 )—C(R 9 R 10 )—, —C(R 9 R 10 )—O—C(O)—, —C(R 9 R 10 )—O—C(R 9 R 10 )—, —NR 2 —C(O)—C(R 9 R 10 )—, —O—C(O)—C(R 9 R 10 )—, —C(R 9 R 10 )—C(O)—NR 2 —, —C(O)—NR 2 —C(O)—, —C(R 9 R 10 )—C(O)—O—, —C(O)—NR 2 —C(R 9 R 10 )—C(R 9 R 10 )—, —C(O)—O—C(R 9 R 10 )—, —C(R 9 R 10 )—C(R 9 R 10 )—C(R 9 R 10 )—C(R 9 R 10 )—, —S(O) 2 —NR 2 —C(R 9 R 1 )—C(R 9 R 10 )—, —C(R 9 R 10 )—C(R 9 R 10 )—NR 2 —C(O)—, —C(R 9 R 10 )—C(R 9 R 10 )—O—C(O)—, —NR 2 —C(O)—C(R 9 R 10 )—C(R 9 R 10 )—, —NR 2 —S(O) 2 —C(R 9 R 10 )—C(R 9 R 10 )—, —O—C(O)—C(R 9 R 10 )—C(R 9 R 10 )—, —C(R 9 R 1 0 )—C(R 9 R 10 )—C(O)—NR 2 , —C(R 9 R 10 )—C(R 9 R 10 )—C(O)—, —C(R 9 R 10 )—NR 2 —C(O)—, —C(R 9 R 10 )—O—C(O)—NR 2 —, —C(R 9 R 10 )—NR 2 —C(O)—NR 2 —, —NR 2 —C(O)—O—C(R 9 R 10 )—, —NR2—C(O)—NR 2 —C(R 9 R 10 )—, —NR 2 —S(O) 2 —NR 2 —C(R 9 R 10 )—, —O—C(O)—NR 2 —C(R 9 R 10 )—, —C(O)—N═C(R 1 )—NR 2 —, —C(O)—NR 2 —C(R 1 1 )═N—, —C(R 9 R 10 )—NR 2 —C(R 9 R 10 )—, —NR 2 C(R 9 R 10 )—, —NR 2 —C(R 9 R 10 )—C(R 9 R 10 )—, —C(O)—O—C(R 9 R 10 )—C(R 9 R 10 )—, —NR 2 —C(R 1 1 )=N—C(O)—, —C(R 9 R 10 )—C(R 9 R 10 )—N(R 12 ) —C(R 9 R 10 )—NR 12 —, —N═C(R 1 1 )—NR 2 —C(O)—, —C(R 9 R 1 )—C(R 9 R 10 )—NR 2 —S(O) 2 —, —C(R 9 R 10 )—C(R 9 R 10 )—S(O) 2 —NR 2 —, —C(R 9 R 10 )—C(R 9 R 10 )—C(O)—O—, —C(R 9 R 10 )—S(O) 2 —C(R 9 R )—, —C(R 9 R 10 )—C(R 9 R 10 )—S(O) 2 —, —O—C(R 9 R 10 )—C(R 9 R 10 )—, —C(R 9 R 10 )—C(R 9 R 10 )—O—, —C(R 9 R 10 )—C(O)—C(R 9 R 10 )—, —C(O)—C(R 9 R)—C(R 9 R 10 )— and —C(R 9 R 10 )—NR 2 S(O) 2 —NR 2 ; [0031] Q is a covalent bond or CH 2 ; [0032] W is CH or N; [0033] X is CR 9 R 10 , C═CH 2 or C═O; [0034] Y is CR 9 R 10 , 0 or NR 2 ; [0035] Z is C═O, C═S or S(O) 2 ; [0036] G 1 is hydrogen, halo, hydroxy, nitro, amino, cyano, phenyl, carboxyl, —CONH 2 , —(C 1 -C 4 )alkyl optionally independently substituted with one or more phenyl, one or more halogens or one or more hydroxy groups, —(C 1 -C 4 )alkoxy optionally independently substituted with one or more phenyl, one or more halogens or one or more hydroxy groups, —(C 1 -C 4 )alkylthio, phenoxy, —COO(C 1 -C 4 )alkyl, N, N-di—(C 1 -C 4 )alkylamino, —(C 2 -C 6 )alkenyl optionally independently substituted with one or more phenyl, one or more halogens or one or more hydroxy groups, —(C 2 -C 6 )alkynyl optionally independently substituted with one or more phenyl, one or more halogens or one or more hydroxy groups, —(C 3 -C 6 )cycloalkyl optionally independently substituted with one or more (C 1 -C 4 )alkyl groups, one or more halogens or one or more hydroxy groups, —(C 1 -C 4 )alkylamino carbonyl or di—(C 1 -C 4 )alkylamino carbonyl; [0037] G 2 and G 3 are each independently selected from the group consisting of hydrogen, halo, hydroxy, —(C 1 -C 4 )alkyl optionally independently substituted with one to three halo groups and —(C 1 -C 4 )alkoxy optionally independently substituted with one to three halo groups; [0038] R 1 is hydrogen, —CN, —(CH 2 ) q N(X 6 )C(O)X 6 , —(CH 2 ) q N(X 6 )C(O)(CH 2 ) t -A 1 , —(CH 2 ) q N(X 6 )S(O) 2 (CH 2 ) t A 1 , (CH 2 ) q N (X 6 )S(O) 2 X 6 , (CH 2 ) q N(X 6 )C(O)N(X 6 )(CH 2 ) t A 1 , —(CH 2 ) q N(X 6 )C(O)N(X 6 )(X 6 ), (CH 2 ) q C(O)N(X 6 )(X 6 ), (CH 2 ) q C(O)N(X 6 )(CH 2 ) t A 1 , —(CH 2 ) q C(O)OX 6 , (CH 2 ) q C(O)O(CH 2 ) t -A 1 X, (CH 2 ) q OX 6 , (CH 2 ) q OC(O)X 6 , —(CH 2 ) q OC(O)(CH 2 -A 1 , —(CH 2 ) q OC(O)N(X 6 )(CH 2 ) t Al, —(CH 2 ) q OC(O)N(X 6 )(X 6 ), —(CH 2 ) q C(O)X 6 , (CH 2 ) q C(O)(CH 2 ) t A 1 X, (CH 2 ) q N(X 6 )C(O)OX 6 , —(CH 2 ) q N(X 6 )S(O) 2 N(X 6 )(X 6 ), (CH 2 ) q S(O) m X 6 , (CH 2 ) q S(O)m(CH 2 ) t A 1 , —(C 1 -C 10 )alkyl, —(CH 2 ) t -A 1 , —(CH 2 ) q —(C 3 -C 7 )cycloalkyl, (CH 2 ) q -Y 1 —(C 1 -C 6 )alkyl, —(CH 2 ) q —Y 1 —(CH 2 ) t -A 1 or —(CH 2 ) q —Y 1 —(CH 2 ) t —(C 3 -C 7 )cycloalkyl; [0039] where the alkyl and cycloalkyl groups in the definition of R 1 are optionally substituted with (C 1 -C 4 )alkyl, hydroxy, (C 1 -C 4 )alkoxy, carboxyl, —CONH 2 , —S(O) m (C 1 -C 6 )alkyl, —CO 2 (C 1 -C 4 )alkyl ester, 1 H-tetrazol-5-yl or 1, 2 or 3 fluoro groups; [0040] Y 1 is O, S(O) m , —C(O)NX 6 —, —CH═CH—, —C≡C—, —N(X 6 )C(O)—, —C(O)NX 6 —, —C(O)O—, —OC(O)N(X 6 )— or —OC(O)—; [0041] q is 0, 1, 2, 3 or 4; [0042] t is 0, 1, 2 or 3; [0043] said (CH 2 ) q group and (CH 2 ) t group in the definition of R 1 are optionally independently substituted with hydroxy, (C 1 -C 4 )alkoxy, carboxyl, —CONH 2 , —S(O) m (C 1 -C 6 )alkyl, —CO 2 (C 1 -C 4 )alkyl ester, 1H-tetrazol-5-yl, 1, 2 or 3 fluoro groups or 1 or 2 (C 1 -C 4 )alkyl groups; [0044] R 1A is selected from the group consisting of hydrogen, F, Cl, Br, I, (C 1 -C 6 )alkyl, phenyl(C 1 -C 3 )alkyl, pyridyl(C 1 -C 3 )alkyl, thiazolyl(C 1 -C 3 )alkyl and thienyl(C 1 -C 3 )alkyl, provided that R 1A is not F, Cl, Br or I when a heteroatom is vicinal to C″; [0045] R 2 is hydrogen, (C 1 -C 8 )alkyl, —(C 0 -C 3 )alkyl—(C 3 -C 8 )cycloalkyl, —(C 1 -C 4 )alkyl-A 1 or A −1 ; [0046] where the alkyl groups and the cycloalkyl groups in the definition of R 2 are optionally substituted with hydroxy, —C(O)OX 6 , —C(O)N(X 6 )(X 6 ), —N(X 6 )(X 6 ), —S(O) m (C 1 -C 6 )alkyl, —C(O)A 1 , —C(O)(X 6 ), CF 3 , CN or 1, 2 or 3 independently selected halo groups; [0047] R 3 is selected from the group consisting of A 1 , (C 1 -C 10 )alkyl, —(C 1 -C 6 )alkyl-A 1 , —(C 1 -C 6 )alkyl-(C 3 -C 7 )cycloalkyl, —(C 1 -C 5 )alkyl-X 1 -(C 1 -C 5 )alkyl, —(C 1 -C 5 )alkyl-X 1 -(C 0 -C 5 )alkyl-A 1 and —(C 1 -C 5 )alkyl-X 1 —(C 1 -C 5 )alkyl-(C 3 -C 7 )cycloalkyl; [0048] where the alkyl groups in the definition of R 3 are optionally substituted with —S(O) m (C 1 -C 6 )alkyl, —C(O)OX 3 , 1, 2, 3, 4 or 5 independently selected halo groups or 1, 2 or 3 independently selected —OX 3 groups; [0049] X 1 is O, S(O) m , —N(X 2 )C(O)—, —C(O)N(X 2 )—, —OC(O)—, —C(O)O—, —CX 2 ═CX 2 —, —N(X 2 )C(O)O—, —OC(O)N(X 2 )— or —C≡C—; [0050] R 4 is hydrogen, (C 1 -C 6 )alkyl or (C 3 -C 7 )cycloalkyl, or R 4 is taken together with R 3 and the carbon atom to which they are attached and form (C 5 -C 7 )cycloalkyl, (C 5 -C 7 )cycloalkenyl, a partially saturated or fully saturated 4- to 8-membered ring having 1 to 4 heteroatoms independently selected from the group consisting of oxygen, sulfur and nitrogen, or is a bicyclic ring system consisting of a partially saturated or fully saturated 5- or 6-membered ring, fused to a partially saturated, fully unsaturated or fully saturated 5- or 6-membered ring, optionally having 1 to 4 heteroatoms independently selected from the group consisting of nitrogen, sulfur and oxygen; [0051] X 4 is hydrogen or (C 1 -C 6 )alkyl or X 4 is taken together with R 4 and the nitrogen atom to which X 4 is attached and the carbon atom to which R 4 is attached and form a five to seven membered ring; [0052] R 6 is a bond or is [0053] X 5 and X 5a are each independently selected from the group consisting of hydrogen, CF 3 , A 1 and optionally substituted (C 1 -C 6 )alkyl; [0054] the optionally substituted (C 1 -C 6 )alkyl in the definition of X 5 and X 5a is optionally substituted with a substituent selected from the group consisting of A 1 , OX 2 , —S(O) m (C 1 -C 6 )alkyl, —C(O)OX 2 , (C 3 -C 7 )cycloalkyl, —N(X 2 )(X 2 ) and —C(O)N(X 2 )(X 2 ); [0055] or the carbon bearing X 5 or X 5a forms one or two alkylene bridges with the nitrogen atom bearing R 7 and R 8 wherein each alkylene bridge contains 1 to 5 carbon atoms, provided that when one alkylene bridge is formed then only one of X 5 or X 5a is on the carbon atom and only one of R 7 or R 8 is on the nitrogen atom and further provided that when two alkylene bridges are formed then X 5 and X 5a cannot be on the carbon atom and R 7 and R 8 cannot be on the nitrogen atom; [0056] or X 5 is taken together with X 5a and the carbon atom to which they are attached and form a partially saturated or fully saturated 3- to 7-membered ring, or a partially saturated or fully saturated 4- to 8-membered ring having 1 to 4 heteroatoms independently selected from the group consisting of oxygen, sulfur and nitrogen; [0057] or X 5 is taken together with X 5a and the carbon atom to which they are attached and form a bicyclic ring system consisting of a partially saturated or fully saturated 5- or 6-membered ring, optionally having 1 or 2 heteroatoms independently selected from the group consisting of nitrogen, sulfur and oxygen, fused to a partially saturated, fully saturated or fully unsaturated 5- or 6-membered ring, optionally having 1 to 4 heteroatoms independently selected from the group consisting of nitrogen, sulfur and oxygen; [0058] Z 1 is a bond, O or N—X 2, provided that when a and b are both 0 then Z 1 is not N—X 2 or O; or [0059] R 6 is —(CR a R b ) a -E-(CR a R b )b, where the —(CR a R b ) a — group is attached to the carbonyl carbon of the amide group of the compound of formula I and the —(CR a R b ) b group is attached to the terminal nitrogen atom of the compound of formula I; [0060] E is —O—, —S—, —CH═CH— or an aromatic moiety selected from [0061]  said aromatic moiety in the definition of E optionally substituted with up to three halo, hydroxy, —N(R c )(R c ), (C 1 -C 6 )alkyl or (C 1 -C 6 )alkoxy; [0062] R a and R b are, for each occurrence, independently hydrogen, (C 1 -C 6 )alkyl, trifluoromethyl, phenyl or monosubstituted (C 1 -C 6 )alkyl where the substituents are imidazolyl, naphthyl, phenyl, indolyl, p-hydroxyphenyl, —OR c , S(O) m R c , C(O)OR c , (C 3 -C 7 )cycloalkyl, —N(R c )(R c ), —C(O)N(R c )(R c ), or R a or R b may independently be joined to one or both of R 7 or E (where E is other than O, S or —CH═CH—) to form an alkylene bridge between the terminal nitrogen and the alkyl portion of the R a or R b and the R 7 or E group, wherein the bridge contains 1 to 8 carbon atoms; or R a and R b may be joined to one another to form a (C 3 -C 7 )cycloalkyl; [0063] R c , for each occurrence, is independently hydrogen or (C 1 -C 6 )alkyl; [0064] a and b are independently 0, 1, 2 or 3, with the proviso that if E is —O— or —S—, b is other than 0 or 1 and with the further proviso that if E is —CH═CH—, b is other than 0; [0065] R 7 and R 8 are each independently hydrogen or optionally substituted (C 1 -C 6 )alkyl; [0066] where the optionally substituted (C 1 -C 6 )alkyl in the definition of R 7 and R 8 is optionally independently substituted with A 1 , —C(O)O—(C 1 -C 6 )alkyl, —S(O) m (C 1 -C 6 )alkyl, 1 to 5 halo groups, 1 to 3 hydroxy groups, 1 to 3 —O—C(O)(C 1 -C 10 )alkyl groups or 1 to 3 (C 1 -C 6 )alkoxy groups; or [0067] R 7 and R 8 can be taken together to form —(CH 2 ) r -L-(CH 2 ) r —; [0068] where L is C(X 2 )(X 2 ), S(O) m or N(X 2 ); [0069] R 9 and R 10 are each independently selected from the group consisting of hydrogen, fluoro, hydroxy and (C 1 -C 5 )alkyl optionally independently substituted with 1-5 halo groups; [0070] R 11 is selected from the group consisting of (C 1 -C 5 )alkyl and phenyl optionally substituted with 1-3 substitutents each independently selected from the group consisting of (C 1 -C 5 )alkyl, halo and (C 1 -C 5 )alkoxy; [0071] R 12 is selected from the group consisting of (C 1 -C 5 )alkylsulfonyl, (C 1 -C 5 )alkanoyl and (C 1 -C 5 )alkyl where the alkyl portion is optionally independently substituted by 1-5 halo groups; [0072] A 1 for each occurrence is independently selected from the group consisting of (C 5 -C 7 )cycloalkenyl, phenyl, a partially saturated, fully saturated or fully unsaturated 4- to 8-membered ring optionally having 1 to 4 heteroatoms independently selected from the group consisting of oxygen, sulfur and nitrogen and a bicyclic ring system consisting of a partially saturated, fully unsaturated or fully saturated 5- or 6-membered ring, optionally having 1 to 4 heteroatoms independently selected from the group consisting of nitrogen, sulfur and oxygen, fused to a partially saturated, fully saturated or fully unsaturated 5- or 6-membered ring, optionally having 1 to 4 heteroatoms independently selected from the group consisting of nitrogen, sulfur and oxygen; [0073] A 1 for each occurrence is independently optionally substituted, on one or optionally both rings if A 1 is a bicyclic ring system, with up to three substituents, each substituent independently selected from the group consisting of F, Cl, Br, I, OCF 3 , OCF 2 H, CF 3 , CH 3 , OCH 3 , —OX 6 , —C(O)N(X 6 )(X 6 ), —C(O)OX 6 , oxo, (C 1 -C 6 )alkyl, nitro, cyano, benzyl, —S(O) m (C 1 -C 6 )alkyl, 1H-tetrazol-5-yl, phenyl, phenoxy, phenylalkyloxy, halophenyl, methylenedioxy, —N(X 6 )(X 6 ), —N(X 6 )C(O)(X 6 ), —S(O) 2 N (X 6 )(X 6 ), —N(X 6 )S(O) 2 -phenyl, —N(X 6 )S(O) 2 X 6 , —CONX 11 X 12 , —S(O) 2 NX 11 X 12 , —NX 6 S(O) 2 X 12 , —NX 6 CONX 11 X 12 , —NX 6 S(O) 2 NX 11 X 12 , —NX 6 C(O)X 12 , imidazolyl, thiazolyl and tetrazolyl, provided that if A 1 is optionally substituted with methylenedioxy then it can only be substituted with one methylenedioxy; [0074] where X 11 is hydrogen or optionally substituted (C 1 -C 6 )alkyl; [0075] the optionally substituted (C 1 -C 6 )alkyl defined for X 11 is optionally independently substituted with phenyl, phenoxy, (C 1 -C 6 )alkoxycarbonyl, —S(O) m (C 1 -C 6 )alkyl, 1 to 5 halo groups, 1 to 3 hydroxy groups, 1 to 3 (C 1 -C 1 0 )alkanoyloxy groups or 1 to 3 (C 1 -C 6 )alkoxy groups; [0076] X 12 is hydrogen, (C 1 -C 6 )alkyl, phenyl, thiazolyl, imidazolyl, furyl or thienyl, provided that when X 12 is not hydrogen, the X 12 group is optionally substituted with one to three substituents independently selected from the group consisting of Cl, F, CH 3 , OCH 3 , OCF 3 and CF 3 ; [0077] or X 11 and X 12 are taken together to form —(CH 2 ) r -L 1 -(CH 2 ) r —; [0078] L 1 is C(X 2 )(X 2 ), O, S(O) m or N(X 2 ); [0079] r for each occurrence is independently 1, 2 or 3; [0080] X 2 for each occurrence is independently hydrogen, optionally substituted (C 1 -C 6 )alkyl or optionally substituted (C 3 -C 7 )cycloalkyl, where the optionally substituted (C 1 -C 6 )alkyl and optionally substituted (C 3 -C 7 )cycloalkyl in the definition of X 2 are optionally independently substituted with —S(O) m (C 1 -C 6 )alkyl, —C(O)OX 3 , 1 to 5 halo groups or 1-3 OX 3 groups; [0081] X 3 for each occurrence is independently hydrogen or (C 1 -C 6 )alkyl; [0082] X 6 for each occurrence is independently hydrogen, optionally substituted (C 1 -C 6 )alkyl, (C 2 -C 6 )halogenated alkyl, optionally substituted (C 3 -C 7 )cycloalkyl, (C 3 -C 7 )halogenated cycloalkyl, where optionally substituted (C 1 -C 6 )alkyl and optionally substituted (C 3 -C 7 )cycloalkyl in the definition of X 6 is optionally independently mono- or di-substituted with (C 1 -C 4 )alkyl, hydroxy, (C 1 -C 4 )alkoxy, carboxyl, CONH 2 , —S(O) m (C 1 -C 6 )alkyl, carboxylate (C 1 -C 4 )alkyl ester or 1 H-tetrazol-5-yl; or when there are two X 6 groups on one atom and both X 6 are independently (C 1 -C 6 )alkyl, the two (C 1 -C 6 )alkyl groups may be optionally joined and, together with the atom to which the two X 6 groups are attached, form a 4- to 9-membered ring optionally having oxygen, sulfur or NX 7 as a ring member; [0083] X 7 is hydrogen or (C 1 -C 6 )alkyl optionally substituted with hydroxy; [0084] m for each occurrence is independently 0, 1 or 2; [0085] with the proviso that: [0086] X 6 and X 12 cannot be hydrogen when attached to C(O) or S(O) 2 in the form C(O)X 6 , C(O)X 12 , S(O) 2 X 6 or S(O) 2 X 12 ; and [0087] when R 6 is a bond then L is N(X 2 ) and each r in the definition —(CH 2 ) r -L-(CH 2 ) r — is independently 2 or 3; [0088] a prodrug thereof or a pharmaceutically acceptable salt of said compound or of said prodrug. [0089] In the combinations, pharmaceutical compositions, methods and kits of this invention, it is especially preferred that said GHS is a compound of the formula [0090] or a stereoisomeric mixture thereof, diastereomerically enriched, diastereomerically pure, enantiomerically enriched or enantiomerically pure isomer thereof, [0091] wherein: [0092] wherein [0093] f is 0; [0094] n is 0 and w is 2, or n is 1 and w is 1, or n is 2 and w is 0; [0095] Y is oxygen or sulfur; [0096] R 1 is hydrogen, —CN, —(CH 2 ) q N(X 6 )C(O)X 6 , (CH 2 ) q N(X 6 )C(O)(CH 2 ) t -A 1 , —(CH 2 ) q N(X 6 )SO 2 (CH 2 ) t -A 1 , (CH 2 ) q N(X 6 )S0 2 X 6 , —(CH 2 ) q N(X 6 )C(O)N(X 6 )(CH 2 ) t -A 1 , —(CH 2 ) q N(X 6 )C(O)N(X 6 )(X 6 ), (CH 2 ) q C(O)N(X 6 )(X 6 ), (CH 2 ) q C(O)N(X 6 )(CH 2 ) t -A 1 , (CH 2 ) q C(O)OX 6 —(CH 2 ) q C(O)O(CH 2 ) t -A 1 , (CH 2 ) q OX 6 , —(CH 2 ) q OC(O)X 6 , —(CH 2 ) q OC(O)(CH 2 ) t -A 1 , —(CH 2 ) q OC(O)N(X 6 )(CH 2 ) t -A 1 , —(CH 2 ) q OC(O)N(X 6 )(X 6 ), (CH 2 ) q C(O)X 6 , (CH 2 ) q C(O)(CH 2 ) t -A 1 , (CH 2 ) q N(X 6 )C(O)OX 6 , —(CH 2 ) q N(X 6 )SO 2 N(X 6 )(X 6 ), (CH 2 ) q S(O) m X 6 —(CH 2 ) q S(O) m (CH 2 ) t -A 1 , —(C 1 -C 10 )alkyl, —(CH 2 ) t -A, —(CH 2 ) q —(C 3 -C 7 )cycloalkyl, —(CH 2 ) q —Y—(C 1 -C 6 )alkyl, (CH 2 ) q -Y 1 l—(CH 2 ) t -A 1 or —(CH 2 ) q —Y 1 —(CH 2 ) t —(C 3 -C 7 )cycloalkyl; [0097] where the alkyl and cycloalkyl groups in the definition of R 1 are optionally substituted with (C 1 -C 4 )alkyl, hydroxyl, (C 1 -C 4 )alkoxy, carboxyl, —CONH 2 , —S(O) m (C 1 -C 6 )alkyl, —CO 2 (C 1 -C 4 )alkyl ester, 1H-tetrazol-5-yl or 1, 2 or 3 fluoro; [0098] Y 1 is O, S(O) m , —C(O)NX 6 —, —CH═CH—, —C≡C—, —N(X 6 )C(O)—, —C(O)NX 6 —, —C(O)O—, —OC(O)N(X 6 )— or —OC(O)—; [0099] q is 0, 1, 2, 3 or 4; [0100] t is 0, 1, 2 or 3; [0101] said (CH 2 ) q group and (CH 2 ) t group may each be optionally substituted with hydroxyl, (C 1 -C 4 )alkoxy, carboxyl, —CONH 2 , —S(O) m (C 1 -C 6 )alkyl, —CO 2 (C 1 -C 4 )alkyl ester, 1H-tetrazol-5-yl, 1, 2 or 3 fluoro, or 1 or 2 (C 1 -C 4 )alkyl; [0102] R 2 is hydrogen, (C 1 -C 8 )alkyl, —(C 0 -C 3 )alkyl-(C 3 -C 8 )cycloalkyl, —(C 1 -C 4 )alkyl-A 1 or A 1 ; [0103] where the alkyl groups and the cycloalkyl groups in the definition of R 2 are optionally substituted with hydroxyl, —C(O)OX 6 , —C(O)N(X 6 )(X 6 ), —N(X 6 )(X 6 ), —S(O) m (C 1 -C 6 )alkyl, —C(O)A, —C(O)(X 6 ), CF 3 , CN or 1, 2 or 3 halogen; [0104] R 3 is A 1 , (C 1 -C 10 )alkyl, —(C 1 -C 6 )alkyl-A, —(C 1 -C 6 )alkyl-(C 3 -C 7 )cycloalkyl, —(C 1 -C 5 )alkyl-X—(C 1 -C 5 )alkyl, —(C 1 -C 5 )alkyl-X—(C 0 -C 5 )alkyl-A 1 or —(C 1 -C 5 )alkyl-X—(C 1 -C 5 )alkyl-(C 3 -C 7 )cycloalkyl; [0105] where the alkyl groups in the definition of R 3 are optionally substituted with, —S(O) m (C 1 -C 6 )alkyl, —C(O)OX 3 , 1, 2, 3, 4 or 5 halogens, or 1, 2 or 3 OX 3 ; [0106] X 1 is O, S(O) m , —N(X 2 )C(O)—, —C(O)N(X 2 )—, —OC(O)—, —C(O)O—, —CX 2 ═CX 2 —, —N(X 2 )C(O)O—, —OC(O)N(X 2 )— or —C≡C—; [0107] R 4 is hydrogen, (C 1 -C 6 )alkyl or (C 3 -C 7 )cycloalkyl; [0108] X 4 is hydrogen or (C 1 -C 6 )alkyl or X 4 is taken together with R 4 and the nitrogen atom to which X 4 is attached and the carbon atom to which R 4 is attached and form a five to seven membered ring; [0109] R 6 is a bond or is [0110] where a and b are independently 0, 1, 2 or 3; [0111] X 5 and X 5a are each independently selected from the group consisting of hydrogen, trifluoromethyl, A 1 and optionally substituted (C 1 -C 6 )alkyl; [0112] the optionally substituted (C 1 -C 6 )alkyl in the definition of X 5 and X 5a is optionally substituted with a substituent selected from the group consisting of A 1 , OX 2 , —S(O) m (C 1 -C 6 )alkyl, —C(O)OX 2 , (C 3 -C 7 )cycloalkyl, —N(X 2 )(X 2 ) and —C(O)N(X 2 )(X 2 ); [0113] R 7 and R 8 are independently hydrogen or optionally substituted (C 1 -C 6 )alkyl; [0114] where the optionally substituted (C 1 -C 6 )alkyl in the definition of R 7 and R 8 is optionally independently substituted with A 1 , —C(O)O—(C 1 -C 6 )alkyl, —S(O) m (C 1 -C 6 )alkyl, 1 to 5 halogens, 1 to 3 hydroxy, 1 to 3 —O—C(O)(C 1 -C 10 )alkyl or 1 to 3 (C 1 -C 6 )alkoxy; or [0115] R 7 and R 8 can be taken together to form —(CH 2 ) r -L-(CH 2 ) r —; [0116] where L is C(X 2 )(X 2 ), S(O) m or N(X 2 ); [0117] A 1 in the definition of R 1 is a partially saturated, fully saturated or fully unsaturated 4- to 8-membered ring optionally having 1 to 4 heteroatoms independently selected from the group consisting of oxygen, sulfur and nitrogen, a bicyclic ring system consisting of a partially saturated, fully unsaturated or fully saturated 5- or 6-membered ring, having 1 to 4 heteroatoms independently selected from the group consisting of nitrogen, sulfur and oxygen, fused to a partially saturated, fully saturated or fully unsaturated 5- or 6-membered ring, optionally having I to 4 heteroatoms independently selected from the group consisting of nitrogen, sulfur and oxygen; [0118] A 1 in the definition of R 2 , R 3 , R 6 , R 7 and R 8 is independently (C 5 -C 7 )cycloalkenyl, phenyl or a partially saturated, fully saturated or fully unsaturated 4- to 8-membered ring optionally having 1 to 4 heteroatoms independently selected from the group consisting of oxygen, sulfur and nitrogen, a bicyclic ring system consisting of a partially saturated, fully unsaturated or fully saturated 5- or 6-membered ring, optionally having 1 to 4 heteroatoms independently selected from the group consisting of nitorgen, sulfur and oxygen, fused to a partially saturated, fully saturated or fully unsaturated 5- or 6-membered ring, optionally having 1 to 4 heteroatoms independently selected from the group consisting of nitrogen, sulfur and oxygen; [0119] A 1 for each occurrence is independently optionally substituted, in one or optionally both rings if A 1 is a bicyclic ring system, with up to three substituents, each substituent independently selected from the group consisting of F, Cl, Br, I, OCF 3 , OCF 2 H, CF 3 , CH 3 , OCH 3 , -OX 6 , —C(O)N(X 6 )(X 6 ), —C(O)OX 6 , oxo, (C 1 -C 6 )alkyl, nitro, cyano, benzyl, —S(O) m (C 1 -C 6 )alkyl, 1H-tetrazol-5-yl, phenyl, phenoxy, phenylalkyloxy, halophenyl, methylenedioxy, —N(X 6 )(X 6 ), —N (X 6 )C(O)(X 6 ), —SO 2 N(X 6 )(X 6 ), —N(X 6 )SO 2 -phenyl, —N(X 6 )SO 2 X 6 , —CONX IX 12, —SO 2 NX 1 IX 12 , —NX 6 S0 2 X 12 , —NX 6 CONX 11 X 12 , —NX 6 SO 2 NX 11 X 12 , —NX 6 C(O)X 12 , imidazolyl, thiazolyl or tetrazolyl, provided that if A 1 is optionally substituted with methylenedioxy then it can only be substituted with one methylenedioxy; [0120] where X 11 is hydrogen or optionally substituted (C 1 -C 6 )alkyl; [0121] the optionally substituted (C 1 -C 6 )alkyl defined for X 11 is optionally independently substituted with phenyl, phenoxy, (C 1 -C 6 )alkoxycarbonyl, —S(O) m (C 1 -C 6 )alkyl 1 to 5 halogens, 1 to 3 hydroxy, 1 to 3 (C 1 -C 10 )alkanoyloxy or 1 to 3 (C 1 -C 6 )alkoxy; [0122] X 12 is hydrogen, (C 1 -C 6 )alkyl, phenyl, thiazolyl, imidazolyl, furyl or thienyl, provided that when X 12 is not hydrogen, X 12 is optionally substituted with one to three substituents independently selected from the group consisting of Cl, F, CH 3 , OCH 3 , OCF 3 and CF 3 ; [0123] or X 11 and X 12 are taken together to form —(CH 2 ) r -L-(CH 2 ) r —; [0124] where L 1 is C(X 2 )(X 2 ), O, S(O) m or N(X 2 ); [0125] r for each occurrence is independently 1, 2 or 3; [0126] X 2 for each occurrence is independently hydrogen, optionally substituted (C 1 -C 6 )alkyl, or optionally substituted (C 3 -C 7 )cycloalkyl, where the optionally substituted (C 1 -C 6 )alkyl and optionally substituted (C 3 -C 7 )cycloalkyl in the definition of X 2 are optionally independently substituted with —S(O) m (C 1 -C 6 )alkyl, —C(O)OX 3 , 1 to 5 halogens or 1-3 OX 3 ; [0127] X 3 for each occurrence is independently hydrogen or (C 1 -C 6 )alkyl; [0128] X 6 is independently hydrogen, optionally substituted (C 1 -C 6 )alkyl, (C 2 -C 6 )halogenated alkyl, optionally substituted (C 3 -C 7 )cycloalkyl, (C 3 -C 7 )-halogenatedcycloalkyl, where optionally substituted (C 1 -C 6 )alkyl and optionally substituted (C 3 -C 7 )cycloalkyl in the definition of X 6 is optionally independently substituted by 1 or 2 (C 1 -C 4 )alkyl, hydroxyl, (C 1 -C 4 )alkoxy, carboxyl, CONH 2 , —S(O) m (C 1 -C 6 )alkyl, carboxylate (C 1 -C 4 )alkyl ester, or 1H-tetrazol-5-yl; or when there are two X 6 groups on one atom and both X 6 are independently (C 1 -C 6 )alkyl, the two (C 1 -C 6 )alkyl groups may be optionally joined and, together with the atom to which the two X 6 groups are attached, form a 4- to 9-membered ring optionally having oxygen, sulfur or NX 7 ; [0129] X 7 is hydrogen or (C 1 -C 6 )alkyl optionally substituted with hydroxyl; and [0130] m for each occurrence is independently 0, 1 or 2; [0131] with the proviso that: [0132] X 6 and X 12 cannot be hydrogen when it is attached to C(O) or SO 2 in the form C(O)X 6 , C(O)X 12 , SO 2 X 6 or SO 2 X 12 ; and [0133] when R 6 is a bond then L is N(X 2 ) and each r in the definition —(CH 2 ) r -L-(CH 2 ) r — is independently 2 or 3. [0134] In the combinations, pharmaceutical compositions, methods and kits of this invention, it is even more especially preferred that said GHS is 2-amino-N-(1 (R)-benzyloxymethyl-2-(1,3-dioxo-8a(S)-pyridin-2-ylmethyl-2-(2,2,2-trifluoro-ethyl)-hexahydro-imidazo[1,5-a]pyrazin-7-yl]-2-oxo-ethyl)-2-methyl-propionamide; 2-amino-N-[2-(3a-(R)-benzyl-2-methyl-3-oxo-2,3,3a,4,6,7-hexahydro-pyrazolo-[4,3-c]pyridin-5-yl)-1-(R)-benzyloxymethyl-2-oxo-ethyl]-isobutyramide; or 2-amino-N-(1-(R)-(2,4-difluoro-benzyloxymethyl)-2-oxo-2-(3-oxo-3a-(R)-pyridin-2-ylmethyl)-2-(2,2,2-trifluoroethyl)-2,3,3a,4,6,7-hexahydro-pyrazolo[4,3-c]pyridin-5-yl)-ethyl)-2-methylpropionamide, a prodrug thereof or a pharmaceutically acceptable salt thereof or of said prodrug. [0135] In the combinations, pharmaceutical compositions, methods and kits of this invention, it is still more especially preferred that the L-tartrate salt of 2-amino-N-(1 (R)-benzyloxymethyl-2-(1,3-dioxo-8a(S)-pyridin-2-ylmethyl-2-(2,2,2-trifluoro-ethyl)-hexahydro-imidazo[1,5-a]pyrazin-7-yl]-2-oxo-ethyl)-2-methyl-propionamide; the L-tartrate salt of 2-amino-N-(2-(3a(R)-benzyl-2-methyl-3-oxo-2,3, 3a, 4,6,7-hexahydro-pyrazolo-[4,3-c]pyridin-5-yl)-1 (R)-benzyloxymethyl-2-oxo-ethyl)-isobutyramide; or the L-tartrate salt of 2-amino-N-(1-(R)-(2,4-difluoro-benzyloxymethyl)-2-oxo-2-(3-oxo-3a-(R)-pyridin-2-yl)-2-(2,2,2-trifluoro-ethyl)-2,3,3a,4,6,7-hexahydro-pyrazolo-[4,3-c]pyridin-5-yl)-ethyl)-2-methyl-propionamide is used. [0136] In the combinations, pharmaceutical compositions, methods and kits of this invention, it is also preferred that said GHS is hexarelin, ipamorelin, MK-0677, NN703, L-162752, L-163022, GPA-748, KP102, GHRP-2 or LY444711. [0137] This invention is also directed to a method of improving the physical or psychological condition of a patient undergoing a medical procedure comprising administering to said patient: [0138] a) a pharmaceutical composition comprising a GHS, a prodrug thereof or a pharmaceutically acceptable salt of said GHS or of said prodrug, an antidepressant, a prodrug thereof or a pharmaceutically acceptable salt of said antidepressant or of said prodrug, and a pharmaceutically acceptable vehicle, carrier or diluent; or [0139] b) a GHS, prodrug thereof, pharmaceutically acceptable salt of said GHS or of said prodrug or a pharmaceutical composition thereof and an antidepressant, prodrug thereof, pharmaceutically acceptable salt of said antidepressant or said prodrug or a pharmaceutical composition thereof. This invention thus includes methods whereby a fixed combination is administered and methods whereby the individual components of the combination are administered separately. This invention is particularly directed to such methods wherein the cardiac function, metabolism, muscle tone or mental state of said patient is improved. [0140] It is preferred that said medical procedure is a surgical or dental procedure, though patients undergoing other medical procedures which adversely affect the mental state of said patient may also be treated by the methods of this invention. The combination may be administered before, during or after said surgical or dental procedure. [0141] This invention is also directed to a method for treating musculoskeletal frailty in a mammal comprising administering to said mammal: [0142] a) a pharmaceutical composition comprising a GHS, a prodrug thereof or a pharmaceutically acceptable salt of said GHS or of said prodrug, an antidepresant, a prodrug thereof or a pharmaceutically acceptable salt of said antidepressant or of said prodrug, and a pharmaceutically acceptable vehicle, carrier or diluent; or [0143] b) a GHS, prodrug thereof, pharmaceutically acceptable salt of said GHS or of said prodrug or a pharmaceutical composition thereof and an antidepressant, prodrug thereof, pharmaceutically acceptable salt of said antidepressant or said prodrug or a pharmaceutical composition thereof. This invention thus includes methods whereby a fixed combination is administered and methods whereby the individual components of the combination are administered separately. This invention is particularly directed to such methods wherein bone healing following facial reconstruction, maxillary reconstruction or mandibular reconstruction is treated, vertebral synostosis is induced or long bone extension is enhanced, the healing rate of a bone graft is enhanced or prosthetic ingrowth is enhanced. This invention is also particularly directed to such methods wherein muscle mass is increased. [0144] This invention is also directed to a kit comprising: [0145] a) a first unit dosage form comprising a GHS, a prodrug thereof or a pharmaceutically acceptable salt of said GHS or said prodrug and a pharmaceutically acceptable carrier, vehicle or diluent; [0146] b) a second unit dosage form comprising an antidepressant, a prodrug thereof or a pharmaceutically acceptable salt of said antidepressant or said prodrug and a pharmaceutically acceptable carrier, vehicle or diluent; and [0147] c) a container. [0148] This invention is also directed to a method of treating congestive heart failure in a mammal comprising administering to said mammal: [0149] a) a pharmaceutical composition comprising a GHS, a prodrug thereof or a pharmaceutically acceptable salt of said GHS or of said prodrug, an antidepressant, a prodrug thereof or a pharmaceutically acceptable salt of said antidepressant or of said prodrug, and a pharmaceutically acceptable vehicle, carrier or diluent; or [0150] b) a GHS, prodrug thereof, pharmaceutically acceptable salt of said GHS or of said prodrug or a pharmaceutical composition thereof and an antidepressant, prodrug thereof, pharmaceutically acceptable salt of said antidepressant or said prodrug or a pharmaceutical composition thereof. This invention thus includes methods whereby a fixed combination is administered and methods whereby the individual components of the combination are administered separately. [0151] This invention is also directed to a method of attenuating protein catabolic response after a major operation in a mammal comprising adminstering to said mammal: [0152] a) a pharmaceutical composition comprising a GHS, a prodrug thereof or a pharmaceutically acceptable salt of said GHS or of said prodrug, an antidepressant, a prodrug thereof or a pharmaceutically acceptable salt of said antidepressant or of said prodrug, and a pharmaceutically acceptable vehicle, carrier or diluent; or [0153] b) a GHS, prodrug thereof, pharmaceutically acceptable salt of said GHS or of said prodrug or a pharmaceutical composition thereof and an antidepressant, prodrug thereof, pharmaceutically acceptable salt of said antidepressant or said prodrug or a pharmaceutical composition thereof. This invention thus includes methods whereby a fixed combination is administered and methods whereby the individual components of the combination are administered separately. [0154] The phrase “condition which presents with low bone mass” refers to a condition where the level of bone mass is below the age specific normal as defined in standards by the World Health Organization “Assessment of Fracture Risk and its Application to Screening for Postmenopausal Osteoporosis (1994), Report of a World Health Organization Study Group. World Health Organization Technical Series 843′. Childhood idiopathic and primary osteoporosis are also included. Included in the treatment of osteoporosis is the prevention or attenuation of long term complications such as curvature of the spine, loss of height, prosthetic surgery, and prevention of prostate malfunctioning. Also included is increasing the bone fracture healing rate and enhancing the rate of successful bone grafts. Also included is periodontal disease and alveolar bone loss. [0155] The prospect of surgery, whether invasive or non-invasive, often leads to depressed mental states in patients. Such mental states can be detrimental to rapid recovery from the surgical procedure. Patients with depressed mental states or at risk of acquiring a depressed mental state can be treated with the combination of this invention. [0156] The phrase “musculoskeletal frailty” refers to a condition wherein a subject has low bone mass and/or low muscle mass, and includes such diseases, disorders and conditions as, but not limited to, conditions which present with low bone mass, osteoporosis, conditions which present with low muscle mass, osteotomy, childhood idiopathic bone loss, bone loss associated with periodontitis, bone healing following facial reconstruction, maxillary reconstruction, mandibular reconstruction and bone fracture. Further, musculoskeletal frailty encompasses such conditions as interfaces between newly attached prostheses and bone which require bone ingrowth. [0157] The term “pharmaceutically acceptable” means that a substance or mixture of substances must be compatible with the other ingredients of a formulation and not deleterious to a patient. [0158] The term “treating”, “treat” or “treatment” as used herein includes curative, preventative (e.g., prophylactic) and palliative treatment. [0159] The terms “patient” and “subject” are used interchangeably and refer to animals, particularly mammals such as dogs, cats, cattle, horses, sheep and humans. Particularly preferred patients and subjects are humans, including males and females. [0160] The parenthetical negative or positive sign used herein in the nomenclature denotes the direction plane polarized light is rotated by the particular stereoisomer. [0161] The subject invention also includes combinations, pharmaceutical compositions, methods and kits comprising isotopically-labeled compounds, which are identical to the compounds described hereinabove, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds used in the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, sulfur, fluorine and chlorine, such as 2 H, 3 H, 13 C, 14 C, 15 N, 18 O, 17 O, 31 P, 32 P, 35 S, 18 F and 36 Cl, respectively. Compounds used in the present invention, prodrugs thereof, and pharmaceutically acceptable salts of said compounds or of said prodrugs which contain the aforementioned isotopes and/or other isotopes of other atoms are within the scope of this invention. Certain isotopically-labeled compounds of the present invention, for example those into which racioactive isotopes such as 3 H and 14 C are incorporated, are useful in drug and/or substrate tissue distribution assays. Tritiated, i.e., 3 H, and carbon-14, i.e., 14 C, isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium, i.e., 2 H, can afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements and, hence, may be preferred in some circumstances. Isotopically labeled compounds used in this invention and prodrugs thereof can generally be prepared by carrying out the procedures disclosed in the Schemes and /or in the Examples and Preparations described in the patents and applications which are incorporated herein by reference, by substituting a readily available isotopically labeled reagent for a non-isotopically labeled reagent. [0162] The combinations, pharmaceutical compositions, kits and methods of this invention increase bone density and muscle mass while at the same time reducing fat mass and total serum cholesterol. Further, the combinations, pharmaceutical compositions, kits and methods of this invention result in improved cardiac output, improved wound healing, higher metabolism and improved mental state which provides for positive outcomes following medical procedures, including surgical and dental procedures. This invention also makes a significant contribution to the art by providing compositions and methods that increase and maintain bone mass resulting in prevention, retardation, and/or regression of osteoporosis and related bone disorders. [0163] Other features and advantages will be apparent from the description and claims which describe the invention. DETAILED DESCRIPTION OF THE INVENTION [0164] The first compound of this invention is a growth hormone secretagogue (GHS). Any GHS may be used in the combinations, pharmaceutical compositions, methods and kits of this invention. [0165] A representative first class of growth hormone secretagogues within those compounds of Formula I as described hereinabove is set forth in PCT Application Publication No. WO97/24369, which is incorporated herein by reference, as compounds having the structural formula: [0166] wherein the various substituents are as defined in WO97/24369. Said compounds are prepared as disclosed therein. [0167] 2-Amino—N-(2-(3a-(R)-benzyl-2-methyl-3-oxo-2,3,3a ,4,6,7-hexahydro-pyrazolo-[4,3-c]pyridin-5-yl)-1-(R)-benzyloxymethyl-2-oxo-ethyl)-isobutyramide, having the following structure: [0168] and 2-amino-N-(1-(R)-(2,4-difluoro-benzyloxymethyl)-2-oxo-2-(3-oxo-3a-(R)-pyridin-2-ylmethyl)-2-(2,2,2-trifluoro-ethyl)-2,3,3a,4,6,7-hexahydro-pyrazolo-[4,3-c]pyridin-5-yl)-ethyl)-2-methyl-propionamide, having the following structure: [0169] are both within the scope of the disclosure of International Pat. Application Publication No. WO97/24369. [0170] Those compounds of Formula I which are not within the disclosure of International Pat. Application Publication No. WO97/24369 may be prepared as disclosed in International Pat. Application Publication No. WO98/58947, which is incorporated herein by reference. [0171] 2-amino-N-(1 (R)-benzyloxymethyl-2-(1 ,3-dioxo-8a(S)-pyridin-2-ylmethyl-2-(2,2,2-trifluoro-ethyl)-hexahydro-imidazo[1,5-a]pyrazin-7-yl]-2-oxo-ethyl)-2-methyl-propionamide, having the following structure: [0172] is within the scope of the disclosure of International Pat. Application Publication No. WO98/58947. [0173] Other GHS compounds which may be used in the compositions, methods and kits of this invention include the following: [0174] (1) compounds of the formula [0175] wherein the various substituents are defined, and the compounds are prepared, as disclosed in U.S. Pat. No. 5,206,235, which is incorporated herein by reference; [0176] (2) compounds of the formula [0177] wherein the various substituents are defined, and the compounds are prepared, as disclosed in U.S. Pat. No. 5,283,241, which is incorporated herein by reference; [0178] (3) compounds of the formula [0179] wherein the various substituents are defined, and the compounds are prepared, as disclosed in International Pat. Application Publication No. WO97/41879, which is incorporated herein by reference; and [0180] (4) compounds of the formula [0181] wherein the various substituents are defined, and the compounds are prepared, as disclosed in U.S. Pat. No. 5,492,916, which is incorporated herein by reference. [0182] The most preferred compounds within (1) above have the following structures: [0183] The most preferred compound within (3) above has the following structure: [0184] The methanesulfonate salt of this compound is particularly preferred. [0185] Still other compounds which may be used within the compositions, methods and kits of this invention include: [0186] (5) GHRP-6, which is the prototype GH-releasing peptide H-His-D-Trp-Ala-Trp-D-Phe-Lys-NH 2 , (also called His 1 , Lys 6 )-GHRP), is sold commercially by Bachem, catalog number H-9990 and Peninsula Labs, catalog number 8071 and is disclosed in U.S. Pat. No. 4,411,890, which is incorporated herein by reference, and in Bowers et al., Endocrinology, 114:1537, 1984; [0187] (6) GHRP-1, also known as KP101, which is the second generation GH-releasing peptide Ala-His-D-βNaI-Ala-Trp-D-Phe-Lys-NH 2 and is disclosed in Akman, Endocrinology, 132:1286, 1993; [0188] (7) GHRP-2, also known as KP-102 (Kaken) and GPA-748 (Wyeth-Ayerst), which is the GH-releasing peptide D-Ala-D-βNaI-Ala-Trp-D-Phe-Lys-NH 2 and is disclosed in Bowers et al., Endocrinology, 114:1537, 1984 and in Bowers in: Molecular and Clinical Advances in Pituitary Disorders, pp. 153-157, 1993, edited by S. Melmed, Endocrine Research and Education, Inc., Los Angeles, Calif., USA; and [0189] (8) hexarelin, which is His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH 2 , is sold commercially by Peninsula Labs, catalog number 8083, was synthesized by Europeptides, Argenteuil, France and is disclosed in Guillaume et al., Endocrinology, 135, 1073, 1994. [0190] Any antidepressant may be used in the combinations, pharmaceutical compositions, methods and kits of this invention. The term antidepressant means an agent used to treat affective or mood disorders and related conditions. Affective mood disorders are characterized by changes in mood as the primary clinical manifestation. Either extreme of mood may be associated with psychosis, manifested as disordered or delusional thinking and perceptions which are often incongruent with the predominant mood. Affective disorders include major depression and mania, including bipolar manic-depressive illness. Preferred classes of antidepressants include norepinephrine reuptake inhibitors (NERIs), including secondary and tertiary amine tricyclics; selective sertraline reuptake inhibitors; combined NERI/SSRIs; monoamine oxidase (MAO) inhibitors; and atypical antidepressants. [0191] Any norepinephrine reuptake inhibitor (NERI) may be used in the combinations, pharmaceutical compositions, methods and kits of this invention. The term norepinephrine reuptake inhibitor means agents which potentiate the actions of biogenic amines by blocking their major means of physiological inactivation, which involves transport or reuptake into nerve terminals, and specifically, agents which block the reuptake of norepinephrine into said nerve terminals. [0192] Preferred tertiary amine tricyclic norepinephrine reuptake inhibitors which may be used in accordance with this invention include, but are not limited to, amitriptyline, which may be prepared as described in U.S. Pat. No. 3,205,264; chlomipramine, which may be prepared as described in U.S. Pat. No. 3,467,650; doxepin, which may be prepared as described in U.S. Pat. No. 3,420,851; imipramine, which may be prepared as described in U.S. Pat. No. 2,554,736; and trimipramine, which may be prepared as described in Jacob and Messer, Compt. Rend. 252, 2117 (1961). [0193] Preferred secondary amine tricyclic norepinephrine reuptake inhibitors which may be used in accordance with this invention include, but are not limited to, amoxapine, which may be prepared as described in U.S. Pat. No. 3,663,696; desipramine, which may be prepared as described in U.S. Pat. No. 3,454,554; maprotiline, which may be prepared as described in U.S. Pat. No. 3,999,201; nortriptyline, which may be prepared as described in U.S. Pat. No. 3,442,949; and protriptyline, which may be prepared as described in U.S. Pat. No. 3,244,748. [0194] Any selective serotonin reuptake inhibitor (SSRI) may be used in the combinations, pharmaceutical compositions, methods and kits of this invention. The term selective serotonin reuptake inhibitor refers to a compound which inhibits the reuptake of serotonin by afferent neurons. Such inhibition is readily determined by those skilled in the art according to standard assays such as those disclosed in U.S. Pat. No. 4,536,518 and other U.S. patents recited in the next paragraph. [0195] Preferred selective serotonin reuptake inhibitors (SSRI) which may be used in accordance with this invention include, but are not limited to: citalopram, which may be prepared as described in U.S. Pat. No. 4,136,193; femoxetine, which may be prepared as described in U.S. Pat. No. 3,912,743; fluoxetine, which may be prepared as described in U.S. Pat. No. 4,314,081; fluvoxamine, which may be prepared as described in U.S. Pat. No. 4,085,225; indalpine, which may be prepared as described in U.S. Pat. No. 4,064,255; indeloxazine, which may be prepared as described in U.S. Pat. No. 4,109,088; milnacipran, which may be prepared as described in U.S. Pat. No. 4,478,836; paroxetine, which may be prepared as described in U.S. Pat. No. 3,912,743 or U.S. Pat. No. 4,007,196; sertraline and the hydrochloride salt of sertraline, which may be prepared as described in U.S. Pat. No. 4,536,518; sibutramine, which may be prepared as described in U.S. Pat. No. 4,929,629; and zimeldine, which may be prepared as described in U.S. Pat. No. 3,928,369. Fluoxetine is also known as Prozac®. Sertraline hydrochloride is also known as Zoloft®. Sibutramine is also known as Meridia®. [0196] Any combined NERI/SSRI may be used in the combinations, pharmaceutical compositions, methods and kits of this invention. The term combined NERI/SSRI refers to a compound which blocks the reuptake of both serotonin and norepinephrine by afferent neurons. A preferred combined NERI/SSRI which may be used in accordance with this invention is venlafaxine, which may be prepared as described in U.S. Pat. No. 4,535,186. [0197] Any monoamine oxidase (MAO) inhibitor may be used in the combinations, pharmaceutical compositions, methods and kits of this invention. The term monoamine oxidase inhibitor refers to a compound which inhibits monoamine oxidase, for example by blocking the metabolic deamination of a variety of monoamines by mitochondrial monoamine oxidase. Preferred monoamine oxidase inhibitors which may be used in accordance with this invention include, but are not limited to, phenelzine, which may be prepared as described in U.S. Pat. No. 3,000,903; tranylcypromine, which may be prepared as described in U.S. Pat. No. 2,997,422; and selegiline, which may be prepared as described in U.S. Pat. No. 4,564,706. [0198] Any atypical antidepressant may be used in the combinations, pharmaceutical compositions, methods and kits of this invention. The term atypical antidepressant refers to any antidepressant not within any of the aforesaid classes of antidepressants. Preferred atypical antidepressants which may be used in accordance with this invention include, but are not limited to, bupropion, which may be prepared as described in U.S. Pat. No. 3,885,046; nefazodone, which may be prepared as described in U.S. Pat. No. 4,338,317; and trazodone, which may be prepared as described in U.S. Pat. No. 3,381,009. [0199] The disclosures of each of the patents and published patent applications cited within this description are incorporated herein by reference. [0200] The expression “pharmaceutically acceptable salts” includes both pharmaceutically acceptable acid addition salts and pharmaceutically acceptable cationic salts, where appropriate. The expression “pharmaceutically-acceptable cationic salts” is intended to define but is not limited to such salts as the alkali metal salts, (e.g., sodium and potassium), alkaline earth metal salts (e.g., calcium and magnesium), aluminum salts, ammonium salts, and salts with organic amines such as benzathine (N,N′-dibenzylethylenediamine), choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine), benethamine (N-benzylphenethylamine), diethylamine, piperazine, tromethamine (2-amino-2-hydroxymethyl-1,3-propanediol) and procaine. The expression “pharmaceutically-acceptable acid addition salts” is intended to define but is not limited to such salts as the hydrochloride, hydrobromide, sulfate, hydrogen sulfate, phosphate, hydrogen phosphate, dihydrogenphosphate, acetate, succinate, d-tartrate, I-tartrate, citrate, methanesulfonate (mesylate) and p-toluenesulfonate (tosylate) salts. [0201] Pharmaceutically acceptable cationic salts of the compounds used in this invention may be readily prepared, where appropriate, by reacting the free acid form of said compound with an appropriate base, usually one equivalent, in a co-solvent. Typical bases are sodium hydroxide, sodium methoxide, sodium ethoxide, sodium hydride, potassium methoxide, magnesium hydroxide, calcium hydroxide, benzathine, choline, diethanolamine, piperazine and tromethamine. The salt is isolated by concentration to dryness or by addition of a non-solvent. In many cases, salts are preferably prepared by mixing a solution of the acid with a solution of a different salt of the cation (sodium or potassium ethylhexanoate, magnesium oleate), and employing a solvent (e.g., ethyl acetate) from which the desired cationic salt precipitates, or can be otherwise isolated by concentration and/or addition of a non-solvent. [0202] The acid addition salts of the compounds used in this invention may be readily prepared by reacting the free base form of said compound with the appropriate acid. When the salt is of a monobasic acid (e.g., the hydrochloride, the hydrobromide, the p-toluenesulfonate, the acetate), the hydrogen form of a dibasic acid (e.g., the hydrogen sulfate, the succinate) or the dihydrogen form of a tribasic acid (e.g., the dihydrogen phosphate, the citrate), at least one molar equivalent and usually a molar excess of the acid is employed. However when such salts as the sulfate, the hemisuccinate, the hydrogen phosphate or the phosphate are desired, the appropriate and exact chemical equivalents of acid will generally be used. The free base and the acid are usually combined in a co-solvent from which the desired salt precipitates, or can be otherwise isolated by concentration and/or addition of a non-solvent. [0203] In addition, the growth hormone secretagogues and antidepressants which may be used in accordance with this invention, prodrugs thereof and pharmaceutically acceptable salts thereof or of said prodrugs, may occur as hydrates or solvates. Said hydrates and solvates are also within the scope of the invention. [0204] The utility of the combinations, pharmaceutical compositions, kits and methods of the present invention as medical agents in the treatment of musculoskeletal frailty (e.g., conditions which present with low bone mass or low muscle mass including osteoporosis) in mammals (e.g. humans) is demonstrated by the activity of the compounds of this invention in conventional assays as set forth in U.S. Pat. No. 5,552,412 and International Pat. Application Publication No. WO97/24369. Such assays also provide a means whereby the activities of the compositions of this invention can be compared between themselves and with the activities of other known compounds and/or compositions. The results of these comparisons are useful for determining dosage levels in mammals, including humans, for the treatment of such diseases. [0205] Administration of the compounds used in this invention can be via any method which delivers the compounds or the combination of this invention systemically and/or locally. These methods include oral, parenteral, intraduodenal routes, etc. Generally, the compounds used in this invention are administered orally, but parenteral administration (e.g., intravenous, intramuscular, transcutaneous, subcutaneous or intramedullary) may be utilized, for example, where oral administration is inappropriate for the instant target or where the patient is unable to ingest the drug. The two different compounds used in this invention can be co-administered simultaneously or sequentially in any order, or a single pharmaceutical composition comprising a first compound as described above and a second compound as described above in a pharmaceutically acceptable carrier can be administered. [0206] In any event the amount and timing of compounds administered will, of course, be dependent on the subject being treated, on the severity of the affliction, on the manner of administration and on the judgment of the prescribing physician. Thus, because of patient to patient variability, the dosages given below are a guideline and the physician may titrate doses of the drug to achieve the activity (e.g., muscle mass improvement, mental state improvement and/or metabolism improvement) that the physician considers appropriate for the individual patient. In considering the degree of activity desired, the physician must balance a variety of factors such as muscle mass starting level, cardiac output, age of the patient, presence of preexisting disease, other ongoing or planned medical treatments or procedures, as well as the presence of other diseases. The following paragraphs provide preferred dosage ranges for the various components of this invention. [0207] This invention relates both to methods of treating the physical and mental condition of a patient and/or to improve the cardiac function, metabolism and muscle condition of a patient in which the GHS and antidepressant are administered together, as part of the same pharmaceutical composition, and to methods in which these two agents are administered separately, as part of an appropriate dosage regimen designed to obtain the benefits of the combination therapy. The appropriate dosage regimen, the amount of each dose administered and the intervals between doses of the active agents will depend upon the GHS and the antidepressant being used, the type of pharmaceutical formulations being used, the characteristics of the subject being treated and the severity of the complications. Generally, in carrying out the methods of this invention, an effective dosage for the GHS compounds of this invention is in the range of 0.0002 to 2 mg/kg/day, preferably 0.01 to 1 mg/kg/day in single or divided doses. It is preferred that the dosage amount of said GHS is about 1 mg to about 50 mg per day for an average subject, depending upon the GHS and the route of administration. The GHS compound and the antidepressant will be administered in single or divided doses. The preferred dosage ranges for the antidepressants used in this invention will vary depending upon the particular antidepressant used. The preferred dosage amounts of the antidepressants are well known to those skilled in the art or can be found in the Physicians Desk References (PDR®), 54 th Edition, 2000, Medical Economics Company, Inc., Montvale, N.J., 07645 or in Goodman and Gilman's The Pharmacological Basis of Therapeutics, Hardman, Limbird, Molinoff, Ruddon and Gilman, Eds., 9 th Edition, 1996, McGraw-Hill, New York, pp. 433-435. For example, SSRIs will generally be administered in amounts ranging from about 0.05 mg/kg/day to about 10 mg/kg/day in single or divided doses, preferably 5 mg to about 500 mg per day for an average subject, depending upon the SSRI and the route of administration. However, some variation in dosage will necessarily occur depending on the condition of the subject being treated. The prescribing physician will, in any event, determine the appropriate dose for the individual subject. [0208] Pharmaceutical compositions comprising a growth hormone secretagogue, a prodrug thereof or a pharmaceutically acceptable salt of said growth hormone secretagogue or said prodrug and an antidepressant, a prodrug thereof or a pharmaceutically acceptable salt of said antidepressant or said prodrug are hereinafter referred to, collectively, as “the active compositions of this invention.” [0209] Where the tartrate salt, hydrochloride salt or other pharmaceutically acceptable salt of any of the above compounds is used in this invention, the skilled person will be able to calculate effective dosage amounts by calculating the molecular weight of the salt form and performing simple stoichiometric ratios. [0210] The compounds, prodrugs and pharmaceutically acceptable salts used in the combinations of the present invention are generally administered in the form of a pharmaceutical composition comprising at least one of the compounds or pharmaceutically acceptable salts thereof of this invention together with a pharmaceutically acceptable vehicle or diluent. Thus, the compounds, prodrugs and pharmaceutically acceptable salts thereof of this invention can be administered separately or together in any conventional oral, parenteral or transdermal dosage form. When administered separately, the administration of the other compound or a pharmaceutically acceptable salt thereof of the invention follows. [0211] For oral administration a compound or pharmaceutical composition can take the form of solutions, suspensions, tablets, pills, capsules, powders, and the like. Tablets containing various excipients such as sodium citrate, calcium carbonate and calcium phosphate are employed along with various disintegrants such as starch and preferably potato or tapioca starch and certain complex silicates, together with binding agents such as polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, sodium lauryl sulfate and talc are often useful for tableting purposes. Solid compositions of a similar type are also employed as fillers in soft and hard-filled gelatin capsules; preferred materials in this connection also include lactose or milk sugar as well as high molecular weight polyethylene glycols. When aqueous suspensions and/or elixirs are desired for oral administration, the compounds or pharmaceutically aceptable salts thereof of this invention can be combined with various sweetening agents, flavoring agents, coloring agents, emulsifying agents and/or suspending agents, as well as such diluents as water, ethanol, propylene glycol, glycerin and various like combinations thereof. [0212] For purposes of parenteral administration, solutions in sesame or peanut oil or in aqueous propylene glycol can be employed, as well as sterile aqueous solutions of the corresponding water-soluble salts. Such aqueous solutions may be suitably buffered, if necessary, and the liquid diluent first rendered isotonic with sufficient saline or glucose. These aqueous solutions are especially suitable for intravenous, intramuscular, subcutaneous and intraperitoneal injection purposes. In this connection, the sterile aqueous media employed are all readily obtainable by standard techniques well-known to those skilled in the art. [0213] For purposes of transdermal (e.g., topical) administration, dilute sterile, aqueous or partially aqueous solutions (usually in about 0.1% to 5% concentration), otherwise similar to the above parenteral solutions, are prepared. [0214] Methods of preparing various pharmaceutical compositions with a certain amount of each active ingredient are known, or will be apparent in light of this disclosure, to those skilled in this art. For examples, see Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., 19th Edition (1995). [0215] Pharmaceutical compositions according to the invention may contain 0.1%-95% of a combination of the compounds, prodrugs or pharmaceutically acceptable salts thereof used in this invention, preferably 1%-70%. In any event, the composition or formulation to be administered will contain a quantity of a combination of the compounds, prodrugs or pharmaceutically acceptable salts thereof used in the invention in an amount effective to treat the disease/condition of the subject being treated. [0216] Since the present invention relates to treatment with a combination of the two active ingredients which may be administered separately, the invention also relates to combining separate pharmaceutical compositions in kit form. The kit includes two separate pharmaceutical compositions: a GHS, a prodrug thereof or a pharmaceutically acceptable salt thereof or of said prodrug and an antidepressant, a prodrug thereof or a pharmaceutically acceptable salt thereof or of said prodrug. The kit includes a container for containing the separate compositions such as a divided bottle or a divided foil packet, however, the separate compositions may also be contained within a single, undivided container. Typically the kit includes directions for the administration of the separate components. The kit form is particularly advantageous when the separate components are preferably administered in different dosage forms (e.g., oral and parenteral), are administered at different dosage intervals, or when titration of the individual components of the combination is desired by the prescribing physician. [0217] An example of such a kit is a so-called blister pack. Blister packs are well known in the packaging industry and are being widely used for the packaging of pharmaceutical unit dosage forms (tablets, capsules, and the like). Blister packs generally consist of a sheet of relatively stiff material covered with a foil of a preferably transparent plastic material. During the packaging process recesses are formed in the plastic foil. The recesses have the size and shape of the tablets or capsules to be packed. Next, the tablets or capsules are placed in the recesses and the sheet of relatively stiff material is sealed against the plastic foil at the face of the foil which is opposite from the direction in which the recesses were formed. As a result, the tablets or capsules are sealed in the recesses between the plastic foil and the sheet. Preferably the strength of the sheet is such that the tablets or capsules can be removed from the blister pack by manually applying pressure on the recesses whereby an opening is formed in the sheet at the place of the recess. The tablet or capsule can then be removed via said opening. [0218] It is desirable to provide a memory aid on a card insert, e.g., in the form of numbers next to the tablets or capsules whereby the numbers correspond with the days of the regimen which the tablets or capsules so specified should be ingested. Another example of such a memory aid is a calendar printed on the card e.g., as follows “First Week, Monday, Tuesday, . . . etc . . . Second Week, Monday, Tuesday, . . . ” etc. Other variations of memory aids will be readily apparent. A “daily dose” can be a single tablet or capsule or several pills or capsules to be taken on a given day. Also a daily dose of antidepressant can consist of one tablet or capsule while a daily dose of a GHS can consist of several tablets or capsules and vice versa. The memory aid should reflect this. [0219] In another specific embodiment of the invention a dispenser designed to dispense the daily doses one at a time in the order of their intended use is provided. Preferably, the dispenser is equipped with a memory-aid, so as to further facilitate compliance with the regimen. An example of such a memory-aid is a mechanical counter which indicates the number of daily doses that has been dispensed. Another example of such a memory-aid is a battery-powered micro-chip memory coupled with a liquid crystal readout, or audible reminder signal which, for example, reads out the date that the last daily dose has been taken and/or reminds one when the next dose is to be taken. [0220] It should be understood that the invention is not limited to the particular embodiments described herein, but that various changes and modifications may be made without departing from the spirit and scope of this invention as defined by the following claims.

This invention is directed to combinations comprising a growth hormone secretagogue, a prodrug thereof or a pharmaceutically acceptable salt of said growth hormone secretagogue or said prodrug and an antidepressant, a prodrug thereof or a pharmaceutically acceptable salt of said antidepressant or said prodrug and to pharmaceutical compositions and kits comprising such combinations. Antidepressants within the scope of this invention include norepinephrine reuptake inhibitors (e.g., secondary and tertiary amine tricyclics), selective sertraline reuptake inhibitors, agents which are combined norepinephrine/sertraline reuptake inhibitors, monoamine oxidase inhibitors and atypical antidepressants. This invention is also directed to methods of improving the physical and/or psychological condition of a patient undergoing a medical procedure, to methods of treating musculoskeletal frailty, to methods of treating congestive heart failure and to methods of attenuating protein catabolic response after a major operation comprising administering such a combination. In particular, this invention relates to such compositions and kits that improve the cardiac function, metabolism, muscle tone and/or mental state of patients undergoing a medical procedure. The compositions and kits of this invention are also useful in treating central nervous system disorders of patients undergoing a medical procedure.

The invention herein described was made in the course of or under a contract with the Department of the Air Force. BACKGROUND OF THE INVENTION This invention relates to a device for minimizing the clearance between blade tips and surrounding shroud. In this art, many different types of shroud have been used. A sample of these are shown by U.S. Pat. Nos. 3,391,904; 2,859,934; 3,443,791 and 3,742,705. Turbine blade tip clearance is difficult to control because blade tip growth is made up of two elements that are different in thermal response rate; the blade responds rapidly while the disk responds more slowly. Presently, attempts are made to control blade tip clearance by trying to duplicate blade tip growth with a third element. SUMMARY OF THE INVENTION A primary object of the present invention is to improve thermal growth compatibility between blade tips and shroud to reduce interference and increase engine performance. In accordance with the present invention the shroud position is governed by movement of the vanes which reduce tip clearance change to surge or aircraft maneuvers. It is an object of this invention to improve the gas path seal between the blade and vane platforms at their internal diameter. A further object of this invention is to provide shroud arrangement in which the blade tip shroud is responsive to vane internal diameter support, wherein the internal diameter vane support acts as a disk growth simulator and the vane acts as a blade growth simulator. The internal diameter support of the vane can have its response rate adjusted by changing its heat transfer convection rate; this can be done by controlling the material of the support and its shielding and cooling. Another object of this invention is to provide for growth of the outer diameter of the vane within the turbine casing so that the movement of the outer diameter of the vane is not affected by the growth of the case. A further object of this invention is to provide cooling means in the blade tip shroud to further aid in eliminating shroud warping. The flow can be injected onto a sheet metal seal to eliminate direct impingement cooling on the shroud itself. Coolant flow spaces were made spherical to reduce conduction into the sheet metal seal. Another object of the invention is to provide a shroud support which is not integral with the vanes, yet radial growth is controlled by the vanes. This allows tilt of the shrouds to be controlled independently of the tilts of the vanes. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of the invention showing the rotor discs and blades and the stationary vanes along with the supporting structure. FIG. 2 is a modification of the arrangement shown in FIG. 1. FIG. 3 is a modification of the arrangement shown in FIG. 2. DESCRIPTION OF THE PREFERRED EMBODIMENT The turbine section 11 shown in FIG. 1 is located in the same environment as the turbine section of U.S. Pat. No. 3,826,084. This turbine section 11 comprises a gas path having first stage vanes 18, first stage blades 42, second stage vanes 80, and second stage blades 62. The first stage vanes 18 are mounted in pairs of two between inner shroud segments 17 and outer shroud segments 19. There could be 23 shroud segments 17 and 19 forming comlete inner and outer shrouds, with a total of 46 blades. The inner shroud segments 17 each have an inwardly extending flange 20 adjacent its rearward end with a rearwardly extending foot 22 at its inner extremity. An inner support flange 30 extending outwardly from fixed inner structure on the engine has a forwardly facing annular groove 24 thereon which is positioned to receive the feet 22 of the first stage vanes 18. Projections 26 extend forwardly from the inner support flange 30, one for each pair of vanes 18 with each projection having an outwardly extending positioning projection 28 which engages a notch 32 in a short inwardly extending projection at the forward part of inner shroud section 17. This positions the first stage vanes 18 around the inner support flange 30. The inner ends of each pair of vanes 18 are held in place by member 3a which is fixed to the outer end of the projection 26 and contacts the forward face of the inner shroud segment 17. The outer shroud segments 19 each have an outwardly extending flange 34 adjacent its forward end and outwardly extending flange 36 at its rearward end. These flanges are positioned between an inwardly extending annular flange 38 on casing 10 and an inwardly extending annular resilient flange 44 which is held at its outer edge between two sections of the casing 10. The rear end of burner means (not shown) is sealed by flange members 3 and 5 which extend forwardly from the forward part of the turbine section 11. Flange members 3 are fixed to the projections 26 while flange members 5 are fixed to the flange member 44. This flange member 5 can be riveted to the flange 44. The first stage blades 42 have roots 12 which are positioned in slots on the outer periphery of a first stage rotor disk 40. The blades 42 each have a platform 48 which form with each other an inner annular member. The forward edge of the blade platforms 48 are positioned adjacent the rearward edges of the inner shroud segments 17 to form a gas path seal at that point. Side plates 50 and 52 are fixed to the disc 40 to retain the blade roots of all the blades therein. A second stage rotor disc 60 is positioned rearwardly of rotor disc 40. Rotor disc 60 has second stage blades 62 mounted thereon with roots 14 positioned in slots on the outer periphery thereof, in a manner similar to that used on rotor 40. A cylindrical spacing and seal member 64 extends between the rotor discs 40 and 60. The forward end of the member 64 has an outwardly extending flange 54 which is fixed to the disc 40 and positioned over the side plate 50. The rear end of the member 64 has an outwardly extending annular flange member 56 which forms a side plate for the front of the rotor disc 60. A tang 58 integral with the blade root contacts the front of rotor disc 60 to retain the blade roots of all of the blades with side plate 56. The blades 62 each have a platform 66 which form with each other an inner annular member. A plurality of second stage vanes 80 are positioned between the first stage blades 42 and the second stage blades 62. The second stage vanes 80 are mounted in pairs of two between inner shroud segments 82 and outer shroud segments 84. The inner shroud segments 82 of vanes 80 are each fixed at their inner ends to a ring 68 which is positioned around projects 70 on member 64. The outer tips of these projections 70 form a seal with the inner surface of the ring member 68. A flange 72 extends inwardly from each inner shroud segment 82 and has a forwardly positioned groove 74 therein. The grooves 74 of each flange 72 form an annular groove which receives an annular flange member 76 which extends rearwardly from ring 68. This positions the inner ends of the second stage vanes 80 in a radial direction. The ring 68 is fixed in relation to the flange 72 to prevent relative axial movement therebetween. While this is shown by the use of a holding bracket 78, other means can be used if desired. A flange member 90 extends forwardly from each outer shroud segment 84. These flange members 90 form an annular outer shroud around the blade tips of the first stage blades 42. The forward ends of the flange members 90 are received in a rearwardly facing slot 92 formed in the outwardly extending flange 36 at the rearward end of the first stage vanes 18. These slots are located radially inward from the inner end of the annular flange 38. A space "A" is provided for a differential in radial movement between the flange member 90 and the inner end of flange 38. A flange member 94 extends rearwardly from each outer shroud segment 84. These flange members 94 form an annular outer shroud around the blade tips of the second stage blades 62. The rearward ends of the flange members 94 are positioned adjacent a wall 96 which is fixed to the casing 10 and provides the outer surface which guides the gas flow through the turbine section. Each second stage vane 80 projects outwardly from the outer shroud segments 84 at 98. The outwardly projecting portion 98 is guided radially between a flange 100 extending inwardly from casing 10 and a flange 102 extending inwardly from said casing 10. To center the ring member 68, a plurality of second stage vanes 80 each having a lug 104 projecting radially outwardly which fits into a cooperating notch 106 formed on the casing 10. This scheme also provides closely controlled gas path seals between shroud members 48 and 82 and also between 82 and 66. In the modification of the invention as shown in FIG. 2, the inner diameter of the first stage vane 18A is fixed in the same manner as the first stage vane 18 of FIG. 1, and the first stage blade 42A is formed in the same manner as blade 42 of FIG. 1 and can have the same type of blade connection and rotor disc. The outer diameter of the first stage vane 18A is constructed similar to the one shown in FIG. 1 except that each flange 36A has a rearwardly extending integral flange member 37. These flange members 37, which form a ring, carry a plurality of separate shroud members 39. The forward ends of the shroud members 39 fit in a groove 92A formed in the outwardly extending flanges 36A inside of the flange member 37. The rear end of the flange member 37 extends into a forwardly facing slot 41 located in an outwardly extending flange 43. To provide for sealing a coolant flow from a chamber 45 to the interior of each shroud member 39, a multl-piece annular sheet metal seal 130 is positioned between the inner surface of the flange members 37 and the outer surface of the separate shroud members 39. A sheet metal shroud such as shown here is disclosed in U.S. Pat. No. 3,836,279. The sheet metal seal is formed having a raised portion 136 around the edge thereof to provide a biasing force between the members 37 and 39. The seal 130 is built so as to provide a chamber 132 between the members 37 and 130, and the outer surface of the members 39 are provided with a plurality of raised nodules or bumps 134 on which the inner surface of seal 130 rests. It can be seen that a fluid under pressure entering the cavity 45 will flow through a passageway 47 in each flange 36A and flange member 37 into each chamber 132 at its forward end where it is directed to the other side of the seal 130 at its rearward end through an opening 133 where it flows by and around the raised nodules or bumps 134 through a passageway 51, the space between the forward end of member 39 and bottom of groove 92A to passageway 53 to the upstream end of the blade tip 42A. A sheet metal seal 55 is located between the rear end of the shroud members 39 and the forward part of a flange 81A at the outer diameter of the second stage vanes 80A. This seal 55 extends outwardly to a location between a T-shaped member 57 extending inwardly from casing 10 and the forward part of flange 81A. An annular spacer member 61 is provided with an inwardly projecting annular groove 63 which receives an outwardly extending flange 65 positioned outwardly from the rear end of each pair of vanes 18A. The spacer 61 is provided with an outwardly extending annular flange 65 at its rearward end which abuts the forward part of the T-shaped member 57 to axially position the vane and shroud assembly. In the modification of the invention as shown in FIG. 3, the inner diameter of the first stage vane 18B is fixed in the same manner as the first stage vane 18 of FIG. 1, and the first stage blade 42B is formed in the same manner as blade 42 of FIG. 1 and can have the same type of blade connection and rotor disc. The outer diameter of the first stage vane 18B is constructed similar to the one shown in FIG. 2 except that the shroud support member 37B is not integral therewith. These shroud support members 37B, which form a ring, carry a plurality of separate shroud members 39B. The forward ends of the members 39B and 37B fit in a groove 92B, formed in the outwardly extending flanges 36B. The rear end of the shroud support member 37B extends into a forwardly facing slot 41B located in an outwardly extending flange 43B. To provide for sealing a coolant flow from a chamber 45B to the interior of each shroud member 39B, a multi-piece annular sheet metal seal 130B is positioned between the inner surface of the shroud support members 37B and the outer surface of the separate shroud members 39B. A sheet metal shroud such as shown here is disclosed in U.S. Pat. No. 3,836,279. The sheet metal seal is formed having a raised portion 136B around the edge thereof to provide a force biasing the members 37B and 39B apart. The seal 130B is built so as to provide a chamber 132B between the member 37B and 130B, and the outer surface of the members 39B are provided with a plurality of raised nodules or bumps 134B on which the inner surface of seal 130B rests. The cooling flow passes from cavity 45B to the blade tips in the same manner as shown in FIG. 2. A sheet metal seal 55B is located between the rear end of the shroud members 39B and the forward part of a flange 81B at the outer diameter of the second stage vanes 80B. This seal 55B extends outwardly to a location between a projecting member 57B extending inwardly from casing 10 and the forward part of flange 81B. An annular spacer member 61B is provided with an inwardly projecting annular flange 64B which fits into a groove 66B positioned to open outwardly from the rear end of each shroud support member 37B. The spacer 61B is provided with an abutment 68B at its rearward end which abuts the forward part of the member 57B to axially position the vane and shroud assembly. The main additional feature of FIG. 3 over FIG. 2 is that the shroud support member 37B is not integral with the vanes. This allows axial tilt of the shrouds to be controlled independently of the vanes axial tilt, yet radial growth is controlled by the vanes. In this modification, to aid in maintaining the shroud support member 37B perpendicular to the engine center line it is made up of four (4) sections. It is noted that there is one shroud member 39B for each two vanes and that the spacer 61B is annular. It is noted that the passageways 53 are located at an angle so that the fluid passing therethrough exits in a direction matching the flow exiting from the vanes 18A to increase the efficiency of the turbine.

This invention shows a shroud construction located around the tips of the blades on a rotating body in an engine to provide a minimum clearance between the blade tips and the shroud during all conditions of operation-acceleration, steady state and deceleration. This shroud construction provides an arrangement where the internal diameter of the vanes support the shroud member for the tips of the blades. The vane is supported as internal diameter to an internal support while the outer diameter of the vane is permitted radial growth with respect to the turbine casing. While the blade tip shroud can be made integral with the outer shroud of the vanes, it may be connected by means which will permit a small axial misalignment. Means are provided for cooling the shrouds around the tips of the blades.

[0001] This application is a divisional of prior application Ser. No. 13/466,956, filed May 8, 2012, currently pending; TECHNICAL FIELD [0002] The invention relates generally to power splitters or combiners and, more particularly, to terminationless power splitters or combiners. BACKGROUND [0003] In radio frequency (RF) applications, it is commonplace to split and/or combine signals, and there are a variety of ways in which this can be accomplished. One example is a Wilkinson splitter/combiner 100 , which can be seen in FIG. 1 . Typically, a Wilkinson splitter (or combiner) 100 is a 2-to-1 splitter (or combiner) having input port WIN and output ports WOUT 1 and WOUT 2 . The distances D 2 and D 3 along the outer diameter of the splitter 100 is on the order of one-quarter of the wavelength for the frequency-of-interest, and the distance D 1 along the inner diameter of the splitter 100 is on the order of one-half the wavelength for the frequency-of-interest. Additionally, an impedance element (i.e., resistor) 102 is coupled between ports WOUT 1 and WOUT 2 to allow for isolation and proper impedance matching. [0004] In another alternative approach, a hybrid coupler or rat-race 200 (as shown in FIG. 2 ) can be employed. As shown, this coupler 200 is generally curvilinear (i.e. circular) with an inner diameter (which can, for example, be one and one-half the wavelength of the frequency-of interest). This coupler 200 has an input port RIN and output port ROUT 1 and ROUT 2 (which are capable of outputting signals outputting signals at approximately one-half the input power). Additionally, there is an isolation port RISO that is terminated with an impedance element (i.e., resistor) 202 . [0005] Each of these different approaches can be adequate under appropriate conditions (i.e., <10 GHz); however, for high speed applications (i.e. terahertz or millimeter wave), these approaches may not be adequate. In particular, the physical terminations (i.e., impedance elements 102 and 202 ) may be prohibitive in terms of both cost and size. Therefore, there is a need for an improved combiner/splitter. [0006] Some examples of conventional systems are: U.S. Pat. No. 4,254,386; U.S. Pat. No. 4,956,621; U.S. Pat. No. 6,674,410; and European Patent No. EP1042843. SUMMARY [0007] The present invention, accordingly, provides an apparatus. The apparatus comprises a first hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the first hybrid coupler is a first isolation port, and wherein the first port of the first hybrid coupler is configured to carry a first portion of a differential signal, and wherein the first hybrid coupler is substantially curvilinear; and a second hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the second hybrid coupler is a second isolation port, and wherein the first port of the second hybrid coupler is configured to carry a second portion of the differential signal, and wherein the second hybrid coupler is substantially curvilinear, and wherein the first and second isolation ports are mutually coupled. [0008] In accordance with the present invention, the apparatus further comprises: a third hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the third hybrid coupler is a third isolation port, and wherein the first port of the third hybrid coupler is configured to carry the first portion of the differential signal, and wherein the third hybrid coupler is substantially curvilinear; and a fourth hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the fourth hybrid coupler is a fourth isolation port, and wherein the first port of the fourth hybrid coupler is configured to carry the second portion of the differential signal, and wherein the fourth hybrid coupler is substantially curvilinear, and wherein the third and fourth isolation ports are mutually coupled. [0009] In accordance with the present invention, the first, second, third, and fourth couplers are symmetrically arranged. [0010] In accordance with the present invention, the apparatus further comprises: a substrate; and a metallization layer formed over the substrate, wherein the metallization layer is pattered to form the first, second, third, and fourth hybrid couplers. [0011] In accordance with the present invention, the third and fourth ports of the first hybrid coupler are coupled to a first antenna, and wherein the third and fourth ports of the second hybrid coupler are coupled to a second antenna, and wherein the third and fourth ports of the third hybrid coupler are coupled to a third antenna, and wherein the third and fourth ports of the fourth hybrid coupler are coupled to a fourth antenna. [0012] In accordance with the present invention, the metallization layer further comprises a first metallization layer, and wherein the first, second, third, and fourth antennas further comprises: a first set of vias formed over the first metallization layer, wherein each via from the first set of vias is electrically coupled to at least one of the second ports from the first, second, third, and fourth hybrid couplers; a second set of vias formed over the first metallization layer, wherein each via from the second set of vias is electrically coupled to at least one of the third ports from the first, second, third, and fourth hybrid couplers; and a second metallization layer formed over the first and second sets of vias and patterned to form portions of the first, second, third, and fourth antennas. [0013] In accordance with the present invention, the apparatus further comprises: a third set of vias formed between the first metallization layer and the substrate, wherein each via from the third set of vias is electrically coupled to at least one of the fourth ports from the first, second, third, and fourth hybrid couplers; and a third metallization layer formed between the substrate and the first metallization layer, wherein the third metallization layer is patterned such that the mutual coupling between the first and second hybrid couplers and the mutual coupling between the third and fourth hybrid couplers are electrical couplings. [0014] In accordance with the present invention, the apparatus further comprises a third metallization layer formed between the first metallization layer and the substrate. [0015] In accordance with the present invention, a method is provided. The method comprises forming a metallization layer formed over a substrate; and patterning the metallization layer to form: a first hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the first hybrid coupler is a first isolation port, and wherein the first port of the first hybrid coupler is configured to carry a first portion of a differential signal, and wherein the first hybrid coupler is substantially curvilinear; a second hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the second hybrid coupler is a second isolation port, and wherein the first port of the second hybrid coupler is configured to carry a second portion of the differential signal, and wherein the second hybrid coupler is substantially curvilinear, and wherein the first and second isolation ports are mutually coupled; a third hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the third hybrid coupler is a third isolation port, and wherein the first port of the third hybrid coupler is configured to carry the first portion of the differential signal, and wherein the third hybrid coupler is substantially curvilinear; and a fourth hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the fourth hybrid coupler is a fourth isolation port, and wherein the first port of the fourth hybrid coupler is configured to carry the second portion of the differential signal, and wherein the fourth hybrid coupler is substantially curvilinear, and wherein the third and fourth isolation ports are mutually coupled. [0016] In accordance with the present invention, the metallization layer further comprises a first metallization layer, and wherein the method further comprises forming first, second, third, and fourth antennas by: forming a first set of vias over the first metallization layer, wherein each via from the first set of vias is electrically coupled to at least one of the second ports from the first, second, third, and fourth hybrid couplers; forming a second set of vias over the first metallization layer, wherein each via from the second set of vias is electrically coupled to at least one of the third ports from the first, second, third, and fourth hybrid couplers; and forming a second metallization layer over the first and second sets of vias and patterned to form portions of the first, second, third, and fourth antennas. [0017] In accordance with the present invention, the method further comprises: forming a third set of vias between the first metallization layer and the substrate, wherein each via from the third set of vias is electrically coupled to at least one of the fourth ports from the first, second, third, and fourth hybrid couplers; and forming a third metallization layer between the substrate and the first metallization layer, wherein the third metallization layer is patterned such that the mutual coupling between the first and second hybrid couplers and the mutual coupling between the third and fourth hybrid couplers are electrical couplings. [0018] In accordance with the present invention, the method further comprises forming a third metallization layer between the first metallization layer and the substrate. [0019] In accordance with the present invention, an apparatus comprising: an integrated circuit (IC); and an antenna package that is secured to the IC, wherein the antennal package includes: a first hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the first hybrid coupler is a first isolation port, and wherein the first port of the first hybrid coupler is configured to carry a first portion of a differential signal, and wherein the first hybrid coupler is substantially curvilinear, and wherein the first port of the first hybrid coupled is coupled to the IC; a second hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the second hybrid coupler is a second isolation port, and wherein the first port of the second hybrid coupler is configured to carry a second portion of the differential signal, and wherein the second hybrid coupler is substantially curvilinear, and wherein the first and second isolation ports are mutually coupled, and wherein the first port of the second hybrid coupled is coupled to the IC; a third hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the third hybrid coupler is a third isolation port, and wherein the first port of the third hybrid coupler is configured to carry the first portion of the differential signal, and wherein the third hybrid coupler is substantially curvilinear, and wherein the first port of the third hybrid coupled is coupled to the IC; a fourth hybrid coupler having a first port, a second port, a third port, and a fourth port, wherein the fourth port of the fourth hybrid coupler is a fourth isolation port, and wherein the first port of the fourth hybrid coupler is configured to carry the second portion of the differential signal, and wherein the fourth hybrid coupler is substantially curvilinear, and wherein the third and fourth isolation ports are mutually coupled, and wherein the first port of the fourth hybrid coupled is coupled to the IC; a first antenna that is coupled to the third and fourth ports of the first hybrid coupler; a second antenna that is coupled to the third and fourth ports of the second hybrid coupler; a third antenna that is coupled to the third and fourth ports of the third hybrid coupler; and a fourth antenna that is coupled to the third and fourth ports of the fourth hybrid coupler. [0020] In accordance with the present invention, the antenna package further comprises: a substrate; a first metallization layer formed over the substrate; a second metallization layer formed over the first metallization layer, wherein the second metallization layer is pattered to form the first, second, third, and fourth hybrid couplers; a first set of vias formed over the second metallization layer, wherein each via from the first set of vias is electrically coupled to at least one of the second ports from the first, second, third, and fourth hybrid couplers; a second set of vias formed over the second metallization layer, wherein each via from the second set of vias is electrically coupled to at least one of the third ports from the first, second, third, and fourth hybrid couplers; and a third metallization layer formed over the first and second sets of vias and patterned to form portions of the first, second, third, and fourth antennas. [0021] In accordance with the present invention, the antenna package further comprises a high impedance surface (HIS) that substantially surrounds the first, second, third, and fourth antennas. [0022] In accordance with the present invention, the antenna package further comprises: a substrate; a first metallization layer formed over the substrate; a first set of vias formed over the first metallization layer; a second metallization layer formed over the first set of vias, wherein the second metallization layer is pattered to form the first, second, third, and fourth hybrid couplers, and wherein the first metallization layer is patterned to form electrical coupling between first and second isolation ports and the third and fourth isolation ports, and wherein each via from the firs set of vias is electrical coupled to at least one of the first, second, third, and fourth isolation ports; a second set of vias formed over the second metallization layer, wherein each via from the second set of vias is electrically coupled to at least one of the second ports from the first, second, third, and fourth hybrid couplers; a third set of vias formed over the second metallization layer, wherein each via from the third set of vias is electrically coupled to at least one of the third ports from the first, second, third, and fourth hybrid couplers; and a third metallization layer formed over the second and third sets of vias and patterned to form portions of the first, second, third, and fourth antennas. [0023] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS [0024] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: [0025] FIG. 1 is a diagram of an example of a convention Wilkinson splitter/combiner; [0026] FIG. 2 is a diagram of an example of a conventional hybrid coupler; [0027] FIG. 3 is a diagram of an example of a hybrid coupler in accordance with the present invention; [0028] FIG. 4 is a diagram of an example of a system implementing the hybrid coupler of FIG. 2 ; [0029] FIG. 5 is a plan view of an example of the antenna package of FIG. 4 [0030] FIGS. 6 and 16 are a plan view of examples of a metallization layer of the antenna package of FIG. 4 ; [0031] FIG. 7 is a cross-sectional view of the antenna package along section line I-I; [0032] FIG. 8 is a plan view of an example of a metallization layer of the antenna package of FIG. 4 ; [0033] FIGS. 9-11 are cross-sectional views of the antenna package along section line II-II, III-III, and IV-IV, respectively; [0034] FIG. 12 is a plan view of an example of a metallization layer of the antenna package of FIG. 4 ; [0035] FIG. 13 is a cross-sectional view of the antenna package along section line V-V; [0036] FIG. 14 is a plan view of an example of a metallization layer of the antenna package of FIG. 4 ; and [0037] FIG. 15 is a cross-sectional view of the antenna package along section line VI-VI. DETAILED DESCRIPTION [0038] Refer now to the drawings wherein depicted elements are, for the sake of clarity, not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views. [0039] Turning to FIG. 3 , an example of a differential coupler 300 in accordance with the present invention can be seen. As shown, this differential coupler 300 is generally comprised of hybrid couplers 302 and 304 with a mutual coupling between their respective isolation ports. This mutual coupling can be accomplished electrically coupling the isolation ports (i.e., via a wire or trace) or by virtue of a symmetric layout. By having the mutual coupling, termination is achieved by “zero action” where each of the hybrid couplers 302 and 304 mutually terminate one another. This allows a full power differential to be carried (i.e., input if coupler 300 is a splitter and output if coupler 300 is a combiner) by terminals INM and INP and one-half power signals carried by terminals OUTM 1 , OUTM 2 , OUTP 1 , and OUTP 2 . [0040] In FIGS. 4 and 5 , an example implementation for the coupler 300 can be seen. In this implementation, the coupler 300 is employs as part of the antenna package 404 of the terahertz or millimeter transmitter (which can transmit or receive RF signals in the range of 0.1 THz to 10 THz). The antenna package 202 (which, as shown, is coupled to printed circuit board or PCB 402 through solder balls (i.e., 408 ) to allow other integrated circuits (ICs) secured to the PCB 402 to communicate with IC 406 . IC 406 (which is secured to antenna package 406 ) includes an on-chip terahertz or millimeter wave transmitter is electrically coupled to a feed network (of which the coupler 300 is a part) and antennas. An example of a terahertz transmitter can be seen in U.S. patent application Ser. No. 12/878,484, which is entitled “Terahertz Phased Array System,” and which is incorporated by reference herein for all purposes. [0041] Typically, the antenna package 404 , itself, is a multiplayer PCB or IC where the feed network and antennas are built in layers. As shown in FIG. 5 , there can, for example, be antenna array 504 located substantially at the center of the antenna package 404 . This antenna array 504 can be surrounded by a high impedance surface (HIS) to improve transmission and reception characteristics, and an example of an HIS can be seen in U.S. patent application Ser. No. 13/116,885, which in entitled “High Impedance Surface,” and which is incorporated by reference herein for all purposes. As shown, the antenna array 504 is comprised of four antennas 506 - 1 to 506 - 4 arranged in a 2×2; other array densities (i.e., number of antennas) may also be employed. [0042] Now, turning to FIGS. 4-15 , an example of the antenna array 404 can be seen in greater detail. In this example, a 4-to-1 coupler is employed to coupled differential feed terminals (which are generally coupled to IC 406 ) to antennas 506 - 1 to 506 - 2 . As shown, there is a metallization layer 604 (which can, for example, be formed of aluminum or copper) formed over a substrate 602 , which is patterned for form portions 606 - 1 and 606 - 2 that can form traces for electrical coupling between isolation ports for two couplers (i.e., 300 ). The portions 606 - 1 and 606 - 2 can be coupled to the isolation ports through vias 610 - 1 to 610 - 4 (which can, for example, be formed of tungsten) that can be formed in openings of dielectric layer 612 (which can, for example, be silicon dioxide). Over the dielectric layer 612 (and vias 610 - 1 and 610 - 2 ), another metallization layer 614 (which can, for example, be formed of aluminum or copper) may be formed. This metallization layer 614 can be pattered to form hybrid couplers 611 - 1 to 611 - 4 that are arranged symmetrically with the differential feed terminals INM and INP being opposite of one another. As shown in this example, there is mutually coupling between the isolation ports of couplers 611 - 1 and 611 - 3 and between the isolation ports of couplers 611 - 2 and 611 - 4 . Also as shown, one port for each of hybrid couplers 611 - 1 and 611 - 2 can carry one portion of a differential input signal, while the other portion of the differential input signal can be carried by a port from each of couplers 611 - 3 and 611 - 4 . Each of these hybrid couplers 611 - 1 to 611 - 4 can then be coupled to antennas 506 - 1 to 506 - 4 , respectively. The antennas 506 - 1 to 506 - 4 can be formed by electrically coupling vias 616 - 1 to 616 - 8 to terminals of hybrid couplers 611 - 1 to 611 - 4 . Similar to other vias (i.e., 610 - 3 ), these vias 616 - 1 to 616 - 8 can formed of tungsten within openings of dielectric layer 617 (which can, for example, be silicon dioxide). Formed over dielectric layer 617 , there can be metallization layer 622 that can be patterned to form discs that are substantially coaxial with vias 616 - 1 to 616 - 8 . Another set of vias 624 - 1 to 624 - 8 can be formed in dielectric layer 626 , and can be substantially coaxial with vias 616 - 1 to 616 - 8 . Another metallization layer 628 (which may be formed aluminum of copper) can then be formed over dielectric layer 626 and can be pattered to form discs that are eccentrically aligned with 624 - 1 to 624 - 8 . These discs, in contrast to those of metallization layer 628 had nubs or fingers that are substantially aligned (i.e., aligned along two parallel lines). Alternatively, as shown in FIG. 16 , metallization layer 604 may be comprised of an unpatterned sheet and vias 610 - 1 to 610 - 4 may be omitted. [0043] Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.

An apparatus is provided. First and second hybrid couplers are provided with each having a first port, a second port, a third port, a fourth port and with each being substantially curvilinear. The fourth ports of the first and second hybrid couplers are first and second isolation port that are mutually coupled. The first port of the first hybrid coupler is configured to carry a first portion of a differential signal, and the first port of the second hybrid coupler is configured to carry a second portion of the differential signal.

BACKGROUND OF THE INVENTION [0001] The present invention is related to reduction gears and, in particular, to a carrier frame used in a planetary gear system. [0002] Gear reductions are often used in mechanical systems to provide a differential in the rates of rotation of an input shaft and an output shaft. Planetary gear assemblies are one example of such a reduction gear system. [0003] Planetary gear assemblies may include, for example, an input shaft having a sun gear arranged coaxially with an axis of rotation of the input shaft. Planetary gears engage the sun gear in a radial arrangement about the sun gear, and engage a fixed ring gear that is concentrically arranged about the sun gear. The planetary gears are arranged between the sun gear and the ring gear. The planetary gears are supported by bearings (generally two per gear, or two bearing sets) that are mounted in a carrier frame. These bearings are arranged in two planes with a bearing supporting each end of the planetary gear at each of these two planes. These planes are commonly arranged such that one is on either side of the gear so that the gear is straddle mounted (where gear face load occurs between bearings). The bearing centers are closely aligned between the two planes to establish an axis of rotation about their center that is parallel to the axis of rotation of the sun gear. [0004] In operation, a torsional force applied to the input shaft rotates the sun gear, which in turn, rotates the planetary gears that are coupled to the carrier frame resulting in the rotation of the carrier frame, and an output shaft connected to the carrier frame. The tooth count of each of the gears used collectively establishes the specific reduction ratio of the planetary gear assembly. BRIEF DESCRIPTION OF THE INVENTION [0005] According to an exemplary embodiment of the present invention, a planetary gear assembly includes a sun gear, planetary gears engaging the sun gear, a ring gear arranged about the planetary gears, the ring gear engaging the planetary gears, and a carrier frame including one or more pairs of bearing containment bands, a plurality of connecting segments, a plurality of spoke portions, and a hub portion, wherein each pair of bearing containment bands is connected to an adjacent pair of bearing containment bands with a connecting segment of the plurality of connecting segments and a spoke portion of the plurality of spoke portions connects each connecting segment to the hub portion. [0006] According to yet another exemplary embodiment of the present invention, a carrier frame of a planetary gear assembly, the carrier frame including one or more pairs of bearing containment bands, a plurality of connecting segments, a plurality of spoke portions, and a hub portion, wherein each pair of bearing containment bands is connected to an adjacent pair of bearing containment bands with a connecting segment of the plurality of connecting segments and a spoke portion of the plurality of spoke portions connects each connecting segment to the hub portion. BRIEF DESCRIPTION OF THE DRAWINGS [0007] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: [0008] FIG. 1 illustrates a perspective view of an exemplary embodiment of a planetary gear assembly. [0009] FIG. 2 illustrates a perspective view of the carrier frame, the planetary gears, and the supporting bearings of the gear assembly of FIG. 1 . [0010] FIG. 3 illustrates a perspective view of an exemplary embodiment of the carrier frame of FIGS. 1 and 2 . [0011] FIG. 4 illustrates another perspective view of the carrier frame of FIG. 3 . [0012] FIG. 5 illustrates a section view (side partially cut away) of the planetary gear frame arranged within an exemplary embodiment of a housing portion and gear train. [0013] FIG. 6 illustrates a perspective partially cut-away view of the carrier frame. DETAILED DESCRIPTION OF THE INVENTION [0014] FIG. 1 illustrates a perspective view of an exemplary embodiment of a planetary gear assembly 100 . The planetary gear assembly 100 includes a sun gear portion 102 coupled to an input shaft 104 . Planetary gears 106 engage the sun gear 102 , and are arranged radially about the sun gear 102 . The planetary gears 106 are coupled to bearings 108 that engage bearing containment bands 110 of a carrier frame 112 . The carrier frame 112 is connected to an output shaft 114 . An outer ring gear 116 engages the planetary gears 106 and is arranged concentrically about the sun gear 102 . [0015] In operation, the outer ring gear 116 may be fixed in position to, for example a housing portion (not shown). The input shaft 104 may be coupled to a device that provides a torque force such as, for example, an engine. When torque is applied to the input shaft 104 , the sun gear 102 rotates about the axis of rotation indicated by the arrow 101 . The rotation of the sun gear 102 in turn, drives the engaged planetary gears 106 such that the planetary gears 106 rotate about their respective axes of rotation indicated by the arrows 103 . The axes of rotation 103 of the planetary gears 106 are arranged substantially in parallel with the axis of rotation 101 of the sun gear 102 . The fixed arrangement of the outer ring gear 116 in engagement with the rotating planetary gears 106 results in the rotation of the carrier frame 112 , the output shaft 114 , and the collectively supported planetary gears 106 about an axis of rotation (indicated by the arrow 105 ) that is substantially coaxial with the axis of rotation indicated by the arrow 101 . [0016] In previous examples of carrier frames, a torque was applied to the input shaft, the resulting applied force is transmitted from the sun gear, to the planet gears, thru the bearing pairs, and onto the carrier frames. One plane of the bearings was coincident with the principle supporting plate, but the opposing plane of bearings were effectively moment loads (loads applied at a distance), which resulted in non-uniform torsional deflection of the carrier frame, creating misalignment of one bearing on a shaft relative to the other bearing. The illustrated exemplary embodiments of the carrier frame 112 described herein provide a carrier frame 112 that results in symmetric moment loading from bearings onto the carrier, which then exhibits uniform torsional deflection between bearing pairs when a torque is applied to the input shaft 104 . This outcome preserves suitable alignments between the bearing pairs supporting the planet gears, and thereby improving bearing life. The illustrated exemplary embodiments also requires less structural material and may be lighter than previous examples, thus providing additional benefits by reducing the amount of material resources used, and minimizing the total weight of the carrier frame. [0017] FIG. 2 illustrates a perspective view of the carrier frame 112 , the bearings 108 and the planetary gears 106 . The bearings 108 engage bearing containment bands 110 of the carrier frame 112 . The bearing containment bands 110 of the illustrated embodiment define an inner surface 201 and an outer surface 203 . The inner surface 201 defines an inner diameter that corresponds to an outer diameter of the bearings 108 . The outer surface 203 of each of the bearing containment bands 110 is connected to an adjacent outer surface 203 of a bearing wrap portion 110 by connecting segments 202 . A hub portion 204 having a conical profile includes connecting spokes 206 that extend radially from a portion 208 that connects to the output shaft 114 to connect to an inner surface 205 of the connecting segments 202 . The curved profile of the conical hub portion 204 facilitates clearance for the sun gear 102 (of FIG. 1 ) such that the hub portion 204 and spokes 206 do not interfere with the rotation of the sun gear 102 or the engagement of the sun gear 102 with the planetary gears 106 . In the illustrated embodiment, the carrier frame 112 is fabricated from a single piece of material such as, for example, steel, titanium, or aluminum. However, in alternate embodiments the carrier frame 112 may be fabricated from any number of separate components. The output shaft 114 is presented in this embodiment as being integrally formed with the carrier frame 112 , however alternate embodiments may provide a carrier frame 112 having a coupling or fastening portion operative to engage the output shaft 114 . The terms input shaft 104 and output shaft 114 are used for illustrative purposes. One of ordinary skill in the art would understand that an input force may be applied to either the input shaft 104 or output shaft 114 and, thus, the function of the respective shafts are interchangeable, and the terms input shaft 104 or output shaft 114 do not limit the functions of the shafts. [0018] FIG. 3 illustrates a perspective view of an exemplary embodiment of the carrier frame 112 of FIGS. 1 and 2 . FIG. 4 illustrates another perspective view of the carrier frame 112 of FIG. 3 . Referring to FIG. 4 , the bearing containment bands 110 are arranged in pairs that are spaced a distance d along a line that is substantially parallel to the axis of rotation indicated by the arrow 105 . The connecting segments 202 define a dimension x that is substantially parallel to the axis of rotation indicated by the arrow 105 . In the illustrated embodiment the distal ends 401 of the spokes 206 intersect and are connected to the inner surface 205 of corresponding connecting segments 202 at approximately the mid point of the dimension x. The positions of the intersections of the distal ends 401 of the spokes 206 with the connecting arc segment 202 affects the torsional deflection of the carrier frame 112 when a bearing reaction force is applied to the bearing containment bands 110 via the planetary gears 106 and bearings 108 (of FIG. 1 ). Though in the illustrated embodiment, the intersections of the distal ends 401 of the spokes 206 with the connecting segment 202 is arranged at approximately the mid point of the dimension x, alternate embodiments may arrange the intersections of the distal ends 401 of the spokes 206 with the connecting segment 202 in any position relative to the dimension x to optimize the reduction of torsional deflection of the carrier frame 112 when a force is applied to the bearing containment bands 110 via the planetary gears 106 . For example, it may be desirable to locate the intersections of the distal ends 401 of the spokes 206 with the connecting arc segment 202 in line, or substantially coplanar with the gear mesh plane (or center of the gear faces). In this regard, the intersection point may be determined based on system geometry, applied loads, and design goals for the carrier frame 112 . [0019] FIG. 5 illustrates a side partially cut away view of the presented planetary gear assembly 100 arranged in an exemplary embodiment of a housing portion 502 . In this regard, the outer ring gear 116 is secured to the housing portion 502 . The spokes 206 define an angle θ relative to the axis of rotation of the carrier frame 112 as indicated by the arrow 105 . The spokes 206 also define an angle θ′ relative to the inner surface of the 205 of the connecting segments 202 . In this illustrated embodiment, these angles are approximately supplements, though curvature of the connecting conical surface subtly influences the relationship between the angles. However, the connecting segments 202 may facilitate at any angle θ′ based on system packaging, production methods, operating loads, and tolerable deflection levels. [0020] FIG. 6 illustrates a perspective partially cut-away view of the carrier frame 102 . When a load is applied to the carrier frame 114 via the planetary gears 106 (of FIG. 1 ), the bearing reaction force is directed as indicated by the arrows 601 into the bearing containment bands 110 . The arrows 603 illustrate the structural path of the forces toward the output shaft 114 via the connecting segments 202 and the spokes 206 of the hub portion 204 . The arrangement of the intersections of the distal ends 401 of the spokes 206 with the connecting segment 202 at approximately the mid point of the dimension x provides equalized torsional deflection of the carrier frame 112 and improved planet bearing alignments when the force is applied as indicated by the arrows 601 . As discussed above, the intersections of the distal ends 401 of the spokes 206 with the connecting segment 202 may be arranged at any point along the dimension x (relative to the spacing of the bearing containment bands 110 in each of the pairs of bearing containment bands 110 ) to optimize the reduction of the torsional deflection of the carrier frame 112 . Thus, the relative torsional deflection of the carrier frame 112 can be influenced (e.g., balanced or equalized) if the intersections of the distal ends 401 of the spokes 206 with the connecting segment 202 are arranged, for example, in another position that is not equidistant from the planes defined by the surfaces 605 of the bearing containment bands 110 . [0021] Though the illustrated embodiments include a planetary gear assembly having five planetary gears, alternate embodiments may include a plurality of planetary gears having any number of planetary gears. [0022] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

A planetary gear assembly includes a sun gear, planetary gears engaging the sun gear, a ring gear arranged about the planetary gears, the ring gear engaging the planetary gears, and a carrier frame including one or more pairs of bearing containment bands, a plurality of connecting segments, a plurality of spoke portions, and a hub portion, wherein each pair of bearing containment bands is connected to an adjacent pair of bearing containment bands with a connecting segment of the plurality of connecting segments and a spoke portion of the plurality of spoke portions connects each connecting segment to the hub portion.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of producing connection electrodes for semiconductor integrated circuits, printed circuit substrates, glass substrates, flexible substrates, ceramic substrates or the like. 2. Description of the Related Art It is known that soldering is utilized in a method of electrically connecting the connection electrodes of such as a semiconductor chip to those of another circuit substrate. In the method utilizing soldering, a solder layer is formed on the electrodes of either of the substrates to be connected by plating, printing or other techniques. The solder layer is then heated to a high temperature of the order of 200°-250° C., and fused with the electrodes of the other substrate for connecting purposes. In this method, accordingly, it is necessary to employ a metal, such as Au, Cu or Ni, having an affinity for solder. However, it has been pointed out that such a high-temperature process utilizing soldering thermally damages circuit substrates and, in addition, the use of a metal having an affinity for solder leads to an increase in cost. The present applicant is aware of a method of electrically connecting the connection electrodes by using an anisotropic conductive sheet which includes conductive particles dispersed in an adhesive. This method can be used to solve the problems of thermal damage and cost increase. The anisotropic conductive sheet has anisotropy which exhibits electrical conductivity with respect to the direction in which pressure is applied to the sheet and also exhibits no electrical conductivity with respect to other directions. Specifically, in this method, such an anisotropic conductive sheet is inserted between electrodes, terminals or other portions to be connected. Then the portion of the sheet interposed between, for example, the electrodes, is pressed and heated in the direction of the thickness of the sheet, thereby forming the electrical connection between the electrodes. The anisotropic conductive sheet is particularly suitable for use in connecting the terminal electrodes of a liquid crystal display panel of the type which employs ITO (Indium Tin Oxide) as wiring material. This is because that high-temperature heat should not be applied to such liquid crystal display panel. The anisotropic conductive sheet has conductive particles dispersed throughout the entire resin serving as an adhesive. Accordingly, if adjacent electrode terminals are spaced close to one another an electrical short may occur due to the conductive particles. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method of producing connection electrodes which can prevent the occurrence of electrical shorts to improve the reliability of connection when connecting electrodes formed according to a micro pattern are connected. In order to achieve the above object, according to the present invention, there is provided a method of producing connection electrodes, which includes the steps of forming a resin layer made of a resin material capable of being softened after being hardened, on a circuit substrate on which an electrode pattern is formed, curing only the resin material on the electrode pattern, leaving only the resin layer on the electrode pattern, and adhering conductive particles to only the resin layer on the electrode pattern by softening the resin layer and scattering the conductive particles on the circuit substrate with the softened resin layer. According to the present invention, it is possible to dispose conductive particles on connection electrodes by a simple method. Accordingly, when handling micro electrode patterns, it is possible to improve the reliability with which the projections of respective electrodes which are formed of the conductive particles are connected to the electrodes of another circuit substrate by pressure bonding. In consequence, productivity increases and cost decreases. In the present invention, the curing step preferably includes a step of effecting illumination with ultraviolet rays through a mask having an opening pattern corresponding to the electrode pattern. The leaving step preferably includes a step of remove a non-cured part after the illumination with ultraviolet rays. This removing may be done by dissolving the non-cured part by a solvent. The adhering step preferably includes a step of removing the conductive particles attached to the portion other than the electrode pattern. This removing operation may be carried out after or simultaneously with the scattering the conductive particles. The adhering step preferably includes a step of scattering on the circuit substrate conductive particles each having a diameter greater than the thickness of the softened resin layer. The adhering step may include a step of scattering, on the circuit substrate, conductive particles each completely formed of metal. The adhering step may include a step of scattering, on the circuit substrate, conductive particles each of which is formed of an elastomeric particle coated with a metallic layer. Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view showing a part of a semiconductor device including connection electrodes formed according to a preferred embodiment of the present invention; FIG. 2 is a schematic cross-sectional view showing a part of a semiconductor device including connection electrodes formed according to another embodiment of the present invention; FIG. 3 is a cross-sectional view showing the structure of an example of a conductive particle; FIG. 4 is a cross-sectional view showing the structure of another example of the conductive particle; FIGS. 5a, 5b and 5c show steps in the preferred embodiment of the present invention; FIG. 6 is a schematic cross-sectional view showing a liquid-crystal display device on which is mounted a semiconductor device formed according to any of the above embodiments of the present invention; FIG. 7 is a cross-sectional view taken along line A--A; FIG. 8 is an enlarged cross-sectional view showing the details of the portion illustrated in FIG. 7; and FIG. 9 is a cross-sectional view which serves to illustrate the process of mounting the semiconductor device formed according to the preferred embodiment on a liquid crystal display device by pressure bonding. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows in cross section a part of a semiconductor device including connection electrodes formed according to a preferred embodiment of the present invention. As shown in FIG. 1, a semiconductor device 10 includes a semiconductor substrate 11, connection electrodes 12, a resin layer 13 and conductive particles 14. The connection electrodes 12, the resin layer 13 and the conductive particles 14 are formed on the semiconductor substrate 11 in advance. The connection electrodes 12 are each usually made of AlSi in which approximately 1% Si is added to Al. Since an extremely thin insulating oxide film of alumina or the like is formed over the surface of AlSi, resistance tends to easily increase at each connection. In order to decrease such connection resistance, as shown in FIG. 2, each AlSi electrode 12 may be coated with one or more metallic layers 15. The metallic layer 15 may be made of a metal selected from among Cr, Ti, W, Cu, Ni, Au, Ag, Pt, Pd and the like or an alloy of those metals. The coating may be carried out by depositing predetermined metal on the semiconductor device 10 by means of sputtering or electron-beam evaporation, forming a pattern by photolithography, and then selectively coating each electrode 12 with the metallic layer 15. Since Ni cannot be deposited directly on the electrode 12 made of AlSi by means of electroless plating, an alternative coating method may also be employed. One example method is carried out by selectively plating Pd on the electrode 12 and then substituting Ni for Pd by electroless plating to coat the electrode 12 with the metallic layer 15 of Ni. A surface protecting layer 16 is formed over the area of the semiconductor device 10 on which no electrode 12 is formed. The surface protecting layer 16 is made from a layer of, for example, SiN, SiO 2 or polymide. A resin layer 13 is formed over each of the electrodes 12 of the semiconductor device 10. The resin layer 13 is hardened by a method described later in a state wherein each conductive particle 14 is partially embedded in the resin layer 13. A part of the portion of the conductive particle 14 embedded in the resin layer 13 is held in contact with the surface of the electrode 12, while the other part protrudes from the resin layer 13. The resin layer 13 may be made of a resin material which can be softened even after being hardened, for example, a material selected from among synthetic resins such as acrylic resins, polyester resins, urethane resins, epoxy resins and silicone resins. Each of the conductive particles 14 is formed by an elastomeric particle 14a made of polymeric material and a coating layer 14b made of conductive material, which layer 14b covers the surface of the respective elastomeric particle 14a. The material for the elastomeric particles 14a may be selected from among synthetic resins such as polyimide resins, epoxy resins and acrylic resins or synthetic rubbers such as silicone rubber, urethane rubber and the like. The conductive material for the coating layer 14b may be selected from among metals such as Au, Ag, Pt, Cu, Ni, C, In, Sn, Pb and Pd or an alloy of these metals. Each coating layer 14b may be made as one layer or a combination of two layers or more. If each coating layer 14b is to be formed as a combination of two layers or more, as shown in FIG. 3, it is preferable to form a metallic layer 14b1 made of a metal exhibiting excellent adhesiveness with respect to the elastomeric particle 14a, for example, Ni, and then to coat the metallic layer 14b1 with a metal layer 14b2 of Au in order to prevent oxidization of the above metal. This layer coating may be effected by utilizing deposition such as sputtering or electron-beam deposition or electroless deposition. Alternatively, as shown in FIG. 4, the entire conductive particle 14 may be formed of a metal selected from among Au, Ag, Pt, Cu, Ni, C, In, Sn, Pb and Pd or an alloy of two or more of these metals. FIGS. 5a, 5b and 5c are cross-sectional views which serve to illustrate the process of forming connection electrodes of the semiconductor device 10 shown in FIG. 1. As shown in FIG. 5a, the electrodes 12 and the surface protecting layer 16 are formed on the semiconductor substrate 11 in advance. A coat of photosetting resin is applied to the surfaces of the electrodes 12 and the protecting layer 16 by, for example, spin coating or roll coating, thereby forming a resin layer 13 over the electrodes 12 and the layer 16. The resin layer 13 may be made of, for example, a material in which a photo-setting agent is mixed with a base material such as a thermoplastic resin of the acrylic or polyester type, a material in which a photoreactive radical is added to a base material, or a material in which a thermoplastic resin is mixed with a base material such as a photo-setting resin. As shown in FIG. 5b, the resin layer 13 formed over the substrate 11 is illuminated by ultraviolet rays 18 through a mask 17. The mask 17 is provided with blocking portions 17a for blocking the ultraviolet rays 18 and openings 17b through which the ultraviolet rays 18 can pass. The pattern of the electrodes 12 on the substrate 11 and that of the openings 17b in the mask 17 are formed such that they can be made coincident with each other. After the mask 17 and the resin layer 13 have been aligned in a superimposed state, illumination with the ultraviolet rays 18 is effected. In this manner, only the portion of the resin layer 13b which correspond to the pattern of the electrodes 12 is hardened, while the portion which is not exposed to the ultraviolet rays 18 is not hardened. Then, the resin layer 13 which has been selectively illuminated with the ultraviolet rays 18 is developed with a solvent. The solvent may be selected from among ketones such as acetone and methyl ethyl ketone or alcohols. In general, since the hardened resin does not easily dissolve in the solvent, the development is easy. More specifically, in the portion of the resin layer 13b which is hardened by illumination with the ultraviolet rays 18, cross-linking reactions are caused by the ultraviolet rays 18. The hardened resin layer 13b exhibits little or no solubility with respect to the solvent. In contrast, since such a reaction does not occur in the portion of the resin layer 13a which is not hardened because of no exposure to the ultraviolet rays 18, the nonhardened portion can be easily dissolved and removed with the solvent. It is therefore possible to form the resin layer 13b on only the pattern on the electrodes 12. Then, the substrate 11 is heated to approximately 50°-200° C., and the hardened resin layer 13b is again softened. In this state, as shown in FIG. 5c, the conductive particles 14 are scattered on and stuck to the resin layer 13b remaining on the pattern of the electrodes 12. Since the re-softened resin layer 13b has viscosity, the conductive particles 14 can adhere to them. In contrast, the conductive particles 14 are merely attracted to the portion from which the resin layer 13b is removed, for example, the surface protecting layer 16. Accordingly, unwanted conductive particles 14 which are attracted to the area other than the pattern of the electrodes 12 due to electrostatic force or the like, can be easily removed by means of an air blower, a brush or the like. In the preferred embodiment, this removing operation is done after the scattering process. However, in another embodiment, the removing operation by means of an air blower can be done during the scattering of the conductive particles 14. Each conductive particle 14, which has been disposed on the resin layer 13b of the electrodes 12 in the aforesaid manner, is partially embedded in the resin layer 13b in such a manner that a part of the portion of the conductive particle 14 embedded in the resin layer 13b is held in contact with the surface of the electrode 12, while the other part protrudes from the resin layer 13b. Alternatively, the semiconductor device 10 having the electrodes 12 on which the conductive particles 14 are disposed may be connected to another circuit substrate by pressure bonding in such a manner as to force the conductive particles 14 through the resin layer 13b to partially come into contact with the electrode 12 by the pressure applied to the semiconductor device 10 and the circuit substrate. When corresponding electrodes are to be connected to each other via the conductive particles 14, an adhesive may be charged and hardened between the corresponding electrodes. Thus, the electrical connections are sealed by resin and the reliability of connection is improved. FIG. 6 shows in cross section a liquid crystal display device 20 on which is mounted the semiconductor device 10 produced in the above-described manner. FIG. 7 is a cross section taken along line A--A of FIG. 6, and FIG. 8 is an enlarged diagram showing the details of the portion shown in FIG. 7. As shown in FIG. 6, an electrode 21 and a plurality of opposing electrodes 22 are formed on the substrates 23 and 24, respectively, and the electrode 21 and the opposing electrodes 22 are opposed to each other by an intervening sealing resin 25. A liquid crystal 26 is charged between a pair of substrates 23 and 24. The electrode 21 of the substrate 23 extend from the area occupied by the liquid crystal 26 into the right-hand side (as viewed in FIG. 6), and is connected via the conductive particles 14 to the semiconductor device 10 mounted for driving the liquid crystal display device 20. The connection between the substrate 23 and the semiconductor device 10 is sealed by the adhesive 27 as shown in FIGS. 7 and 8. In the semiconductor device 10, a diffused layer is formed on the semiconductor substrate 11 (FIG. 1) made of silicon, gallium arsenide or the like to constitute a multiplicity of transistors and diodes. Accordingly, the semiconductor device 10 has the function of driving the liquid crystal display device 20. The electrode 21 of the substrate 23 is made of, for example, a soda glass sheet. ITO (Indium Tin Oxide), ITO plated with Ni to reduce contact resistance, or the like is formed on the surface of the soda glass sheet. The thickness of the electrode 21 is usually approximately 50-200 mm. As shown in FIG. 9, the surface of the semiconductor device 10 on which projecting electrodes composed of the conductive particles 14 are formed, is positioned so as to oppose the surface of the substrate 23 on which the electrode 21 is formed. Then, the conductive particles 14 and the electrode 21 are aligned. The adhesive 27 is charged between the aligned substrates 11 and 23 and the conductive particles 14. The semiconductor device 10 is pressed against the substrate 23 via the conductive particles 14 and the adhesive 27 in the direction indicated by arrows 28 until the distance between the electrodes 12 and 21 reaches a predetermined gap l1 as shown in FIG. 8. In this pressed state, the adhesive 27 is hardened to mount the semiconductor device 10 on the substrate 23. The adhesive 27 may be selected from among various adhesives such as reaction-curing adhesives, anaerobic curing adhesives, thermosetting adhesives and photosetting adhesives. In the above embodiment, since the substrate 23 is made of glass which is a transparent material, it is particularly effective to use a photosetting adhesive for rapid bonding as the adhesive 27. Each of the embodiments has been explained with reference to the example in which the conductive particles 14 are disposed on the connection electrodes 12 on the semiconductor device 10. However, the present invention is not limited to the above semiconductor device and, for example, conductive particles may be disposed on the connection electrodes of other circuit substrates of various kinds for pressure bonding. Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.

A connection electrodes producing method has a step of forming resin layer which can be softened after hardened, on a circuit substrate on which an electrode pattern is formed. Then, only the resin layer material on the electrode pattern is cured and left. Thereafter, conductive particles are adhered to only the resin layer on the electrode pattern by softening the resin layer and by scattering the conductive particles on the circuit substrate with the softened resin layer.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a plasma display panel and, more particularly, to a plasma display panel that is adaptive for minimizing noise/vibration and heat generated therefrom. 2. Description of the Related Art Recently, various flat panel devices have been developed that reduce weight and bulk, which are drawbacks of the cathode ray tube (CRT). Such flat panel display devices include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) and an electro-luminescence display (ELD), etc. The PDP of these flat panel display devices allows an ultraviolet ray, generated upon discharge of an inactive mixed gas, such as He+Xe, Ne+Xe or He+Xe+Ne, etc., to radiate a phosphorous material to thereby display a picture. The PDP has been used for high-resolution television, monitors and as an internal or external advertising display because it has a rapid response speed and is suitable for displaying a large-area picture. FIG. 1A and FIG. 1B show the internal structure of the conventional plasma display panel. Referring to FIG. 1A and FIG. 1B , the conventional PDP includes a display panel 2 , a frame (or heatproof panel) 8 , and a printed circuit board 16 . The display panel 2 includes a front substrate 6 and a rear substrate 4 . The rear substrate 4 is coated with a phosphorous material (not shown). The front substrate 6 transmits light generated from the phosphorous material to thereby display a desired picture. The rear substrate 4 of the display panel 2 is adhered with a double-faced tape 12 having high heat conductivity, by which the display panel 2 is joined with the frame 8 . The double-faced tape 12 acts to transfer heat generated upon driving of the display panel 2 into the frame 8 . Since such a double-faced tape 12 has high density and hardness to facilitate a high heat-conductivity function, it rapidly transfers heat generated upon driving of the display panel 2 into the frame 8 . Accordingly, the frame 8 not only supports the display panel, but also discharges heat. The printed circuit board 16 is attached to the frame 8 to supply the display panel 2 with a desired driving signal. To this end, the printed circuit board 16 and the display panel 2 are connected to a flexible printed circuit (FPC) (not shown). Further, the printed circuit board 16 and the frame 8 are engaged with a plurality of screws 10 . To this end, the frame 8 includes a plurality of protrusions 14 into which the screws 10 can be inserted. As shown in FIG. 2 , such a conventional PDP is provided with a set case 20 to enclose the PDP when it is produced. The set case 20 includes a filter glass 18 and a back cover 17 . The filter glass 18 controls transmittivity of the light emitted from the display panel 2 , while the back cover 17 protects the PDP from external impact. In the conventional PDP, heat generated upon driving of the display panel 2 as well as vibration and resulting noise are transferred, via the double-faced tape 12 , to the frame 8 . In other words, the noise/vibration generated upon driving of the display panel 2 are caused, at least partly, by physical factors within the display panel 2 itself. More specifically, ions generated from the rear substrate 4 and the front substrate 6 are opposed with each other, having barrier ribs therebetween which, upon plasma discharge, are bombarded along with the front substrate 6 . In this case, when the height of the barrier ribs is not uniform, causing a stepped coverage between the barrier ribs and the front substrate 6 , vibration is generated between the stepped barrier ribs and the front substrate 6 by the collision force of the ions. Due to the vibration of the barrier ribs within the discharge cells and the front substrate 6 , noise/vibration is generated throughout the entire display panel 2 . As described above, heat generated upon driving of the display panel 2 is discharged, via the double-faced tape 12 , to the frame 8 , whereas noise/vibration generated upon driving of the display panel 2 superposes with noise/vibration generated from electronic components mounted onto the printed circuit board 16 . In other words, noise/vibration generated from the display panel 2 is easily propagated, via the double-faced, high-density tape 12 , into the frame 8 to superpose with noise/vibration generated from the printed circuit board 16 . As a result, rear noise/vibration of the PDP is greatly increased in comparison with noise/vibration generated from the printed circuit board 16 itself. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a plasma display panel that is adaptive for minimizing noise/vibration generated therefrom. A further object of the present invention is to provide a plasma display panel that is adaptive for minimizing heat generated therefrom. In order to achieve these and other objects of the invention, a plasma display panel according to an embodiment of the present invention includes a display panel for displaying a picture; and a porous pad provided at the display panel. Herein, the porous pad is made of a material that absorbs noise/vibration and conducts heat. The plasma display panel further includes a printed circuit board mounted with a plurality of integrated circuits for applying driving signals to the display panel; and a heatproof panel arranged between the porous pad and the printed circuit board. The plasma display panel further includes a double-faced tape having a heat-conducting function and provided between the display panel and the porous pad. The plasma display panel further includes a filter glass provided at the front side of the display panel to control transmittivity of light emitted from the display panel; and a back cover for covering the printed circuit board. The plasma display panel further includes a second porous pad provided between the printed circuit board and the back cover. Herein, the porous pad is formed from a mixture of a silicon material and a foam agent. Herein, the foam agent contains an urethane foam. The plasma display panel further includes an adhesive coated onto the porous pad. Herein, the adhesive is made from an acrylic material. Herein, the porous pad is formed from a mixture containing approximately 89% silicon, approximately 10% foam agent and approximately 1% adhesive. Herein, the second porous pad is made of a material that absorbs noise/vibration. A plasma display panel according to another aspect of the present invention includes a display panel for displaying a picture; a frame adjacent a rear surface of said display panel; a printed circuit board adjacent a rear surface of said frame and connected thereto by fastening elements; and a porous pad positioned between said display panel and said frame, said porous pad absorbing noise/vibration generated upon driving of said display panel to minimize noise/vibration transferred to said frame. Herein, said porous pad is made of a heat-conducting material that, in addition to absorbing noise/vibration, also enables said pad to transfer heat from said display panel to said frame. Herein, said porous pad is made of a mixture of silicon and urethane. Herein, said porous pad has an outer adhesive layer and is adhered to said display panel and to said frame by said layer. Herein, said porous pad is made of approximately 89% silicon, 10% foam agent, and 1% adhesive. The plasma display panel further includes an outer casing surrounding said plasma display panel, said outer casing having a back cover and a front cover, said back cover including a second porous pad adhered to an inner surface thereof adjacent said printed circuit board, said second porous pad absorbing noise/vibration generated as a result of said printed circuit board applying driving signals to said display panel. The plasma display panel further includes an outer casing surrounding said plasma display panel, said outer casing having a back cover and a front cover, said back cover including a second porous pad adhered to an inner surface thereof adjacent said printed circuit board, said second porous pad absorbing noise/vibration generated as a result of said printed circuit board applying driving signals to said display panel. Herein, said porous pad is made of a mixture of silicon and urethane that, in addition to absorbing noise/vibration, also enables said pad to transfer heat from said display panel to said frame. Herein, said porous pad has an outer layer of acrylic adhesive by which said pad is adhered to said display panel and to said frame, said porous pad being approximately 89% silicon, 10% foam agent, and 1% adhesive. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects of the invention will be apparent from the following detailed description of the embodiments of the present invention with reference to the accompanying drawings, in which: FIG. 1A and FIG. 1B illustrate an internal structure of a conventional plasma display panel; FIG. 2 shows the conventional display panel of FIG. 1B installed within a set case; FIG. 3A is an exploded perspective view representing an internal structure of a plasma display panel according to a first embodiment of the present invention; FIG. 3B is a section view representing the internal structure of a plasma display panel according to the first embodiment of the present invention; FIG. 4 is a section view of the porous pad shown in FIG. 3A and FIG. 3B ; FIG. 5 is a section view showing the plasma display panel of FIG. 3B according to the first embodiment of the present invention, as installed within a set case; FIG. 6 is a section view representing an internal structure of a plasma display panel according to a second embodiment of the present invention; and FIG. 7 is a section view representing an internal structure of a plasma display panel according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 3A and FIG. 3B , a plasma display panel (PDP) according to a first embodiment of the present invention includes a display panel 22 for displaying a picture, a frame (or heat-proof panel) 28 , a porous pad 32 for preventing noise/vibration generated from the display panel 22 from being transferred to the frame 28 ; and a printed circuit board 36 . The display panel 22 includes a front substrate 26 and a rear substrate 24 . The rear substrate 24 is coated with a phosphorous material (not shown). The front substrate 26 transmits light generated from the phosphorous material to thereby display a desired picture. The rear substrate 24 of the display panel 22 is adhered with a porous pad 32 , by which the display panel 22 is joined with the frame 28 . Since the porous pad 32 has a function of absorbing noise and vibration, it absorbs and shields against propagation of noise/vibration, generated upon driving of the display panel 22 , to the frame. Also, since the porous pad 32 has a heat conducting function, it transfers heat, generated upon driving of the display panel 22 , to the frame 28 . Herein, the noise/vibration generated upon driving of the display panel 22 are caused by physical factors within the display panel 22 . More specifically, ions generated from the rear substrate 24 and the front substrate 26 are opposed with each other, having barrier ribs therebetween which, upon plasma discharge, are bombarded along with the front substrate 26 . In this case, when the height of the barrier ribs is not uniform, causing a stepped coverage between the barrier ribs and the front substrate 26 , vibration is generated between the stepped barrier ribs and the front substrate 26 by the collision force of the ions. Due to the vibration of the barrier ribs within the discharge cells and the front substrate 26 , noise/vibration is generated throughout the entire display panel 22 . Accordingly, the porous pad 32 , formed from a porous type material having a low density and a low hardness, is provided for absorbing noise/vibration generated from the display panel 22 As shown in FIG. 4 , the porous pad 32 is made by mixing silicon 46 with a foam agent 48 to prepare a pad and then coating an adhesive 50 onto the front surface and the rear surface of the prepared pad. At this moment, the foam agent 48 contains urethane foam. Accordingly, porous materials are formed at the interior of the silicon 46 of the pad by the urethane foam included in the foam agent 48 . An acrylic material is used as the adhesive 50 coated on the front surface and the rear surface of the pad. In this case, the porous pad 32 contains approximately 89% silicon, approximately 10% foam agent 48 and approximately 1% adhesive. The porous material formed by the foam agent 48 contained in the porous pad 32 absorbs noise/vibration propagated from the display panel 22 . Further, heat generated upon driving of the display panel 22 is transferred, via the silicon 46 contained in the porous pad 32 , to the frame 28 to thereby discharge the heat generated from the display panel. Moreover, the porous pad 32 absorbs any external impact by its porous materials. The printed circuit board 36 is attached to the frame 28 to supply the display panel 22 with a desired driving signal. To this end, the printed circuit board 36 and the display panel 22 are connected to each other by a flexible printed circuit (FPC) (not shown). Further, the printed circuit board 36 and the frame 28 are engaged with a plurality of screws 30 . To this end, the frame 28 includes a plurality of protrusions 34 into which the screws 30 can be inserted. As shown in FIG. 5 , such a PDP according to the first embodiment of the present invention is provided with a set case 40 to enclose the PDP when it is produced. The set case 40 includes a filter glass 44 and a back cover 42 . The filter glass 44 controls the transmittivity of light emitted from the display panel 22 . The back cover 42 protects the PDP from external impact. In the PDP according to the first embodiment of the present invention, the porous pad 32 , attached between the display panel 22 and the frame 28 , can absorb noise/vibration generated upon driving of the display panel 22 to prevent the transfer of noise/vibration into the frame 28 , thereby minimizing the noise/vibration. Accordingly, noise/vibration at the rear surface of the PDP is limited to that generated by the printed circuit board 36 itself because the noise/vibration from the display panel 22 is damped by the porous pad 32 . Furthermore, the PDP according to the first embodiment of the present invention can discharge heat generated upon driving of the display panel 22 because such heat is transferred, via the porous pad 32 , to the frame 28 . Referring to FIG. 6 , a plasma display panel (PDP) according to a second embodiment of the present invention includes a display panel 52 for displaying a picture, a frame (or heat-proof panel) 58 , a heat-conductive double-faced tape 64 provided between the display panel 52 and the frame 58 , a porous pad 62 provided between the heat-conductive double-faced tape 64 and the frame 58 to prevent noise/vibration generated from the display panel 52 from being transferred to the frame 58 , and a printed circuit board 66 . The display panel 52 includes a front substrate and a rear substrate (not shown). The rear substrate is coated with a phosphorous material (not shown). The front substrate transmits light generated from the phosphorous material to thereby display a desired picture. The rear substrate of the display panel 52 is adhered with the heat-conductive double-faced tape 64 , by which the display panel 52 is joined with the frame 58 . The heat-conductive double-faced tape 64 , made of a material having high density and hardness to rapidly transfer heat, acts to transfer heat, generated upon driving of the display panel 52 , to the frame 58 . Accordingly, the frame 58 not only supports the display panel, but also discharges heat upon driving of the display panel 52 . The porous pad 62 joins the heat-conductive double-faced tape 64 with the frame 28 . Since the porous pad 62 has a function of absorbing noise and vibration, it absorbs and shields against propagation of noise/vibration, generated upon driving of the display panel 52 , via the heat-conductive double-faced tape 64 , to the frame 58 . Also, since the porous pad 62 has a heat conducting function, it transfers heat delivered through the heat-conductive double-faced tape 64 to the frame 58 . To this end, the porous pad 62 is formed from a porous type material having a low density and a low hardness. The porous pad 62 is made by mixing silicon 96 with a foam agent 98 to prepare a pad and then coating an adhesive 80 onto the front surface and the rear surface of the prepared pad. At this moment, the foam agent 98 contains urethane foam. Accordingly, porous materials are formed at the interior of the silicon 96 of the pad by the urethane foam included in the foam agent 98 . An acrylic material is used as the adhesive 80 coated on the front surface and the rear surface of the pad. In this case, the porous pad 62 contains approximately 89% silicon 96 , approximately 10% foam agent 98 and approximately 1% adhesive. The porous material formed by the foam agent 78 contained in the porous pad 62 absorbs noise/vibration propagated from the display panel 52 . Further, heat generated upon driving of the display panel 52 is transferred, via the silicon 96 contained in the porous pad 62 , to the frame 58 to thereby discharge the heat generated from the display panel 52 . Moreover, the porous pad 52 absorbs any external impact by its porous materials. The printed circuit board 66 is attached to the frame 58 to supply the display panel 52 with a desired driving signal. To this end, the printed circuit board 66 and the display panel 52 are connected to each other by a flexible printed circuit (FPC) (not shown). Further, the printed circuit board 66 and the frame 58 are engaged with a plurality of screws (not shown). To this end, the frame 58 includes a plurality of protrusions 54 into which the screws can be inserted. Such a PDP according to the second embodiment of the present invention is provided with a set case 70 to enclose the PDP when it is produced. The set case 70 includes a filter glass 56 and a back cover 68 . The filter glass 56 controls the transmittivity of light emitted from the display panel 52 . The back cover 68 protects the PDP from any external impact. In the PDP according to the second embodiment of the present invention, the porous pad 62 attached between the display panel 52 and the frame 58 can absorb noise/vibration generated upon driving of the display panel 52 to prevent the transfer of noise/vibration into the frame 58 , thereby minimizing the noise/vibration. Accordingly, noise/vibration at the rear side of the PDP is limited to that generated by the printed circuit board 66 itself because the noise/vibration from the display panel 52 is damped by the porous pad 62 . Furthermore, the PDP according to the second embodiment of the present invention can discharge heat generated upon driving of the display panel 52 because such heat is transferred, via the heat-conductive double-faced tape 64 and the porous pad 62 , to the frame 58 . Referring to FIG. 7 , a plasma display panel (PDP) according to a third embodiment of the present invention includes a display panel 72 for displaying a picture, a frame (or heat-proof panel) 78 , a first porous pad 82 for preventing noise/vibration generated from the display panel 72 from being transferred to the frame 78 , and a printed circuit board 76 . The display panel 72 includes a front substrate and a rear substrate (not shown). The rear substrate is coated with a phosphorous material (not shown). The front substrate transmits light generated from the phosphorous material to thereby display a desired picture. The rear substrate of the display panel 72 is adhered with the first porous pad 82 , by which the display panel 72 is joined with the frame 78 . Since the first porous pad 82 has a function of absorbing noise and vibration, it absorbs and shields against propagation of noise/vibration, generated upon driving of the display panel 72 , to the frame 78 . Also, since the first porous pad 82 has a heat conducting function, it transfers heat generated upon driving of the display panel 72 to the frame 78 . To this end, the first porous pad 82 is formed from a porous type material having a low density and a low hardness. The first porous pad 82 is made by mixing silicon 106 with a foam agent 108 to prepare a pad and then coating an adhesive 100 onto the front surface and the rear surface of the prepared pad. At this moment, the foam agent 108 contains urethane foam. Accordingly, porous materials are formed at the interior of the silicon 106 of the pad by the urethane foam included in the foam agent 108 . An acrylic material is used as the adhesive 100 coated on the front surface and the rear surface of the pad. In this case, the first porous pad 82 contains approximately 89% silicon, approximately 10% foam agent 108 and approximately 1% adhesive. The porous material formed by the foam agent 108 contained in the first porous pad 82 absorbs noise/vibration propagated from the display panel 72 . Further, heat generated upon driving of the display panel 72 is transferred, via the silicon 106 contained in the first porous pad 82 , to the frame 78 to thereby discharge the heat generated from the display panel 72 . Moreover, the first porous pad 82 absorbs any external impact by its porous materials. The printed circuit board 76 is attached to the frame 78 to supply the display panel 72 with a desired driving signal. To this end, the printed circuit board 76 and the display panel 72 are connected to each other by a flexible printed circuit (FPC) (not shown). Further, the printed circuit board 76 and the frame 78 are engaged with a plurality of screws (not shown). To this end, the frame 78 includes a plurality of protrusions 74 into which the screws can be inserted. Due to the driving of electronic elements mounted onto the printed circuit board 76 , noise/vibration is generated at the printed circuit board 76 . Such a PDP according to the third embodiment of the present invention is provided with a set case 90 to enclose the PDP when it is produced. The set case 90 includes a filter glass 94 and a back cover 92 . The filter glass 94 controls the transmittivity of light emitted from the display panel 72 . The back cover 92 protects the PDP from any external impact. Further, a second porous pad 86 for damping noise/vibration generated from the printed circuit board 76 is provided at the inner side of the back cover 92 opposed to the printed circuit board 76 . Since the second porous pad 86 has a function of absorbing noise/vibration, it is identical to the above-mentioned first porous pad 82 , absorbing noise/vibration generated from the printed circuit board 76 . In the PDP according to the third embodiment of the present invention, the first porous pad 82 attached between the display panel 72 and the frame 78 can absorb noise/vibration generated upon driving of the display panel 72 to prevent the transfer of noise/vibration into the frame 78 , thereby minimizing the noise/vibration. Furthermore, the second porous pad 86 , having the function of absorbing noise/vibration, absorbs noise/vibration generated as a result of the printed circuit board 76 applying driving signals to the display panel 72 . As described above, according to the present invention, the porous pad is provided between the display panel and the frame to thereby absorb and damp noise/vibration generated upon driving of the display panel. Accordingly, it becomes possible to minimize the generation of noise from the PDP. Although the present invention has been explained by the embodiments shown in the drawings described above, it should be understood to the ordinary skilled person in the art that the invention is not limited to the specific embodiments shown, but rather that various changes or modifications thereof are possible without departing from the spirit of the invention. Accordingly, the scope of the invention shall be determined only by the appended claims and their equivalents.

A plasma display panel adapted to minimize noise/vibration as well as a heat generated therefrom. In the plasma display panel, a display panel displays a picture while a porous pad is provided behind the display panel to prevent the transfer of noise/vibration to an associated heat proof panel. When the PDP is mounted within a case, a second porous pad can be provided on an inner surface of the case opposite the display panel and adjacent to an associated printed circuit board for additional noise/vibration damping.

BACKGROUND OF THE INVENTION This invention relates generally to machines used in making ophthalmic lenses and more particularly concerns machines used to fine and polish ophthalmic lenses. In presently known fining/polishing machines which simultaneously fine or polish two lenses, the motion of the block adapters is achieved by the use of separate swing frames for each adapter and separate drive mechanisms for each swing frame. To accommodate the multiple frames and drive components, these machines require a relatively large foot print. They are difficult to maintain in calibration. They are configured for material specific cycles and reconfiguration requires time and pressure adjustments to be made manually by the operator. It is, therefore, an object of this invention to provide a fining/polishing machine suitable for simultaneously fining or polishing two lenses. Another object of this invention is to provide a fining/polishing machine having its calibrated components mounted on a single rigid frame. It is also an object of this invention to provide a fining/polishing machine having two block adapter assemblies mounted on a single swing frame. A further object of this invention is to provide a fining/polishing machine capable of simultaneously fining or polishing two lenses by use of a single drive motor. Yet another object of this invention is to provide a fining/polishing machine with computerized controls enabling an operator to automatically set machine operating parameters by selecting the material of the lens to be fined/polished. It is also an object of this invention to provide a fining/polishing machine having a computerized process enabling the operator to automatically set cycle times and fining/polishing pressures by selection of the material of the lenses to be fined/polished. A further object of this invention is to provide a fining/polishing machine which is smaller and more economical than known machines performing the same functions. SUMMARY OF THE INVENTION In accordance with the invention, a machine for fining/polishing ophthalmic lenses is provided having a horizontal plate and a vertical plate rigidly fixed to and extending upwardly from a midportion of the horizontal plate. A first eccentric shaft is journalled on the horizontal plate for orbiting a first tool about a first vertical axis on one side of the vertical plate and a second eccentric shaft is journalled on the horizontal plate for orbiting a second tool about a second vertical axis on the same side of the vertical plate. The first and second vertical axes are in a plane parallel to the vertical plate. A swing frame is pivotally mounted on the other side of the vertical plate and has a horizontal shaft parallel to the vertical plate. A first shaft orthogonal to the horizontal shaft is journalled for see-saw motion about the horizontal shaft, for rotational motion about its own longitudinal axis and for sliding motion along the horizontal shaft. The first shaft extends through an aperture in the vertical plate with its longitudinal axis intersecting the first vertical axis. A block adapter on the end of the shaft holds a first lens in vertical alignment above the first tool. A second shaft orthogonal to the horizontal shaft is journalled for see-saw motion about the horizontal shaft for rotational motion about its own longitudinal axis and for sliding motion along the horizontal shaft. The second shaft extends through another aperture in the vertical plate with its longitudinal axis intersecting the second vertical axis. A block adapter on the end of the shaft holds a second lens in vertical alignment above the second tool. A first linkage reciprocally moves the horizontal shaft in parallel relationship to the vertical plate and a second linkage simultaneously reciprocally moves the first and second orthogonal shafts in orthogonal relationship to the vertical plate. The horizontal and orthogonal shaft linkages have a timing ratio therebetween such that the first and second block adapters travel in a horizontal figure eight pattern aligned with the first and second orthogonal shafts and reciprocating in a direction parallel to the vertical plate. The lens holding ends of the first and second orthogonal shafts are adapted for independent adjustment of their lengths to permit horizontal realignment of the block adapters. The lens holding ends of the first and second orthogonal shafts are also adapted for independent adjustment to permit vertical realignment of the block adapters. This facilitates easy adjustment and synchronization of the machine. Preferably, the timing ratio provides slightly more than two reciprocations of the horizontal shaft for each reciprocation of the orthogonal shafts. It is also preferred that the eccentric axes of the first and second tools rotate 180 degrees out of phase and that the first and second orthogonal shafts slide in the same direction. First and second air cylinders connected to opposite ends of the first and second orthogonal shafts as the lens holding means cause the first and second orthogonal shafts to see-saw to maintain a desired pressure between the tools and the lenses. A microprocessor has data stored therein representative of appropriate times of operation of the machine and pressures between the tools and lenses for a plurality of lens materials and fining/polishing operations. The microprocessor automatically sets and controls the time of operation of the machine and the pressure between the tools and lenses in response to input to the microprocessor of the materials of the lens to be fined/polished and the selected fining/polishing operation. The horizontal and vertical plate fixed reference relationship avoids calibration problems experienced with previous machines. The use of a single swing frame with a single drive linkage and separately alignable block adapters allows for a smaller machine footprint than previous double linkage machines, reducing machine width by more than 25 percent. Computer control results in faster and more accurate operation than the operator controlled time and pressure parameters for each material as in previous machines, saving approximately thirty seconds in a 120 to 240 second process. BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which: FIG. 1 is a schematic diagram of a preferred embodiment of the fining/polishing machine; FIG. 2 is a perspective view of the machine of FIG. 1 fully assembled; FIG. 3 is a front perspective view of a preferred embodiment of the upper portion of the machine of FIG. 2 with the top cover removed; FIG. 4 is a rear perspective view of a preferred embodiment of the upper portion of the machine of FIG. 2 with the top cover removed; FIG. 5 is a perspective assembly view of a preferred embodiment of the base plate assembly of the machine of FIG. 2; FIG. 6 is a perspective assembly view of a preferred embodiment of the motor mounting assembly of the machine of FIG. 2; FIG. 7 is a perspective assembly view of preferred embodiments of the speed reducer assembly and spoke spindle assembly of the machine of FIG. 2; FIG. 8 is a perspective assembly view of a preferred embodiment of the swing frame assembly of the machine of FIG. 2; FIG. 9 is a perspective assembly view of the swing frame assembly of FIG. 2 positioned for mounting on the base plate assembly of FIG. 2; FIG. 10 is a perspective assembly view of a preferred embodiment of the rocker housing assemblies of the machine of FIG. 2; FIG. 11 is a perspective assembly view illustrating a preferred embodiment of the swing linkage of the machine of FIG. 2; FIG. 12 is a perspective assembly view of a preferred embodiment of the spindle assembly of the machine of FIG. 2; FIG. 13 is a top plan view of a preferred embodiment of the swing disk of the machine of FIG. 2; FIG. 14 is a perspective assembly view of a preferred embodiment of the slide linkage of the machine of FIG. 2; FIG. 15 is a partial perspective view illustrating the assembled slide linkage of FIG. 14; FIG. 16 is a perspective assembly view of a preferred embodiment of the lap apron assemblies of the machine of FIG. 2; FIG. 17 is a perspective view with parts broken away of the assembled lap apron assemblies of FIG. 16; FIG. 18 is a front perspective view of preferred embodiment of the block adapter and rocker arm assembly of the machine of FIG. 2; FIG. 19 is a bottom perspective view of the block adapter and rocker arm assembly of FIG. 18; FIG. 20 is a perspective assembly view of a preferred embodiment of the valve assembly of the machine of FIG. 2; FIG. 21 is a perspective view of the assembled valve assembly of FIG. 20; FIG. 22 is a perspective assembly view of a preferred embodiment of the control panel assembly of the machine of FIG. 2; FIG. 23 is a perspective view of the assembled control panel assembly of FIG. 22; FIG. 24 is a flow diagram illustrating the mode and diagnostic options available to the machine operator; FIG. 25 is a flow diagram illustrating the lens material options available to the machine operator; and FIG. 26 is a flow diagram illustrating the emergency stop and machine malfunction options available to the machine operator. While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. DETAILED DESCRIPTION Turning first to FIG. 1, a preferred embodiment of the fining/polishing machine is diagrammatically illustrated. Right and left lap apron assemblies 30 and 130 are used to fine/polish lenses (not shown) chucked to right and left block adapter assemblies 210 and 310. The lap apron assemblies 30 and 130 are orbited on right and left lap eccentric axes 31 and 131 which intersect right and left lap rotational axes 33 and 133, the rotational axes 33 and 133 being vertically aligned on the machine frame F in a common plane. The block adapter assemblies 210 and 310 are centered on right and left block adapter central axes 211 and 311 which are vertically aligned with the rotational axes 33 and 133 of the lap apron assemblies 30 and 130. The block adapter assemblies 210 and 310 are driven in horizontal figure eight patterns taken in relation to the front and rear directions 213 and 313 of the machine, the figure eight patterns being reciprocated in lateral directions 215 and 315 with respect to the machine. The reciprocating horizontal figure eight patterns of motion are accomplished by the use of right and left rocker housing assemblies 230 and 330 which are mounted on a swing frame 400 assembly on a common horizontal lateral axis 401 parallel to the plane of the rotational axes 33 and 133 of the lap apron assemblies 30 and 130. The swing frame 401 is pivotally mounted on the machine frame F so that the horizontal axis 401 can be arcuately reciprocated in relation to the plane of the lap apron assembly rotational axes 33 and 133. A swing disk 403 is rotationally driven about a swing eccentric rotational axis 405 and a swing linkage 407 is connected between the swing frame horizontal axis 401 and an eccentric point on the swing disk 403 to cause the axis 401 to reciprocate arcuately over a small distance to produce a substantially horizontal motion in the front and rear directions 213 and 313. A slide disk 409 is rotatively driven about a slide eccentric rotational axis 411 and is eccentrically connected by a slide linkage 413 to the rocker housing assemblies 230 and 330, causing the rocker housing assemblies 230 and 330 to reciprocate laterally along the swing frame horizontal axis 401 to produce substantially horizontal movement in the lateral direction 213 and 315. The rotational axes 405 and 411 of the swing and slide disks 403 and 409 are vertically fixed in relation to the machine frame F. The combination of motions imparted to the rocker housing assemblies 230 and 330 by the swing disk 403 and the slide disk 409 together with a timing ratio between the disks 403 and 409 which is not equal to unity results in the horizontal reciprocating figure eight patterns of motion hereinbefore discussed. The orbiting of the lap apron assemblies 30 and 130 and the rotation of the disks 403 and 409 are achieved by the use of a single drive motor with appropriate timing belts and pulleys to establish the desired timing ratio, as will hereinafter be explained. To provide suitable fining/polishing force to the lenses, the block adapter assemblies 210 and 310 are slidably engaged to right and left block adapter cylinders 201 and 301 which are fixed to the machine frame F. The cylinders 201 and 301 have shafts 203 and 303 which are adapted to slidably receive shafts of their respective rocker housing assemblies 230 and 330 on the opposite side of the rocker housing assemblies 230 and 330 from the block adapter assemblies 210 and 310. Thus, upward forces 205 and 305 exerted on the rocker housing assemblies 230 and 330 by the cylinders 201 and 301 result in downward forces 207 and 307 being exerted on the block adapter assemblies 210 and 310 to maintain the necessary forces to properly fine/polish the lenses. Looking now at FIGS. 2, 3 and 4, a preferred embodiment of the fining/polishing machine is shown. The machine includes a floor mounted cabinet having side panels 501 and 503, a lower front door 505 with a built-in rinse basin 507 on its upper end and a top cover 509 including a tray 511 seated on top of the cover 509. The lower rear portion of the machine is closed by a back panel 513. The front cover 509 is provided with an access opening 515 extending across and above the rinse basin 507. Above and to the left of the access door are the main power switch 517 and the emergency stop switch 519 and on the right side of the machine above the access opening 515 are a keyboard 521 and LCD display 523. The access opening 515 opens into the fining/polishing enclosure or slurry bowl 525, giving the operator access to the right and left apron assemblies 30 and 130 and the right and left block adapter assemblies 210 and 310. The slurry bowl 525 is seated on a base plate 531 which extends horizontally substantially from the front to the rear of the machine. The slurry bowl 525 has a bottom drain (not shown) which vents through an opening in the base plate 531 to a reservoir in the lower portion of the cabinet. A slurry source and pump a (not shown) are also contained in the cabinet. A vertically aligned swing frame mounting plate 533 is rigidly fixed to and extends laterally substantially across the width of the base plate 531. The back of the slurry bowl 525 abuts the front of the mounting plate 533. The base plate 531 and mounting plate 533 are the major structural components of the machine frame F. As can best be seen in FIG. 4, the swing frame 400 is mounted on the rear face of the swing frame mounting plate 533. The rocker housing assemblies 230 and 330 are pivoted on the swing frame assembly 400 and the right and left air cylinders 201 and 301 are mounted on a motor mount fixed to the base plate 531 and connected to the rear portions of the rocker housing assembly 230 and 330. A back plate 535 supports the pneumatic and electrical systems 537 and 539 for the machine. The main components of the machine frame F are shown in greater detail in FIG. 5. The swing frame mounting plate 533 is fastened to the base plate 531 by screws 541 and reinforced in this position by swing frame support plates 543 and 545 fastened to the mounting plate 533 and to the base plate 531 by screws 547 and 549. A mounting bracket 551 to which the swing frame assembly 400 will be connected is fastened to the upper portion of the mounting plate 533 by screws 553. A motor mount 555 is fastened to the rear bottom face of the base plate 531 by screws 557. Apertures 561 are provided in the front portion of the base plate 531 to accommodate the lap apron assemblies 30 and 130 and apertures 565 and 567 are provided in the rear of the base plate 531 to accommodate the air cylinders 201 and 301. Another aperture 569 in approximately the center rear portion of the base plate 531 accommodates the timing belt pulley 457 of the machine drive motor 451. An aperture 570 through the front central portion of the base plate 531 accommodates connection of the slurry bowl 525 to the slurry source and reservoir in the cabinet below. Finally, apertures 571 and 573 are provided in the mounting plate 533 to accommodate the rocker housing assemblies 230 and 330. As shown in FIG. 6, the machine main drive motor 451 is connected to the motor mount 555 by a bracket 455 with screws, lock washers and washers 453. The motor 451 is preferably a 3/4 horsepower 120/240 volt A.C. 50/60 cycle motor. The timing belt pulley 457 is fixed to the motor shaft 459 by a set screw 461 and is oriented in relation to the shaft 459 by a shaft key 463. A belt tensioner 465 is fastened to the bottom of the base plate 531 at the timing belt pulley aperture 569 by use of screws and washers 467, one screw extending through a slot 469 which allows the opposite end of the tensioner 465 to be reoriented by rotation of the tensioner 465 about the other screw 467. An idler bearing assembly 471 is mounted to the lower face of the tensioner 465 by a screw 473 and a stand off and washer assembly 475. Thus, the position of the idler bearing assembly 471 can be adjusted by repositioning the slot 469 of the tensioner 465 in relation to the screw 467 extending through the slot 469. The pulley 457 is connected by a belt (not shown) to the lap apron assemblies 30 and 130 below the base plate 531. As shown in FIG. 7, a stroke spindle bracket 477 is secured to the base plate 531 by screws and washers 479. A stroke spindle assembly 481 is secured to the top of the bracket 477 by screws and washers 483. A speed reducer 485 is fastened to the front of the bracket 479 by use of screws and washers 487 and the primary shaft 489 of the speed reducer 485 is engaged with a second timing pulley 458. The idler bearing assembly 471 engages the belt (not shown) between the first and second pulleys 457 and 458. A third timing belt pulley 491 is secured to a secondary shaft 493 of the speed reducer 485 by a set screw 495, the pulley 491 being oriented by a shaft key 497. The slide disk 409 is fastened to the pulley 491 by screws 415. The swing disk 403 is mounted on a stroke spindle assembly 401 which is rotatively coupled a fourth timing belt pulley 417 to the speed reducer secondary shaft timing belt pulley 491 by a timing belt 499. The swing frame assembly 400 is shown in greater detail in FIG. 8. It consists of an upper member 419 with axially aligned bronze flange bushings 421 and 423. Right and left lower members 425 and 427, respectively, are secured to the bottom portion of the upper member 419 by use of screws 429. The lower members 425 and 427 have axially aligned apertures 431 through their lower portions. Looking at FIG. 9, an upper swing frame shaft 433 extending through the bronze flanges 421 and 423 connects the upper member 419 of the swing frame assembly 400 to the bracket 555 on the swing frame mounting plate 533. Set screws 435 lock the upper swing frame shaft 433 in the bracket 555 and the swing frame assembly 400 is free to rotate on the upper swing frame shaft 433 about the swing frame axis 437 as shown in FIG. 1. The right and left rocker housing assemblies 230 and 330 are aligned in the right and left lower members 425 and 427 of the swing frame assembly 400 and a lower swing frame shaft 439 extends through the apertures 431 in the lower swing frame members 425 and 427 and through transverse cylinders 255 and 355 on the rocker housing assemblies 230 and 330 as shown in FIG. 10. Set screws 441 lock the lower swing frame shaft 439 in the swing frame assembly 400 and the rocker housing assemblies 230 and 330 are free to rotate on the lower swing frame shaft 439 about the swing frame horizontal axis 401 shown in FIG. 1. The left and right rocker housing assemblies 230 and 330 are illustrated in greater detail in FIG. 10. A rocker shaft 231 or 331 has a limit collar 233 or 333 fixed to its rearward portion by brass soft shoes 235 or 335 held in place by set screws 237 or 337. A rocker housing 241 or 341 slides over the shaft 231 or 331. A ball bearing 243 or 343 is held in the rearward end of the housing 241 or 341 by the limit collar 233 or 333. The forward end of the housing 241 or 341 holds a second ball bearing 245 or 345 through which the shaft 231 or 331 extends. A second limit collar 247 or 347 secures the position of the ball bearing 245 or 345 and the collar 247 or 347 is fixed to the forward end of the shaft 231 or 331 by soft shoes 249 held in place by set screws 251. The housing 241 or 341 is aligned on the shaft 231 or 331 by a spring pin 253 or 353 and a transverse cylindrical section 255 or 355 with bronze bushings 257 or 357 and 259 or 359 in either end. A shown in FIG. 9, the lower swing frame shaft 439 extends through the bushings 257, 259, 357 and 359. Thus, the transverse cylindrical sections 255 and 355 of the housing 241 and 341 are aligned for rotation about the swing frame horizontal axis 401 as shown in FIG. 1. As can best be seen in FIG. 4, the shafts 203 and 303 of the block adapter cylinders 201 and 301 are connected to the rear ends of the rocker housing assembly shafts 231 and 331 to rotate the rocker housing assemblies 230 and 330 about the swing frame horizontal axis 401 and exert the desired force on the block adapter assemblies 210 and 310. The free ends of the shafts 203 and 303 extend into the slurry bowl 525. Looking now at FIGS. 11, 12 and 13, the swing linkage 407 connecting the swing disk 403 to the swing frame assembly 400 is shown in greater detail. The linkage 407 consists of a screw 443 with bearing rods 445 threaded onto each end and fixed in place by jam nuts 447. The bearing rods 445 are rotatively connected to the swing disk 403 and to a block on the swing frame assembly 400 by screws 449. The spindle timing belt pulley 417, also shown in FIG. 7, is fixed to the end of the spindle shaft 575 by a set screw 577. The shaft 575 is mounted for rotation in the spindle housing 579 on ball bearings 581 and 583, the lower ball bearing 581 being held in place by a retaining ring 585. As can best be seen in FIG. 13, the swing disk 403 has two eccentric apertures 587 and 589 for receiving the screw 449. One eccentric aperture 587 is spaced at a greater distance 591 from the perimeter of the disk than the other aperture 589 which is spaced at a smaller distance 593. The eccentric aperture 587 more distant from the perimeter of the disk 403 is used for fining while the other eccentric aperture 589 is used for polishing. It has been found that a fining distance 591 in a range of 0.156 inches is satisfactory while a polishing distance 593 in a range of 0.094 inches results in satisfactory displacements of the swing frame lower shaft 439 of 0.25 inches or 0.187 inches, respectively. FIGS. 11, 14 and 15 illustrate the slide linkage 413 used to connect the slide disk 409 to the rocker housing assemblies 230 and 330. A pair of screws 217 and 317 have bearing rods 219 and 319 and 221 and 321 threaded on their ends and adjustably locked in place by jam nuts 223 and 323 and 225 and 325. A screw 595 extends through one bearing rod 221 and 321 of each of the screws 217 and 317. The screw 595 engages the linkage 413 to an aperture 597 in the slide disk 409, as can best be seen in FIG. 11. The other bearing rods 219 and 319 are connected by screws 227 and 327 to the right and left rocker housing assemblies 230 and 330. A bearing spacer 599 adjusts for the stacked relationship of the bearing rods 221 and 321 on the center screws 595. The rocker housing assemblies 230 and 330 move simultaneously in the same lateral direction on the lower swing frame shaft 439. The right and left lap apron assemblies 30 and 130 are illustrated in greater detail in FIGS. 16 and 17. The assemblies 30 and 130 have eccentric cam shafts 35 or 135 with the eccentric axes 31 or 131 being displaced from the rotational axes 33 or 133 by an angle 37 or 137 which is preferably approximately four degrees and provides a horizontal displacement of approximately 1/4 inch. An orbital cam housing 39 or 139 has needle roller bearings 41 or 141 and 43 or 143 mounted in its upper and lower ends, respectively, in which the eccentric cam shaft 35 or 135 is rotatively mounted. A slurry bowl gasket 45 or 145 is seated on an annular flange 47 or 147 around the orbital cam housing 39 or 139. The lower bearing 43 or 143 is held in place by a bearing guide 49 or 149 and a retaining ring 51 or 151. A straight zerk 53 or 153 is connected to the lower end of the eccentric cam shaft 35 or 135 for admitting lubricant into the shaft 35 or 135 for the needle bearings 39 and 41 or 139 and 141. The orbital cam housing 39 or 139 is inserted into its respective aperture 561 or 563 in the base plate 531 with the top face of the flange 47 or 147 against the lower face of the base plate 531. A diaphragm mounting ring 55 or 155 slides over the upper portion of the orbital cam housing 39 and clamps the lap apron assembly 30 or 130 to the slurry bowl 527 with the gasket 45 or 145 providing the necessary seal. An apron shield 57 or 157 seated on an upper rubber flange 61 or 161 of the diaphragm mounting ring 55 or 155 is secured in place by a baffle ring 59 or 159 by screws 63 or 163. A double row ball bearing 65 or 165 mounted in the upper portion of the apron shield 57 or 157 rotatively holds the upper portion 67 and 167 of the eccentric shaft 35 or 135. The lap adapter 69 or 169 is secured to the top of the apron shield 57 or 157 by screws 71 or 171. The lap tool (not shown) will be located on the upper face of the lap adapter 69 or 169. A lap clamp lever 73 or 173 is pivotally connected to the lap adapter 69 or 169 by a lever pin 75 or 175 and an air cylinder assembly 77 or 177 is secured to the free end of the lap clamp lever 73 or 173 by screws 79 or 179. The lever 73 or 173 is provided with an aperture 81 or 181 and the air cylinder shaft (not shown) extends through the aperture 81 or 181 against a lap clamp shoe 83 or 183 mounted on the apron shield 57 or 157. Thus, with a lap tool (not shown) mounted on the lap adapter 69 or 169, the air cylinder assembly 77 or 177 can be operated to pivot the lap clamp lever 73 or 173 about the pivot pin 75 or 175 so that the clamping end 85 or 185 will secure the lap (not shown) in position on the lap adapter 69 or 169. As the eccentric shaft 35 or 135 rotates, the rubber flange 61 or 161 permits the lap adapter 69 or 169 to wobble without rotation. The right and left block adapter assemblies 210 and 310 are illustrated in FIGS. 18 and 19. The assembly 210 or 310 includes a housing 271 or 371 with a profile disk 273 or 373 centered in its bottom face for engagement with the blocked lens (not shown). The shaft 275 or 375 of the block adapter assembly 210 or 310 extends vertically upwardly from the block adapter assembly 210 or 310 on its central axis 271 or 371. The upper end 277 or 377 of the shaft 275 or 375 is mounted in an aperture 279 or 379 in the end of a long portion of a substantially J-shaped rocker arm 281 or 381. The end of the aperture 279 or 379 has a slot 283 or 383 extending to the outer wall of the rocker arm 281 or 381 with a screw 285 or 385 extending through the slotted portion to permit tightening or loosening of the aperture 279 or 379 on the shaft upper end 277 or 377. This permits adjustment of the height and rotational orientation of the block adapter assembly 210 or 310 in the rocker arm 281 or 381. The short leg of the J-shaped rocker arm 281 or 381 has a horizontally aligned aperture 287 or 387 through it with a slot 289 or 389 extending from the aperture 287 or 387 to the outer wall of this portion of the rocker arm 281 or 381. A screw 291 or 391 extending through this slotted portion permits loosening and tightening of the horizontal aperture 287 or 387. As can best be seen in FIG. 2, the aperture 287 or 387 in the short leg of the rocker arm 281 or 381 receives the front end of the rocker housing assembly shaft 231 or 331. Thus, the alignment of the vertical axis 211 or 311 of the block adapter assembly 210 or 310 can be adjusted in relation to the rotational axes 33 or 133 of the lap apron assembly 30 or 130 by loosening the horizontal aperture screws 291 or 391, sliding the rocker arm 281 or 381 to its desired position and retightening the screws 291 or 391. The valve assembly of the pneumatic system illustrated in FIG. 3 is shown in greater detail in FIGS. 20 and 21. A valve manifold 601 has its outlet port sealed with a plug 603. Four three-way solenoid valves 605, 607, 609 and 611 having air outlet ports 606, 608, 610 and 612 are mounted on the manifold 601. A bushing 613 and fitting 615 are connected to the air inlet port of the manifold 601. Two of the solenoid valve air outlet ports 606 and 608 are connected to opposite sides of one of the rocker assembly cylinders 201 and the air outlet ports 610 and 612 of the remaining solenoid valves 609 and 611 are connected to opposite sides of the other rocker assembly cylinder 301. Thus the valve assembly controls the downward force of the block adapter assemblies 210 and 310. The control panel assembly is illustrated in FIGS. 22 and 23. The display PC board 621 is mounted to the back of a keyboard backing plate 619 by screws 623. PC board standoffs 625 position the LCD display 523 as shown in FIG. 2 within a viewing aperture 627 in the keyboard backing plate 619. An SBC control card 629 is fastened to the keyboard backing plate 619 by use of screws 631 threaded into longer standoffs 633 which are secured to the keyboard backing plate 619 by set screws 635. The SBC control card 629 connects to a male strip header 637 mounted on the back of the PC board 621 and includes an EPROM section 639 which stores the machine operating program and a non-volatile RAM section 640 which stores the pressure, time, cycle and other data needed to serve the needs of the user. An LED diode 641, preferably green, is mounted to SBC control card 629 by a spacer 643 and extends through an aperture 645 in the keyboard backing plate 619. A special key pad 521, also shown in FIG. 2, is mounted on the front face of the keypad backing plate 619 and is connected by a cable 649 to the SBC control card 629. Turning to FIG. 24, the MODE and Diagnostics menus are illustrated. The operator will first "turn power switch on" 660. If, within five seconds of the machine being turned on, the operator presses [adjust] key at software version screen 661, setup options MATL/MODE/DIAG 665, 681 and 697 are presented, one of which may be selected by cursor. If the operator selects the MODE 665 option, the operator can then sequentially select "English/Francais/Deutche/Espanol" 667, "factory defaults <press start>" 669, "reversing time" 671, dual air time PSI" 673, "slurry shut off" 674, pressure units 675, "grease spindle reset time" 677 and "cycle/time" 679. "Factory default <press start>" 669 establishes the time and pressure parameters and other variables to which the machine will return on shut off. "Reversing time" 671 allows switching of the rotational direction of the drive motor 451. "Dual air time PSI" 673 permits the operator to select two different pressures to be applied to the same lenses during a single cycle. "Cycle time" 679 indicates the accumulated number of cycles and hours a machine has been in operation. If the operator selects the diagnostics DIAG 681 option, the operator can then sequentially select "axis calibration" 682, "center pattern press <start>" 683, "keypad test" 684, "display test" 685, "inputs" 687, "pressure/set" 689, "forward or reverse motor" 691, "slurry" 693 or "clamp" 694 for diagnostic evaluations. In any of these options, the operator can "change selection" 695. Turning to FIG. 25, the Material Setup menu is illustrated. If the operator selects the "MATL" 697 option, the operator then can select by cursor from the "POLISHER/ONE STEP/TWO STEP FINER" modes 700, 710 or 720. If the "polisher" 700 mode is selected, then the operator may select by cursor from five materials options including, as shown, "plastic" 701, "high index" 703, "poly" 705, "other" 707 or "glass" 709. If the "one step finer" 710 mode is selected, the operator then can select between "plastic" 711, "high index" 713, "poly" 715, "other" 717 or "glass" 719. If the "two step finer" 720 mode is selected, the operator then can select "plastic" 721 and 731, "high index" 723 and 733, "poly" 725 and 735, "other" 727 and 737 or "glass" 729 and 739. In various options presented in the Material Setup menu, the operator can select the time and pressure at each appropriate option, the pressure level being variable in 1 psi increments from 10 to 40 psi and the time being variable in 5 second increments up to 9 minutes, 55 seconds. If the operator does not "press [adjust]" 661 in the required time, the machine proceeds to a Run Mode as shown in FIG. 26. After the operator "turns power switch on" 660, "the software version screen displays briefly, then goes directly to the material screen last selected" 661. The fining/polishing modes 700, 710 and 720 as discussed in relation to FIG. 25 will then be presented for selection by the operator and the machine will operate accordingly. After the selected use time, at the end of a cycle the machine will display a "grease spindle" 662 notice. This notice will be redisplayed at the end of every cycle until the operator will "press [start] to reset timer or [stop] to abort the message" 663. If, during the operation of the machine, the emergency stop 519 is pressed, operation of the machine will be immediately terminated. When the emergency stop 519 is manually released, the machine will return to the software version screen. If the machine is turned off at the end of a cycle by use of the main power switch 517, the machine will return to the factory default parameters in the last selected mode of operation. In operating the machine, the operator mounts the appropriate lap tool (not shown) on the lap apron input assemblies 30 and 130 and chucks the lenses to be fined/polished to the block adapter assemblies 210 and 310. The operator selects the appropriate machine and material types for the lenses to be fined/polished in accordance with the diagram of FIG. 25. This will set the preselected time and pressure parameters for the operation of the machine from the programmed parameters stored in the machine. These parameters can be reprogrammed by the operator if necessary. This can be done by use of the MODE 665 option shown in FIG. 24. With the machine ready to operate, pressing the start key on the keyboard 521 will cause the rocker arm cylinders 201 and 301 to apply the selected force to the block adapter assemblies 210 and 310. The lap clamps 85 and 185 are then closed by their air cylinders 77 and 177 and the slurry pump is started. The motor 451 is then engaged to begin rotation of the swing disk 403, the slide disk 409, and the shafts 35 and 135 of the lap apron assemblies 30 and 130. The rotation of the swing disk 403 and the slide disk 409 causes the block adapter assemblies 210 and 310 to move in figure eight patterns while the non-unity timing ratio causes the figure eight patterns to be laterally reciprocated. Looking at FIG. 7, it is preferred that the slide pulley 491 be a 43 tooth pulley while the swing pulley 417 is a 21 tooth pulley, so that the swing pulley 417 will have rotated one tooth more than two revolutions for each revolution of the slide pulley 491. The orbital motion of the lap apron assemblies 130 and 330 and reciprocating figure eight motion patterns of the block adapter assemblies 210 and 310 are imposed upon the lenses at the predetermined pressure exerted by the air cylinders 201 and 301 at the other end of the shafts 231 and 331 of the rocker housing assemblies 230 and 330. The surface to surface positioning of the lap (not shown) against the lenses (not shown) is facilitated by the rotation of the shafts 231 and 331 of the rocker housing assemblies 230 and 330 within the housings 230 and 330 which permits the block adapter assemblies 210 and 310 to float the lens contours on the laps. Because of the use of a single swing frame 400 mounted to the vertical plate 533 which is in turn fixed to the base plate 531 supporting the lap apron assemblies 30 and 130, machine calibration problems are greatly reduced in comparison to previously known machines. Once the linkages 407 and 413 have been adjusted to length, fine tuning can be accomplished by the operator through the machine access door 515 by adjusting the level of the block adapter assemblies 210 and 310 by repositioning the block adapter assembly shafts 271 and 371 in the bracket arms 261 and 361 and by changing the horizontal positioning of the bracket arms 261 and 361 on the rocker shafts 231 and 331. Thus, it is apparent that there has been provided, in accordance with the invention, a fining/polishing machine that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art and in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit of the appended claims.

A machine for fining/polishing ophthalmic lenses has a horizontal and vertical plates rigidly fixed in an inverted T. Eccentric shafts journalled 180 degrees out of phase on the horizontal plate orbit tools on one side of the vertical plate. A swing frame pivotally mounted on the other side of the vertical plate has a horizontal shaft parallel to the vertical plate. Shafts orthogonal to the horizontal shaft are journalled for see-saw motion about the horizontal shaft, for rotational motion about their own longitudinal axes and for sliding motion along the horizontal shaft. Block adapters on the orthogonal shafts hold lenses in vertical alignment above the tools. Separate linkages reciprocate the horizontal shaft in parallel relationship to the vertical plate and the orthogonal shafts in orthogonal relationship to the vertical plate. The shaft linkages have a timing ratio such that the block adapters travel in laterally reciprocating horizontal figure eight patterns. The orthogonal shafts are adapted for independent adjustment to permit horizontal and vertical realignment of the block adapters. Air cylinders see-saw the orthogonal shafts to maintain a desired pressure between the tools and lenses. A microprocessor storing data representative of appropriate times of operation of the machine and pressures between the tools and lenses for a plurality of lens materials and fining/polishing operations automatically sets and controls the time of operation of the machine and the pressure between the tools and lenses in response to input in directing the material of the lens to be fined/polished and the selected fining/polishing operation.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to scanning probe microscopes represented by a scanning tunneling microscope (STM), atomic force microscope (AFM), etc., and more specifically, to a scanning probe microscope, such as a scanning tunneling spectroscopic microscope or scanning tunneling potentiometric microscopes for measuring the electrical properties of the surface of a sample. 2. Description of the Related Art One of scanning probe microscopes (SPMs) is proposed in U.S. Pat. No. Re. 33,387 entitled "Atomic Force Microscope and Method for Imaging Surfaces with Atomic Resolution." The SPMs have high resolutions on the atomic size level with respect to the vertical and horizontal directions despite their simple construction, and are represented by a scanning tunneling microscope (STM), atomic force microscope (AFM), etc. Since the AFM was devised by G. Binnig et al., the inventors of the STM, (see "Physical Review Letters" vol. 56, p 930, 1986), it has been expected as novel surface configuration observing means for insulating materials and further investigated. The AFM has a probe, which is supported by means of a flexible cantilever. As the probe is brought close to the surface of a sample, a Van der Waals force first acts between the distal end of the probe and the sample surface. When the distance between the probe and the sample surface approaches the atomic distance, a repulsion force based on the Pauli exclusion principle then acts. The cantilever is displaced depending on the magnitude of an atomic force the distal end of the probe receives. Thus, an image of indentations of the sample surface can be obtained by scanning the sample surface with the probe and detecting the displacement of the cantilever between various points. The STM moves the probe for scanning while keeping a tunneling current flowing between the probe and the sample constant by applying a bias voltage between the two, and obtains a servo signal for controlling the distance between the probe and the sample. The servo signal contains STM information, that is, reflects indentation information for the sample surface. Thus, an STM image with resolutions on the atomic size level can be obtained by plotting the STM information corresponding to the coordinates of measuring points. The tunneling current reflects the distance between the probe and the sample, local state of electrons on the sample, and local potential of the sample. Accordingly, a normal STM image contains indentation information indicative of the microscopic roughness of the sample surface and information for the local potential distribution on the sample surface. Recently, there have been developed scanning tunneling spectroscopy (STS) and scanning tunneling potentiometry (STP). In the STS, the indentation information and electronic property information for the sample surface are separated from the tunneling current, whereby information for the state of electrons on the surface are extracted. In the STP, the information for the potential distribution on the sample surface is extracted from the tunneling current. Current imaging tunneling spectroscopy (CITS) is a representative of digital STS. In the CITS, the local density distribution of electrons on the sample surface is measured in accordance with the dependence of the tunneling current on the bias voltage. The CITS is based on the fact that the differential conductance is proportional to the local electron density in the case where the tunneling gap (distance between sample and probe) and barrier height are fixed without regard to the location. Thus, in the CITS, local current and voltage values are obtained as the probe is moved for scanning, they are stored in advance for each measuring point, and the differential conductance is obtained later by numerical computation. The STS and STP measurements are carried out by using a probe for STM measurement on the assumption that the distance between the probe and the sample is fixed. The probe is relatively moved for XY-scanning over the surface of the sample in parallel relation throughout a measuring region of the surface. In the scanning operation, the probe is temporarily stopped at each of a large number of measuring points that are previously suitably arranged on a scanning line, and the electrical properties of the sample surface at each measuring point are measured by means of the probe. The measurement of the electrical properties at each measuring point is made in a manner such that the distance between the probe and the sample is fixed at a predetermined value. More specifically, the distance between the probe and the sample is adjusted and fixed to a length equivalent to a predetermined value of the tunneling current flowing through the probe. Then, the electrical properties of the sample surface at each measuring point is determined by examining the value of the tunneling current flowing through the probe while changing the voltage applied between the probe and the sample. While a piezoelectric scanner is used to control the distance between the probe and the sample, it tends to undergo creeping or drift. For these reasons, the distance between the probe and the sample cannot be kept fixed during the STS or STP measurement. SUMMARY OF THE INVENTION An object of the present invention is to provide a scanning microscope, such as a scanning tunneling spectroscopic microscope or scanning tunneling potentiometric microscope, for measuring the electrical properties of the surface of a sample with the distance between the probe and the sample fixed. Another object of the invention is to provide a cantilever chip adapted for use in the scanning probe microscope described above. Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the descriptions or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. FIG. 1 schematically shows a scanning tunneling spectroscopic microscope according to a preferred embodiment of the present invention; FIG. 2 is a timing chart for the measuring operation of the spectroscopic microscope shown in FIG. 1; FIG. 3 shows a scanning tunneling spectroscopic microscope according to a modification of the apparatus of FIG. 1; FIG. 4 schematically shows a scanning tunneling spectroscopic microscope according to another preferred embodiment of the invention; FIG. 5 is a perspective view of a cantilever chip particularly applicable to the apparatus of FIG. 1; FIG. 6 is a bottom view of the cantilever chip of FIG. 5; FIG. 7 is a sectional view of the cantilever chip taken along line VII--VII of FIG. 6; FIGS. 8A to 8D show a manufacturing process for the cantilever chip shown in FIGS. 5 to 7; FIG. 9 is a perspective view of another cantilever chip particularly applicable to the apparatus of FIG. 1; FIG. 10 is a bottom view of the cantilever chip of FIG. 9; FIG. 11 is a perspective view of still another cantilever chip particularly applicable to the apparatus of FIG. 1; FIG. 12 is a bottom view of the cantilever chip of FIG. 11; FIG. 13 is a sectional view of the cantilever chip taken along line XIII--XIII of FIG. 12; FIGS. 14A to 14E show a manufacturing process for the cantilever chip shown in FIGS. 11 to 13; FIG. 15 is a bottom view of a further cantilever chip particularly applicable to the apparatus of FIG. 1; FIG. 16 is a sectional view of the cantilever chip taken along line XVI--XVI of FIG. 15; FIG. 17 is a perspective view of a cantilever chip with a displacement detecting function particularly applicable to the apparatus of FIG. 1 in place of a cantilever and a displacement sensor therefor; and FIG. 18 is a bottom view showing the cantilever chip of FIG. 17 along with peripheral circuits. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows a scanning tunneling spectroscopic microscope according to a preferred embodiment of the present invention. As shown in FIG. 1, a metallic probe 301 is held by a holder 300. A cantilever 302 is one-sidedly supported on the holder 300 so that a probe 303 on its distal end is situated below the metallic probe 301. The cantilever 302 is preferably formed of a thin plate with a material that is as light in weight and high in elasticity as possible so that a substantial displacement can be obtained for an infinitesimal force, such as an atomic force. A Z-displacement sensor 304 optically detects a Z-direction displacement of the cantilever 302, and outputs an electrical signal (cantilever displacement signal ΔZ) corresponding to the displacement. A piezoelectric device 305 supports the holder 300 for movement in the Z-direction. A sample 308 is located under the metallic probe 301 and the cantilever 302, and can be moved for position adjustment and XY-scanning in the X- and Y-directions by means of an XY-stage 310 that carries the sample thereon. A DAC (digital-to-analog converter) 309 outputs a tunneling bias voltage V T , which is supplied to an electrode (not shown) attached to the sample 308. An I/V converter 311 converts a tunneling current flowing through the metallic probe 301, and outputs it as a tunneling current signal I T . An ADC (analog-to-digital converter) 312 subjects the tunneling current signal I T to A/D conversion when it is supplied with an STS sampling signal. A numerical processing unit 313 processes tunneling current data, the output of the ADC 312, and computes spectroscopic data. An ADC 604 subjects the cantilever displacement signal ΔZ from the Z-displacement sensor 304 to A/D conversion, and outputs cantilever displacement data as conversion data. A memory circuit 605 temporarily stores the cantilever displacement data delivered from the ADC 604. A DAC 601 subjects the cantilever displacement data stored in the memory circuit 605 to D/A conversion, and outputs a signal that is indicative of the displacement state of the cantilever 302 established when a desired distance is kept between the metallic probe 301 and the sample 308, that is, a servo reference signal S 2 as a target value of the cantilever displacement signal ΔZ. A DAC 602 outputs a signal that is indicative of the tunneling current signal I T obtained when the desired distance is kept between the metallic probe 301 and the sample 308, that is, a servo reference signal S 1 as a target value of the tunneling current signal I T . A switch circuit 600 supplies a servo circuit 306 selectively with the tunneling current signal I T from the I/V converter 311 or the cantilever displacement signal ΔZ from the Z-displacement sensor 304. A switch circuit 603 supplies the servo circuit 306 selectively with the servo reference signal S 2 from the DAC 601 or the servo reference signal S 1 from the DAC 602. The servo circuit 306 subjects the piezoelectric device 305 to feedback control such that the tunneling current signal I T supplied thereto through the switch circuit 600 is coincident with the servo reference signal S 1 supplied through the switch circuit 603 or that the cantilever displacement signal ΔZ supplied through the circuit 600 is coincident with the servo reference signal S 2 supplied through the circuit 603. An STS measurement is made by means of the scanning tunneling spectroscopic microscope in the following manner. First, a region of the sample 308 to be measured is aligned with an XY-scanning range of the XY-stage 310. The measurement is carried out successively for all of a large number of measuring points on a predetermined scanning line. The following is a description of measuring operation at one of the measuring points. The sample 308 is moved by the XY-stage 310 so that the measuring point is situated right under the metallic probe 301. In response to a servo switching signal, the switch circuits 600 and 603 are set at B, whereupon the tunneling current signal I T and the servo reference signal S 1 delivered from the I/V converter 311 and the DAC 602, respectively, are selected. The DAC 309 outputs a constant bias voltage V T , which is applied to the sample 308. The tunneling current flowing through the metallic probe 301 is converted into the tunneling current signal I T by the I/V converter 311, and is supplied to the servo circuit 306 through the switch circuit 600. At the same time, the DAC 602 outputs the servo reference signal S 1 , the target value of the signal I T , which is supplied to the servo circuit 306 through the switch circuit 603. The servo circuit 306 regulates the voltage applied to the piezoelectric device 305 so that the tunneling current signal I T delivered from the I/V converter 311 is coincident with the servo reference signal S 1 . Thereupon, the holder 300 is brought close to the sample 308 so that the signal I T is equivalent to the target value. In this manner, the distance between the metallic probe 301 and the sample 308 is adjusted to the desired one. When the desired distance is kept between the metallic probe 301 and the sample 308, the cantilever 302 is displaced by the contact between the probe 303 and the sample 308. The Z-displacement sensor 304 detects the displacement of the cantilever 302, and delivers the cantilever displacement signal ΔZ, indicative of the cantilever displacement, to the ADC 604. The ADC 604 subjects the displacement signal ΔZ to A/D conversion, and delivers the cantilever displacement data, as its conversion data, to the memory circuit 605. The circuit 605 temporarily stores the cantilever displacement data, and delivers the data to the DAC 601. The DAC 601 subjects the cantilever displacement data delivered from the memory circuit 605 to D/A conversion, and delivers its conversion signal to the switch circuit 603. The conversion signal delivered from the DAC 601 represents the displacement of the cantilever 302 made when the desired distance is kept between the metallic probe 301 and the sample 308, and forms the servo reference signal S 2 as the target value for servo control based on the cantilever displacement signal ΔZ, which will be described below. Then, in response to the servo switching signal, the switch circuits 600 and 603 are set at A, whereupon the cantilever displacement signal ΔZ and the servo reference signal S 2 delivered from the Z-displacement sensor 304 and the DAC 601, respectively, are selected. As a result, the signal ΔZ from the sensor 304 and the signal S 2 from the DAC 601 are supplied to the servo circuit 306. The circuit 306 controls the voltage applied to the piezoelectric device 305 so that the cantilever displacement signal ΔZ delivered from the Z-displacement sensor 304 is always coincident with the serve reference signal S 2 . This control is continued at least during subsequent tunneling current sampling, and the desired distance between the metallic probe 301 and the sample 308 is maintained as long as the control is continued. Subsequently, the DAC 309 outputs the bias voltage V T that varies at a fixed gradient, and this voltage is applied to the sample 308. As this is done, the ADC 312 samples the tunneling current signal I T delivered from the I/V converter 311 in accordance with the STS sampling signal supplied thereto, converts the sampled signal into the tunneling current data, and delivers it to the numerical processing unit 313. The processing unit 313 obtains the spectroscopic data by processing the tunneling current data supplied thereto. FIG. 2 is a timing chart for the measuring operation described above. By time t 1 , the metallic probe 301 and the sample 308 are relatively moved for scanning, and the probe 301 is located on the measuring point. The switches 600 and 603 are shifted to B at time t 1 . The distance between the metallic probe 301 and the sample 308 is adjusted to the desired value by time t 2 . At time t 2 , the switches 600 and 603 are shifted to A, and control of the distance between the probe 301 and the sample 308 based on the displacement of the cantilever 302 is started. This control is continued until time t 5 . The bias voltage V T is varied during the period between times t 2 and t 5 . During the period between times t 3 and t 4 in which the bias voltage V T decreases at a fixed gradient, the STS sampling signal is supplied, and the tunneling current signal is sampled. The bias voltage V T is restored to a fixed value at time t 5 , whereupon the STS measurement at this measuring point ends. At time t 5 , the control of the distance between the metallic probe 301 and the sample 308, based on the displacement of the cantilever 302, is suspended, the probe 301 is kept apart from the sample 308, and the probe 301 and the sample 308 are relatively moved for scanning. The probe 301 is located on the next measuring point by time t 6 . The desired distance between the metallic probe 301 and the sample 308 is settled depending on the tunneling current flowing through the probe 301, and is kept constant by means of an AFM sensor (cantilever 302 and Z-displacement sensor 304). Accordingly, this arrangement is effective even in the case where the accurate relative positions of the metallic probe 301 and the probe 303 on the cantilever 302 in the Z-direction are indistinct. FIG. 3 shows a scanning tunneling spectroscopic microscope according to a modification of the present embodiment. Like reference numerals are used to designate like members in FIGS. 1 and 3, and a detailed description of those members is omitted. A sample stage 400 is attached to the XY-stage 310, and a dummy sample 401 is placed on the stage 400. The cantilever 302 is displaced by the contact between the probe 303 on its distal end and the dummy sample 401 on the sample stage 400, not the sample 308 for STS measurement. Except for those details, the apparatus according to this modification is arranged in quite the same manner as the one shown in FIG. 1, and the measurement is carried out in like manner. FIG. 4 schematically shows an arrangement of a scanning tunneling spectroscopic microscope according to another preferred embodiment of the present invention. Like reference numerals are used to designate like members in FIGS. 1 and 4, and a detailed description of those members is omitted. A sample stage 400 is attached to an XY-stage 310, and a dummy sample 401, formed of an electrical conductor, is placed on the stage 400. A DAC 502 outputs a constant tunneling bias voltage V T2 , which is supplied to an electrode (not shown) attached to the dummy sample 401. Both of metallic probes 301 and 501 are held by means of a holder 500. The probes 301 and 501 are located over a sample 308 to be measured and the dummy sample 401, respectively. An I/V converter 503 converts a tunneling current flowing through the metallic probe 501 by applying the tunneling bias voltage V T2 to the dummy sample 401, and outputs it as a tunneling current signal I T2 . A servo circuit 504 subjects a piezoelectric device 305 to feedback control such that the tunneling current signal I T2 , the output of the I/V converter 503, has a desired value, that is, the distance between the metallic probe 301 and the sample 308 is a desired one. A DAC 505 supplies the servo circuit 504 with a servo reference signal that indicates a target value of the tunneling current signal I T2 , the output of the I/V converter 503. An STS measurement is made by means of the scanning tunneling spectroscopic microscope in the following manner. First, a region of the sample 308 to be measured is aligned with an XY-scanning range of the XY-stage 310. The measurement is carried out successively for all of a large number of measuring points on a predetermined scanning line. The following is a description of measuring operation at one of the measuring points. First, the sample 308 is moved by the XY-stage 310 so that the measuring point is situated right under the metallic probe 301. The DAC 502 outputs the constant tunneling bias voltage V T2 , which is applied to the dummy sample 401. The tunneling current flowing through the metallic probe 501 is converted into the tunneling current signal I T2 by the I/V converter 503, and is supplied to the servo circuit 504. Then, the DAC 505 outputs the servo reference signal that indicates the predetermined target value of the tunneling current signal I T2 , which is applied to the input of the servo circuit 504. The circuit 504 regulates the voltage applied to the piezoelectric device 305 so that the tunneling current signal I T2 is coincident with the servo reference signal. Thereupon, the distance between the metallic probe 301 and the sample 308 is adjusted to the desired one. This control is continued at least during subsequent tunneling current sampling, and the desired distance between the metallic probe 301 and the sample 308 is maintained as long as the control is continued. Subsequently, a DAC 309 outputs a bias voltage V T that varies at a fixed gradient, and this voltage is applied to the sample 308. As this is done, an ADC 312 samples a tunneling current signal I T1 delivered from an I/V converter 311 in accordance with an STS sampling signal supplied thereto, converts the sampled signal into tunneling current data, and delivers it to a numerical processing unit 313. The processing unit 313 obtains spectroscopic data by processing the tunneling current data supplied thereto. Since the desired distance between the metallic probe 301 and the sample 308 is settled by means of an STM sensor (probe 501, I/V converter 503, and DAC 502), this arrangement is effective only in the case where the accurate relative positions of the metallic probes 301 and 501 are evident. Although the AFM or STM sensor is used to detect the distance between the metallic probe 301 and the sample 308 according to the embodiments described above, it may be replaced with some other sensor, such as a capacity sensor. Although the present invention is applied to the scanning tunneling spectroscopic microscope (STS) according to the foregoing embodiments, it may be also applied to scanning tunneling potentiometry (STP). Technology for the STP is described, for example, in U.S. Pat. No. 5,185,572 entitled "Scanning Tunneling Potentio-Spectroscopic Microscope and Data Detecting Method", which discloses an apparatus capable of STM, STS, and STP measurements. The description of this technology is incorporated herein. The following is a description of a cantilever chip applicable to the apparatuses according to the foregoing embodiments, especially the apparatus shown in FIG. 1. FIGS. 5 to 7 show a preferred example of the cantilever chip. As shown in FIGS. 5 and 6, the cantilever chip includes two cantilevers 1102 and 1104, which extend side by side from an end of a glass support section 1106. These two cantilevers 1102 and 1104 are formed of a silicon nitride film each, and have probes 1122 and 1124 on their respective free ends. The opposite surfaces of each cantilever are coated individually with gold films 1212 and 1214 (see FIG. 8D). The two cantilevers 1102 and 1104 are different in size, having lengths of 200 μm and 100 μm, respectively, for example. As shown in FIG. 6, the cantilevers 1102 and 1104 are separated from each other by a groove 1116 that is formed in the support section 1106. As shown in FIG. 7, therefore, the gold film 1214 formed on the probe side is divided between three gold films 1214a, 1214b and 1214c on a silicon nitride film 1114, in the groove 1116, and on a silicon nitride film 1112, respectively. Thus, the cantilevers 1102 and 1104 and therefore, the probes 1122 and 1124, are insulated electrically from one another. FIGS. 8A to 8D show manufacturing process for the cantilever chip shown in FIGS. 5 to 7. A silicon wafer 1202 is prepared, and it is formed with a hole 1204 for the formation of a probe by, for example, dry etching (FIG. 8A). Then, a silicon nitride film (0.4 to 1 μm thick) is formed by CVD on that surface of the wafer 1202 which has the hole 1204 therein, and the formed film is patterned by photolithography and dry etching (FIG. 8B). The patterned silicon nitride film 1208 has a shape corresponding to the cantilevers 1102 and 1104 shown in FIG. 6, and that portion of the film 1208 which corresponds to the L-shaped groove 1116 is removed. A Pyrex block 1210, which is worked in conformity with the pattern shape, is anodically bonded to the patterned silicon nitride film 1208 (FIG. 8C). The resulting structure is etched in a 40% aqueous solution of KOH, and dust and silicon oxide films adhering to the cantilevers are then removed by means of hydrofluoric acid. As this is done, an L-shaped portion of the glass support section 1106 on which the silicon nitride film 1208 is removed is etched, whereupon the groove 1116 shown in FIGS. 5 to 7 is formed. Finally, the gold films 1212 and 1214 are formed individually on the opposite surfaces of each cantilever (FIG. 8D). In order to enhance the adhesion of the films 1212 and 1214 to the cantilevers, chromium and gold may, for example, be deposited on the cantilevers before the gold films are formed. The cantilever chip of silicon nitride and Pyrex shown in FIGS. 5 to 7 is manufactured in the process described above. The shorter cantilever 1104 of the cantilever chip is used for the STS or STP measurement, and the longer cantilever 1102 for AFM sensor operation. More specifically, an electrode is connected to the gold film 1214a on the silicon nitride film 1114, a bias voltage is applied between the probe 1124 on the cantilever 1104 and the sample surface, and the electrical properties of the sample surface are detected by means of the probe 1124. The cantilever chip is supported obliquely. While the shorter cantilever 1104 is being used to detect the electrical properties of the sample surface, therefore, the probe 1122 on the longer cantilever 1102 is naturally in contact with the sample surface, so that the cantilever 1102 is displaced. This displacement is optically detected by means of reflected light from laser light applied to the gold film 1212 on the back of the cantilever 1102, and the vertical position of the cantilever chip with respect to the sample is controlled so that the displacement is constant. By this control, as mentioned before, the distance between the distal end of the probe 1124 and the sample surface is kept constant while the tunneling current for the STS or STP measurement is being sampled. Since the probes 1122 and 1124 are isolated electrically from each other by the groove 1116, the bias voltage applied to the probe 1124 can never influence the probe 1122 that is engaged in the AFM sensor operation. In contrast with this, an electrical signal received from the sample surface by the probe 1122 can never be involved in an electrical signal detected by means of the probe 1124, that is, the tunneling current for the STS or STP measurement. Thus, the cantilever chip is divided between the cantilever that has the probe for detecting the local electrical properties of the sample surface and the cantilever for keeping the distance between the probe and the sample surface constant. Accordingly, the distance between the probe and the sample surface can be set more accurately, so that the local electrical properties of the sample surface can be detected with higher accuracy. Moreover, the cantilever chip is designed so that the longer cantilever with a smaller spring constant is used for the AFM sensor operation to control the distance between the probe and the sample surface, and the shorter cantilever with a larger spring constant is used to detect the electrical properties of the sample surface. Thus, the distance between the probe and the sample surface can be controlled with high sensitivity without damaging the sample surface. Further, the cantilever chip can be easily manufactured with reliability by slightly changing the cantilever configuration of silicon nitride films manufactured by a conventional cantilever manufacturing method. Besides, the cantilever chip includes an electrical conductor for the detection of the electrical properties. Since this conductor is formed of a gold coating that cannot be easily oxidized, it can detect the electrical properties with higher accuracy. If the gold film of the cantilever for the AFM sensor operation is provided with an electrode such that the potential of the probe on the cantilever is equal to that of the sample, furthermore, an electrostatic force produced between the sample and the probe is canceled. Thus, the distance between the probe and the sample surface can be set more accurately, and the local electrical properties of the sample surface can be detected with accuracy. Although the cantilevers of this cantilever chip are triangular in shape, they may alternatively be rectangular. Also, the cantilever chip may be designed so that the longer cantilever for the AFM sensor operation and the shorter cantilever for the detection of the electrical properties are rectangular and triangular, respectively. Moreover, the two cantilevers may be arranged so that the one for the distance control is narrower and has a smaller spring constant (higher softness), and the other for the detection of the electrical properties is wider and has a larger spring constant (higher hardness). FIGS. 9 and 10 show another cantilever chip adapted for use in the apparatuses according to the foregoing embodiments, especially the apparatus shown in FIG. 1. This cantilever chip is manufactured substantially according to the manufacturing process for the foregoing cantilever chip. In this cantilever chip, as shown in FIGS. 9 and 10, a shorter cantilever 1404 is located in a hollow portion of a longer cantilever 1402. Probes 1412 and 1414 formed individually on the two cantilevers are insulated electrically from each other by two L-shaped grooves 1406 and 1408. Preferably, the longer cantilever 1402 is used for the AFM sensor operation to control the distance between the probe 1414 on the shorter cantilever 1404 and the sample, while the probe 1414 is used to detect the electrical properties of the sample surface. Since the shorter cantilever 1404 is located in the longer cantilever 1402, the probes 1412 and 1414 for the distance control and the detection of the electrical properties are situated nearer to each other than in the structure (cantilever chip shown in FIGS. 5 to 7) that includes the cantilevers arranged in parallel with each other. Thus, the distance between the probe 1414 and the sample can be controlled more accurately. Preferably, moreover, a straight line that connects the probes 1412 and 1414 is coincident with a longitudinal axis that passes through the respective centers of the cantilevers 1402 and 1404. This arrangement allows the probes 1412 and 1414 to be situated further closer to each other. Preferably, furthermore, the distance between the probes 1412 and 1414 is restricted to hundreds of micrometers or less. According to this cantilever chip, as compared with the foregoing one, therefore, the probes 1412 and 1414 can be situated nearer to each other, so that the distance between the probe and the sample surface can be set more accurately, and the electrical properties can be detected with accuracy. FIGS. 11 to 13 show still another cantilever chip adapted for use in the apparatuses according to the foregoing embodiments, especially the apparatus shown in FIG. 1. This cantilever chip includes silicon plates 1512 and 1514 that have cantilevers 1502 and 1504, respectively. The plates 1512 and 1514 are fixed to a silicon support section 1506 by means of a silicon oxide film 1521. The cantilever 1502 is relatively long and has a probe 1522 on its free end. The cantilever 1504 is relatively short and has a probe 1524 on its free end. Each of the silicon plates 1512 and 1514 has an electrically conductive layer 1530 formed on its probeside electrode surface. The plates 1512 and 1514 are divided by an L-shaped groove, so that the probe 1522 and 1524 are insulated electrically from each other. The silicon plate 1514 that has the cantilever 1504 is formed extending to that portion (not shown) of the support section opposite to the cantilever. FIGS. 14A to 14D show manufacturing process for the cantilever chip shown in FIGS. 11 to 13. First, a so-called silicon-on-insulator (SOI) substrate is prepared as a starting substrate by first forming the intermediate silicon oxide film 1521 on one surface of a silicon substrate 1620 with a plane bearing of (100) and then sticking a silicon substrate 1622 as an active layer with the same plane bearing of (100) to the film 1521 (FIG. 14A). A probe 1624 is first formed on the active layer 1622 by a method combining photolithography and dry or wet etching (FIG. 14B). Thereafter, an active layer 1626 having the probe 1624 thereon is patterned by photolithography and etching (FIG. 14C). A patterned active layer 1628 includes the cantilevers 1502 and 1504 shown in FIG. 12. Then, the electrode surface of the patterned active layer 1628 is injected with boron (B) or the like by ion implantation, whereupon the electrically conductive layer 1530 is formed (FIG. 14D). Thereafter, a mask is formed on the whole area of the conductive layer 1530 except the region corresponding to the L-shaped groove shown in FIG. 12, and the groove is formed by etching the conductive layer 1530, active layer 1628, and silicon oxide film 1521. Subsequently, the support section 1506 is formed by subjecting the silicon substrate 1620 to wet anisotropic etching from the back side. Finally, the silicon oxide films around the cantilevers and dust adhering to the cantilevers during the process are removed by means of an aqueous solution of hydrofluoric acid or the like (FIG. 14E). The silicon cantilever chip is manufactured according to the process described above. The shorter cantilever 1504 of the cantilever chip is used for the STS or STP measurement, and the longer cantilever 1502 for the AFM sensor operation. More specifically, an electrode is connected to the conductive layer 1530 on the electrode surface of the silicon plate 1514, a bias voltage is applied between the probe 1524 on the cantilever 1504 and the sample surface, and the electrical properties of the sample surface are detected by means of the probe 1524. Since the cantilever chip is supported obliquely, the probe 1522 is naturally in contact with the sample surface, so that the longer cantilever 1502 is displaced. This displacement is optically detected by, for example, optical means, and the cantilever chip is vertically moved with respect to the sample so that the displacement is constant. By this control, the distance between the distal end of the probe 1524 and the sample surface is kept constant while the tunneling current for the STS or STP measurement is being sampled. Since the probe 1522 for the AFM sensor operation and the probe 1524 for the detection of the electrical properties are insulated electrically from each other, the bias voltage applied to the probe 1524 can never influence the probe 1522 that is engaged in the AFM sensor operation, and an electrical signal received from the sample surface by the probe 1522 can never be involved in the electrical properties detected by means of the probe 1524. Thus, the cantilever chip is divided between the cantilever that has the probe for detecting the local electrical properties of the sample surface and the cantilever for keeping the distance between the probe and the sample surface constant. Accordingly, the distance between the probe and the sample surface can be set more accurately, so that the local electrical properties of the sample surface can be detected with higher accuracy. Moreover, the cantilever chip is designed so that the longer cantilever with a smaller spring constant is used for the AFM sensor operation to control the distance between the probe and the sample surface, and the shorter cantilever with a larger spring constant is used to detect the electrical properties of the sample surface. Thus, the distance between the probe and the sample surface can be controlled with high sensitivity without damaging the sample surface. Since the conductive layer of the cantilever chip is formed by injection ions into silicon, moreover, the radius of curvature of the distal end of the probe cannot become larger than during the formation of the probe. Thus, more local electrical properties can be detected, and the distance between the probe and the sample surface can be set more accurately. If the conductive layer of the cantilever for the AFM sensor operation is provided with an electrode such that the potential of the probe on the cantilever is equal to that of the sample, furthermore, an electrostatic force produced between the sample and the probe is canceled. Thus, the distance between the probe and the sample surface can be set more accurately, and the local electrical properties of the sample surface can be detected with accuracy. In this cantilever chip, no reflective film is formed on that surface of each cantilever opposite to the probe. Alternatively, however, a reflective film of metal or the like may be formed by coating. The silicon plates on the support section, having the cantilevers and conductive layer, like those of the aforementioned cantilever chip, may be shaped in the manner shown in FIG. 10. In the aforesaid process, moreover, the ion injection for the formation of the conductive layer is carried out after the patterning for the cantilever configuration. Alternatively, the patterning for the cantilever configuration may be effected after the ion injection. Further, the process for manufacturing the cantilever chip is not limited to the ones shown in FIGS. 14A to 14E. FIGS. 15 and 16 show a further cantilever chip adapted for use in the apparatuses according to the foregoing embodiments, especially the apparatus shown in FIG. 1. This cantilever chip is manufactured substantially according to the manufacturing process for the directly foregoing cantilever chip (FIGS. 11 to 13). More specifically, the cantilever chip of this modification is manufactured in the same manner as the foregoing one except that a resist is formed by photolithography on a part of the active layer 1628 corresponding to the silicon plate 1512, including the longer cantilever 1502, before ion injection, and that boron ions or the like are injected with use of the formed resist as a mask. As seen from FIG. 16, therefore, this cantilever chip is designed so that the silicon plate 1514 including the shorter cantilever 1504 is provided with the conductive layer 1530, and the silicon plate 1512 including the longer cantilever 1502 is not. The longer cantilever 1502 is used for the AFM sensor operation to control the distance between the probe 1524 on the shorter cantilever 1504 and the sample, and the shorter cantilever 1504 is used for the detection of the electrical properties of the sample surface by means of the probe 1524 for the STS or STP measurement. Since the longer cantilever 1502, like the cantilever for the conventional AFM measurement, has no conductive layer, it can control the distance between the probe 1524 on the shorter cantilever 1504 and the sample under the same conditions for the AFM measurement. FIGS. 17 and 18 show a cantilever chip with a displacement detecting function applicable to the apparatuses according to the foregoing embodiments in place of the cantilever and the displacement sensor therefor, e.g., the cantilever 302 and the Z-displacement sensor 304 of the apparatus of FIG. 1. The cantilever chip includes a U-shaped cantilever 1702 with a sensor function that utilizes the distortion resistance effect and an elongated rectangular cantilever 1704 inside the cantilever 1702. The cantilever 1702 has a distortion resistance layer therein, which is connected to aluminum electrodes 1708 and 1709 on a support section 1706. The cantilever 1704 has an electrically conductive layer on its probeside electrode surface, and the conductive layer is connected to an aluminum electrode 1710 on the support section 1706. A DC constant voltage source 1732 is connected to the electrode 1708 of the cantilever 1702, while an operational amplifier 1733 for current measurement is connected to the electrode 1709. Also, a current detection circuit 1735 for the detection of the electrical properties of the sample is connected to the electrode 1710 of the cantilever 1704. A DC voltage of several volts or below from the DC constant voltage source 1732 is applied between the electrodes 1708 and 1709 of the cantilever 1702, and the displacement of a probe 1712 on the cantilever 1702 is detected in accordance with a change in resistance of the distortion resistance layer corresponding to a displacement of the cantilever 1702 that is caused by an interactive force between the probe 1712 and the sample surface. The change of the resistance of the distortion resistance layer is detected as a change of a current signal by means of the operational amplifier 1733 for current measurement. In this manner, the cantilever 1702 is used to carry out the AFM sensor operation, thereby regulating the distance between the probe 1714 of the cantilever 1704 and the sample surface and detecting the electrical properties of the sample. Since the cantilever chip can control the distance between the probe and the sample surface by utilizing the sensor function therein, it can detect the electrical properties of the sample without using any external sensor. Accordingly, the cantilever chip itself can be moved to each measuring point for scanning, so that the degree of freedom of the apparatus can be heightened. Preferably, a straight line that connects the probes 1712 and 1714 is coincident with a longitudinal axis that passes through the respective centers of the cantilevers 1702 and 1704. This arrangement allows the probes 1712 and 1714 to be situated further closer to each other. Preferably, furthermore the distance between the probes 1712 and 1714 is restricted to hundreds of micrometers or less. According to this cantilever chip, therefore, the distance between the probe and the sample surface can be set more accurately, so that the electrical properties can be detected with high accuracy. The distance between the probe and the sample may be detected by utilization of excitation-mode AFM measurement. In this measurement, the probe is scanned while oscillating, so that higher resolution is achieved. It is known that the cantilevers, having different lengths and widths, oscillate with different amplitudes. These amplitudes increase in proportion to the lengths of the cantilevers, and decrease in proportion to the widths of the cantilevers. Accordingly, the longer cantilever is liable to oscillate with a wider amplitude than the shorter cantilever. If the amplitude of the longer cantilever is adjusted to a desired value, therefore, it is evident that the cantilever is applicable to the excitation-mode AFM measurement. The amplitude of the cantilever for the excitation-mode AFM measurement is as narrow as about 50 nanometers. Thus, the shorter cantilever is supposed to oscillate with an amplitude further narrower than this, or depending on its lengths hardly to oscillate. It can be said, therefore, that the amplitude hardly has any influence on the detection of the electrical properties by means of the shorter cantilever. For this reason, the distance between the probe on the cantilever and the sample can be set more accurately, so that the electrical properties can be detected with higher accuracy. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

A scanning probe microscope for measuring the electrical properties of the surface of a sample comprises a first sensor for detecting electrical information for the sample surface and outputting a first electrical signal corresponding thereto, the first sensor including an electrically conductive probe located near the surface of the sample, a second sensor for detecting the distance between the probe and the sample and outputting a second electrical signal corresponding thereto, an actuator for relatively moving the probe and the sample in a three-dimensional manner, a servo control mechanism for adjusting the distance between the probe and the sample to a desired value by servo control in accordance with the second electrical signal while the electrical information is being detected by the first sensor, and a processing unit for processing the first electrical signal.

This application is a continuation of U.S. patent application Ser. No. 07/735,203 filed Jul. 24, 1991 and now abandoned, which is a continuation of U.S. patent application Ser. No. 07/386,057 filed Jul. 23, 1989 and now abandoned. TECHNICAL FIELD OF THE INVENTION This invention relates to graphic processor memory storage systems and more particularly to an arrangement for storing pixel information in a nonconfined manner and for accessing the information conveniently. CROSS REFERENCE TO RELATED APPLICATIONS All of the following patent applications are cross-referenced to one another, and all have been assigned to Texas Instruments Incorporated. These applications have been concurrently filed and are hereby incorporated in this patent application by reference. ______________________________________Ser. No. Title______________________________________07/387,568 Video Graphics Display Memory Swizzle Logic and Expansion Circuit and Method (now U.S. Pat. No. 5,233,690)07/898,398 Video Graphics Display Memory Swizzle Logic Circuit and Method (now U.S. Pat. No. 5,269,001)07/387,459 Graphics Floating Point Coprocessor Having Matrix Capabilities (now U.S. Pat. No. 5,025,407)08/143,232 Graphics Processor Trapezoidal Fill Instruction Method and Apparatus08/156,993 Graphic Processor Three-Operand Pixel Transfer Method and Apparatus07/783,727 Graphics Processor Plane Mask Mode Method and Apparatus (now abandoned)07/386,936 Dynamically Adaptable Memory Controller For Various Size Memories (now U.S. Pat. No. 5,237,672)07/387,472 Graphics Processor Having a Floating Point Coprocessor (now abandoned)07/387,553 Register Write Bit Protection Apparatus and Method (now U.S. Pat. No. 5,161,122)07/387,569 Graphics Display Split-Serial Register System (now abandoned)07/387,455 Multiprocessing Multiple Priority Bus Request Apparatus and Method (now abandoned)07/387,325 Processing System Using Dynamic Selection of Big and Little Endian Coding (now abandoned)07/386,850 Real Time and Slow Memory Access Mixed Bus Usage (now abandoned)07/387,479 Graphics Coprocessor Having Imaging Capability (now abandoned)07/387,255 Graphics Floating Point Coprocessor Having Stand-Alone Graphics Capability (now abandoned)07/713,543 Graphics Floating Point Coprocessor Having Vector Mathematics Capability (now abandoned)07/386,849 Improvements in or Relating to Read-Only Memory (now U.S. Pat. No. 5,079,742)07/387,266 Method and Apparatus for Indicating When a Total in a Counter Reaches a Given Number (now U.S. Pat. No. 5,060,244)______________________________________ BACKGROUND OF THE INVENTION In graphics systems, the graphic display information is contained in a graphics memory at specific locations in the memory. This information is then mapped to the video screen in a one-for-one format. To save time and for convenience, the representations on the screen follow each other sequentially, and the same sequential order is used in memory to store the data for each pixel of information on the screen. However, problems arise in that video memories have square characteristics with a fixed number of points in the matrix. A video screen, on the other hand, has a number of points called pixels, with each pixel having a number of bits which must be presented to that pixel. Since it is desired to use the same physical memory for many different screen sizes, it is customary to create the memory having a size at least large enough to directly map the largest number of pixels that would be encountered in any one screen. In order to accomplish this goal and not burden the processor with vast numbers of calculations, there must be some easy mathematical coordination between the memory location and the screen location for any data bit. The importance of such ease of calculations can be appreciated when it is realized that in a typical video graphics system each eight bit pixel must be sent to the screen every 12.7 ns. A typical screen would have a pixel array of 1280 by 1024. The display is refreshed 60 times a second. Time spent in processing address information on a per pixel basis then becomes critically important. There are two basic ways to address a pixel in memory. The first of these is the X-Y coordinate method, which seems to be the natural way to think of memory locations. The second method would be to use a linear or vector address giving location data starting from an arbitrary 00 point. Using this system, the processor must calculate the actual position of each pixel. Problems arise in the calculations, however, unless special steps are taken to organize the data in the memory exactly as it is presented on the screen. Assume for a moment that the memory is 2,000 columns wide, but the number of necessary screen locations would only take up perhaps 1,500 columns. Visualizing this then, one part of the memory would be vacant. This "extra" memory space is hard to use for any other purpose, and thus effectively, wasted. In an attempt to achieve full utilization of the memory, two problems must be solved. One is that there must be a method of removing the information from the ends of the lines of memory and wrapping the end around to the next line of memory. One method of shifting information to a screen is contained in co-pending application entitled "Graphics Display Split Serial Register System", Ser. No. 07/387,569, now abandoned, filed concurrently herewith, which application is herein incorporated by reference. The second problem is the restriction that the pixel size must be a power of 2. This restriction stems from the fact that the processor must be able to easily calculate the address of the first pixel in each next row of pixels. The distance between pixel rows is called the pitch. If memory is to be utilized fully, the addresses must be consecutive with the first address in a screen row being the next binary numerical memory address after the address in the preceding row. Since the number of bits per pixel plus the pitch of the screen must be first multiplied and then added together to translate from an X-Y address to a linear address, it follows that any such calculations, because of their great numbers, must be quickly performed. Thus, it is always desired to reduce such calculations to a simple data shift. This can be accomplished when it is realized that the data is binary and thus multiplication by a power of 2 simply requires a one position bit shift, for each such power. Based upon the need for quick mathematical operations, a restraint is placed on the number of pixels in a row and this restraint limits the number of pixels to powers of 2. Accordingly, a need exists in the art for a system which allows for the utilization of pixels of any size without adding to the processing time for data translation. A need also exists in the art for an arrangement which allows the pixel size to be any number and which allows for the packing and shifting of the bits into consecutive memory space so as to conserve memory capacity. SUMMARY OF THE INVENTION There is disclosed an arrangement which allows a video memory to be packed solid by allowing for coordinate conversion from X-Y to linear by a power of 2 several times, as controlled by an external register. The arrangement allows three different modes of operation for the XY linear conversion based upon the pixel pitch. The first mode is that the pixel number in a row (pitch) is an exact power of 2. In this situation there is a shift for the Y value. The second mode is when the pitch is the sum of two powers of 2. In a situation of 1280 pixels for instance, (which is 1024+256), the conversion can be performed with just one extra shift value. Thus, first there is a shift by the log of 1024 followed by a shift for the log of 256. This results in one extra shift but is still a very quick method. In the third mode where it is desired to use an undefined pitch, a straight multiplication is achieved. This allows full flexibility for the system. Control of the system is accomplished by establishing a register containing the shift values. This register is not precoded, so the linear conversion process itself can use the information in the shift value register to decide which mode it is in. Generally, the shift value register works to control the shifting, with the first value controlling the first power of 2. If that value is a designated value, such as zero, then the system understands that there is no shifting, and the system will perform a multiply. If the register is not 0, the system performs a first shift and will use the register value to control the power of two-shift; then the second digit in the register is looked at and if it is not 0, the system understands to do the sum of two powers of 2. Multiplication is performed when there are no power of 2 shifts set up by the register. It is a technical advantage of this invention that by establishing the shift and multiply values in registers, the memory c an be encoded independent of software and independent of the X-Y linear conversion. Thus, a pitch can be set as desired, and the system will use the best method of conversion. The system allows for better utilization of the memory and less constraints on the system configuration. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and for further advantages thereof, reference is now made to the following Detailed Description, taken in conjunction with the accompanying Drawings, in which: FIG. 1 shows a typical data stream having row and column addresses; FIG. 2 is a representation of one pixel on a screen; FIG. 3 is a representation of a screen superimposed on a memory; FIG. 4 is an equation for calculating the linear address from the X-Y coordinates; FIGS. 5 and 6 show sample calculations; and FIG. 7 shows the registers controlling the system. DETAILED DESCRIPTION OF THE INVENTION The present invention is set in the environment of a graphic processing system where a graphic memory holds display pixel information for presentation to a display. There are a number of such systems, one being shown in patent application Ser. No. 965,561, effectively filed Apr. 27 1989 and assigned to the assignee of this invention. The aforementioned application is incorporated herein by reference. Also incorporated by reference herein is Texas Instruments Inc. User's Guides TMS 34010 and TMS 34020 along with Designer's Handbook TMS 34082. These documents are available to the general public from Texas Instruments Inc., P.O. Box 1443, Houston, Tex. 77251-1443. For convenience and ease of understanding the inventive concepts taught herein there has been no attempt to show each and every operation and data movement since the actual embodiment of the invention in a system will, to a large degree, depend upon the actual system operation in which the inventive concept i s embodied. The mathematical calculations which are required to be performed to achieve the results of the inventive concept can be performed by the floating point coprocessor described in concurrently fi led copending patent application entitled Graphics Processor Having A Floating Point Coprocessor, which application is hereby incorporated by reference herein. The aforementioned coprocessor operates in conjunction with a graphics processor of the type referenced herein or can operate as a stand-alone processor. Before beginning the detailed discussion, a brief review of the problem might be helpful. The problem stems, in part, from a desire to utilize the graphics memory to its fullest extent in the most efficient manner. This problem has several parts, and one important part is disclosed, as discussed above in concurrently filed, copending patent application entitled Graphics Display Split-Serial Register System. Since it is desired to use the same physical memory for many different screen sizes it is customary to create the memory having a size at least large enough to directly map the largest number of pixels that would be encountered in any one screen. In order to accomplish this goal and not burden the processor with vast numbers of calculations there must be some easy mathematical coordination between the memory location and the screen location for any data bit. The importance of such ease of calculations can be appreciated when it is realized that in a typical video graphics system each eight bit pixel must be sent to the screen every 12.7 ns. A typical screen would have a pixel array of 1280 by 1024. The display is refreshed 60 times a second. Time spent in processing address information on a per pixel basis then becomes critically important. Turning now to FIG. 1, there is shown a typical bus address configuration showing column and row addressing for selection of a data bit, or more accurately, a row of data, from the graphic memory. The column and row bits can be 8, 9, 10 and even more depending upon the memory size. These bits can be expressed in hexadecimal format for ease of notation, keeping in mind that hexadecimal translates easily back to binary. The arrangement of data in FIG. 1 is not critical and can be any arrangement allowing for row and column address information to be processed. It is this information that is to be converted to a linear address for presentation to a video display such as that shown in FIG. 2. The FIG. 2 display 20 has pixel point 201 displaced from the upper left corner by a distance X moving from left to right and by the distance Y moving top to bottom. Thus, coordinate position 00 would be in the upper left hand corner for our illustration. The exact physical location of position 00 is determined by a factor called the offset, which is not important to an understanding of this invention, but must be used by the processor to position the display properly. The use of the offset is well-known and will not be detailed herein. Position 201 is defined as a pixel position and can contain any number of bits. The bits control the color, brightness and other attributes of the display at that point. The number of pixels on a row can vary from screen to screen, but typically can be 1280 with 1024 rows. Because of the variation from screen to screen the calculation for conversion from X-Y addressing to linear addressing must be done on a system basis and tailored to each system. Shifting now to FIG. 3 there is shown display 20 superimposed on memory 30. Note that in this figure we have shifted to hexadecimal notation for the screen X and Y coordinates in order to keep the drawing and description of the operation free of unnecessary clutter. In FIG. 3 it will be noted that the first row of pixels is shown as single dots, but it should be understood that each of these dots contain a number of bits. Since the address difference between the first two pixels is 0008h it can be assumed that the pixel size is 8 bits. The next pixel linear address is 0010h in hexadecimal format. These pixels continue across the row and if the row of the screen were coextensive with physical graphic memory 30, then the address numbering would continue into the next row. This is shown by the first dot (pixel) outside the superimposed display boundary in memory 30 being labeled 0200h as is the first dot on row 2. The number 0200h is selected for illustrative purposes and in reality would be a much higher value. Again, this unrealistic number is being used for ease of understanding the operation of the invention. Following this logic, then, if the first pixel on row two of display 20 were to have the next logical linear address after the last linear address 01FFh on the top row of display 20 then that linear address would be 0200h. Thus, the value difference between pixel one of row 1 and pixel one of row 2 is the value 0200h. This value is called the pitch and is dependent upon the number of pixels in each row and the number of bits per pixel. Since the number of bits per pixel plus the pitch of the screen must be first multiplied and then added together to translate from an X-Y address to a linear address it follows that all such calculations, because of their great numbers must be simple to make. Thus, it is always desired to reduce such calculations to a series of additions. This can be accomplished when it is realized that the data is binary, i.e., in a base 2 number system. In such a system, multiplication by a power of the base simply means shifting the bit positions by the number of such powers. When the base is 10, which we are very familiar with, multiplication by two powers of 10 (100) simply means adding two 0's, or shifting the number to the left two places. As we know, 9 times 100 (two powers of 10) is 900 (shifted left twice). So it is with binary numbers. Multiplication of a binary number by one power of 2 means adding one zero (one shifted position). Multiplication by three powers of 2 means adding three 0's. With this as background let us look at the equation in FIG. 4 which establishes the linear address from the X-Y address in accordance with the above discussion. The Y coordinate number (in binary form) is multiplied by the pitch. This result is then added to the product of the X coordinate (also in binary form) multiplied by the pixel size. This total is then added to the offset, which, as we discussed, is not part of this discussion and will be ignored from this point on. Since, as discussed, most systems keep the pixel size a power of two, the X multiplication is a simple shift left 1, 2, 3 or 4 places. In our example, the pixel size is 0008h which translates in binary to (the four LSB least significant bits) 1000. This is 2 to the 3rd power or a left shift of these three places as shown in FIG. 6. Let's now consider the calculation of the linear address of a point in the third column, second row. The row and column address is shown in FIG. 5. Taking the column (x) bits first and converting the least significant four bits to binary as shown in FIG. 6 yields 0010 Shifting that value left three places yields 10000 binary or 10h hexadecimal. Now we turn our attention to the pitch calculation. In the best possible of situations the pitch number would also be a power of two. Then all we would have to know was how many places to shift the y coordinate value. For our example, the two results are added to yield 210h, which we can see from FIG. 3 is the 3rd pixel of row 2. FIG. 7 shows a two part register storing values A and B. The system looks to these registers to determine which type of calculation to make. Mode one controls the easy case where the pitch is an exact power of 2. The value of A would be the required shift value corresponding to the proper power of 2 and thus would direct the processor to perform a left shift the number of positions set forth in value A. This arrangement also allows for situations where the (Y) address bits are presented in the most significant half of the register. By adjusting the value of A, a right shift can be performed to compensate for this bit positioning. Mode two is the situation where the pitch is calculated to be the sum of two powers of two. This then provides more flexibility to the system and allows a wider range of pitch values, still without causing a significant change in processing time. In this mode, value A controls the number of left shifts of Y for the first operation creating a first result. Value B controls the number of shifts of Y creating a second result. These two results are added together to give the Y portion of the linear address. The X position is, as we discussed, a power of 2 and thus also a simple shift. In mode one, the calculations typically require two processor cycles. In mode two, three cycles are required. This is not a harsh penalty to pay for the increased pitch flexibility. Mode three is a different story altogether. In this situation, the pitch is arbitrary and thus simple shifting can not be performed. Full multiplication must be used. Mode three is signified to the processor by a designated value, such as a 0, as value A. Under this condition, a full multiply must be undertaken where the Y coordinate value must be multiplied by the pitch value. This is full 16-bit by 32-bit multiplication and typically would require 15 processor cycles. Thus, while a high time penalty is paid for flexibility, this may be a better trade-off for some situations than being forced to limit pitch characteristics which otherwise could be beneficial to a user. This system, then, provides the user with a high degree of design choice using the simple loading of two registers to control the process. While the specific embodiment discussed shows two shift values A and B, it must be understood that many shift values could be used to arrive at a result. The alternative would be to use a hardware multiplier which would utilize valuable space. Although the present invention has been described with respect to a specific preferred embodiment thereof, various changes and modifications may be suggested by one skilled in the art, and it is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.

A graphics processing system allows for fuller utilization of memory space by allowing freedom in performing X-Y conversions to linear addressing for graphics display. The system takes advantage of the fact that many display pitch dimensions can be defined in terms of powers of 2, thereby allowing for simple shifts in the binary value followed by an addition of two such shifted numbers. For non-even situations full multiplication by the pitch is available. This operation is controlled by the values in two registers, which values in turn control the actual shifting and multiplication functions.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority of U.S. Provisional Patent Application No. 61/104,863 entitled “LARGE FLAME TORCH WITH TEXTURED FLAME BOWL,” filed Oct. 13, 2008, the contents of which are hereby incorporated by reference. FIELD OF THE INVENTION [0002] This disclosure is related to liquid fueled torches in general and, more specifically, to a liquid fueled torch with flame enhancing features. BACKGROUND OF THE INVENTION [0003] Patio torches, also know as lawn torches or garden torches, may be used to provide lighting or decoration. Sometimes, scented oils or insect repellant oils are burned in the patio torches for additional effect. A torch may include a refillable canister that accepts liquid fuel. A torch may be mounted on or otherwise integrated with a decorative pole for display purposes. [0004] The actual utility of a torch, in terms of light or aroma given off and the ability to repel pests, may be less than desirable. The wick is often too small, relatively speaking, to provide an effective amount of combustion. Even with larger diameter wicks or wicks that are extendable to create a larger surface area, air and flame control may become problematic, resulting in a flame that may still be too small to create the desired effect. [0005] What is needed is a device for addressing the above and related problems. SUMMARY OF THE INVENTION [0006] The invention of the present disclosure, in one aspect thereof comprises an apparatus with a fuel container and a flame bowl atop the fuel container. The flame bowl has a wick proximate the center thereof, the wick extending into a fuel supply within the fuel container. The flame bowl has an interior surface that is texturized to enhance the appearance of the flame. The interior surface may be texturized in such a way to promote capillary action of fuel away from the wick. The interior surface may also be texturized in such a way to promote charring on the interior surface. In various embodiments, the interior surface may be texturized by a plurality of nubs, by peening, and/or by knurling. The flame bowl may provide a substantially flat floor and/or a wick holder for the wick. BRIEF DESCRIPTION OF THE DRAWINGS [0007] FIG. 1 is a perspective cutaway view of a large flame patio torch with a flame enhancing combustion bowl according to aspects of the present disclosure. [0008] FIG. 2 is a perspective cutaway view of another large flame patio torch with a flame enhancing combustion bowl according to aspects of the present disclosure. [0009] FIG. 3 is a perspective cutaway view of another large flame patio torch with a flame enhancing combustion bowl according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] Referring now to FIG. 1 , a perspective cutaway view of a large flame patio torch according to aspects of the present disclosure is shown. Although the torch 100 is referred to as a patio torch, for purposes of the present disclosure this term is synonymous with any type of recreational, decorative, or insect-repellant torches such as garden torches or table top torches. The torch 100 may be used as an insert with a stand or other display device to create a torch assembly. In some embodiments, the torch 100 is used as a stand-alone item. [0011] The major components of the torch 100 seen in FIG. 1 comprise a funnel, bowl, or flame guard 104 , a neck 105 , and a canister 106 . These pieces may be formed integrally or may be formed separately and attached. In one embodiment, each of these components is made from rolled or stamped sheet metal that may be spot welded or glued together. In other embodiments, a more durable build may be accomplished by using cast or machined pieces. In some embodiments, some parts of the torch 100 may be plastic or another material. [0012] The bowl 104 and/or neck 105 may be separable from the canister 106 for refilling of a torch fuel 408 and/or attaching to other fuel sources. In the present embodiment, the neck 105 and canister 106 have a threaded fitting 107 . Other embodiments may provide friction fits or other fittings. In some embodiments, fuel filling and/or ventilation ports 108 may be provided. The ventilation ports 108 are only for illustration as other ports or locations are contemplated. The fuel 408 may be a citronella oil or another oil suitable for burning in a decorative or insect repellant torch. [0013] A wick 202 , used for combustion of the fuel 408 , may be a cotton wick, a fiberglass wick, a polyester wick, or another type of wick using these or other materials and/or combinations thereof. Although only a single wick 202 is shown, the present disclosure is not so limited. Multiple wicks may be provided that are capable of simultaneous or selective operation. A wick holder 406 may be sized to retain the wick 202 in a friction fit. [0014] The bowl 104 in the present embodiment is generally conically or funnel shaped with a relatively flat floor. However, in other embodiments, a more rounded floor will be provided. In the present embodiment, the interior surface 102 of the bowl 104 is textured with raised nubs. It can be seen that the texturing or nubbing proceeds along the floor of the bowl 104 up to the wick holder 406 . In some embodiments, the wick holder 406 will be textured as well. In other embodiments, the wick 202 may be held in place by an opening in the floor of the bowl 104 . [0015] In operation, depending upon the size and spacing of the nubs on the surface 102 of the bowl 104 , fuel may be drawn or wicked by capillary action or seepage away from the wick 406 prior to being burned. This fuel may come to coat or otherwise saturate the interior surface 102 of the bowl 104 . In this event, the fuel may begin to vaporize due to the heat from the flame on the wick 202 . In other cases, depending upon the fuel used, the fuel may actually burn on the interior surface 102 of the bowl 104 . This additional burning will be in a controlled fashion, owing in part to the limited amount of fuel that can be wicked away by capillary action or seepage from the wick 202 . [0016] The burning or vaporization of the fuel on the surface 102 will serve to enhance the effects of the flame on the wick 202 . A larger flame than would normally be supported by the wick 406 may be seen to appear to fill the bowl 104 during operation. Additionally, insect repellant functions or scent dispersant functions may be enhanced by the additional fuel consumed or otherwise vaporized on the surface 102 . In some embodiments, the vaporization and/or burning of the fuel on the interior surface 102 of the bowl 104 will cause charring or aching on the surface 102 . This may serve to enhance the capillary action and/or seepage of the fuel 408 . This may, in turn, increase the surface area for even greater burning or vaporization of fuel. [0017] Referring now to FIG. 2 , a perspective cutaway view of another large flame patio torch with a flame enhancing combustion bowl according to aspects of the present disclosure is shown. In this embodiment, the bowl 104 has an interior surface 202 that has been peened to produce a texture. The peening of the surface 202 functions in a similar fashion as the nubbing of the surface 102 of FIG. 1 . The peening promotes fuel seepage and/or charring on the surface 202 . This enhances the appearance of the flame and the vaporization of additional fuel. In some embodiments, the wick holder 406 will be peened or otherwise textured. The wick holder 406 may be an integral component of the bowl 104 . As before, the actual shape of the bowl 406 may vary. The fuel source may be separable from the flame bowl 104 and ventilation (not shown) may be provided. [0018] Referring now to FIG. 3 , a perspective cutaway view of another large flame patio torch with a flame enhancing combustion bowl according to aspects of the present disclosure is shown. This embodiment is substantially similar to those previously discussed. Here an inner surface 302 of the bowl 104 has been etched with a cross-hatch or knurled pattern. This cross-hatching serves a similar function as the nubbing or peening of previous embodiments. Once again, the wick holder 406 may also be knurled and may be an integral part of the bowl 104 . The knurled interior surface 302 promotes fuel seepage from the wick that enhances the flame during operation and may also provide additional vaporization of fuel 408 . Charring that may occur on the surface 203 further serves to enhance the seepage of fuel, the flame effects, and the vaporization of fuel. As with the pervious embodiments, the flame bowl 104 and ventilation of the fuel source (not shown) may be provided. [0019] In each of the embodiments discussed above, various means are utilized to provide enhanced fuel burning and/or vaporization (producing a more active flame). It is understood that a wide variety of patterns, textures, or surface treatments could be utilized to interrupt the otherwise smooth surface and thereby allow for wicking of fuel and a more active flame. For example, an applied surface texturizing treatment or coating could be utilized. In some embodiments, painted on finishes may be utilized. Paints may be utilized that have sand or other texturizers suspended therein. Spray on insulations or other fire resistant materials may also be used. Furthermore, the density and/or depth of the nubbing, peening, knurling, or other treatment can be varied to increase or decrease the flame enhancing effects of the same. In some embodiments, designs may be etched, scored, or carved into the flame bowl. [0020] Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.

An apparatus with a fuel container and a flame bowl atop the fuel container is disclosed. The flame bowl has a wick proximate the center thereof. The wick extends into a fuel supply within the fuel container. The flame bowl has an interior surface that is texturized to enhance the appearance of the flame.

PRIORITY This application is a Divisional of U.S. application Ser. No. 09/847,001, filed on May 1, 2001 now abandoned which claims priority to an application entitled “Method for Controlling a Priority Access and Channel Assignment Call in a Mobile Telecommunications System” filed in the Korean Industrial Property Office on Jun. 1, 2000 and assigned Serial No. 2000-30012, the contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile telecommunication system, and more particularly to an apparatus and a method for controlling a priority access and channel assignment call in a mobile telecommunication system. 2. Description of the Related Art Generally, the priority access and channel assignment (PACA) call is a channel assignment service provided to a subscriber. PACA allows a subscriber to obtain communication priority, so that when a user requests a base station (BS) make a call to a mobile station that is presently not available because its traffic channel is receiving too much traffic then the mobile station (MS) switches to a standby mode so that it may be assigned to the traffic channel when the traffic channel is idle and available. Here, the standby mode of the MS is defined as the “PACA state”, which is described in connection with FIGS. 1 and 2 . Referring to FIG. 1 there is illustrated a schematic diagram of a conventional mobile telecommunication system. It consists of a Public Switch Telecommunications Network (PSTN) 160 , a Public Land Mobile Network (PLMN) 150 , a mobile switching center (MSC) 130 , a home location register (HLR) 140 , a base station controller (BSC) 120 , a base station (BS) 110 , and an MS 100 . MS 100 communicates with both PSTN 160 and PLMN 150 . The BSC 120 performs both wired and wireless link control and hand-off. The BS 110 provides the wireless traffic channel to MS 100 , which manages wireless traffic resources. The HLR 140 registers the subscriber's location, although, not shown, the visitor location register (VLR) does the same function. In FIG. 2 , there is illustrated a flow diagram that depicts a conventional process for shifting the MS to the PACA state. MS 100 is requested by the user to send a signal in step 211 . If MS 100 does not request a signal be sent, then the signal stays at MS 100 . In step 213 , if MS 100 requests a signal be sent, MS 100 transmits an origination message to BS 110 . BS 110 sends the signal as a call service request message “CM_SERVICE,” REQ to MSC 130 , in step 215 . Then, if MSC 130 sends an assign request message, “ASSIGN REQ” to BS 110 to assign a traffic channel for the origination message, in step 217 , the BS 110 detects an available or idle traffic channel, in step 219 . If there exists an idle traffic channel, the BS 110 assigns it to the MS 100 , in step 221 . However, if there is no idle traffic channel, the BS 110 places the MS 100 in the PACA state. Then BS 110 , sends a PACA message to the MS 100 , in step 225 , while it also sends a channel assign fail message, “CH_ASSIGN_FAIL” which represents failure in the attempt to assign a traffic channel to the MSC 130 , in step 227 . Meanwhile, the MS 100 receives the PACA display message that states, “PACA-State” which informs the user, in step 229 , that the MS 100 has been shifted to the “PACA-State.” As previously stated, the PACA state indicates that the BS 110 cannot assign an available traffic channel, with a communication priority, to the MS 100 because there is no available channel. MS 100 is placed on a standby mode for a predetermined time, for example 1 minute, to periodically re-send the origination signal, until the BS 110 detects an idle traffic channel assigned to the MS. In this case, the BS 110 determines whether the MS 100 has the communication priority or not, based on the subscriber's information of the MS 100 contained in the assign request message received from the MSC 130 . Thus, if an idle traffic channel occurs in the BS 110 , the MS 100 is immediately connected to it from the PACA state to establish a communication channel. However, the aforementioned conventional method does not provide the MSC 130 a method to distinguish when the MS 100 has been assigned to a traffic channel during the PACA state from the MS 100 that has been assigned to a traffic channel through the ordinary assignment process, especially in charging the subscriber. In addition, when the MS 100 is handed off from one BS to another, the former BS unnecessarily stores the subscriber's information of the MS 100 , thereby increasing consumption of the resources. Moreover, when the MS 100 re-sends the origination signal in the PACA state, the subscriber's information is additionally stored and maintained in the BS, which also increases consumption of the resources as in handoff. Therefore, a need exists for an apparatus and method that can be utilized to distinguish the MS that has been assigned to a traffic channel during the PACA state from the MS that has been assigned a traffic channel through an ordinary assignment process. In addition, there exists a need for an apparatus and method that does not store a subscriber's information of a MS. SUMMARY OF THE INVENTION It is an oject of the present invention to provide a method for controlling a PACA call in a mobile telecommunication system, which may distinguish the PACA call from the ordinary call in charging the communications services. It is another object of the present invention to provide a method for controlling a PACA call in a mobile telecommunication system, which may delete the PACA call information from the BS from which the MS is handed off to a new BS, thereby improving the storage efficiency of the PACA buffer. It is still another object of the present invention to provide a method for controlling a PACA call in a mobile telecommunication system, which may delete the PACA call information previously stored in the BS when the MS in the PACA state, sends a new origination signal which is received and stored by the BS. It is still another object of the present invention to provide a method for controlling a PACA call in a mobile telecommunication system, which may delete the PACA call information stored in the BS when the MS deletes it, thereby improving the storage efficiency of the PACA buffer. It is yet another object of the present invention to provide a method for controlling a PACA call in a mobile telecommunication system, which may send a busy tone signal to a caller who has sent a call signal to the MS in the PACA state without requesting the MS to receive it. According to the present invention, a method for controlling a PACA call in a mobile telecommunication system, comprises: sending a new origination message from a mobile station in the PACA state to a base station; sending a service request message for the PACA call from the base station to a mobile switching center; requesting from the mobile switching center that the base station assign a traffic channel to the mobile station; assigning an available traffic channel to the mobile station to start a communication; and distinguishing the PACA call service from an ordinary call service. The present invention will now be described more specifically with reference to the drawings attached only by way of example. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages of the present invention will become more apparent in light of the following detailed description of an exemplary embodiment thereof taken in conjunction with the attached drawings in which: FIG. 1 illustrates a schematic diagram that depicts the structure of a conventional mobile communication system; FIG. 2 illustrates a flow diagram that depicts the process of shifting an MS to the PACA state, according to the conventional method; FIG. 3 illustrates a flow diagram that depicts shifting an MS to the PACA state and assigning a traffic channel thereto, according to the present invention; FIG. 4 illustrates a flow diagram that depicts updating the PACA call information of the MSC, according to the present invention; FIG. 5 illustrates a flow diagram that depicts handing off the PACA call, according to the present invention; FIG. 6 illustrates a flow diagram that depicts sending a reorigination message for the PACA call; FIG. 7 illustrates a flow diagram that depicts canceling the PACA call, according to the present invention; and FIG. 8 illustrates a flow diagram that depicts controlling a call signal directed toward the MS in the PACA state, according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Throughout the description, in connection with the drawings, there are omitted detailed descriptions of the conventional parts not required to comprehend the technical concept of the present invention. The terms used in this specification are only to help understand descriptions of the essential functions connected with the invention, and should be interpreted based on the meaning the whole specification intends to convey including the attached claims. Hereinafter described is the inventive system of controlling a PACA call in connection with FIGS. 1 and 3 to 7 . There is a description of the first process of shifting an MS to the, PACA state “PACA_STATE” and assigning a traffic channel thereto with reference to FIG. 3 . e MS 100 is requested by the user to send a signal, in step 311 , then it sends the signal in the form of an origination message to a BS 110 , in step 313 . Then, the BS 110 sends an acknowledge order message, “BS_ACK_ORDER_MSG” to the MS 100 , in step 315 , and a communication service request message “CM_SERVICE_REQ” to the MSC 130 , in step 317 . The MSC 130 sends a subscriber's information request message “MS_CgVSvcingRQ_Msg” to the HLR 140 /VLR (not shown) to request the subscriber's information of the MS 100 , in step 319 . The HLR/VLR retrieves the subscriber's information loaded on a subscriber's information response message, “MS_CgVSvcing” (PACA call flag) delivered to the MSC 130 , in step 321 . In this case, the subscriber's information response message contains states, “PACA_Call_flag” which is set to have a predetermined value, for example 1 if the MS has priority for the PACA call. The MSC 130 receives the subscriber's information response message, then sends a channel assign request message, “ASSIGNMENT_REQ” to request the BS 110 assign a traffic channel to the MS 100 , in step 323 . The channel assign request message contains “queuing allowed” information to allow the PACA call because the subscriber's information represents priority for the PACA call. Then, the BS 110 detects, in step 325 , if there is an available or idle traffic channel to be assigned to the MS 100 to have a normal communication, in step 327 . In this case, if there is no idle traffic channel, the BS 110 places the MS 100 in the PACA state “PACA_STATE,” in step 329 , then sends a channel assign fail message “Assignment_Fail” to the MSC 130 , in step 331 . The channel assign fail message states “PACA call queued” information, which shows that the MS 100 has been shifted to the PACA state “PACA_STATE,” where information is stored in the PACA buffer of the BS 110 . Although, not shown, the MSC 130 notifies the HLR 140 /VLR that the MS 100 is in the, PACA state “PACA_STATE.” Meanwhile, the BS 110 stores the PACA call of the MS 100 in the PACA buffer, sending, in step 333 , a PACA call storage message to the MS 100 , which represents the address, for example, “00000” of the PACA call queue message stored in the PACA buffer. Whenever the address of the PACA call queue is changed, the BS 110 sends the PACA call storage message to inform the MS 100 of the changed address, for example “00001”, in step 335 . Subsequently, if the BS 110 detects an idle traffic channel, in step 337 , the MS 100 is notified of it. Then, the MS 100 sends, in step 339 , the reorigination message to the BS 110 , which in turn sends a communication service request message “CM_SERVICE_REQ” to the MSC 130 , in step 341 . In this case, the communication service request message contains the PACA reorigination indicator “PACA_REORIG”, which indicates that the reorigination message is a PACA call. The MSC 130 , sends in step 343 , the subscriber's information request message to the HLR 140 /VLR, which, in turn, sends the subscriber's information response message to the MSC 130 . Receiving the subscribcr's information response message, the MSC 130 sends, in step 347 , the channel assign request message to the BS 110 to assign a traffic channel for the reorigination message to the MS 100 in step 349 . Then, the BS 110 sends the channel assignment message, “Channel_Assignment,” in step 351 . After the MS 100 has completed communication, the MSC 130 distinguishes the PACA call service from the ordinary call service in charging the subscriber based on the PACA reorigination indicator “PACA_REORIG” contained in the reorigination message. The process of updating the PACA call in the MSC is described in connection with FIG. 4 . Receiving an origination message, in step 411 , the MSC 130 determines, in step 413 , whether the origination message is the PACA call or not. If not, the MSC 130 treats it as the ordinary call in step 415 . However, if the origination message is indicative of the PACA call, then the MSC 130 requests the HLR 140 /VLR to send the subscriber's information of the origination message, which is analyzed to determine, in step 417 , whether the subscriber's registered location of the origination message agrees with the registration of the HLR/VLR or not. If they do not agree, the MSC 130 determines if the MS 100 has been handed off from the previous BS to a new BS, then sends a first PACA call update message to the previous BS. The first PACA call update message requests the previous BS delete the PACA call information from the PACA buffer because the previous BS need not deal with it. The process of dealing with the PACA call concerning the handoff of the MS 100 will be described in connection with FIG. 5 . Meanwhile, if the subscriber's registered location of the origination message agrees with the origination message registered in HLR/VLR, then the MSC 130 determines whether the MS 100 is enabled for the “PACA_STATE” in HLR 140 /VLR, in step 421 . If the MS is enabled for the PACA state, the MSC 130 determines, in step 423 , whether the cell ID of the origination message agrees with the origination message registered in HLR/VLR. If they agree, the MSC 130 determines that the MS has sent a new origination message in the PACA state, then sends a second PACA call update message to the base station in step 425 . The second PACA call update message requests the BS 110 delete the previous PACA call stored in the PACA buffer because of the new origination message. The process of dealing with the new PACA call generated from the MS 100 in the PACA state “PACA_STATE” will be described in connection with FIG. 6 . Referring to FIG. 5 there is a description of the process of dealing with the PACA call concerning the handoff of the MS 100 in connection with FIG. 5 . The MS 100 sends the origination message to the first BS on request by the user, in step 511 . Then, the first BS sends the BS acknowledge order message to the MS 100 , in step 513 , and the communication service request message to the MSC 130 , in step 515 . The MSC 130 , sends, in step 517 , the subscriber's information request message to HLR 140 /VLR to retrieve the subscriber's information of the MS 100 . The HLR/VLR loads the retrieved subscriber's information on the subscriber's information response message delivered to the MSC 130 , in step 519 . The subscriber's information response message, “PACA_Call_flag” is set to have a predetermined value, for example 1 if the MS has priority for the PACA call. The MSC 130 receives the subscriber's information response message, then sends a channel assign request message to request the first BS 110 to assign a traffic channel to the MS, in step 521 . The channel assign request message contains “queuing allowed” information to allow the PACA call, because the subscriber's information of the MS 100 represents priority for the PACA call. Then, the first BS 110 detects an available or idle traffic channel. If there is no idle traffic channel, the first BS determines that the MS 100 is in the PACA state “PACA_STATE,” which indicates the storage of the origination message of the MS 100 as the PACA call in the PACA buffer. The PACA call is sent as a storage message that represents the address of the PACA call queue in the PACA buffer, for example “00000” to the MS 100 , in step 523 . In addition, the first BS sends the channel assign fail message to the MSC 130 , in step 525 . The channel assign fail message contains the PACA call queued information representing that the PACA state of the MS 100 has been stored in the PACA buffer of the BS 110 . Subsequently, the MSC 130 receives the channel assign fail message, then sends the MS an information update message, “MS_CallReleaseRP PACA_STATE,” to VLR to update the information of the MS. The MS information update message contains the information representing that the MS 100 has been shifted to the PACA state “PACA_STATE” stored in the PACA buffer. Meanwhile, if the MS 100 is handed off from the previous BS (hereinafter referred to as “first BS”) to another BS (hereinafter referred to as “second BS”), in step 529 , it sends a new origination message containing the PACA reorigination indicator “PACA_REORIG” to the second BS, in step 531 . Then, the second BS sends the BS acknowledge order message to the MS 100 , in step 533 , and the communication request message including the PACA reorigination indicator to the MSC 130 , in step 535 . The MSC 130 , in turn, sends the subscriber's information request message to the VLR to provide the subscriber's information of the MS 100 , in step 537 . Then the VLR retrieves the subscriber's information loaded on the subscriber's information response message delivered to the MSC 130 , in step 539 . In this case, the subscriber's information response message includes both the status information of the MS 100 being in the PACA state and the location information of the MS 100 registered in the VLR. Then the MSC 130 sends a first PACA update message to the first BS, in step 541 . The first PACA update message is the message requesting the first BS to delete the PACA call stored in the PACA buffer of the first BS because the MS 100 has been handed off from the first to the second BS. Hence, the first BS sends the PACA update response message to the MS after deleting the PACA call from the PACA buffer, in step 543 . Then, the MSC 130 sends the channel assign request message to the second BS to assign a traffic channel, in step 545 . The second BS sends the channel assign message to notify the MS 100 that a traffic channel has been assigned to it, in step 547 , so that the MS 100 performs an ordinary communication, in step 549 . Terminating the communication, the MSC 130 sends the information update message of the MS to the VLR to delete the PACA state information of the MS 100 , in step 551 . Referring to FIG. 6 , there is a description of the process of managing the PACA call when the MS 100 sends a new PACA call in the PACA state “PACA_STATE.” If the MS 100 , while being in the PACA state, in step 611 , sends a new origination message containing the PACA reorigination indicator, “PACA_REORIG” to the BS 110 , in step 613 , then the BS 110 sends the BS response order message to the MS 100 , in step 615 . Then, the BS 110 sends the communication service request message containing the, “PACA_REORIG” indicator to the MSC 130 , in step 617 , so that the MSC 130 sends, in step 619 , the subscriber's information request message to the VLR to obtain the subscriber's information. The VLR retrieves the requested subscriber's information loaded on the subscriber's information response message delivered to the MSC, in step 621 . In this case, the subscriber's information response message includes both the status information of the MS 100 being in the PACA state and the location information of the MS 100 registered in the VLR. Then the MSC 130 sends a second PACA update message to the BS 110 , in step 623 . The second PACA update message is the message requesting the BS to delete the previous PACA call stored in the PACA buffer of the BS because the MS 100 has sent the new origination message requesting again the PACA call. Hence, the BS 110 sends the PACA update response message to the MS 130 after deleting the previous PACA call from the PACA buffer, in step 625 . Then, the MSC 130 sends the channel assign request message to the BS 110 to assign a traffic channel, in step 627 . Then, the BS 110 detects an available traffic channel to assign to the MS. If BS 110 does not detect an available traffic channel, then the BS 110 stores the PACA call into the PACA buffer, sending, in step 629 , the channel assign fail message containing the PACA call queued information to the MSC 130 . The MSC 130 sends the PACA call update message to the VLR to update the PACA state of the MS 100 , in step 631 . In addition, the BS 110 sends the PACA storage message containing the PACA call state representing the storage location of the PACA call in the PACA buffer to the MS 100 , in step 633 . Describing the process of canceling the PACA call in connection with FIG. 7 , the MS 100 detects the PACA call cancellation entered by the user, in step 711 . If MS 100 detects the PACA call cancellation entered by the user, then the MS sends the PACA cancellation message to the BS 110 in step 713 , so that the BS 110 sends the BS response order message to the MS 100 , in step 715 , which deletes the PACA call from the PACA buffer. The PACA update message, indicates that the MS 100 has been released from the PACA state to the MSC 130 , in step 717 . Then, the MSC 130 sends, in step 719 , the MS PACA update message “MS_PACAUpdateRP,” indicates that the MS 100 has been released from the PACA state to the VLR, and the PACA update response message to the BS 110 , in step 721 . Of course, the PACA call may also be cancelled by the BS 110 . Referring to FIG. 8 , there is a description of the process of warding off a call from the MS in the PACA state in connection with FIG. 8 . The MSC 130 retrieves the receiving subscriber's information of the call detected, in step 811 , to analyze it, in step 813 , thereby determining, in step 815 , whether the receiving subscriber is in the PACA state or not. If the receiving subscriber is in the PACA state, the MS 130 sends the busy tone to the subscriber requesting the call, in step 817 . Alternatively, if the receiving subscriber is not in the PACA state, the MSC 130 sends a paging message to the BS 110 registering the receiving subscriber, in step 819 , which in turn transfers it to the MS 100 , in step 821 . Then, the MS 100 sends the paging response message to the BS 110 in step 823 , which in turn transfers it to the MSC 130 , in step 825 . Then, the MSC 130 sends the channel assign request message to the BS 110 , in step 827 , so that the BS 110 assigns, in step 829 , a traffic channel to the MS 100 shifted to the communication stated, in step 831 . Thus, the present invention provides a mobile telecommunication system with means to distinguish the PACA call from the ordinary call in charging the communications services. In addition, the present invention deletes the PACA call information from the BS when the MS is handed off to a new BS or when the MS in the PACA state. Then, the present invention sends a new origination signal or when the MS BS cancels the PACA call, thereby improving the storage efficiency of the PACA buffer. Further, the present invention sends the busy tone signal to a caller who has sent a call signal to the MS in the PACA state without requesting the MS to receive it. While the present invention has been described in connection with specific embodiments accompanied by the attached drawings, it will be readily apparent to those skilled in the art that various changes and modifications may be made thereto without departing from the gist of the present invention.

Disclosed is a method for controlling a PACA call in a mobile telecommunications system, which comprises: sending a new origination message from a mobile station in a PACA state to a base station; sending a service request message for a PACA call from the base station to a mobile switching center, requesting from the mobile switching center the base station to assign a traffic channel to the mobile station; assigning an available traffic channel to the mobile station to start a communication; and distinguishing the PACA call service from an ordinary call service.

CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit under 35 USC §119(e) of U.S. Provisional Application No. 60/811,222 filed Jun. 5, 2006, the contents of which in its entirety is hereby incorporated by reference. BACKGROUND OF INVENTION This invention relates generally to yttrium phosphate and a method for producing it in commercial quantities, and is particularly concerned with a pure or single phase yttrium phosphate having the xenotime crystal structure and a process for synthesizing it without utilizing extremely high temperatures. In recent years many researchers have explored the use of yttrium phosphate in the field of ceramic materials. Yttrium phosphate appears to be valuable for use in laminate composites, as a fiber-matrix interface in ceramic matrix composites and as coatings for thermal protection. It appears to be particularly useful as a coating because of its resistance to expansion when exposed to high temperatures. Although the synthesis of yttrium phosphate by various researchers has been reported, either via expensive high-temperature solid state reactions and wet chemical precipitation, large quantities of yttrium phosphate for commercial applications do not appear to be available. Furthermore, it is very important in the field of ceramic materials processing that any yttrium phosphate utilized be free of secondary phases and other impurities. Thus, there is a distinct need for the development of relatively inexpensive methods to synthesize large quantities of pure or single phase yttrium phosphate, especially yttrium phosphate having the xenotime crystal structure. SUMMARY OF THE INVENTION In accordance with the invention, it has now been found that pure phase yttrium phosphate with the xenotime crystal structure can be synthesized using a relatively low temperature process that begins by forming a slurry of a solid and relatively insoluble yttrium compound, preferably yttrium oxide, in water. Phosphoric acid is then added to the slurry in an amount less than the stoichiometric amount required to form yttrium phosphate. Thus, the mole ratio of yttrium to phosphorus in the slurry is greater than 1.0. An inorganic acid, preferably nitric acid, is then added to the slurry to react with the excess yttrium compound and thereby form a water-soluble yttrium salt. The solid yttrium phosphate formed by the reaction of the yttrium compound with the phosphoric acid, which is substantially free of any excess phosphoric acid and yttrium compound, is then removed from the slurry, washed to remove soluble impurities and dried, usually at temperatures well below 1000° C. The resultant material is a single or pure phase yttrium phosphate having the xenotime crystal structure that is free of unreacted yttrium compound and phosphoric acid and contains no other forms of yttrium phosphate. The fact that this pure phase yttrium phosphate can be made without the need to utilize temperatures above 1000° C. means that the use of the process of the invention results in substantial cost savings. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are XRD patterns. In particular, FIG. 1 is an XRD pattern of a sample obtained from an in-progress test after phosphoric acid addition, then filtered, washed and dried at 1,000° C., while FIG. 2 shows the transformation to single phase yttrium phosphate after reaction with mineral acid, washing and drying to 1,000° C. FIGS. 3 and 4 are images of Thermogravametric (TGA) and Differential Scanning Calorimetry tests performed on the same samples as FIGS. 1 and 2 . DETAILED DESCRIPTION OF THE INVENTION The first step in the process of the invention for producing commercial amounts of yttrium phosphate is the formation of a slurry containing a yttrium compound. Any solid yttrium compound that is relatively insoluble in water can be used. Typically, the yttrium compound will have a solubility less than about 0.1 grams/liter. Examples of yttrium compounds that can be used include yttrium oxide, yttrium carbonate, yttrium bicarbonate and hydroxide. Generally, enough of the solid yttrium compound is mixed with water so that the resultant slurry contains between about 0.5 and 50 weight percent solids, preferably between about 3.0 and about 20 weight percent, and more preferably between about 5 and 15 weight percent. While the aqueous slurry of the yttrium compound is vigorously agitated, phosphoric acid is added to form yttrium phosphate. It has been found that using a stoichiometric amount of phosphoric acid results in the formation of yttrium phosphate containing unreacted yttrium compound and unreacted phosphoric acid as well as non-xenotime yttrium phosphate. It is theorized that this contaminated yttrium phosphate results from an incomplete reaction due to the encapsulation of unreacted yttrium compound and the slow disassociation of phosphoric acid. It has been surprisingly found that limiting the amount of the phosphoric acid that is added to less than the stoichiometric amount needed ultimately results in the formation of a pure single phase yttrium phosphate with the xenotime mineral structure. Thus, the phosphoric acid is added to the aqueous slurry of the yttrium compound in an amount that is less than the stoichiometric amount required for the formation of yttrium phosphate. Generally, a 75 to 85 weight percent solution of phosphoric acid is added to the slurry over a period of about 15 minutes to about 90 minutes as the slurry is continuously agitated and maintained at a temperature that typically ranges between about 20° C. and about 70° C. The amount of the phosphoric acid added to the slurry is usually about 1.5 molar percent less than the amount of the yttrium compound present in the slurry. When the yttrium compound used is yttrium oxide, the reaction takes place to form yttrium phosphate, minor amounts of yttrium oxide, minor amounts of surface adsorbed phosphoric acid and water. The yttrium phosphate formed comprises approximately 95.5 percent of the solids portion in the slurry. In order to remove the excess yttrium oxide and phosphoric acid from the solids in the slurry, a small amount of an inorganic acid is added to the slurry. The acid releases the yttrium compound and phosphoric acid from the yttrium phosphate and allows them to react on their own until the phosphoric acid is consumed. The 1.5 molar percent excess of the yttrium compound reacts with the acid to form a soluble yttrium salt which dissolves in the aqueous phase of the slurry. When yttrium oxide is used as the yttrium compound and nitric acid is used as the inorganic acid, the reaction provides soluble yttrium nitrate which combines with the remaining phosphoric acid to produce yttrium phosphate solids and with minor amounts of yttrium nitrate in solution. The yttrium phosphate, which at this point in the process has the crystal structure of the mineral churchite (hydrated yttrium phosphate), is then separated from the aqueous phase by filtration, centrifugation or other liquid-solids separation technique. Although nitric acid is used for purposes of illustration, many other inorganic acids can normally be utilized to solubilize the excess yttrium compound to remove it from the precipitated yttrium phosphate. Examples of such acids include hydrobromic acid, hydroiodic acid, and sulfuric acid. Once the yttrium phosphate is removed from the aqueous phase of the slurry, it is normally washed with water to remove any residual soluble impurities and then dried at temperatures below 1000° C. It has been found that the yttrium phosphate removed from the aqueous slurry is ultra high purity, single phase needle crystals of the mineral churchite and is essentially free of unreacted constituents and non-churchite yttrium phosphate. The drying step is only needed to drive off moisture converting the yttrium phosphate from the churchite to the xenotime crystal structure and not to decompose unreacted yttrium compound, phosphoric acid, or other impurities. The conversion from churchite to xenotime crystal structure occurs at approximately 300° C. In view of this, substantial cost savings can be obtained by drying the yttrium phosphate at relatively low temperatures between about 300° C. and 900° C., preferably at a temperature below 500° C. The yttrium phosphate recovered from the drying step is substantially pure single phase yttrium phosphate of the xenotime crystal structure. The molecular formula is Y a PO 4 where a ranges from 1.000 to 1.005. Preferably, the amount of yttrium present does not exceed 0.25 mole percent excess Y based on the formula YPO 4 . The particles of the yttrium phosphate formed are needle-like and appear in the form of soft clumps of interwoven strands of fine crystals. The clumps can be easily spread apart to form nanosize particles. The nature and objects of the invention are further illustrated by the following examples, which are provided for illustrative purposes only and not to limit the invention as defined by the claims. The examples show the effect of using mineral acid to dissolve excess yttrium oxide and form pure phase-yttrium phosphate. FIG. 1 , i.e., XRD pattern of sample DW-15-127-1, illustrates the solid material, predominantly yttrium phosphate, with minor amounts of yttrium oxide present. The sample was obtained from an in-progress test after phosphoric acid addition, then filtered, washed and dried at 1,000° C. FIG. 2 , i.e., XRD pattern DW-15-127-3, shows the transformation from material as shown in DW-15-1276-1 to single phase yttrium phosphate after reaction with mineral acid, washing and drying to 1,000° C. FIGS. 3 and 4 are images of Thermogravametric (TGA) and Differential Scanning Calorimetry tests performed on the same samples as FIGS. 1 and 2 . FIGS. 3 and 4 confirm phase purity due to the absence of further phase transformations. Although the invention has been described in detail for the purpose of illustration, it is understood that such detail is solely for that purpose and variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention which is defined by the following claims.

Methods for producing substantially single phase yttrium phosphate which exhibits the xenotime crystal structure are disclosed. The methods can be practiced without the use of high temperatures (e.g., the methods can be practiced at temperatures less than 1000° C.). The resulting yttrium phosphate can be in the form of particles which comprise interwoven strands of crystals of yttrium phosphate and/or nanoparticles prepared from such particles.

This application is entitled to the benefit of, and incorporates by reference essential subject matter disclosed in PCT Application No. PCT/GB2010/052166 filed on Dec. 20, 2010, which claims priority to Great Britain Application No. 0922264.7 filed Dec. 21, 2009 and Great Britain Application No. 1015893.9 filed Sep. 22, 2010. This application is related to U.S. patent application Ser. No. 13/321,437 filed Feb. 2, 2012. BACKGROUND OF THE INVENTION 1. Technical Field This invention relates to flow heaters for heating liquids, e.g. water. 2. Background Information A number of methods are known to provide hot or boiling water for domestic consumption. Traditionally electric kettles or jugs are used to boil a quantity of water e.g. for making hot beverages. More recently products have been marketed which promise to deliver small quantities of hot water very quickly. Rather than heat a body of water in a batch, these are based on flow-heaters which heat water as it passes through a narrow passage with a thick film printed element on one side. However such technology has significant drawbacks. One of these is that there is a greater risk of the heating element overheating than with conventional batch heaters which limits the efficiency with which water can be heated. During boiling of water in a conventional kettle, the bulk of the water is at substantially the same temperature which gradually rises as heating progresses. Only the boundary layer close to the heated surface is significantly hotter. Heat is transferred from the heated surface to the boundary layer by conduction and initially at least, from the boundary layer to the bulk by convection. In heaters with a high surface temperature, the water in the boundary layer can reach 100° C. and boil while the bulk water is relatively cool. The bubbles of steam, initially condense and collapse due to contact with the cooler bulk water. As heating continues, bubbles of steam, being lighter than the surrounding water rise from the heater surface. As the bubbles rise they conduct heat to the cooler surrounding water and the resultant condensation eventually causes the bubble to collapse. However as the bulk of the water approaches boiling temperature, it no longer causes full condensation of the rising bubbles, and these rise to the surface and break free which is generally considered to indicate that the water is boiling. In practice the bulk water temperature will not quite be at 100° C. at this stage. Conventionally, domestic jugs and kettles will maintain a “rolling boil” for several seconds which enables the bulk water liquid to uniformly reach a temperature very close to 100° C., although it never quite gets there and moreover the actual boiling point is dependent on other factors such as atmospheric pressure and the presence of dissolved substances in the water. A flow heater, by comparison, has the benefit of being able to heat water on demand and to be operated only for as long as necessary to deliver the required quantity of water. However consumers expect a start-up time that appears virtually instantaneous—certainly no longer than a few seconds. In the context of small domestic products the amount of power is fixed by that available from the wall outlet socket (1500 W to 3000 W typically) and can't be increased. Under steady state conditions, the flow-rate of water will be matched to the heater output power according to the basic laws of thermodynamics (for a 3 kW heater, a flow-rate of around 0.5 liters/minute up to 1 liter/minute will provide water with a temperature range from near boiling down to about 65° C.). The heater type, and heat exchange mechanism have little influence. When designing a flow heater with very fast start-up it is important to minimize the thermal mass of the heater itself and the temperature to which it needs to be heated. It is also important to maximize the contact area between the water and the heater. These requirements have been addressed in the recent prior art by the use of a thick film heater bonded via an intermediate electrical insulation layer to a stainless steel heat exchanger. The heat exchanger is designed with a complex chamber facing the heater to maximize the contact area. However the Applicant has realized that care must be taken over the distribution of water flow over the heater surface. If any section of water in contact with the surface is allowed to stagnate, it will quickly boil, creating a pocket of steam. A pocket of steam will no longer provide cooling to the element surface. The effect of this is rapid localized heating of the surface, and a failure, usually of the insulation between the heater track and heater substrate surface. To avoid this, the water is therefore constrained to flow in a tortuous narrow channel to avoid stagnant spots. The Applicant has also appreciated that another problem arises with the use of a narrow water channel. As the water approaches the end of the heater, it will be at its hottest—e.g. 85° C. The water channel, although small, nevertheless still consists of a boundary layer and a bulk water channel; the water in the boundary layer will often boil, creating bubbles of steam. In this configuration, a bubble of steam, emerging into the very small channel is unable to transfer heat by conduction and condensation, as it cannot expose its surface area to surrounding water, instead, the expanding bubble will simply push the remaining water ahead of it. It can be seen, that if this bubble occurs, for example 80% of the way along the channel, it will in fact cause all of the water in the last 20% of the channel to be ejected violently. In addition to the undesirable effect of “spitting” from the users perspective, the depletion of water cover at the end sections of the heater can often lead to premature element failure. The problems of localized hot spots and spitting place a constraint on the degree to which flow heater design can be optimized to maximize the ratio between the heater surface area and the volume of liquid which is needed to minimize heating times. Furthermore the need to provide adequate sensing of the element temperature to guard against overheating also compromises the heater design. SUMMARY OF THE DISCLOSURE When viewed from a first aspect the present invention provides a flow heater comprising a heating element, a first heating region heated by said heating element for heating liquid flowing therethrough to a first temperature below boiling, and a second heating region for heating said liquid to a second temperature below boiling, said second region having means for permitting the exit of steam therefrom separately from heated liquid, wherein said flow heater cannot be operated so that bulk boiling of said liquid takes place in the second region. When viewed from a second aspect the invention provides a flow heater comprising a heated flow conduit for heating liquid therein to a first temperature below boiling and a final heating chamber for heating said liquid to a second temperature below boiling wherein said heating chamber comprises a space above the liquid surface for allowing the escape of steam from the liquid surface wherein said flow heater cannot be operated so that bulk boiling of said liquid takes place in the final heating chamber. In the context of the present application a flow heater is defined as one which is able to heat liquid while it flows through and out of the heater. It will be seen by those skilled in the art that in accordance with the invention a flow heater is provided with a second heating region or final heating chamber which allows steam to escape from the surface of the water without forcing the heated water out—i.e. the phenomenon of spitting is reduced or avoided. Moreover the facility for steam to escape allows the surface of the heater to remain flooded in water and so avoid localized hot spots. Even though the second heating region does not raise the bulk temperature of the liquid to boiling point, as explained above micro-boiling tends to take place at the heater surface leading to localized steam production as the bulk temperature increases. A standard flow heater can be thought of as one in which there exists in use a temperature gradient along the direction of flow. Whilst the invention allows heated water to be produced, only the water in the second region achieves the final temperature; it is not necessary to heat the whole of the contents of the heater to that temperature as would be the case with a kettle or other ‘batch’ heater. For example a cold water temperature of 20° C. preheated to 80° C. in the first region will have an average temperature of only 50° C. In accordance with the invention the second heating region or final heating chamber continues to heat the water from the temperature at which it leaves the first region (e.g. the first region resembling a traditional flow heater), to a higher temperature but not bulk boiling. A separate heater could be provided for this purpose. In a set of preferred embodiments however a single heater is provided which extends into the second heating region or final heating chamber. Hereinafter reference will only be made to the first heating region and second heating region respectively. However, these references should be understood to apply equally to the heated flow conduit and the final heating chamber respectively recited in accordance with the second aspect of the invention. The omission of these latter two terms is simply for reasons of brevity and no other conclusion should be drawn. The form of the transition between the first and second heating regions is not considered essential to the invention and several possibilities are envisaged. For example, the first heating region could gradually open out at its downstream end to form the second heating region. In such a case the point of transition between the first and second heating regions could be defined relatively arbitrarily. For example, the transition could be defined in terms of the dimensions of the channel through which the liquid being heated flows such as the point at which the cross section of this channel begins to expand, or when it has fully expanded or at the midway point. Alternatively, a definition in terms of the linear flow speed could be envisaged, e.g. where the linear flow speed is reduced to half the speed in the first region. Functionally the transition occurs when bubbles of steam can escape from a surface of the liquid without displacing the remaining liquid. In the first region, the controlled parameter is the water velocity (achieving a balance between good heat transfer with high velocity and acceptable hydraulic pressure drop) and in the second region the controlled parameter is water level, achieving a balance between heat transfer, by ensuring the heater is covered, and minimizing water volume by ensuring the water level is as low as possible. Minimizing water volume in the first and second regions maintains the fastest start-up time. In accordance with the second aspect of the invention the heated flow conduit could be heated in a number of ways. In one set of embodiments it is provided with an electric heating element for heating the liquid therein as in accordance with the first aspect of the invention. However this is not essential. It could alternatively for example be provided by one side of a heat exchanger, through the other side of which a hotter liquid or gas is passed. The heating element for the first region, or the heated flow conduit where this is provided with a heating element, could take any convenient form. In one set of embodiments, the heating element is provided on the outside of a channel or conduit forming the first heating region. The element could take the form of a so-called thick film printed element. Such elements are conventionally planar, but can also be produced with non-planar substrates. Alternatively it could comprise a sheathed resistance heating element, with or without an intermediate metallic heat diffuser plate as is commonly found in so-called underfloor heaters for domestic kettles. The advantages of having an element on the outside of the channel are that it is relatively easy to manufacture and it allows overheat protection to be provided in close thermal contact with the element to switch off the element in the event of it being energized without water in the channel. In another set of embodiments an immersion element is provided within a channel or conduit forming the first heating region. Accordingly, in preferred embodiments the first heating region comprises a channel for conveying liquid having a sheathed heating element disposed therein for heating the liquid. The element could be mounted to or in contact with a wall of the channel, although in a set of preferred embodiments it is disposed within the channel so that liquid is in contact with it all the way around its periphery. In a set of preferred embodiments, the first heating region comprises a preferably tubular jacket around the heating element such that liquid can flow between the element and the jacket. This is beneficial in giving a large surface contact area between the liquid and the heater surface, and also helps to minimize the tendency for spitting should any bubbles be formed since a single bubble cannot occupy the entire cross-section of the channel. Under normal operation, i.e. with bulk water temperature not exceeding 85 or 90° C., then a bubble forming will result in a higher water velocity in the remaining stream, improving heat transfer, and minimizing the likelihood of the bubble growing circumferentially. The jacket could conform in profile to the heating element (e.g. be of circular cross section if the heating element is of circular cross section) but this is not essential; it could be in the than of a block having a channel defined therein to accommodate the element and the liquid around it. Any suitable material could be used for the jacket. In one set of preferred embodiments, the jacket comprises stainless steel. This gives the overall heater robustness and in particular ensures that it is tolerant to overheating, for example by being operated without being in contact with liquid. The jacket should ideally have a low thermal mass and in the case of a stainless steel jacket this means that in preferred embodiments it should be relatively thin. Where a stainless steel or other metallic jacket is provided, it is preferably less than 0.7 mm thick, more preferably approximately 0.4-0.6 mm thick. The applicant has discovered, contrary to the prevailing wisdom in the art, that in fact a standard sheathed immersed element (e.g. of 6.6 mm diameter operating at 35 W/cm 2 ) with a thin stainless steel jacket as outlined above in fact has a lower thermal mass than a typical corresponding thick film heating element arrangement. Preferably the heating element has a circular cross-section. Preferably the channel or jacket (or at least the inner wall thereof) has a circular cross-section. Where the heating element cross-section is non-circular, the cross-section of the jacket or channel (or at least the inner wall thereof) is preferably the same shape. It is important to be able to exercise suitable control over the operation of flow heaters in accordance with the invention. One aspect of this is preventing serious overheating of the heater when it is accidentally operated without liquid. There are of course a number of ways in which this could be done. Advantageously the overheat protection is provided in the second region. This addresses a fundamental problem with providing dry-switch-on overheat protection in a flow heater comprising a sheathed heating element disposed in a channel and surrounded by liquid; the presence of the channel physically prevents placing a sensor in good thermal contact with the element. In a particularly convenient embodiment, a sheathed immersed heating element is employed, part of which is bonded to a metal “head” plate to form a hot return in exactly the same way as is well known for traditional immersed kettle elements. The advantage of this is that it then allows a conventional control for immersed elements, such as the applicant's extremely popular and successful R7 series of controls, to be used for giving both primary and secondary overheat protection for the element. Details of such controls are given in GB-A-2181598. Further preferably, such a control is also used to provide electrical contact to the element either directly or indirectly. The thermal sensor could, for example, be a thermistor, thermocouple or other electronic sensor or could be a thermo-mechanical sensor such as a shape-memory metal actuator or a bimetallic actuator. It could be in direct physical contact but preferably the good thermal contact is achieved via a thermally conductive wall of the second region—e.g. the traditional head and hot return arrangement described above. Preferably the part of the element which is in good thermal contact with the thermal sensor is higher than the rest of the heated part of the element. Additionally or alternatively, it may be desirable to measure the temperature of the liquid in or exiting from the heater. This could, for example, assist in overheat detection or it could be used as part of a feedback control system to control the flow-rate of water passing through the heater. When heated water is required it is advantageous to be able to exercise control over the flow rate since the optimum flow rate is determined by the precise power of the heater, the performance of any pump provided, the supply voltage and the incoming ambient water temperature. The first two of these factors are subject to manufacturing tolerances whilst the latter two can vary during use. In one set of preferred embodiments, means are provided for controlling the temperature of liquid supplied by the heater. The Applicant has appreciated that the output temperature of the liquid is a function both of the power of the heater and of the flow rate. Accordingly, either of these two parameters could be varied. In a set of embodiments, the means for controlling the temperature comprises means for altering the flow rate of liquid through the heater. For example, for a typical 3 kilowatt heating element, the Applicant has discovered that water can be supplied at approximately 90° C. (assuming it starts at approximately 17° C.) if the flow rate through the heater is approximately 590 ml per minute. If the flow rate is increased to 1000 ml per minute, the water is supplied at a temperature of approximately 60° C. The initiation of liquid flow (e.g. through activation of a pump or opening of a valve) could take place as soon as the heating element is energized. However in preferred embodiments the heater is arranged to initiate water flow after a delay interval relative to energization of the heating element. The Applicant has appreciated that by introducing a deliberate delay it can be ensured that substantially all of the liquid is dispensed at the desired temperature—i.e. there is no initial slug of cooler liquid at the beginning of the dispense operation. The delay could be fixed but is preferably determined as a function of the temperature of the liquid sitting in the heater so that if the liquid in the heater is warm, the delay is reduced, potentially down to zero (no delay) or even negative—i.e. the pump may be started before the heater if, for example, the system is being restarted after a short ‘off’ time and a lower desired temperature has been chosen. Similarly the flow could be switched off simultaneously with the heating element, but in a set of preferred embodiments the heating element is switched off before the flow is stopped. This allows the heat stored in the element and other components to be partly recovered to heat water. This is not only more energy efficient, but means that the heater can be used more quickly thereafter to dispense cooler liquid. The length of time for which liquid is dispensed could be fixed or indefinite—e.g. for as long as a user holds down a button. In a set of preferred embodiments liquid is dispensed for a time preset by a user. The time could be set directly, but preferably it is set by means of a dispensed volume control, in which case the dispense time will also be a function of the flow rate, which might in turn be a function of the dispense temperature as explained above. Having the liquid being dispensed for a predetermined time is beneficial in allowing the heating element to be turned down or off towards the end of the dispense operation to recover stored heat as outlined above. The Applicant has appreciated that where the temperature to which liquid is heated increases, it is very difficult to measure its temperature accurately since the liquid in the second region will be moving turbulently and may contain many bubbles of steam, so that any point temperature sensor such as a thermistor tends to give inaccurate and wildly fluctuating results. However, the Applicant has devised an arrangement which allows much more accurate and stable determination of the output temperature of the liquid. According to preferred embodiments of the invention, temperature sensing means are provided in the first heating region for determining the output temperature of a liquid. Thus, in accordance with these embodiments a temperature measurement of the liquid is made upstream of where it is finally dispensed, rather than measuring the actual output temperature of the liquid. This stems from the applicant's realization that there is a strong correlation between the temperature of the liquid at a known point in the first heating region and the output temperature. Given that both the liquid capacity and the heating power of the heating element downstream of the measuring point are known, the output temperature can be calculated. The advantage of measuring the temperature in the first region is that since the liquid is less turbulent in that region, a much more accurate temperature measurement can be made. Accurate knowledge of the temperature of the water in the second region (e.g. obtained through measuring temperature in the first region) is beneficial in allowing control of the apparatus in a number of ways. Firstly of course it allows the output temperature of the water to be varied. However, it also allows account to be taken of non-equilibrium situations arising from previous operations of the apparatus. For example, if the apparatus is being used to dispense hot water and a subsequent demand for cooler water is made by a user, the flow of liquid may be commenced earlier relative to energization of the heater, or it may even not be necessary to energize the heater at all depending on how much the liquid has cooled. Where temperature is measured in the first region the Applicant has realized that it is desirable in some circumstances to encourage a swirling flow component about the longitudinal axis of the channel or conduit since this ensures a more reliable single-point temperature measurement. Being able to measure temperature is preferable to requiring multiple sensors on cost grounds. In one set of embodiments the channel or conduit comprising the first region comprises an inlet arranged so as to introduce liquid thereto along a direction offset from the central axis of the channel or conduit in order to give the desired swirling which promotes mixing of the liquid inside the channel and hence a more even temperature distribution. For example the inlet could be arranged to introduce the liquid with a tangential component of flow. In another, not mutually exclusive, set of embodiments the channel or conduit in the first region is configured to promote a swirling flow. There are many possible ways in which this could be achieved. In a subset of such embodiments the internal surface of one or more of walls of the channel is/are provided with helical features. For example the surface could be provided with ribs, grooves, or any other patterns of protrusions or depressions which encourages swirling flow. The features could extend either part-way or all the way around the perimeter of the internal surface and could extend all or part-way along the length of the channel. The features need not be continuous; they could comprise a series of bumps or other protrusions. Where the channel is provided with an immersed element inside the channel, the helical features could be provided additionally or instead on the outer surface of the element. Another alternative, again not mutually exclusive with the options given above, is for an independent flow shaping element to be introduced into the channel. In a particularly convenient set of embodiments such a flow shaping element comprises a wire wrapped around a sheathed heating element immersed in the channel. This is not only economical to produce but is also relatively straightforward to assemble. A similar alternative might comprise a resilient coil wrapped around the element while it is inserted during manufacture and subsequently released so as to expand against the inner surface of the channel wall. In some embodiments the thickness of the wire is significantly less than, e.g. no more than 50% of, the width of the gap between the element surface and the channel wall; in other words the wire does not define separate individual helical channels but rather it simply encourages a swirling flow by causing a swirling motion of the boundary layer of liquid. In some such embodiments the thickness of the wire is less than a third of the width of the gap. In other embodiments the width of the wire is greater than 50% of the width of the gap—e.g. approximately equal to the width of the gap so that the wire defines separate individual helical channels through which the water flows. The flow shaping means—e.g. the aforementioned flow shaping element—could extend along the full length of the conduit, but in a preferred set of embodiments it extends only part-way along the length of the conduit. Further preferably an end of the flow shaping means is axially offset from the outlet of the channel or conduit. This has been found to be advantageous since the structure of the flow shaping means in the channel or conduit itself causes localized linear variations in the pressure and flow of the liquid through the channel or conduit, particularly where it occupies more than 50% of the cross-sectional flow area of the channel, since the flow tends to concentrate along the ‘leading edge’ of the flow shaping means. This can lead to variations in the sensed temperature of the liquid. Having the end of the flow shaping means offset from the outlet of the channel or conduit allows the swirling liquid to mix together sufficiently that at the point of the temperature measurement (typically in the vicinity of the outlet from the channel or conduit), any variation in temperature that was present in the liquid owing to the flow shaping means is reduced. This is considered to be novel and inventive in its own right, not just in the embodiments described above and therefore from a further aspect the present invention provides a flow heater comprising a channel for conveying liquid, said channel having an inlet and an outlet, and a heating element disposed in or on the channel, wherein the channel comprises flow shaping means having an end axially offset from said outlet so as to extend only part-way along the length of the channel. Preferably the flow shaping means is configured to introduce a swirling motion to liquid in the channel. The flow shaping means could comprise a flow shaping element introduced into the channel but this is not essential. As described above it could comprise features such as ribs, grooves etc. on the wall of the channel or, where provided, a sheathed element disposed in the channel. The end of the flow shaping means could also be offset from the inlet to the channel or conduit. This reflects the Applicant's appreciation that it is not normally necessary to introduce swirl for the first section of flow if temperature is not being measured until the end. This simplifies assembly and further reduces material costs. In one set of embodiments the end of the flow shaping means is offset from the outlet by a distance which is greater than the diameter (or, equivalently, the minimum cross-sectional dimension) of the channel or conduit, e.g. greater than twice the diameter, e.g. greater than three times the diameter. This allows the liquid to become well mixed to minimize any temperature variations before it reaches the vicinity of the outlet from the channel or conduit where the temperature is typically measured. Furthermore, by having the flow shaping means offset say 30% of the length of the channel or conduit from the outlet, the bulk water temperature in the location of the flow shaping means will not be close to boil, therefore, even in spite of the risk of localized stagnation or vortices, the risk of inadvertent localized boiling is reduced. Preferably the flow shaping means has a helical configuration. In one set of embodiments the helical configuration comprises a plurality of turns whereby, for at least part of its length, the distance between adjacent turns decreases away from the end closest to the inlet. The benefit of this arrangement is that the liquid flowing from the inlet initially experiences the gentler gradient of the flow shaping means, thereby minimizing turbulence, but as the gradient of the helical flow shaping means increases, a rapid rotation and therefore mixing of the liquid is achieved which allows reliable temperature measurement of liquid which has exited the flow shaping means. This is considered to be novel and inventive in its own right and therefore from a further aspect the present invention provides a flow heater comprising a channel for conveying liquid, said channel having an inlet and an outlet, and a heating element disposed in or on the channel, wherein the channel comprises flow shaping means having a helical configuration comprising a plurality of turns whereby, for at least part of its length, the distance between adjacent turns decreases away from the end closest to the inlet. In accordance with all aspects of the invention, the liquid flow could be driven by hydrostatic pressure achieved by arranging a reservoir of liquid above the outlet and using a valve or tap. Preferably, however, a pump is provided for driving liquid through the flow heater. In a set of preferred embodiments of the first aspect of the invention the first region comprises a pair of channels fluidically in parallel with one another, both communicating with the second region. By arranging for these channels to be at least approximately physically parallel too, the overall size of the heater assembly can be reduced for a given aggregate fluid path length which gives greater freedom when producing an acceptable industrial design. Separate heating elements may be provided for the respective channels but preferably a single common element is provided. Advantageously this comprises a sheathed heating element formed into an approximate U shape so that each arm thereof is disposed in a respective one of the channels and the curved section or sections is/are provided in the second region. The Applicant has recognized that in such an arrangement it is important to ensure that the flow in each channel is adequately balanced to prevent overheating of one portion of the element relative to the other. It has further devised several ways of achieving this as will be explained below. The heater could comprise a pump for each of the channels, each with an independent flow rate feedback control circuit, but in a preferred set of embodiments the heater comprises a common pump supplying both channels since this reduces cost and complexity. The Applicant has realized that in such arrangements there is the possibility of the flow being imbalanced between the two channels in some circumstances. This could be, for example, that the heating element tube is slightly off-center in one channel (if such an arrangement is used) compared to the other, there is an uneven build-up of scale, or a steam bubble is created. The Applicant has recognized that if factors affecting the channels' flow resistances unequally are allowed to have significant impact on the corresponding flow rates, then control could be lost over the temperature of the heater, with the serious risk of overheating. However it has further recognized that if the overall heater system is configured such that the heated channels represent a minor proportion of the overall pressure drop in the system, the impact of such unequal factors can be reduced. Therefore in one set of embodiments the heater system comprises means upstream of the heated flow channels for restricting the flow of liquid thereto such that in use the pressure drop across the flow restricting means is greater than 50% of the total pressure drop from the pump to the outlets of the channels. This is considered to be novel and inventive in its own right and therefore when viewed from a further aspect the present invention provides apparatus for heating liquid comprising: two heated flow channels each comprising heating means for heating liquid flowing therethrough and each channel having an inlet and an outlet; a common pump for supplying liquid to the heated flow channels, and means upstream of the heated flow channels for restricting the flow of liquid thereto such that in use the pressure drop across the flow restricting means is greater than 50% of the total pressure drop from the pump to the outlets of the channels. Said total pressure drop may be equivalent to a head of water greater than 500 mm. It will thus be appreciated that, as explained above, the means for restricting the flow into the two heated flow channels helps to minimize the effect of imbalance between the resistances of the two heated flow channels, and therefore provides some protection for the heating means against overheating. A common flow restriction means could be provided for the two channels, but in some preferred embodiments individual restrictors are provided for each channel. By trimming the resistance of each such restrictor—e.g. at the factory—any minor imbalance between their flow resistances arising through manufacture can be compensated. The means for restricting the flow could simply be provided by the molded or machined shape of tubes, manifolds etc. but conveniently separate restricted bore components are used. This option provides flexibility to trim the flow resistances as mentioned above—either by trimming the length of the component and/or by selecting from a range of components of differing bores. In one set of embodiments the pressure drop across the means for restricting the flow is greater than 75% of the total pressure drop, e.g. greater than 85%, e.g. greater than 90%. As will be appreciated, the higher the pressure drop across the restriction means, the less significant the effect of any imbalance between the flow resistances of the heated flow channels, and therefore the greater the improvement in reliability which can be achieved. However this comes at the price of having to provide a higher power pump to provide the design flow rate through the artificially increased flow resistance. In a set of embodiments offering another (not mutually exclusive) way to address flow resistance imbalance between the channels, each of the parallel channels is provided with flow regulating means configured to offer a flow resistance dependent on flow rate through the corresponding channel so that as flow rate in the channel increases, e.g. as the result of a blockage reducing flow in the other channel, the flow resistance of the flow regulating means increases to compensate. Although this will lead to an overall reduction in aggregate flow rate through the two channels, this is preferable to the flow rates in the channels being out of balance. An overall reduction in flow rate can, for example, be compensated by increasing the speed of the pump. This is considered to be novel and inventive in its own right and therefore from a further aspect the present invention provides a flow heater comprising at least two fluidically parallel channels, wherein each channel comprises: a heating element disposed on or in the channel to heat liquid flowing therethrough; and flow regulating means configured to offer a flow resistance dependent on flow rate through the corresponding channel so that as flow rate in the channel increases the flow resistance provided by the flow regulating means increases. The flow regulating means could take a number of different forms, some of which may be known per se in the art. However in a particularly convenient set of embodiments it has been found that such an effect can be achieved using a helically configured flow shaping element of the type discussed above for introducing swirl into the flow in the channels, by forming it of resilient material. This is because as the flow rate increases it tends to force the element to contract against its resilience, reducing the separation of adjacent turns. This gives a smaller effective section for the helical path which the liquid is encouraged (or forced) to follow, thereby increasing the flow resistance. Although not essential, typically such a flow shaping element would be provided outwardly of a sheathed heating element disposed in the channel—i.e. between the element and the inner wall of the channel. The flow shaping element is preferably fixed at its downstream end—e.g. to the wall of the channel or the element if that is provided in the channel, and allowed to move at the upstream end (to permit the required contraction). It will be appreciated that by employing such flow regulating means, a degree of self-regulation and thus balance between the flow in the two channels can be achieved. Whilst this feature can beneficially be employed in conjunction with the flow restricting means discussed earlier, it may allow for the resistance of the flow restrictions means to be reduced as compared to its value without such self-regulation. In a set of embodiments offering yet another (not mutually exclusive) way to address flow resistance imbalance between the channels, the apparatus comprises two inlet channels for supplying liquid from the pump to the two heated flow channels, wherein the two inlet channels comprise means for increasing the flow resistance in one inlet channel in response to the pressure in the other inlet channel increasing. Thus it will be appreciated that when the pressure in one of the heated flow channels and therefore its associated inlet channel increases, e.g. as the result of a blockage reducing flow in the heated flow channel, the resistance in the other inlet channel is increased to balance out the pressure between the two inlet channels and so the flow rate through the heated flow channels. Again, although this will lead to an overall reduction in aggregate flow rate through the two heated flow channels, this is preferable to the flow rates in the channels being out of balance. An overall reduction in flow rate can, for example, be compensated by increasing the speed of the pump. This is considered to be novel and inventive in its own right and therefore from a further aspect the present invention provides an apparatus for heating liquid comprising: two heated flow channels each comprising heating means for heating liquid flowing therethrough and each channel having an inlet and an outlet; a common pump for supplying liquid to the heated flow channels, and two inlet channels for supplying liquid from the pump to the two heated flow channels, wherein the two inlet channels comprise means for increasing the flow resistance in one inlet channel in response to the pressure in the other inlet channel increasing. It will also be appreciated that the means for increasing the flow resistance in one inlet channel could replace the previously recited means for regulating or restricting the flow, and in this set of embodiments it therefore allows a lower power pump to be used as the resistance provided by the flow regulating or flow restricting means does not have to be overcome, it is simply the variable flow resistance which balances the flow. However the Applicant has realized that it could be advantageous to use flow regulating or flow restricting means in combination with the means for increasing the flow resistance in one inlet channel and a higher pressure pump as this can give a more instantaneous response to any variations in flow through the channels. The means for altering the resistance in one inlet channel in response to the pressure in the other inlet channel could comprise a mechanical coupling between two separate inlet channels, e.g. a fluid or gel filled region, struts, ribs, or other couplings between flexible or displaceable walls. However, in a preferred set of embodiments the inlet channels share a displaceable common wall for at least part of their length. Therefore when the pressure in one of the inlet channels increases, the common wall is displaced to increase the cross sectional flow area of that inlet channel and reduce the flow area in the other thereby balancing out the pressure between the two inlet channels and so the flow rate through the heated flow channels. The displaceable common wall could simply comprise a flexible or sprung wall between the two inlet channels. However, in a preferred set of embodiments the common wall comprises a diaphragm in a distribution plenum block. Providing a diaphragm in a distribution plenum block gives a large common area between the two sides thereby giving fine control over the flow balance between the channels. The diaphragm could comprise biasing means to bias the diaphragm to its central position, e.g. a spring either side of the diaphragm, so that the elastic response of the diaphragm can be controlled. Except where stated otherwise, in accordance with all aspects of the invention the flow heater may be employed to produce boiling liquid—e.g. by heating liquid in the second region to boiling. Where not explicitly mentioned all aspects of the invention can be advantageously employed in a flow heater comprising a first heating region for heating liquid flowing therethrough to a first temperature below boiling, and a second heating region for heating said liquid further—either to boiling or to a second temperature below boiling, said second region having means for permitting the exit of steam therefrom separately from heated liquid. In all aspects of the invention the means for permitting the exit of steam therefrom separately from heated liquid is preferably configured to allow steam and heated liquid to exit their respective exit means simultaneously. There are many possible arrangements for dispensing the heated liquid from the second region in accordance with the invention. One possibility would be a simple valve or tap for allowing water to drain out of the second region/final heating chamber. The problem with such an arrangement is that the outflow through such a valve or tap would have to be precisely coordinated with the inflow from the pump. For example, if the outflow rate is even slightly greater than the inlet flow rate, (or if it commences to flow out too early) the heater will run dry. If the outflow rate is slightly lower, then the outflow chamber will overflow, or, as the water level increases, the effect of micro-boiling in the chamber will result in water spitting. This will occur because, as the steam bubbles generated at the surface now must travel through a vertical body of water, they will entrain droplets of water and carry them at high velocity to the surface. The pump inflow, as discussed can start and stop at irregular times, and, is constantly varying in response to all the input variables—desired outlet temperature, inlet water temperature, voltage fluctuations, and the natural oscillations that can occur in any closed loop control system. The difficulty in controlling the outflow is further exacerbated by the need, on start-up, to prevent outflow until such time as sufficient water has entered to fill the system to its intended working level. In a set of preferred embodiments therefore means are provided to permit automatic outflow of liquid upon the liquid reaching a predetermined level. This ensures that a certain amount of liquid is retained and can therefore ensure that a heater surface is covered sufficiently to prevent it overheating. Such a function could be achieved electronically or through use of a float but preferably a weir is provided such that liquid escapes over the weir and out of the second region/final heating chamber when the water level in the region/chamber exceeds a predetermined height (determined by the height of the weir). In a set of embodiments a weir is provided in the second region, the height of which varies around its perimeter. This can allow greater control of the outflow rate for a given height of liquid in the second region. In a set of embodiments an outlet is provided in the second region, the surface area of which increases with the height of liquid in the second region. This too can allow greater control of the outflow rate from the second region. In particular it can be configured to allow the liquid in the second region to maintain adequate coverage of the heating element across a range of inflow rates. It has been found that the two features outlined above can be achieved using an outlet having a mouth shaped to conform approximately to the shape of a portion of the heating element disposed in the second region—e.g. so that the mouth is an approximately fixed spacing from the element. In another set of embodiments a weir is provided across the outlet, the open surface area of which increases with the height of liquid in the second region. Preferably the outlet of the second region is arranged to allow liquid to drain therefrom to a level below a portion of the heating element in the second region when the inflow rate is below a predetermined threshold. This ensures that, should flow in the system slow dramatically or cease unexpectedly, the said portion of the element in the second region will overheat and trigger overheat protection before the part of the element in the first region overheats as a result of the low flow rate. In one set of embodiments this is achieved by configuring the surface area of the outlet, or weir across the outlet, to increase with the height of liquid in the second region. The increase in surface area with height could be linear or non-linear. In all embodiments of the invention the heated or boiling liquid exiting the heating chamber could be dispensed directly into a user's receptacle, e.g. through a spout, or could be conveyed to another part of an appliance for further treatment. In accordance with various aspects of the invention, steam is allowed to exit from the second region separately from the heated liquid. It could be directed to exit from a part of an appliance away from the user in normal use—e.g. it could be vented to the rear of the appliance. In other embodiments the steam could be captured and condensed in a suitable trap, drip tray or the like. This could be a special drip tray or, more conveniently, a drip tray beneath the spout could be used. In one set of embodiments the steam outlet is configured to direct steam from the second region into a receptacle placed to receive heated liquid dispensed from the apparatus. This has several benefits. First it enhances safety by avoiding the issuance of steam from another part of the appliance which may be unexpected by a user, whereas the user will be expecting hot fluids to issue from the spout; the steam as well as the water can be captured in the receptacle. Second, the steam may assist in limiting loss of heat from the heated liquid while it is being dispensed, thus delivering the liquid closer to the required temperature. Third, particularly in appliances or modes of operation intended to deliver water close to boiling, the sight of steam in the vicinity of the outlet gives a greater user perception that the water being delivered is boiling. In a convenient set of the embodiments mentioned above a steam path and a heated liquid path are provided by a coaxial tube arrangement extending into the second region. The mouth of the steam path tube would be disposed at a level in the second region above the expected maximum level of liquid and the mouth of the liquid tube would be below this level. This arrangement thus maintains the important distinct paths for heated liquid and steam/vapor which is the key to minimizing spitting. In some embodiments of the invention the steam path between the second region/final heating chamber and the atmosphere is sufficiently restricted to give rise to a pressure difference across it in use of between 0.1 and 1 bar, preferably between 0.2 bar and 0.5 bar. By allowing the second region/final heating chamber to become slightly pressurized in use as compared to the atmosphere, the boiling temperature of the water or other liquid is slightly increased which helps to raise the temperature of the liquid actually received in the user's receptacle. Where reference herein is made to ‘steam’ this should not be understood as implying that any significant or bulk boiling occurs; rather it is intended to indicate any vapor, damp air or steam proper which might arise. The orientation of the apparatus, and particularly the first region can be chosen to suit the form of the appliance in which the heater is employed. Conveniently in one set of embodiments the heated flow conduits in the first region are arranged to run horizontally, but in some embodiments the channels or heated flow conduits are arranged to run vertically, e.g. in a coffee maker to save space. BRIEF DESCRIPTION OF THE DRAWINGS Certain embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: FIG. 1 is a perspective view of a heated water dispensing apparatus embodying the invention; FIG. 2 is a partly cut-away view of the apparatus showing the main components thereof; FIG. 3 is a cross-sectional view through the water reservoir and other components; FIG. 4 is a horizontal cross-section through the water inlet distribution block and flow heater pipes; FIGS. 5 and 6 are perspective views of the flow heaters, heating chamber, control unit and a modified water distribution block; FIG. 7 is a close-up view of the modified water distribution block; FIG. 8 is a vertical section showing the interior of the modified water distribution block of FIG. 7 ; FIG. 9 is a vertical section showing the interior of one of the flow heaters; FIG. 10 is a vertical section showing the interior of the other flow heater; FIG. 11 is a dramatically enlarged cross-section through the heating tube; FIG. 12 is an exploded view of the element head and control unit from the front; FIG. 13 is an exploded view of the element head and control unit from the rear; FIG. 14 is a view of the heating chamber with the element head removed for clarity; FIG. 15 is a vertical section showing the interior of the heating chamber; FIGS. 16 and 17 are perspective views of the flow heaters, heating chamber, control unit and a water distribution block of another embodiment; and FIGS. 18 and 19 are vertical sections showing the interior of the heating chamber of FIGS. 16 and 17 . DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows an embodiment of the invention which can be used to dispense heated water, on demand into a cup 2 for making hot beverages. The temperature of the water can also be adjusted by turning a knob 4 . The dispense temperature can be varied, for example, from 65° C. to nearly 100° C. The amount of water to be dispensed is controlled by a second knob (not shown). On the upper part of the main part of the apparatus is a water tank 8 which must be filled periodically by a user. FIG. 2 shows some of the main internal components of the apparatus with other parts omitted for clarity. From here may be seen the water tank 8 , extending downwardly from which is an outlet pipe 10 connected to the inlet side of a pump 12 . The outlet side of the pump 12 is connected via a tube 14 to a water distribution plenum block 16 which distributes water entering the block between two parallel flow heater sections 18 , 20 together forming a first heating region, as will be explained in greater detail below with references to FIGS. 4 to 8 . At the downstream end of the flow heater portions 18 , 20 is a heating chamber 22 forming a second heating region. This is formed by a deep-drawn stainless steel cup 23 fitted to an approximately circular stainless steel element head 54 (see FIGS. 3 , 8 , 9 , 13 and 14 ). The heating chamber 22 has an outlet spout 24 projecting downwardly from it for dispensing heated water into the user's cup 2 . The cross-section of FIG. 3 shows the interior of the water tank 8 . From this it can be seen that the base of the water tank 8 has a circular aperture 26 which is designed to receive a water filter, for example the applicant's Aqua Optima water filter. This is represented very schematically by the component marked with the reference numeral 28 . The water filter 28 has a restricted outlet aperture (typically of the order of 4 mm) which has the additional benefit in the present context that it is too small to allow air to pass into the filter when there is water in the filter; were this not the case bubbles of air could get into the filter and reservoir so allowing the continuous flow of water. The lower part of the water filter 28 is received inside a further, intermediate holding chamber 30 , in the center of which is an outlet connected to the pipe 10 which connects it to the pump 12 . A vertical tube 32 extends from the upper part of the holding chamber 30 into the main water tank 8 and terminates just inside an indented portion 34 of the top of the water tank 8 . This allows pressure equalization between the holding chamber 30 and the water tank 8 . FIG. 4 shows a schematic of a horizontal cross section through the distribution plenum block 16 and the two parallel flow heaters 18 , 20 . The outlet side of the pump connects via a tube (not shown here) to a vertical inlet channel 36 in the distribution block 16 . This connects within the block to two laterally extending tubes 38 which open out into corresponding larger bore circular section cylindrical chambers 40 , 42 at right angles to the lateral tubes 38 . Disposed within each of the lateral tubes 38 is a ferrule 37 which has an external diameter equal to the internal diameter of the corresponding lateral tube 38 so as to form a tight interference fit. The internal diameters of the ferrules 37 are clearly narrower than the tubes 38 and so represent an intentional additional flow resistance. The inlet ends of the ferrules 37 may be flared. Because the ferrules 37 are separate components inserted during manufacture, it is possible to use ferrules having slightly differing flow resistances on either side in order to compensate for any inherent differences in flow resistance of the two flow heater tubes 18 , 20 which may have arisen during manufacture. The is most conveniently achieved by trimming the lengths of the individual ferrules to give the required flow resistance. The cylindrical chambers 40 , 42 receive the ends of the two flow heater sections 18 , 20 respectively. As can now be seen, each of the flow heater sections 18 , 20 comprises an outer jacket 44 , 46 and a length of a sheathed immersion-type heating element 48 which, although not depicted, comprises a stainless steel casing and a coiled resistance wire packed in magnesium oxide insulating powder. The cold tails 50 , 52 of the immersed element emerge through holes provided in the rear of the distribution plenum block 16 . The two flow heater sleeves 44 , 46 are wider in diameter than the corresponding heating element 48 and so define therebetween a corresponding annular channel for each of the flow heater sections 18 , 20 . As may be seen from this cross-section, the sleeves 44 , 46 make a sealing connection with the front end of the circular channels 40 , 42 in the block 16 but stop short in those channels of the point where they meet the lateral channels 38 so that the aforementioned annular channel in each of the flow heaters 18 , 20 is open to the cylindrical chambers 40 , 42 formed within the distribution block 16 whilst the sheathed element 48 extends through the block and is sealed against it. The result of this is that there is a fluid path from the block inlet 36 , via the lateral channels 38 , the ferrules 37 and the cylindrical chambers 40 , 42 to the interior annular channels of the two flow heaters 18 , 20 . FIGS. 5 and 6 show two different views of a slightly modified embodiment from that shown in FIGS. 1 to 4 , for which the majority of the components are the same. The main difference is that a differently shaped distribution plenum block 16 ′ which is provided between the inlet ends of the flow heaters 18 , 20 . In addition to the features shown in FIGS. 1 to 4 , a tube 41 extends from the lower surface of the heating chamber 22 adjacent to the outlet from one of the flow heaters 18 . Another tube 43 extends from the underside of the other flow heater 20 just before its outlet into the heating chamber 22 . Accommodated within each of these two tubes 41 , 43 is a thermistor (shown in FIGS. 8 and 9 ) which is positioned to sense the temperature of the water at the respective point of the flow heaters 18 , 20 . Also shown is a standard immersed element control unit 58 which is fixed to the other side of an immersed element head plate 54 from the heating chamber 22 . FIG. 7 shows a close-up view of the distribution plenum block 16 ′ which includes a different arrangement for the lateral tubes 38 ′ and the ferrules 37 ′ to that shown in FIG. 4 . The lateral tubes 38 ′, in which the ferrules 37 ′ are disposed, project outwards from the surface of the distribution plenum block 16 ′ on either side of it. A pipe (not shown) connects onto each of the lateral tubes 38 ′ to provide fluid connection to the outlet tube 14 from the pump 12 . FIG. 8 shows a vertical cross section through the distribution plenum block of FIG. 7 . Inside the distribution plenum bock 16 ′ the lateral tubes 38 ′ and their ferrules 37 ′ lead into the bottom of two circular section cylindrical chambers 140 , 142 which are separated by a diaphragm 100 . The diaphragm, made from a flexible material such as silicone rubber, comprises a rib at its circumference which is clamped between the two halves of the distribution plenum block 16 ′ such that it is stretched taught to create the two separate inlet chambers 140 , 142 . Each of the cylindrical chambers 140 , 142 connects within the distribution plenum block 16 ′ via two other lateral tubes 102 , 104 , to two other circular section cylindrical chambers 40 ′, 42 ′ at right angles to the lateral tubes 102 , 104 . The cylindrical chambers 40 ′, 42 ′ receive the ends of the two flow heater sections 18 , 20 respectively. The result of this is that there is a fluid path from the inlet lateral tubes 38 ′, the ferrules 37 ′, via the cylindrical chambers 140 , 142 , the other lateral tubes 102 , 104 and the other cylindrical chambers 40 ′, 42 ′ to the interior annular channels of the two flow heaters 18 , 20 . The diaphragm also comprises a widened central portion opposite the two lateral tubes 102 , 104 which lead out of the distribution plenum block 16 ′, which, in the event of a large increase in pressure in one of the two circular section cylindrical chambers 140 , 142 in distribution plenum block 16 ′, e.g. owing to a complete blockage in one of the two flow heaters 18 , 20 , will act to seal the mouth of the lateral tube 102 , 104 leading out of the other cylindrical chamber 140 , 142 . This is aided by the mouth of the lateral tubes 102 , 104 projecting slightly from the edge of the cylindrical chambers 140 , 142 . FIG. 9 shows the full length of the flow heaters 18 , 20 . From here it can be seen that the respective outer sleeves 44 , 46 thereof are sealed at the other end to the heating chamber 22 . The heating element 48 extends into the heating chamber 22 and is bent round to form two elongate arms which respectively foam part of the two flow heaters 18 , 20 . This is seen more clearly in FIGS. 11 and 13 . Also shown in FIG. 9 is the tube 41 extending from the lower surface of the heating chamber 22 adjacent to the outlet from one of the flow heaters 18 which houses a thermistor 45 . The thermistor 45 projects into the heating chamber 22 a small distance above its base. FIG. 10 shows a similar view to FIG. 9 but from the opposite side of the flow heaters 18 , 20 . This shows the other tube 43 extending from the underside of the other flow heater 20 just before its outlet into the heating chamber 22 in which a thermistor 47 is housed. The tip of the thermistor 47 sits level with the jacket 46 of the flow heater 20 . Shown in FIGS. 9 and 10 , as well as in an enlarged isolated view in FIG. 11 (and again in FIGS. 12 to 14 ) is a wire 96 which is wrapped around each of the two arms of the sheathed heating element 48 in a helical fashion. The wire 96 is designed to encourage swirling of the water inside the annular channels of the flow heater, and starts its helical winding about half way along each arm of the sheathed heating element 48 from the cold tails 50 , 52 . The turns of the wire 96 start with a shallow gradient with respect to the axis of the sheathed heating element and increase in gradient such that the distance between the turns of the wire 96 decreases with each turn. The helical winding of the wire 96 continues for three turns, which have a distance between them of approximately 3×d, 2×d and d respectively where d is the diameter of the flow heater sleeves 44 , 46 . The helical winding finishes at a distance of approximately 3×d from the outlet of the flow heaters 18 , 20 . The helical winding of the wire 96 is carried out during manufacture prior to insertion of the arms of the element 48 into the respective sleeves 44 , 46 (see e.g. FIGS. 9 and 10 ) to form the annular channels along which the water flows in use. The wire 96 is conveniently made from stainless steel having a diameter of for example 0.4 mm, although the material, dimensions and pitch of the wire may be chosen to suit the particular application. It will be noted from FIG. 11 , however, that in this particular embodiment at least, the wire 96 which is wrapped around the element 48 is wide enough very nearly to fill the annular channel formed between the element 48 and the outer sleeve 44 completely. In use the presence of the wire 96 has been found to encourage a swirling motion of water inside the respective channels which, as was explained above, gives a more even circumferential temperature distribution and so facilitates temperature measurements. The decreasing distance between the turns of the helical wire 96 is such that the gradient of the wire 96 with respect to the axis of the heating element 48 is not too great to cause a disruptive influence on the flow of water, but by the time the gradient increases at the end of the wire 96 , this creates the necessarily fast swirling motion of the water to adequately mix it to enable a reliable temperature measurement downstream of the wire. The wire 96 stops short of the end of the flow heaters 48 which allows the water to freely mix by the time it reaches the temperatures sensors 45 , 47 with out the sensed temperature being influenced by flow artefacts caused by the wire. The two helical wires 96 are spot-welded to the element tube 48 at their respective downstream ends so that the remainder of the coils are free to move longitudinally with respect to the element 48 . In use this provides a degree of self-regulation in the flow resistance of the tubes which is dependent on the transverse cross-sectional area of the helical path which the water is made to follow by the spring 96 . It will be appreciated that this cross-sectional area is dependent on the height of the overall annular space formed between the element 48 and the jackets 44 , 46 ; and by the distance between adjacent turns of the wire coil 96 . If a partial blockage should arise in one of the flow heater sections 18 , the flow rate in the other 20 , will rise as it represents an easier path out of the plenum 16 . However this will tend to compress the spring coil 96 in the second channel 20 , thereby increasing its flow resistance until equilibrium between the two channels 18 , 20 is restored. This comes at the price of reducing the aggregate flow rate through the apparatus but this is preferable to the flow rates in the two channels being unbalanced. The aggregate reductions can, within a certain range, be increased by increasing the pump speed. As can be seen from FIGS. 9 , 10 and 12 , the bent portion of the element 48 is brazed to an immersed element head plate 54 which closely resembles the element head plates seen in traditional immersed element kettles. This arrangement is known as a hot return and, as can be seen from FIG. 13 , the other side of the head plate 54 is formed with a semi-circular indentation 56 to receive the snap-acting bimetallic actuator 57 of a standard immersed element control unit 58 . FIG. 13 also shows a copper strip 60 extending from the hot return against which bears a nylon thermal fuse 59 (shown in FIG. 12 ) of the control unit 58 for providing secondary level overheat protection. Alternatively in nickel-plated copper immersed element heads, no copper strip is required as is also well known in the art. It will be appreciated by those skilled in the art looking at FIGS. 12 and 13 that the cold tails of the element 50 , 52 do not project through the element head 54 as would be conventional for an immersed kettle element, but rather they project through the distribution plenum block 16 (omitted for clarity in FIGS. 12 and 13 ). Instead, two dummy cold tail components 62 , 64 project through the element head 54 to make electrical contact with the control unit 58 and are in turn connected by means of flying leads (not shown) to the cold tails proper 50 , 52 . This allows a standard production control unit 58 to be employed without modification, which is a substantial cost saving as against having to design and produce a new dedicated control unit. The element head is provided with three mounting studs 66 for the control unit 58 . The interior of the heating chamber 22 is best seen from the view of FIG. 14 (which has the element head 54 removed) and FIG. 15 . From here it can be seen that the chamber 22 formed by the stainless steel cup 23 is broadly of a squat cylindrical shape although its internal volume is limited by the two dummy cold tails 62 , 64 , the bent portion of the heating element 48 and by a steam tube 25 which extends almost to the top of the heating chamber 22 and exits coaxially through the outlet spout 24 . The steam tube forms an outlet for steam and vapor from the chamber 22 separate from the outlet path for heated liquid. A bolt 66 also passes through the heating chamber 22 (and the steam tube 25 ) to affix the stainless steel cup 23 onto the element head 54 . The top of the outlet tube 24 a is not flat but is scalloped to accommodate the bent portion of the heating element 48 . As well as having the steam tube 25 passing through the middle of the outlet tube 24 , this restricts the flow of water out of the outlet tube 24 , thus ensuring that the heating element 48 remains adequately covered in water, so preventing overheating in normal use. The scalloped shape at the top of the outlet tube 24 a also prevents water emerging from the channels of the flow heaters 18 , 20 from flowing directly into the outlet tube 24 , thereby ensuring it is properly heated to the desired temperature. A third function of the shape of the top of the outlet tube 24 is that, by having its minimum towards the bottom of the heating chamber, below the level of the heating element 48 , the chamber 22 drains quickly if the water flow from the flow heaters 18 , 20 is suddenly reduced or stopped—owing, for example, to a blockage in the flow heaters 18 , 20 . This causes the exposed part of the heating element 48 in the heating chamber 22 to overheat which can quickly be sensed via the hot return, though the minimum level of the top of the outlet tube 24 is still high enough for some water to remain in the bottom of the heating chamber 22 to provide a reliable temperature measurement from the thermistors 45 , 47 . The diameters of the steam tube 25 and the outlet tube 24 are chosen such that the heating chamber 22 becomes slightly pressurized (e.g. to about 1 bar) during operation. This acts to pressurize the water output from the heating chamber if, for example, the heater is being used in an apparatus such as a drip coffee machine. Operation of the apparatus will now be described. First the user fills the water tank 8 with water by removing it, inverting it, removing the water filter 28 and filling from a tap. The filter 28 is then replaced, the tank re-inverted and then placed back on to the apparatus. The water immediately starts to be passed through the water filter 28 inside it at a rate determined by the restricted outlet from the water filter as is known. As water passes through the filter 28 it begins to fill the connecting pipe 10 and then the lower holding chamber 30 , displacing air through the ventilation tube 32 into the sealed head-space of the water tank 8 . When the water level in the holding chamber 30 reaches the bottom of the ventilation tube 32 , air can no longer be expelled from the chamber and so the flow of water stops. When the user wishes to dispense water he/she sets the required temperature on the first knob 4 and then turns the second knob (not shown) round from an ‘off’ position to the required volume. Initially the controlling circuit (not shown) activates the heating element 48 . After a delay of one or two seconds (depending on the temperature of the water already in the heater) the pump 12 is operated to pump water from the lower chamber 30 through the pipes 10 and 14 into the distribution plenum block 16 , 16 ′. In other embodiments the pump may be started before the heater. As water passes through the channels 38 in the plenum block, the flow is balanced between the left and right channel. The bore of ferrules 37 , 37 ′ in these channels 38 is chosen so that the pressure drop across the ferrules 37 , 37 ′ is much greater than for all the rest of the hydraulic system. This is very important in maintaining correct flow through the downstream annular channels 18 , 20 . For example, if a minor restriction arises in one channel 18 , 20 but not the other, there is little effect on the flow rate, as the dominant pressure drop is through the ferrules 37 , 37 ′. A pressure drop ratio of say 10:1 gives the required effect. For example if the pressure drop across the tubular heaters 18 , 20 is equivalent to a 100 mm head of water, the pressure drop across the plenum channels 38 would be equivalent to a 1000 mm head. In the embodiment shown in FIGS. 5 to 15 , further balancing of the flow is regulated by the diaphragm 100 which is displaced from the center of the distribution plenum block 16 ′. Displacement of the diaphragm 100 acts to reduce the cross sectional flow area through one side of the distribution plenum block 16 ′, while increasing the cross sectional flow area through the other side, thereby increasing the flow rate on the side in which the flow rate has decreased, e.g. owing to a blockage, and balancing it by a decrease in the flow rate on the other side. Once water has been pumped into the distribution block 16 , 16 ′, it is pumped through this and down the annular channels of each of the two flow heaters 18 , between the heating element 48 and the corresponding stainless steel outer jacket 44 , 46 . This heats the water rapidly as it passes through from ambient temperature (of the order of 20° C.) in the distribution block 16 , 16 ′ to between 50° C. and 80° C. at the downstream ends of the flow heaters 18 , 20 , depending on the desired temperature of the water at the outlet tube 24 , which can be selected to be between 65° C. and nearly 100° C. The wire 96 arranged in a helical fashion in each of the flow heaters 18 , 20 acts to swirl the water as it passes along the annular channels. The wire 96 stops short of the end of the annular channels allowing the swirling water to mix well before its temperature is measured in the vicinity of the ends of the flow heaters 18 , 20 , as it has been found that the presence of the wire can introduce spatial deviations in temperature as discussed above. The temperature of the water is monitored by the thermistors 45 , 47 projecting into the tubes 41 , 43 in the side of one of the flow heaters 18 near the heating chamber 22 and into the heating chamber 22 at the outlet to the other flow heater 20 respectively. The temperature can be monitored accurately and reliably here since the water is not boiling and therefore there is no significant amount of steam bubbles within it, and also because the helical wire 96 is no longer present which allows the swirling water to mix and equalize any temperature differences. Having the two thermistors 45 , 47 at slightly different points on either of the flow heaters 18 , 20 gives two independent measurements of the temperature of the water allowing a more accurate determination of what the final outlet water temperature is predicted to be. Any changes in the measured temperature can be used by the control circuit to alter the speed of the pump 12 in order to correspondingly create a relatively constant temperature of water output from the flow heaters 18 , 20 , i.e. the pump speed is increased to decrease the temperature of the water and vice versa. The water then passes out of the flow heaters 18 , 20 and into the interior of the heating chamber 22 where it begins to fill this chamber, thereby covering (during normal operating conditions) the curved portion of the element 48 which projects into the heating chamber 22 . The curved part of the heating element 48 continues to heat the water in the heating chamber 22 . Any steam produced from micro-boiling during heating of the water in the heating chamber 22 can easily escape by means of the steam tube 25 which opens at the top of it. The steam passes through the steam tube and to a convenient outlet, though as it runs coaxially through the water outlet tube 24 it advantageously helps to keep the heated water warm as it passes from the heating chamber 22 into the user's cup 2 . Referring particularly to FIGS. 14 and 15 , it can be seen that as the water level in the heating chamber 22 rises level with and above the lowest part of the top of the outlet tube 24 , it will start to pour out through the aperture and through the outlet tube 24 and into the user's cup 2 . The pumped flow rate and the power of the element 48 are matched such that by the time the water leaves the heating chamber through the aperture and outlet tube 24 it is at the required temperature. The height and scalloped shape of the top of the outlet tube 24 a is chosen to ensure that the element 48 remains covered in water during normal flow rate but quickly drains the heating chamber 22 if the flow rate drops in order to quickly trigger the snap-acting bimetallic actuator 57 . Heated water continues to be dispensed until the volume set by the user has been dispensed. At which point the pump 12 is switched off. To increase the energy efficiency of the device, the heating element 48 is turned off about 2 seconds before the pump is turned off. There is sufficient stored energy in the element and other components to ensure that the water continues to be heated. If the water tank 8 should run dry, the heating element 48 will begin to overheat. However, this can be sensed by the temperature sensors 45 , 47 projecting through the tubes 41 , 43 into one of the flow heaters 18 and into the heating chamber 22 , just by the outlet to the other flow heater 20 , respectively. As a backup the bimetallic actuator on the control unit 58 will sense overheating of the element 48 and therefore snap into its reverse curvature thereby opening a set of contacts in the control unit in the well-known manner. Secondary backup protection is provided by the thermal fuse 59 of the control unit 58 , again as is very well known in the art. The heating element 48 is arranged to ensure that in the case of dry boil or dry switch-on, the hot return portion brazed to the head 54 is the first to become dry. This is achieved by ensuring that the flow in the dual tubes 18 , 20 of the first heater is balanced under all adverse conditions (as explained earlier) and also by ensuring that the hot return is slightly higher than the rest of the element 48 by having it and the surrounding tubes 18 , 20 slightly inclined. This has a further benefit, on start-up from dry, of ensuring that the tubes 18 , 20 are free venting, and that the flowing water can easily push the initial volume of air ahead of it and out into the boil chamber 22 without airlock. Should the user wish to dispense water at a different temperature, he or she can use the knob 4 at the top of the appliance to set the required temperature which will cause the pump 12 to operate at a higher or lower speed (depending on whether a lower or higher temperature respective has been selected) and therefore give a higher or lower flow rate of water respectively through the apparatus which will mean that it is heated to a lower or higher temperature respectively before it is dispensed. The temperature sensors 45 , 47 projecting into the tubes 41 , 43 allow the temperature of the water being dispensed through the outlet spout 24 to be predicted from a knowledge of the proportion of the heating element 48 which is upstream of it and the corresponding proportion of the heating element 48 which is downstream of it—i.e. the curved portion in the heating chamber. The sensors can also be used to introduce a relative delay between operating the pump and switching on the element 48 depending upon the ambient temperature of the water sitting in the apparatus (e.g. as a result of previous operation) taking into account the temperature of water requested by the user. Thus it will be seen that the embodiment described above provides the benefit of a flow heater, i.e. being able to dispense a controllable volume of water on demand, but with the significant advantage of being able to easily sense overheating of the heating element 48 via the hot return through the element head 54 and therefore provide a safe and reliable apparatus. The heating chamber and the separation of the steam through the steam tube 25 from the water outlet 24 gives another advantage in that water can be dispensed without spitting and localized hot spots on the heating element from micro-boiling. FIGS. 16 to 19 show different views of a slightly different embodiment to that shown in FIGS. 5 to 15 , for which the majority of the components are the same. The main difference is that the flow heaters 218 , 220 run vertically between the distribution plenum block 216 and the heating chamber 222 . The distribution plenum block 216 has two horizontal inlets 238 to either side of a diaphragm therein (not shown but arranged as shown in FIG. 8 ). The flow heaters 218 , 220 exit the distribution plenum block 216 vertically and enter the heating chamber 222 at their opposite ends. The heating chamber 222 is rotated through 90 degrees compared to the heating chamber shown in the embodiment of FIGS. 5 to 15 . Also shown is a standard immersed element control unit 258 which is fixed to the other side of an immersed element head plate 254 from the heating chamber 222 . In this embodiment the outlet spout 224 exits the heating chamber 222 horizontally, and has a steam tube 225 coaxial within it. The interior of the heating chamber 222 is best seen from the view of FIGS. 18 and 19 . From here it can be seen that the chamber 222 formed by the stainless steel cup 223 is broadly of a squat cylindrical shape although its internal volume is limited by the bent portion of the heating element 248 . The water outlet tube 224 exits from an upper part of the heating chamber 222 , and has its lower portion covered by a weir 226 . The steam outlet tube 225 has its mouth at the top of and within the water outlet tube 224 . A thermistor 245 projects through the base of the heating chamber 222 and has its tip at the level of the bottom of the weir 226 . The weir 226 has a wider cross section in its upper portion and a narrower cross section (a slit) in its lower portion. This restricts the flow of water into the outlet tube 224 thus ensuring that the heating element 248 remains adequately covered in water, so preventing overheating in normal use. A second function of the shape of the weir 226 is that, by having a smaller cross section in its lower portion, at the level of the bottom of the heating element 248 , the heating chamber 222 drains quickly if the water flow from the flow heaters 218 , 220 is suddenly reduced or stopped—owing, for example, to a blockage in the flow heaters 218 , 220 . This causes the highest part of the heating element 248 to overheat which can quickly be sensed via the hot return, though the minimum level of the top of the outlet tube 224 is still high enough for some water to remain in the bottom of the heating chamber 222 to provide a reliable temperature measurement from the thermistor 245 . As in the previous embodiment, the cross sectional area of the mouths of the steam tube 225 and the outlet tube 224 are chosen such that the heating chamber 222 becomes slightly pressurized (e.g. to about 1 bar) during operation. Operation of the embodiment of the apparatus shown in FIGS. 16 to 19 is very similar to that described for the previous embodiments. The main difference is the effect of the weir in the heating chamber 222 . When water begins to fill the heating chamber 222 after passing out of the flow heaters 218 , 220 , the curved portion of the heating element 248 is covered during normal operating conditions. The temperature of the water in the heating chamber 222 is monitored by the thermistor 245 which projects into the heating chamber 222 near the outlet 224 . The curved part of the heating element 248 continues to heat the water in the heating chamber 222 . Any steam produced from micro-boiling during heating of the water in the heating chamber 222 can easily escape by means of the steam tube 225 which opens at the top of it. The steam passes through the steam tube 225 and to a convenient outlet, though as it runs coaxially through the water outlet tube 224 it advantageously helps to keep the heated water warm as it passes from the heating chamber 222 into the user's cup. Referring particularly to FIGS. 18 and 19 , it can be seen that as the water level in the heating chamber 222 rises level with and above the lowest part of the weir 226 , it will start to pour out over the weir 226 and through the outlet tube 224 and into the user's cup. The pumped flow rate and the power of the element 248 are matched such that by the time the water leaves the heating chamber overt the weir 226 and through the outlet tube 224 it is at the required temperature. The height and shape of the weir 226 is chosen to ensure that the element 248 remains covered in water during normal flow rate but quickly drains the heating chamber 222 if the flow rate drops in order to quickly trigger a snap-acting bimetallic actuator connected to the other side of the hot return (not shown in this embodiment). As in the previous embodiment, the heating chamber and the separation of the steam through the steam tube 225 from the water outlet 224 gives the advantage that water can be dispensed without spitting and localized hot spots on the heating element from micro-boiling. Although this invention has been shown and described with respect to the 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.

A flow heater comprises a heating element ( 48; 248 ) and a first heating region ( 18, 20; 218, 220 ) heated by the heating element ( 48; 248 ) for heating liquid flowing therethrough to a first temperature below boiling. The flow heater also comprises a second heating region ( 22; 222 ) for heating the liquid to a second temperature below boiling. The second region ( 22; 222 ) has means ( 25; 225 ) for permitting the exit of steam therefrom separately from heated liquid. The flow heater cannot be operated so that bulk boiling of said liquid takes place in the second region ( 22; 222 ).

This application is a continuation of application Ser. No. 07/101,060, filed 9/24/87, now abandoned. FIELD OF THE INVENTION This invention relates to an isolation valve and in particular, to an isolation valve suitable for both vacuum and non-vacuum applications in a semiconductor processing environment. BACKGROUND OF THE INVENTION Vacuum gate valves are used in a variety of applications. In certain of these applications, high speed, high reliability, long life and low particulate generation are of the utmost importance. This is particularly true in processing systems for semiconductor wafers wherein vacuum gate valves are employed to provide isolation between loadlocks and process chambers and between different process chambers within the processing system. Recent trends in semiconductor processing include systems with a large number of vacuum processing modules interconnected by gate valves. See, for example, U.S. patent application Ser. No. 856,738 entitled "Modular Semiconductor Wafer Transport and Processing System", assigned to the assignee of the present invention. As these wafer processing systems become more complex and incorporate more vacuum gate valves, the reliability, long life and low particulate generation of the valve assumes greater importance since failure of a single valve may cause downtime for the entire system and excessive particulates generated by a particular valve may tend to contaminate the entire system. It is a general object of the present invention to provide a new and improved vacuum gate valve providing long life with low particulate generation. SUMMARY OF THE INVENTION An isolation valve is disclosed which includes a housing having a first port and a first seal member (seal plate) for sealing the first port. The first seal member is linked to a shaft which carries a guide means. To close the port, the shaft is first driven along its central axis in a first direction from a first position wherein the port is open and the guide means is not in contact with stops attached to the housing to a second position wherein the guide means contacts the stops. The shaft is then driven further along its central axis to a third position. As the shaft moves from its first position to the second position, a compression spring between the guide means and the shaft exerts a force between them which maintains the seal plate in a retracted position. As the shaft moves from the second position to the third position, the shaft moves relative to the guide means, and a mechanism linking the seal plate to the shaft causes the seal plate to be extended from its retracted position to an extended position for sealing the port. The guide means causes the motion of the sealing member to be perpendicular to a surface of the housing containing the port as the seal member seals the port. Rollers (cam followers) attached to the seal plate ride on the guide means, eliminating sliding friction between the guide means and the plate. To open the port, the shaft is driven along its central axis in the opposite direction which causes the seal plate to retrace its path of motion, first being retracted as the shaft is driven from the third position to the second position and then being translated as the shaft is driven from its second position to its first position. In one preferred embodiment, the valve includes a second seal member for sealing a second port in the housing. The second seal member is attached to the shaft by a linking mechanism. The motion of the second seal plate is the mirror image of the motion of the first plate with respect to the plane containing the central axis of the shaft and parallel to the flat parallel surfaces of the housing containing the first and second ports. An extension spring between the first and second seal members supplies a force which continually acts to retract the seal plates, eliminating play in the linking mechanism and extending the life of the O-rings embedded in the seal members. A locking mechanism is provided which prevents opening of the valve in response to a signal indicating an undesired condition of the driving mechanism, such as a loss of pressure in an air cylinder driving the shaft. This locking mechanism is located externally to a vacuum chamber containing the sealing member. This placement of the locking mechanism reduces the size of the portion of the valve in the vacuum chamber and eliminates particulate generation by the locking mechanism in a vacuum environment. A controller selects the magnitude of the force applied to the shaft by the driving mechanism. This permits valve life to be greatly extended by selecting a smaller force when the valve is sealing in an environment having approximately equal pressures on both sides of the valve and a larger force when the valve is sealing in an environment having unbalanced pressures on each side of the valve. For example, in one embodiment, the driving means is an air cylinder which is driven by an air supply at 45 psi when there is a vacuum in chambers on opposite sides of the valve and at 80 psi when there is a vacuum in a chamber on one side of the valve and atmospheric pressure in a chamber on the other side of the valve. These and other features of the invention may be more fully understood by reference to the drawings and accompanying Detailed Description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a cross-section of one embodiment of valve 100 of the present invention; FIGS. 2 and 3 show cross-sections of the valve of FIG. 1 along mutually orthogonal planes perpendicular to the plane of the cross-section of FIG. 1; FIG. 4 shows a cross-section of valve 100 with valve mechanism 101 in its open position in housing 1; FIGS. 5a, 5b and 5c show an exploded view of valve 100; FIG. 6 shows a schematic diagram of pneumatic mechanism 330 for driving valve 100 of FIG. 1. DETAILED DESCRIPTION FIG. 1 shows a cross-section of one embodiment of valve 100 of the present invention. FIGS. 2 and 3 are cross-sections of the valve of FIG. 1 along mutually orthogonal planes perpendicular to the plane of the cross-section of FIG. 1. FIGS. 1-3 show the valve mechanism 101 in its closed position within housing 1 with seal plates 3a and 3b pressed against interior surfaces 1a and 1b, respectively, of housing 1. FIG. 4 shows a cross-section of valve 100 with valve mechanism 101 in its open position in housing 1, thus providing communication between ports O 1 and O 2 in housing 1. Typically, ports O 1 and O 2 communicate with chambers C 1 and C 2 , respectively, one or more of which may be a vacuum chamber. FIGS. 5a 5b and 5c comprise an exploded view of valve 100. The same parts are designated by the same numbers in FIGS. 1-5c. The rigid valve parts may be made of stainless steel or any other suitable materials. Mounting plate 6 is secured to housing 1 by four screws 82. O-ring 43 seated in mounting plate 6 forms a vacuum seal between housing 1 and mounting plate 6. Two locating pins 83 (FIG. 5a) protruding from plate 6 assure proper alignment of plate 6 with housing 1. Valve shaft 9 extends through low friction bushing 85 which extends through mounting plate 6. Actuator block 4 of valve mechanism 101 is rigidly mounted on valve shaft 9 by a threaded connection (not shown) and secured with two set screws 85-1 and 85-2 and thus moves vertically with shaft 9 as indicated by arrows A and B in FIGS. 3 and 4, respectively. When actuator block 4 is mounted on shaft 9, end 9e (FIG. 1) protrudes above seat 4b of actuator block 4. Sealing is accomplished by forcing rectangular seal plates 3a and 3b to press against internal surfaces 1a and 1b, respectively, of valve housing 1, thus sealing off rectangular ports O 1 and O 2 in housing 1. O-rings 42a and 42b are seated in seal plates 3a and 3b, respectively, and completely surround ports O 1 and O 2 when valve mechanism 101 is in its closed position. If desired, housing 1 may be provided with opening 104 for communicating to a pumping mechanism (not shown) for evacuating valve chamber 103 internal to housing 1 to a selected pressure when valve mechanism 101 is in its closed position. Alternatively, if desired, one of the seal plates, e.g., seal plate 3a (FIG. 3) may be provided with two openings 91 for communicating chamber 103 to the chamber (e.g., C 1 ) associated with the seal plate so that valve chamber 103 may be evacuated to a selected pressure by pumping means (not shown) which pump chamber C 1 . Seal plate 3a is connected to actuator block 4 by means of generally rectangular links L a 1 through L a 4. Link L a 1 has two needle bearinqs 20-1 and 20-2. Link L a 1 is rotatably mounted to seal plate 3a by shaft 25 (FIG. 3) which extends through portion P 1 , through needle bearing 20-1 and through portion P 2 (FIG. 5a) of seal plate 3a. Link L a 1 is rotatably mounted to actuator block 4 by means of shaft 16-1 which extends across seat S 1 of actuator block 4 through needle bearing 20-2. Each link L a 2, L a 3 and L a 4 is identical to link L 1 and each is rotatably mounted to seal plate 3a by a corresponding shaft through one of its needle bearings and is rotatably mounted to actuator block 4 by a corresponding shaft 16-2, 16-3 and 16-4, respectively, through the other of its needle bearings. The use of needle bearings assures smooth operation with very low generation of particulates and without sliding friction in the bearings. Seal plate 3b is also connected to actuator block 4 by means of links L b 1 through L b 4. Again, each link L b 1 through L b 4 has two needle bearings and each link is rotatably attached to seal plate 3b by means of a corresponding shaft 25. Each link L b 1 through L b 4 is also rotatably mounted to actuator block 4 by one of shafts 16-1 through 16-4 which also attach links L a 1 through L a 4 to actuator block 4. In the exploded view of FIG. 5, links L a 1 through L a 4 have been labeled from left to right. Also links L b 1, L b 2, L b 3 and L b 4 are labeled from left to right. Links L b 1 through L b 4 are in horizontal register with links L a 1 through L a 4, respectively. When mounted on actuator block 4, link L b 1 is beneath link L a 1, link L b 2 is above link L a 2, link L b 3 is above link L a 3 and link L.sub. b 4 is beneath link L a 4. Shaft 16-1 mounts link L a 1 and link L b 2 to actuator block 4; shaft 16-2 mounts links L a 2 and L b 1 to actuator block 4; shaft 16-3 mounts links L a 3 and L b 4 to actuator block 4; and shaft 16-4 mounts links L a 4 and L b 3 to actuator block 4. Low friction washers 17 separate the links on each shaft from each other and from seal plate portions P1 and P2 of actuator block 4 to reduce generation of particles. The links are arranged so that they form four parallelograms and four toggle mechanisms at the same time. The parallelogram 108 including link L a 1 and L a 2 is shown in FIG. 4. Similarly, links L a 3 and L a 4 are contained in a parallelogram (not shown in FIG. 4). Links L b 1 and L b 2 are contained in a third parallelogram and links L b 3 and L b 4 are contained in a fourth parallelogram (not shown). These parallelograms assure that seal plates 3 remain mutually parallel during opening and closing of the valve. The pairs of links attached to shafts 16-1, 16-2, 16-3 and 16-4 form four separate toggle mechanisms which assure that both seal plates 3a and 3b move at the same rate of speed in opposite directions. These toggle mechanisms also provide mechanical advantage which amplifies the force applied to shaft 9. A pair of rollers 21 is mounted to each of seal plates 3a and 3b by a corresponding pair of shafts 24 which are fixedly mounted to seal plates 3a and 3b. Each of rollers 21 is provided with a needle bearing (not shown) to reduce particulate generation. Actuator block 4 is surrounded by frame (guide means) 106. Frame 106 includes a lower guide block 5 and an upper guide block 2 which are bolted together by screw 61. Shaft 9 extends through blocks 2 and 5 by means of bushings 22 and 23. Upper and lower guide blocks 2 and 5 are dimensioned so that rollers 21 are accommodated by recesses R 1 and R 2 formed by the joining of the upper and lower guide blocks. The vertical dimensions of recesses R 1 and R 2 are defined by internal surfaces 92U and 92L of upper and lower blocks 2 and 5, respectively. These internal surfaces are perpendicular to the center line of shaft 9. Recesses R 1 and R 2 serve as a guide for rollers 21. Recesses R 1 and R 2 restrict movement of rollers 21 and hence, seal plate 3a and 3b to linear motion with respect to frame 106 in opposite directions perpendicular to the center line of shaft 9. In one embodiment the vertical dimension of recess R 1 and R 2 is approximately 0.001 greater than the diameter of roller (cam follower) 21. Protruding end 9e of shaft 9 provides a guide means for low friction bushing 22 rigidly installed in upper guide block 2. Compression springs 31 extend between upper block 2 and actuator block 4 which exert force against upper block 2 and actuator block 4, spreading them apart and keeping them under preload. This preloading maintains seal plates 3a and 3b in their fully retracted position against surfaces 93U and 93L of frame 6 and links L a 1 through L a 4 and L b 1 through L b 4 at their maximum angle of inclination with respect to the horizontal as shown in FIG. 4 until upward movement of shaft 9 causes frame 6 to contact stops 94. Two extension springs 32-1 and 32-2 are connected between shafts 24 on seal plates 3a and 3b, respectively, and exert additional retracting forces on seal plates 3a and 3b at all times. Extension springs 32-1 and 32-2 eliminate play between shafts 25 and needle bearings 20-1 in all of the links and between shafts 16-1 through 16-4 and needle bearings 20-2 and prevent any rotational motion of plates 3a and 3b during their extension or retraction. While valve 100 is operational without the presence of the extension springs, and one embodiment was successfully tested for approximately 50,000 cycles before failure, the presence of springs 32-1 and 32-2 has greatly extended valve life. Three embodiments with these extension springs have each been tested for over 2.5 million cycles at 10 cycles per minute without failure. The valve can be cycled at a rate of up to at least 40 cycles per minute. Alignment of valve assembly 101 is controlled by actuator block 4 which is rigidly mounted on shaft 9. Anti-rotation clamp 8 with cam follower 49 is secured to shaft 9 by means of screw 66. Cam follower 49 is guided by vertical slot 109 in actuator housing 14, preventing rotation of shaft 9 about its central axis and providing proper alignment for actuator block 4, and thus, valve assembly 101. Shaft 44 of actuator 48 screws onto shaft 9. Actuator 48 is mounted to actuator housing 14 by screws 69. Housing 14 is secured to mounting plate 6 by screws 64. Bellows assembly 7 is used as a vacuum feedthrough. Pin 36 extends through shaft 9 through a circumferential slot (not shown) in flange 71 of bellows 7. Pin 36 retains bellows 7 to shaft 9, preventing axial movement of flange 71 with respect to shaft 9, while allowing a small amount of rotational movement to release torsional stress within bellows 7. This feature increases bellows life. O-rings 45 provide a vacuum seal. Valve 100 is shown in its open position in FIG. 4. In this position, seal plates 3a and 3b are retracted and rest against side surfaces 93U and 93L of upper block 2 and lower block 5, allowing communication between chambers C 1 and C 2 through ports O 1 and O 2 . In this lowered position an arm (not shown) located in one of chambers C 1 or C 2 may be extended through chamber 103 to the other chamber. To move valve 100 to its closed position shown in FIGS. 1-3, shaft 44 (FIG. 5c) of main actuator 48 is extended which causes shaft 9 and attached actuator block 4 and frame 106 supported thereon to move upward together until upper guide block 2 of frame 106 bottoms against stops 94 attached to housing 1. In one embodiment actuator 48 is an air cylinder and shaft 44 is the cylinder rod. Alternatively, shaft 44 may be driven by a linear motor or by hydraulic means or any other means, such as a lead screw, for providing linear motion. Up until the time when guide block 2 contacts stops 94 (which may be provided with polyimide buttons, not shown), seal plates 3a and 3b are held in their fully retracted position shown in FIG. 4 by the forces exerted by compression springs 31. As shaft 9 continues to move upward, frame 6 remains stationary against stops 94 and actuator block 4 further compresses springs 31. Simultaneously, the upward movement of shafts 16-1 and 16-4 with actuator block 4 causes general plane motion of the links attached thereto. The links simultaneously both rotate on their attaching shafts (16-1 through 16-4) and on shafts 25, which attach the links to seal plates 3a and 3b, and translate in planes parallel to the axis of shaft 9. This combination of motions extends the links to the extended position shown in FIG. 3. Rollers 21 rolling on upper guide surfaces 92U assure that seal plates 3a and 3b move linearly until seal plates 3a and 3 b are in the closed (extended) position shown in FIGS. 1-3. Because seal plates 3a and 3b move in a straight line perpendicular to the central axis of shaft 9 and also perpendicular to surfaces 1a and 1b of housing 1, seal plate O-rings 42a and 42b are compressed without any sliding motion. In particular, the motion of the seal plates is perpendicular to these O-rings at the moment of sealing. This assures clean operation and long-life for O-rings 42a and 42b. Extension springs 32-1 and 322 continuously apply retracting forces on seal plates 3, thus eliminating any possible backlash in the valve mechanism. To open the valve, the actuator 48 causes movement of shaft 9 in the direction shown by arrow B in FIG. 4. Downward movement of shaft 9 first causes retraction of sealing plates 3a and 3b as the links attached between the seal plates and shaft 16-1 through 16-4 again undergo general plane motion, including rotating on their attaching shafts and increasing their angle of inclination with respect to the horizontal. Upper guide block 2 is still held in position by springs 31 until seal plates 3a and 3b are in their fully retracted position. From this moment on, further downward movement of shaft 9 causes the entire valve assembly 101 to move in a downward direction. This sequence of motions assure that there is no sliding of O-rings at the time of breaking the seal between sealing plates 3a and 3b and interior surfaces 1a and 1b, respectively. It also ensures that no rotational forces are exerted on O-rings 42a and 42b. It is important to observe that in the above embodiment, the links connecting seal plates 3a and 3b to actuator block 4 are never fully extended, i.e., even when seal plates 3a and 3b are fully extended (FIG. 3), the links are inclined at a non-zero angle with respect to the horizontal, which angle increases as the seal plates 3a and 3b are moved to the open position (FIG. 4). This feature improves valve life by reducing stress on O-rings 42a and 42b and on the entire linking mechanism. This feature has also contributed to the extremely high reliability of the valve mechanism which has achieved over 2.5 million cycles without a failure. In other embodiments the valve mechanism may be dimensioned so that the links are fully extended (parallel to the horizontal) when the seal plates are extended or so that the attaching shafts 16-1 through 16-4 lie above their respective shafts 25 when the plates are fully extended, but this is not preferred. Valve 100 is equipped with locking mechanism 110 which prevents shaft 9 from moving downward (in direction B) in the event of loss of pressure to air cylinder 48. FIG. 1 shows locking mechanism 110 in its locked position with hard balls (e.g., of steel or ceramic) 51 jammed between taper 11 and the internal hard surface of housing 14 by the compressional force of spring 33 pressing ring 12 upward. Locking mechanism 110 includes base ring 13 which is rigidly fixed to shaft 9, compression spring 33, locking ring 12, a plurality of balls 51 which rest on top surface 12s of locking ring 12, taper 11, unlocking ring 10, retaining rings 50 and lock control air cylinder 120. Retaining ring 50a is bowed to spring load taper 11, eliminating clearance between taper 11 and retaining ring 50 above it. Antirotation pin 37 prevents rotation of body 95 of cylinder 120 with respect to shaft 9. Fittings 55 and 56 are air supply fittings for air cylinder 120. Compression spring 33 is seated in an annular groove in base ring 13 and supports locking ring 12 which is free to move with respect to shaft 9. Locking ring 12 is generally ring-shaped. Ring 12 has a groove in its lower surface for receiving compression ring 33 and its top surface 12s has a conical shape, i.e., is slopped downward toward the center of ring 12 (at an angle of approximately 5° in one embodiment). Taper 11 is a ring-shaped piece rigidly attached to shaft 9 which has a conically tapered outer surface 11s. Unlocking ring 10 is rigidly attached to body 95 of lock control air cylinder 120 by screws 67. Piston 96 of lock control air cylinder 120 is rigidly attached to shaft 9 so as to prevent vertical motion with respect to shaft 9. When pressure is not present under piston 96, locking mechanism 110 is in the position shown in FIG. 1 with, balls 51 being forced simultaneously against taper 11 and the internal surface of housing 14 by the compressive force of spring 33 pressing against ring 12. When air pressure is present beneath piston 96, cylinder body 95 and unlocking ring 10 attached thereto by screws 67 are forced downward with respect to shaft 9. The downward movement of unlocking ring 10 causes balls 51 to move downward and away from contact with the interior surface of housing 14 due to the angle of inclination of taper 11 with respect to the vertical (8° in one embodiment) and the slope of surface 12s. The locking mechanism is then in its unlocked position with balls 51 trapped between locking ring 12, unlocking ring 10 and taper 11. In this position, cylinder body 95, locking ring 10, balls 51, taper 11, locking ring 12, spring 33 and base ring 13 are free to move up and down with shaft 9. When pressure beneath piston 96 is withdrawn, spring 33 forces locking ring 12 and balls 51 upward locking shaft 9 as balls 51 are forced between the interior surface of housing 14 and taper 11. Jack screw 65 is provided for manual release of the locking mechanism. In one embodiment which further increases the life of the valve, the valve is capable of being operated at two different pressure levels: a low pressure level for normal operation when the same pressure is present in chambers C 1 and C 2 and a high pressure level for emergencies and to seal against atmospheric pressure in one of chambers C 1 and C 2 and a vacuum in the other. FIG. 6 shows a pneumatic schematic which describes one embodiment of pneumatic mechanism 330 which is capable of operating at two different pressure levels. Controller 300 controls the operation of pneumatic mechanism 330 which controls air supply to air cylinders 48 and 120. Pneumatic mechanism 330 includes flow control valves 206 and 208, direction control valve 210, pressure selection valve 212, pressure regulator 214, air on-off valve 216, air supply 218, pressure switch 222 and controller 300. Flow control valves 206 and 208 control the flow rate on air lines 201 and 203 and hence, the speed with which valve 100 opens and closes. Direction control valve 210 has an "open" position (shown in FIG. 6) in which air is supplied via line 201 above the piston of air cylinder 48 and a "close" position in which air is supplied via line 203 below the piston of air cylinder 48, thus opening and closing valve 100, respectively. Pressure selection valve 212 has a first position (shown in FIG. 6) which connects low pressure line 205 from pressure regulator 214 to direction control valve 210 and a second position which connects high pressure line 207 to direction control valve 210. FIG. 6 shows pneumatic mechanism 330 in its low pressure mode wherein high pressure air (e.g., 80 psi) from air supply 218 is blocked by pressure selection valve 212 and proceeds to pressure regulator 214 which supplies air at a reduced pressure (45 psi in one embodiment) via line 205. This air at a reduced pressure proceeds via pressure selection valve 212 and direction control valve 210 to air cylinder 48. Pressure switch 222 receives on line 224 air at the pressure of the air supply output of air supply 218 (nominally 80 psi in one embodiment). Pressure switch 222 is preset at a selected trip point (e.g., 70 psi). Whenever pressure switch 222 detects that the pressure supplied by air supply 218 is less than the trip point pressure, a signal is provided to controller 300 which causes on-off valve 216 to switch to the off position (not shown in FIG. 6) which blocks the high pressure air supply on line 209 and simultaneously vents air cylinder 120 via line 211 causing locking of locking mechanism 110. This provides a safety mechanism to prevent the valve from operating at unsuitable pressures. The sensors 200 and 201 (FIG. 4) in chambers C 1 and C 2 sense the pressure in chambers C 1 and C 2 , respectively, and provide signals representative of these pressures to controller 300 (FIG. 6). If either of these signals indicate a pressure exceeding a selected threshold value (e.g., 50 microns) which indicates a degradation of the vacuum in chamber C 1 or C 2 , controller 300 switches pressure selection valve 212 to the high pressure mode which connects high pressure line 207 to direction control valve 210. The ability to operate at different selected pressure levels increases the life of valve 100 by reducing stress on valve parts. While the above embodiment has two sealing plates, the valve of the invention is also operative with a single sealing plate, for example, sealing plate 3a. In this embodiment, sealing plate 3b in links L b 1 through L b 4 are not present and extension springs 32-1 and 32-2 are connected between plates 3a and actuator block 4. The above embodiments are meant to be exemplary and not limiting and many substitutions and modifications will be obvious to one of average skill in the art in the light of the above disclosure without departing from the scope of the invention.

An isolation valve includes a housing having a port and a seal plate for sealing the port. The seal plate is linked to a shaft which carries a guide frame. To close the port, a drive mechanism drives the shaft linearly in one direction. The seal plate first moves linearly with the shaft until the guide frame stops against the housing. The seal plate then moves linearly in a direction perpendicular to a surface of the housing containing the port until it seals the port. Motion of the drive shaft in the opposite direction causes the seal plate to retrace its path. In one embodiment, the valve includes a second seal plate for sealing a second port. A spring between the guide means and the shaft provides pre-load which maintains the seal plates in a retracted position until the frame stops against the housing. An extension spring between the first and second seal plates eliminates play in the link mechanism and extends valve life.

RELATED APPLICATION [0001] The present application is related to U.S. patent application Ser. No. ______, concurrently filed with this application and entitled “AN APPARATUS, METHOD AND SYSTEM FOR READING AN OPTICAL CODE WITH AUTHENTICATABLE INFORMATION.” The present application and the related application are commonly assigned. FIELD OF THE INVENTION [0002] The present invention relates generally to optical codes. More particularly, but not exclusively, the invention relates to preventing the fraudulent use of information stored in an optical code. BACKGROUND [0003] Any discussion of prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. [0004] Point of sale (POS) terminals are used throughout the retail industry to process purchase transactions. A POS terminal typically includes a personal computer (PC) core in a chassis, one or more displays, an optical code scanner with weigh scale, a cash drawer, a magnetic stripe reader (MSR), keyboard and a printer. The POS terminals can either be self-service or assisted service. [0005] The optical code scanner includes an imaging scanner and may also include a laser scanner. The two scanners use different technologies to independently read optical codes such as barcodes presented to the scanner. The laser scanner reads a barcode by sweeping a beam of laser light across a barcode, capturing data representing the reflected laser light, and then processing the captured data to recover information encoded in the barcode. An imaging scanner reads a barcode by capturing a complete image of the barcode and then processing the image to recover information encoded in the barcode. [0006] Optical codes, such as barcodes, are generally affixed to or printed on items being presented to a POS terminal for purchase. The optical codes include information about the item they are affixed to or printed on. This information can include identification information for the item and the weight of the item if it is prepackaged and sold by weight. Some retailers have experienced a type of fraud where a person presents a false optical code, sometimes on a cell phone, instead of scanning the actual item being presented to the POS terminal for purchase. The false optical code has weight information that either matches or is approximately equal to the actual item so a weigh scale of POS terminal does not detect the substitution. [0007] Therefore, to prevent the above fraud, as well as other related frauds, there is a need to determine if an optical code that is being presented to a POS terminal for scanning corresponds to the item being presented for purchase. SUMMARY OF THE INVENTION [0008] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. [0009] Among its several aspects, one embodiment of the present invention recognizes the need to prevent the use of a false optical code to identify an item. A false optical code is an optical code not authorized to be used to identify an item. A false optical code can be in printed form or displayed on an electronic device such as a cell phone. A false optical code may include inaccurate or false information and when used to identify an item causes the item to be misidentified or mispriced or both. One aspect of the present invention generates an optical code where a portion of the information included in the optical code is encrypted. The type of cryptography used authenticates the encrypted data and thus prevents unauthorized parties from generating encrypted data to create a false optical code or from using an optical code from another item. [0010] In still another embodiment, two optical codes are used. One or both of the optical codes includes encrypted data and the data from both optical codes are required before the encrypted data can be decrypted and authenticated. [0011] In accordance with an embodiment of the present invention, there is provided a scaling and labeling apparatus for generating and printing an optical code with encrypted data. The scaling and labeling apparatus including a computer memory adapted to store computer data and computer executable instructions; a weigh scale device adapted to determine the weight of items placed on the scale; a label printer device adapted to print labels with information about the items placed on the scale; and a processor in communication with the memory, weigh scale and label printer where the processor executes the instructions and where the instructions cause the processor to receive a weight for an item placed on the scale, calculate a total price of the item using the received weight, encrypt data related to the item where the data includes the item weight, generate a first optical code including the encrypted data and print using the label printer a first label that includes the first optical code. [0012] A more complete understanding of the present invention, as well as further features and advantages of the invention, will be apparent from the following Detailed Description and the accompanying Drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0013] The aspects of the claimed invention can be better understood with reference to the Drawings and the Detailed Description. The Drawings are not necessarily drawn to scale. Throughout the Drawings, like element numbers are used to describe the same parts throughout the various drawing, figures and charts. [0014] FIG. 1 is a high-level drawing in block form illustrating an exemplar embodiment of a scaling and labeling system. [0015] FIG. 2 is a high-level flow chart illustrating an exemplar method for generating a label for a variable weight item. DETAILED DESCRIPTION [0016] In the following description, numerous details are set forth to provide an understanding of the claimed invention. However, it will be understood by those skilled in the art that the claimed invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible. [0017] The term optical code, as used herein, includes both one and two dimensional barcodes. In addition, two dimensional barcodes include Quick Response (QR) codes and Data Matrix codes. The term optical code is not intended to be limited to just these examples but include machine readable codes that provide unique information or identification. [0018] Turning to FIG. 1 , there is provided a high-level drawing in block form illustrating an exemplar embodiment of a scaling and labeling system 100 . The system includes a computer server 180 connected to a scaling and labeling device 105 over a computer network 175 . The computer server 180 receives and sends data to the scaling and labeling device 105 . The scaling and labeling device 105 include a processor module 115 , a weigh scale 145 , a label printer 150 , communications controller 155 and a user display/touch screen 160 . [0019] Within the processor module 115 , there is included a processor 120 , a memory 125 and control circuitry 130 . The memory 125 includes both volatile and non-volatile memory. Software stored in the memory 125 is executed by the processor 120 and causes the processor 125 to control the devices and operation of the scaling and labeling device 105 . The control circuitry 130 provides an interface between the processor 120 and the memory 125 and between the processor 120 a data bus 140 used to communicate with other devices that comprise the scaling and labeling device 105 including but limited to the weigh scale 145 , the label printer 150 , the communications controller 155 and the user display and touch screen 160 . In some embodiments, all or a portion of the memory 125 is connected directly to the processor 120 . [0020] The scaling and labeling device 105 is used to determine the weight of a packaged item 165 where the item 165 is sold by weight. The weight of these items varies so the actual weight must be determined before the total price of each item can be calculated. Examples of such items include packaged meat, packaged cheeses and packaged deli products. The item 165 is placed on the weigh scale 145 and the weight of the item 165 is determined. The processor 120 receives the weight of the item 165 from the weigh scale 145 and then calculates a total price for the item 165 using the item's weight and a unit weight price for the item 165 . The processor 120 then generates a unique price label 170 for the item 165 and prints the label 170 using the label printer 150 . The unit weight price is entered on the touch screen 160 or retrieved from the computer server 180 . The processor 120 displays information including item weight and total price on the user display 160 . [0021] Included on the price label 170 is human readable information such as the unit price, total price, total weight and item identification information. The price label 170 further includes an optical code 171 that is generated by the processor 120 . The optical code 171 includes item identification information, price and weight information. In some embodiments, the optical code 171 also includes additional information such as an expiration date. [0022] A portion of the information stored in optical code 171 is encrypted by the processor 120 . The information is encrypted using a public-key cryptography system. A public-key cryptography system uses matched public and private keys to encrypt/decrypt data and authenticate the party that encrypted the data. In a public-key cryptography system, a party uses a private key of a key pair to encrypt data and publishes a matched public key of the key pair that is used to decrypt the encrypted data. The public key is the only key that will decrypt the data and the public key cannot be used to encrypt false data that is substituted for the encrypted data. The private key is kept secret but the public key is general available to anybody that has a legitimate need for it. Because only the public key can decrypt data encrypted by the matching private key, being able to successfully decrypt the data proves that the data was encrypted by the private key and generally used to authenticate the source of the data. [0023] In some embodiments, the process of encrypting the data includes performing a hashing function on some or all of the information stored in the optical code. A hashing function is cryptographic function that processes data to generate a unique signature, sometimes referred to as a hash. Generally, the hashing function is performed on information that will not be encrypted and/or information prior to being encrypted. Examples of hashing functions include MD5, SHA-3 and BLAKE. In the embodiment, the hashing function produces a first unique signature that is included as part of the encrypted data stored in the optical code. When the optical code is read, the encrypted data is also read and then decrypted using the matching public key. The hashing function is then performed on some or all of the decrypted data along with the data that was not encrypted to create a second unique signature. If the first and second unique signatures are identical, the encrypted data has been properly decrypted and the data has not been altered since the original hashing function was performed. [0024] The portion of the information stored in the optical code that is never encrypted or decrypted is referred to as clear text. The portion of the information stored in the optical code that is encrypted is referred to as plain text before it is encrypted and after it is decrypted and as encrypted data when it is encrypted. [0025] In some embodiments, a party identifier is stored in the optical code 171 . The party identifier is stored in clear text (never encrypted) and is associated with a party that generated the encrypted data. The party may be a company that packages, weighs and labels items or a company that contracts to have the work performed. In one example, the company is a store where items are packaged, weighed, labeled and placed on display for purchase. Items are then selected and presented to a POS terminal to be scanned for purchase. In another example, the company is a suppler to a store where the item is shipped to the store and placed on display for purchase. The item is then selected and presented to a POS terminal to be scanned for purchase. The party identifier is used by the POS terminal to retrieve or identify a public key that is then used to decrypt the encrypted data stored in the optical code 171 . [0026] In some embodiments, the process of encrypting the data does not involve using a public-key cryptography system but instead uses a simpler cipher that modifies/encrypts the original data using a first function where a second function can be used to recreate the original data. An XOR cipher is a one example of a function that encrypts and decrypts data but does not use a public key. An XOR cipher encrypts data by applying a bitwise XOR operation to every byte using a given key. The data is decrypted by reapplying the bitwise XOR operation to every byte using the same given key. In these embodiments, the size of the data prior to encryption is the same as after encryption. In addition, embodiments that use this type of cipher generally use one dimensional optical codes and the labeling of an item and the purchase of the item usually occur in the same store. The store can create the given key and make sure it is used to create the labeling for an item and also used by the POS terminals to decrypt the data. Because one dimensional optical codes (barcodes) are used, a laser scanner is able to read them. [0027] Turning to FIG. 2 , there is provided a high-level flow chart illustrating an exemplar method for generating a label for a variable weight item. This method is implemented using the scaling and labeling device 105 . In step 200 , the processor 120 receives information associated with an item 165 . The information can be entered on the user display/touch screen display 160 or it can be retrieved from the computer server 180 over the computer network 175 or a combination of both. The entered or retrieved information is associated with the item 165 and includes a description of the item, a price per unit weight and a private encryption key. The scaling and labeling device 105 uses a public/private cryptography system and the private encryption key to encrypt a portion of the information related to the item 165 . [0028] The cryptography system uses a public key and a matching private key. The private key is used to encrypt data and is kept secret while the public key is made public and is used to decrypt the data. Only matching keys will work to encrypt and decrypt data. In some embodiments the information associated with the item 165 includes party identification information associated with the encryption method. This party information identifies the company that operates the scaling and labeling device 105 and is used to retrieve a public key for the company that matches the private key used to encrypt the data. [0029] In step 205 , the item 165 is placed on the weigh scale 145 and the processor 120 receives a weight for the item 165 from the weigh scale 145 . In step 210 , the processor displays data for the item 165 on the user display/touch screen 160 . This information includes the weight of the item and the total price calculated by multiplying the weight of the item by the unit price for the item. [0030] In step 215 , the processor 120 encrypts data related to the item 165 . The data related to the item 165 includes the weight of the item 165 . In some embodiments, the data includes an expiration date that is used to determine when an item can not longer be sold. It also prevents the use of the optical code after the expiration date in a fraudulent manner. In still other embodiments, the data includes identification information about the item 165 . The processor 120 encrypts the data related to the item 165 using the private encryption key and a public/private key cryptography system. In some embodiments, the cryptography system is based on RSA's public/private key cryptography system. In other embodiments, the cryptography system is based on simple cipher such as an XOR cipher. [0031] In step 220 , the processor 120 generates a first optical code that includes the encrypted data and non-encrypted data. In step 225 , the processor 120 prints the first optical code 171 on a first label 170 using the label printer 150 . The first label 170 is then applied to the item. In some embodiments, a second optical code is generated and printed on a second label. The second label is then applied to the item 165 generally in an area away from the first label making it difficult for a cell phone to take a photo of both at one time. [0032] Although particular reference has been made to an embodiment that includes a scaling and labeling device and examples have been provided illustrating the invention in combination with a weigh scale and label printer, certain other embodiments, variations and modifications are also envisioned within the spirit and scope of the following claims. For example, there are embodiments where the invention is used in an automated assembly line and the weight of an item is communicated to the processor so no weigh scale is required. The processor uses the item's weight to generate the optical code and print a label including the optical code. In some embodiments, the invention includes a label application device that receives a printed label from the printer and automatically applies the printed label to the item. In still other embodiments, different cryptography systems are used encrypt and decrypt data.

An apparatus, method and system is provided for generating an optical code where a portion of the information stored in the optical code is encrypted prior to being stored in the optical code. In accordance with an aspect of the invention, a portion of the information stored in the optical code is encrypted to prevent the fraudulent creation of an optical code or use of the optical code on an item it was not created for or indented to be used with.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is the U.S. National Stage of International Application No. PCT/EP2010/060377 filed Jul. 19, 2010, and claims the benefit thereof. The [0002] International Application claims the benefits of Austrian Application No. A1379/2009 AT filed Sep. 2, 2009. All of the applications are incorporated by reference herein in their entirety. TECHNICAL FIELD [0003] The invention relates to a longitudinally reinforced railway vehicle. PRIOR ART [0004] Railway vehicles, in particular passenger vehicles, are nowadays mostly made as self-supporting metal constructions. In this case, a vehicle body shell is constructed from an under-frame, end walls and a roof. The under-frame must withstand the operational forces, especially the load, coupling pressure and tractive forces. To this end, the under-frame is often engineered as a framed construction and conventionally incorporates two outlying longitudinal beams, several cross-members joining these longitudinal beams and, and is reinforced at the ends of the vehicle. This reinforcement is effected by means of so-called end-pieces at the end of the vehicle, and main cross-members which also incorporate the mountings for the bogies (or individual axles, as applicable). For the purpose of approval of railway vehicles, it is necessary to satisfy certain norms, which are often different for each country. Among other requirements, these norms call for a demonstration that the railway vehicle can withstand a certain longitudinal force (coupling pressure) undamaged. The norm, which applies for Europe, UIC-566, calls for a coupling pressure of 2000 kN to be demonstrated, the norm which applies for the USA calls for 3550 kN. Even if the European norm is well capable of satisfaction by means of two longitudinal beams, a railway vehicle which is to be approved for the USA involves higher constructional costs. In this case, additional longitudinal beams are typically built in, these being known as center sills. As early as 1911, center sills were used in one of the first passenger carriages made of steel. (“Pullman Sleeping Car Glengyle”; The American Society of Mechanical Engineers; http://files.asme.org/ASMEORG/Communities/History/Landmarks/5629.pdf). [0005] To a specialist there are several known design solutions for the construction of center sills, for example US2002/0029721 proposes an under-frame construction made of two outlying and two inboard beams. U.S. Pat. No. 4,195,451 shows a single center sill, as does US 3,631,811. A particularly costly design is disclosed in U.S. Pat. No. 5,746,335. This design decouples the vehicle body shell from the center sill by means of hydraulic components. [0006] None of the known methods of construction makes it possible to build railway vehicles which can withstand very high coupling pressure but which can be manufactured with low design and material costs. Apart from this, the space requirement for conventional center sills is disadvantageous. SUMMARY OF THE INVENTION [0007] It is an object of the invention to specify a construction for a railway vehicle which can withstand a very high coupling pressure and at the same time is simple and cheap to manufacture. [0008] This object is achieved by a longitudinally reinforced railway vehicle as claimed in the independent claim. Advantageous embodiments are the subject of subordinate claims. [0009] In accordance with the basic idea behind the invention, at least one reinforcing tube is passed between the reinforced ends of the carriage, through openings in the cross-members, and is joined to the reinforced ends of the carriage. Here, the reinforcing tubes are not joined, in particular not welded, to the cross-members at the openings in the cross-members. At their ends, the reinforcing tubes are joined to the reinforced ends of the carriage by means of suitable force channeling fixtures. [0010] It is thereby possible to achieve the advantage of being able to manufacture a longitudinally reinforced railway vehicle with a significantly lower construction cost than is possible with the solutions conforming to the prior art. In particular, the construction cost of a welded center sill is eliminated, and also the space which is otherwise occupied by a center sill remains free for other built-in items. [0011] The inventive solution simplifies the building of a longitudinally reinforced railway vehicle because, in accordance with the invention, the reinforcing tubes are not welded to the cross-members. This eliminates a large number of complicated welded joints. [0012] It is of further advantage that, in accordance with the proposed solution, the entire compressive strength of the reinforcing tubes is used, because passing the reinforcing tubes through openings in the cross-members makes it impossible for them to buckle out of the latter. The normal distance between the cross-members in railway vehicles is generally adequate to prevent buckling of the reinforcing tubes. [0013] An important feature of the invention forming the subject matter is the complete elimination of all welded joints between the reinforcing tubes and the cross-members, which makes it possible to use even non-weldable materials for the reinforcing tubes. Thus it is also possible to use carbon fiber or Kevlar tubes, for example. In particular, it also simplifies the use of (non-weldable) high-tensile steel. [0014] The channeling of the compressive forces from the reinforced ends of the carriages into the reinforcing tubes is effected by means of suitable force channeling fixtures, which must be engineered according to the applicable pairing of materials and the spatial restrictions. If the pairing of the materials for the reinforced ends of the carriages and the reinforcing tubes is weldable, then the welding-together of these components is to be recommended. If welding is not possible or provided for, as applicable, then fixtures must be provided which are suitable for ensuring the reliable channeling of the forces into the reinforcing tubes and which compensate for the unavoidable length tolerances in the railway vehicle. For example, guide sleeves are to be recommended and, inlaid in these guide sleeves, wedges which compensate for the length tolerances. [0015] The reinforcing tubes can also consist of solid material (reinforcing bars). [0016] In accordance with the invention, provision is made to arrange the reinforcing tubes between the reinforced ends of the carriages. Here, one possibility is to arrange the reinforcing tubes between the two main cross-members, or alternatively between the two headstocks, wherein for the latter design the reinforcing tubes are passed through openings in the main cross-members. [0017] In a preferred embodiment of this invention, the reinforcing tubes are used in addition for transporting liquid or gaseous media. In this case, the end faces of the reinforcing tubes must be closed off and suitable connecting fixtures provided, and the dimensions of the reinforcing tubes must be specified allowing for the reduction in compressive strength resulting from these connecting fixtures. [0018] Equally advantageous is the use of the reinforcing tubes for the routing of electrical wires. In particular for the routing of high-voltage electrical wires, which would otherwise need to be fed in conductive tubes. Here it is also important that the reinforcing tubes are not welded to the cross-members, because this ensures that no irregularities due to welded joints can arise on the inner surface of the tube, which could damage the high voltage wires. [0019] A further preferred embodiment provides that the reinforcing tubes are passed through sleeves, which are introduced into the spaces between the openings in the cross-members and the reinforcing tubes. These sleeves will typically be made of plastic, and will improve the passage of the reinforcing tubes, so that even minor buckling is prevented, and eliminate practically any noise arising from the reinforcing tubes. In addition, these sleeves increase the load bearing capacity of the reinforcing tubes in an axial direction, because they prevent even minor buckling of the reinforcing tubes. BRIEF DESCRIPTION OF THE DRAWINGS [0020] The drawings show, by way of example: [0021] FIG. 1 a railway vehicle in accordance with the prior art. [0022] FIG. 2 an under-frame for a railway vehicle in accordance with the prior art. [0023] FIG. 3 a sectional view through an under-frame for a railway vehicle in accordance with the prior art. [0024] FIG. 4 a sectional view through an under-frame for a railway vehicle in accordance with the invention. [0025] FIG. 5 the passage of a reinforcing tube through a cross-member. [0026] FIG. 6 a sleeve. [0027] FIG. 7 an under-frame for a railway vehicle in accordance with the invention when a force is channeled in from the main cross-member. [0028] FIG. 8 an under-frame for a railway vehicle in accordance with the invention when a force is channeled in from the headstock. DETAILED DESCRIPTION OF THE INVENTION [0029] FIG. 1 shows, by way of example and schematically, a railway vehicle in accordance with the prior art. A railway vehicle incorporates a carriage body shell 1 and an under-frame 11 together with further components (axles, wheels etc.). The under-frame 11 is joined to the carriage body shell 1 and together with the carriage body shell 1 it bears its own weight and that of the load. Tensile and compressive forces are taken up and transferred solely by the under-frame 11 , for which purpose a reinforced carriage end 4 is provided at both ends of the under-frame 11 . This reinforced carriage end 4 takes up the forces introduced by the buffers or coupling drawhooks (or center coupling), as applicable. [0030] FIG. 2 shows, by way of example and schematically, an under-frame for a railway vehicle, in accordance with the prior art. The view shows an under-frame 11 from beneath. The under-frame 11 incorporates two longitudinal beams 2 , several cross-members 3 , a main cross-member 7 and a headstock 8 . The longitudinal beams 2 extend over the entire length of the railway vehicle, between the headstocks 8 , and together with the cross-members 3 form a frame which affords the railway vehicle the necessary rigidity. This frame is planked with a floor 9 which can, for example, consist of corrugated metal sheet and which forms the basis for the passenger floor structure. At each of the two ends of the under-frame 11 , a reinforced carriage end 4 is provided. This reinforced carriage end 4 incorporates a headstock 8 and a main cross-member 7 . These components are exceptionally solidly constructed, because all the loadings and operational forces are channeled through them. The main cross-members 7 are fitted with a mounting fixture for a bogie or an axle, as applicable, the headstocks 8 have mounting fixtures for buffers and couplings. In the exemplary embodiment shown in FIG. 2 , the main cross-member 7 and the headstock 8 of a reinforced carriage end are joined to a short centrally positioned longitudinal beam. Compressive forces in the longitudinal direction of the railway vehicle can be transmitted almost exclusively by the two longitudinal beams 2 , because the carriage body shell 1 (not shown in FIG. 2 ) is not suitable for transmitting compressive forces, due to its construction. [0031] FIG. 3 shows by way of example and schematically a sectional view through an under-frame of a railway vehicle in accordance with the prior art. This shows a section through an under-frame 11 across the longitudinal direction of the railway vehicle. The two longitudinal beams 2 are joined by a cross-member 3 which, for the purpose of saving weight, have holes in it. In the exemplary embodiment shown, the two longitudinal beams 2 are essentially U-shaped in construction. A floor 9 of corrugated metal sheet forms the lower external body shell of the railway vehicle. [0032] FIG. 4 shows by way of example and schematically a sectional view through an under-frame of a railway vehicle in accordance with the invention. This shows a section through an under-frame 11 across the longitudinal direction of the railway vehicle, as in FIG. 3 . In accordance with the invention, the cross-members 3 incorporate openings 6 through which reinforcing tubes 5 are passed. At the places where they pass through the cross-members 3 , these reinforcing tubes 5 are not joined, in particular they are not welded, to the cross-members 3 , or the openings 6 in the cross-members 3 , as applicable. The reinforcing tubes 5 pass unattached through the openings 6 in the cross-members 3 . In the exemplary embodiment illustrated, two reinforcing tubes 5 are shown, but any other number of reinforcing tubes 5 is possible. The openings 6 are designed such that they prevent the buckling of the reinforcing tubes 5 . For this purpose, it is necessary that the openings 6 have a diameter which is only minimally greater than that of the reinforcing tubes 5 . [0033] FIG. 5 shows by way of example and schematically the passage of a reinforcing tube through a cross-member. It shows a longitudinal section through a reinforcing tube 5 in the region of its penetration through a cross beam 3 . A sleeve 10 surrounds the reinforcing tube 5 and guides it within an opening 6 in the cross-member 3 . During the assembly of the under-frame 11 , this sleeve 10 is pushed onto the reinforcing tube 5 , after which it is pushed into the opening 6 . By this means, the reinforcing tube 5 is passed through the opening 6 with no play, by which means any noise generation is suppressed and the improved guidance of the reinforcing tube further reduces its buckling when it is subject to loading. [0034] FIG. 6 shows by way of example and schematically a sleeve. This shows a three-dimensional view of a section through a sleeve 10 . This single-part sleeve 10 can equally well be made in two parts so that it can also be mounted after assembly of the under-frame 11 has been carried out. [0035] FIG. 7 shows by way of example and schematically an under-frame of a railway vehicle in accordance with the invention, in which force is channeled in from the main cross-member. This shows a plan view of an under-frame 11 at one end of a railway vehicle. The other end of the railway vehicle is constructed as a mirror image. The under-frame 11 incorporates two longitudinal beams 1 , several cross-members 3 , two main cross-members 7 and two headstocks 8 . The longitudinal beams 11 extend over the entire length of the railway vehicle between the headstocks 8 and together with the cross-members 3 form a frame. The cross-members 3 are shown as horizontally sectioned. Running between the main cross-members 7 at the two ends of the under-frame, in the longitudinal direction along the railway vehicle, are two reinforcing tubes 5 . These reinforcing tubes 5 penetrate the cross-members 3 , through openings 6 in these cross-members 3 . The reinforcing tubes 5 are not joined to the cross-members 3 at the sites where they penetrate the latter. For the purpose of making this feature of the invention forming the subject matter clear, the openings 6 are shown over-enlarged. Into these openings, sleeves 10 , like that shown in FIG. 5 , can be inserted (not shown) in order to improve the guidance of the reinforcing tubes 5 and to prevent any noise generation. At each end of the reinforcing tube 5 is provided a force channeling fixture 12 , which locates the end of each reinforcing tube 5 and channels the compressive forces from the main cross-member 7 into the reinforcing tubes 5 . The engineering of this force channeling fixture 12 will be determined, among other matters, by the pairing of the materials for the reinforcing tube 5 and the main cross-member 7 . If these materials can be welded to each other, then it is recommended that they should be welded at this location, which enables the force channeling fixture 12 to be particularly simply designed. [0036] FIG. 8 shows by way of example and schematically an under-frame of a railway vehicle in accordance with the invention, in which the force is channeled in from the headstock. The under-frame 11 from FIG. 7 is shown, with the force being channeled into the reinforcing tubes 5 directly from the headstock 8 . The reinforcing tubes 5 run between the headstocks 8 at the two ends of the under-frame 11 and penetrate through not only the cross-members 3 but also the main cross-members 7 . For the purpose of making this clear, the main cross-member 7 is shown as a partial section. It is to be recommended that where the reinforcing tubes 5 pass through the main cross-member 7 they are fitted with sleeves 10 (not shown). The present exemplary embodiment shows the principle of channeling forces from the headstock 8 , in specific embodiments attention must be given to the maximum bearing span of the reinforcing tubes 5 , in order to prevent any buckling of the reinforcing tubes 5 . If necessary, additional support locations (cross-members) should be provided here.

A longitudinally reinforced railway vehicle includes a body, longitudinal girders, cross-girders, and reinforced carriage ends. Reinforcement tubes which are guided within recesses of the cross-girders are arranged in the longitudinal direction between the reinforced carriage ends.

TECHNICAL FIELD [0001] The present invention relates to an arrangement for non-destructive inspection of joint layers in a multilayer structure which comprises at least a first and a second layer joined by a joint layer. The invention also relates to a method of performing inspection of a joint layer in a multilayer structure. STATE OF THE ART [0002] When two layers, of the same or of different materials, are joined by a joining layer, or a bonding layer, voids and cavities are often produced. Such cavities or voids may cause a lot of problems for example when heat should be conducted from hot components, when Radio Frequency (RF) conductors are grounded, and they may also have a detrimental effect on mechanical strength and tensile properties. For microelectronic components within the field of microelectronic or particularly within microwave applications, the problems concerning heat conductivity and radio frequency consist in that heat and radio frequency signals have to travel longer distances in the joint material, if there are cavities, before a heat sink or ground respectively is reached. Another serious problem is that, after lamination by a joining material, there is no way to establish if there actually are any cavities and, if there are, then where they are located, without destroying the laminated structure. One method that frequently is used is based on destructive tests in which the joining layer is revealed. Through such testing it is possible to determine how different parameters of the joining process affect the quality of the joint, but such methods can of course not be used for fast, non-destructive inspection. By using ultrasonic microscopes it is possible to detect voids or cavities. Such equipment is however expensive, slow, and will in practice often destroy the electronic since it has to be merged into a liquid medium. Furthermore it can not be used for on-line operation. [0003] Another known device comprises a micro-focus X-ray apparatus. This device is however also large and it is extremely difficult to obtain a contrasting effect between the air filled cavity and the bonding material, for example the polymer part of an adhesive film. A method based on such a device is not appropriate for use in an automatic system for detection of cavities or voids. The equipment is expensive and has to be kept under strict control, only used by skilled operators, and well protected. [0004] Other known methods are based on using IR-(Infra Red) cameras for measurements on seals or joints. The joints are heated up and subsequently passively cooled down. The temperature is measured by use of IR cameras and the response of a pulsed procedure is compared to “good” reference seals or joints. It is possible to detect angular errors of components, bad placement in X-Y-direction and if there is too little or too much joint material. Such methods are however not relevant for bonding materials based on polymers such as for example thermosetting materials, e.g. adhesive films, thermoplastic materials etc. Furthermore such methods are only applicable to directly exposed seals or joints in the line-of-sight of an optical detection equipment. Such methods can be not be used for inspection of joints or bonding materials used to laminate two materials, or two layers wherein the joint layers are not accessible for direct, visual inspection. [0005] DE-C1-19 841 968 shows to a method to be used for large objects. A laser is used for heating up, point by point. Small cavities can not be detected, and it would not function within electronics or microelectronics. It is also a slow method, and cavities will be detected one by one. The method is based on scanning, which is appropriate for large objects, e.g. airplane wings, but it does not work for small sized components. SUMMARY OF THE INVENTION [0006] What is needed is therefore an arrangement for inspecting invisible or concealed joints for joining materials (or layers) which is non-destructive. Further such an arrangement is needed which is small and not bulky. An arrangement is also needed which is suitable for automatical operation for detecting cavities or voids in concealed joints joining two materials. Further an arrangement is needed which can be used for on-line operation or for sampling tests or for inspection of singular multilayer structures in which two layers are joined by a joint layer. [0007] Further still an arrangement is needed which can be used for detection of voids or cavities in adhesive materials based on polymers such as thermoplastic materials and thermosetting materials. In addition thereto an arrangement is needed which is cost-effective and fast. Still further an arrangement is needed which can be used within the area of microelectronics or particularly within microwave electronics and to detect small cavities, particularly of millimeter size. The cavities are generally gas-filled (e.g. air) but they may also be vacuum cavities. [0008] Therefore the present invention provides for an arrangement for non-destructive inspection of joint layers in a multilayer structure comprising a first layer, a second layer and a joint layer for joining said first and second layers. The arrangement comprises a heating arrangement for homogeneously heating up a second layer of the multilayer structure, or a second outer surface, also called the second outer surface of the multilayer structure, a detecting arrangement which comprises a thermographic imaging system for registering the infrared radiation pattern representative of the temperature distribution on the other (first) outer surface of the multilayer structure. Then all cavities can be seen at the same time. Processing means are also provided for, based on the temperature distribution pattern, establishing at least the presence of cavities in the concealed joint layer. In an advantageous implementation the thermographic imaging system comprises an IR-radiation detection arrangement. The infrared radiation emitted from the first outer surface is then detected. The IR-detection arrangement may with advantage be connected to a computer system including an image processing software and/or to a display screen. [0009] If there is a cavity in the joint layer, it takes longer time for the heat transferred to the second outer surface by the heating means, to be transported from the second outer surface towards the first layer if there is a cavity inbetween since then the heat can be said to be conducted so as to make a deviation around the cavity and therefore it will take more time until the region above the cavity is heated up to the same temperature as surrounding areas or regions under which there are no cavities. Thus, the radiation emitted is measured or observed by an infrared camera during a thermal transition i.e. thermal transport during heating up and then it is possible to observe or detect at least the location of a cavity. During a thermal transition, heating up in this case, the surface temperature distribution depends on whether there are any cavities or not in the joint layer. Therefore, with a substantially evenly heated second outer surface, shown as different surface temperatures on the opposite, first, outer surface, infrared radiations of various powers, will correspond to the presence of cavities. Spots with a lower temperature indicate that there is a cavity in the underlying joint layer. [0010] In a particular embodiment the heating arrangement comprises a heating plate or similar enabling a fast and even, homogeneous heating up of the second outer surface of a multilayer structure. It may be brought in close contact with the second outer surface, but in an alternative implementation heating up is achieved in a contactless manner such that the whole inspection procedure may be contactless. Many different kinds of heating means may of course be used, e.g. lamps, lasers etc. Heating up may be done in principle from any temperature as long as the properties of particularly the joint layer are not affected in an adverse manner. The multilayer structure may e.g. also be cooled down to a low temperature before heating up. [0011] As referred to above the detecting arrangement is used to detect the infrared radiation pattern representative of the temperature distribution on the first outer surface. Particularly the detection is performed or initiated substantially simultaneously with the heating up of the second outer surface to register the transient process of heat transport across the multilayer structure, or in other words the thermal transition. In a particular implementation the detecting means are at least activated before the temperature distribution has been stabilized across the first outer surface. [0012] The processing system may comprise a processing system for, based on the registered temperature distribution information, establishing cavities of at least a minimum predetermined size. In a particularly advantageous implementation the processing means comprises a processing system able to determine the size and/or the dimensions of cavities of at least a given minimum size. Alternatively all cavities possible to detect are indicated, i.e. there is a natural limit given by what the equipment actually is able to detect. [0013] In an advantageous implementation the arrangement is used for automatic on-line operation such that a number of subsequent multilayer structures can be inspected, which structures are arranged, e.g. on a line, to move in relation to the arrangement. [0014] In an alternative implementation the inspection arrangement is mobile and then it may be implemented for automatic on-line operation as well, with the difference that multilayer structures are fixed but the inspection arrangement is moved. [0015] Alternatively or additionally the arrangement is manually operable. The arrangement may also be operated automatically in general, although not for on-line operation. [0016] Particularly the arrangement is used to inspect multilayer structures in which the coefficients of thermal conductivity of the first layer and of the joint layer are lower than that of the second layer. Particularly the coefficient of thermal conductivity of the first layer is lower than 50 [W/mK]. In one particular implementation the coefficient of thermal conductivity of the first layer is about 3 [W/m.K]. The important thing is that the first layer shows a thermal conductivity and a thermal diffusivity which are not too high. The joint layer particularly comprises a polymer based material, such as a thermoplastic material or a thermosetting a material, an adhesive film or similar with a comparatively low coefficient of thermal conductivity. The second layer particularly comprises a metal, a metal alloy or a composite, or graphite, whereas the first layer may comprise a ceramic material, e.g. alumina, LTCC or a polymer, such as FR 4 plates or a metal, metal alloy or metal a composite. (The second layer may show good heat conducting properties). [0017] The heating arrangement particularly heats up the second layer from e.g. room temperature to a temperature of approximately 200° C. or below that, preferably to a temperature between 100-150° C. Also other temperatures are of course also possible, it should however be prevented that the joint layer melts or that heating in any way is detrimental to the joint layer material properties. [0018] To meet one or more of the objects initially referred to, the invention also discloses a method for non-destructively inspecting joint layers in a multilayer structure comprising at least a first layer with a first outer surface forming one of the outer surfaces of the multilayer structure, and a second layer with a second outer surface forming the opposite outer surface of the multilayer structure and a joint layer for joining said first and second layers. [0019] The method includes the steps of; providing the structure between a heating arrangement and a detecting arrangement; heating up the second layer/the second outer surface; establishing the temperature distribution on the first outer surface by means of a thermographic imaging system; analyzing the IR radiation pattern or the temperature distribution pattern for detecting cavities or voids in the joint layer. [0020] In a particular implementation the step of establishing the temperature distribution comprises the steps of; recording the infrared radiation pattern emitted from said first surface by means of an equipment based on IR-radiation detection, e.g. an IR video, IR scanner or an IR-camera; converting the emitted infrared radiation pattern to a temperature distribution pattern. The method may also comprise the step of; manually providing a multilayer structure in a position enabling inspection between the heating arrangement and thermographic imaging system. Alternatively the method includes the steps of; automatically feeding a plurality of subsequent multilayer structures on a line into position for inspection; operating an IR-detection arrangement forming a thermographic imaging system on-line. In an advantageous implementation the method includes the steps of; applying heat to the second layer in a manner allowing a fast and even heating up; activating the detecting arrangement substantially simultaneously with heating up to allow recording of the transient procedure of heat migration on the first outer surface. The detecting arrangement may also be activated substantially as soon as a multilayer structure is disposed on, or close to a heating arrangement or when the heating arrangement is activated in case it is not already in a heating phase. [0021] The method may particularly comprise the step of heating up the second layer from e.g. room temperature to a temperature of approximately 200° C. or below that, preferably to a temperature between 100-150° C. (The starting temperature does of course not have to be room temperature; it may well be a lower or a higher temperature; in principle any temperature will do while still considering that the materials are not negatively affected neither by the starting temperature, nor by the temperature to which heating up is performed.) [0022] In an advantageous implementation the method includes the step of; evaluating the temperature distribution pattern using a processing system to determine the size of cavities, e.g. cavities exceeding a given value. The method may comprise the steps of; providing reference values on temperature differences or temperature distribution patterns corresponding to cavities of a given size; comparing obtained temperature distribution patterns or temperature values with said reference values to determine the sizes of cavities. [0023] Particularly the method may include the steps of; defining a maximum limit for the size of acceptable cavities; comparing the sizes of a detected cavity with said maximum value; automatically activating an alarm if a joint layer contains a cavity/cavities exceeding said maximum value. In a particular implementation the activation of the alarm leads to the step of; for on-line operation; automatically indicating a multilayer structure having a joint layer with one or more cavities exceeding the maximum value. Particularly the method is implemented for multilayer structures in which the second layer comprises a metal, metal alloy or composite, graphite or similar, whereas the first layer comprises a ceramic material, or a polymer or a metal, metal alloy, or a (metal) composite. The joint layer may comprise a polymer, e.g. a thermoplastic material or a thermosetting material. The second layer should have a coefficient of thermal conductivity which is comparatively high whereas the first layer should have a coefficient of thermal conductivity which is comparatively low such that heat is not too quickly transported throughout the first layer, in other words that the temperature is not evened out too quickly on the first outer surface. (Although there will still be a faint pattern left after a long time). The faster the heat is distributed to/on the first outer surface, the faster IR-detection equipment is required. [0024] It is an advantage of the invention that it gets possible to, in a fast, reliable and efficient manner detect cavities in concealed joint layers, particularly for the above mentioned or similar materials, and that it can be implemented for on-line operation or automatically such that multilayer structures can be inspected without being destroyed and in some cases even contactlessly. BRIEF DESCRIPTION OF THE DRAWINGS [0025] The invention will in the following be further described in a non-limiting manner and with reference to the accompanying drawings in which: [0026] [0026]FIG. 1 shows an arrangement according to the invention, [0027] [0027]FIG. 2 shows an arrangement according to the invention for online operation, [0028] [0028]FIG. 3 schematically illustrates the transportation of heat from a second, heated up, layer to the outer surface of a first layer when there is a cavity in the joint layer, [0029] [0029]FIG. 4 schematically illustrates the temperature distribution on the outer surface of a first layer, and [0030] [0030]FIG. 5 is a flow diagram describing the procedure of detecting cavities in a joint layer of a multilayer structure. DETAILED DESCRIPTION OF THE INVENTION [0031] In advantageous implementations of the inventive concept, an arrangement and a method, as will be further described below, can be used to detect voids and cavities in joint layers, particularly within microelectronics. Even more particularly an arrangement according to the invention is used to determine the size of said voids or cavities. Generally a multilayer structure, or a plate, consists of two plates of a solid material 1 , 2 which are laminated through the use of the thin joint layer 3 , cf. FIG. 1. Undesired cavities produced during lamination are detected in that the multilayer structure quickly is heated up, in a particular implementation from below, for example by a heating plate or more generally a heating arrangement. A first outer surface, in the implementation of FIG. 1 the top surface, will then show a temperature distribution which indirectly is measured at the same time as the second outer surface, here the bottom outer surface of the second layer, is heated up, by the use of IR-detection equipment 20 that detects the emitted IR radiation. During the transient procedure when heat is transported or spread on the first outer surface or the upper surface, the cavities can be observed on the upper outer surface (in this case). The pattern through which the cavities, if present, can be detected, will also remain after temperature “equilibrium” has been reached, although, then the pattern is fainter. [0032] A precondition is that the coefficient of heat conductivity of the first layer 1 , i.e. in this case the top layer, from which the IR radiation is detected, is not too high because then the heat would be transported too quickly to be detected; at least for comparatively simple, conventional IR-cameras would it spread too quickly. Also for the joint layer the coefficient of heat conductivity should not be too high for the same reasons. The heat conductivity of the second layer 2 , which is heated up by the heating arrangement 10 , is however actually not critical, and it may be high. [0033] Examples of materials for which the inventive concept can be implemented are thick film ceramic with a coefficient of heat conductivity, λ below 50 W/mK, LTCC (Low Temperature Cofired Ceramic), and a thermoplastic material with λ=2-3 W/mK. The inventive arrangement/method can of course also be implemented for any other materials and the indication of these materials should of course not be interpreted as limitative. [0034] The IR-detection equipment 20 is generally connected to processing means 30 . Generally an optical software system can be used in which differences in color, greyness or reflection from an object are registered and compared to a reference model. However, this can be done in many ways. The main point is that in one way or another temperature differences are correlated with actual cavities, particularly sizes of cavities. In an advantageous implementation an alarm is activated if some limiting value, e.g. different colors or different greyness in the detected IR pattern, a given temperature gradient, a given temperature difference etc., is exceeded. An indication may be provided that the inspected multilayer structure contains unacceptable cavities. This can be provided for in different manners. [0035] [0035]FIG. 2 shows an arrangement similar to that of FIG. 1 which here is used for on-line operation. A plurality of subsequent multilayer structures 41 , 42 , 43 , 44 , 45 are inspected through the use of the detecting arrangement. When a multilayer structure, according to the figure multilayer structure 42 , is in position enabling inspection, the second layer, here the bottom layer is heated up by heating arrangement 10 which is mounted on a carrier element. Substantially simultaneously IR-detection equipment, e.g. an IR-camera 20 is activated to make a number of pictures with a given frequency. The results of the IR-radition measurements are processed by a processing means 30 , and if it is detected that multilayer structure 42 contains one (or more) cavities exceeding a given size, or simply detectable cavities, it is indicated that mulitlayer structure 42 should be discarded or repaired or whatever the relevant action may be. It is also possible to avoid setting of a limit relating to the size of a cavity, by simply using the natural limit as resulting from a practical point of view, i.e. when a cavity is detectable, a multilayer structure is not acceptable, or needs to be indicated as containing cavities. [0036] The invention will now be further described with reference to one embodiment in which inspection is performed of a multilayer structure 40 comprising a first layer or a substrate of a ceramic material and a second layer 2 comprising a thin carrier which are laminated by the use of an adhesive joint layer or bonding layer 3 which for example may comprise an adhesive film. When the joint layer 3 is heated up during the bonding operation, there is a risk that cavities are produced and such cavities will remain in the joint after lamination and cooling down of the multilayer structure, e.g. a multichip module (MCM). [0037] As referred to earlier the consequences may be that grounding under RF-conductors will be of inferior quality, or that the heat conduction is poor at critical spots etc. [0038] In an advantageous implementation the joint layer is inspected when the joint layer has been provided on the second layer 2 , e.g. the thin carrier, and the first layer 1 , e.g. the substrate, has been provided on top thereof through application of heat and pressure. The carrier or the second layer may be in direct contact with a thin adhesive film. Above the adhesive film a first layer comprising a ceramic plate which is thicker than the adhesive layer is provided. The carrier layer may for example have a coefficient of heat conductivity (λ) of 180 [W/mK] at 300 K and the first layer may be a ceramic with a coefficient of heat conductivity of less than 50 at 300 K. The adhesive film may have a coefficient of heat conductivity of about 5 [W/mK] at 300 K. It should be clear that these parameters are merely given for exemplifying reasons and indicate one multicarrier structure among many different kinds of structures which with advantage can be inspected by the use of the inventive arrangement. [0039] According to the invention cavities are detected by the use of thermodynamical principles. As a starting point a heat wave is created by fast heating up under the second layer 2 which, according to one embodiment is provided on a heating plate at a temperature of 150° C. The first outer surface, e.g. the top layer or said first layer 1 , also denoted the substrate, will be heated up within seconds, homogeneously with the exception of the part(s) that is/are located above a cavity in the joint layer 3 . The temperature on this spot will be delayed and it will generally not even quite reach the temperature of the surroundings. The first outer surface, i.e. the top of the substrate, is examined by an IR-camera and a number of pictures are taken during a given time interval and a pattern results above a cavity. The temperature difference ΔT will depend on the coefficient of heat conductivity in the first layer at the relevant temperature, the thickness of the second layer, the dimensions of the cavity in the horizontal directions, i.e. parallell to the outer surfaces, and the thermal diffusivity of the first layer. ΔT is the temperature at a point in the first layer above the joint layer where it is homogeneous i.e. where there are no cavities, minus the temperature at a point in the first layer above the cavity, i.e. T s -T cav ). [0040] In FIG. 3 the principle of the heat flow to the first outer surface is very schematically illustrated. It should be noted that the thickness of the cavity is irrelevant in practice as well as in theory. If the wetting is bad, and a slot is produced which is about some micrometers thick, heat conduction is prevented. The illustrated cavity is distinct and it has a distinct outer border and it is singular. In reality it is generally less distinct and a plurality of other cavities may exist in the neighborhood. The figure will still explain that the procedure quite well. In the figure the arrows indicate the transport of heat and T CAV indicates the temperature on the substrate above the cavity, whereas T s illustrates the surrounding temperature on the substrate, i.e. the temperature on the first outer surface when there are not cavities in the joint layer. Thus the arrows illustrate the transport of heat when the carrier (second layer) 2 has been brought in close contact with e.g. a heating plate (or heated up in any other appropriate manner). In one advantageous implementation the heating arrangement comprises a plate with holes in it and a vacuum pump such that the multilayer structure is forced against the plate due to the produced vacuum to prevent an uneven distribution on the upper surface due to something else than cavities. [0041] [0041]FIG. 4 schematically illustrates an example of a temperature distribution obtained with the method according to the present invention to illustrate the differences in temperature when at there are cavities in the joint layer. It is here supposed that a multilayer structure, e.g. of the dimensions and materials as discussed above is provided with two cut-outs in the joint layer. One cut-out comprises a circle with radius 5.5 mm and the other cut-out comprises a square with side 1.7 mm. The structure is temporarily attached (e.g. by the suction action of a vacuum pump) to heating plate and it is heated to a temperature of 150° C. [0042] T 1 corresponds to the temperature on the upper surface of the first layer above the circular cut-out and T 2 corresponds to the detected temperature above the square shaped cut-out. [0043] T 3 and T 4 correspond to temperatures measured on the upper surface in regions with no cavities. It can be seen that a larger cavity (the circle) produces a larger area with a lower temperature than a smaller cavity (corresponding to the square shaped cut-out). Moreover, the difference ΔT c =T 3 -T 1 is approximately 3,4° C. whereas ΔT sq =T 4 -T 2 approximately is 2,6° C. This is merely shown to illustrate an example on what can be detected and that a larger cavity gives a larger area with reduced temperature and it is based on experimental results showing that also small cavities can be detected. [0044] In principle any appropriate IR-detection equipment can be used. It is used to detect the radiation of heat from a surface. All normal surfaces of a composite material will show a maximum intensity in the middle of the IR-domain. This IR-radiation is possible to detect by the equipment, e.g. a camera, and by use of appropriate software, a temperature map can be formed with a given resolution. Generally temperature difference of 0.2° C. can be detected. Long-wavelength IR-cameras measure IR-radiation between 8-12 μm which the best resolution around 40 μm. A short-wavelength camera detects wavelengths of 2-5.4 μm. Both kinds of cameras can be used. In order to avoid IR-radiation in a camera, from the lens and all other surfaces, the camera is advantageously kept at a low temperature and infrared radiation contributions from the camera itself are, to the largest extent possible, subtracted before an image is presented representative of the temperature distribution of the object, i.e. the first outer surface. Mostly this is done automatically in the camera. As referred to earlier, it does not have to be IR-cameras, but scanners, videos etc. [0045] It should be clear that above merely some examples on materials were given. Generally the second layer comprises a metal, metal alloy or a metal composite, i.e. a thermal expansion controlled materials may be used. It may also comprise diamond, graphite etc. The first layer may comprise a ceramic material such as alumina, Al 2 O 3 , LTCC (Low Temperature Cofired Ceramic) or a polymer, such as FR 4 plates or a metal alloy such as Kovar. The joint layer particularly comprises a polymer-based material such as a thermoplastic material, a thermosetting material, an adhesive film or similar. Generally the first layer and the joint layer should have a coefficient of heat conductivity which is not too high whereas the second layer well might have a higher coefficient of heat conductivity. Generally D, wherein D is the thickness of the first layer, and/or the thermal diffusivity α=λ/c p ×ρ, wherein λ is the coefficient of heat conductivity, ρ is the density and c p is the heat capacitivy, should be as low as possible which means that for a greater thickness D, a lower α is required and vice versa. Otherwise the resulting temperature distribution pattern will be less pronounced which imposes higher requirements on the IR-detection equipment, i.e. for a thicker material or for a higher thermal diffusivity, unless this is balanced by a lower value on α and D respectively, a faster IR-detection equipment will be needed. Particularly cavities having a size e.g. down to 1-2 mm can be detected. [0046] [0046]FIG. 5 is a schematical flow diagram describing a procedure of first heating up the bottom layer of a multilayer structure, 100 . In an alternative embodiment heating up is provided on the top layer in which case the top layer is the second layer. Then of course the IR-detection equipment is mounted to detect the IR-radiation pattern on the bottom layer instead. The IR-detection arrangement is activated substantially simultaneously or at the same time as heating up is initiated to e.g. make a number of pictures during a given time interval, 101 . The IR-radiation pattern emitted from the outer surface of the top (bottom) layer on the other side of a joint layer is registered, 102 , and the IR-radiation pattern is converted into a temperature distribution pattern, 103 , in any appropriate manner. The temperature differences are then interpreted to establish cavities in the joint layer, 104 . Alternatively the IR-radiation pattern is interpreted since it is by experience known which IR-radiation pattern would correspond to a given temperature distribution pattern which information then is provided by the software of a processing means. Then is somehow indicated if an inspected multilayer structure contains cavities, it may be cavities of a given size or larger than that or it may simply be cavities which are detectable since there is a natural limit determining which size of cavities that can be detected (for a given equipment and for given properties of the multilayer structure), 105 . [0047] It should be clear that the concept also applies to multilayer structures containing more than one joint layer used to laminate a second layer and a first layer and a first layer and another first layer, e.g. when then is provided more than one ceramic layer or first layer which also are joined by joint layers. It should also be clear that the invention is not limited to the specifically illustrated embodiments, but that it can be varied in a number of ways without departing from the scope of the appended claims.

The present invention relates to an arrangement for non-destructive inspection of joint layer(s) in a multilayer structure ( 40 ) comprising at least a first layer ( 1 ) with a first outer surface, a second layer ( 2 ) with a second outer surface and a joint layer ( 3 ) for joining said first and second layers. It comprises a heating arrangement ( 10 ) for homogeneously heating up said second outer surface of the multilayer structure ( 40 ), a detecting arrangement ( 20 ) comprising a thermographic imaging system for registering the infrared radiation pattern representative of the temperature distribution on said first outer surface of the multilayer structure ( 40 ) and processing means ( 30 ) for, based on the temperature distribution, establishing at least the eventual presence of (a) cavity/cavities in the joint layer ( 3 ).

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention pertains to a method for the production of an anode for X-ray tubes, consisting of a base element and a coating that emits X-ray radiation, the coating differing from the base element. 2. Description of Related Art To produce X-ray radiation, materials that emit X-rays when impacted by a focused electron beam are used. The high-melting-point metals tungsten and molybdenum and their alloys, for example, are materials typically employed, depending on the desired type of X-ray radiation. In medical diagnostics, rotary anodes are often used for X-ray tubes in the form of axial-symmetrical disks for the generation of X-ray radiation. In most cases, only one portion of the surface is designed in the form of a ring-shaped path--the so-called focal track--in the region directly impacted by the electron beam. This focal track uses a comparatively thin coating of material to generate the X-rays. The base element of the rotary anode consists of other high-melting-point materials. The specific material properties of the coating, such as lattice, thermal conductance, thermal expansion, mechanical properties, and thickness are important factors for the practical behavior of the focal track coating during X-ray operation. A permanent residual porosity has an adverse effect on the thermal conductance, the fatigue crack resistance, and the gas evolution in the X-ray tube. This means that the greatest possible density values are desirable for the comparatively thin focal track coating. A reduced fatigue crack strength is primarily expressed by a greatly increasing roughening of the focal track with increased use, and by a reduced X-ray yield associated with the fatigue cracking. The focal track coating has been produced to this time primarily by means of powder-metallurgical methods (e.g., pressing, sintering, and forging). In the case of metallic materials used for the base element, the coating is primarily produced in one working step of the base element by coating the base element with the powder mixtures. In this manner, density values for the coating of 96-98% of the theoretical density are attained as the standard. A production method of this type for the focal track coating is low in cost, but results in properties that are not the optimum, particularly with regard to fatigue crack behavior. In particular, where graphite is used as the base element material, the linkage of the base element with an independent focal track coating, produced by powder metallurgy is difficult. In contrast to powder metallurgy, a focal track coating may also be applied by known deposition coating methods, preferably by chemical vapor deposition (CVD) or even by physical vapor deposition. Of course, with vapor deposition, densities of nearly 100% of the theoretical density can be attained for the focal track coating. However, due to significantly greater manufacturing costs, vapor deposition production methods have been generally limited to production of rotary anodes with graphite bodies. Vapor deposition has not been able to replace the method of powder metallurgy for manufacturing the focal track coating. As a somewhat lower-cost coating method with a number of processing advantages, the method of conventional plasma spraying can be used. This applies in particular when the method is applied under a controlled atmosphere, i.e., under a vacuum or inert gas atmosphere. In conventional plasma spraying, the material for the focal track coating is radially introduced as a powder into a plasma beam generated by a dc arc discharge, then melted in the plasma beam and the molten droplets are deposited on the base element. Some important advantages of this method are the high application power per unit time, a coating temperature that is adjustable over a broad range, and the avoidance of chemical compounds that are difficult to neutralize. However, in the conventional plasma spray method, in spite of intensive development efforts around the world in recent years, focal track coatings with a maximum density of only 93% of the theoretical density have been attained. These densities provide unsatisfactory results for rotary anodes coated in this way with regard to fatigue cracking and gas evolution properties. The known thermal post-treatment methods that can be used, in theory, to obtain an increase in the density have only limited lid effectiveness in practice, or they have only limited applicability due to the effects on the material of the base element and/or on the composite behavior. This applies in particular to the use of graphite as a material for the base element. Under these restricting conditions, the thermal post-treatment to achieve post-compression will not be sufficient and complete gas evolution of the focal track coating will not occur. Due to these disadvantages, manufacture of rotary anodes, in which the focal track coating was applied with conventional plasma spraying is not common. Existing methods of powder metallurgy, vapor deposition and conventional plasma spraying have failed to achieve satisfactory coatings at low cost. SUMMARY OF THE INVENTION It is therefor an object of the invention to provide a low-cost method for manufacture of the coating emitting the X-ray radiation for the production of anodes for X-ray tubes. It is a further object that the coating fully satisfies, or even exceeds, the standard used today with regard to its practical behavior, particularly its fatigue crack strength. This objective is achieved by applying the coating, which emits X-ray radiation, by inductive vacuum plasma spraying. It is also an object of the invention that the fatigue crack strength of coatings applied by inductive vacuum plasma spraying is superior to coatings produced by powder metallurgy. It is also an object of the invention for the coating emitting the X-ray radiation to be applied by repeated overcoating of individual spray layers with a total thickness between 0.4-0.6 mm. As a rule, 20-50 overcoating steps with individual layers of the spray layer are recommended. It is also an object of the invention that before application of the coating emitting the X-ray radiation, a recess with roughly the depth of the desired coating thickness is worked into the base element in the region of this coating. In this manner, a level surface coating can be achieved by simple grinding to a plane of the adjoining anode base element. It is also an object of the invention for the deposition to take place under an inductively linked power between 50-100 kW and at a delivery rate of the spray powder between 10-50 grams/min. Under these conditions, a total and thorough melting and sufficient overheating of the melt droplets will be obtained. It is also an object of the invention, in comparison to parameters usually applicable to conventional plasma spraying, that the plasma particle beam passes over the surface to be coated at a comparatively low relative speed. This speed is preferably selected so that maximum temperatures of 1,400-2,400° C. will prevail in the vicinity of the point of impact of the core zone of the plasma particle beam. The base element to be coated is itself preferably heated to a temperature of 1,000-1,500° C. for this step. It is also an object of the invention that the plasma beam and the base element are moved with respect to each other in such a manner that the central point of impact of the plasma particle beam on the anode surface, and the center line of the active focal track concentric to the axis of anode rotation, at least roughly coincide. Thus, the particle stream from the plasma beam is adjusted so that the particle stream of the plasma beam arriving within the active focal track only encompasses that region located within the half-value width of the Gaussian particle distribution of the plasma particle beam. The result is that the edge of the plasma particle beam (which is less favorable for the layer structure) is shifted mostly to regions of the anode surface located outside of the active region of the focal track. The term "active region of the focal track," means the region impacted directly by the electron beam for the generation of X-ray radiation. It is also an object of the invention that the anode be subsequently subjected to an annealing treatment. The purpose of this annealing is both for an additional improvement of the lattice properties by means of diffusion processes, and also for gas evolution from the anode. The type of annealing treatment is dependent on the material, among other factors, used for manufacture of the base element of the rotary anode. In the case of a base element consisting of a high-melting-point metal, the annealing treatment is carried out at temperatures between 1,200-1,600° C. for a period of 1-20 hours, whereas in the case of rotary anodes in which graphite is used for the base element, as a rule it is carried out at temperatures up to 1,300° C. for a period of up to about 10 hours. In the case of a graphite base element, the possible formation of adverse carbides in the boundary region can be delayed by known diffusion barrier layers, e.g., rhenium. It is also an object of the invention that the base element of the anode is made of graphite, molybdenum, or a molybdenum alloy and the coating emitting the X-ray radiation can consist of a tungsten-rhenium alloy. The invented method will be explained in greater detail based on the manufacturing examples and based on the figures. BRIEF DESCRIPTION OF THE DRAWINGS ______________________________________FIG. 1 A basic sketch of one variant of the method according to this invention. FIG. 2 A graphic illustration of the average values of focal track roughening (Ra, on the vertical axis) of focal track coatings as a function of time (h, on the horizontal axis) on rotary anodes produced according to this invention and by the use of powder metallurgy. One plot illustrates the present invention (B), while the other plot illustrates results of powder metallurgical methods (A). FIG. 3 Illustrates a ground micrograph of the focal track of a rotary anode with focal track coatings produced according to this invention, with a cross section shown at a 200X magnification. FIG. 4 Illustrates a ground micrograph of the focal track of a rotary anode with focal track coatings produced by powder metallurgy, with a cross section shown at a 200X magnification. FIG. 5 Illustrates a ground micrograph of the focal track of a rotary anode with focal track coatings produced by conventional plasma spraying, with a cross section shown at a 200X magnification.______________________________________ DETAILED DESCRIPTION In recent years, a new variant of plasma spraying, the so-called inductive vacuum plasma spraying, has been developed. The difference of this specific plasma spraying method with respect to conventional plasma spraying methods rests in the fact that the plasma is created by inductive heating, so that the spray powder can be axially applied in a simple manner just before formation of the plasma beam. Therefore, and due to the lesser expansion rate of the plasma due to the inductive heating, the powder particles remain much longer in the plasma beam. This improves the energy transmission from the plasma to the individual particles of the spray powder, so that even larger powder particles are heated entirely above their melting temperature and can be deposited as fully molten droplets. The inductive vacuum plasma spray method is thus suitable for the use with a low-cost spray powder, to accommodate a wider range of particle size, in comparison to conventional plasma spray methods. The superior results achieved with inductive vacuum plasma spraying are somewhat surprising, because the density value of the coatings applied by inductive vacuum plasma spraying can equal the density values of coatings produced by powder metallurgy, but as a rule are below the values for powder metallurgy. Though the density values of the coating applied by inductive vacuum plasma spraying are less than the theoretical density, the reasons for improvement in fatigue crack strength cannot be unambiguously explained. One possible explanation for superior fatigue crack strength, with reduced coating density, might be the crystalline lattice produced. It appears that with inductive vacuum plasma spraying, special crystalline lattices are produced that clearly differ from the lamellar solidification lattices that are usually obtained by conventional plasma spray methods. Two examples for producing a focal track coating according to this invention are provided. MANUFACTURING EXAMPLE 1 Disk-shaped base elements for rotary anodes made of TZM, a molybdenum alloy with 0.5% titanium, 0.08% zirconium, up to 0.04% carbon, and the remainder molybdenum, with a diameter of 120 mm and a blunt conical outer region with a 20° opening angle, are mounted to a shaft provided with a rotation drive and installed in a vacuum chamber. Coating of the individual base elements is accomplished by means of a plasma gun with a 50-mm inside diameter with inductive heating, and a power output of 65 kW with spray powder from a tungsten alloy with 5% rhenium in a powder fraction between 15-63 μm. The spray powder is axially introduced at a delivery rate of 30 grams/min by means of Ar carrier gas. Before beginning the powder injection, the base element is heated to 1500° C. The rotation rate of the base element is 10 rpm. The inductive vacuum plasma spray gun is moved to the side of the middle line of the focal track coating running concentric to the rotary anode axis, specifically in such a manner that the axis of the plasma gun continuously moves at a rate of 2 mm/sec alternately on both sides of this middle line up to a maximum distance of 5 mm on each side. In a coating process lasting about 4 min, by means of about 50 sequentially deposited single layers, a focal track coating of about 1 mm total thickness and 25 mm width is thus applied. After completion of the coating process, the rotary anodes are cooled to below 100° C., removed from the vacuum chamber and subsequently the focal track coating is ground to a thickness of 0.7 mm. The rotary anodes, now processed to this level, are then subjected to a high-vacuum annealing at a temperature of 1600° C. for a period of 90 min. For comparison purposes, disk-shaped base elements like those used for the previously described method were produced by powder metallurgy with an 0.8-mm-thick focal track coating made of a tungsten-5-rhenium alloy. In this case, a layering of the TZM-powder mixture for the base element on the one hand, and for the tungsten-rhenium alloy for the focal track coating on the other hand, was produced and pressed; the pressed blank was sintered and, by forging and mechanical processing, the final shape was produced. Next, the rotary anodes were subjected to the same high-vacuum annealing as those obtained according to this invention. The density of the focal track coatings was determined by the buoyancy method. The focal track coatings applied according to this invention have a density of 97.2% of the theoretical density, whereas the focal track coatings produced by powder metallurgy have a density of 97.4% of the theoretical density. MANUFACTURING EXAMPLE 2 Referring now to FIG. 1, in an additional manufacturing example in a similar rotary anode base element as in Manufacturing Example 1, a ring-shaped groove of 0.8 mm depth is incorporated into the region of the focal track. Next, the rotary anode base element is coated with essentially the equivalent coating conditions according to the invented method used in Manufacturing Example 1. The sole difference in this coating variant is that the inductive vacuum plasma spray gun is not moved to the side during the coating, but rather is held stationary, specifically such that the center axis 5 of the plasma gun 3 coincides with the center line 4 of the focal track coating 2 concentric to the rotary anode axis, and such that the plasma beam and thus the particle beam is adjusted so that the half value width of the particle distribution HW coincides with the width of the active region B of the focal track coating 2 as is illustrated in FIG. 1. For a better overview, FIG. 1 shows the particular local distribution of particles in the region of the focal track not directly on the rotary anode base element 1 but above it, and not true to scale but in a greatly exaggerated display. After application of the focal track coating 2 and annealing, the surface of the rotary anode is mechanically abraded, except for an amount S of 0.7 mm. This produces the final thickness and a clean lateral delimitation of the focal track coating to the rotary anode base element. The rotary anode produced with this coating variant has a somewhat better density of 97.8% of the theoretical density, compared to the rotary anodes produced according to Manufacturing Example 1 of this invention. Thus, Manufacturing Example 2 corresponds to a reduction in residual porosity of roughly 20%. Rotary anodes produced according to the invention, as described in manufacturing examples 1 & 2, were installed in a test stand for X-ray rotary anodes and tested cyclically under standard conditions using the following parameters: ______________________________________ Tube voltage 90 kV Tube current 400 mA Shot time 2 sec Pause time 58 sec______________________________________ The test was interrupted at specified times in order to determine the focal track roughening as a measure of the fatigue crack resistance and the associated reduction in the X-ray dosage yield. FIG. 2 illustrates the particular average values of the rough depth Ra obtained from three rotary anodes per variant. The significantly better roughening values for rotary anodes produced according to this invention (B), is easy to see. After a 100-hour test time, the average rough depth Ra for anodes produced according to this invention, with Ra measured in the perimeter direction, was 24% less than the corresponding roughening value of comparison rotary anodes produced by powder metallurgy (A). After conclusion of the 100 hour comparison test, a ground microsection was prepared from the rotary anode coated according to this invention, from the rotary anode produced by powder metallurgy and from the rotary anode produced by conventional plasma spraying. Photographs of these microsections using a 200X magnification are presented in FIGS. 3, 4 and 5 respectively. The lattice of the inductive, plasma-sprayed focal track according to FIG. 3 presents a fundamentally different morphology than the focal track in FIG. 4 produced by powder metallurgy. The impacting molten droplets when using inductive vacuum plasma spraying exhibit transcrystalline features upon solidification, that is, they are also used as crystallization surfaces for the next arriving molten droplets. Thus, once a layer starts to grow, the direction of this growth will be essentially retained, at least for numerous molten droplets, and the lamellar lattice structures usually observed in conventional plasma spraying, with their poorly bonded grain boundaries, will not form. These poor grain boundaries are clearly visible in FIG. 5 using the example of a focal track coating of a rotary anode produced by conventional plasma spraying. In the case of inductive vacuum plasma spraying, the original boundaries between sequentially solidified droplets can only be found in some cases, due to intracrystalline clusters of micropores, but they are surrounded by additional transcrystalline grains. In conclusion, the resulting, predominately column lattice with a dense structure presented in FIG. 3 is obtained. The grain boundaries between these column crystallites running in the direction of crystal growth are well defined and free of collections of micropores. In contrast to this, the grains in the powder-metallurgy lattice according to FIG. 4 are mostly isotropic. The residual porosity appears here in the form of coarse pores. The fatigue cracks of the focal track coating in a rotary anode produced according to this invention appear in the form of microcracks running essentially perpendicular to the surface. These microcracks have a less harmful effect at the moment of roughening of the surface than the cracks in rotary anodes produced by powder metallurgy. The stronger roughening and the destabilization of the surface lattice in rotary anodes produced by powder metallurgy are clearly discernible due to failures at the grain boundaries in FIG. 4. In another comparison test, rotary anodes made according to the invention had roughening after 100 hours of use that compared to the roughening of comparison anodes after only 20 hours of use. Thus, the expected lifetime of rotary anodes made according to the invention may be five times greater than rotary anodes made according to previous methods. The manufacturing examples describe particularly favorable variants of a manufacturing process according to this invention, but the invention is by no means limited to them. For example, it is also possible to apply the focal track coating not by means of several, sequentially layered spray coatings, but rather all at once in a single layer. Although an illustrative embodiment of the present invention, and various modifications thereof, have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments and the described modifications, and that various changes and further modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.

The invention pertains to a method for the production of an anode for X-ray tubes, and the invention also pertains to the resulting anode. In the invention, a coating that emits X-ray radiation is applied by inductive vacuum plasma spraying onto the base element. Using this method, an improved fatigue crack resistance and a reduced roughening of the coating on the anode is achieved.

CLAIM OF PRIORITY This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application earlier filed in the Korean Intellectual Property Office on 19 Nov. 2003 and there duly assigned Serial No. 2003-82391. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent display and, more particularly, to an electroluminescent display in which an electromagnetic shield is adapted to shield a first power supply voltage line to prevent the occurrence of noise or the like on the power supply voltage due to internal or external electromagnetic waves. 2. Description of the Related Art In recent years, various flat panel displays have been developed which are capable of reducing weight and volume which are disadvantages of a Cathode Ray Tube (CRT). Such flat panel displays include liquid crystal displays, field emission displays, plasma display panels, electroluminescent displays, and the like. Among these displays, the electroluminescent display uses carriers, such as electrons and holes, to excite a fluorescent material to display images or video so that it may be driven by a low direct voltage and has a faster response speed. For these reasons, the electroluminescent display has been in the spotlight as the next generation display and research on new electroluminescent display products have accelerated in recent years. An electroluminescent display can be classified into a passive matrix type and an active matrix type. The active matrix electroluminescent display has an active switching device arranged in each pixel. A voltage or current is supplied to drive each emitting device in response to the image data of the pixel. An electroluminescent display includes a first upper power supply voltage line, a first lower power supply voltage line, a second power supply voltage line, a scan driver, a data driver, a first active power supply voltage line, and a pixel region. The electroluminescent display includes the scan driver supplying a selection signal, the data driver supplying a data signal, the pixel region emitting light in response to the selection signal and the data signal respectively supplied from the scan driver and the data driver, the first upper and lower power supply voltage lines delivering first power supply voltages, the second power supply line delivering a second power supply voltage, and the first active power supply voltage line supplying the power supply voltages from the first power supply voltage lines and the second power supply voltage from the second power supply voltage line to the pixel region. When the selection signal and the data signal are respectively supplied from the scan driver and the data driver to the pixel region, switching transistors drive transistors of the pixel region, and the first and second power supply voltages are supplied to the pixel region via the first power supply voltage lines and the second power supply voltage line so that each pixel of the pixel region emits light. Each of the first power supply voltages is opposite to that of the second power supply voltage. However, the electroluminescent display described above has a problem that the waveform of the power supply voltage is distorted due to internally or externally supplied electromagnetic waves. That is, the power supply voltages delivered via the first upper and lower power supply voltage lines have noise which results from externally or internally supplied electromagnetic waves, thereby resulting in non-uniform brightness. SUMMARY OF THE INVENTION The present invention, therefore, solves aforementioned problems associated with the electroluminescent display described above by providing an electroluminescent display having an electromagnetic shield arranged in parallel with the first power supply voltage lines. A specific voltage is supplied to the electromagnetic shield to attract the electromagnetic waves so as to shield the first power supply voltage lines from electromagnetic waves that would otherwise affect the power supply voltage. In an exemplary embodiment of the present invention, an electroluminescent display includes: a pixel region including devices arranged therein and adapted to emit light in response to a data signal; a scan driver adapted to supply a switching signal to a gate electrode of a first switching device; a data driver adapted to supply data information to a source electrode of the first switching device; a conductive power supply line adapted to supply a first power supply voltage to the pixel region, and an electromagnetic shield adapted to shield electromagnetic waves having electric or magnetic field characteristics. The electroluminescent display further preferably comprises a shielding voltage generator adapted to supply a voltage to the electromagnetic shield. The electromagnetic shield is preferably adapted to generate a second power supply voltage. The second power supply voltage preferably has a polarity opposite to that of the first power supply voltage. The electromagnetic shield preferably comprises a conductive interconnection line arranged in parallel with the first power supply voltage line. In another exemplary embodiment of the present invention, an electroluminescent display includes: a pixel region including devices arranged therein and adapted to emit light in response to a data signal; a scan driver adapted to supply a switching signal to a gate electrode of a first switching device; a data driver adapted to supply data information to a source electrode of the first switching device; a conductive power supply line adapted to supply a first power supply voltage to the pixel region, and at least one metal line arranged in parallel with the first power supply voltage line. The at least one metal line is preferably arranged inside the first power supply voltage line. The at least one metal line is alternatively preferably arranged outside the first power supply voltage line. The at least one metal line alternatively preferably comprises metal lines respectively arranged inside and outside the first power supply voltage line. The electroluminescent display further preferably comprises a shielding voltage generator adapted to supply a voltage to the at least one metal line. The shielding voltage generator is preferably adapted to supply a second power supply voltage having a polarity opposite to that of the first power supply voltage to the at least one metal line. In yet another exemplary embodiment of the present invention, an electroluminescent display includes: a pixel region including devices arranged therein and adapted to emit light in response to a data signal; a scan driver adapted to supply a switching signal to a gate electrode of a first switching device; a data driver adapted to supply data information to a source electrode of the first switching device; a conductive power supply line adapted to supply a first power supply voltage to the pixel region, and a metal line arranged parallel with the first power supply voltage line and adapted to be connected to a ground terminal. BRIEF DESCRIPTION OF THE DRAWINGS A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: FIG. 1 is a plan view of an electroluminescent display; FIG. 2 is a plan view of an electroluminescent display in accordance with a first embodiment of the present invention; FIG. 3 is a plan view of an electroluminescent display in accordance with a second embodiment of the present invention; FIG. 4 is a plan view of an electroluminescent display in accordance with a third embodiment of the present invention; and FIG. 5 is a plan view of an electroluminescent display in accordance with a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a plan view of an active matrix type electroluminescent display. An electroluminescent display 100 includes a first upper power supply voltage line 110 , a first lower power supply voltage line 120 , a second power supply voltage line 130 , a scan driver 140 , a data driver 150 , a first active power supply voltage line 160 , and a pixel region 170 . As shown in the FIG. 1 , the electroluminescent display 100 includes the scan driver 140 supplying a selection signal, the data driver 150 supplying a data signal, the pixel region 170 emitting light in response to the selection signal and the data signal respectively supplied from the scan driver 140 and the data driver 150 , the first upper and lower power supply voltage lines 110 and 120 delivering first power supply voltages, the second power supply line 130 delivering a second power supply voltage, and the first active power supply voltage line 160 supplying the power supply voltages from the first power supply voltage lines 110 and 120 and the second power supply voltage from the second power supply voltage line 130 to the pixel region 170 . When the selection signal and the data signal are respectively supplied from the scan driver 140 and the data driver 150 to the pixel region 170 , switching transistors drive transistors (not shown) of the pixel region 170 , and the first and second power supply voltages are supplied to the pixel region 170 via the first power supply voltage lines 110 and 120 and the second power supply voltage line 130 so that each pixel of the pixel region 170 emits light. Each of the first power supply voltages is opposite to that of the second power supply voltage. The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the present invention are shown. FIG. 2 is a plan view of an electroluminescent display in accordance with a first embodiment of the present invention. An electroluminescent display 200 includes a first upper power supply line 210 , a first lower power supply voltage line 220 , a second power supply voltage line 230 , a scan driver 240 , a data driver 250 , a first active power supply voltage line 260 , a pixel region 270 , a metal line 280 , and a shielding voltage generator 290 . As shown in FIG. 2 , the electroluminescent display 200 according to an embodiment of the present invention includes the scan driver 240 , the data driver 250 , the pixel region 270 emitting light in response to a selection signal and a data signal respectively supplied by the scan driver 240 and the data driver 250 , the first upper and lower power supply voltage lines 210 and 220 delivering first power supply voltages, the first active power supply voltage line 260 supplying the power supply voltages from the first power supply voltage lines 210 and 220 to the pixel region 270 , the second power supply voltage line 230 supplying a second power supply voltage to the pixel region 270 , the metal line 280 arranged in parallel to the first power supply voltage lines 210 and 220 to shield electromagnetic waves, and the shielding voltage generator 290 supplying a shielding voltage to the metal line 280 . When the selection signal and the data signal are respectively supplied by the scan driver 240 and the data driver 250 to the pixel region 270 , switching and drive transistors (not shown) of the pixel region 270 are turned on. As the drive transistor of the pixel region 270 is turned on, the power supply voltages supplied to the first upper and lower power supply voltage lines 210 and 220 are supplied to the pixel region 270 via the first active power supply voltage line 260 so that the pixel region 270 emits light. In addition, the shielding voltage generator 290 supplies a specific voltage to the metal line 280 so that a specific current flows through the metal line 280 arranged in parallel to each of the first upper and lower power supply voltage lines 210 and 220 . The specific voltage supplied to the metal line 280 preferably has a polarity opposite to that of each first power supply voltage. In addition, the metal line 280 and the first power supply voltage line 210 are spaced apart from each other by a constant interval to be parallel to each other as shown in FIGS. 2 and 3 , However, the metal line 280 and the first power supply voltage line 210 can be isolated from each other by a separate insulator interposed therebetween. As a result, when electromagnetic waves from an external source and having magnetic or electric field characteristics are supplied to the first power supply voltage lines 210 and 220 , the electromagnetic waves are shielded by the metal line 280 arranged in parallel to the first power supply voltage lines 210 and 220 . That is, the voltage supplied to the metal line 280 has a polarity opposite to that of the first power supply voltage so that the electromagnetic waves are attracted by the metal line 280 due to electrical characteristics which flow from positive to negative or from negative to positive. As a result, the power supply voltage is not affected by the electromagnetic waves. FIG. 3 is a plan view of an electroluminescent display in accordance with a second embodiment of the present invention. As shown in FIG. 3 , another embodiment of the present invention has ground terminals 291 , each of which being connected to the metal line 280 . Accordingly, the electromagnetic waves supplied to the first power supply voltage lines 210 and 220 are attracted by the metal line 280 to be grounded so that the power supply voltages are shielded from the electromagnetic waves. FIG. 4 is a plan view of an electroluminescent display in accordance with a third embodiment of the present invention. As described above, the metal line 280 is arranged in the first upper power supply voltage line 210 as in the first embodiment. However, in the third embodiment, the metal line 280 can also be arranged outside the first upper power supply voltage line 210 . That is, the metal line 280 is arranged outside the first upper power supply voltage line 210 so as to be spaced apart or insulated from the first upper power supply voltage line 210 by a constant interval or by an insulator (not shown) respectively, so that the electromagnetic waves from an external source can be shielded. FIG. 5 is a plan view of an electroluminescent display in accordance with a fourth embodiment of the present invention. The metal lines 280 are arranged inside and outside of the first upper power supply voltage line 210 to shield the electromagnetic waves from an external source. That is, a specific voltage is supplied to the metal lines 280 arranged inside and outside of the first upper power supply voltage line 210 so that the electromagnetic waves from the external source can be shielded. According to the present invention, as mentioned above, the electromagnetic waves can be shielded by the metal line arranged parallel to the first power supply voltage lines so that noise of the power supply voltage does not occur, which allows non-uniformity in brightness due to the electromagnetic waves to be improved. Although the present invention has been described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that a variety of modifications and variations may be made to the present invention without departing from the spirit or scope of the present invention defined in the appended claims, and their equivalents.

An electroluminescent display includes: a pixel region including devices arranged therein and adapted to emit light in response to a data signal; a scan driver adapted to supply a switching signal to a gate electrode of a first switching device; a data driver adapted to supply data information to a source electrode of the first switching device; a conductive power supply line adapted to supply a first power supply voltage to the pixel region, and an electromagnetic shield adapted to shield electromagnetic waves having electric or magnetic field characteristics. The electromagnetic shield is adapted to generate a second power supply voltage having a polarity opposite to that of the first power supply voltage.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit of U.S. Provisional Application No. 61/015,028, filed Dec. 19, 2007. The disclosure of this provisional application is hereby incorporated by reference. BACKGROUND OF THE INVENTION Future generations of dielectric films utilize porogens in combination with organosilicates precursors to produce porous low k films. For this purpose saturated or unsaturated hydrocarbon-based porogens are co-deposited with the organosilicate to produce the initial composite film, comprising a mixture of organosilicate precursor and organic porogen. This film is subsequently subjected to various treatment methods to decompose the porogen. During this curing process the porogen byproducts are liberated as gaseous species leaving behind an organosilicate matrix containing voids in the spaces vacated by the porogen. The resulting voids or air pockets have an intrinsic dielectric constant of unity which has the effect of decreasing the overall dielectric constant of the porous solid below that of the dense matrix material. Other areas in which organic precursors are being used in the microelectronics industry are the deposition of carbon hardmasks and the deposition of anti-reflective coatings. These films are deposited by plasma enhanced chemical vapor deposition (PECVD) using hydrocarbon precursors, especially unsaturated organic hydrocarbons. Unsaturated hydrocarbon-based materials have been evaluated for use as a porogen precursor to be used along with an appropriate organosilicate precursor for the deposition of porous low k films. However, many unsaturated hydrocarbons that are prone to polymerization will gradually degrade or polymerize at ambient temperature or at moderate temperatures that are often encountered during normal processing, purification or application of the particular chemical. The prior art discloses a variety of chemicals used to stabilize hydrocarbon-based porogens against the polymerization of olefinic hydrocarbons, including several broad classes of organic compounds such as phenols, amines, hydroxylamines, nitro compounds, quinine compounds and certain inorganic salts. An example of this would be monomers such as butadiene and isoprene which are well known to undergo gradual polymerization in storage tanks or during transportation at ambient temperatures. Some of unsaturated hydrocarbon-based precursor materials are described in U.S. Pat. No. 6,846,515, commonly assigned to the assignee of the present invention, which is incorporated by reference herein in its entirety. 2,5-Norbornadiene (NBDE) is one of the leading materials being evaluated as a precursor for porogen, carbon hardmask and antireflective coating, for the production of low dielectric constant films using chemical vapor deposition (CVD) methods. Isoprene is a promising precursor for the deposition of carbon hardmasks and antireflective coatings. However, NBDE and isoprene are thermally unstable with respect to oligomerization/polymerization. NBDE and isoprene degrade at a substantial rate at ambient temperature to form soluble NBDE and isoprene oligomeric degradation products. Isoprene is also known to undergo a relatively rapid dimerization reaction. Hence, the concentration of dissolved oligomers in NBDE and isoprene are expected to gradually increase over time during their transport and storage prior to their utilization as a precursor for dielectric materials. Furthermore, the soluble oligomers will immediately precipitate upon contact with a more polar liquid such as diethoxymethylsilane (DEMS). This instability is expected to cause precursor delivery problems and film quality issues. Chemical vendors commonly supply NBDE with 100-1000 parts per million (ppm) of 2,6-di-tert-butyl-4-methylphenol, also known as butylated hydroxytoluene or by the acronym BHT. BHT is currently used as the industry standard to slow the rate of NBDE degradation for transport and storage purposes. However, BHT has limited efficacy to suppress NBDE degradation. A recently published U.S. Patent Application 20070057235 by Teff et al. taught the use of phenolic antioxidants for the stabilization of NBDE. In order for NBDE or isoprene to be viable in a manufacturing environment it is critical that the oligomer (i.e., non-volatile residue) content is minimized to avoid processing issues and to allow manufacturers to meet the demanding film quality specifications as set by the semi-conductor industry. This invention discloses effective stabilizers which can be used to slow down the rate of degradation for the unsaturated hydrocarbons precursors, thereby mitigating the potential process and film quality issues which can result from precursor instability, thus, increasing the viability of such materials for application as precursors for porogens, carbon hardmask materials and antireflective coatings for the production of high quality low dielectric constant films. BRIEF SUMMARY OF THE INVENTION One embodiment of the present invention is a stabilized composition consisting essentially of an unsaturated hydrocarbon-based precursor material, and a stabilizer selected from the group consisting of a hydroxybenzophenone based stabilizer and a nitroxyl radical based stabilizer. Another embodiment of the present invention is a stabilized composition, consisting essentially of an unsaturated hydrocarbon-based material, at least one polar liquid and a stabilizer selected from the group consisting of a hydroxybenzophenone based stabilizer, a nitroxyl radical based stabilizer and a hydroquinone based stabilizer. Another embodiment of the present invention is a stabilized composition, consisting essentially of 2,5-Norbornadiene (NBDE), and a stabilizer selected from the group consisting of a hydroxybenzophenone based stabilizer and a nitroxyl radical based stabilizer. Yet, another embodiment of the present invention is a method for stabilizing an unsaturated hydrocarbon-based precursor material against polymerization. The method comprises providing a stabilizer selected from the group consisting of a hydroxybenzophenone based stabilizer and a nitroxyl radical based stabilizer. Yet, another embodiment of the present invention is a method for stabilizing 2,5-Norbornadiene (NBDE) against its polymerization comprising providing a stabilizer selected from the group consisting of a hydroxybenzophenone based stabilizer and a nitroxyl radical based stabilizer. Yet, another embodiment of the present invention is a method for stabilizing an unsaturated hydrocarbon-based precursor against precipitation of solids upon contact of the unsaturated hydrocarbon with at least one polar liquid, comprising (a) adding to the unsaturated hydrocarbon-based precursor a stabilizer selected from the group consisting of a hydroxybenzophenone based stabilizer, a nitroxyl radical based stabilizer and a hydroquinone based stabilizer; and (b) contacting mixture in (a) with the at least one polar liquid. For the embodiments above, the unsaturated hydrocarbon-based precursor material can have both cyclic or non-cyclic structure, wherein the cyclic structure is selected from the group consisting of (a) at least one singly or multiply unsaturated cyclic hydrocarbon having a formula C n H 2n-2x , wherein x is a number of unsaturated sites, n is from 4 to 14, the number of carbons in the cyclic structure is between 4 and 10; and (b) at least one multiply unsaturated bicyclic hydrocarbon having a formula C n H 2n-(2+2x) , wherein x is a number of unsaturated sites, n is from 4 to 14, the number of carbons in the bicyclic structure is from 4 to 12; the hydroxybenzophenone based stabilizer is represented by a structure of: wherein at least one member of the group R 1 through R 10 is hydroxyl, the remaining R 1 through R 10 is independently selected from the group consisting of hydrogen, hydroxyl, C 1 -C 18 linear, branched or cyclic alkyl, C 1 -C 18 linear, branched or cyclic alkenyl, C 1 -C 18 linear, branched or cyclic alkoxy, substituted or unsubstituted C 4 -C 8 aryl and combinations thereof; the nitroxyl radical based stabilizer is represented by a structure having at least one NO group: wherein: raised period “▪” denotes one unpaired electron; R 1 through R 4 are independently selected from a straight chained or branched, substituted or unsubstituted, alkyl or alkenyl group having a chain length sufficient to provide steric hinderance for the NO group; wherein the substituted group comprises oxygen-containing groups selected from the group consisting of hydroxyl, carbonyl, alkoxide, and carboxylic group; and R 5 and R 6 are independently selected from a straight chained or branched, a substituted or unsubstituted, alkyl group or alkenyl group. Further for some of the embodiments above, the unsaturated hydrocarbon-based precursor material is selected from the group consisting of 2,5-Norbornadiene (NBDE) and isoprene; the nitroxyl radical based stabilizer is selected from the group consisting of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (4H-TEMPO) and combinations thereof; the hydroxybenzophenone based stabilizer is selected from the group consisting of 2-hydroxy-4-methoxy-benzophenone (2H4MB), 2,4-dihydroxybenzophenone (24DHB), 2,2′-dihyroxy-4-methoxybenzophenone (22DH4MB) and combinations thereof; the hydroquinone based stabilizer is selected from the group consisting of methyl hydroquinone (MHQ), hydroquinone monomethyl ether (HQMME) and combinations thereof; and the at least one polar liquid is selected from the group consisting of diethoxymethylsilane (DEMS), isopropanol (IPA) and the mixture thereof. BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS FIG. 1 . Solids-probe mass spectrum of non-volatile residue collected from evaporation of an aged sample of NBDE. FIG. 2 . The effect of different stabilizers from the present invention on the degradation rate of NBDE at 80° C. FIG. 3 . The effect of different stabilizers on the degradation rate of NBDE at 80° C.; the stabilizers from the present invention were shown on the right and the stabilizers used in prior art were shown on the left. DETAILED DESCRIPTION OF THE INVENTION The unsaturated hydrocarbon-based precursor material can be cyclic unsaturated hydrocarbon-based. The cyclic unsaturated hydrocarbon-based precursor material can be singly or multiply unsaturated cyclic hydrocarbon having a cyclic structure and the formula C n H 2n-2x , where x is the number of unsaturated sites, n is 4 to 14, the number of carbons in the cyclic structure is between 4 and 10, and at least one singly or multiply unsaturated cyclic hydrocarbon optionally contains a plurality of simple or branched hydrocarbons substituents substituted onto the cyclic structure, and contains unsaturation inside endocyclic or on one of the hydrocarbon substituents. Examples include cyclohexene, vinylcyclohexane, dimethylcyclohexene, t-butylcyclohexene, alpha-terpinene, pinene, 1,5-dimethyl-1,5-cyclooctadiene, and vinyl-cyclohexene. The cyclic unsaturated hydrocarbon-based precursor material can also be multiply unsaturated bicyclic hydrocarbons of the general formula C n H 2n-(2+2x) where x is the number of unsaturated sites in the molecule, n=4-14, where the number of carbons in the bicyclic structure is between 4 and 12, and where there can be a plurality of simple or branched hydrocarbons substituted onto the cyclic structure. The unsaturation can be located inside endocyclic or on one of the hydrocarbon substituents to the cyclic structure. Examples include camphene, norbornene, norbornadiene, etc. The unsaturated hydrocarbon-based precursor material can also be non-cyclic, such as linear hydrocarbon-based. An example of non-cyclic unsaturated hydrocarbon-based precursor material is isoprene. Preferably, NBDE and isoprene are selected as the precursors for the production of low k dielectric materials. NBDE (2,5-Norbornadiene) is a particularly attractive precursor candidate because of its high degree of chemical unsaturation which is believed to give rise to favorable deposition properties such as high deposition rates and high utilization efficiencies. The utilization efficiency pertains to the amount of hydrocarbon porogen precursor required relative to the organosilicate precursor in order to deposit a porous low k film of a given dielectric constant. Unfortunately, the high degree of unsaturation of NBDE may also be responsible for its intrinsic thermal instability with respect to oligomerization. Laboratory evaluation has shown that NBDE degrades at ambient temperature to form soluble oligomeric species. The degradation products have been identified by solids-probe mass spectrometry to be a mixture of NBDE oligomers, including various dimers, trimers, tetramers, pentamers, hexamers, etc. shown in FIG. 1 . The degradation of NBDE raises a number of issues for its application as a precursor for making low k films. The high rate of degradation suggests that the chemical composition and physical properties of the precursor will change over time. Such changes are likely to have a significant impact on the properties of the resulting film, making it difficult for end users to produce a consistent quality film that conforms to the rigorous production specifications of thin film manufacturers. A second problem posed by the NBDE and isoprene degradation is related the chemical delivery method commonly used for such liquid precursors. Volatile liquids such as NBDE and isoprene are often delivered by a technique referred to in the industry as DLI, or direct liquid injection. For DLI systems the precursor is delivered to the tool at a precisely metered rate as a liquid through an injector port into the heated injection manifold. The manifold is operated at elevated temperature and reduced pressure to cause the precursor to rapidly vaporize. Once vaporized, the gaseous precursor is delivered to the deposition chamber. The DLI delivery method will indiscriminately transfer the NBDE or isoprene liquid along with any dissolved oligomeric degradation products to the tool. The oligomers are expected to be either less volatile or non-volatile under the temperature and pressure conditions of the heated injection manifold. The delivery of low volatility oligomeric components would result in the gradual accumulation of said species in the tool plumbing which is expected to have a detrimental impact on tool operation and/or film quality. A third possible negative consequence of using degraded NBDE is related to possible on-tool precipitation issues that may result from contact of partially degraded NBDE with a more polar chemical, such as DEMS (diethoxymethylsilane). Instantaneous precipitation of the oligomers is expected to occur if NBDE containing an appreciable concentration of dissolved oligomeric degradation products comes into contact with a substantial amount of a more polar liquid, such as an alcohol or an alkoxysilane such as DEMS. This effect is demonstrated in Examples 24, 25 and 30. The precipitation is believed to be caused by an increase in the overall polarity of the liquid blend that occurs when a substantial quantity of DEMS is added to NBDE. On-tool precipitation is expected to occur in the event that NBDE, containing oligomeric degradation products, comes into contact with a more polar component, such as DEMS, during the co-deposition of porogen and silica source materials. Such on-tool precipitation would cause increased tool down-time and/or necessitate more frequent tool preventative maintenance in order to avoid precursor plugging or flow problems. Oligomer precipitation may also cause indirect problems by adversely impacting film quality, and/or increasing on-wafer particle count, etc. In order for precursor materials to be viable in a manufacturing environment they need to satisfy practical requirements with respect to product shelf-life. The product shelf life provides the end user or manufacturer assurance that the subject chemical will meet certain minimal standards of performance if used within the time allotted by the shelf-life specification. In practice the product shelf life is often defined by the length of time a chemical will meet pre-determined purity requirements with respect to key chemical components. The rate of NBDE and isoprene degradation must be reduced to an acceptable level to ensure that they conform to minimal shelf-life criteria, and as such, will be viable in a manufacturing environment as precursors for the production of low k films. Our laboratory tests have shown that NBDE degrades in the manner previously described at a rate of ˜1.4 wt. % per year at ambient temperature, which corresponds to 1.6 ppm per hour. At 80° C. the rate of degradation increases 160-fold to 258 ppm/hr. Spiking NBDE with 200 ppm of BHT (usually provided by the chemical vendors) will reduce its rate of degradation by only 31%, such that it degrades at 179 ppm/hr at 80° C. Therefore, although BHT does slow down the degradation rate of NBDE, it does not slow it down enough to make it practical for use in the current application. These experiments are described in Examples 2-4 and summarized in Table 1 and FIGS. 2 and 3 . Our laboratory testing of the stabilizers MHQ and HQMME specified in US Patent Application 20070057235 by Teff et al. showed that they were indeed more effective than BHT for inhibiting polymerization of NBDE. For example, 200 ppm of MHQ decreased the degradation rate NBDE to 53 ppm per hour at 80° C.; 200 ppm of HQMME was slightly more effective dropping the degradation rate to 47 ppm per hour at 80° C. These represent 79% and 82% reduction, respectively, in the rate of degradation relative to the unstabilized NBDE. MHQ and HQMME were thus confirmed to be more effective than BHT for stabilizing NBDE, the same level of the latter inhibitor only decreased the NBDE degradation rate by 31% under comparable test conditions. Therefore, although MHQ and HQMME were more effective than BHT, they also have limited ability to suppress the oligomerization of NBDE, and as such, have limited utility for the stabilization of NBDE for the current application. These experiments are described in Examples 4, 7 and 9 and summarized in Table 1 and FIG. 3 . In the present invention two classes of materials are disclosed which are very effective for stabilizing NBDE. These two classes of materials are: hydroxybenzophenones and nitroxyl radicals. These two classes of inhibitors, unlike the quinones or phenolic antioxidants, do not require the presence of oxygen in order to be optimally effective. The first class of stabilizers is known as hydroxybenzophenones. The hydroxybenzophenones are known to be light stabilizers which are active UV absorbers. They are not known for their ability to suppress the oligomerization reaction of thermally unstable unsaturated hydrocarbons. This class of stabilizers is represented by the following structure: where at least one member of the group R 1 through R 10 is OH, the remaining R 1 through R 10 can each be hydrogen, hydroxyl, C 1 -C 18 linear, branched, or cyclic alkyl, C 1 -C 18 linear, branched, or cyclic alkenyl, C 1 -C 18 linear, branched, or cyclic alkoxy, or substituted or unsubstituted C 4 -C 8 aryl. Suitable examples of R 1 through R 10 may include but are not limited to hydrogen, hydroxyl, methyl, ethyl, n-propyl, n-butyl, iso-propyl, iso-butyl, tert-butyl, methoxy, ethoxy, propoxy, iso-propoxy, butoxy, iso-butoxy or tert-butoxy. Suitable examples of the hydroxybenzophenone based stabilizers may include but are not limited to 2-hydroxy-4-(n-octyloxy)benzophenone, 2-hydroxy-4-methoxybenzophenone (2H4MB), 2,4-dihydroxybenzophenone (24DHB), 2-hydroxy-4-(n-dodecyloxy)benzophenone, 2,2′-dihyroxy-4-methoxybenzophenone(22DH4MB), 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2′,4,4′-tetrahydroxybenzophenone, 4-hydroxybenzophenone and any combination thereof. Examples of preferred hydroxybenzophenones are 2-hydroxy-4-methoxybenzophenone (2H4MB), 2,4-dihydroxybenzophenone (24DHB), and 2,2′-dihyroxy-4-methoxybenzophenone (22DH4MB). The amount of the stabilizer is preferably from 1 to 5000 parts per million (ppm), more preferably 5 to 1000 ppm, and most preferable 20 to 200 ppm. In preferred embodiments, NBDE or isoprene is selected as the unsaturated hydrocarbon-based precursor for the production of low k dielectric materials; 2-hydroxy-4-methoxy-benzophenone, 2,4-dihydroxybenzophenone, or 2,2′-dihyroxy-4-methoxybenzophenone is selected as the hydroxybenzophenone based stabilizer. The amount of the stabilizer is from 20 to 200 ppm. The stabilizers in the preferred embodiments described herein, are shown to be considerably more effective at suppressing the rate of degradation than those disclosed in the prior art, and as such, increase the likelihood of the successful commercial implementation of the precursors for the production of low k dielectric materials. The second class of stabilizers known as nitroxyl radicals is represented by the following structure: Such nitroxyl radical compounds have at least one NO, wherein the raised period “▪” denotes one unpaired electron, the nitrogen atom is further bound to two carbon atoms, R 1 through R 4 are the same or different, straight chained or branched, substituted or unsubstituted, alkyl or alkenyl groups of a chain length sufficient to provide steric hinderance for the NO group, in which the substituted constituents may comprise oxygen-containing groups such as hydroxyls, carbonyls, alkoxides, carboxylic groups, including substituted groups, thereof; R 5 and R 6 are the same or different, straight chained or branched, substituted or unsubstituted, alkyl or alkenyl groups, which may be further connected by various bridging groups to form cyclic structures, such as, which may have fused to it another saturated, partially unsaturated or aromatic ring, in which any of the aforementioned cyclic or ring structures may possess ring substituents such as straight chain or branched alkyl groups or oxygen-containing groups such as hydroxyls, carbonyls, alkoxides, carboxylic groups, including substituted groups, thereof. Suitable examples of R 1 through R 4 include but are not limited to methyl, ethyl, n-propyl, n-butyl, n-pentyl, iso-propyl, iso-butyl, iso-pentyl, tert-butyl, neo-pentyl, octadecyl, propenyl, butenyl, pentenyl, and the like. Suitable examples of R 5 and R 6 include but are not limited to methyl, ethyl, n-propyl, n-butyl, n-pentyl, iso-propyl, iso-butyl, iso-pentyl, tert-butyl, neo-pentyl, octadecyl, ethenyl, propenyl, butenyl, pentenyl, or R 5 and R 6 may constitute part of a cyclic structure, such as the 6-membered piperidines, 5-membered pyrrolidones and the like, examples of which are provided below. These ring structures may be substituted. Suitable examples of the nitroxyl radical based stabilizers include but are not limited to 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (4H-TEMPO), di-tert-butyl nitroxyl, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-one, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl acetate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 2-ethylhexanoate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl stearate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl benzoate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 4-tert-butyl benzoate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)succinate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)adipate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)sebacate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)n-butylmalonate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)phthalate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)isophthalate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)terephthalate, bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)hexahydroterephthalate, N,N′-bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)adipamide, N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)-caprolactam, N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)-dodecylsuccinimide, 2,4,6-tris(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl isocyanurate, 2,4,6-tris-[N-butyl-N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl]-s-triazine, and 4,4′-ethylenebis(1-oxyl-2,2,6,6-tetramethyl piperazin-3-one). Examples of preferred nitroxyl radicals are TEMPO and 4H-TEMPO. The structures of these two compounds are shown below. The amount of the stabilizer is preferably from 1 to 5000 parts per million (ppm), more preferably 5 to 1000 ppm, and most preferable 20 to 200 ppm. In preferred embodiments, NBDE or isoprene is selected as the unsaturated hydrocarbon-based precursor for the production of low k dielectric materials and TEMPO or 4H-TEMPO is selected as the nitroxyl radical based stabilizer. The amount of the stabilizer is from 20 to 200 ppm. The stabilizers in the preferred embodiments described herein, are shown to be considerably more effective at suppressing the rate of degradation of NBDE than those disclosed in the prior art, and as such, increase the likelihood of its commercial implementation for the production of porous low k dielectric materials. WORKING EXAMPLES In order to more fully describe the present invention, the following examples are presented which are intended to be merely illustrative and not in any sense limitative of the invention. NBDE degrades at a substantial rate at ambient temperature forming soluble oligomeric byproducts. The degradation may or may not result in the discoloration of the NBDE liquid. The extent of degradation is assessed by determining the concentration of oligomers in the NBDE liquid. However, gas chromatography, the most common chemical analysis method used for organic liquids, is not an effective method for quantifying the amount of oligomers in NBDE solution. The oligomers cannot be accurately quantified by GC because they are reactive and, as such, they are prone to further oligomerization. They are also generally non-volatile because of their high molecular weight causing them to elute from the GC column only after very long retention times or perhaps not at all. A non-volatile residue test has been developed to reliably measure the amount of oligomers in NBDE solution. To perform this evaluation NBDE is evaporated by purging the NBDE container with a high purity inert gas, such as helium, leaving behind the non-volatile residue components. The container may be heated slightly during the evaporation step in order to obtain a stable final weight. The weight of the non-volatile residue, thus determined, is used as a measure of the amount of oligomers in solution, and hence, an indication of the extent of degradation of NBDE. This general method is described in further detail in Example 1. Unstabilized NBDE degrades at a rate of approximately 1.4% per year at ambient temperature. This corresponds to about 270 ppm per week or about 1.6 ppm per hour. In order to assess the relative degradation within a practical period of time, various samples of unstabilized and stabilized NBDE were subjected to standardized accelerated aging test conditions. This test consisted of distilling the NBDE to remove any non-volatile degradation products. Within 24 hours the distilled NBDE was placed into quartz containers as described below, and heated to 60-80° C. for 6-7 days. After this time the containers were cooled to room temperature and the amount of degradation was determined. In this manner various stabilizers were assessed according to their relative ability to suppress the degradation of NBDE. Examples 2-23, illustrate the measurement of non-volatile residue (i.e., the extent of degradation) for various samples of neat and stabilized NBDE. The NBDE used in Example 2 was aged at room temperature. The NBDE evaluated in Examples 3-23 was subjected to accelerated aging conditions as described herein. Example 1 Residue Evaluation of Recently Distilled NBDE A sample of NBDE was flash distilled to remove non-volatile impurities using a rotary-evaporator. The distilled material was analyzed by GC to have a nominal purity of 99.4%. The tare weight of an empty, clean 1.2 liter quartz bubbler was recorded after evacuation. The bubbler was previously equipped with gas inlet and outlet ports, each fitted with a Teflon valve. The bubbler inlet port had a dip-tube that extends to within ⅛″ of the base of the container. About 600 g of NBDE was added to the quartz bubbler within a nitrogen-containing dry box. The bubbler was re-weighed to determine the weight of the NBDE. A cylinder of research grade He was connected to the bubbler inlet line. The bubbler temperature was increased to 35° C. to increase the vapor pressure of the NBDE. He was purged through the bubbler at a flow rate of 3.0 SLPM (standard liters per minute) for 4 hours to evaporate the NBDE. At this time the bubbler temperature was raised to 80° C. and the bubbler was evacuated for 2.0 hours to achieve a stable weight. This experiment was done in duplicate. The weights of the non-volatile residue for the two runs were 0.59 g and <0.01 g, corresponding to an average residue of 0.05 wt. %. The experimental results are summarized in Table 1. Example 2 Evaluation of the Degradation Rate of NBDE Stored at Ambient Temperature A 13.0 liter sample of NBDE was purified by atmospheric distillation. The distilled sample was analyzed by GC to have a nominal purity of 99.4%. The sample was stored in a chemical cabinet indoors for a total of 287 days. At this time approximately 200 g of NBDE was loaded into a pre-cleaned, pre-tared bubbler as described in Example 1. The bubbler was subjected to 3.0 SLPM at 35° C. for 4.0 hours to evaporate the NBDE. The bubbler temperature was raised to 80° C. and the bubbler was evacuated for 2.0 hours to achieve a stable weight. The final weight of the bubbler was recorded after the evacuation step to determine the weight of the non-volatile residue. This experiment was done in duplicate. The weights of the non-volatile residue for the two runs were 2.29 g and 2.24 g, corresponding to an average residue of 1.12 wt. %. This is equivalent to a degradation rate of 1.63 ppm per hour based on the weight of the residue and the 287 days of aging. The experimental results are summarized in Table 1. Example 3 Evaluation of the Degradation Rate of Unstabilized NBDE Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. Approximately 150-200 g of the distilled NBDE was loaded into a cleaned, pre-tared bubbler as described in Example 1. The bubbler was placed into an oven and held at 80° C. for 7 days. The temperature of 80° C. was chosen for this study for two reasons: (1) 7 days at 80° C. is intended to simulate the amount of degradation that would occur if the sample were allowed to age at ambient temperature for 1 year, assuming that the degradation rate follows a simple Arrhenius type behavior of doubling for every temperature increase of 10° C.; and (2) 80° C. is a common temperature for the heated manifold used to vaporize precursors prior to the mixing bowl and/or deposition chamber in chemical vapor deposition hardware. The quartz bubbler was removed from the 80° C. oven after 7 days. The bubbler was held at 35° C. while purging with 3 SLPM of He for 6 hours. At this time the bubbler temperature was raised to 80° C. and the bubbler was evacuated for 2.0 hours to achieve a stable weight. The final weight of the bubbler was recorded after the evacuation step to determine the weight of the non-volatile residue. This experiment was run a total of 6 times, since it was used as the “control” for the evaluation of various stabilizers. The average non-volatile residue for these runs was 4.33 wt. %, corresponding to a degradation rate of 258 ppm per hour at 80° C. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 4 Evaluation of the Degradation Rate of NBDE Stabilized with 200 ppm of BHT Using Accelerated Aging Conditions Commercial samples of NBDE are typically stabilized with BHT. In this example, comparable experiments were carried out to evaluate the degradation rate of NBDE when using BHT as the stabilizer. A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of BHT stabilizer. This is a common level of BHT present in NBDE as provided by chemical suppliers. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 2.64 wt. %, corresponding to a degradation rate of 179 ppm per hour at 80° C. This represents a 31% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIG. 3 . Example 5 Evaluation of the Degradation Rate of NBDE Stabilized with 200 ppm of TBC using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of TBC (p-tert-butylcatechol) stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 2.64 wt. %, corresponding to a degradation rate of 157 ppm per hour at 80° C. This represents a 39.1% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIG. 3 . Example 6 Evaluation of the Degradation Rate of NBDE Stabilized with 200 ppm of TBC Containing 8 Volume % Oxygen in the Headspace The utilization of oxygen in combination with the stabilizer is typically done to enhance stability during chemical transport and storage. This is accomplished by storing the polymerizable chemical in a container in which oxygen comprises 5-20% of the gas in the headspace above the stored liquid. In this manner, the oxygen dissolves in the hydrocarbon liquid and thus is available to facilitate the inhibition of the polymerization reaction. The oxygen can be diluted with an inert gas such as nitrogen or helium to create the desired oxygen content in the headspace gas. This is commonly done to ensure a non-flammable environment for the material being stabilized. Alternatively, an appropriate amount of ambient air can be introduced into the container in order to establish the desired gaseous oxygen content. A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of TBC stabilizer. Approximately 170 g (˜200 ml) of TBC-stabilized NBDE was added to a 500 ml quartz bubbler within a nitrogen dry box as described in Example 1. The bubbler was removed from the dry box. Twenty five sccm (standard cubic centimeters) of nitrogen was removed from the bubbler headspace using a syringe. Twenty five sccm of research grade oxygen was subsequently added to the headspace by reinjecting the gas into the bubbler. The NBDE bubbler thus prepared had nominally 8 volume percent oxygen in the headspace. The sample was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.97 wt. %, corresponding to a degradation rate of 57 ppm per hour at 80° C. This represents a 77.7% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIG. 3 . Example 7 Evaluation of the Degradation Rate of NBDE Stabilized with 200 ppm of MHQ Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of MHQ (methyl hydroquinone) stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.79 wt. %, corresponding to a degradation rate of 47 ppm per hour at 80° C. This represents an 81.7% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIG. 3 Example 8 Evaluation of the Degradation Rate of NBDE Stabilized with 200 ppm of MHQ Containing 5 Volume % Oxygen in the Headspace A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of MHQ stabilizer. Approximately 150 g (˜180 ml) of MHQ-stabilized NBDE was added to a 500 ml quartz bubbler within a nitrogen dry box as described in Example 1. The bubbler was removed from the dry box. Sixteen sccm (standard cubic centimeters) of nitrogen was removed from the bubbler headspace using a syringe. Sixteen sccm of research grade oxygen was subsequently added to the headspace by reinjecting the gas into the bubbler. The NBDE bubbler thus prepared had nominally 5 volume percent oxygen in the headspace. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.39 wt. %, corresponding to a degradation rate of 23 ppm per hour at 80° C. This represents a 91.1% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIG. 3 . Example 9 Evaluation of the Degradation Rate of NBDE Stabilized with 200 ppm of HQMME Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of HQMME (hydroquinone monomethyl ether) stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.90 wt. %, corresponding to a degradation rate of 53 ppm per hour at 80° C. This represents a 79.3% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIG. 3 . Example 10 Evaluation of the Degradation Rate of NBDE Stabilized with 50 ppm of HQMME Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 50 ppm by weight of HQMME stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating it to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate, using 111 g and 130 g of NBDE for the two runs. The average non-volatile residue for these two runs was 1.42 wt. %, corresponding to a degradation rate of 84 ppm per hour at 80° C. This represents a 67.3% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIG. 3 . Example 11 Evaluation of the Degradation Rate of NBDE Stabilized with 500 ppm of HQMME Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 500 ppm by weight of HQMME stabilizer. The stabilized NBDE (209 g) was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. The non-volatile residue for this run was measured to be 1.73 wt. %, corresponding to a degradation rate of 103 ppm per hour at 80° C. This represents a 60.1% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIG. 3 . Example 12 Evaluation of the Degradation Rate of NBDE Stabilized with 200 ppm of 2-hydroxy-4-methoxybenzophenone (2H4MB) Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of 2H4MB stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.33 wt. %, corresponding to a degradation rate of 20 ppm per hour at 80° C. This represents a 92.3% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 13 Evaluation of the Degradation Rate of NBDE Stabilized with 200 ppm of 2,4-dihydroxybenzophenone (24DHB) Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of 24DHB stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.21 wt. %, corresponding to a degradation rate of 12 ppm per hour at 80° C. This represents a 95.2% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 14 Evaluation of the Degradation Rate of NBDE Stabilized with 200 ppm of 2,2′-dihyroxy-4-methoxybenzophenone (22DH4MB) Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of 22DH4MB stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.21 wt. %, corresponding to a degradation rate of 13 ppm per hour at 80° C. This represents a 95.1% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 15 Evaluation of the Degradation Rate of NBDE at 80° C. Stabilized with 200 ppm of TEMPO Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.02 wt. %, corresponding to a degradation rate of 1 ppm per hour at 80° C. This represents a 99.4% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 16 Evaluation of the Degradation Rate of NBDE at 80° C. Stabilized with 50 ppm of TEMPO Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 50 ppm by weight of TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.04 wt. %, corresponding to a degradation rate of 3 ppm per hour at 80° C. This represents a 99.0% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 17 Evaluation of the Degradation Rate of NBDE at 80° C. Stabilized with 20 ppm of TEMPO Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 20 ppm by weight of TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.10 wt. %, corresponding to a degradation rate of 6 ppm per hour at 80° C. This represents a 97.7% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 18 Evaluation of the Degradation Rate of NBDE at 80° C. Stabilized with 5 ppm of TEMPO Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 5 ppm by weight of TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 6 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. The non-volatile residue for this run was 0.13 wt. %, corresponding to a degradation rate of 9 ppm per hour at 80° C. This represents a 96.5% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 19 Evaluation of the Degradation Rate of NBDE at 80° C. Stabilized with 200 ppm of 4H-TEMPO Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of 4H-TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 6 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.10 wt. %, corresponding to a degradation rate of 7 ppm per hour at 80° C. This represents a 97.2% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 20 Evaluation of the Degradation Rate of NBDE at 80° C. Stabilized with 20 ppm of 4H-TEMPO Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 20 ppm by weight of 4H-TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 6 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.08 wt. %, corresponding to a degradation rate of 6 ppm per hour at 80° C. This represents a 97.8% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 21 Evaluation of the Degradation Rate of NBDE at 60° C. Stabilized with 200 ppm of TEMPO Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 200 ppm by weight of TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 60° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.02 wt. %, corresponding to a degradation rate of 1 ppm per hour at 80° C. This represents a 99.5% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 22 Evaluation of the Degradation Rate of NBDE at 60° C. Stabilized with 50 ppm of TEMPO Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 50 ppm by weight of TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 60° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.06 wt. %, corresponding to a degradation rate of 3 ppm per hour at 80° C. This represents a 98.7% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 23 Evaluation of the Degradation Rate of NBDE at 60° C. Stabilized with 20 ppm of TEMPO Using Accelerated Aging Conditions A sample of NBDE was flash distilled to remove non-volatile impurities as described in Example 1. The distilled NBDE was spiked with 20 ppm by weight of TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 60° C. for 7 days, followed by He purge to determine the amount of non-volatile residue as described in Example 3. This test was run in duplicate. The average non-volatile residue for these two runs was 0.03 wt. %, corresponding to a degradation rate of 2 ppm per hour at 80° C. This represents a 99.3% decrease in the degradation rate relative to unstabilized NBDE. The experimental results are summarized in Table 1 and FIGS. 2 and 3 . Example 24 Mixing of Aged Unstabilized NBDE with DEMS as a Polar Liquid This example illustrates the forced precipitation of the non-polar oligomers by gradually increasing the net polarity of the liquid. Working in a nitrogen containing dry box, 102.0 g of unstabilized NBDE which had aged for 287 days at ambient temperature was placed into a 200 ml Pyrex bottle. The same weight of DEMS was placed into a second similar Pyrex bottle. Both the NBDE and DEMS were clear, colorless liquids with no indication of precipitate or residue. The two liquids were combined by slowly adding the DEMS to the NBDE. After the addition of about 20 g of DEMS a small amount of a white permanent precipitate was evident in the DEMS-NBDE mixture. This precipitate grew more prominent as the balance of the DEMS was added to the NBDE. The white precipitate gradually settled to the bottom of the Pyrex container. The contents of the Pyrex container were transferred to a Schlenk flask. The flask was subjected to dynamic vacuum for 4 hours at room temperature to remove the DEMS and NBDE liquids, leaving behind 1.20 g. of white solid. This weight of non-volatile solid residue corresponds to 1.18 wt. % based on the initial weight of the NBDE. This is equivalent to a degradation rate of 1.71 ppm per hour at ambient temperature. The weight percent residue determined by this route is in excellent agreement with the amount of residue measured by the He purge non-volatile residue test described in FIGS. 2 and 3 . Example 25 Evaluation of Precipitation in the Mixing of Aged Unstabilized NBDE with DEMS NBDE was flash distilled to remove non-volatile impurities using a rotary-evaporator as described in Example 1. The distilled material was analyzed by GC to have a nominal purity of 99.4%. No stabilizer was added to the NBDE. The unstabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days in quartz bubblers as described in Example 3. This test was done in duplicate using 87.64 g and 90.23 g of NBDE for the two runs. Upon removal of the two bubblers from the oven at 80° C. there was no visible sign of precipitation or discoloration of the NBDE liquid. After allowing the NBDE to cool to room temperature, DEMS was slowly added to each bubbler through the inlet line in an attempt to force the precipitation of dissolved oligomeric degradation products. The first permanent precipitate was visible after the addition of 35-40 g of DEMS to the unstabilized NBDE. Additional DEMS was added until each bubbler contained a 1:1 weight ratio of NBDE to DEMS. At this point a large amount of white precipitate was evident, indicating that a substantial amount of oligomeric degradation products were present. The bubblers were subjected to dynamic vacuum for 4 hours at 30° C., followed by a final evacuation for 1 hour at 80° C., leaving behind 0.73 g and 1.04 g of white solid residue. This amounts to an average non-volatile residue of 1.00% based on the initial weight of the NBDE, corresponding to a degradation rate of 59 ppm per hour at 80° C. Example 26 Evaluation of Reduction of Precipitation in the Mixing of Aged NBDE with DEMS Stabilized with 200 ppm of HQMME NBDE was flash distilled to remove non-volatile impurities using a rotary-evaporator as described in Example 1. The distilled material was analyzed by GC to have a nominal purity of 99.4%. The NBDE was spiked with 200 ppm by weight of HQMME stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days in quartz bubblers as described in Example 3. This test was done in duplicate using 98.77 g and 71.93 g of NBDE for the two runs. Upon removal of the two bubblers from the oven at 80° C. there was no visible sign of precipitation or discoloration of the NBDE liquid. After allowing the NBDE to cool to room temperature, DEMS was slowly added to each bubbler through the inlet line in an attempt to force the precipitation of dissolved oligomeric degradation products. The addition of DEMS continued until each bubbler contained a 1:1 weight ratio of NBDE to DEMS. This resulted in a faint, cloudy solution in each of the two bubblers, indicating precipitation of a small amount of oligomers from solution. The bubblers were subjected to dynamic vacuum for 4 hours at 30° C., followed by a final evacuation for 1 hour at 80° C., leaving behind 0.17 g and 0.14 g of white solid residue. This amounts to an average non-volatile residue of 0.18 wt. % based on the initial weight of the NBDE, corresponding to a degradation rate of 11 ppm per hour at 80° C. This represents an 82% decrease in the degradation rate relative to forced precipitation of the unstabilized NBDE subjected to identical ageing conditions as described in Example 13. The experimental results are summarized in Table 2. Example 27 Evaluation of Reduction of Precipitation in the Mixing of Aged NBDE with DEMS Stabilized with 200 ppm of MHQ NBDE was flash distilled to remove non-volatile impurities using a rotary-evaporator as described in Example 1. The distilled material was analyzed by GC to have a nominal purity of 99.4%. The NBDE was spiked with 200 ppm by weight of MHQ stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days in quartz bubblers as described in Example 3. This test was done in duplicate using 105.17 g and 98.53 g of NBDE for the two runs. Upon removal of the two bubblers from the oven at 80° C. there was no visible sign of precipitation or discoloration of the NBDE liquid. After allowing the NBDE to cool to room temperature, DEMS was slowly added to each bubbler through the inlet line in an attempt to force the precipitation of dissolved oligomeric degradation products. The addition of DEMS continued until each bubbler contained a 1:1 weight ratio of NBDE to DEMS. The resulting NBDE-DEMS blend remained clear and colorless with no visible indication of precipitation. The bubblers were subjected to dynamic vacuum for 4 hours at 30° C., followed by a final evacuation for 1 hour at 80° C., leaving behind 0.10 g and 0.03 g of white solid residue. This amounts to an average non-volatile residue of 0.06 wt. % based on the initial weight of the NBDE, corresponding to a degradation rate of 4 ppm per hour. This represents a 94% decrease in the degradation rate relative to forced precipitation of the unstabilized NBDE subjected to identical ageing conditions as described in Example 13. The experimental results are summarized in Table 2. Example 28 Evaluation of Reduction of Precipitation in the Mixing of Aged NBDE with DEMS Stabilized with 200 ppm 22DH4MB NBDE was flash distilled to remove non-volatile impurities using a rotary-evaporator as described in Example 1. The distilled material was analyzed by GC to have a nominal purity of 99.4%. The NBDE was spiked with 200 ppm by weight of 22DH4MB stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days in quartz bubblers as described in Example 3. This test was done in duplicate using 111.53 g and 106.22 g of NBDE for the two runs. Upon removal of the two bubblers from the oven at 80° C. there was no visible sign of precipitation or discoloration of the NBDE liquid. After allowing the NBDE to cool to room temperature, DEMS was slowly added to each bubbler through the inlet port in an attempt to force the precipitation of dissolved oligomeric degradation products. The addition of DEMS continued until each bubbler contained a 1:1 weight ratio of NBDE to DEMS. This resulted in a cloudy solution in each of the two bubblers, indicating some amount of precipitation of oligomers from solution. The bubblers were subjected to dynamic vacuum for 4 hours at 30° C., followed by a final evacuation for 1 hour at 80° C., leaving behind 0.51 g and 0.65 g of white solid residue. This equates to an average non-volatile residue of 0.53 wt. % based on the initial weight of the NBDE, corresponding to a degradation rate of 32 ppm per hour at 80° C. This represents a 46% decrease in the degradation rate relative to forced precipitation of the unstabilized NBDE subjected to identical ageing conditions as described in Example 25. The experimental results are summarized in Table 2. Example 29 Evaluation of Reduction of Precipitation in the Mixing of Aged NBDE with DEMS Stabilized with 200 ppm of TEMPO NBDE was flash distilled to remove non-volatile impurities using a rotary-evaporator as described in Example 1. The distilled material was analyzed by GC to have a nominal purity of 99.4%. The NBDE was spiked with 200 ppm by weight of TEMPO stabilizer. The stabilized NBDE was subjected to accelerated aging test conditions by heating to 80° C. for 7 days in quartz bubblers as described in Example 3. This test was done in duplicate using 94.77 g and 110.56 g of NBDE for the two runs. Upon removal of the two bubblers from the oven at 80° C. there was no visible sign of precipitation. After allowing the NBDE to cool to room temperature, DEMS was slowly added to each bubbler through the inlet port in an attempt to force the precipitation of dissolved oligomeric degradation products. The addition of DEMS continued until each bubbler contained a 1:1 weight ratio of NBDE to DEMS. The resulting NBDE-DEMS blend remained clear with no visible indication of cloudiness or precipitation. The bubblers were subjected to dynamic vacuum for 4 hours at 30° C., followed by a final evacuation for 1 hour at 80° C., leaving behind 0.11 g and 0.10 g of yellowish residue. This equates to an average non-volatile residue of 0.10 wt. % based on the initial weight of the NBDE, corresponding to a degradation rate of 6 ppm per hour. This represents a 90% decrease in the degradation rate relative to forced precipitation of the unstabilized NBDE subjected to identical ageing conditions as described in Example 25. The experimental results are summarized in Table 2. Example 30 Mixing of Aged Unstabilized NBDE with a Polar Solvent Similar to Example 24, working in a nitrogen containing dry box, 2.0 ml (1.6 g) of isopropyl alcohol (IPA) was slowly added to 2.0 ml of the unstabilized NBDE (1.7 g). The NBDE used for this test was aged for 287 days at ambient temperature. Both the NBDE and IPA used for this experiment were clear, colorless liquids with no indication of precipitate or residue. An immediate permanent precipitate was noticed after the addition of the first few drops of isopropanol to the aged NBDE. The amount of precipitation became more pronounced as the remainder of the 2.0 ml of IPA was added. This example again demonstrates the precipitation of the largely non-polar oligomers caused by increasing the net polarity of the solvent. Example 31 Characterization of NBDE Degradation Products A 50 g sample of unstabilized NBDE which had been stored at room temperature for several months was placed into a 100 ml quartz ampoule equipped with a Teflon valve. The ampoule was evacuated at room temperature for 2 hours to generate an off-white non-volatile residue. The resulting solid was collected and analyzed by solids-probe mass spectrometry. The analysis confirmed the presence of various oligomers of NBDE, including the dimer, trimer, tetramer, pentamer, hexamer, etc. The solids-probe mass spectrum from this analysis is shown in FIG. 1 . TABLE 1 Summary of the non-volatile residue test results described in Examples 1-23. Wt. of Degradation Normalized Reduction of Example NBDE NVR (non-volatile residue) rate degradation degradation No. Stabilizer Aging Conditions (g) (g) (wt. %) avg (wt. %) (ppm/hr) rate rate (%) 1 no stabilizer none 619.32 0.59 0.10 0.05 NA NA NA 582.70 0.00 0.00 2 no stabilizer 287 days at RT 202.46 2.29 1.13 1.12 1.63 NA NA 202.15 2.24 1.11 3 no stabilizer 7 days at 80° C. 148.35 6.25 4.21 4.33 258 1.000 0.0 149.79 6.06 4.05 103.87 5.59 5.38 118.95 5.94 4.99 148.30 5.31 3.58 149.15 5.65 3.79 4 200 ppm 7 days at 80° C. 149.44 4.6 3.08 3.01 179 0.690 31.0 BHT 163.89 4.83 2.95 5 200 ppm 7 days at 80° C. 155.43 3.43 2.21 2.64 157 0.609 39.1 TBC 154.63 4.75 3.07 6 200 ppm 7 days at 80° C. 174.10 1.51 0.87 0.97 57 0.223 77.7 TBC with O 2 164.59 1.75 1.06 7 200 ppm 7 days at 80° C. 154.95 1.14 0.74 0.79 47 0.183 81.7 MHQ 146.14 1.24 0.85 8 200 ppm 7 days at 80° C. 152.93 0.52 0.34 0.39 23 0.089 91.1 MHQ with O 2 145.57 0.63 0.43 9 200 ppm 7 days at 80° C. 106.26 1.00 0.94 0.90 53 0.207 79.3 HQMME 114.82 0.98 0.85 10 50 ppm 7 days at 80° C. 110.75 1.20 1.08 1.42 84 0.327 67.3 HQMME 130.23 2.28 1.75 11 500 ppm 7 days at 80° C. 209.14 3.62 1.73 1.73 103 0.399 60.1 HQMME 12 200 ppm 7 days at 80° C. 147.78 0.59 0.40 0.33 20 0.077 92.3 2H4MB 154.91 0.41 0.26 13 200 ppm 7 days at 80° C. 149.14 0.32 0.21 0.21 12 0.048 95.2 24DHB 145.25 0.29 0.20 14 200 ppm 7 days at 80° C. 152.00 0.31 0.20 0.21 13 0.049 95.1 22DH4MB 165.88 0.37 0.22 15 200 ppm 7 days at 80° C. 140.51 0.04 0.03 0.02 1 0.006 99.4 TEMPO 148.59 0.03 0.02 16  50 ppm 7 days at 80° C. 143.38 0.08 0.06 0.04 3 0.010 99.0 TEMPO 139.63 0.04 0.03 17  20 ppm 7 days at 80° C. 130.45 0.17 0.13 0.10 6 0.023 97.7 TEMPO 144.58 0.10 0.07 18  5 ppm 6 days at 80° C. 68.82 0.09 0.13 0.13 9 0.035 96.5 TEMPO 19 200 ppm 6 days at 80° C. 137.56 0.12 0.09 0.10 7 0.028 97.2 4H-TEMPO 116.36 0.14 0.12 20  20 ppm 6 days at 80° C. 130.98 0.15 0.11 0.08 6 0.022 97.8 4H-TEMPO 102.25 0.05 0.05 21 200 ppm 7 days at 60° C. 130.38 0.03 0.02 0.02 1 0.005 99.5 TEMPO 172.71 0.03 0.02 22  50 ppm 7 days at 60° C. 147.10 0.12 0.08 0.06 3 0.013 98.7 TEMPO 155.90 0.05 0.03 23  20 ppm 7 days at 60° C. 154.92 0.03 0.02 0.03 2 0.007 99.3 TEMPO 167.67 0.07 0.04 TABLE 2 Summary of the non-volatile residue test results from the forced precipitation experiments described in Examples 25-29. NVR Wt. of (non-volatile residue) Degradation Normalized Reduction of Example Ageing Wt. of NBDE DEMS avg rate degradation degradation No. Stabilizer Conditions (g) added (g) (g) (wt. %) (wt. %) (ppm/hr) rate rate (%) 25 none 7 days at 87.64 87.64 1.04 1.19 1.00 59 1.00 0.00 80° C. 90.23 90.23 0.73 0.81 26 200 ppm 7 days at 98.77 98.77 0.17 0.17 0.18 11 0.18 0.82 HQMME 80° C. 71.93 71.93 0.14 0.19 27 200 ppm 7 days at 94.77 94.77 0.10 0.10 0.06 4 0.06 0.94 MHQ 80° C. 110.56 110.56 0.03 0.03 28 200 ppm 7 days at 111.53 111.53 0.51 0.46 0.53 32 0.54 0.46 22DH4MB 80° C. 106.22 106.22 0.65 0.61 29 200 ppm 7 days at 94.77 94.77 0.11 0.12 0.10 6 0.10 0.90 TEMPO 80° C. 110.56 110.56 0.10 0.09 The embodiments of the present invention listed above, including the working examples, are exemplary of numerous embodiments that may be made of the present invention. It is contemplated that numerous other configurations of the process may be used, and the materials used in the process may be selected from numerous materials other than those specifically disclosed. In short, the present invention has been set forth with regard to particular embodiments, but the full scope of the present invention should be ascertained from the claims as follow.

A stabilized composition consists essentially of unsaturated hydrocarbon-based materials, and a stabilizer selected from the group consisting of hydroxybenzophenone and a nitroxyl radical based stabilizer. A method for stabilizing unsaturated hydrocarbon-based precursor material against the polymerization comprises providing a stabilizer selected from the group consisting of a hydroxybenzophenone and a nitroxyl radical based stabilizer.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates generally to devices that propel forcibly into the air spherical objects such as tennis balls or the like for practice or training purposes. In a more particular sense, the invention relates to means for imparting oscillatory motion to the discharge barrel of a propulsion device of the type stated about an axis that, if not completely vertical, has at least a vertical component. The invention is directed to a programming-type improvement in the means for creating oscillating motion of the discharge barrel whereby to time the oscillation and the extent of angular travel thereof in relation to the successive discharge of the balls during the normal rotation of the distributor or feed magazine. 2. Description of the Prior Art Tennis ball propulsion devices, for use as training aids, are of course very well known. A typical propulsion device of the type stated may be seen in U.S. Pat. No. 4,027,646 issued June 7, 1977. In such devices, there is a hopper, a rotary feed magazine or distributor having a plurality of angularly spaced ball-receiving openings or sleeves, and a conduit that extends from the distributor location to the outlet of the device. Passage of a ball from the distributor through said conduit occurs within a pressurizing chamber, in such fashion that the balls are successively fed through the conduit. Pressure is built up behind each of them, until the pressure reaches a value such as to cause the ball to be forcibly discharged. In the prior art, various means have heretofore been devised for changing or varying the path in which the successively propelled objects will be directed. It is known, for example, to cause the discharge barrel of such a device to be oscillated, that is, moved in a continuous back-and-forth or side-to-side motion, so that the user will be required to run back-and-forth across the tennis court, to return each ball, thereby to obtain practice in executing forehand as well as backhand strokes, increase his or her stamina, and otherwise obtain added benefits from the use of the propulsion device. See for example, Sweeton et al U.S. Pat. No. 4,006,726 issued to the assignee of the present application, and the patents cited therein. The prior art devices have been effective in respect to achieving the broad objects of varying the paths along which the tennis balls or other spherical objects are discharged. However, the prior art has had certain disadvantages, including, for example, the provision of oscillatory motion only through the medium of expensive electrical, electronic, or complex mechanical devices. Further, in the prior art such devices have in many instances been required to be built into the complete device, in such fashion that the user would be prevented from manufacturing, with the same components, both standard and programmed oscillating type discharge mechanisms. In still other prior art devices, it has not been possible for a user to adjust, with maximum speed and ease, the width of the oscillating path in which the discharge end of the barrel is to travel. And in yet other cases the user is prevented from disengaging the oscillating mechanism except with considerable difficulty. Thus, the prior art has broadly suggested the concept of timing oscillation of a discharge barrel in relation to the feeding of balls into the propulsion device, but heretofore, so far as is known, the prior art has not suggested a mechanical linkage between the ball feeding and the discharge mechanisms, such as to optionally connect or disconnect the oscillation-producing means, adjust swiftly and easily the extent of oscillating travel in relation to the quantum and frequency of ball delivery, and, in general, facilitate the manufacture of propulsion devices of this type so as to incorporate an oscillating mechanism that is inexpensive, simple, and trouble free, and that can be either incorporated in or left out of the propulsion device, according to the desires of the manufacturer and without changing in either instance the design or assembly of the basic propulsion device. SUMMARY OF THE INVENTION Summarized briefly, the improvement comprising the present invention is incorporated in a propulsion device of basically known or conventional design and construction. Such devices include a portable housing, containing a pressurizing chamber and a ball feed hopper. A rotary distributor has a series of angularly spaced ball-receiving sleeves, through which the balls pass from the hopper. As the distributor rotates, it passes over a feed opening extending into the pressurizing chamber, so that the balls are successively delivered from the distributor or magazine into the chamber. Within the pressurizing chamber, they are directed in following order into a receiver, for subsequent discharge through the barrel. Means are provided within the discharge path to temporarily arrest each ball, in a sealable fashion, so as to cause pressure to build up within the pressurizing chamber. When the pressure reaches a predetermined value, the ball is forcibly moved past the arresting device or means, and is discharged under pressure from the barrel. The improved device constituting the present invention incorporates a shaft extension projecting upwardly from the distributor. Secured to the upper end of the extension is a member, having a plurality of openings spaced different radial distances from the axis of rotation of the member. An elongated link has a distal end overlying the member, this end of the link being formed with a longitudinal slot. A drop pin is removably positioned through the slot, to engage in any opening of the member selected by the user. The other end of the link is connected to a barrel support bracket, which is pivotally mounted upon the housing of the device for swinging movement about an axis which, if not completely vertical, at least has a vertical component. By selecting a particular opening of the member for insertion of the drop pin, the range of oscillatory motion of the barrel support bracket, and hence of the barrel itself, is adjusted. In other words, the closer the selected opening to the axis of member rotation, the narrower the width of the oscillatory cycle of the barrel. The entire oscillating mechanism can be disconnected merely by removing the drop pin or locating it in an opening of the member coincident with its axis of rotation. If it is desired to manufacture the device without the oscillating mechanism, one may simply leave off the extension shaft, member, and link, while maintaining the barrel support bracket against pivotal movement. BRIEF DESCRIPTION OF THE DRAWINGS While the invention is particularly pointed out and distinctly claimed in the concluding portions herein, a preferred embodiment is set forth in the following detailed description which may be best understood when read in connection with the accompanying drawings, in which: FIG. 1 is a top plan view of a ball propulsion device incorporating the improvement that comprises the present invention; FIG. 2 is a longitudinal, vertical section through the device, taken substantially on line 2--2 of FIG. 1, the chain dotted and dashed lines indicating alternative barrel positions and barrel types; FIG. 3 is an enlarged, fragmentary top plan view of the device as seen from the line 3--3 of FIG. 2, the chain dotted lines indicating three different positions to which the barrel moves during its oscillatory travel; FIG. 4 is a fragmentary, longitudinal sectional view substantially on line 4--4 of FIG. 3, on the same scale as FIG. 3; FIG. 5 is a still further enlarged, top plan view of the motion translating rotary member, per se; FIG. 6 is a still further enlarged, exploded perspective view of the motion translating mechanism or linkage, per se; FIGS. 7a and 7b are diagrammatic representations of a practice area, illustrating the device as it appears when in use; FIG. 8 is a transverse, vertical sectional view on the same scale as FIGS. 3 and 4, taken substantially on line 8--8 of FIG. 2; and FIG. 9 is a top plan view of a modified form of rotary member capable of being substituted for that illustrated in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing in detail, the reference numeral 10 has been generally applied to a ball propulsion machine or device having the improvement comprising the present invention. A machine of this type, conventionally, includes a hollow housing or support frame 12. This may be wheeled as at 14. It may have a handle 16 to facilitate movement to a desired location, and may be provided with a skid or frame member 18 providing a stable support for the device when in use. When in use, the device appears as in FIG. 2. The machine conventionally includes a divider 20. This separates the machine into a pressurizing chamber 22 and an upwardly opening hopper 24 for tennis balls B or other spherical objects to be propelled. Within the pressurizing chamber, there is provided a transverse partition 26 near the forward end of the chamber. Mounted upon the partition is a blower 28 extending rearwardly within the pressurizing chamber 22. An air inlet 30 is disposed in communication with an air intake chamber 31. Chamber 31 is defined between the partition 26 and the front wall of the housing 12. Air entering through the opening 30 is drawn by the blower 28 into the pressurizing chamber, and is discharged toward the rear end of the chamber through the provision of a large diameter blower outlet tube 32. Tube 32 may as illustrated be mounted directly upon the blower within the pressurizing chamber. A rotary, generally flat, circular distributor or magazine 34 is provided. Distributor 34 is mounted at the bottom of the feed hopper directly above the divider 20. The distributor is mounted for rotation upon a shaft 35 supported in the housing and extending through divider 20. The distributor may be integral or is otherwise made rotatable with an upstanding projection or boss 36 of cylindrical form. Boss 36 has a plurality of angularly and uniformly spaced radially projecting agitator ribs 38. These serve to prevent "bridging" of the tennis balls above the distributor. They assure that the several angularly spaced ball-receiving distributor sleeves or openings 39 will be filled with the tennis balls as the distributor rotates. The distributor 34, when rotated, causes each ball that has been deposited in a sleeve 39, to move into position above a ball feed opening 40 formed in the divider 20. As a result, as each sleeve 39 registers with the divider opening 40, the ball drops through the opening 40. The ball impels a closure or hinged trap door 42 to a temporarily opened position (see FIG. 2). Normally, the trap door is closed by the pressure of air within the chamber 22. The ball drops into a channel-shaped ramp 43 and from there moves into the inlet end of a tubular receiver 44. Receiver 44 at its lower end has an approximately L-shaped rigidly constituted discharge tube 45. The inlet end of tube 45 receives each ball that drops through the opening 40. The tube 45 extends upwardly into communication with a flexible discharge tube 46. This constitutes an extension of tube 45. It extends upwardly within the rear end of the housing above the pressurizing chamber into communication with a barrel means generally designated 47. Barrel means 47 includes a discharge barrel mounting sleeve 48. Any of various barrels or extensions thereof may be connected to the sleeve 48 The discharge barrel mounting sleeve 48 includes at its rear end a pair of transversely spaced, rearwardly projecting, identical but opposite support plates 50. Plates 50 have transversely aligned apertures receiving a connecting pin 52. Pin 52 serves to pivotally mount the barrel mounting sleeve upon a U-shaped support bracket 54. Pin 52 mounts the barrel mounting sleeve 48 for adjustment about a horizontal axis. For example, the sleeve 48 may be adjusted between the full and dotted line positions shown in FIG. 2. In this way the angle at which the balls are discharged can be varied as desired. One may for example desire that the balls be propelled upwardly at a steep angle. This simulates a lob, and the user can practice the return of shots of this type. Or, the barrel can be lowered so as to cause the trajectory of the ball to assume a more nearly horizontal angle. This simulates a low driving return. To adjust the speed at which the ball is discharged, it is preferred to use a velocity control sleeve 55. This has apertures that can be closed, or opened to a selected size. The adjustment is effected by rotation of sleeve 55. One can use any of various barrels. For example a straight barrel 56 can be attached to the sleeve 48. Barrel 56 has a discharge end 57 which as indicated above can be pointed to discharge the ball at any desired angle relative to the horizontal. Or, the sleeve 48 could be adjusted to a fully vertical position as in the dotted line showing of FIG. 2. There can be used in this event an inverted L-shaped barrel 58 curved through 90°. This discharges the balls at a high elevation, simulating serves or deep overhand smashes. It may thus be noted that a discharge conduit generally designated 59 is defined. This begins at the point at which the distributor feeds the balls into the pressurizing chamber. It ends at the discharge end 57. The conduit thus includes the ball feed opening 40, the ramp 43, the rigid discharge tube 45, the flexible discharge tube 46, the discharge barrel mounting sleeve 48, and the barrel 56 or 58. All of the above is conventional. It represents the same basic organization and construction of parts disclosed in U.S. Pat. No. 4,027,646. As in that patent there would be provided of course a temporary ball arresting means (not shown) within the conduit. This momentarily engages each ball, until pressure is built up behind the ball sufficiently to cause it to be forcibly discharged from the barrel. It may be considered that the ball arresting means is incorporated in this disclosure by reference to U.S. Pat. No. 4,027,646. The improvement comprised in the present invention utilizes an upwardly projecting extension shaft 60. This may be detachably connected to the rotor 34 in any suitable fashion in coaxial alignment with shaft 35. For example it may be connected to the upstanding projection 36 of the rotor or distributor 34 by means of a cross pin 59' as shown in FIGS. 2 and 8. A cross brace 61 supports the upper end of extension 60. Referring to FIGS. 3-6, a rotary member, which by way of illustration is depicted as a flat disc 62, is keyed to or otherwise made rotatable with the shaft extension 60. In the illustrated example the distributor 34 and the disc 62 have a one-to-one driving ratio. However, this is not essential. There could if desired be a geared connection between the distributor and the disc. Or some other type of change ratio mechanism could be used to obtain a different driving ratio. For example it may be desired that the disc 62 make two rotational cycles for each single cycle of the distributor. Referring to FIG. 4, a socket 63 on the member 62 receives extension 60. A set screw is threadedly engaged in the side wall of the socket. It bears against extension 60 so that the member 62 and the extension 60 are engaged for joint rotation. This arrangement also permits angular adjustment of the member 62 in respect to the distributor. An adjustment of 30° changes significantly the location at which the tennis balls will be discharged during each oscillating cycle. Referring to FIG. 2, mounted in the housing at the rear end thereof is a gear reduction motor 64. This has a driving pulley 66 about which is trained a drive belt 68. Belt 68 extends about and drives the distributor 34 and hence the disc 62. Referring to FIG. 5, formed in the disc 62 is a radial series of openings or apertures 70a, 70b, 70c, 70d, 70e. All of these openings are spaced at different radial distances from the axis of rotation of the shaft 62. There could obviously be still more openings. This would increase the adjustments possible in use of the invention. For example, there can be openings 70f, 70g, 70h, and 70i of a second series. These occur at radial distances from the center that are staggered in respect to the openings of the first series. All the openings can be numbered 1, 2, 3, etc. This facilitates the following of printed instructions. Instead of a disc there could be secured to the extension shaft 60 a radial or diametrically extending bar 62a (see FIG. 9) having the several openings formed therein. It is mainly important that the rotary member 62 be driven by the shaft 60 simultaneously with rotation of the distributor. Also, it must have one or more openings radially spaced from the axis of rotation. A circular outer shape of the member 62 is not essential to successful use of the device. The improvement comprised in the present invention further includes (see FIGS. 4-6) a drop pin 72. This is removably insertable through an elongated longitudinal slot 74. The slot is formed in the distal end of a flat link 76. The link extends rearwardly from the member 62. At its proximal end it has a progressively widened tongue 78. The tongue terminates in upwardly projecting and transversely aligned, apertured ears 80. The ears are embraced by the sidewalls of the U-shaped bracket 54. Referring to FIGS. 3 and 4, transversely extending connecting pins 82 extend through the respective ears 80. The pins also extend through bearing openings provided in the respective sidewalls of the bracket 54. The openings provide a pivotal connection of the link to the bracket. Thus the link can if necessary swing upwardly and downwardly relative to the bracket or vice versa. It is mainly important to note that when the link is connected to the bracket, the link and support bracket will oscillate as one. They move about a pivot axis defined by a hinge pin 84 extending through a hinge sleeve 86. Sleeve 86 is affixed to the back wall of the U-shaped bracket 54. Pin 84 is mounted upon the housing in any suitable fashion. For example, the lower end of the pin may be welded to a support bracket of inverted L shape 88 secured to the back wall of the housing (see FIG. 4). On each rotation of the disc or equivalent member 62 with the drop pin 72 engaged in a selected one of the openings of the member 62, the link 76 and hence the support bracket will be operated through a single cycle of oscillatory movement. The support bracket will thus be caused to move from one side to the other and back again. In a single oscillation of the bracket the barrel may be caused to move between the left and right hand extreme positions shown in chain dotted outline in FIG. 3. Assume for example that the opening 70a is closest in the radial sense to the axis of rotation of member 62. The width of the oscillatory cycle will be at its narrowest when this opening is used. Conversely the width of the path of oscillation can be progressively increased. This is achieved by using openings of member 62 that are spaced progressively greater radial distances from the axis of rotation of the shaft extension 60. The member 62 or 62a may include a radially extending slot, not shown. In this case the openings 70a, etc., would be provided in the link 76. This would be a pure reversal of parts that would not affect in any way the successful use of the device. It is desirable to keep the back end of the hopper clear. This assures to the maximum extent against interference with the driving mechanism defined by the motor 64 and belt 68. There is provided in the present instance a semi-circular back plate 90. This extends across the rear end portion of the hopper. In back of the plate 90 there is a motor cover plate 92. Formed in the plate 92 is a recess 94 (see FIG. 1) accommodating the tube 46. In use the device is positioned as shown in FIGS. 7a and 7b, in which the distributor is depicted schematically, at one side of a net stretched across a tennis court or other practice area. The barrel is adjusted about its horizontal axis defined by the pin 52. It is set at a selected position of vertical adjustment. Pins 52 may be equipped with thumb screws or equivalent means. These clamp the barrel in selected positions to which it is vertically adjusted. The blower motor and the gear reduction motor 64 are placed in operation. The balls will now be fed in succession through the conduit 59. In the example illustrated each rotation of the distributor 34 will result in propulsion of six balls for each full oscillatory cycle of the barrel. This is shown in FIGS. 7a and 7b. Assume that all of the openings 39 of the distributor are left uncovered. Assume further that the distributor and the disc 62 are connected in a one-to-one driving ratio. The six tennis balls will be propelled at uniformly timed intervals to the locations A, B, C, D, E, and F (corresponding to similarly lettered ball feed sleeves 39 of the distributor as seen schematically in FIGS. 7a and 7b) in a single oscillatory cycle. There is one cycle of oscillation for each 360° cycle of rotation of the distributor. The distributor in the given example has six ball receiving openings 39. One can close off any one or more of the openings 39. This is disclosed in U.S. Pat. No. 4,027,646. If one were to close every other opening 39, only three balls will be propelled in a single cycle of oscillating motion of the barrel. In this event the balls might be propelled to the locations A, C, and E shown in FIGS. 7a and 7b. It is also true that the barrel mounting means can be adjusted vertically. One can thus program the device for propelling balls lob-fashion. Again they would be delivered from side to side of the court. The player may thus practice returning lobs or delivering overhand smashes. In combination with any of these arrangements, one can select any of the various openings of the member 62 or 62a. One may thus narrow or widen the area in which the balls will drop. One can also make the angular adjustment illustrated by the arrows in FIG. 5. This shows an adjustment of member 62 relative to the distributor 34, about their common rotational axis. The angular adjustment shown in FIG. 5 could be any adjustment falling in a wide range of adjustments. Thus, in the disclosed form of the invention, the row of drop-pin-receiving openings 70a-70i of member 62 or 62a can be adjustably disposed anywhere from a location coincident with a particular sleeve 39, to a location in which the row of openings is offset a selected angular distance from said sleeve up to a maximum of 59°. At 60° the row of openings would coincide with the center of the next adjacent sleeve 39 so that it would in effect revert to its initial position. The operational characteristics resulting from the FIG. 5 type of adjustment are illustrated in FIGS. 7a and 7b. In FIG. 7a, assume that the disc opening that receives the drop pin has been angularly offset 60° from the center of the sleeve 39 designated B, which for the sake of this example has been arbitrarily selected as a starting point on the distributor. This locates the pin receiving opening coincident with distributor sleeve A. In FIG. 7b the pin receiving opening has been offset another 30° from said starting point, so that it has now been offset 90° from sleeve B and 30° from sleeve A. Assuming that all other adjustments (for example the barrel elevation, or the selection of a particular one of the openings 70) remain constant, the ball drop pattern produced by oscillation of the barrel is thus seen to differ very materially in the angular adjustment represented by FIG. 7b from that obtained in the adjustment schematically represented in FIG. 7a. In both Figures, the locations at which the balls have been found to drop when the illustrated angular adjustment is used have been indicated by reference letters A, B, etc., corresponding to those of the ball feed sleeves 39. There is thus disclosed a programmed ball discharge adjustable in a comparatively wide range. The user is thus enabled to practice a wide variety of shots. These may be at timed intervals selected according to his or her practice needs. One can indeed swiftly disconnect the oscillating mechanism. This is effected merely by removal of the drop pin 72. In these circumstances, the device would operate without oscillation of the barrel. Also, the manufacturer can make propulsion devices either with or without the oscillating mechanism. This is done with a minimum change of parts. The manufacturer can simply leave off the link 76 and the disc 62. He may also leave off the extension shaft 60. In these circumstances it may be desired to anchor the bracket 54 against side-to-side motion about its pivot pin 84. In this event a set screw, not shown, may be mounted in the sleeve 86. This would be capable of being tightened against the pin 84. This would prevent undesired level deviation of the bracket 54 when the oscillating mechanism is disconnected. Of particular importance is the fact that the distributor and the oscillating mechanism are connected for simultaneous driving from a single source of power. This permits adjustment of the oscillating mechanism to the timed delivery of the balls by the propulsion device. While particular embodiments of this invention have been shown in the drawings and described above, it will be apparent, that many changes may be made in the form, arrangement and positioning of the various elements of the combination. In consideration thereof it should be understood that preferred embodiments of this invention disclosed herein are intended to be illustrative only and not intended to limit the scope of the invention.

A device for propelling tennis balls has an oscillating discharge barrel to which balls are fed from a rotating distributor. A programmed relationship is provided, including a motion-translating linkage oscillating the barrel as an extension of the mechanism used for rotating the distributor. Programming is achieved to cause a predetermined number of objects to be propelled from the barrel, during each oscillatory cycle, as a direct response to rotation of the distributor. The linkage can be optionally provided without changing the basic design of propulsion devices heretofore made. The invention provides this through an extension shaft of the distributor, which rotates a member having openings spaced different radial distances from the axis of rotation of the member. A drop pin is extendable through any of the openings, and through a slot of a motion-translating link connected to a support bracket for the barrel. Vertical adjustment of the barrel, selective adjustment of its angular travel, selective blocking out of distributor feed openings, and a selected drive ratio between the distributor and the motion-translating means combine to effect a wide range of discharge programs. Further variation is achieved by selecting various angular relationships between openings of the motion-translating member, and openings of the distributor.

CROSS REFERENCE TO RELATED APPLICATIONS This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2004-110211 filed on Apr. 2, 2004, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION (1) Field of the Invention The present invention relates to a label and RFID tag issuing apparatus comprising a recording apparatus for recording information on a recording medium and an RFID tag reading/writing apparatus. The invention particularly relates to a production label and RFID tag issuing apparatus that issues a production label and an RFID tag, comprising a recording apparatus that records information on a recording medium to be affixed to a container used in factory automation (FA) process or other applications and an RFID tag reading/writing apparatus that can write to the RFID tag coupled with the recording medium part of the information recorded on the recording medium. (2) Description of Related Art Today, to manage articles, a bar-code and RFID tag are used in combination. Japanese patent application Kokai publication No. 2001-229344 describes a data processing apparatus that can convert data between bar-code data and RFID tag data and manage articles using the converted data. This data processing apparatus comprises an RFID tag reader/writer, a data converting means for converting data between bar-code data and RFID tag data, a bar-code reader, and a bar-code printer. The apparatus operates such that the data converting means converts bar-code data decoded from a bar-code that is read by a bar-code reader into RFID tag data, which is then written to an RFID tag, while the data converting means converts RFID tag data read from an RFID tag by the RFID tag reader/writer into bar-code data, which is then inputted to a printer and recorded. Thereby, for example, data of a bar-code recorded on a contained article can be registered in an RFID tag of a carried container, and data related to an article can be efficiently managed. In a FA process, for example, a production article or articles such as personal ornaments contained in a container move between a plurality of work flow stages, at each of which an operator does his/her prescribed work picking up the articles from the container and puts them back to the container after finishing the work. In order to manage the traveling container and production articles therein, an RFID tag storing managing data and a production label recording the managing data are attached to one container so that the managing data can be electronically managed by using the RFID tag and the operator can visually confirm the production article by the production label. In such a case, the managing data recorded in the production label on the container must correspond to the managing data stored in the RFID tag that is attached to the same container. However, the data processing apparatus described in Japanese patent application Kokai publication No. 2001-229344 is not structured such that a production label and an RFID tag are affixed to the same container wherein issuing of the production label containing managing data to be affixed to the container is related to issuing of an RFID tag containing managing data to be attached to the container. Therefore, a problem arises that an operator accidentally affixes a production label to a wrong container to which an RFID tag that does not correspond to the production label is attached. SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for issuing a recording medium and an RFID tag coupled with the recording medium, maintaining a tight relation between the recording medium such as production label that records information and the RFID tag to which part of the information of the recording label is written. Another object of the invention is to provide a recording medium and RFID tag issuing apparatus, which comprises a detecting means for detecting presence of a container containing manufacturing articles to which an RFID tag has been previously provided or is to be attached later, a printer for recording information on a recording medium to be affixed to the container, an RFID tag writing means for writing to the RFID tag part of information recorded on the recording medium, and a control means for authorizing the printer to record the information on the recording medium when the detecting means has detected the presence of the container after the writing means has written the part of the information to the RFID tag. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a functional structure pertaining to the first embodiment. FIG. 2 is a diagram illustrating a container used in the first embodiment. FIG. 3 is a flow chart illustrating a process of label and RFID tag issuing controlled by the control section in the first embodiment. FIG. 4 is a block diagram of a functional structure pertaining to the second embodiment. FIG. 5 is a flow chart illustrating a process of label and RFID tag issuing controlled by the control section in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. The same numerals are applied to the similar elements in the drawings, and therefore, the detailed descriptions thereof are not repeated. First Embodiment As shown in FIG. 1 , the label and RFID tag issuing apparatus according to the first embodiment consists of a control section 1 , a weight sensor 2 connected to the control section 1 , an RFID tag reader/writer 3 , a printer 4 , a display 5 , an input section 6 , and a bar-code reader 7 . The weight sensor 2 detects the container 1 loaded on a container loading plate 9 . The bar-code reader 7 is of a handy type that is convenient to handle in a production process. The control section 1 is a control means consisting of a microprocessor and memory and others, and controls outputting recording data to the printer 4 according to programs, outputting information to be displayed to the display 5 , inputting input data from the input section 6 , inputting bar-code data from the bar-code reader 7 . The printer 4 may be any of a thermal printer, ink jet printer, wire-dot printer, etc. When this label and RFID tag issuing apparatus is used on a process of manufacturing articles, for example, personal ornaments, the weight sensor 2 is installed in the container loading plate 9 for loading a container 8 containing the manufacturing articles, and detects the container 8 loaded on this container loading plate 9 . The control section 1 detects presence of the container by inputting output from the weight sensor 2 and judging if a magnitude of the output conforms to the weight of the container 8 . As shown in FIG. 2 , the container 8 is provided with a pocket on a surface of the container at its lower part for containing and holding the RFID tag 10 , and the upper part of the container on the surface is designed so that the recording paper 12 , which is to become a production label, can be affixed thereto. The production label herein refers to a printed material on which information needed for manufacturing a product such as production number, product name, process instructions instructing works to be carried out in individual stages of the process is recorded. It is so structured that the RFID tag 10 can be contained in and taken out of a container pocket 11 . The container 8 , which contains trinkets such as personal ornaments, forms a box having a lid so as to prevent the articles contained therein from being scattered. The form of the container may be designed according to the size of an article or articles to be manufactured. The control section 1 is configured so as to output to the RFID tag reader/writer 3 data to be written to the RFID tag 10 and input data that the RFID tag reader/writer 3 has read from the RFID tag 10 . The RFID tag reader/writer 3 is connected to an antenna 13 disposed in the vicinity of the container loading plate 9 . The RFID tag reader/writer 3 radiates an electromagnetic wave through the antenna to the container carrying the RFID tag 10 on the container loading plate 9 . The RFID tag 10 generates a power from the electromagnetic wave received, writes and reads data to/from the RFID tag 10 , and transmits the data to the RFID tag reader/writer 3 . The printer 4 records production information including a bar-code, that is, data pertaining to production on the recording paper 12 . The display 5 displays information for indicating to an operator. The input section 6 inputs data to record on the recording paper 12 and data to be written to the RFID tag 10 . The bar-code reader 7 is used to read a bar-code 12 a on the recording paper 12 when a bar-code is recorded thereon. FIG. 3 is a flow chart illustrating operation of the label and RFID tag issuing apparatus according to this embodiment. In step S 1 , information to be written and recorded onto the RFID tag and recording paper is inputted from the input section. In step S 2 , it is judged whether or not the container 8 is on the container loading plate 9 by taking the output from the weight sensor 2 . If presence of the container 8 is detected, in step S 3 , the control section 1 controls the RFID tag reader/writer 3 so that the RFID tag reader/writer 3 writes part of production information to be recorded by the printer 4 , for example, a production number, into the RFID tag 10 attached to the container 8 . When the writing is done, in step S 4 , the RFID tag reader/writer 3 reads the production number that has been written just now. In step S 5 , the read production number is now compared to one written to examine if the production number has been correctly written to the RFID tag 10 . If a judge is made that it is not correctly written, the writing is reiterated. If a judge is made that it is written correctly, in step S 6 , presence of the container 8 on the container loading plate 9 is then checked. If presence of the container 8 is confirmed, in step S 7 , the control section 1 controls the printer 4 so that the printer 4 records on the recording paper 12 information pertaining to production including a bar-code that corresponds to the production number written to the RFID tag. Then, an operator adheres this recording paper 12 on the container 8 to which the RFID tag 10 is attached. After this recoding has been done, in step S 8 , the process control keeps monitoring whether or not the container is removed from the container loading plate 9 while observing the weight of the container on the loading plate. If the removal of the container 8 is acknowledged, then in step S 9 , the apparatus waits entry of “termination of the issue process” from the input section 6 . In step S 9 , if input of the termination is not received, then, the process control waits in step S 1 entry from the input section 6 of information to be issued in a subsequent process. If the termination of the issue process is received, the current control of the issue process terminates. In this embodiment, when an operator inputs information to be issued, wherein the container 8 holding the RFID tag 10 in the pocket 11 in which no data has been written is placed on the container loading plate 9 , the control section 1 first confirms the presence of the container 8 on the container loading plate 9 by the output from the weight sensor 2 and writes a production number into the RFID tag 10 controlling the RFID tag reader/writer 3 . The production number just written is read back to the apparatus to check if the number has been written correctly. If the correct writing is verified, presence of the container 8 on the container loading plate 9 is rechecked, and production information including a bar-code that corresponds to the production number written to the RFID tag 10 is recorded onto recording paper 12 by the printer 4 . In this manner, the apparatus can write a production number to the RFID tag 10 in a state that the container 8 is placed on the container loading plate 9 , and issue recording paper 12 on which production information including a bar-code corresponding to one written to the RFID tag 10 has been recorded, assuring that the container 8 is still on the container loading plate 9 . That is, when the recording paper 12 recording production information including a bar-code corresponding to one written to the RFID tag 10 is issued, the container 8 carrying the corresponding RFID tag 10 surely exists on the container loading plate 9 . The operator needs only to take the container 8 on the container loading plate 9 and affix the recording paper 12 just issued on the container 8 . By this action, the recording paper 12 which records production information including bar-code 12 a corresponding to one written to the RFID tag 10 can be surely affixed on the container 8 , as shown in FIG. 2 . Because removal of the container from the container loading plate 9 by the operator automatically leads to a stage that the apparatus waits a subsequent issue process, the subsequent issue process cannot commence in a state that the previous container is being left on the container loading plate 9 . Accordingly, there would be no fear that a recording paper 12 recording production information that does not correspond to a production number written in the RFID tag 10 attached to one container 8 could be affixed to the same container 8 . Second Embodiment FIG. 4 shows a label and RFID tag issuing apparatus using an optical sensor 14 as a detecting means. The structure of this embodiment excluding the optical sensor 14 is the same as one of the fist embodiment. For the optical sensor, a reflective type that incorporates a combination of a light emitting element and photo acceptance element is used. This optical sensor detects presence of the container 8 on the container loading plate 9 , when the container 8 is placed on the container loading plate 9 , by the output of the photo acceptance element, which receives light that is emitted from the light-emitting element and then reflected on the container 8 . In this way, the same effect can be attained using an optical sensor as the detecting means. Although the above descriptions were made for structures using the weight sensor and optical sensor, this invention is not limited to such practices. It is possible to make the RFID tag reader/writer 3 serve as double functional apparatus, eliminating use of such sensors. Specifically, first, the RFID tag 10 storing dummy data is prepared beforehand, and the RFID tag reader/writer 3 is provided to operate constantly. In this state, when the container 8 is placed on the container loading plate 9 , the RFID tag reader/writer 3 detects the presence of the container 8 on the container loading plate 9 by reading the dummy data from the RFID tag 10 . After a real production number has been written to the RFID tag 10 , the presence of the container 8 on the container loading plate 9 can be detected by reading the production number. By making the RFID tag reader/writer 3 serve also as a detecting means in this manner, the apparatus structure can be simplified. Third Embodiment A structure of the label and RFID tag issuing apparatus according to the third embodiment is shown in FIG. 1 . The container 8 used therein carries the recording paper 12 recording a bar-code and the RFID tag 10 , as illustrated in FIG. 2 . The controller 1 performs the issue process according to the procedure described in FIG. 5 . That is, after information to be issued is taken in from the input section 6 in step S 11 , presence of the container 8 on the container loading plate 9 is judged by the output from the weight sensor in step 12 . After the presence of the container 8 is confirmed, in step 13 , the controller 1 makes the printer 4 print on the recording paper 12 production information including a bar-code corresponding to a production number. First, a recording paper 12 is issued, and then, in step 14 , the bar-code reader 7 reads the bar-code 12 a recorded on the issued recording paper 12 . In this instance, the controller 1 makes a display device indicate an instruction urging an operator to read and confirm the recorded bar-code, and the operator operates the bar-code reader 7 to read the recorded bar-code according to the instruction. In step 15 , the bar-code that has been read is compared with the bar-code data that has been recorded on the recording paper in step 13 to judge if the data of the bar-code has been correctly recorded. When correctness of the recording is verified, in step S 16 , presence of the container 8 on the container loading plate 9 is checked. If the presence of the container 8 is confirmed, in step S 17 , the controller 1 makes the RFID tag reader/writer 3 write to RFID tag 10 data corresponding the bar-code, for example, a production number, which is part of information pertaining to production recorded on the recording paper 12 . With this writing done, in step S 18 , the RFID tag reader/writer 3 reads the production number that has just been written. In step S 19 , the production number that has been read is compared with one that was originally written so that check is made to see if the production number was correctly written to RFID tag 10 . If a failure of correct writing is judged, writing to the RFID tag 10 is reiterated. If correct writing is verified, in step S 20 , the process control watches if the container 8 is removed from the container loading plate 9 and judges so if it has been done. When the removal of the container 8 is confirmed, in step S 21 , the process control watches if “termination of the issue process” is received from the input section 6 and judges so if it has been done. Unless it is received, the process control waits entry of information to be issued for a subsequent issue process from the input section 6 . If “termination of the issue process” is confirmed, the current issue process terminates. In this structure of the embodiment, first, production information including a bar-code data corresponding to a production number is recorded on a recording paper 12 in a state that the container 8 is placed on the container loading plate 9 . Then, the production number is written to the RFID tag 10 in a state that the container 8 is placed on the container loading plate 9 . Because the container 8 to which the recording paper 12 is affixed remains on the container loading plate 9 until the production number is written on it, the operator only needs to withdraw the container 8 on the container loading plate 9 and affix the recorded paper 12 to the container at the point when the writing of the production number has been completed. In this case also, the recording paper 12 recording the production information including a bar-code corresponding to the production number written to the RFID tag 10 can be certainly affixed to the container 8 . In this embodiment also, an optical sensor can be used as a detecting means instead of the weight sensor. Alternatively, the RFID tag reader/writer may be used as a dual-purpose apparatus having a function of the detecting means by writing dummy data in the RFID tag 10 . In the above embodiments, descriptions have been made for structures in which presence of the container carrying an RFID tag is detected by a detecting means. This invention is not limited to such structures. There may be such a structure in which the container and RFID tag are separated and only RFID tag is detected by a detecting means. Even in this case, since the RFID tag can be related to a recording paper, the two media would need to be attached to a common container. Although the above descriptions have been made as examples using a production label like one used in automated factory processes, the invention is not limited to those practices. This label and RFID tag issuing apparatus can be adapted in applications of stock control and physical distribution management, wherein a label that records data related to data having been written to an RFID tag is affixed to a container. Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the present invention can be practiced in a manner other than as specifically described therein.

A label and RFID tag issuing apparatus comprises a recording apparatus that records information on a production label and an RFID tag reader/writer that writes and reads part of the recorded information to/from an RFID tag. This label and RFID tag issuing apparatus writes a production number to the RFID tag attached to the container if a container for containing an article or articles carrying the production label and RFID tag is judged to be on the container loading plate. The apparatus, subsequently confirming presence of the container on the container loading plate, records on the production label production information including bar-code data corresponding to the production number that has been written to the RFID. Thus, information recorded on the production label and information stored in the RFID tag are tied, and thereby accidental affixing of a wrong production label onto the container can be prevented.

TECHNICAL FIELD [0001] The present invention relates to reducing oil carry-over in internal combustion engines. In particular, but not exclusively, the invention relates to a barrier device provided in the cylinder block of an internal combustion engine to reduce the amount of oil being carried over from the crankcase to the crankcase breather system. BACKGROUND [0002] Internal combustion engines suffer from a process called blow-by where combustion gasses leak past the piston rings into the crankcase. To prevent seal damage these gasses will have to be vented, which can be done by a closed circuit breather system (CCB) or an open circuit breather system (OCB). When using an OCB, the gasses flow from the crankcase to the cylinder head and are from there vented to atmosphere. With a CCB, the gasses flow from the crankcase to the cylinder head and are from there re-introduced into the induction system, where they are burned off and subsequently depart the engine via the conventional exhaust system. [0003] A major problem associated with both OCB and CCB systems is that the blow-by gasses usually carry a substantial amount of oil particles caused by reciprocating and rotating elements in the engine. This process is called oil carry-over and can pose several problems: in certain CCB systems the vented gas is fed through a filter to minimise the amount of carry-over oil in the blow-by gasses, before introduction of the gasses into the intake manifold for combustion. As the filter is an expensive service item, oil carry-over increases operating costs; in CCB systems without a filter, the oil can cause fouling of components of the induction system such as turbocharger compressor vanes and engine poppet valves. Also, the liquid oil can form deposits on the valves which can be detrimental to the performance of the air intake system; in OCB systems where the gasses are vented to air, oil carry-over can raise emission levels significantly; oil carry-over can be a significant cause of oil loss and hence increases operating costs. [0008] It is known to provide a PCV (Positive Crankcase Ventilation) valve to limit oil carry over. An example of such an apparatus is disclosed in U.S. Pat. No. 5,024,203. However, this design has several undesired characteristics in that it is fitted external to the engine thus enlarging the engine envelope, it requires a controlled heating process of the vapours, and several additional flow paths must be added to the engine to control the flow of the fluids involved. This combination of factors make the design complex, expensive, and introduces significant design constraints for both the engine manufacturer and the customers who wish to incorporate the engine into their products. [0009] The present invention is directed to solving one or more of the problems set forth above. SUMMARY OF THE INVENTION [0010] According to a first aspect of the present invention, there is provided an internal combustion engine with a cylinder block defining a first chamber, a second chamber and a passage connecting the first chamber and the second chamber. The passage allows gas flow between the first chamber and the second chamber. The internal combustion engine further has a barrier device positioned in the cylinder block with an impact surface located in the gas flow adjacent to a downstream end of the passage. The passage has a cross-sectional area and shape such that said gas flow has a velocity causing oil particles in the gas flow to impact on the impact surface. The impact surface extends over the cross-sectional area of the passage and substantially impedes oil particles in the gas flow whilst allowing gas to flow past the impact surface. [0011] According to a second aspect of the present invention, an internal combustion engine has a first engine component with a passage therein, a second engine component and gasket sealing between the first and the second engine components The gasket has at least one perforation to allow gas flow from the passage in the first engine component to the second engine component. The gasket includes a barrier device positioned in the gas flow adjacent to a downstream end of the passage. The passage has a cross-sectional area and shape such that the gas flow has a velocity causing oil particles in the gas flow to impact on the impact surface. The impact surface extends over the cross-sectional area of the passage and substantially impedes oil particles in the gas flow whilst allowing gas to flow past the impact surface. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a cross-sectional view of an internal combustion engine indicating the flow path of the gasses that are to be vented from the crankcase. [0013] FIG. 2 is a fragmentary cross-sectional view of a portion of an internal combustion engine illustrating a first embodiment of the present invention. [0014] FIG. 3 is a perspective view of a barrier device as illustrated in FIG. 2 . [0015] FIG. 4 is a fragmentary cross-sectional view of a portion of an internal combustion engine illustrating a second embodiment of the present invention. [0016] FIG. 5 is a plan view of a barrier device as illustrated in FIG. 2 . [0017] FIG. 6 . is a fragmentary cross sectional view of a portion of an internal combustion engine illustrating a third embodiment of the present invention. [0018] FIG. 7 is a fragmentary cross-sectional view taken along line 7 - 7 of FIG. 6 . [0019] FIG. 8 is a fragmentary cross-sectional view similar to FIG. 7 , but showing an alternative arrangement. [0020] FIG. 9 is a fragmentary cross sectional view of a portion of an internal combustion engine illustrating a fourth embodiment of the present invention. [0021] FIG. 10 is a fragmentary, top plan view looking in the direction of arrows 10 - 10 of FIG. 9 . DETAILED DESCRIPTION [0022] For clarity the following description refers to a single cylinder engine only, but the principle can of course as easily be applied to multiple cylinder engines. [0023] With reference to FIG. 1 . an internal combustion engine 10 according to this invention has a first chamber such as a tappet or camshaft chamber 12 , a second chamber such as a vent chamber 14 and a passage 16 connecting the two chambers. Engine 10 further comprises a cylinder head 18 , a cylinder block 20 , a gasket 22 positioned between cylinder block 20 and cylinder head 18 and a crankcase 24 . Blow-by gasses to be vented from crankcase 24 flow from crankcase 24 through respectively tappet chamber 12 , passage 16 , vent chamber 14 , and gasket 22 to cylinder head 18 . The oil particles carried by the gasses are mainly introduced before the gasses enter passage 16 . [0024] Four embodiments of this invention are described below in detail. Generally, each embodiment comprises an impact surface which is positioned adjacent to the downstream side of a passage connecting a first chamber and a second chamber. The impact surface extends over the passage in such a manner that substantially all gas flow is directed onto this impact surface. The passage has a both pre-determined cross-sectional area and shape such that the gas flow through the passage maintains or obtains a velocity within a pre-determined velocity range so it causes the oil particles carried by the gas flow to impact on the impact surface preferably with minimal atomisation of the particles on impact. The gas flow can continue, but the inertial impact of the oil particles on the impact surface cause the oil particles to coagulate and form oil droplets. As the droplets reach a certain size they depart from the impact surface and the droplets return to the first chamber. [0025] FIGS. 2 and 3 illustrate a first embodiment of this invention. A barrier device, generally designated 26 , is positioned adjacent to passage 16 in cylinder block 20 . Barrier device 26 is preferably made from a plastic material, but other suitable materials such as metals or composites can also be used. Barrier device 26 comprises impact member 28 having impact surface 30 and at least one but preferably two or more supporting members 31 having lower abutments 34 and upper abutments 36 . Supporting members 31 in combination with abutments 34 and 36 secure barrier device 26 by means of a snap-fit in passage 16 . [0026] Barrier device 26 is fitted in chamber 14 via aperture 32 . After fitting barrier device 26 and carrying out any other desired operations, aperture 32 is closed off by for example press-fitting or threading plug 33 into aperture 32 . [0027] The gas flow carrying the oil particles travels at a velocity within a desired velocity range after leaving passage 16 . The gas flow continues by flowing through apertures 35 between supporting members 31 . The inertia of the oil particles causes the oil particles to impact on impact surface 30 , and thus the oil particles coagulate to form oil droplets. As the droplets reach a certain size they depart from impact surface 30 and the droplets either fall back through passage 16 or run back via supporting members 31 into tappet chamber 12 . [0028] FIGS. 4 and 5 show a second embodiment of the present invention, wherein a barrier device, generally designated 126 , is fitted adjacent to the downstream side of passage 116 in cylinder block 120 . Barrier device 126 is preferably made from a plastic material, but other suitable materials such as metals or composites can also be used. Barrier device 126 comprises a body 137 having a generally rectangular shape, but the body 137 could have any other suitable shape. Body 137 comprises a plurality of locating portions such as tabs 138 , an impact member 128 having impact surface 130 , cross-members 139 , and one or more perforations 140 . [0029] Barrier device 126 is fitted in chamber 114 via aperture 132 . After fitting barrier device 118 and carrying out any other desired operations, aperture 132 is closed off by for example press-fitting or threading plug 133 into aperture 132 . [0030] Barrier device 126 is secured by engaging locating portions 138 in receiving portions such as recesses (not shown) formed by the walls that define chamber 114 . [0031] The gas flow carrying the oil particles travels at a velocity within a desired velocity range after leaving passage 116 . The gas flow continues by flowing through perforations 140 . The inertia of the oil particles causes the oil particles to impact on impact surface 130 , and thus the oil particles coagulate to form oil droplets. As the droplets reach a certain size they depart from impact surface 130 and the droplets fall back through passage 116 . [0032] FIGS. 6, 7 , and 8 illustrate a third embodiment of the present invention, wherein a barrier device 226 projects from an inner wall surface 227 of cylinder block 220 adjacent to the downstream side of passage 116 . Impact member 226 is preferably made from metal, but other suitable materials such as plastics or composites can also be used. Barrier device 226 can be an integral cast part of cylinder block 220 or, alternatively it can be fitted after block 220 has been cast by methods well known to those skilled in the art, such as a press-fit or by using an adhesive. [0033] If barrier device 226 is fitted after casting of cylinder block 220 , barrier device 226 is fitted in chamber 214 via aperture 132 . After fitting barrier device 226 and carrying out any other desired operations, aperture 232 is closed off by for example press-fitting or threading plug 233 into aperture 232 . [0034] The gas flow carrying the oil particles travels at a velocity within a desired velocity range after leaving passage 216 . The gas flow continues by flowing around impact member 226 . The inertia of the oil particles causes the oil particles to impact on impact surface 230 , and thus the oil particles coagulate to form oil droplets. As the droplets reach a certain size they depart from impact surface 230 and the droplets fall back through passage 216 . [0035] An alternative shaped barrier device is shown in FIG. 8 wherein impact surface 230 is arcuate as opposed to the generally flat surface as shown in FIGS. 6 and 7 . [0036] In FIGS. 9 and 10 an internal combustion engine 310 comprises a cylinder block 320 , a cylinder head (not shown) and a gasket 322 disposed between cylinder block 320 and the cylinder head. Gasket 322 , which can be conventional except as described herein, comprises a body 350 , at least one barrier device or impact portion 326 projecting from body 350 having impact surface 330 , and at least one perforation 356 . Gasket 322 can be considered part of cylinder block 320 for the purpose of this invention. Cylinder block 320 comprises vent chamber 314 having throat area 358 , passage 316 and tappet chamber 312 . [0037] The embodiment shown in FIGS. 9 and 10 uses the same general principle as described with regards to FIGS. 2 to 8 with the main difference being the impact member has been repositioned. [0038] Impact portion 326 is positioned in such a manner that the gas flow carrying the oil particles leaving throat area 358 of chamber 314 are obstructed by impact portion 326 . Throat area 358 has a both pre-determined cross-sectional area and shape such that the gas flow through the throat area maintains or obtains a velocity within a pre-determined velocity range so it causes the oil particles carried by the gas flow to impact on the impact surface 330 preferably with minimal atomisation of the particles on impact. Therefore throat area 358 functions similarly to passages 16 , 116 and 216 as described above. Consequently, throat area 358 can be considered a passage for purposes of this invention. [0039] The gas flow carrying the oil particles travels at a velocity within a desired velocity range after leaving throat area 358 . The gas flow continues by flowing around impact portion 326 . The inertia of the oil particles causes them to impact on impact surface 330 , and thus the oil particles coagulate to form oil droplets. As the droplets reach a certain size they depart from impact surface 330 and the droplets fall and run back through vent chamber 314 into passage 316 and then into tappet chamber 312 . INDUSTRIAL APPLICABILITY [0040] In use, this invention provides a simple and robust solution to reduce the amount of liquid oil particles carried over to a crankcase ventilation oil filter or to the induction system of an engine. Gas flow from the crankcase 24 passes through a passage 16 , 116 , 216 , 358 formed in the cylinder block 20 , 120 , 220 , 320 . This ensures that oil particles carried by the gas flow have sufficient inertia that they impact against an impact surface 30 , 130 , 230 , 330 positioned adjacent to the downstream end of the passage. However, the gas flow may continue past the impact surface 30 , 130 , 230 , 330 . As a result, oil particles are removed from the gas flow, and the oil particles can coagulate to form droplets that then return to the crankcase and engine sump. [0041] This invention can be readily fitted to existing engine designs without requiring substantial modification to the engine design. Moreover, because the invention is generally contained within the engine, the benefits of the invention can be obtained without increasing the space claim of the engine. In some cases, this invention may also be fitting to existing engines. [0042] This invention is particularly useful in engine application that are likely to generate high levels of oil particles carried by the crankcase gases. One example of such an application is an engine for a hydraulic excavator. In a hydraulic excavator, the repeated slewing of the excavator during digging operations can cause increased splashing of oil within the engine, thereby increasing the likelihood that small oil particles will travel with the gas flow. For applications that present particularly high levels of oil particles in the gas flow, those skilled in the art will recognize that one of more of the embodiments of FIGS. 2-8 can be combined with the embodiment of FIGS. 9-10 to further reduce oil carry over. [0043] Although the preferred embodiments of this invention have been described, improvements and modifications may be incorporated without departing from the scope of the following claims.

To prevent seal failure in internal combustion engines, blow-by gasses leaking past the piston rings require venting. However, moving engine components cause airborne oil particles to be mixed in with the gasses. Depending on breather system and engine type, oil carry-over can cause increased operating costs, reduced engine performance and emissions issues. The present invention provides a simple and inexpensive barrier device fitted in a cylinder block. The device is positioned such that oil particles impact on the device and coagulate to form droplets which subsequently run back to the crankcase. Some advantages provided by the present invention are that the engine envelope is unaffected, the barrier device is the only additional part, and the cylinder block requires no or minimal adaptation.

The present invention refers to a device for folding at least one edge of a fabric for making a single or double hem, said fabric edge being passed through shaping means contained in the device. BACKGROUND OF THE INVENTION Hem shaping means are known in a plurality of different embodiments. The most common means consists of a helical, conical sleeve through which the fabric edge is passed at the same time as the folding takes place. There is also previously known a hem shaping means consisting of two folding bars provided with upwards directed portions between which and the bars the folding takes place. Fixed bars, however, involves, that the once chosen space between the bars for a safe-folding and transport of the fabric edge through the folding device cannot be instantaneously changed in order to let a transverse seam with a considerably larger thickness than the actual fabric edge pass. This means that fabrics with transverse hems cannot or only with difficulty be sewn in such hem-shaping means, which is an obvious drawback. SUMMARY OF THE INVENTION The object of the present invention is to provide a folding means, which within a relatively large area with respect to the most common fabrics, is insensitive for variations of the thickness of the fabric, whether more than one fabric edge is to be folded simultaneously or if transverse seams with a considerable thickness occur. This object has been solved by the fact, that the shaping means comprises portions of at least one endless, driven band, which is twisted in correspondance with the gradual folding of the fabric edge during the transport thereof through the device and said band being arranged to cooperate with at least one fixed rule arranged in direct connection with at least a part of the band portions. DESCRIPTION OF THE DRAWINGS FIG. 1 shows the folding device according to the invention in a view from above. FIG. 2 shows the folding device according to FIG. 1 in a side view. FIG. 3 shows in perspective endless bands and rules contained in the folding device. FIGS. 4-9 are sections according to the lines IV--IV, V--V, VI--VI, VII--VII, VIII--VIII och IX--IX respectively in FIGS. 1 and 2. FIG. 10 shows in side view and in section a modified embodiment of the folding device according to the invention. FIG. 11 shows the folding device according to FIG. 10 in a view from above. FIG. 12 shows the folding device according to FIGS. 10 and 11 in perspective. FIG. 13 shows a portion of the feed table 11 seen from inside the folding device. FIGS. 14-19 are sections according to the lines XIV--XIV, XV--XV, XVI--XVI, XVII--XVII, XVIII--XVIII and XIX--XIX in FIG. 11. FIG. 20 shows the central portion of the feed table in a view from above. DESCRIPTION OF EMBODIMENTS The folding device according to the invention consists of a feed table 11 on the table top 12 of which the fabric 13, which is to be provided with a fold is transported. The transport takes place by means of an endless band 14 (only one band part is shown), which feeds the fabric in the longitudinal direction of the table. At one side edge of a table a vertical rail making one first folding rule of the folding device is arranged. Outside the rule 15 there is arranged a first endless transport band 16, along which a first shaping section 17 is arranged essentially vertically and substantially parallel to and in contact with the rule 15. A number of guide rollers 18-21 and a pulley roll keep the band part in question in position. The endless band 16 is by way of the pulley rolls 23, 24, the drive roll 25, the stretching roll 26 and the pulley rolls 27 and 28 driven in the direction of the arrow 29. A second endless band 30 is arranged opposite the rule 15 and cooperating with this, said band at the beginning of the first shaping section 17 has a substantial horizontal position and is gradually towards the pulley roll 22 twisted to vertical position. The band 30 extends from the pulley roll 22 further to the pulley rolls 31 and 32, to the drive roll 33 and by way of a stretching roll 34 to the pulley roll 35, and returns after that to the pulley roll 22. The twisting of the second band part 30 from horizontal position at the guide roll 18 to vertical position at the pulley roll 22 is supported and guided by support rolls 36 and 37. The first band 16 continues from the press nip between the rolls 21 and 22 from vertical position to horizontal position at the pulley roll 24, and during this twisting movement, i.e. a second shaping section 38, the band part in question will be brought to contact against a second rule 39. This is also twisted in the corresponding way as the band section in question and this rule is in the same way as the rule 15 fixed to the table top 12. All the rolls supporting and driving the two endless bands are mounted in a frame 40. The folding device according to the invention functions in the following way. The two bands 16 and 30, which are driven by a common motor (not shown) are displaced in the direction of the arrow 29, i.e. at the shaping sections 17 and 38 in the same direction as the transport band 14. A fabric 13 which is clamped between the band part 14 and the table 12 will thus be displaced along the entire folding device. The fabric 13 is then guided into the folding device, so that the edge 13a will hang over the table edge 12, as is shown in FIG. 4. The overhang 13a is guided in between the rule 15 and the first band part 16. The projecting end portion of the fabric edge will by that come to contact with the second band part 30, which at the entrance of the fabric edge in the folding device takes a substantial horizontal position. Concurrently with the displacement of the fabric edge through the folding device the end portion 13a will be folded up more and more against the inside of the rule 15. By means of the second band part 30, which is twisted from horizontal position to vertical position. The vertical position of the first band part 16 helps to transport the fabric edge on the outer side of the rule 15. At the section VII--VII in FIGS. 1 and 2 the fabric edge has been folded in U-shaped about the rule 15 and the two shanks of the U are fixed by the bend part 16 and 30 each. At the section VIII--VIII the fabric edge has left its engagement with the band part 30 and the end portion 13a of the fabric edge has been brought into contact with a second rule 39 of the folding device extending from the pulley roll 22 vertically to horizontal position at the pulley roll 24. The fabric edge will in cooperation with the first band part 16 be gradually folded in the second shaping 38 in the direction towards the table top 12, so that when the fabric edge leaves the pulley roll 24 a double folded hem has been provided. In direct connection to the pulley roll 24 there is arranged a connection approach 41 to a sewing machine, where the hem is sewn. In order to permit also very thick material portions in the form of transverse seams get past the guide rolls 18, 19, 20 and 21. These are spring-loaded and can thus spring aside if the material thickness suddenly is increased. The embodiment according to the FIGS. 10-19 differs from the previous embodiments by the fact that the shaping means comprises one single endless, driven band 50 cooperating with a shaping rule 51, which is fixed to the feed table 11. The endless band 50 is driven by a drive roll 52 by a motor (not shown). The band 50 extends from the drive roll 52 by way of three pulley rolls 53, 54 and 55 to a position in which a band is located on a level with the table top 12 of the feed table 11. The band portion 50a between the roll 55 and the roll pair 56 is twisted 180° so that the band portion during a substantial part of its length will be in contact with the correspondingly shaped shaping rule 51. The roll pair 56 consists of the rolls 57 and 58, of which the first mentioned roll 57 is stationary and the second roll 58 is pivotable about axle 59 of the first roll 57. A spring 60 which gives the roll 58 a contact pressure against the table top 12 is also arranged at said axle 59. From the roll pair 56 the band continues with a 180° twisting to the roll 61 located on a somewhat lower level as compared to the roll 55. The band part 50b follows during a portion of its length the twisting of the band part 50a. The band 50 continues from the roll 61 to the pulley rolls 62 and 63 and then further as a band part 50c in 180° twisting to a second roll pair 64, which in the same way as the first roll pair 56 consists of a stationary roll 65 and a roll 66 which with respect to this is pivotable and spring-loaded. This roll 66 presses a portion of the band part 50d to contact against the table top 12. The band part 50d continues from the undersides of the roll pair 64 with 180° twisting to the pulley roll 67 and then back to the drive roll 52. The feed table 11 is as previously mentioned provided with a shaping rule 51 consisting of a plate strip, which at one end 68 of the feed table is located flash and on the underside of the tabletop 12. The roll is twisted 180° and its opposite end portion 69 connects tangentially on to the pulley roll 63, which projects into a recess 70 in the table top 12. In order to provide a sufficient track tension one of the pulley rolls, e.g. the roll 61 is displaceably arranged in a groove 71 along which the pulley roll is attachable. In the feeding direction of the fabric as seen from the front of the folding device there is arranged an infeed table 72 with stop edge 73, which is located at the distance a (FIG. 11) from the rear side edge of the table top 12, which distance a is a measure of the length of the future double hem. By changing the measure a, for example by displacing the folding device somewhat sidewards, the width of the hem is also changed. The device functions in the following way: A piece of fabric 13, e.g. a sheet, which by appropriate transport means as endless transport bands, not shown, is transported along the feed table 72 with the fabric edge which is to be hemmed, contacting the side edge 73 of the feed table, will be inserted under the roll 66 of the first roll pair 64 and gets its continued transport movement by the endless band 50 of the folding device in cooperation with the table top 12 and the shaping rule 51 respectively. When the piece of fabric has reached the section line XIV--XIV in FIG. 11 the piece of fabric 13 is by the band portion 50d pressed against the table top 12, while the projecting portion 13a of the piece of fabric 13 corresponding to the measure a will hang freely downwards along the free longitudinal side edge of the table top, as is shown in FIG. 14. During the continued displacement along the feed table 11, 12 on to the section line XVI--XVI the projecting fabric edge 13a will by the 180° twisted band part 50d be turned to contact the underside of the table top 12. Just opposite the roll 63 in the table top 17 there is provided a recess 70 permitting the fabric edge 13a located on the underside of the table top to leave the table top as is shown in FIG. 16. The continued displacement of the piece of fabric through the folding device is now taken over by the band part 50a, which transports the folded fabric edge along the shaping rule 51. Since the band part 50a from the roll pair 56 to the roll 55 is twisted 180° in the same way as the shaping rule 51, the ones folded fabric edge 13a will be exerted to a further folding, so that a double folded hem is provided. The invention is not limited to the shown embodiment but a plurality of variance are possible within the scope of the claims.

A device for folding at least one edge of a fabric for making a single or a double hem, said fabric edge being passed through shaping means contained in the device. The object of the invention is to provide a folding device, which within a relatively large area with respect to the most common fabrics, is insensitive to variations in thickness of the fabric, whether several fabric edges are to be folded simultaneously or whether transverse seem with considerable thickness occur. This object has been solved by the fact that the shaping means comprises portions of at least one endless, driven band, which is twisted in correspondance with the gradual folding of the fabric edge during the transport thereof through the device and said band being arranged to cooperate with at least one fixed rule arranged in direct connection with at least a part of the band portions.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2004-311927, filed on Oct. 27, 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 semiconductor manufacturing apparatus, a liquid container and a semiconductor device manufacturing method. [0004] 2. Related Art [0005] A semiconductor device such as a NAND flash memory is required to bury a silicon oxide film in a trench having a high aspect ratio so as to form deep STI (shallow trench isolation) in a narrow region. [0006] To meet this demand, a film formation technique for using both an HDP (high density plasma) film and an SOG (spin on glass) film has been developed (see Japanese Patent No. 3178412). According to this technique, a silicon oxide film is deposited by HDP-CVD (chemical vapor deposition), and a film coated with a perhydropolysilazane liquid (hereinafter,“PSZ (Polysilazane)”) is coated on the silicon oxide film by spin coating. The coated film is then silicified by a cure treatment. It is thereby possible to bury the silicon oxide film in a trench having a high aspect ratio. [0007] FIG. 14 is a conceptual view showing a conventional SOG step. Normally, a bottled PSZ liquid filled with nitrogen is commercially available. When a bottle cap is opened at a time of a used PSZ bottle being replaced by a new one, the air never fails to enter the bottles. In addition, during the replacement, the air may possibly enter a PSZ liquid supply nozzle from a tip end of the PSZ liquid supply nozzle. If so, the PSZ liquid unavoidably contacts with the air. [0008] The PSZ developed to be silicified at a temperature as low as about several hundred Celsius (° C.) can react with water and oxygen as represented by Chemical Formula 1, and can be solidified even at a room temperature when being exposed to the atmosphere. [0000] —(SiH 2 NH) n —+2nO→nSiO 2 +nNH 3   (Formula 1) [0009] When the PSZ is solidified in a piping from a PSZ container to a discharge nozzle, the solidified PSZ fixedly adheres onto a semiconductor substrate after being discharged together with the PSZ-coating liquid, thereby disadvantageously causing bulges, divots, and streaks. Even if the solidified PSZ is not formed, the air mixed into the piping and discharged onto the semiconductor substrate as air bubbles may possibly cause the bulges, divots, and streaks. Furthermore, the solidified PSZ may possibly damage the semiconductor substrate and a polishing cloth or cause a contamination during CMP (Chemical Mechanical Polish) process. [0010] When the PSZ remains in the used container, the PSZ reacts with water and oxygen to generate ammonium (NH 3 ) and silane (SiH 4 ). The ammonium and silane bring about considerably serious environmental and safety problems. It is, therefore, difficult to manage and handle the PSZ and the PSZ container in manufacturing of semiconductor products. [0011] In these circumstances, therefore, a semiconductor manufacturing apparatus, which airtightly transports a liquid to be coated on a substrate from a container to a discharge portion and suppresses the liquid from coming in contact with the air when the container is replaced by another one, has been desired. [0012] Furthermore, a liquid container detachable from the semiconductor manufacturing apparatus, which airtightly transports the liquid to be coated on the substrate from the container to the discharge portion and suppresses the liquid from coming in contact with the air when the container is replaced by another one, has been desired. SUMMARY OF THE INVENTION [0013] A semiconductor manufacturing apparatus according to an embodiment of the present invention comprises a discharge portion discharging a coating liquid onto a substrate; a gas supply tube supplying an inert gas into a liquid container that contains the coating liquid, and pressurizing an interior of the liquid container; a coating liquid supply tube airtightly supplying the coating liquid from the liquid container to the discharge portion using pressurization from the gas supply tube; a first connecting portion capable of attaching and detaching the liquid container to and from the coating liquid supply tube; a second connecting portion capable of attaching and detaching the liquid container to and from the gas supply tube; and a solvent supply tube supplying a solvent, which can dissolve the coating liquid, to the first connecting portion. [0014] A semiconductor manufacturing apparatus according to an embodiment of the present invention comprises a discharge portion discharging a coating liquid onto a substrate; a gas supply tube supplying an inert gas into a liquid container that contains the coating liquid, and pressurizing an interior of the liquid container; a coating liquid supply tube airtightly supplying the coating liquid from the liquid container to the discharge portion using pressurization from the gas supply tube; a first connecting portion capable of attaching and detaching the liquid container to and from the coating liquid supply tube; a second connecting portion capable of attaching and detaching the liquid container to and from the gas supply tube; and a liquid bath including the solvent capable of dissolving the coating liquid, [0015] wherein the first connecting portion and the second connecting portion are present in the liquid bath. [0016] A liquid container according to an embodiment of the present invention which contains a coating liquid and which is undesirable to expose to the atmosphere before utilizing for semiconductor manufacturing, the liquid container being attachable to or detachable from a semiconductor manufacturing apparatus, wherein [0017] the liquid container seals a coating liquid and a protection liquid, which is lower specific gravity than that of the coating liquid and does not react with the coating liquid, in a pressurized atmosphere with an inert gas higher than the atmospheric pressure. [0018] A semiconductor manufacturing method using a semiconductor manufacturing apparatus according to an embodiment of the present invention comprises a discharge portion discharging a coating liquid onto a substrate; a gas supply tube pressurizing an interior of the liquid container with an inert gas; a coating liquid supply tube airtightly supplying the coating liquid from the liquid container to the discharge portion using pressurization from the gas supply tube; a first connecting portion capable of attaching and detaching the liquid container to and from the coating liquid supply tube; a second connecting portion capable of attaching and detaching the liquid container to and from the gas supply tube; and an exhaust tube capable of reducing an internal pressure of the coating liquid supply tube including the first connecting portion: [0019] the method comprising: [0020] attaching the liquid container to the first connecting portion and the second connecting portion; [0021] supplying the inert gas to the liquid container via the gas supply tube, thereby carrying the coating liquid to the discharge portion via the coating liquid supply tube; [0022] discharging the coating liquid to the substrate from the discharge portion; [0023] reducing an internal pressure of the liquid container via the exhaust tube and the second connecting portion after discharging the coating liquid; and [0024] returning the coating liquid in the first connecting portion and the liquid supply tube to the liquid container by using the pressure in the liquid container. BRIEF DESCRIPTION OF THE DRAWINGS [0025] FIG. 1 is a schematic diagram of a semiconductor manufacturing apparatus and a PSZ container according to a first embodiment of the present invention; [0026] FIG. 2 shows a PSZ container 20 ; [0027] FIG. 3 shows an operation for detaching the PSZ container 20 ; [0028] FIG. 4 is a flowchart that shows a flow of an operation for detaching the PSZ container 20 ; [0029] FIG. 5 is a flowchart that shows a flow of an operation for attaching the PSZ container 20 ; [0030] FIG. 6 is a schematic diagram of a semiconductor manufacturing apparatus and a PSZ container according to a second embodiment of the present invention; [0031] FIG. 7 is a cross-sectional view of a PSZ container according to the second embodiment; [0032] FIG. 8 is a cross-sectional view of a PSZ container according to the second embodiment; [0033] FIG. 9 is a cross-sectional view of a PSZ container according to a third embodiment of the present invention; [0034] FIG. 10 is a schematic diagram of a semiconductor manufacturing apparatus and a PSZ container according to a fourth embodiment of the present invention; [0035] FIG. 11 is a schematic diagram of a semiconductor manufacturing apparatus and a PSZ container according to a fifth embodiment of the present invention; [0036] FIG. 12 is a schematic diagram of a semiconductor manufacturing apparatus and a PSZ container according to a sixth embodiment of the present invention; [0037] FIG. 13 is a table that shows effects of the respective embodiments of the present invention; and [0038] FIG. 14 is a schematic diagram showing a conventional SOG step. DETAILED DESCRIPTION OF THE INVENTION [0039] Hereafter, exemplary embodiments of the present invention will be described more specifically with reference to the drawings. Note that the invention is not limited to the embodiments. First Embodiment [0040] FIG. 1 is a schematic diagram of a semiconductor manufacturing apparatus 10 and a PSZ container 20 according to a first embodiment of the present invention. The semiconductor manufacturing apparatus 10 is an apparatus for dropping a PSZ liquid from a discharge nozzle onto a semiconductor substrate, and spreading the PSZ liquid on the semiconductor substrate by spin coating at an SOG step. [0041] The semiconductor manufacturing apparatus 10 includes a coating liquid discharge portion (not shown), a PSZ supply tube 12 serving as a coating liquid supply tube, a dibutyl ether supply tube (hereinafter, “DBE supply tube”) 15 serving as a solvent supply tube, a helium supply tube (hereinafter, “He supply tube”) 16 serving as a gas supply tube, an exhaust tube 17 , and branch tubes 13 and 14 . Since the discharge portion may be identical to the discharge nozzle shown in FIG. 14 , it is not shown in FIG. 1 . [0042] The semiconductor manufacturing apparatus 10 also includes a connector C 1 a serving as a first connecting portion and a connector C 2 a serving as a second connecting portion. The PSZ supply tube 12 is connected to the connector C 1 a through a valve 102 . One end of the branch tube 13 is connected to the PSZ supply tube 12 between the valve 102 and the connector C 1 a through a valve 103 . The other end of the branch tube 13 is connected to one end of the branch tube 14 through a valve 104 , and also connected to the DBE supply tube 15 through a valve 105 . [0043] The He supply tube 16 is connected to the connector C 2 a through a valve 106 . The other end of the branch tube 14 is connected to the He supply tube 16 between the valve 106 and the connector C 2 a, and the exhaust tube 17 is connected to the He supply tube 16 through a valve 107 . A vacuum pomp, e.g., a turbomolecular pump, not shown, is connected to the exhaust pipe 17 . [0044] As shown in FIG. 2 , the PSZ container. 20 includes a pair of connectors C 1 b and C 2 b connectable to the connectors C 1 a and C 2 a of the semiconductor manufacturing apparatus 10 , respectively. The PSZ container 20 can be thereby attached to or detached from the PSZ supply tube 12 and the He supply tube 16 . [0045] The PSZ container 20 also includes a PSZ outlet tube 21 provided from the connector C 1 b to neighborhoods of a bottom of the container 20 , and a He inlet tube 22 provided from the connector C 2 b to neighborhoods of an upper surface of the container 20 . Valves 101 and 100 are provided at the PSZ outlet tube 21 near the connector C 1 b and the He inlet tube 22 near the connector C 2 b, respectively, whereby an interior of the PSZ container 20 is shut off from the atmosphere. [0046] The PSZ container 20 is withdrawn in a sealed state after usage and recyclable by filling a PSZ liquid again into the container 20 . An inert gas as well as the PSZ liquid is filled into the PSZ container 20 with the, inert gas pressurized at a slightly higher pressure than an atmospheric pressure. By doing so, the air is not mixed into the PSZ container 20 . The PSZ liquid is contained in the PSZ container 20 up to a portion near the valve 100 but contained so as not to reach the valve 100 . It is thereby possible to prevent air bubbles from being generated in the PSZ liquid. The PSZ liquid is contained in the PSZ container 20 in a state, for example, in which the PSZ liquid is dissolved into a solvent such as dibutyl ether (hereinafter, “DBE”). [0047] The inert gas filled into the PSZ container 20 is preferably the same as the inert gas, i.e., helium gas supplied to the semiconductor manufacturing apparatus 10 for the following reasons. The helium possesses a property that it is insoluble with an organic solvent such as the PSZ or DBE, and the helium is less expensive than the other inert gas such as xenon. The PSZ container 20 and the semiconductor manufacturing apparatus 10 are preferably made of stainless steel (SUS). However, the material for the PSZ container 20 and the semiconductor manufacturing apparatus 10 is not limited to SUS but may be an arbitrary material that has good airtightness, that does not react with the PSZ, and that does not cause a metal contamination. PSZ Supply Operation [0048] When the PSZ liquid is supplied to the discharge portion, the PSZ supply tube 12 and the He supply tube 16 are used but the DBE supply tube 15 and the exhaust tube 17 are not used. Due to this, the valves 100 , 101 , 102 , and 106 are open whereas the valves 103 , 104 , 105 , and 107 are closed. In this state, the He supply tube 16 supplies the He gas to the PSZ container 20 to pressurize an interior of the PSZ container 20 . An internal atmospheric pressure of the PSZ container 20 is made thereby higher than a surrounding atmospheric pressure, so that the PSZ liquid is supplied to the discharge portion through the PSZ supply tube 12 . At this time, the PSZ supply tube 12 airtightly supplies the PSZ liquid from the PSZ container 20 to the discharge portion. The discharge portion discharges the coating liquid onto the semiconductor substrate (see FIG. 14 ). PSZ Container Detachment Operation [0049] FIG. 3 shows a manner of detaching the PSZ container 20 from the semiconductor manufacturing apparatus 10 . FIG. 4 is a flowchart that shows a flow of an operation for detaching the PSZ container 20 . With reference to FIGS. 3 and 4 , the operation for detaching the PSZ container 20 will be described. [0050] When the PSZ liquid is supplied to the discharge portion and a residual amount of the PSZ liquid in the PSZ container 20 is small, it is necessary to replace the PSZ container 20 by a new PSZ container 20 . At this time, if the valves 100 , 101 , 102 , and 106 are simply closed to disconnect the connector C 1 a from the connector C 1 b and the connector C 2 a from the connector C 2 b, the PSZ liquid remaining in the PSZ supply tube 12 from the connector C 1 a to the valve 102 may possibly come in contact with the air. [0051] To prevent this contact, when the PSZ container 20 is detached, the valves 101 , 102 , and 106 are closed in this order and the valve 107 is opened (at a step S 10 ). At this step, since the valves 100 and 107 are open, the exhaust pipe 17 communicates with the PSZ container 20 while the valves other than the valves 100 and 107 are closed. The internal pressure of the PSZ container 20 is thereby reduced to about 600 Torr through the exhaust tube 17 (at a step 510 ). [0052] After the valve 107 is closed, the valves 105 , 103 , and 101 are opened in this order. At this time, the internal pressure of the PSZ container 20 is lower than the atmospheric pressure (about 760 Torr). Due to this, DBE is supplied into the PSZ container 20 through the DBE supply tube 15 , the branch tube 13 , the PSZ supply tube from the valve 102 to the connector C 1 a (hereinafter, the PSZ supply tube 12 in this section will be referred to as “piping 12 a ”), and the PSZ outlet tube 21 . The PSZ liquid remaining in the piping 12 a and the PSZ outlet tube 21 is thereby forced into the PSZ container 20 . At the same time, the piping 12 a and the PSZ outlet tube 21 are filled with the DBE (at a step S 30 ). [0053] After the internal pressure of the PSZ container 20 is identical to the atmospheric pressure, the valves 100 and 105 are closed (at a step S 40 ). The valves 106 and 104 are then opened in this order. The He supply tube 16 thereby communicates with the PSZ container 20 through the branch tubes 14 and 13 . By supplying the pressurized He gas from the He supply tube 16 , the DBE remaining in the branch tube 13 , the piping 12 a, and the PSZ outlet tube 21 is forced into the PSZ container 20 (at a step 560 ). When the internal pressure of the PSZ container 20 reaches at about 900 Torr, the valves 103 and 106 are closed (at a step. 570 ). Thereafter, the connector C 1 a is disconnected from the connector C 1 b, and the connector C 2 a is disconnected from the connector C 2 b, and the used PSZ container 20 is detached from the semiconductor manufacturing apparatus 10 (at a step S 80 ). [0054] Since the He gas at the higher pressure than the atmospheric pressure is filled into the used PSZ container 20 , the air is not mixed into the PSZ container 20 . It is, therefore, possible to prevent oxygen and water from reacting with the PSZ liquid in the PSZ container 20 . [0055] When the used PSZ container 20 is detached from the semiconductor manufacturing apparatus 10 , the PSZ supply tube 12 from the valve 102 to the discharge portion is filled with the PSZ liquid. The piping 12 a and a piping (hereinafter, “piping 21 a ”) from the connector C 1 b of the PSZ container 20 to the valve 101 are exposed to the atmosphere. In this embodiment, however, the piping 12 a is washed by the DBE used as the solvent for the PSZ liquid in the PSZ container 20 , no PSZ liquid remains in the piping 12 a. Therefore, no PSZ solid matter is generated in the pipings 12 a and 21 a. PSZ Container Attachment Operation [0056] FIG. 5 is a flowchart that shows a flow of an operation for attaching the PSZ container 20 to the semiconductor manufacturing apparatus 10 . With reference to FIGS. 1 and 5 , an operation for attaching the new PSZ container 20 to the apparatus 10 will be described. [0057] Although no PSZ liquid is contained in the piping 21 a of the new PSZ container 20 , the piping 21 a is exposed to the atmosphere. Due to this, it is necessary to take care not to contact the air present in the pipings 12 a and 21 a with the PSZ liquid. [0058] The new PSZ container 20 is connected to the semiconductor manufacturing apparatus 10 (at a step S 90 ). At this time, all the valves 100 to 107 are closed. The valves 107 , 104 , and 103 are then opened in this order. Internal pressures of the piping 12 a and the branch tubes 103 and 104 are reduced to 10 −4 to 10 −5 Torr (at a step S 100 ). [0059] After closing the valves 107 and 104 in this order, the valve 101 is opened. At this time, a piping including the piping 12 a from the valve 101 to the valve 103 and the branch tube 13 are in a low pressure state close to a vacuum. Therefore, the PSZ liquid in the PSZ container 20 promptly reaches close to the valve 104 (at a step S 110 ). [0060] After closing the valve 103 , the valve 105 is opened. The PSZ liquid in the branch tube 13 is thereby mixed with the DBE (at a step S 120 ). [0061] Next, the valve 106 is opened, the He gas is supplied into a crisscross piping partitioned by the valves 100 , 107 , 106 , and 104 , and an internal pressure of the crisscross piping is thereby returned to about 600 Torr (at a step S 130 ). After closing the valve 106 , the valve 100 is opened. At this time, the internal pressure of the crisscross piping partitioned by the valves 100 , 107 , 106 , and 104 is slightly lower than the atmospheric pressure. Due to this, a mixture liquid of the PSZ, and the DBE in the branch tube 13 is returned to at least the piping 12 a (at a step S 140 ). Since the DBE liquid is used as the solvent for the PSZ liquid in the PSZ container 20 , no problem occurs even if a small amount of the mixture liquid enters the PSZ container 20 . It is noted that He air bubbles are sometimes mixed into this mixture liquid of the PSZ and the DBE. [0062] After closing the valve 103 , the valve 106 is opened (at a step S 150 ). The PSZ liquid in the PSZ container 20 can be thereby supplied to the discharge portion through the PSZ supply tube 12 . Since the initially supplied liquid is either the mixture liquid of the PSZ and the DBE or the mixture liquid containing the He air bubbles, the liquid is disposed of. [0063] When the amount of the PSZ liquid in the PSZ container 20 is reduced, the detachment operation and the attachment operation for detaching and attaching the PSZ container 20 are repeatedly carried out according to the steps S 10 to S 150 . As described above, according to the first embodiment, the PSZ liquid can be supplied to the discharge portion without exposure to the air. [0064] In recent years, following an increase in the aspect ratio of STI, it has been difficult to bury the silicon oxide film in the trench. The STI in the NAND flash memory is, in particular, high in aspect ration as compared with a logic circuit, and required to bury the silicon oxide film in a non-tapered trench. [0065] When the present embodiment is applied, such defects as bumps, divots, and streaks can be prevented even at manufacturing steps of a NAND flash memory with a trench having an opening width of, for example, 90 to 70 nm. This can contribute to an improvement in the yield of semiconductor devices. [0066] Furthermore, in the used PSZ container 20 , the residual liquid does not contact with the atmosphere and no hazardous and ignitable gas such as ammonium or silane is generated. [0067] The valves 102 to 105 are preferably gate valves, e.g., block valves, without any excessive space at branch portions. Second Embodiment [0068] FIG. 6 is a schematic diagram of a semiconductor manufacturing apparatus 40 and a PSZ container 50 according to a second embodiment of the present invention. The semiconductor manufacturing apparatus 40 differs from the semiconductor manufacturing apparatus shown in FIG. 14 in that a tip end of a PSZ supply tube 42 is formed into a “J” shape. The other constituent elements of the semiconductor manufacturing apparatus 40 may be identical to those of the semiconductor manufacturing apparatus shown in FIG. 14 . The PSZ container 50 contains not only a PSZ liquid but also a protection liquid 52 that shuts off the PSZ liquid from the atmosphere. The other constituent elements of the PSZ container 50 may be identical to those of the PSZ container shown in FIG. 14 . [0069] In the semiconductor manufacturing apparatus shown in FIG. 14 , an end of the PSZ supply tube is directed downward. Due to this, when the PSZ container is attached to the semiconductor manufacturing apparatus, air bubbles tend to be mixed into the PSZ supply tube. When the air bubbles are oxygen or water bubbles, they may disadvantageously cause the PSZ liquid to be solidified. When the air bubbles are inert gas bubbles such as helium bubbles, the PSZ liquid is disadvantageously difficult to discharge from the discharge portion. [0070] In the semiconductor manufacturing apparatus 40 according to the second embodiment, by contrast, an end of the PSZ supply tube 42 is directed upward. This can make it more difficult to mix air bubbles into the PSZ supply tube 42 when the PSZ container 50 is attached to the semiconductor manufacturing apparatus 40 . It is noted that the PSZ container 50 is attached to the semiconductor manufacturing apparatus 40 after a valve 501 is closed. By doing so, even while the PSZ container 50 is being attached to the apparatus 40 , the PSZ liquid remains at the tip end of the PSZ supply tube 42 . [0071] FIGS. 7 and 8 are cross-sectional views of the PSZ container 50 according to the second embodiment. FIG. 7 shows the PSZ container 50 when being attached to the semiconductor manufacturing apparatus 40 , and FIG. 8 shows the PSZ container 50 when being detached from the semiconductor manufacturing apparatus 40 . [0072] Desirable conditions for the protection liquid 52 that covers the PSZ in the PSZ container 50 are: no reaction with the PSZ liquid (condition 1), lower specific gravity than that of the PSZ liquid and no mixture with the PSZ liquid (condition 2), higher wettability with an inner wall of the PSZ container 50 than that of the PSZ liquid (condition 3), and non-inclusion of carbon (C) in impurities (condition 4). The conditions 1 and 2 are necessary conditions. Examples of a material that satisfies the conditions 1 and 2 include straight-chain-hydrocarbon and cyclic cyclohexane. [0073] When the protection liquid 52 satisfies the conditions 1 and 2, the protection liquid 52 can cover a liquid level of the PSZ liquid in the PSZ container 50 . When the protection liquid 52 satisfies the conditions 3, the protection liquid 52 can cover the inner wall of the PSZ container 50 and the residual PSZ liquid tends to reside on a bottom of the PSZ container 50 as shown in FIG. 8 . It is thereby possible to ensure that the PSZ liquid is shut off from the atmosphere. The condition 4 is intended to eliminate carbon that may have a conductive type of either p or n as much as possible. [0074] In the second embodiment, when the new PSZ container 50 is attached to the semiconductor manufacturing apparatus 40 , the air enters the PSZ container 50 . However, since the protection liquid 52 covers the surface of the PSZ, it is possible to prevent contact of the PSZ with the air. Further, when the used PSZ container 50 is detached from the semiconductor manufacturing apparatus 40 , it is possible to prevent the contact of the PSZ liquid with the air since the protection film 52 covers the surface of the PSZ. In addition, while the PSZ liquid is being supplied, the liquid level of the PSZ is lowered. However, since the protection liquid 52 has a favorable wettability, the protection liquid 52 even covers the surface of the PSZ adhering to the inner wall of the PSZ container 50 . [0075] As shown in FIG. 8 , even if the PSZ container 50 is temporarily held at a different location, the air in the PSZ container 50 does not contact with the PSZ liquid and no ammonium or silane is, therefore, generated in the PSZ container 50 . [0076] When the PSZ container 50 is attached to the semiconductor manufacturing apparatus 40 , the protection liquid 52 enters the PSZ supply tube 42 . However, since the specific gravity of the protection liquid 52 is lower than that of the PSZ liquid and the tip end of the PSZ supply tube 42 is J-shaped and directed upward, the protection liquid 52 surfaces on the tip end of the PSZ supply tube 42 . Therefore, the protection liquid 52 is not supplied to a discharge portion 44 . [0077] In the second embodiment, the protection liquid 52 may be also used in a waste liquid container provided below a spin coater. If so, a waste liquid is thereby out of contact with the air. The second embodiment is, therefore, more preferable in environmental and safety aspects. [0078] The semiconductor manufacturing apparatus 40 and the PSZ container 50 according to the second embodiment are relatively inexpensive and can be realized by simple changes in designs of the conventional semiconductor manufacturing apparatus and the conventional PSZ container, respectively. Third Embodiment [0079] FIG. 9 is a cross-sectional view of a semiconductor manufacturing apparatus 40 and a PSZ container 60 according to a third embodiment of the present invention. The PSZ container 60 according to the third embodiment includes a narrow opening portion 61 and a concave portion 63 that can accept a J-shaped tip end E of a PSZ supply tube 42 . The semiconductor manufacturing apparatus 40 is identical to the semiconductor manufacturing apparatus 40 according to the second embodiment. [0080] According to the third embodiment, since the opening portion 61 is narrow, an area by which a PSZ liquid contacts with the air can be made small. In addition, by inserting the tip end E of the PSZ supply tube 42 into the concave portion 63 , the PSZ liquid can be made most use of to the end. [0081] The semiconductor manufacturing apparatus 40 and the PSZ container 60 according to the third embodiment are also relatively inexpensive and can be realized by simple changes in designs of the conventional semiconductor manufacturing apparatus and the conventional PSZ container, respectively. Fourth Embodiment [0082] FIG. 10 is a schematic diagram of a semiconductor manufacturing apparatus 70 and a PSZ container 80 according to a fourth embodiment of the present invention. The semiconductor manufacturing apparatus 70 differs from the semiconductor manufacturing apparatus shown in FIG. 14 in that the apparatus 70 includes a liquid bath 73 that contains a DBE liquid. A PSZ supply tube 72 and a He supply tube 71 are inserted into the liquid bath 73 , and a tip end of the PSZ supply tube 72 and that of the He supply tube 71 are arranged below a liquid level of the DBE liquid. [0083] Female connectors 75 are provided at tip ends of the He supply tube 71 and the PSZ supply tube 72 , respectively, and corresponding male connectors 85 having a valve are provided at the PSZ container 80 . By one-touch connection between the female connectors 75 and the corresponding male connectors 85 , the PSZ container 80 is connected to the He supply tube 71 and the PSZ supply tube 72 . [0084] Attachment and detachment of the PSZ container 80 to and from the semiconductor manufacturing apparatus 70 are executed in the DBE liquid. Therefore, the air does not contact with the PSZ liquid. Since the DBE liquid is contained in the PSZ container 80 as a solvent for the PSZ liquid, no problem occurs even if a small amount of the DBE liquid pis mixed into the PSZ container 80 . [0085] Furthermore, the semiconductor manufacturing apparatus and the PSZ container 80 according to the fourth embodiment are also relatively inexpensive, and can be realized by simple changes in designs of the conventional semiconductor manufacturing apparatus and the conventional PSZ container, respectively. [0086] A material for the PSZ container 80 may be a flexible material such as polyethylene in place of glass. When the PSZ container 80 consists of the flexible material and the air is mixed into the male connectors 85 , the air can be easily removed by an operator's compressing the PSZ container 80 by an operator's hand after the PSZ container 80 is dipped into the liquid bath 73 . It is noted that the DBE liquid does not flow backward into the PSZ container 80 since the respective male connectors 85 include valves. Fifth Embodiment [0087] FIG. 11 is a schematic diagram of a semiconductor manufacturing apparatus and a PSZ container 80 according to a fifth embodiment of the present invention. The fifth embodiment differs from the fourth embodiment in a shape of a liquid bath. 91 . Other constituent elements in the fifth embodiment may be identical to those in the fourth embodiment. A region R 1 of the liquid bath 91 , into which a tip end of a He supply tube 71 and that of a PSZ supply tube 72 are inserted, is filled with a DBE liquid. Therefore, a PSZ liquid does not contact with not only the air but also a gas such as He. [0088] A region R 2 of the liquid bath 91 has an upper opening portion. The PSZ container 80 can be attached to the He supply tube 71 and the PSZ supply tube 72 by operator's inserting the PSZ container 80 into the liquid bath 91 from this opening portion. The liquid bath 91 includes a porthole 93 . The operator can, therefore, connect the PSZ container 80 to the He supply tube 71 and the PSZ supply tube 72 while viewing the liquid bath 91 from the porthole 93 . Sixth Embodiment [0089] FIG. 12 is a schematic diagram of a semiconductor manufacturing apparatus and a PSZ container 81 according to a sixth embodiment of the present invention. In the fourth and the fifth embodiments, the attachment and detachment of the PSZ container are executed in the DBE liquid. In the sixth embodiment, the attachment and detachment of the PSZ container are executed in a He gas atmosphere. [0090] An upper portion of a region R 1 of the PSZ container 81 is filled with the He gas. A liquid bath 92 includes a supply port 350 for supplying the He gas and an exhaust port 351 for exhausting the air or the like mixed into the liquid bath 92 together with the He gas. By so constituting, even if the gas other than the He gas is mixed into the PSZ container 81 while the PSZ container 81 is being replaced with another container 81 , the gas can be exhausted. [0091] In the semiconductor manufacturing apparatus, a connector C 3 a is connected to a PSZ supply tube 312 through a valve 310 , and also connected to a balloon 360 through a valve 309 . A connector C 4 a is connected to a He supply tube 316 . The balloon 360 consists of, for example, a rubber having a high elasticity and a low reaction with the PSZ liquid. The balloon 360 is filled with the PSZ liquid in advance. A valve 307 is provided at the He supply tube 316 , and an exhaust tube 317 is connected between the valve 307 and the connector C 4 a through a valve 308 . [0092] A PSZ outlet tube 321 and a He inlet tube 322 of the PSZ container 81 include two valves 304 and 306 and two valves 303 and 305 , respectively. Connectors C 3 b and C 4 b of the PSZ outlet tube 321 and the He inlet tube 322 are formed to be directed downward. The PSZ outlet tube 321 from the PSZ container 81 to the valve 304 is filled with the PSZ liquid in advance, and a piping between the valves 303 and 305 and a piping between the valves 304 and 306 are each filled with a pressurized He gas in advance. [0093] An operation for attaching the PSZ container 81 to the semiconductor manufacturing apparatus will be described. The PSZ container 81 is moved into the liquid bath 92 so that the connectors C 3 b and C 4 b are provided in the He gas atmosphere in the region R 1 (at a step S 300 ). At this time, the air may possibly remain in a piping from the valve 306 to the connector C 3 b and a piping from the valve 305 to the connector C 4 b . Considering this, by opening the valves 305 and 306 , the pressurized He gas is ejected (at a step S 310 ). By doing so, the air is discharged to the outside of the connectors C 3 b and C 4 b. Since the air is higher in specific gravity than the He gas, the air is moved to a liquid level of the DBE liquid and exhausted from the exhaust port 351 . [0094] Thereafter, the connector C 3 a is connected to the connector C 3 b and the connector C 4 a is connected to the connector C 4 b (at a step S 320 ). At this time, the valves 307 , 308 , 309 , and 310 are closed. The valves 309 and 308 are then opened in this order (at a step S 330 ). The balloon 360 filled with the PSZ liquid is thereby contracted and the He gas residing in a piping from the valve 304 to the valve 309 is returned into the PSZ container 81 . [0095] After closing the valves 308 and 309 in this order, the valves 307 and 310 are opened in this order (at a step S 340 ). The He supply tube 316 thereby supplies the He gas into the PSZ container 81 and the PSZ liquid is supplied to a discharge portion through the PSZ supply tube 312 . [0096] When the PSZ container 81 is to be detached from the semiconductor manufacturing apparatus, then the valve 310 is closed, and the valve 309 is closed after the balloon 360 is filled with the PSZ liquid to some degree. After closing all the valves 303 to 308 , the PSZ container 81 is detached. [0097] According to the fifth embodiment, the PSZ container 81 can be replaced by a new PSZ container 81 in an environment shut off from the air while preventing mixture of the He gas. [0098] As described above, in the embodiments, it is preferable that the PSZ liquid is discharged onto a dummy wafer before being coated on a desired wafer. This is because the DBE liquid may possibly enter the PSZ container 81 during the replacement. [0099] The embodiments may be executed in combination. For example, the PSZ container 50 shown in FIGS. 7 and 8 can be applied to any one of the first and the third to the fifth embodiments. [0100] FIG. 13 is a table that shows effects of the respective embodiments. In the table of FIG. 13 , the numbers of particles generated when the PSZ liquid is coated on the semiconductor substrate at the SOG step are shown. In the conventional technique shown in FIG. 14 , many particles having respective particle diameters are generated. In the first to the sixth embodiments, particles having particle diameters of 0.2 to 1.0 μm are hardly generated. According to the embodiments of the present invention, therefore, it is expected to improve the yield of semiconductor devices. [0101] In the respective embodiments of the present invention, the coating liquid is not limited to the PSZ liquid but may be any coating liquid for forming a silica-containing film or the like.

A semiconductor manufacturing apparatus comprises a discharge portion discharging a coating liquid onto a substrate; a gas supply tube supplying an inert gas into a liquid container that contains the coating liquid, and pressurizing an interior of the liquid container; a coating liquid supply tube airtightly supplying the coating liquid from the liquid container to the discharge portion using pressurization from the gas supply tube; a first connecting portion capable of attaching and detaching the liquid container to and from the coating liquid supply tube; a second connecting portion capable of attaching and detaching the liquid container to and from the gas supply tube; and a solvent supply tube supplying a solvent, which can dissolve the coating liquid, to the first connecting portion.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/219,613, filed Sep. 16, 2015. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates generally to tiedown and other load and cargo securing devices and systems, and particularly to a load securing device for lift trucks that provides positive attachment to the base of an object being carried on or by the forks of a lift truck. [0004] 2. Description of the Related Art [0005] Various lift trucks have been developed in the past, with most having adjustable forks extending from the forward end thereof. Perhaps the best known of these devices is the forklift wherein the vehicle includes a prime mover (generally an internal combustion engine, but often an electric motor) for moving the vehicle from place to place, with the prime mover also powering a hydraulic pump to provide power for the operation of the lift forks. [0006] Another type of lift truck is the powered hand truck, a powered vehicle having two main wheels that are steered by independent braking or drive. A small platform is provided at the rear of the vehicle for the operator. Such a powered lift truck is disclosed in U.S. Pat. No. 7,597,522 issued to Steven Borntrager et al. on Oct. 6, 2009, which is incorporated herein by reference in its entirety. [0007] Still another type of lift truck is the pallet jack, in which the lift forks are generally manually powered by a hand or foot pump or the like, although they may be powered by another power source in some variations. All of these devices have in common a pair of lift forks extending from the forward end thereof. [0008] A chronic problem with such forked lift trucks and vehicles is that the load being carried is generally not positively secured to the vehicle. Forklifts commonly provide for the rear tilt of the entire forklift carriage, in order to reduce the chance of the load slipping forward off the forks. However, this is not an absolute remedy for this potential hazard, and other lift trucks may not provide for such rearward tilt of the forks at all. [0009] Thus a load securing device for lift trucks solving the aforementioned problems is desired. SUMMARY OF THE INVENTION [0010] The load securing device for lift trucks comprises various embodiments adapted for installation upon powered hand trucks, forklifts, and pallet jacks. Each embodiment includes an upright for attachment to the lift truck structure, the upright having a tensioner (e.g., strap ratchet, etc.) installed at its upper end opposite the forks of the lift truck. A tensioning element (e.g., tiedown or nylon strap, etc.) passes through the tensioner, with a chain and hook extending from the distal end of the tensioning element. Two load securing devices are installed as a pair on the lift structure. The hooks of the two load securing devices are hooked to the load being carried on the forks of the lift truck, and the tensioners are tightened to pull and hold the load adjacent to the vertical structure of the lift truck at the back of the forks. The load securing device is particularly well-suited for use with the powered hand truck as described in U.S. Pat. No. 7,597,522 for securing a small portable building structure to the powered hand truck for transport or relocation, although it is adaptable to numerous other types of lift trucks and loads. [0011] These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a detailed environmental elevation view of a load securing device for lift trucks according to the present invention, illustrating its operation. [0013] FIG. 2 is an environmental perspective view of the load securing device for lift trucks of FIG. 1 , showing the device installed upon a powered hand truck. [0014] FIG. 3 is an environmental perspective view of a second embodiment of the load securing device for lift trucks according to the present invention, showing the device installed upon the forks of a forklift. [0015] FIG. 4 is an environmental perspective view of a third embodiment of the load securing device for lift trucks according to the present invention, showing the device installed upon a pallet jack. [0016] FIG. 5 is a front elevation view of the load securing device for lift trucks of the embodiment of FIG. 1 , illustrating the angular disposition of the uprights. [0017] FIG. 6 is a front elevation view of a fourth embodiment of the load securing device for lift trucks according to the present invention, comprising a crossmember extending across the top of a single upright member. [0018] FIG. 7 is a front elevation view of a fifth embodiment of the load securing device for lift trucks according to the present invention, wherein the crossmember and single upright member have a cruciform configuration. [0019] FIG. 8 is a detailed perspective view of one embodiment of a hook member for installation and use with the load securing device for lift trucks according to the present invention. [0020] FIG. 9 is a detailed perspective view of another embodiment of a hook member for installation and use with the load securing device for lift trucks according to the present invention. [0021] Similar reference characters denote corresponding features consistently throughout the attached drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0022] The load securing device for lift trucks comprises various embodiments of an attachment for powered lift trucks, forklifts, pallet jacks, and similar machines having fork tines extending forwardly therefrom, for the secure carriage of large bulky objects thereon. The various embodiments differ in the length or height of the rigid uprights used to attach the devices to the lift truck, depending upon the type or configuration of lift truck, and the configuration of the hook members for attaching to the load. [0023] FIGS. 1 and 2 of the drawings illustrate a first embodiment of the load securing device 100 , installed on a powered hand truck T. The powered hand truck T includes a mast M with a laterally disposed crossmember C at the bottom end thereof, with two laterally spaced fork tines TT extending forwardly from the crossmember C (only one such tine TT is visible in the drawings). Two such load securing devices 100 are preferably installed as a pair, with the two devices 100 being laterally separated from one another and attached to the crossmember C adjacent the respective fork tines TT to extend upward from the crossmember C. Each load securing device 100 includes an upright 102 having a lower end 104 welded or otherwise affixed (e.g., rigidly and immovably affixed) to the crossmember C, and an opposite upper end 106 . The upright 102 is preferably formed from a length of rectangular section steel channel with a plate welded across the span of the open channel at the upper end portion 106 thereof to close the channel at the upper end portion, with the resulting closed box structure remaining open at its extreme end. Other materials may be used as desired. [0024] A tensioner 108 , e.g., a tiedown strap ratchet or the like, is affixed (e.g., bolted, welded, etc.) to the upper end 106 of the upright 102 , e.g., opposite the forwardly oriented truck fork tines TT. The tensioner 108 is oriented so that its takeup reel is oriented downward to allow its flexible tension element 110 (referred to as a tiedown strap, a ratchet strap, or a nylon strap) to wind and unwind downward therefrom, generally along the length of the upright 102 . Each tension element 110 has a distal end 112 , with a load attachment extending therefrom. The load attachment may comprise a length of chain 114 having a distal end 116 opposite its attachment to the distal end 112 of the tension element 110 . A hook member 118 extends from the chain 114 for removable attachment to the structure of the load L being carried or moved by the powered lift truck T. The hook member 118 may comprise a heavy length of bar stock cut, forged, or otherwise formed of durable steel, as shown in detail in FIG. 8 of the drawings, or other suitable component as desired. FIG. 9 illustrates an alternative hook member 120 , formed of a section of heavy rectangular plate having a U-channel formed at one end. [0025] FIG. 3 of the drawings illustrates an alternative embodiment, designated as load securing device or device 200 . The only difference between the load securing device 200 and the load securing device 100 of FIGS. 1 and 2 is the length of the upright 202 . The load securing device 200 of FIG. 3 is installed upon an otherwise conventional forklift F having a mast, a carriage R movably mounted on the mast, and laterally spaced tines FT attached to the carriage R. Each tine FT has a vertical leg A having an upper end UE and an opposite lower end LE. [0026] The lower end 204 of each upright 202 is rigidly affixed (e.g., by welding) to the upper end UE of a corresponding vertical leg A of a tine FT. As the vertical legs A have some substantial vertical extent, the uprights 202 need not be so long or tall as the uprights 102 of the embodiment of FIGS. 1 and 2 . Otherwise, the load securing device 200 includes the same components and structure as described further above for the embodiment 100 of FIGS. 1 and 2 , with a tensioner 108 , e.g., a tiedown strap ratchet or the like, rigidly and permanently affixed to the upper end or upper end portion 206 of the upright 202 to the back side thereof, i.e., opposite the forwardly oriented forklift tines FT. The tensioner 108 is oriented so that its takeup reel is oriented downward to allow its flexible tension element 110 (not visible in FIG. 3 , but comprising a tiedown strap or the like, as shown in FIGS. 1 and 2 ) to wind and unwind downward therefrom, generally along the length of the upright 202 and the tine's vertical leg A. Each tension element 110 has a distal end 112 (not shown in FIG. 3 ), with a load attachment extending therefrom. The load attachment may comprise a length of chain 114 having a distal end 116 opposite its attachment to the distal end 112 of the tension element 110 , with a hook member 118 (or alternatively, the hook member 120 shown in detail in FIG. 9 ) extending therefrom for removable attachment to the structure of the load L being carried or moved by the forklift F, as in the powered hand truck T of FIGS. 1 and 2 . The open ended channel configuration of the uprights 202 (or uprights 102 of FIGS. 1 and 2 ), shown in FIG. 3 , permits the distal end of the hook 118 (or other hook) to be hooked over the open upper end 206 of the upright 202 for convenient carriage of the hook and chain assembly, particularly when the tension element (e.g., tiedown strap) has been retracted onto or into the tensioner 108 . [0027] FIG. 4 of the drawings illustrates an alternative embodiment, designated as load securing device or device 300 . The load securing device 300 of FIG. 4 is installed upon a conventional pallet jack P having a rearward structure S with a pair of pallet jack tines PT extending forwardly therefrom. The lower ends 304 of the first and second uprights 302 are rigidly and immovably affixed (welding, etc.) to the structure S of the pallet jack P, and/or to the rearward ends of the two fork tines PT. The only difference between the load securing device 300 and the load securing device 200 of FIG. 3 is the length of the upright 302 , with the uprights 302 having lengths or heights similar to those of the uprights 102 of the embodiment 100 of FIGS. 1 and 2 . As the rearward ends of the two fork tines are quite close to the underlying surface, the lower ends 304 of the uprights 302 are also close to the underlying surface, with their upper ends 306 extending upward for some distance or length above their lower attachment ends 304 . [0028] Otherwise, the load securing devices 300 include the same components and structure as described further above for the embodiments 100 and 200 of FIGS. 1 through 3 , with each having a tensioner 108 , e.g., a tiedown strap ratchet or the like, rigidly affixed to the upper end or upper end portion 306 of the upright 302 to the back side thereof, i.e., opposite the forwardly oriented pallet jack tines PT. The tensioner 108 is oriented so that its takeup reel is oriented downward to allow its flexible tension element 110 to wind and unwind downward therefrom, generally along the length of the upright 302 . Each tension element 110 has a distal end 112 , with a load attachment extending therefrom. The load attachment may comprise a length of chain 114 having a distal end 116 opposite its attachment to the distal end 112 of the tension element 110 , with a hook member 118 (or alternatively, the hook member 120 shown in detail in FIG. 9 ) extending therefrom for removable attachment to the structure of the load being carried or moved by the pallet jack P, as in the powered hand truck T of FIGS. 1 and 2 . It will be noted in FIG. 4 that the hook member 120 is stowed by hooking its distal end into the open upper end 306 of the upright 302 , similarly to the stored disposition of the hook member 118 shown for the embodiment 200 illustrated in FIG. 3 . [0029] FIG. 5 of the drawings illustrates further details of the load securing device for lift trucks, particularly the embodiment 100 of FIGS. 1 and 2 . It will be noted that the forks TT of the powered lift truck T are not laterally adjustable, i.e., they define a fixed distance therebetween. In many instances, relatively large and wide loads must be supported by the two fork tines TT, as in the example illustrated in FIG. 1 . Accordingly, it is desirable to space the two hook members 118 or 120 relatively widely apart, in order to provide longer lateral arms from the center of the load to the attachments of the two hook members 118 or 120 to the load. It will be seen that this arrangement will spread the two tension elements 110 and their chains 114 laterally, which applies an outward lateral load on the two uprights 102 if those uprights are installed vertically to the crossmember C. [0030] Accordingly, the two uprights 102 are preferably installed so that their upper ends 106 are angled toward one another from the vertical (assuming the crossmember C is horizontal), as represented by the vertical lines V in FIG. 5 . This places the upper ends 106 of the two uprights 102 closer to one another and to the central mast M than their lower ends 104 , as shown by the angular displacements D in FIG. 5 . Thus, the outwardly angled tension elements 110 extend along paths substantially parallel to the two uprights 102 , as shown in FIG. 2 , thereby obviating or at least substantially reducing lateral forces on the uprights 102 . [0031] FIG. 5 also provides a front elevation view of an additional brace structure that may be installed with the load securing devices 100 . The two braces 122 extend between the lift truck structure, e.g., the crossmember C (shown in FIGS. 1, 2, and 5 ) of the powered lift truck T illustrated in FIG. 2 , and the respective upright 102 , e.g., attaching to the medial portion thereof. The two braces 122 provide some additional fore and aft reinforcement for the attachments of the lower ends 104 of the uprights 102 to the crossmember C in the embodiment 100 of FIGS. 1, 2, and 5 . It will be seen that the inwardly angled upper ends of the uprights, and braces for the uprights, may be applied to any of the embodiments described herein, but are particularly effective in the load securing device 100 of FIGS. 1, 2, and 5 . [0032] FIGS. 6 and 7 illustrate two additional embodiments of the load securing device for lift trucks. The embodiment 400 of FIG. 6 includes a single upright 402 extending upward from the center of the lateral crossmember C, with the upper end 406 of the upright 402 having a crossmember 407 extending laterally thereacross, essentially parallel to the lower crossmember C. Each end 409 a and 409 b has a tensioner 108 secured thereto. In this manner, the widely spread tensioners 108 have a sufficiently large span therebetween that it is not necessary to set them at an angle other than the vertical. This embodiment may be applied to any of the various lift truck configurations described herein, and/or other lift truck configurations, as practicable. [0033] The load securing device 500 of FIG. 7 includes a single upright 502 extending upward from the center of the lateral crossmember C, with a crossmember 507 extending laterally thereacross, essentially parallel to the lower crossmember C. The crossmember 507 is installed at some point across the upright 502 below the upper end thereof, to form a generally cruciform configuration with the upright. The upright 502 may comprise the mast M of the powered hand truck embodiment 100 illustrated in FIGS. 1 and 2 . Each end 509 a and 509 b of the crossmember 507 has a tensioner 108 secured thereto. In this manner, the widely spread tensioners 108 have a sufficiently large span therebetween that it is not necessary to set them at an angle other than the vertical. This embodiment is particularly applicable to the powered hand truck embodiment 100 of FIGS. 1 and 2 , as noted above, but may be applied to any of the various lift truck configurations described herein, and/or other lift truck configurations, as practicable. [0034] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

The load securing device for lift trucks includes various embodiments adapted for installation upon powered hand trucks, forklifts, and pallet jacks. Each embodiment includes an upright for attachment to the lift truck structure, the upright having a tensioner installed at its upper end or elsewhere opposite the forks of the lift truck. A tensioning element (e.g., tiedown strap, etc.) passes through the tensioner, and a chain and hook extends from the distal end of the tensioning element. The hook of the load securing device is hooked to the load carried on the forks of the lift truck, and the tensioner is tightened to pull and hold the load up adjacent the vertical structure of the lift truck at the back of the forks. Two load securing devices can be used with a powered hand truck for securing a small portable building structure for movement.

The contents of my earlier filed application, filed in West Germany as Ser. No. P3218346.1 on May 14, 1982, is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION In order to satisfy the demand for petroleum and its products, tertiary recovery processes have been developed in which quantities of petroleum remaining in reservoirs after water flooding may be recovered by the use of chemical flooding. For instance, it is known to drive microemulsions through a reservoir with subsequently introduced high viscosity polymeric solutions. In this case, the term "microemulsion" defines a thermodynamically stable emulsion containing oil, water and a surfactant. Such processes are described in U.S. Pat. Nos. 3,506,070 and 3,506,071 which are incorporated herein by reference. It is also known to formulate the microemulsion within the reservoir through injection of an aqueous surfactant solution which then combines with the petroleum and water found within the reservoir. However, these known processes suffer a number of deficiencies. The first mentioned process has the disadvantage that the surfactant used is ionic and generally in admixture with further co-surfactants. In long-lasting underground petroleum recovery, an alteration of the uniformity of the distribution of the surfactants within the microemulsion occurs resulting in a non-homogeneous emulsion which does not function efficiently. Further, the efficiency of this microemulsion also substantially depends on the salt concentration of the water component prevailing in the reservoir. The second process has the disadvantage that the microemulsion is formed within the reservoir only after the injection of the aqueous solution of surfactants. Here too, ionic surfactants are usually used in combination with one or more cosurfactants. Therefore, the resulting variations in the composition and the efficiency of the resultant microemulsion are not unexpected. In particular, variations in the salt content of the water component of the reservoir have a considerable influence with respect to the variations in the efficiency of the emulsion. These recovery methods also suffer from the disadvantage that the microemulsion which is injected into or formed within the reservoir has to be driven through the reservoir by means of a polymer solution. It has been found that extraordinarily large amounts of polymer solution are necessary for this purpose thereby greatly increasing the cost of the process. Finally, it must also be noted that the salinity of the reservoir fluids must fall within a required range. If this salinity is not present within the reservoir, it may be necessary to correct it through injection of water having the desired salt concentration. Recently, there was proposed a process according to which a chemical flooding process can be carried out even if the salt concentration of the reservoir is above the optimal concentration. This process necessitates a graduated salt concentration to be introduced into the reservoir by means of the surfactant and polymer solutions and requires that the reservoir minerals be relatively insensitive to low salt contents. The problem to be solved therefore is to provide an improved process for the emulsion flooding of petroleum reservoirs at an optimum efficiency independent from the salt concentration or its variations within the water phase of the reservoir, without the necessity of using a mixture of surfactants of different chemical composition which might result in an inhomogeneity during production and without the necessity of driving the microemulsion through the reservoir with the aid of a polymer solution. BRIEF SUMMARY OF THE INVENTION According to the present invention the problems of the prior art in the use of surfactant mixtures and polymeric solution during fluids are solved by providing a process for emulsion flooding of petroleum reservoirs, injecting a thermodynamically stable microemulsion consisting of oil, a non-ionic surfactant and water which optionally contains salts dissolved in any desired concentrations into an injection well; and driving the injected microemulsion bank through the reservoir with water which may also contain dissolved salts in any desired concentration. The microemulsion bank/water bank interface forms an excess phase with a high water content, a low surfactant content and low oil content, and has such a viscosity sufficient to prevent the penetration of the water into the microemulsion bank which would cause a decrease of its flowability and its ability to displace oil. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a phase diagram of the three components of the microemulsion, namely non-ionic surfactant, reservoir water and oil. FIG. 2 is a representation of examples for the viscosities of phases in equilibrium in relationship to the shear rate. DETAILED DESCRIPTION OF THE INVENTION This invention relates to a process for emulsion flooding of petroleum reservoirs. More particularly, it relates to a process for the recovery of petroleum from a reservoir having at least one injection well in fluid communication with at least one production well comprising: (a) introducing into the reservoir through the injection well a thermodynamically stable microemulsion comprising oil, water and a non-ionic surfactant; (b) injecting an aqueous driving fluid through the injection well, to drive the microemulsion and petroleum towards the recovery well, the aqueous driving fluid contacting the emulsion thereby forming an excess phase having a high water content, low oil content, a low surfactant content and a viscosity sufficient to prevent penetration of the aqueous driving fluid into the microemulsion; and (c) recovering displaced petroleum from said recovery well. The term "excess phase" defines a phase which is formed at the interface between the injected microemulsion and the subsequently introduced water phase and which contains a high concentration of water and a low concentration of surfactant and oil. The surfactants employed in the present invention are non-ionic polyalkylene glycols which may optionally be substituted. According to a preferred embodiment there can be used a surfactant of the following general formula: ##STR1## wherein R 1 , R 2 and R 3 are the same or different radicals selected from the group of hydrogen and alkyl radicals, comprising 1 to 14 carbon atoms, especially 4 to 10 carbon atoms, m is a numeral of from 2 to 4, preferably 2, and n is a numeral of from 6 to 22. Examples for suitable surfactants which can be used in the process according to the invention are polyethylene glycols, polypropylene glycols and polybutylene glycols which can carry additional substituents, which additional substituents may have a phenolic character, and may comprise also long-chain hydrocarbon radicals. The use of polyethylene glycols is especially preferred. The viscosity of the microemulsion and the excess phase desired for carrying out the process of the present invention is controlled by selection of a specific surfactant in accordance with the physical behavior of the oil to be exploited. The viscosity may be controlled for instance by means of the number of the recurring ether units or the presence of a phenolic substituent in the surfactant. The viscosity of the microemulsion may be up to ten times the viscosity of the oil to be exploited. The viscosity of the excess phase is generally at least two or more times the viscosity of the microemulsion. The microemulsions of this invention are characterized as having water or aqueous solution as the external phase, as essentially Newtonian fluids and as being thermodynamically stable. The oil component of the microemulsion to be injected may consist either of recovered crude oil or of any suitable refined oil component or mixtures thereof. The concentration of the surfactant in the microemulsion can vary within relatively broad ranges. Suitable concentration ranges are from 5 to 20 percent by volume, preferably from 5 to 10 percent by volume, based on the total volume of the microemulsion. The suitable viscosities of the microemulsion and the excess phase formed are determined in relationship to the particular conditions of a reservoir. The desired viscosities can be determined by means of laboratory tests which preferably are carried out with two-phase systems in usual manner. From FIG. 1, it is evident that the three-component system is present in one-phase above the curved boundary line. Furthermore, it can be noted that the phase diagram shows mixture interstices. The conodes recorded in one of the mixture interstices concurrently show thermodynamically stable phases of the microemulsion on the one side and of the excess phase on the other side. From this representation it can be seen that the excess phase, which is indicated in the drawing in the left lower corner, is formed when a microemulsion having a certain composition, such as indicated in the drawing on the right side, is injected and subsequently the microemulsion is contacted with the water phase. In the example represented in the drawing the driving excess phase comprises about 88% water, about 2% surfactant and about 10% oil. It has been found that the excess phase has a suitable viscosity to reliably prevent the water phase which drives the injected microemulsion through the reservoirs from penetrating into the microemulsion. In case such a penetration of the water phase into the microemulsion would occur, the homogeneity of the microemulsion would be destroyed rendering the microemulsion incapable of driving out the trapped oil. Moreover, the movement of the microemulsion through the reservoir would be endangered. Driving the microemulsion reliably through the reservoir without the occurrence of disturbances by penetrating water can be accomplished during recovery as long as the microemulsion is in equilibrium with the excess phase. The advantage achieved according to the present invention resides in the fact that it is no longer necessary to use a polymer solution for driving the microemulsion through the reservoir. Furthermore it can be taken from FIG. 1 that it is possible to use a single surfactant, without the co-use of co-surfactants, in the presence of high salt concentration reservoir fluids. A further advantage of the process according to the present invention resides in the fact that there can be obtained optimal viscosities of the microemulsion and the excess phase as well as the presence of a three-phase area, as represented in FIG. 1 by the hatched lower area. The phases present in this hatched area are formed at the front surface of the injected microemulsion which comes into contact with water and oil contained in the reservoir. In this hatched area so-called middle-phase microemulsions are in equilibrium with the excess phases of oil and water. According to their nature, they possess low interfacial tensions towards the excess phase. They are capable of displacing not only the oil from the reservoirs but also the water. These middle-phase microemulsions are automatically formed at the front surface of the injected microemulsion being in contact with water and oil, and thus protect the main part of the microemulsion from the contact with oil and water of the reservoir. The advantage achieved thereby is that the process of the present invention can be carried out independent of the variations of the salt concentration of the reservoir water, which, it is known, may occur during the recovery of petroleum from a reservoir. FIG. 2 shows a further example demonstrating the viscosity behavior of the phases in equilibrium in the two-phase area of concern. It can be seen from the viscosity that the microemulsion is a Newtonian fluid as its viscosity does not depend on the shear rate, whereas the excess phases have viscosities which vary inversely to the shear rate. This viscosity behavior of the excess phase is similar to the viscosity behavior of the polymer solutions which had to be applied in hitherto known processes using ionic surfactants and co-surfactants. Therefore, it appears that the excess phases may adequately assume the functions previously performed by the polymer solutions. Apart from the advantage that the use of an additional polymer solution is no longer necessary, the instant invention also possesses the advantage that the excess phase is formed exactly at the place at which it is needed, so that any undesired dispersion of the driving media with respect to the microemulsions is reliably prevented. A further advantage of the invention resides in the fact that only a relatively small amount of the microemulsion is necessary. Suitable amounts are within the range of 5 to 30%, preferably 5 to 15%, based on the total pore volume of the reservoir minerals. The invention is explained in detail by means of the following Example. EXAMPLE A microemulsion of 7% by volume dinonylphenoloxethylate with an average of 11 recurring ethylene oxide units as a non-ionic surfactant (53% by volume of a mixture of a refined oil and the reservoir oil to 40% by volume brine, having the composition indicated below) possessing a viscosity of 29.4 cp was produced. The brine had the following composition: ______________________________________ g/l______________________________________ NaCl 112.3 KCl 4.2 CaCl.sub.2 11.1 MgCl.sub.2 5.5______________________________________ This microemulsion was injected in a linear laboratory model of a reservoir which had been subjected to water flooding. The microemulsion formed an excess phase with the following composition: 0.4% by volume dinonylphenoloxethylate (11 moles ethylene oxide units) 3.3% by volume of the aforementioned oil mixture, and 96.3% by volume of the brine used in the microemulsion. This excess phase had a viscosity of 78 cp under these test conditions. There was obtained an oil displacement of 100% of the remaining oil when injecting the microemulsion in an amount of 15% of the pore volumes being present in the linear laboratory model of the reservoir.

A process for emulsion flooding of petroleum reservoirs comprising injecting a thermodynamically stable microemulsion consisting of oil, a non-ionic surfactant and water which optionally contains salts dissolved in any desired concentrations, into an injection well; driving injected microemulsion bank through the reservoir by means of water which likewise may contain salts dissolved in any desired concentrations. The microemulsion bank in contact with the water driving the bank forms an excess phase with a high water content, a low surfactant content and low oil content, and has such a viscosity sufficient to prevent the penetration of the subsequent water into the microemulsion bank which would cause a decrease of its flowability and its ability to displace oil.

BACKGROUND AND SUMMARY OF THE INVENTION Perishable liquids, such as milk and other foods, are typically stored in large tanks. These tanks are provided with heat exchange surfaces in the interior or in the lower portions of the walls of the tanks. The liquid, e.g., milk, is added to the tank and cooled by exposure to the heat exchange to a temperature below that at which significant decomposition and bacterial action takes place. In the case of milk, it is typically stored at a temperature range between slightly above freezing, about 33° F., to below about 40° F. A mean temperature of 37° F. would be typical. Bulk storage and cooling tanks for milk are found commonly on large dairy farms where the milk is produced. The milk is collected by a bulk truck from the tanks, usually every other day. This means that the tank must be sufficiently large to store and cool 2 days' milk production or the milk produced in four milkings. This creates a number of problems since the milk stored in the tank previously will be at a stable temperature below 40° F. and the milk introduced into the tank in subsequent milkings will be introduced at a temperature near 98° F., the body temperature of the cow. Usually there is some temperature drop in the inlet line so the milk would enter the tank at approximately 90° F. It has been claimed that the quality and shelf life of fluid milk is improved when the incoming milk is cooled before mixing with the milk already in the tank. In an effort to gain this quality and shelf life improvement, some regulatory agencies have required that some form of precooling equipment be used to cool the milk prior to introducing it into the tank of previously cooled milk. These pre-coolers typically take the form of tubular or plate type heat exchangers, placed upstream of the bulk tank. The precoolers lower the temperature of the milk to below 40°F. prior to introducing it into the tank. Due to the periodic nature of milking, the heat exchange capacity of these devices must be quite high during the short time in which they are used; they remain unused for the major portion of the day. To level out the heat duty on the pre-coolers, they are normally used in conjunction with refrigeration equipment such as water chillers or ice makers which can supply heat exchange capacity by acting as a heat sink during the period of demand upon the equipment. All of this heat exchange equipment, however, takes up considerable valuable space, is costly to purchase and to maintain, is difficult to clean and keep in sanitary condition and may create excess pressure drop and shear which damages the milk. Applicant has invented a device which eliminates the necessity for pre-coolers stationed in line upstream of bulk milk storage tanks and tanks for storing other perishable liquids. The device reduces the temperature of incoming liquid prior to mixing with the stored mass. The equipment is contained within the tank, easily cleaned, small, inexpensive to purchase and operate, has a very low maintenance, and has very efficient heat transfer. The device rapidly cools the incoming liquid without subjecting it to severe mechanical action which, in the case of milk particularly, may damage it or reduce its quality. Applicant has devised a method of rapidly cooling perishable liquids on introduction into bulk storage without mixing the incoming warm liquid with the bulk of the cooled liquid in the storage tank. The temperature of the liquid introduced into the tank is rapidly reduced to a stable temperature and the temperature of the mass of liquid stored in the tank never gets above a stable temperature locally and in the mass. In particular for milk, the temperature of milk stored from previous milkings in bulk storage is maintained below 40°F. even when fresh milk is added at each additional milking. Applicant's device and method use a horizontally disposed spinning disc located at the top of a bulk storage tank to distribute liquid in a film over the surfaces of the tank walls and ends. The heat exchange in the tank is placed in the walls and ends of the tank, not only in the lower portions of the tank, but throughout the walls and ends up to the top of the tank. The liquid is introduced on the rotating disc which propels the liquid in a thin stream off the periphery of the disc onto the upper portions of the tank walls and ends. The liquid flows down the walls and ends in a thin film over the heat exchange surfaces. The thin film provides a very efficient transfer of heat from the liquid into the heat exchange medium and effects an extremely rapid cooling of the liquid as it flows down the walls. The liquid stored in the tank is maintained by the heat exchange in the lower portion of the tank at a stable temperature. As the tank fills up with each addition of new liquid, the cooling of the liquid on the heat exchange surfaces in the upper portions of the tank is sufficient, when combined with the sensible heat of the stored liquid, to insure that the temperature of the mass of liquid stored in the tank never rises above a stable temperature. DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a bulk milk storage tank incorporating the device of the invention; FIG. 2 is an end view of the tank of FIG. 1; FIG. 3 is a partial sectional view of the milk tank of FIG. 1, showing the disc distributor device; FIG. 4 is an isometric view in partial section of the disc in FIG. 3; FIG. 5 is an isometric view in partial section of an alternative disc; FIG. 6 is a top view of the manhole cover for mounting the disc; FIG. 7 is a partial sectional view of the manhole cover and tank showing the alternative disc and an alternative milk inlet; FIG. 8 is an alternative drive mechanism for rotating the disc; and FIG. 9 is a chart showing the temperature of milk stored in a 3,000 gallon bulk milk storage tank during addition of milk from four separate milkings. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring in more detail to the drawings, particularly FIG. 1, a bulk liquid storage tank 20 is shown having side walls 22 and ends 24 incorporating heat exchange surfaces 25. An agitation mechanism shown at 26 may be included in the tank to improve heat transfer. The tank 20 has a central manhole 27 in which the milk distribution apparatus 28 is located. The milk distribution apparatus 28, shown in more detail in FIG. 3, consists of a manhole cover 30 having a gasket 32 which fits over the manhole 27 and forms a tight sanitary seal. A liquid inlet line 34 is attached to a balance tank or surge tank 36. The line 38 from the balance tank 36 passes through a seal 40 in an orifice 42 in the manhole cover 30 and terminates at a pipe 44 in the interior of the tank 20. The pipe 44 terminates just above a horizontal disc 46. Relief line 47 joins the upper portion of tank 36 and line 38. The disc 46 is attached to a vertical shaft 48, which passes upwardly through a rubber seal 50 in an orifice 52 in the manhole cover 30. The shaft 48 is rotated by a gear reducer 54 and electric motor 56. If desired, an insulating coupling 57, may be provided between shaft 48 and gear reducer 54 to thermally insolate the disc 46 from the heat generated by gear reducer 54, since the heat may increase the temperature of the milk. Concentric to the shaft 48 is a circular well 58 which is recessed in the upper surface 59 of the disc 46. The well 58 surrounds the inlet pipe 44. The well 58 has a rounded shoulder 60 which allows the liquid to flow evenly onto the upper surface 59 of disc 46. The periphery of the disc 46 may have a knife edge or taper at 64 (shown in FIG. 4) which helps the liquid to flow evenly off the periphery of the rotating disc without atomization and helps maintain a stream of liquid flowing toward the walls of the tank. FIG. 5 shows an alternative embodiment of the disc 46 utilizing a vertical wall 66 in the center of the disc, instead of the well 58, to distribute the liquid onto the upper surface of the disc 46 via slot 67. Slot 67 is formed by spacing vertical wall 66 from the surface 59 of the disc 46 with welded pads 68. The slot 67 is preferably between about 1 to 3 millimeters in height. A third alternative, not shown, is to place the inlet pipe 44 at a location to supply the liquid onto the rotating shaft 48 at a location spaced above the upper surface of the disc 46. The liquid spirals down the shaft 48 during rotation and is evenly distributed on the upper surface of the disc 46. This embodiment is somewhat more difficult to adjust and maintain, but it does provide effective distribution of the liquid onto the disc 46. FIG. 8 shows an alternative drive mechanism, for rotating the disc 46 via the shaft 48. In the alternative drive mechansim an electric motor 69 drives a sheave 70 and through a belt 72 drives a sheave 74. The sheave 74 is attached to a rotating quill 75 mounted on a pair of spaced bearings 76. The rotating quill 75 drives the shaft 48 extending through the rubber seal 50 in the orifice 52 in the manhole cover 30. The manhole cover 30 is mounted to the top of the tank 20 by a pair of spaced lugs 78 having holes 80 which cooperate with corresponding lugs 81, and holes 82 on the upper surface of the tank 20 to receive hinge pin 83. The cover 30 may be pivoted into and out of a covering relationship with the manhole 27. The disc 46 and disc drive mechanism is mounted to the manhole cover 30 and pivots into and out of the manhole 27 when the cover 30 is pivoted into and out of a covering relationship with the manhole 27. A set of mounts 84 on the cover 30 receive a set of mounting bolts 86 which extend through mounting plate 88 of gear reducer 54 and motor 56 or through the motor-quill housing 90, 92. A strap 94 holds the manhole cover 30 in a closed position when the distributor 28 is in operation. The disc 46 is normally placed in the upper part of the tank 20 at a location between 1 to 11/2 inches of the top of the tank. The disc 46 is sufficiently large that it will carry a significant volume of liquid in a thin film distributed about its upper surface. Typically the disc 46 will be from 15 to 20 inches in diameter. The well 58 or the dam 66 will be of sufficient size to hold a substantial volume of liquid for distributing on the upper surface of disc 46. Typically the well 58 and the dam 66 will be from 3 to 6 inches in diameter and from 1 to 3 inches in heighth or depth. The dam 66, if used, will be tapered slightly inwardly at the top to resist the tendency of the liquid to climb the walls of the dam during rotation of the disc. The slit 67 will be sufficiently large that the volume of milk will flow outwardly under the influence of the head of milk held in the dam 66, but is sufficiently small to effectively distribute the milk evenly over the upper surface of the disc 46. Typically the slit 67 will be from 1 to 3 millimeters in height. In operation of the bulk milk cooler during milking, as shown in the drawings, milk is received from the milking line 34 shown into the balance tank 36 to smooth out the surges and supply inertia to the system. The milk then flows relatively evenly out of the balance tank 36 through the pipe 38 and into the bulk milk tank 20 and out the outlet pipe 44 onto the rotating disc 46. The disc 46 is driven at a rotational speed of between about 300-550 rpm, depending on the tank and disc size, by the shaft 48 attached to the gear reducer 54 and the motor 56 or the sheave 74. The outlet pipe 44 terminates inside the well 58 so that a pool of liquid is built up in the interior of the well 58 and passes outwardly over rounded shoulder 60 to form a thin film on the upper surface of the rotating disc 46. The thin film passes outwardly under the influence of the centrifugal force generated by the rotating disc 46 and flows off the knife-edge periphery 64 of the disc. The knife edge aids in expelling the liquid from the periphery of the disc 46 as a stream of liquid so that it is not atomized. Atomization should be carefully avoided since it tends to entrain air into the liquid. Entrained air is a disadvantage in cooling milk since oxygen in the air tends to react with the butterfat in the milk and produce rancidity. It the disc shown in FIG. 5 is used, milk is introduced from the outlet pipe 44 into the interior of concentric dam 66 in the center of the spinning disc 46 and under influence of the rotation of the disc, flows outwardly underneath the dam 66 through the slot 67 onto the upper surface of the disc 46 and forms a smooth even film over the surface of the disc which is expelled from the periphery 64 to the walls of the tank 20. The liquid or milk is propelled from the disc 46, follows a normal trajectory in a generally horizontal direction to the walls and ends 22, 24 of the tank 20 and flows down the interior surfaces of the bulk tank which contain heat exchange 25, shown in FIGS. 1 and 2 as being in four separate zones A, B, C and D, and flows down the walls in a thin film, subject to the influence of the heat exchange. The heat exchange zones, A, B, C and D, extend substantially to the top of the tank, as shown in FIGS. 1 and 2, so that the liquid is under the influence of heat exchange 25 at all levels of the tank. FIG. 9 shows the graphical results of an acutal test performed with a 3,000 gallon tank equipped with four zones of heat exchange and with the liquid distributor of the invention. The test was conducted through four cycles over a period of 2 days. Water, simulating milk, was introduced into the tank at 90°F. and reduced to a temperature below 40°F. and held at that temperature for up to 2 days. As shown by curve E at the far left side of FIG. 10, the temperature of the liquid introduced into the bulk tank dropped rapidly to 38°F. as a result of the heat exchanged in flowing over the surfaces of the zones A, B, C and D of the walls 22, 24 of the tank 20. This temperature was held throughout a cycle of 21/2 hours (150 minutes), a normal milking cycle, and a total of 750 gallons of liquid was added during the first cycle. pg,11 As shown by curve F, by the beginning of the second cycle, 12 hours after the start of the first cycle, the temperature of the liquid in storage was cooled down to 37°F. At the beginning of the second cycle, liquid was again introduced into the tank and distributed over the cooling surfaces. The liquid temperature in the tank began to rise as a result of the addition of the liquid during the second period, but never rose above 39°F. by the end of the second cycle. At the end of the second cycle a total of 1,500 gallons of liquid was present in the tank. As shown by curve G, the temperature of the liquid in the tank was reduced to 37°F. by the beginning of the third cycle, 12 hours later. Liquid was again introduced into the tank and cooled by flowing over the heat exchange surfaces of the tank. The temperature of the bulk of liquid in the tank rose during the third cycle from 37°F to 391/2°F. by the end of the third cycle. At the end of the third cycle, a total of 2,250 gallons of liquid was in the tank. As shown by curve H, the temperature of liquid in the tank was again reduced to 37°F. by the beginning of the fourth cycle, 12 hours later. Liquid was again introduced into the tank and the temperature rose to 39°F. at the end of the cycle, at which time 3,000 gallons of liquid had been stored in the tank without ever having been heated to a temperature of above 40°F. As shown by the tests illustrated in FIG. 9, applicant's cooling device and method is able to effectively cool large volumes of perishable liquids and blend warm fresh liquid into stored liquid without raising the temperature of the mass of liquid to an unstable or unsafe level. Applicant's device accomplishes this result without expensive and bulky pre-coolers and in a compact and easily cleaned structure. It will be appreciated by one skilled in the art that various changes or modifications may be made in addition to those described herein without departing from the scope of the claimed invention. It is intended that all matter described in the foregoing specification shall be interpreted as being for purposes of illustration and not as limiting the invention claimed.

A bulk tank cooling and storage apparatus has heat exchange surfaces substantially covering the side and end walls of the tank. The tank is supplied with a horizontal rotating disc liquid distributor which uniformly distributes the liquid in a sheet over the heat exchange surfaces so that it flows downwardly over the surfaces in a thin film and is cooled by heat exchange operating in cooperation with the heat exchange surfaces. Even distribution of the liquid is provided by the rotating disc distributor which expels liquid from the periphery of the rotating disc and propels the liquid against the walls of the tank. Liquid fed into the tank is directed to the center of the rotating disc where a cylindrical dam or well holds a reservoir of the liquid and distributes it on the surface of the disc. The periphery of the disc may have a knife edge which helps the film of liquid to flow off smoothly without atomization.

TECHNICAL FIELD The present invention relates to a device for the automatic coupling of a blowing-in lance to a manifold which is in communication with ducts conveying fluids intended to be injected into a molten metal bath through channels running through the lance. BACKGROUND OF THE INVENTION The subject of the present invention is, particularly, lances used for the conversion of cast iron into steel and which are dipped into the converter in order to inject the refining substances into the metal bath. For this purpose, these lances comprise a series of channels, generally concentric, for blowing in these substances and for cooling the lance. U.S. Pat. No. 3,972,515 the disclosure of which is incorporated herein by reference, proposes a device for coupling such a lance leaktightly to a manifold which is in communication with the ducts supplying the lance with refining substances and with cooling liquid. The contact surfaces between the lance and the manifold must, of course, be designed as a leaktight surface in order to prevent any leakage of these gaseous and liquid substances, while the clamping between the manifold and the lance must be sufficiently powerful to preserve this leaktightness. In the device known from the abovementioned document, the mounting of the lance on the manifold is effected manually with the aid of clamping bolts. In the device proposed in the document DE-Al-3,828,928, the mounting of the lance on the manifold is effected automatically via pivoting hooks actuated by hydraulic jacks. In both of the two devices, the mounting between the lance and the manifold must not only ensure leaktightness at the joining surfaces, but also the support of the lance, given that the latter is carried by the manifold. If follows that a very rigid mounting is necessarily required between the lance and the manifold with the consequence that the manifold, the joint and the ducts are obligatorily exposed to the vibrations of the lance. SUMMARY OF THE INVENTION The object of the present invention is to provide an improved device of the above-described type, in which the coupling of the lance to the manifold is also effected automatically but in which, in contrast to the known devices, the contact and joining surfaces between the manifold and the lance are not exposed to the vibrations, or even the impacts which the lance is subjected to during its operation and its handling. In order to achieve this objective, the automatic coupling device proposed by the present invention is essentially characterized by means for hitching the lance rigidly to the lance-carrying carriage, and by means ensuring the support of the manifold with respect to the lance-carrying carriage and enabling the manifold to be displaced vertically with respect to the lance-carrying carriage, or vice versa. According to a first embodiment, the manifold is mounted to a manifold-carrying carriage which can either be made integral, via the manifold and the lance, with the lance-carrying carriage, or be immobilized, by gravity, with respect to the slide rail of the latter. According to this first embodiment, the manifold can be mounted via resilient means on the manifold-carrying carriage. To this end, it can comprise a peripheral flange by means of which it is supported between three pairs of vertical springs fixed on a plate integral with the manifold-carrying carriage. The lance-carrying carriage can be displaced via guide rollers with respect to the manifold-carrying carriage when the latter is immobilized with respect to the slide rail. This immobilization can be effected by a catch which can be displaced under the action of a jack in order to support the lance-carrying carriage with respect to the slide rail. According to an alternative of this embodiment, the manifold-carrying carriage is supported by at least one jack mounted on the lance-carrying carriage in order to displace the manifold-carrying carriage when the lance is changed. According to another embodiment, the manifold slides directly, without an intermediate manifold-carrying means, on the lance-carrying carriage and can be supported with respect to the latter either by a moveable catch or by a jack, as in the first embodiment. In contrast to the known devices in which the lance is hitched rigidly to the manifold, the device proposed by the present invention provides for the lance to be hitched rigidly to the lance-carrying carriage and for the manifold to be supported via the lance-carrying carriage. The vibrations and impact to which the lance is exposed are therefore transmitted to the lance-carrying carriage. On the other hand, by virtue of its non-rigid suspension, the manifold can, when it is integral with the lance head, adapt to the vibrations of the latter without affecting the leaktightness in the region of its joint. with the lance. With a view to the mounting of the lance on the manifold, the latter can comprise two hooks which pivot under the action of hydraulic jacks via connecting links which are eccentric with respect to the axis of the hooks. With a view to the hitching of the lance to the lance-carrying carriage, the lance can comprise two pairs of journals, while the carriage comprises two pairs of supports, each equipped with notches for receiving and carrying the journals of the lance, while each of the notches is associated with a hook actuated by a jack in order to lock the journals in the notches and to connect the lance rigidly to the lance-carrying carriage. BRIEF DESCRIPTION OF THE DRAWINGS: Other features and characteristics will emerge from the detailed description of some advantageous embodiments given below, by way of illustration, with reference to the drawings in which: FIGS. 1 to 5 show, in lateral diagrammatic views, a first embodiment with the various sequences of hitching a lance to a manifold. FIG. 6 shows an alternative of the embodiment of FIGS. 1-5. FIG. 7 shows a view, from above, of a second embodiment. DETAILED DESCRIPTION OF THE INVENTION The figures show a lance-carrying carriage 8 designed in order to be displaced vertically, e.g. by means of guide rollers 12 along a slide rail or running track 10, e.g. with the aid of cables or chains running around pulleys 14 in order to dip a lance 16, hitched to the carriage 8, into a converter (not shown) and in order to extract it therefrom. With a view to the hitching of a lance 16 to the carriage 8, the latter comprises a pair of upper supports 18 and a pair of lower supports 20. In the figures, one of the supports of each pair is hidden by that which can be seen in the figures. The two supports of each pair are sufficiently spaced apart horizontally from each other to enable the lance 16, transported with the aid of a hook 22, to be engaged between them. The two supports 18, 20 are provided with notches 30, 32 corresponding to a pair of upper journals 28 and a pair of lower journals 26 Provided on the lance 16 and by way of which the latter is placed in the notches 30, 32 by means of the hook 22, another pair of journals 24 serving for hitching the lance 16 to the hook 22. Each of the notches 30, 32 is associated with one or more, preferably two, pairs of upper and lower hooks 34, 36 (only one of the hooks of each of the pairs being visible in the figures) in order to ensure the mounting of the lance 16 in the notches 30, 32 and the rigid connection between the lance 16 and the carriage 8. Each pair of hooks 34, 36 is actuated by one or, preferably, by a pair of jacks 38, 40. The hooks 34 and 36 are mounted as in the document DE-Al 3,828,928 on spindles which are eccentric so as to effect, in a manner known per se, a composite pivoting and translational movement. Under the action of the jack or jacks 38, the hooks 34 pivot about their spindle, followed by a slight lowering movement of their spindle in order to lock the journals 28 in the notches 30. The hooks 36, on the other hand, effect, under the action of the jack or jacks 40, by virtue of their eccentric mounting, essentially a horizontal translational movement of small amplitude in order to jam the journals 26 in the notches 32 or to free them therefrom. The reference 42 designates a manifold which is in communication with the ducts 44 which transport the refining substances, and with the cooling ducts 46. The way in which these ducts are connected to the manifold 42 and traverse the latter is shown in more detail in the two abovementioned documents illustrating the prior art. According to one of the features of the first embodiment, the manifold 42 is mounted via resilient means on a manifold-carrying carriage 48 which can slide vertically with respect to the lance-carrying carriage 8 and vice versa, via running rollers 50. The manifold 42 comprises a peripheral flange 52 by way of which it is carried between a group of a plurality of upper helical springs 54 and a group of lower helical springs 56, some of these upper and lower springs being hidden in the figure. Each of these upper and lower springs 54 and 56 are attached via a coaxial rod to a plate 60 which is integral with the manifold-carrying carriage 48. The manifold 42 consequently has a certain freedom of movement between the upper springs 54 and the lower springs 56. Although the mounting of the manifold 42 via springs on its carriage 48 provides the advantage of greater flexibility, it should be noted that his resilient mounting is not essential since the fact that the lance 16 is no longer carried by the manifold 42, but by its carriage 8, already makes it possible to achieve the desired object. The proposed device furthermore comprise means for immobilizing the manifold-carrying carriage 48 with respect to the slide rail 10, the lance-carrying carriage 8 remaining, however, free to slide vertically with respect to the manifold-carrying carriage 48 and the slide rail 10. In the example shown, these means consist of a catch 62 which can be displaced horizontally under the action of a jack 64. When the jack 64 is extended, as shown in FIG. 1, the catch 62 penetrates beneath the carriage 48 and forms a stop supporting the carriage and the manifold 42. Instead of providing a sliding catch, it is also possible to provide a pivoting catch. The various sequences of coupling a lance 16 to the manifold 42 will now be described with reference to FIGS. 1 to 5. A lance 16 is brought into position by the hook 22 and is placed by way of the journals 28 and 26 in the notches 30 and 32. The hook 22 can be lowered until the lance 16 is carried by the journals 28 and 26 in the notches 30, 32, after which the hook 22 can be removed (see FIG. 2). Then, the jacks 38 and 40 are actuated in order to jam the journals 28 and 26 of the lance 16 in the notches 30 and 32 (see FIG. 3) and to make the lance 16 completely integral with the carriage 8. The next step, shown in FIG. 4, consists in effecting the coupling between the manifold 42 and the joint face 70 of the lance 16. For this purpose, the manifold 42 comprises a pair of hooks 66 which are actuated under the effect of eccentrically pivoting connecting rods when the pate 67 is displaced by hydraulic jacks 69. These hooks 66 are comparable with the hooks 34, in other words they are mounted on a spindle which, when it pivots, effects a slight translational motion in the vertical direction by virtue of the connecting links which are eccentric with respect to the spindle of the hooks. With a view to the coupling, the lance-carrying carriage 8 is raised into the position in FIG. 4 until the joint face 70 of the lance 16 is in contact with the lower face of the manifold 42, or in immediate proximity to this face which, for this purpose, can comprise a socket for receiving the lance 16 with the appropriate seals. Then, the jacks 68 are actuated in order to close the hooks 66 and to hitch on the journals 24, as shown in FIG. 5. The manifold 42 is from then on entirely integral with the lance 16 and, consequently, with the lance-carrying carriage 8. The next operation consists of actuating the jack 64 and retracting the rod of the latter in order to release the catch 62 from the manifold-carrying carriage 48 (FIG. 5) and to free the latter with respect to the slide rail 10. The carriage 48 is then supported by the lance-carrying carriage 8 via the springs 54, 56, the manifold 42 and the lance 16. All that needs to be done then in order to dip the lance 16 into the converter is to lower the assembly formed by the two carriages 8 and 48 along the slide rail 10. The disassembly of a lance 16 follows, of course, the same procedure in reverse, in other words initially raising the carriage 8 in order to remove the lance 16 from the converter, maneuvering the jack 64 in order to fasten the manifold-carrying carriage 48, opening the hooks 66, lowering the lance-carrying carriage 8, opening the hooks 34 and 36 and detaching the lance 16 via the hook 22. FIG. 6 shows an alternative of the above embodiment which makes it possible to dispense with the catch 62 and its jack 64. According to this alternative, the manifold-carrying carriage 48 is supported by a jack 74 or two jacks 74 which is or are integral with the lance-carrying carriage 8. When a lance is changed, the lance-carrying carriage 8, with the lance 16, remains stationary, while the manifold-carrying carriage 48 is displaced under the action of the jack 74 in order to effect the approaching or releasing maneuvers between the manifold and the lance, in contrast to the embodiment according to FIGS. 1 to 5 in which the lance-carrying carriage 8 is displaced, while the manifold-carrying carriage 48 remains stationary. The advantage of this alternative is that the winch and the pulleys 14 do not need to be actuated when a lance is changed. FIG. 7 shows a top view of a second embodiment. The reference 8 designates a lance-carrying carriage with its rollers 12 identical to those of the first embodiment. The reference 76 designates the manifold with its connection pipes 78. In contrast to the first embodiment, the manifold 76 is no longer supported by a carriage but is equipped directly with running rollers 80 and with guide rollers 82 which move along in corresponding vertical rails 84 of the lance-carrying carriage 8 and enable the manifold 76 to slide vertically with respect to the carriage 8. The vertical support of the manifold 76 can be affected either, following the example of FIGS. 1 to 5, by means of the lance 16 and a catch 62 (not shown), or, according to FIG. 6, with the aid of a jack (not shown). The advantage of the embodiment in FIG. 7 is a more simple, more compact and more robust construction. While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitations.

A device for automatically coupling a lance for injecting a fluid into a molten metal bath to a manifold for supplying the fluid to the lance includes means for hitching the lance rigidly to a lance-carrying carriage which can be displaced along a slide rail, and means ensuring the support of the manifold with respect to the lance-carrying carriage and enabling the manifold to be displaced vertically with respect to the lance-carrying carriage, or vice versa.

FIELD OF THE INVENTION The present invention in general relates to an improved well head system and in particular to an improved mechanism for locking a valve stack atop a well head, on beam members of the well template. The valve stack may be a Blow Out Preventer (BOP) and according to the invention, by virtue of this locking, the effect of bending moment on well head by the BOP and a riser connected to the BOP is substantially prevented. Particularly, the present invention relates to a well head system according to the preamble of claim 1 and to a locking device according to the preamble of claim 7 . TECHNICAL BACKGROUND OF THE INVENTION Well head systems for sub sea exploration are traditionally known to comprise a well head having a well head housing secured to a well casing. It also comprises a valve stack, such as a Blow Out Preventer (hereinafter referred to as BOP), located atop a well head during drilling, work-over operations and some phases of the production. Especially, during drilling operations, the drill bit often penetrates pockets of pressurized formations. Due to this, the well bore experiences rapid increase in pressure and unless prevented may result in disastrous blow outs. Hence locating BOPs atop well heads is now very common and indispensable in sub sea exploration. Now, tubular members such as risers are connected on the top of the well head housing along the through bore of a BOP. The well head housing is in turn secured to the well head casing by welding. When a riser is connected and operated on the top of the well head housing, it creates a very high bending moment on the connecting surface of the lower part of the well head housing and the upper part of the casing, i.e. at the welded joint area. As a result, the well head and casing experiences strain causing substantial fatigue and may eventually initiate cracks on the well head, thereby expediting its deterioration. In a sub-sea drilling operation the connection of the well head housing and well head casing has to endure stress for 5000 days of the BOP and riser being connected, e.g. during work-over operation and this fairly indicates the amount of strain the well head has to withstand due to bending moment generated during riser operation with a safety factor of 10. Now to ensure that the well head does not undergo fatigue and tear by bending moment generated during riser operation, it is essential that the BOP should be firmly locked so that less moment is transferred to the weld zone between the well head housing and the casing. This is also essential to ensure that there is no risk of blow out by virtue of a break in the weld between the well head housing and the casing. Attempts are on over the years to appropriately secure BOPs on well heads to prevent well blow outs, but in prior art technology the approach to ensure firm locking of the BOP on the well head components, with a motive to substantially prevent the effect of bending moment on the lower part of the well head housing and the upper part of the casing during operation of tubular members such as risers, along BOP, is missing. To be precise, the prior art does not teach locking of a BOP firmly on the well head components, such as the well template, to prevent the well head from movement due to bending moment generated during riser operation, so that fatigue of the well head is substantially reduced during riser operation. Hence, the issue of withstanding heavy bending moment on the welded area of the housing-casing joint during riser operation and fatigue of the welded joint area still remains unresolved. This consequently, leaves the problem of minimising/nullifying fatigue of the well head and a potential risk for cracks in the joint area, unresolved. The worst eventuality of this can of course be that the well head disconnects from the casing and results in an uncontrollable blow-out. Accordingly there was a long felt need for a locking technology for locking valve stacks, such as BOPs atop a well head on the well template, so that the effect of bending moment on the well head is substantially reduced. The present invention meets this long felt need by locking the BOP on beam members of the well template, by providing specially configured locking devices suitably located on axially movable vertical telescopic arms, the arms being positioned along the vertical supporting columns of the BOP. OBJECTS OF THE INVENTION The primary object of the present invention is to provide a well head system which is capable of substantially reducing the effect of bending moment/stress experienced on its welded joint area during riser operation. It is yet another object of the invention to provide a BOP atop a well head, which is equipped with a specially configured locking mechanism to substantially prevent the well head from movement due to bending during riser operation through the BOP. It is a further object of the present invention to provide a locking mechanism having a plurality of locking devices for locking a BOP on beam members of the well template, so that the effect of high bending moment on the lower part of the well head housing and the upper part of casing is substantially reduced. It is a further object of the present invention to minimise/nullify fatigue of the well head and the potential risk for cracks in the well head housing—well casing joint area, during riser operation. It is a further object of the present invention to reduce the risk of blow out during riser operation. It is yet a further object of the invention to provide a well head system which conforms to the regulatory criteria and safety standard in well drilling processes. All through the specification including the claims, the words “BOP”, “riser”, “spindle”, “columns”, “frame”, “beam member”, “clamping arms”, “winching device”, “ROV”, “well template” are to be interpreted in the broadest sense of the respective terms and includes all similar items in the field known by other terms, as may be clear to persons skilled in the art. Restriction/limitation, if any, referred to in the specification, is solely by way of example and understanding the present invention. Furthermore, the description and claim refers to operation of risers and it is hereby clarified that the present invention is equally applicable in respect of operation of other members operated atop sub sea well heads, as will be clear to persons skilled in the art. SUMMARY OF THE INVENTION According to a first aspect of the present invention there is provided a well head system for application in sub sea well exploration. It comprises a well head having a well head housing secured to a well casing and at least one valve stack, e.g. a BOP located atop the well head. According to the invention, the valve stack is removably locked on a well template supporting the well head, by a plurality of locking devices. According to a preferred embodiment of the first aspect of the present invention each locking device comprises a spindle fixedly attached to a telescopic arm. It is adapted to axially move downward and upward with corresponding axial movement of the telescopic arms for locking and unlocking respectively. Preferably, two opposite clamping arms are adapted to grip a beam of the well template. More preferably, the lock comprises a securing mechanism acting to lock a main frame carrying the clamping arms to a spindle. According to a second aspect of the present invention there is provided a locking device for securing a valve stack atop a well head having a well head housing secured to a well casing. According to the invention, the locking device is adapted to releasably lock the valve stack to a well template supporting the well head. BRIEF DESCRIPTION OF THE DRAWINGS Having described the main features of the invention above, a more detailed and non-limiting description of some exemplary embodiments will be given in the following with reference to the drawings, in which FIG. 1 is a perspective view of a BOP according to a preferred embodiment of the present invention. FIG. 2 is an illustrative view of the telescopic arm of the BOP having a winch device according to a preferred embodiment of the present invention. FIG. 3 is a front view of the telescopic arm shown in FIG. 2 . FIG. 4 is a sectional view of the telescopic arm shown in FIG. 3 along the line A-A. FIG. 5 is a perspective view of the BOP according to the present invention in operation showing the well head components, including a well template, the well head and the location of the locking apparatus. FIG. 6 is a perspective view of a preferred embodiment of the locking apparatus according to the present invention in locked position. FIG. 7 is an axial cut section along the vertical axis of the device illustrated in FIG. 6 for the sake of understanding. FIGS. 8 to 10 coherently illustrate the different positions of the locking apparatus during operation. DETAILED DESCRIPTION OF THE INVENTION The following describes a preferred embodiment of the invention which is exemplary for the sake of understanding the present invention and non-limiting. The main aim of the present invention, as stated before, is to substantially reduce the bending moment during riser operation on the lower part of the well head housing (not shown in FIG. 1 ) and the upper part of the casing (not shown in FIG. 1 ), where the welding joint between the two is located. This is achieved primarily by firmly locking the BOP on the well template by specially configured locking devices, at several points along the supporting beams of the well template during riser operations, as hereinafter explained with reference to the drawings. This in turn facilitates reducing the effect of bending moment on the well head during riser operation, thereby increasing its longevity. By reducing the effect of such bending moment, fatigue of the well head and the potential risk for cracks in the well head housing—well casing joint area during riser operation, is substantially minimised/nullified. This in turn also reduces the possibility of most unprecedented eventuality of disconnection of the well head from the casing, resulting in an uncontrollable blow-out. FIG. 1 illustrates a BOP assembly 1 including a Christmas tree 6 and room for a BOP stack (not shown) within a BOP frame 2 which is located atop a well head 23 (best shown in FIG. 5 ). It comprises vertical beam members 5 along which are positioned axially movable vertical arms 9 , which are preferably telescopic having one upper portion and a lower portion, the lower portion being slidable through the upper portion. This is clear from FIG. 1 . The locking devices 7 are located along the slidable lower portion of the arms 9 . The BOP 1 rests on the well head 23 (best shown in FIG. 5 ). As known to persons skilled in the art, the christmas tree 6 , at the basal portion atop the well head 23 (shown in FIG. 5 ) may or may not be there. Tubular members such as risers (not shown) are connected to the BOP. The telescopic arms also comprise a suitably located winch device 10 for axial movement of the locking device 7 . As can be seen from FIG. 1 the locking device 7 locks the BOP on horizontal beams 3 , 4 of the well template (best shown as item 15 in FIG. 5 ). These locking devices are effective in firmly locking the BOP along several points on the well template, during riser operation, for achieving the objects of the present invention, as described hereinbefore. The axially moving telescopic arms 9 is further illustrated in FIGS. 2 , 3 and 4 , showing one such arm. A winch device 10 is suitably located on the telescopic arm 9 for facilitating its axial movement in upward direction by winching action, as will be understood by persons skilled in the art. The winch has a cable arrangement 11 , as shown in the accompanying FIG. 3 . This arrangement facilitates withdrawal of the lower portion of the telescopic arm in upward direction, along which the locking devices are located. FIG. 4 is a sectional view taken along the line A-A in FIG. 3 which preferably shows several handles 13 a , 13 b and 13 c . Each handle is pre-tensioned by a spring 14 and acts against a stop plate 12 on the telescopic arm 9 . The pair of handles 13 a are pulled preferably by an ROV, so that the lower portion of the telescopic arm 9 , having the locking devices, falls downward, thus employing the locking devices 7 . It would be clear from the accompanying FIG. 1 , that the locking device 7 is located at the lower portion of the telescopic arm 9 and is lowered on the well head components by downward and axial movement of the telescopic arm 9 . How this movement is caused, has been explained in the concluding portion of the preceding paragraph. This mechanism of employing the locking devices works irrespective of the distance between the well template and the initial position of the arms 9 . The locking devices are also adapted to function irrespective of this distance. The handles 13 c are preferably applied to hold up the lower portion of the telescopic arm 9 , having the locking devices 7 . The handles 13 b are preferably applied, for parking the telescopic arms, when not in use. FIG. 5 illustrates four well heads 23 and a BOP on top of one well head. It also shows a well template 15 which supports the well head and along which the locking devices 7 are connected at different points on the well template 15 . As known to persons skilled in the art, the well template rests on the sea bed in deep sea drilling projects, for supporting the well head. The well template 15 is preferably supported on the supporting columns, such as suction anchors 16 . The locking devices are landed on the well template in the manner as stated before which involves a simple and effective operation irrespective of the distance, but landing them correctly, is very crucial. This may be done, for example, from the deck of an offshore vessel. The locking device 7 as shown in FIG. 6 comprises a spindle 17 partially housed in a hydraulic cylinder 17 ′, as shown in this figure. It also comprises clamping arms 19 , a main frame 21 , two guard members 20 running from end to end of the clamping arms 19 on either side, hinged levers 18 (only one set shown), operable with either of the clamping arms 19 . The spindle 17 is fixed on a column 22 at the lower end of the telescopic arm 9 , which is movable axially with the axial movement of the corresponding telescopic arm 9 . As shown in FIG. 1 several locking devices 7 are located along several points, near well template 15 . All such locking devices lock the BOP on the well template 15 along several points on the template 15 . Consequently, there is a firm grip which disallows/substantially prevents the BOP from movement due to bending during riser operation. The FIG. 6 shows the locking device in locked position. As stated before, perfect locking is achieved by this technology, irrespective of the distance between the column 22 and the well template 15 . The FIG. 7 is an axial cut section along the vertical axis of the device illustrated in FIG. 6 for the sake of understanding. It shows some of the important features by virtue of which, the locking device grips the well template 15 after landing on the same. The spindle 17 is equipped with outer threads 24 . An inner wedge portion 26 has inner threads 25 which are adapted to mesh with the threads 24 of the spindle 17 . There also exists outer wedge shaped portion 27 along the outer portion of the inner sleeve 26 . How these portions contribute to effective locking, is explained hereinafter. Now the operation of the locking device 7 is explained with reference to FIGS. 8 to 10 . These figures, as can be seen show different operational positions of the locking device and these figures represent an axial cut section along the vertical axis of the device illustrated in FIG. 6 for the sake of understanding. FIG. 8 shows a position when the locking device is yet to be locked on the template 15 . This figure also clearly shows the different chambers in the hydraulic cylinder 17 ′ and how the spindle 17 is attached to the column 22 . Ideally, the spindle 17 is attached via a spherical ball bearing 22 ′. This allows the spindle to move and allow for taking up any misalignments. The other identical reference numerals represent identical features as in FIG. 7 . FIG. 9 shows a position where the column 22 has come down and landed the locking device 7 on the template beam 15 . The abutment against the template beam presses the supporting frame 21 upwards. Thereby, the hinged levers 18 act to swing the clamping arms 19 downwards so that they come to rest against the template beams and grips around these. The hydraulic cylinder is powered by hydraulic pressure from a hydraulic fluid. As can be seen from the FIGS. 8 to 10 the cylinder has a bottom chamber 32 and an upper chamber 33 . In the hydraulic cylinder 17 ′ there is also a piston 30 , which is pre-tensioned in the downward direction by a spring 31 . A hydraulic pressure in the upper chamber of the hydraulic cylinder 17 ′ acts against the spring 31 , so that the piston 30 is in its uppermost position when the clamping arms are being actuated for gripping. The hinged levers 18 actually act as leaf springs and those act to force the clamping arms 19 inwardly when the distance between the main frame 21 and the column 22 is reduced due to the main frame 21 pressing down on the beam 3 , 4 and thereby being pushed upward. The leaf spring 18 may have one arm only and having at least two arms is not mandatory. In FIG. 10 the clamping arms 19 have now closed by means of the hinged levers 18 and the grip on the template 15 is completed. As stated in the preceding paragraph, the hinged levers 18 play the role of leaf springs to force the clamping arms 19 inwardly. The guard member 20 ensures that the gripper assumes the correct position on the template beam. When the clamping arms 19 have clamped the beam 3 , 4 of the template 15 , the hydraulic pressure in the hydraulic cylinder 17 ′ is released and the spring 31 actuates the lock by pushing the piston downward. The piston presses against the outer wedges 27 via pins 34 and thereby forces the outer wedges downward. The outer wedges 27 press radially against and forces the inner wedges 26 inward until their inner threads 25 mesh with the outer threads of the spindle 17 . The inner and outer wedges thereby fixes the spindle 17 relative to the main frame 21 , preventing the main frame 21 from moving. Thereby the spring action from the levers 18 maintains their force on the clamping arms 19 and prevents these from swinging upwards again. Similar locking takes place along all points on the beam where respective locking devices are located and so, a firm locking of the BOP on beam 15 supporting the well head is achieved. This ensures substantial prevention of the well head from movement due to bending during riser operation with the BOP, thereby reducing the fatigue and risk of failure of the well head and increasing its lifespan. As explained in the preceding paragraphs, the securing of the lock is largely effected by the hydraulic cylinder 17 ′, the spring member 31 , the piston 30 , the inner and outer wedges 26 , 27 and the spindle 17 . The details of the spring member and the piston arrangement have not be illustrated in detail in the drawings, but a person of skill will have no problem understanding how this works in principle. It should be understood to persons skilled in the art, particularly with reference to the description of FIGS. 8 , 9 and 10 that securing of the gripping of the well template 15 by the clamping arms 19 take place by a spindle-cam mechanism. This spindle cam mechanism involves mutual operation of the spindle 17 , the spring member and the piston arrangement of the hydraulic cylinder 17 ′, the spring leaves 18 and the clamping arms 19 . All these coherently facilitate, clamping the BOP 1 firmly on the template 15 by the locking devices 7 . During unlocking of the BOP, the hydraulic pressure is applied to the hydraulic cylinder 17 ′ opposite to the spring member and the locking devices just operate in the opposite way as will be understood to persons skilled in the art. The present invention has been described with reference to some preferred embodiments and some drawings for the sake of understanding only and it should be clear to persons skilled in the art that the present invention includes all legitimate modifications within the ambit of what has been described hereinbefore and claimed in the appended claims.

A well head system for application in sub sea well exploration comprising a well head ( 23 ) having a well head housing secured to a well casing, at least one valve stack, e.g. a BOP ( 1 ) located atop said well head ( 23 ). The valve stack is removably locked on a well template ( 15 ) supporting said well head by a plurality of locking devices ( 7 ). Also described is a locking device comprising two opposite clamping arms ( 19 ) hingedly attached to a main frame ( 21 ). The Main frame is slidable relative to a spindle ( 17 ) and can be selectively secured to the spindle ( 17 ).

FIELD OF THE INVENTION The present invention relates to printed circuit boards (PCBs). More particularly, the present invention relates to alterations in a PCB ground plane to remove resonance. BACKGROUND OF THE INVENTION Printed circuit boards (PCBs) are widely used in the electronics and computer industries to mechanically and electrically couple individual components. A “motherboard” in a personal computer (PC), used to mount, and connect, a central processing unit (CPU) with other associated component is but one common example of a PCB. Generally, a PCB comprises a number of layers through which electrical signals may be routed, separated by dielectric layers. The layers for routing electrically isolated, or the entire layer may be electrically conductive. Conductive layers may be used to efficiently provide access to a particular voltage level, or voltage plane, over the entire area of the PCB. PCBs with one or more power planes, at voltages, such as V dd , and one or more ground planes are relatively common. One design choice in routing signals within a PCB, is between routing on the top layer (microstrip routing) or routing in one of the inner layers (stripline routing). Microstrip routing typically provides faster signal speeds or “flight times” at the expense of requiring more complete connections to the routing traces. Signal speeds of 153 ps/in for microstrip routing and 170 ps/in for stripline routing are typical. An advantage of stripline routing is that such a routing makes it easier to electrically isolate the signals using isolation lines and ground planes. The design of a trace, or conductor for a particular signal path, depends on many factors. Two important factors being the locations of the points to be connected and the required impedance of the trace. The required impedance will typically be set by the components connected by the trace, with the actual impedance a function of the inductance and capacitance of the particular trace design. Eventually, the length, width, and geometry of the trace are defined for an acceptable signal routing scheme. However, there are combinations of clock speeds and signal values that degrade the quality of signal transmissions for a given signal routing scheme. Resonances within a PCB may occur when a signal on a single signal path, although isolated from other signals on the PCB, oscillates at, or near, an integer multiple of signal transit time. Such resonance may seriously degrade the performance of the PCB. FIG. 1 depicts the stripline routing of traces 2 within a single layer of a PCB 4 . The routing shown in FIG. 1 may be used within a RAMBUS RIMM module containing dynamic random access memory (DRAM) devices, RDRAMs, as licensed by Rambus, Inc. of Mountain View, Calif. The signal routing in FIG. 1 does not reflect an embodiment of the present invention. This signal routing may be susceptible to resonance under certain conditions. Although the present invention is not intended to be limited to any particular PCB 4 , or trace 2 design, an embodiment of the present invention may be used to improve signal transmission characteristics in a device such as a RDRAM. That is, under some combinations of clock speeds and signal values, resonance may decrease device performance and an embodiment of the present invention may be used to prevent, or reduce, the decrease in performance. SUMMARY OF THE INVENTION A method and apparatus for decreasing resonance in a printed circuit board (PCB) uses cuts in a ground plane to slow a signal passing through the ground plane. Cuts in the ground plane may be used alone or in conjunction with the lengthening of signal traces. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows signal trace routing within one layer of a PCB. FIG. 2 shows a detailed depiction of a signal trace within one layer of a PCB together with grounded isolation lines. FIG. 3 is a cross section through a PCB showing the multiple layers. FIGS. 4A-4B depicts two layouts of a signal trace of a PCB. FIG. 5 depicts a cut in a PCB ground plane in accordance with an embodiment of the present invention. FIG. 6 illustrates the details of a zipper cut pattern in accordance with an embodiment of the present invention. DETAILED DESCRIPTION An embodiment of the present invention is directed to improving the signal transmission characteristics within a printed circuit board (PCB) by removing resonance from a ground plane. An embodiment of the present invention will be described in the context of a RAMBUS RIMM module. The present invention is not, however, intended to be limited to any such particular application. Those of ordinary skill in the art will, with the benefit of the herein disclosure, be able to use the present invention in a wide variety of electronic devices where resonance may cause problems at certain clock speeds and/or with certain combinations of signal values. In the design of traces 2 for high speed electronic devices, such as, but not limited to, PCB 4 , great care is often taken to avoid interference with signals carried by traces 2 . FIG. 2, shows one such design that may be used to shield a signal carried by trace 2 . It is an enlarged view of trace 2 on a layer of PCB 4 . Trace 2 is a 18 mil wide conductor, that is located between two 5 mil wide insulators 6 . Also bordering insulators 6 , on each side of trace 2 , are two 5 mil wide isolation lines 8 . Isolation lines 8 are typically conductive and are preferably grounded to a single common ground. In a PCB 4 , each of the signal traces 2 may be surrounded on the particular “horizontal” layer within PCB 4 , by insulators 6 and isolation lines 8 . In addition, signal trace 2 may be shielded vertically within PCB 4 . Turning now to FIG. 3, a cross section through a PCB, a particular layer 10 with traces 2 , such as shown in FIG. 1, makes up but one horizontal layer with a PCB 4 . Above and below layer 10 may be dielectric layers 12 and ground planes 14 . With such a design, trace 2 is surrounded both horizontally and vertically with a dielectric and a ground in order to isolate trace 2 and to minimize the effects of other signals on the one carried by trace 2 . There are, however, situations where such isolation alone is not effective, resulting in poor device performance, such as single bit errors. One use of PCBs 4 is to allow standard configurations, such as a standard connect pin layout on a device, while using dissimilar component level devices to make up the device. A common example, known to those of ordinary skill in the art, would be single inline memory modules (SIMMs) such as a 72-pin SIMM specified by the Joint Electronic Device Engineering Council (JEDEC). Although many memory components, of varying sizes, may be used by various manufacturers, the resulting device will “plug-in” to a standard 72-pin SIMM socket. Thus, the standardization of a particular PCB 4 layout, such as size and connection geometry, can be valuable. This is the case even though such a standard layout may not be “optimal” for each particular embodiment in design of performance. The RAMBUS RIMM modules, while not eclipsing SIMMs in the total number of devices sold, have gained popularity and their geometry is somewhat “fixed” by the consistent use of that geometry. Even though the present geometry of an RAMBUS RIMM module may not be optimal for all situations, changing that geometry would incur costs. The speed or transit times of signals to and from PCB 4 depend on the signal path, or traces 2 , and the individual devices through which the signal will pass. A RAMBUS RIMM module type PCB 4 with 4 RDRAMs have a signal transit time of about 1.25 ns. For a 6 RDRAM configuration the transit time is about 1.4 ns. These times are essentially fixed for a given PCB 4 layout. High speed devices, such as a RAMBUS RIMM module, often have tight timing budgets, such as a maximum skew between a clock and data signal of about 125 ps. The layout of traces 2 in FIG. 1 reflects such a tight timing budget. The lengths of the many traces 2 are equal, within approximately 10 mils, resulting in similar transit times over the various traces 2 . Most digital electronic devices use zeros and ones, corresponding to two different voltage levels, to represent data signals. In some data combinations, such as but not limited to, 01010101 . . . , the signal oscillates between the two voltage levels. When, because of a particular clock speed and data combination, the voltage oscillation period nearly matches the transit times of signals through PCB 4 , the resulting resonance may significantly decrease signal transmission performance. Data is transferred by a RAMBUS RIMM module at 600 MHz, 712 MHz or 800 MHz, depending on the particular application. Unfortunately, these frequencies correspond to periods of 1.67 ns, 1.40 ns and 1.25 ns, respectively, which are close to some signal transit times. While not all data value combinations may lead to resonance, certain combinations might. For example, a string of zeros (or ones) may not cause a voltage switch, while the data string 00110011 . . . may well cause problems because the data transfer rate might be an integer multiple of the voltage fluctuation rate. Because a device may see almost any combination of data values, it must be designed for the worst case. The effect of resonance on signal performance is negative; it introduces instability. An embodiment of the present invention makes relatively small adjustments in the signal paths to avoid signal transit times near the data transfer rate in order to avoid resonance problems. That is, the two periods will preferably differ enough to avoid a resonance range. For example, increasing the signal transit time for a 4 RDRAM RAMBUS RIMM module from 1.25 ns to 1.6 ns significantly decreases resonance related problems. Preferably, the transit times of signals would differ from multiples of the period of the data transfer rate. One way to achieve this result, without altering the clock speed, is to change the lengths of traces 2 slightly to “detune” PCB 4 . FIGS. 4A and 4B show one embodiment of lengthening traces 2 . However, such lengthening of traces 2 does not directly effect resonance problems within a ground plane. In one case, detuning traces 2 still left the ground plane with a resonance caused fluctuation of approximately 100 mV. Eliminating such a fluctuation in the ground plane increases the signal-to-noise (SIN) ratio, which tends to decrease data transmission errors. Electrical signals to and from any device typically require two conductors; typically a trace and a ground plane in PCB 4 . Since a ground plane is typically a conductive layer of PCB 4 , not individual traces 2 , increasing the signal transit times through the ground plane requires different techniques than the lengthening used for traces 2 . An embodiment of the present invention uses cuts in the conductive layer of a ground plane to reduce resonance and improve overall signal performance. Preferably, the cuts in a ground plane are coordinated with the laying out and lengthening of traces 2 . FIG. 5 illustrates a PCB 4 with cuts made to a ground plane, in accordance with an embodiment of the present invention. Traces 2 have been lengthened, similar to that shown in FIG. 4 B. The locations of ground plane cuts 16 are preferably coordinated with the locations of traces 2 . Although only a single trace 2 layout is shown in FIG. 5, the location of all traces 2 and ground plane cuts 16 on PCB 4 are preferably coordinated such that cuts 16 terminate at least 10 mils from a trace 2 . In one embodiment of the present invention, the locations of ground plane cuts 16 are similar in each ground plane layer within PCB 4 . That is, cuts 16 are vertically aligned. In one embodiment of the present invention, cut 16 is continuous. That is, there is almost no electrical current across cut 16 . As is shown in FIG. 5, cuts 16 are preferably made substantially perpendicular to the long axis of PCB 4 . Another embodiment uses a non-continuous “zipper cut.” FIG. 6 illustrates such a zipper cut pattern. Along the axis of cut 16 , a series of approximately 10 mil long by 5 mil wide holes are created in the ground plane at spacing of 20 mil, center-to-center. The effect of a zipper cut pattern is a smaller decrease in signal transit times through a ground plane than a continuous cut 16 at the same location.

A method for decreasing resonance in a printed circuit board (PCB) uses cuts in a ground plane to slow a signal passing through the ground plane. Cuts in the ground plane may be used alone or in conjunction with the lengthening of signal traces. Slowing the signal passing through the ground plane enables a mismatch between the signal transit time of the ground plane and a signal oscillation period of the circuit board to be obtained. The mismatch results in decreased resonance.

PRIORITY INFORMATION This application is a continuation of U.S. patent application Ser. No. 09/900,475, filed Jul. 6, 2001 now U.S. Pat. No. 6,565,397, which is based on Japanese Patent Application No. 2000-169273, filed Jun. 6, 2000, the entire contents of which is hereby expressly incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present application relates to an engine control arrangement for controlling a watercraft, and more particularly relates to an engine management system that controls engine speed in order to reduce noise. 2. Description of the Related Art Watercraft, including personal watercraft and jet boats, are often powered by at least one internal combustion engine having an output shaft arranged to drive one or more water propulsion devices. Occasionally, engine revving is conducted out of the water in order to test the engine or to use exhaust pressure to drain salt water that has entered the engine during cruising. Unfortunately, since there is no water resistance applied to the propulsion device when revving the engine out of the water, the engine speed may easily reach or exceed a maximum safe speed when the throttle is slightly applied, which causes extremely loud noise. SUMMARY OF THE INVENTION The present application is directed to an engine control arrangement of the type used to power a watercraft, which controls the engine speed and prevents the engine from revving too high when out of the water, thus preventing excessively loud noise. One aspect of the preferred embodiments is an engine speed control system for a watercraft that is propelled by a stream of water generated by a propulsion unit driven by an engine. The engine control system comprises means for detecting whether the propulsion unit is generating a stream of water. The system also comprises a controller responsive to the means for detecting, the controller limiting the maximum engine speed to a first speed when the propulsion unit is generating the stream of water, the controller limiting the maximum engine speed to a second speed, lower than the first speed, when the propulsion unit is not generating the stream of water. In one preferred embodiment of this first aspect, the means for detecting comprises a first sensor that senses ambient atmospheric pressure and a second sensor that senses a pressure responsive to the movement of the stream of water. The means for detecting compares the ambient atmospheric pressure and the pressure responsive to the movement of the stream of water to determine whether the stream of water is being generated by the propulsion unit. In one particularly preferred embodiment, the propulsion unit includes an inlet that receives water, and the second sensor is positioned in the inlet such that the pressure sensed by the second sensor decreases with increasing water flow and increases with decreasing water flow. In an alternative particularly preferred embodiment, the propulsion unit includes an outlet that conveys the stream of water generated by the propulsion unit, and the second sensor is positioned in the outlet such that the pressure sensed by the second sensor increases with increasing water flow and decreases with decreasing water flow. In an alternative embodiment, the means for detecting comprises a sensor that responds to the speed of the watercraft to determine whether the stream of water is being generated by the propulsion unit. In accordance with a particular aspect of the preferred embodiment, the controller reduces the engine speed to the second speed only after the controller determines that the propulsion unit is not generating the stream of water for a predetermined time duration. For example, the predetermined time duration is advantageously at least 5 seconds. In one exemplary embodiment, the first speed is 7,000 revolutions per minute, and the second speed is 4,000 revolutions per minute. A second aspect of the preferred embodiments is a method for reducing engine speed and thereby reducing engine noise of a watercraft propelled by a stream of water generated by a propulsion unit driven by an engine when the watercraft is out of the water. The method comprises sensing whether the watercraft is out of the water, controlling the engine speed to a first maximum speed when the watercraft is in the water, and controlling the engine speed to a second maximum speed when the watercraft is out of the water, the second maximum speed lower than the first maximum speed. In one preferred embodiment of this second aspect, the sensing step comprises comparing a first pressure with a second pressure to determine whether water is flowing through the propulsion unit. In a particularly preferred embodiment, the first pressure is ambient atmospheric pressure, and the second pressure is determined by the flow of water through the propulsion unit. In a first alternative of this particularly preferred embodiment. the second pressure is measured at an inlet to the propulsion unit, the second pressure decreasing with increasing flow of water and decreasing with increasing flow of water. In a second alternative of this particularly preferred embodiment, the second pressure is measured at an outlet to the propulsion unit, the second pressure decreasing with decreasing flow of water and increasing with increasing flow of water. In an alternative embodiment, the sensing step comprises sensing the speed of the watercraft to determine whether water is flowing through the propulsion unit. In particular aspects of the method, the engine speed is controlled to the second speed only after the method determines that the propulsion unit is not generating the stream of water for a predetermined time duration. In an exemplary embodiment of the method, the predetermined time duration is at least 5 seconds. In particular embodiments of the method, the first speed is 7,000 revolutions per minute, and the second speed is 4,000 revolutions per minute. BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects of the preferred embodiment of the invention are described in detail below in connection with the accompanying drawings in which: FIG. 1 is a side view of a personal watercraft of the type powered by an engine having an engine control arrangement in accordance with the present invention, the engine and other watercraft components positioned within the watercraft illustrated in phantom; FIG. 2 is a cross-sectional end view of the watercraft taken along the line 2 — 2 of FIG. 1 , illustrating the engine therein and a portion of the exhaust system with a catalyst in cross-section; FIG. 3 is a cross sectional side view of the jet propulsion unit illustrating the pressure sensors therein; and FIG. 4 is a block diagram showing a control routine constructed and operated in accordance with an embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment is an engine control arrangement for an engine of the type utilized to power a watercraft, including a personal watercraft or a jet boat. FIG. 1 illustrates a watercraft 10 comprising a top portion or deck 12 and a lower portion 14 . A gunwale 16 defines the intersection of the deck 12 and the lower portion 14 . A cover 18 is provided in the front upper side of the deck 12 . A storage cover 20 is mounted on the forward side of the cover 18 . A fuel tank 22 (shown in phantom) is located in the lower portion 14 . The rear portion of the deck 12 provides a seat base 24 . A seat 26 is positioned on the seat base 24 . A steering handle 28 is provided adjacent the seat 26 for use by a user in directing the watercraft 10 . As illustrated in FIG. 2 , a respective bulwark 30 extends upwardly along each side of the watercraft 10 . A respective footstep area 32 , 34 is defined between the seat base 24 and each bulwark 30 . As illustrated in FIGS. 1 and 2 , the watercraft 10 includes an engine 36 positioned in an engine compartment 38 . The engine 36 is preferably a two-cylinder, two-cycle engine. The engine 36 may have as few as one, or more than two cylinders, as will be appreciated by one skilled in the art. As illustrated in FIG. 2 , the engine 36 is connected to the lower portion 14 via several engine mounts 40 . The mounts 40 are connected to upwardly extending supports 42 , which are connected to the lower portion 14 of the watercraft 10 . The engine 36 is preferably at least partially accessible through a maintenance opening 44 accessible by removing the seat 26 . The engine 36 has a crankshaft 46 (see FIG. 2 ) which is in driving relation with an impeller shaft 48 (see FIG. 3 ) through a coupling 50 (see FIG. 1 ). The impeller shaft 48 rotationally drives a means for propelling water (e.g., an impeller 52 ) in a propulsion unit 54 , which unit extends out the stern portion of the watercraft 10 . The propulsion unit 54 includes a propulsion passage 56 having an intake port (i.e., a water inlet 58 ). The water inlet 58 extends through the lower portion 14 of the watercraft 10 . The passage 56 also has an outlet 60 that has a discharge positioned within a nozzle 62 . The nozzle 62 is mounted for movement up and down and to the left and right, whereby the direction of the propulsion force for the watercraft 10 may be varied. The engine 36 includes a cylinder block 64 having a cylinder head 66 connected thereto and cooperating therewith to define a combustion chamber 68 defined by cylinder wall 70 within the block 64 and by a recessed area 72 in the cylinder head 66 . A piston 74 is movably mounted in the combustion chamber 68 , and is connected to a crankshaft 46 via a connecting rod 76 , as is well known in the art. A second combustion chamber (not shown) is positioned in line with the first combustion chamber 68 and has similar construction. Preferably, the engine 36 is tilted so that the combustion chambers have a centerline C which is offset from a vertical axis V. As is well known in the art, this arrangement keeps the vertical profile of the engine small, such that the watercraft 10 has a low center of gravity. The engine 36 includes means (e.g., an intake manifold 78 ) for providing an air and fuel mixture to each combustion chamber. The intake manifold 78 has a silencer 80 mounted on the input end. Preferably, air is drawn into the engine compartment 38 and then drawn into the silencer 80 and delivered to the combustion chambers via the intake manifold 78 . As illustrated in FIG. 2 , fuel is delivered to a fuel injector 82 through a fuel rail 84 . It is contemplated that the fuel may be provided by indirect or direct fuel injection, as well as via carburation, as known in the art. As shown in FIG. 2 , a catalyst 88 is located in the center of an exhaust pipe 86 . The exhaust pipe 86 wraps around the front of the engine 36 and extends to the rear of the watercraft 10 where it connects to a water lock 90 . An exhaust outlet 92 is located below a water a level L 1 when the watercraft is in the stationary position. The exhaust outlet 92 is located above a water level L 2 when the watercraft is planing. A suitable ignition system is provided for igniting the air and fuel mixture provided to each combustion chamber. Preferably, this system comprises a spark plug (not shown) corresponding to each combustion chamber. The spark plugs are preferably fired by a suitable ignition system. It is contemplated that the ignition system incorporates preprogrammed ignition maps to control the ignition spark advance curve. In a similar way, both the indirect and direct fuel injection systems incorporate pre-programmed fuel delivery maps to control fuel injection timing issues. The ignition maps and the fuel delivery maps are software that are part of a control system. As shown in FIG. 2 , the control system includes an atmospheric pressure sensor 94 , which can be mounted in the engine compartment 38 or mounted directly on the engine 36 . As shown in FIG. 3 , an inlet pressure sensor 96 is mounted at a ramp 98 at the forward side of the water inlet 58 . As further shown in FIG. 3 , the inlet pressure sensor 96 can be replaced by a nozzle pressure sensor 99 mounted on the outlet 60 . The nozzle pressure sensor 99 detects nozzle pressure downstream of a set of stationary blades 100 . Furthermore both of the sensors 96 and 99 may be replaced with a watercraft speed sensor. The control system operates by a control routine as best seen in FIG. 4 . The program starts and then moves to a step P 1 to read the condition of the inlet pressure sensor 96 and determine if the inlet pressure is lower than the atmospheric pressure measured by the pressure sensor 94 . If the inlet pressure is lower, meaning water is traveling into the water inlet 58 , then the program moves to a step P 2 to allow the maximum engine rpm to be 7000. The program returns to the start of the control routine and repeats the reading and decision process as long as the engine is running. If however, at the step P 1 , the inlet pressure measured by the sensor 96 is greater than or equal to the atmospheric pressure measured by the sensor 94 , the program moves to a step P 3 . In the step P 3 the program determines whether the inlet pressure measured by the sensor 96 has been greater than or equal to the atmospheric pressure for more than five seconds. If the measured inlet pressure has been greater than or equal to the atmospheric pressure for longer than five seconds, then the program moves to a step P 4 and limits the maximum engine rpm to 4000. The program returns to the start of the control routine and repeats the forgoing steps. If, at the step P 3 , the measured inlet pressure has been greater than or equal to the atmospheric pressure for less than five seconds, then the program moves to the step P 2 to allow the maximum engine rpm to be 7000. The program returns to the start of the control routine and repeats the forgoing steps. The five-second delay period allows sufficient time for the control system to permit for short durations of out-of-water operation, caused for example, by porpoising or jumping, which commonly occurs with watercraft operation. The maximum engine speed is not reduced unless the watercraft remains out of the water for more than five seconds. If the pressure sensor 96 is replaced with the nozzle pressure sensor 99 , the control sequence will determine in the step P 1 whether the nozzle pressure is higher than the atmospheric pressure measured by the sensor 94 . If the nozzle pressure is not higher than the atmospheric pressure, then in the step P 3 , the control sequence determines if the nozzle pressure was not higher than the atmospheric pressure for more than five seconds. Similarly, if a watercraft speed sensor is used instead of the pressure sensor 82 , then in step P 1 , the control sequence determines whether or not the watercraft speed is greater than a predetermined speed. If the watercraft speed is not greater than a predetermined speed, then in the step P 3 , the control sequence determines if the watercraft speed was less than the predetermined speed for more than 5 seconds before limiting the maximum engine speed. In the preferred embodiment, the operational state of the watercraft can be advantageously determined using the pressure sensor 96 , the nozzle pressure sensor 99 , or the speed sensor, as long as the control sequence can determine if the watercraft is on the water or how long it is out of the water. The inlet pressure sensor 96 can be advantageously located in different areas of the water passage as long as it is located in the general vicinity of the water inlet 58 . If the control system regulates the engine speed using the ignition system, the firing of one or any of the cylinders may be completely or intermittently stopped, or the firing of all cylinders may be intermittently stopped. Similarly, if the control system uses the fuel control to regulate engine speed, the fuel injection of one or any of the cylinders may be completely or intermittently stopped, or the fuel injection from all the cylinders may be intermittently stopped. Thus, from the foregoing description, it should be readily apparent that the described embodiments very effectively control engine speed in order to reduce noise. Comparing the pressure measured in the water inlet to the atmospheric pressure in order to determine the operating condition of the watercraft accomplishes this. Of course, the foregoing description is that of preferred embodiments of the invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.

An engine control system and a method control the engine speed of a watercraft that is propelled by a stream of water generated by propulsion unit driven by an engine. The system and method detect whether the propulsion unit is generating the stream of water. The system and method limit the maximum engine speed to a first speed when the propulsion unit is generating the stream of water and limit the maximum engine speed to a second speed, lower than the first speed, when the propulsion unit is not generating the stream of water.

This application is a continuation of application Ser. No. 08/703,015 filed Aug. 26, 1996 which is a division of application Ser. No. 467,039, filed Jun. 6, 1995, both now abandoned. BACKGROUND OF THE INVENTION The invention relates in general to a movable barrier operator for opening and closing a movable barrier or door. More particularly, the invention relates to a garage door operator that can learn force and travel limits when installed and can simulate the temperature of its electric motor to avoid motor failure during operation. A number of garage door operators have been sold over the years. Most garage door operators include a head unit containing a motor having a transmission connected to it, which may be a chain drive or a screw drive, which is coupled to a garage door for opening and closing the garage door. Such garage door openers also have included optical detection systems located near the bottom of the travel of the door to prevent the door from closing on objects or on persons that may be in the path of the door. Such garage door operators typically include a wall control which is connected via one or more wires to the head unit to send signals to the head unit to cause the head unit to open and close the garage door, to light a worklight or the like. Such prior art garage door operators also include a receiver and head unit for receiving radio frequency transmissions from a hand-held code transmitter or from a keypad transmitter which may be affixed to the outside of the garage or other structure. These garage door operators typically include adjustable limit switches which cause the garage door to operate or to halt the motor when the travel of the door causes the limit switch to change state which may either be in the up position or in the down position. This prevents damage to the door as well as damage to the structure supporting the door. It may be appreciated, however, that with different size garages and different size doors, the limits of travel must be custom set once the unit is placed within the garage. In the past, such units have had mechanically adjustable limit switches which are typically set by an installer. The installer must go back and forth between the door, the wall switch and the head unit in order to make the adjustment. This, of course, is time consuming and results in the installer being forced to spend more time than is desirable to install the garage door operator. A number of requirements are in existence from Underwriter's Laboratories, the Consumer Product Safety Commission and the like which require that garage door operators sold in the United States must, when in a closing mode and contacting an obstruction having a height of more than one inch, reverse and open the door in order to prevent damage to property and injury to persons. Prior art garage door operators also included systems whereby the force which the electric motor applied to the garage door through the transmission might be adjusted. Typically, this force is adjusted by a licensed repair technician or installer who obtained access to the inside of the head unit and adjusts a pair of potentiometers, one of which sets the maximal force to be applied during the closing portion of door operation, the other of which establishes the maximum force to be applied during the opening of door operation. Such a garage door operator is exemplified by an operator taught in U.S. Pat. No. 4,638,443 to Schindler. However, such door operators are relatively inconvenient to install and invite misuse because the homeowner, using such a garage door operator, if the garage door operator begins to bind or jam in the tracks, may likely obtain access to the head unit and increase the force limit. Increasing the maximal force may allow the door to move passed a binding point, but apply the maximal force at the bottom of its travel when it is almost closed where, of course, it should not. Another problem associated with prior art garage door operators is that they typically use electric motors having thermostats connected in series with portions of their windings. The thermostats are adapted to open when the temperature of the winding exceeds a preselected limit. The problem with such units is that when the thermostats open, the door then stops in whatever position it is then in and can neither be opened or closed until the motor cools, thereby preventing a person from exiting a garage or entering the garage if they need to. SUMMARY OF THE INVENTION The present invention is directed to a movable barrier operator which includes a head unit having an electric motor positioned therein, the motor being adapted to drive a transmission connectable to the motor, which transmission is connectable to a movable barrier such as a garage door. A wired switch is connectable to the head unit for commanding the head unit to open and close the door and for commanding a controller within the head unit to enter a learn mode. The controller includes a microcontroller having a non-volatile memory associated with it which can store force set points as well as digital end of travel positions within it. When the controller is placed in learn mode by appropriate switch closure from the wall switch, the door is caused to cycle open and closed. The force set point stored in the non-volatile memory is a relatively low set point and if the door is placed in learn mode and the door reaches a binding position, the set point will be changed by increasing the set point to enable the door to travel through the binding area. Thus, the set points will be dynamically adjusted as the door is in the learn mode, but the set points will not be changeable once the door is taken out of the learn mode, thereby preventing the force set point from being inadvertently increased, which might lead to property damage or injury. Likewise, the end of travel positions can be adjusted automatically when in the learn mode because if the door is halted by the controller, when the controller senses that the door position has reached the previously set end of travel position, the door will then be commanded by a button push from the wall switch to keep travelling in the same direction, thereby incrementing or changing. The end of travel limits are set by pushing the learn button on the wall switch which causes the door to travel upward and continue travelling upward until the door has travelled as far as the operator wishes it to travel. The operator disables the learn switch by lifting his hand from the button. The up limit is then stored and the door is then moved toward the closed position. A pass point or position normalizing system consisting of a ring-like light interrupter attached to the garage door crosses the light path of an optical obstacle detector signalling instantaneously the position of the door and the door continues until it closes, whereupon force sensing in the door causes an auto-reverse to take place and then raises the door to the up position, the learn mode having been completed and the door travel limits having been set. The movable barrier operator also includes a combination of a temperature sensor and microcontroller. The temperature sensor senses the ambient temperature within the head unit because it is positioned in proximity with the electric motor. When the electric motor is operated, a count is incremented in the microcontroller which is multiplied by a constant which is indicative of the speed at which the motor is moving. This incremented multiplied count is then indicative of the rise in temperature which the motor has experienced by being operated. The count has subtracted from it the difference between the simulated temperature and the ambient temperature and the amount of time which the motor has been switched off. The totality of which is multiplied by a constant. The remaining count then is an indication of the extant temperature of the motor. In the event that the temperature, as determined by the microcontroller, is relatively high, the unit provides a predictive function in that if an attempt is made to open or close the garage door, prior to the door moving, the microcontroller will make a determination as to whether the single cycling of the door will add additional temperature to the motor causing it to exceed a set point temperature and, if so, will inhibit operation of the door to prevent the motor from being energized so as to exceed its safe temperature limit. The movable barrier operator also includes light emitting diodes for providing an output indication to a user of when a problem may have been encountered with the door operator. In the event that further operation of the door operator will cause the motor to exceed its set point temperature, an LED will be illuminated as a result of the microcontroller temperature prediction indicating to the user that the motor is not operating because further operation will cause the motor to exceed its safe temperature limits. It is a principal aspect of the present invention to provide a movable barrier operator which is able to quickly and automatically select end of travel positions. It is another aspect of the present invention to provide a movable barrier operator which, upon installation, is able to quickly establish up and down force set points. It is still another aspect of the present invention to provide a movable barrier operator which can determine the temperature of the motor based upon motor history and the ambient temperature of the head unit. Other aspects and advantages of the invention will become obvious to one of ordinary skill in the art upon a perusal of the following specification and claims in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a garage having mounted within it a garage door operator embodying the present invention; FIG. 2 is a block diagram of a controller mounted within the head unit of the garage door operator employed in the garage door operator shown in FIG. 1; FIG. 3 is a schematic diagram of the controller shown in block format in FIG. 2; FIG. 4 is a schematic diagram of a receiver module shown in the schematic diagram of FIG. 3; FIGS. 5A-B are a flow chart of a main routine that executes in a microcontroller of the control unit; FIGS. 6A-G are a flow diagram of a learn routine executed by the microcontroller; FIGS. 7A-B are flow diagrams of a timer routine executed by the microcontroller; FIGS. 8A-B are flow diagrams of a state routine representative of the current and recent state of the electric motor; FIGS. 9A-B are a flow chart of a tachometer input routine and also determines the position of the door on the basis of the pass point system and input from the optical obstacle detector; FIGS. 10A-C are flow charts of the switch input routines from the switch module; and FIG. 11 is a schematic diagram of the switch module and the switch biasing circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and especially to FIG. 1, more specifically a movable barrier door operator or garage door operator is generally shown therein and referred to by numeral 10 includes a head unit 12 mounted within a garage 14. More specifically, the head unit 12 is mounted to the ceiling of the garage 14 and includes a rail 18 extending therefrom with a releasable trolley 20 attached having an arm 22 extending to a multiple paneled garage door 24 positioned for movement along a pair of door rails 26 and 28. The system includes a hand-held transmitter unit 30 adapted to send signals to an antenna 32 positioned on the head unit 12 and coupled to a receiver as will appear hereinafter. An external control pad 34 is positioned on the outside of the garage having a plurality of buttons thereon and communicates via radio frequency transmission with the antenna 32 of the head unit 12. A switch module 39 is mounted on a wall of the garage. The switch module 39 is connected to the head unit by a pair of wires 39a. The switch module 39 includes a learn switch 39b, a light switch 39c., a lock switch 39d and a command switch 39e. An optical emitter 42 is connected via a power and signal line 44 to the head unit 12. An optical detector 46 is connected via a wire 48 to the head unit 12. A pass point detector 49 comprising a bracket 49a and a plate structure 49b extending from the bracket has a substantially circular aperture 49c formed in the bracket, which aperture might also be square or rectangular. The pass point detector is arranged so that it interrupts the light beam on a bottom leg 49d and allows the light beam to pass through the aperture 49c. The light beam is again interrupted by the leg 49e, thereby signalling the controller via the optical detector 46 that the pass point detector attached to the door has moved passed a certain position allowing the controller to normalize or zero its position, as will be appreciated in more detail hereinafter. As shown in FIGS. 2 and 3, the garage door operator 10, which includes the head unit 12 has a controller 70 which includes the antenna 32. The controller 70 includes a power supply 72 which receives alternating current from an alternating current source, such as 110 volt AC, and converts the alternating current to +5 volts zero and 24 volts DC. The 5 volt supply is fed along a line 74 to a number of other elements in the controller 70. The 24 volt supply is fed along the line 76 to other elements of the controller 70. The controller 70 includes a super-regenerative receiver 80 coupled via a line 82 to supply demodulated digital signals to a microcontroller 84. The receiver is energized by a line 85 coupled to the line 74. The microcontroller 84 is also coupled by a bus 86 to a non-volatile memory 88, which non-volatile memory stores set points and other customized digital data related to the operation of the control unit. An obstacle detector 90, which comprises the emitter 42 and infrared detector 46 is coupled via an obstacle detector bus 92 to the microcontroller 84. The obstacle detector bus 92 includes lines 44 and 48. The wall switch 39 is connected via the connecting wires 39a to a switch biasing module 96 which is powered from the 5 volt supply line 74 and supplies signals to and is controlled by the microcontroller 84 via a bus 100 coupled to the microcontroller 84. The microcontroller 84, in response to switch closures, will send signals over a relay logic line 102 to a relay logic module 104 connected to an alternating current motor 106 having a power take-off shaft 108 coupled to the transmission 18 of the garage door operator. A tachometer 110 is coupled to the shaft 108 and provides a tachometer signal on a tachometer line 112 to the microcontroller 84. The tachometer signal being indicative of the speed of rotation of the motor. The power supply 72 includes a transformer 130 which receives alternating current on leads 132 and 134 from an external source of alternating current. The transformer steps down the voltage to 24 volts and feeds 24 volts to a pair of capacitors 138 and 140 which provide a filtering function. A 24 volt filtered DC potential is supplied on the line 76 to the relay logic 104. The potential is fed through a resistor 142 across a pair of filter capacitors 144 and 146, which are connected to a 5 volt voltage regulator 150, which supplies regulated 5 volt output voltage across a capacitor 152 and a Zener diode 154 to the line 74. Signals may be received by the controller at the antenna 32 and fed to the receiver 80. The receiver 80 includes a pair of inductors 170 and 172 and a pair of capacitors 174 and 176 that provide impedance matching between the antenna 32 and other portions of the receiver. An NPN transistor 178 is connected in common base configuration as a buffer amplifier. Bias to the buffer amplifier transistor 178 is provided by resistors 180. A resistor 188, a capacitor 190, a capacitor 192 and a capacitor 194 provide filtering to isolate a later receiver stage from the buffer amplifier 178. An inductor 196 also provides power supply buffering. The buffered RF output signal is supplied on a line 200, coupled between the collector of the transistor 178 and a receiver module 202 which is shown in FIG. 4. The lead 204 feeds into the unit 202 and is coupled to a biasing resistor 220. The buffered radio frequency signal is fed via a coupling capacitor 222 to a tuned circuit 224 comprising a variable inductor 226 connected in parallel with a capacitor 228. Signals from the tuned circuit 220 are fed on a line 230 to a coupling capacitor 232 which is connected to an NPN transistor 234 at its based 236. The transistor has a collector 240 and emitter 242. The collector 240 is connected to a feedback capacitor 246 and a feedback resistor 248. The emitter is also coupled to the feedback capacitor 246 and to a capacitor 250. The line 210 is coupled to a choke inductor 256 which provides ground potential to a pair of resistors 258 and 260 as well as a capacitor 262. The resistor 258 is connected to the base 236 of the transistor 234. The resistor 260 is connected via an inductor 264 to the emitter 242 of the transistor. The output signal from the transistor is fed outward on a line 212 to an electrolytic capacitor 270. As shown in FIG. 3, the capacitor 270 capacitively couples the demodulated radio frequency signal to a bandpass amplifier 280 to an average detector 282 which feeds a comparator 284. The comparator 284 also receives a signal directly from the bandpass amplifier 280 and provides a demodulated digital output signal on the line 82 coupled to the P32 pin of the Z86E21/61 microcontroller 84. The microcontroller 84 is energized by the power supply 72 and also controlled by the wall switch 39 coupled to the microcontroller by the leads 100. From time to time, the microcontroller will supply current to the switch biasing module 96. The microcontroller operates under the control of a main routine as shown in FIGS. 5A and 5B. When the unit is powered up, a power on reset is performed in a step 300, the memory is cleared and a check sum from read-only memory within the microcontroller 84 is tested. In a step 302, if the check sum and the memory prove to be correct, control is transferred to a step 304, if not, control is transferred back to the step 300. In the step 304, the last non-volatile state, which is indicative of the state of the operator, that is whether the operator indicated the door was at its up limit, down limit or in the middle of its travel, is tested for in a step 304 and if the last state is a down limit, control is transferred to a step 306. If it was an up limit, control is transferred to a step 308. If it was neither a down nor an up limit, control is transferred to a step 310. In the step 306, the position is set as the down limit value and a window flag is set. The operation state is set as down limit. In a step 308, the position is set as up, the window flag is set and the operation state is set as up limit. In the step 310, the position is set as outside the normal range, 6 inches below the secondary up limit. The operation state is set as stopped. Control is transferred from any of steps 306, 308 and 310 to a step 312 where a stored simulated motor temperature is read from the non-volatile memory 88. The temperature of a printed circuit board positioned within the head unit is read from the temperature sensor 120 which is supplied over a line 120a to the microcontroller. In order to read the PC board temperature, a pin P20 of the microprocessor 84 is driven high, causing a high potential to appear on a line 120b which supplies a current through the RTD sensor 120 to a comparator 120c. A capacitor 120d connected to the comparator and to the temperature sensor, is grounded and charges up. The other input terminal to the comparator has a voltage divider 120e connected to it to supply a reference voltage of about 2.5 volts. Thus, the microcontroller starts a timer running when it brings line 120b high and interrogates a line 120f to determine its state. The line 120f will be driven high when the temperature at the junction of the RTD 120 and the capacitor 120d exceeds 2.5 volts. Thus, the time that it takes to charge the capacitor through the resistance is indicative of the temperature within the head unit and, in this manner, the PC board temperature is read and if the temperature as read is greater than the temperature retrieved from the non-volatile memory, the temperature read from the PC board is then stored as the motor temperature. In a step 314, constants related to the receipt and processing of the demodulated signal on the line 82 are initialized. In a step 316, a test is made to determine whether the learn switch 39b had been activated within the last 30 seconds. If it has not, control is transferred back to the step 314. In a step 318, a test is made to determine whether the command switch debounce timer has expired. If it has, control is transferred to a step 320. If it is not, control is transferred back to the step 314. In the step 320, the learn limit cycle is begun as will be discussed in more detail as to FIGS. 6A through 6G. The main routine effectively has a number of interrupt routines coupled to it. In the event that a falling edge is detected on the line 112 from the tachometer, an interrupt routine related to the tachometer is serviced in the step 322. A timer interrupt occurs every 0.5 millisecond in a step 324 as shown in FIGS. 7A through 7B. The obstacle detector 90 generates a pulse every 10 milliseconds during the time when the beam from the infrared emitter 42 has not been interrupted either by the pass point system 49 or by an obstacle, in a step 326 following which the obstacle detector timer is cleared in a step 328. As shown in FIGS. 10A through 10C, operation of the switch biasing module 96 is controlled over the lines 100 by the microcontroller 84. The microcontroller 84, in the step 340, tests to determine whether an RS232 digital communications mode has been set. If it has, control is transferred to a step 342, as shown in FIG. 10C, testing whether data is stored in an output buffer to be output from the microcontroller 84. If it is, control is transferred to a step 344 outputting the next bit, which may include a start bit, from the output buffer and control is then transferred back to the main routine. In the event that there is no data in the data buffer, control is transferred to the step 346, testing whether data is being received over lines 100. If it is being received, control is transferred to a step 348 to receive the next bit into the input buffer and the routine is then exited. If not, control is transferred to a step 350. In the step 350, a test is made to determine whether a start bit for RS232 signalling has been received. If it has not, control is transferred to a return step 352. If it has, control is transferred to a step 354 in which a flag is set indicating that the start bit has been received and the routine is exited. As shown in FIG. 10A, if the response to the decision block 340 is no, control is transferred to a decision step 360. The switch status counter is incremented and then a test is determined as to whether the contents of the counter are 29. If the switch counter is 29, control is transferred to a step 362 causing the counter to be zeroed. If the counter is not 29, control is transferred to a step 364, testing for whether the switch status is equal to zero. If the switch status is equal to zero, control is transferred to a step 366. In a step 366, a current source transistor 368, shown in FIG. 11, is switched on, drawing current through resistors 370 and 372 and feeding current out through a line 39a connected thereto to the switch module 39 and, more specifically, to a resistor 380, a 0.10 microfarad capacitor 382, a 1 microfarad capacitor 384, a 10 microfarad capacitor 386 and a switch terminal 388. The switch 39e is coupled to the switch terminal 388. The switch 39d may be selectively coupled to the capacitor 386. The switch 39b may be selectively coupled to the capacitor 384. The switch 39c may be selectively coupled to the capacitor 382. A light emitting diode 392 is connected to the resistor 380. Current flows through the resistor 380 and the light emitting diode 392 back to another one of the lines 39a and through a field effect transistor 398 to ground. In step 402, the sense input on a line 100 coupled to the transistor 398 is tested to determine whether the input is high. If the input is high immediately, that is indicative of the fact that switches 39b through 39e are all open and in a step 404, debounce timers are decremented for all switches and a got switch flag is set and the routine is exited in the event that the test of step 402 is negative. Control is then transferred to a step 406 testing after 10 microseconds if the sense in output on the line 100 connected to the field effect transistor 398 is high, which would be indicative of the switch 39c having been closed. If it is high, step 408 indicates the worklight timer is incremented, all other switch timers are decremented, the got switch flag is set and the routine is exited. In the event that the decision in step 406 is in the negative, control is transferred to a step 410 and the routine is exited. In the event that the decision from step 364 is in the negative, control is transferred to a step 412 wherein the switch status is tested as to whether it is equal to one. If it is, control is transferred to a step 414 testing whether the sensed input on the line 100 connected to the field effect transistor is high. If it is, control is transferred to step 416 to determine if the got switch flag is set. If it is, control is transferred to a step where the learn switch debouncer is incremented, all other switch counters are decremented, the got switch flag is set and the routine is exited. In the event that the answer to step 414 or 416 is in the negative, control is transferred to a return step 420. In the event that the answer to step 412 is in the negative, control is transferred to a step 422, as shown in FIG. 10B. A test is made as to whether the switch status is equal to 10. If it is, control is transferred to a step 424 where the sense out input is tested as high. Thus, the charging rate for the capacitors which, in effect, is sensed on the line 100 connected to the field effect transistor 398 which is coupled to ground, is indicative of which of the switches is closed because the switch 39c has a capacitor that charges at 10 times the rate of the capacitor 384 connected to 39b and 100 times the rate of the capacitor 386 selectively couplable to switch 39d. After the switch measurement has been made, the transistor 368 is switched non-conducting by the line 368b and the field effect transistor 398 is switched non-conducting by a line 450 connected to its gate. A transistor 462, coupled via a resistor 464 to a line 466, is switched on, biasing a transistor 468 on, causing current to flow through a diagnostic light emitting diode 470 to a field effect transistor 472 which is switched on via a voltage on a line 474. In addition, the capacitors 386, 384 and 382, which may have been charged are discharged through the field effect transistor 472. In order to perform all of the switching functions after the step 424 has been executed, control is transferred to a step 510 testing whether the got switch flag has been cleared. If it has, control is transferred to a step 512 in which the command timer is incremented and all other timers are decremented and the got switch flag is set and the routine is exited. If the got switch flag has not been cleared as detected in the step 510, the routine is exited in the step 514. In the event that the sense input is measured as being high in the step 424, control is transferred to a step 516 where the vacation or lock flag counter is incremented and all other counters are decremented. The got switch flag is set and the routine is exited. In the event that the switch status equal 10 test in the step 422 is indicated to be no, control is then transferred to a step 520 testing whether the switch status is 11. If the switch status is 11, indicating that the routine has been swept through 11 times, control is transferred to a step 522 in which the field effect transistors 398 and 472 are both switched on, providing ground pads on both sides of the capacitors causing the capacitors to discharge and the routine is then exited. In the event that the step 520 test is negative, control is transferred to a step 524 testing whether the routine has been executed 15 times. If it has, control is transferred to a step 526 to determine if that the bit which controls the status of light emitting diode 470, the diagnostic light emitting diode, has been set. If it has not been set, control is transferred to a step 528 wherein both transistors 368 and 468 are switched on and both the field effect transistors 398 and 472 are switched off. In order to test for short circuits between the source and drain electrodes of the field effect transistors 398 and 472 which might cause false operation signals to be supplied on the lines 100 to the microcontroller 84, resulting in inadvertent operation of the electric motor. The routine is then exited. In the event that the test in step 526 indicates that the diagnostic LED bit has been set, control is transferred to a step 530. In the step 530, the transistors 468 and 472 are switched on allowing current to flow through the diagnostic LED 470. In the event that the test in step 524 is negative, a test is made in a step 532 as to whether the routine has been executed 26 times. If it has not, the routine is exited in a step 534. If it has, both of the field effect transistors 398 and 372 are switched on to connect all of the capacitors to ground to discharge the capacitors and the routine is exited. As shown in FIGS. 7A and 7B, when the timer interrupt occurs as in step 324, control is transferred to a step 550 shown in FIG. 7A wherein a test is made to determine whether a 2 millisecond timer has expired. If it has not, control is transferred to a step 552 determining whether a 500 millisecond timer has expired. If the 500 millisecond timer has expired, control is transferred to a step 554 testing whether power has been switched on through the relay logic 104 to the electric motor 106. If the motor has been switched on, control is transferred to a step 556 testing whether the motor is stalled, as indicated by the motor power having been switched on and by the fact that pulses are not coming through on the line 112 from the tachometer 110. In the event that the motor has stalled, control is transferred to a step 558. In the step 558 the existing motor temperature indication, as stored in one of the registers of the microcontroller 84, has added to it a constant which is related to a motor characteristic which is added in when the motor is indicated to be stalled. In the event that the response to the step 556 is in the negative, indicating that the motor is not stalled, control is transferred to a step 560 wherein the motor temperature is updated by adding a running motor constant to the motor temperature. In the event that the response to the test in step 554 is in the negative, indicating that motor power is not on and that heat is leaking out of the motor so that the temperature will be dropping, the new motor temperature is assigned as being equal to the old motor temperature, less the quantity of the old motor temperature, minus the ambient temperature measured from the RTD probe 120, the whole difference multiplied by a thermal decay fraction which is a number. All of steps 558, 560 and 562 exit to a step 564 which test as to whether a 15 minute timer has timed out. If the timer has timed out, control is transferred to a step 566 causing the current, or updated motor temperature, to be stored in a non-volatile memory 88. If the 15 minute timer has not been timed out, control is transferred to a step 568, as shown in FIG. 7B. Step 566 also exits to step 568. A test is made in the step 568 to determine whether a obstacle detector interrupt has come in via step 326 causing the obstacle detector timer to have been cleared. If it has not, the period will be greater than 12 milliseconds, indicating that the obstacle detector beam has been blocked. If the obstacle detector beam, in fact, has been blocked, control is transferred to a step 570 to set the obstacle detector flag. In the event that the response to step 568 is in the negative, the obstacle detector flag is cleared in the step 572 and control is transferred to a step 574. All operational timers, including radio timers and the like are incremented and the routine is exited. In the event that the 2 millisecond timer tested for in the step 550 has expired, control is transferred to a step 576 which calls a motor operation routine. Following execution of the motor operation routine, control is transferred to the step 552. When the motor operation routine is called, as shown in FIG. 8A, a test is made in a step 580 to determine the status of the motor operation state variable which may indicate that the up limit has been reached. If the up limit or the down limit have been reached, the motor is causing the door to travel up or down, the door has stopped in mid-travel or an auto-reverse delay indicating that the motor has stopped in mid-travel and will be switching into up travel shortly. In the event that there is an auto-reverse delay, control is transferred to a step 582, when a test is made for a command from one of the radio transmitters or from the wall control unit and, if so, the state of the motor is set indicating that the motor has stopped in mid-travel. Control is then transferred to a step 584 in which 0.50 second timer is tested to determine whether it has expired. If it has, the state is set to the up travel state following which the routine is exited in the step 586. In the event that the operation state is in the up travel state, as tested for in step 580, control is transferred to a step 588 testing for a command from a radio or wall control and if the command is received, the motor operational state is changed to stop in mid-travel. Control is transferred to a step 590. If the force period indicated is longer than that stored in an up array location, indicated by the position of the motor. The state of the door is indicated as stopped in mid-travel. Control is then transferred to a step 592 testing whether the current position of the door is at the up limit, then the state of the door is set as being at the up limit and control is transferred to a step 594 causing the routine to be exited, as shown in FIG. 8B. In the event that the operational state tested for in the step 580 is indicated to be at the up limit, control is transferred to a step 596 which tests for a command from the radio or wall control unit and a test is made to determine whether the motor temperature is below a set point for the down travel motor temperature threshold. The state is set as being a down travel state. If the temperature value exceeds the threshold or set point temperature value, an output diagnostic flag is set for providing an output indication in another routine. Control is then transferred to a step 598, causing the routine to be exited. In the event that the down travel limit has been reached, control is transferred to a step 600 testing for whether a command has come in from the radio or wall control and, if it has, the state is set as auto-reverse and the auto-reverse timer is cleared. Control is then transferred to a step 602 testing whether the force period, as indicated, is longer than the force period stored in the down travel array for the current position of the door. Auto-reverse is then entered at step 582 on a later iteration of the routine. Control is transferred to a step 604 to test whether the position of the door is at the down limit position and the pass point detector has already indicated that the door has swept the passed the pass point, the state is set as a down limit state and control is transferred to a step 606 testing for whether the door position is at the down limit position and testing for whether the pass point has been detected. If the pass point has not been detected, the motor operational state is set to auto-reverse, causing auto-reverse to be entered in a later routine and control is transferred to a step 608, exiting the main routine. In the event that the block 580 indicates that the door is at the down limit, control is transferred to a step 610, testing for a command from the radio or wall control and testing the current motor temperature. If the current motor temperature is below the up travel motor temperature threshold, then the motor state variable is set as equal to up travel. If the temperature is above the threshold or set point temperature, a diagnostic code flag is then set for later diagnostic output and control is transferred to a return step 612. In the event that the motor operational state is indicated as being stopped in mid-travel, control is transferred to a step 614 which tests for a radio or wall control command and tests the motor temperature value to determine whether it is above or below a down travel motor temperature threshold. If the motor temperature is above the travel threshold, then the door is left stopped in mid-travel and the routine is returned from in step 616. In the event that the learn switch has been activated as tested for in step 316 and the command switch is being held down as indicated by the positive result from the step 318, the learn limit cycle is entered in step 320 and transfers control to a step 630, as shown in FIG. 6A, in step 630, the maximum force is set to a minimum value from which it can later be incremented, if necessary. The motor up and motor down controllers in the relay logic 104 are disabled. The relay logic 104 includes an NPN transistor 700 coupled to line 76 to receive 24 to 28 volts therefrom via a coil 702 of a relay 704 having relay contacts 706. A transistor 710 coupled to the microcontroller is also coupled to line 76 via a relay coil 714 and together comprise an up relay 718 which is connected via a lead 720 to the electric motor 106. A down transistor 730 is coupled via a coil 732 to the power supply 76. The down relay 732 has an armature 734 associated with it and is connected to the motor to drive it down. Respective diodes 740 and 742 are connected across coils 714 and 732 to provide protection when the transistors 710 and 730 are switched off. In the step 632, both the transistors 710 and 730 are switched off, interrupting either up motor power or down motor power to the electric motor 106 and the microcontroller delays for 0.50 second. Control is then transferred to a step 634, causing the relay 704 to be switched on, delivering power to an electric light or worklight 750 associated with the head unit. The up motor relay 716 is switched on. A 1 second timer is also started which inhibits testing of force limits due to the inertia of the door as it begins moving. Control is then transferred to a step 636, testing for whether the 1 second timer has timed out and testing for whether the force period is longer than the force limit setting. If both conditions have occurred, control is transferred to a step 640 as shown in FIG. 6B. If either the 1 second timer has not timed out or the force period is not longer than the force limit setting, control is transferred to a step 638 which tests whether the command switch is still being held down. If it is, control is transferred back to step 636. If it is not, control is transferred to the step 640. In step 640, both the up transistor 710 and the down transistor 730 are causing both the up motor and down motor command from the relay logic to be interrupted and a delay of 0.50 second is taken and the position counter is cleared. Control is then transferred to a step 640 in which the transistor 730 is commanded to switch on, starting the motor moving down and the 1 second force ignore timer is started running. A test is made in a step 642 to determine whether the command switch has been activated again. If it has, the force limit setting is increased in a step 644 following which control is then transferred back to the step 632. If the command switch is not being held down, control is then transferred to a step 646, testing whether the 1 second force ignore timer has timed out. The last 32 rpm pulses indicative of the force are ignored and a force period from the previous pulse is accepted as the down force. Control is then transferred to a step 648 and a test is made to determine whether the movable barrier is at the pass point as indicated by the pass point detector 49 interacting with the optical detector 46. Control is then transferred to a step 650. The position counter is complemented and the complemented value is stored as the up limit following which the position counter is cleared and a pass point flag is set. Control is then transferred back to the step 642. In the event that the result of the test in step 648 is negative, control is transferred to a step 652 which tests whether the 1 second force delay timer has expired and whether the force period is greater than the force limit setting, indicating that the force has exceeded. If both of those conditions have occurred, control is transferred to a step 654 which tests whether the pass point flag has been set. If it has not been set, control is transferred to a step 656, wherein the position counter is complemented and the complemented value is saved as the up limit and the position counter is cleared. In the event that the pass point flag has been set, control is transferred to a step 658. In the event that the test in step 652 has been negative, control is transferred to a step 660 which tests the value of the obstacle reverse flag. If the obstacle reverse flag has not been set, control is transferred to the step 642 shown on FIG. 6B. If the flag has been set, control is transferred to the step 654. In a step 658, both transistors 710 and 730 are switched off interrupting up and down power from the relays to the electric motor 106 and halting the motor and the microcontroller 84 then delays for 0.50 second. Control is then transferred to a step 660. In step 660, the transistor 710 is switched on switching on the up relay causing the motor to be turned to drive the door upward and the 1 second force ignore timer is started. Control is transferred to a decision step 662 testing for whether the command switch is set. If the command switch is set, control is transferred back to the step 664 causing the force limit setting to be increased, following which control is transferred to the step 632, interrupting the motor outputs. If the command switch has not been set, control is transferred to the step 664 causing the maximum force from the 33rd previous reading to be saved as the up force, following which control is transferred to a decision block 666 which tests for whether the 1 second force ignore timer has expired and whether the force period is longer than the force limit setting. If both conditions are true, control is transferred to a step 668. If not, control is transferred to a step 670 which tests for whether the door position is at the up limit. If the door position is at the up limit, control is transferred to the step 668, switching off both of the motor outputs to halt the door and delaying for 0.50 second. If the position tested in step 670 is not at the upper limit, control is transferred back to the step 662. Following step 668 control is transferred to step 674, where the down output is turned on and the 1 second force ignore timer is started. Control is then transferred to the step 676 during which the command switch is tested. If the command switch is set, control is transferred back to the step 644 causing the force limit setting to be increased and ultimately to the step 632 which switches off the motor outputs and delays for 0.50 second. If the command switch has not been set, control is transferred to a step 678. If the position counter indicates that the door is presently at a point where a force transition normally occurs or where force settings are to change, and the 1 second force ignore timer has expired, the 33rd previous maximum force is stored and the down force array is filled with the last 33 force measurements. Control is then transferred to a step 680 which tests for whether the obstacle detector reverse flag has been set. If it has not been set, control is transferred to a step 682 which tests for whether the 1 second force ignore timer has expired and whether the force period is longer than the force limit setting. If both those conditions are true, control is transferred to a step 684 which tests for the pass point being set. If the pass point flag was not set, control is transferred to the step 688. In the event that the obstacle reverse flag is set, control is also transferred to the step 686, and then to 688. In the event that the decision block 682 is answered in the negative, control is transferred back to the step 676. If the pass point flag has been set as tested for in the step 684, control is transferred to the step 686 wherein the current door position is saved as the down limit position. In step 688, both the motor output transistors 710 and 730 are switched off, interrupting up and down power to the motor and a delay occurs for 0.50 second. Control is then transferred to the step 690 wherein the up transistor 710 is switched on, causing the up relay to be actuated, providing up power to the motor and the 1 second force ignore timer begins running. In the step 692, a test is made for whether the command has been set again. If it has, control is transferred back to the step 644, as shown in FIG. 6B, and following that to the step 632, as shown in FIG. 6A. If the command switch has not been set, control is transferred to the step 694 which tests for whether the position counter indicates that the door is at a sectional force transition point or barrier and the 1 second force ignore timer has expired. If both those conditions are true, the maximum force from the last sectional barrier is then loaded. Control is then transferred to a decision step 696 testing for whether the 1 second force ignore timer has timed out and whether the force period is indicated to be longer than the force period limit setting. If both of those conditions are true, control is then transferred to a step 698 causing the motor output transistors 710 and 730 to be switched off and all data is stored in the non-volatile memory 88 and the routine is exited. In the event that decision is indicated to be in the negative from the decision step 696, control is transferred to a step 697 which tests whether the door position is presently at the up limit position. If it is, control is then transferred to the step 698. If it is not, control is transferred to the step 692. In the event that the rpm interrupt step 322, as shown in FIG. 5B, is executed, control is then transferred to a step 800, as shown in FIG. 9A. In step 800, the time duration from the last rpm pulse from the tachometer 110 is measured and saved as a force period indication. Control is then transferred to a decision block. Control is transferred to the step 802, in which the operator state variable is tested. In the event that the operator state variable indicates that the operator is causing the door to travel down, the door is at the down limit or the door is in the auto-reverse mode, control is transferred to a step 804 causing the door position counter to be incremented. In the event that the door operator state indicates that the door is travelling upward, has reached its up limit or has stopped in mid-travel, control is transferred to a step 806 which causes the position counter to be decremented. Control is then transferred to a decision step 808 in which the pass point pattern testing flag is tested for whether it is set. If it is set, control is transferred to a step 810 which tests a timer to determine whether the maximum pattern time allotted by the system has expired. In the event that the pass point pattern testing flag is not set, control is transferred to a step 812, testing for whether the optical obstacle detector flag has been set. If it is not set, the routine is exited in a step 814. If the obstacle detector flag has been set, control is transferred to a step 816 wherein the pattern testing flag is set and the routine is exited. In the event that the maximum pattern time has timed out. As tested for in the step 810, control is transferred to a step 820 wherein the optical reverse flag is set and the routine is exited. In the maximum pattern time has not expired, a test is made in a step 822 for whether the microcontroller has sensed from the obstacle detector that the beam has been blocked open within a correct timing sequence indicative of the pass point detection system. If it has not, the routine is exited in a step 824. If it has, control is transferred to a step 826. Testing for whether a window flag has been set. As to whether the rough position of the door would indicate that the pass point should have been encountered. If the window flag has been set, control is transferred to a step 828, testing for whether the position is within the window flag position. If it has, control is transferred to a step 832, causing the position counter to be cleared or renormalized or zeroed, setting the window flag and set a flag indicating that the pass point has been found, following which the routine is exited. In the event that the position is not within the window as tested for in step 828, the obstacle reverse flag is set in a step 830 and the routine is exited. In the event that the test made in step 326 indicates that the window flag has not been set, control is then transferred directly to the step 832. While there has been illustrated and described a particular embodiment of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.

A movable barrier operator includes a wall control switch module having a learn switch thereon. The switch module is connectable to a control unit positioned in a head of a garage movable barrier operator. The head unit also contains an electric motor which is connected to a transmission for opening and closing a movable barrier such as a garage door. The switch module includes a plurality of switches coupled to capacitors which, when closed, have varying charge and discharge times to enable which switch has been closed. The control unit includes an automatic force incrementing system for adjusting the maximal opening and closing force to be placed upon the movable barrier during a learn operation. Likewise, end of travel limits can also be set during a learn operation upon installation of the unit. The movable barrier operator also includes an ambient temperature sensor which is used to derive a motor temperature signal, which motor temperature signal is measured and is used to inhibit motor operation when further motor operation exceeds or is about to exceed set point temperature limits.

BACKGROUND OF THE INVENTION The present invention relates to a free-piston engine having a fluid pressure unit according to the preamble of claim 1. In a known free-piston engine having a hydraulic unit (see U.S. Pat. No. 3,606,591), a second chamber portion of a second chamber is connected to the compression pressure accumulator through a connecting channel having a two-way valve. A compression stroke starts if a two-way switch is switched from the closed position to an open position. During the first part of the compression stroke hydraulic liquid flows through said two-way valve until, in a second part of the compression stroke, a connecting channel of a first chamber portion of the second chamber takes up the main part of the liquid flow from the compression pressure accumulator. In this prior art piston engine, very high and also conflicting demands are made upon the two-way valve. Then the two-way valve should have a very short switching time, ca. 1 ms, on the one hand requiring a small valve, and the two-way valve should have a relatively large flow capacity on the other hand in order to restrict the loss during the first part of the compression stroke. It is hardly possible to comply with these high and conflicting requirements so that in the present free-piston engines the efficiency is adversely affected by the loss of energy in the two-way valve, while the power of the engine is restricted by the slowness of the two-way valve. It is an object of the invention to provide a free-piston engine having a fluid pressure unit in which said problem is solved in an effective way. SUMMARY OF THE INVENTION According to the invention, only pressure means, for instance a two-way valve connected to the compression pressure accumulator or an independent pulsating small pump, are required to effect a very slight movement of the plunger-shaped piston extension to cause the passage means in the plunger-shaped piston extension to be opened by the closure element whereafter the passage means take over the task of the pressure means. Due to this feature the pressure means is only required to deliver a small amount of hydraulic liquid without involving a great loss of energy. As a result, it is possible to select a very small and quick valve having a small slowness for the two-way valve. Generally speaking, the passage means in the plunger-shaped piston extension can be selected efficiently big to cause a low flow resistance reducing the loss of energy during the flow therethrough. Consequently, the present restrictions to the power of a free-piston engine by the two-way valve is broken down by the invention. The particular valve according to the invention may of course also be used for other functions. Preferably, there are provided means acting such upon the closure element that when the piston springs back at the end of the expansion stroke the closure element follows the piston and continues to close the passage means, but when the compression stroke starts the closure element opening the passage means. BRIEF DESCRIPTION OF THE DRAWINGS The invention will hereafter be elucidated with reference to the drawing showing embodiments of a free-piston engine having hydraulic unit by way of example. FIG. 1 shows a scheme, partly as longitudinal sectional view of the free-piston engine having a hydraulic unit. FIG. 2 is an enlarged longitudinal sectional view of a part of the hydraulic unit of FIG. 1 illustrating the actual structural proportions of the exemplary embodiment. FIG. 3-8 show the operation of the hydraulic unit with the help of different working positions of a part of an alternative embodiment of the hydraulic unit according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an exemplary embodiment of a free-piston engine comprising a cylinder 1 and a movable piston 2 arranged therein. This piston 2 borders one side of the combustion room 3 and is movable between a first position or bottom dead centre in which the volume of the combustion room 3 is at a maximum, and a second position or top dead centre in which the volume of the combustion room 3 is at a minimum. To the combustion room connects an air inlet. 4 and a combustion gas outlet 5. In a cylinder head 6 bordering the combustion room 3 on the other side there is provided an injector 7 for injecting fuel, such as diesel oil, into the combustion room 3. During the compression stroke of the piston 2, that is when the piston 2 is displaced from the bottom dead centre to the top dead centre, air supplied to the combustion room 3 through the air inlet 4 is compressed, then liquid fuel is injected into the combustion room 3 through the injector 7, which then comes to spontaneous combustion under influence of pressure and temperature in the combustion room 3, which leads to expansion of the fuel-air mixture in the combustion room 3 causing the piston to make an expansion stroke towards the bottom dead centre. Of course, it is also possible that the engine operates according to another principle instead of the diesel principle, for example by means of spark ignition. To convert mechanical energy rendered to the piston 2 during the expansion of the fuel-air mixture into hydraulic energy and to convert hydraulic energy into a movement of the piston to make a compression stroke, the piston 2 is equipped with a plunger-shaped piston extension 8. This plunger-shaped piston extension 8 includes, as seen from the piston 2, a first rod section 9, a first plunger section 10, a second rod section 11 and a second plunger section 12. The first plunger section 10 cooperates with a working section 13 of the hydraulic unit and, for this purpose, it is slidable within a first chamber 14. The first plunger section 10 comprises a first axial face 15 bordering a room 16 of the first chamber 15 such that the volume of the room 16 decreases during the expansion stroke of the piston 2. The working section 13 comprises a high pressure accumulator 17 communicating with a connection 18 of the high pressure side of a user, such as a hydrostatic drive for a vehicle. The room 16 of the first chamber 14 communicates with the high pressure accumulator 17 through a first discharge channel 19 having a non-return valve 20 and through a second discharge channel 21 having a further non-return valve 22. The first discharge channel 19 is only operative during the first part of the expansion stroke of the piston 2 and has a low flow resistance as well as the non-return valve 20. After a certain part of the expansion stroke of the piston 2, the first discharge channel 19 is closed by the circumferential wall of the first plunger section 10 and then discharge of hydraulic liquid from the room 16 of the first chamber 14 takes place only through the second discharge channel 21 including a quick non-return valve 22. The working section 13 of the hydraulic unit further includes a low pressure accumulator 23 communicating with a connection 24 of the low pressure side of a user, such as the hydrostatic drive. The low pressure accumulator 23 communicates with the room 16 in the first chamber 14 through a first supply channel 25 having a non-return valve 26 and through a second supply channel 27 having a further non-return valve 28. The latter non-return valve 28 may be passed by through a by-pass line 29 including a two-way valve 30 switchable between a position in which it acts as a non-return valve and a position in which it enables a free discharge of hydraulic liquid from the room 16. The non-return valve 26 and the first supply channel 25 have a low flow resistance, while the non-return valve 28 in the second supply channel is of a quick closing type, for example being equipped with a heavy set back spring. In a first part of the compression stroke of the piston 2, a supply of hydraulic liquid from the low pressure accumulator 23 to the room 16 is possible only through the second supply channel 27, and in a second part of the compression stroke, the second supply channel 27 is opened by the circumferential wall of the first plunger section 10 and then hydraulic liquid may be supplied to the room 16 through the first supply channel 25. In the first chamber 14, on the other side of the first plunger section 10, there is a further room 31 which is preferably pressureless, for example communicates with the environment through the channel 32, in order to cause minimum losses during the reciprocating movement of the first plunger section 10. The second plunger section 12 cooperates with a compression section 33 and, for this purpose, moves within a second chamber 34 comprising a first chamber portion 35 having a diameter being equal to or, in this case, being greater than that of the second plunger section 12, and a second chamber portion 36 having a diameter selected such that the second plunger section 12 sealingly fits into it. The compression section 33 further includes a compression pressure accumulator 37 being in open communication with the first chamber portion 35 of the second chamber 34 through a first connecting channel 38 having a low flow resistance. A second connecting channel 39 extends between the second chamber portion 36 of the second chamber 34 and the compression pressure accumulator 37 and comprises a quick closing non-return valve 40 encountering a flow to the second chamber portion 36. In the second plunger section 12 and the second rod section 11 there is formed a passage 41, in this case consisting of an axial and joining radial bore and opening on one end into the first chamber portion 35 in a position right behind a second axial face 42 bordering the first chamber portion 25 of the second chamber when the piston 2 is in the bottom dead centre, and on the other hand opening in a third axial face 43 on the free end of the plunger-shaped piston extension, which borders the second chamber portion 36 of the second chamber 34 when the piston 2 is in the bottom dead centre. The passage 41 is closable by the conical tip 44 of a needle body 45 extending through the second chamber portion 36 and coming out through a guiding and sealing bore in a third chamber 46 where the needle body 45 is connected to a plunger member 47 fitting sealingly in the third chamber 46. A compression spring in the form of a helical spring 47A loads the plunger member 47 and the needle body 45 in a direction opposite to the direction of the expansion stroke of the piston 2 and the plunger-shaped piston extension 8. The plunger member 47, on the side of the needle body 45, borders a room 48 to which a supply channel 49 connects, which supply channel 49 connecting to the compression pressure accumulator 37 through a two-way valve 50, but which could also be provided with a separate pulsating pump element. On the other hand, the room 48 of the third chamber 46 is connected by a connecting channel 51 to a connecting channel 52 extending between the low pressure accumulator 23 and the second chamber portion 36 of the second chamber 34. Between the connection of the connecting channel 51 to the connecting channel 52 and the second chamber portion 36 is a quick closing non-return valve 53 resisting a flow of hydraulic liquid from the second chamber portion 36, and between the low pressure accumulator 23 and the connection of the connecting channel 51 to the connecting channel 52 there is a non-return valve 54 preventing a flow to the low pressure accumulator 23. The non-return valve 54 is of a slower closing type than the quick closing non-return valve 40 in the second connecting channel 39, the meaning of which will be explained later on. On the side of the helical spring 47A, the plunger member 47 of the needle body 45 further borders a second room 55 in the third chamber 46, which second room 55 is in open communication with the compression pressure accumulator 37 through a connecting channel 56. FIG. 2 shows more details of a portion of the hydraulic unit of FIG. 1, in-which the structural proportions of the needle body 45 can be recognized. It is shown for instance that the diameter of the plunger member 47 is only very slightly (5%) greater than that of the needle body 45 in order to keep the volume of the room 48 to a minimum so as to minimize the frequency retardation as a result of the oil volume. The tip 44 is truncated and the chamfered portion is slightly convex to facilitate the location and seal thereof onto the seat of the passage 41 in the plunger section 12. The needle body 51 has a self locating straight guide to obtain a light and smooth running of the needle body 45. The normal operation of the free-piston engine having a hydraulic unit, and in particular the compression section thereof, is as follows. In an expansion stroke of the piston 2 as a consequence of the expansion of the fuel-air mixture in the combustion room 3 of the cylinder 1, ignited by spontaneous combustion, hydraulic fluid is discharged by the first plunger section 10 from the room 16 of the first chamber 14 to the high pressure accumulator 17, first through the first discharge channel 19 having a low flow resistance and then through the second discharge channel 21. In this manner, pressure is built up in the high pressure accumulator 17 which can be used by the user connected to the connection 18. During said expansion stroke of the piston 2, the needle body 45 and the plunger member 47 are maximally pushed away by the helical spring 47A so that the needle body 45 together with its conical tip 44 projects into the second chamber portion and eventually into the first chamber portion 35 of the second chamber 34. Upon approach of the plunger-shaped piston extension 8, the second plunger section 12 of the plunger-shaped piston extension 8, the speed of which is decreased in the meantime, comes in contact with the conical tip 44 of the needle body 45, the conical tip 44 penetrating into the passage 41 and, as a result, closing off the passage 41 in the second plunger section 12. The hydraulic liquid in the second chamber 34, which was discharged mainly through the first connecting channel 38 to the compression pressure accumulator 37 in the first part of the expansion stroke of the piston 2, is now conducted only through the second connecting channel 39 and through the quick closing non-return valve 40 to the compression pressure accumulator 37 after the second plunger section 12 has entered the second chamber portion 36 of the second chamber 34. If the energy in the piston 2 coming from the expansion in the combustion room 3 is fully absorbed by the hydraulic liquid, the piston 2 and hence also the plunger-shaped piston extension 8 comes to rest. Both the non-return valve 22 in the second discharge channel 21 of the working section 13 and the non-return valve 40 in the second connecting channel 39 of the compression section 33 should then close very quickly so that hydraulic liquid in the room 16 and the second chamber portion 36, respectively, cannot flow back. The hydraulic liquid in the working section 13 and the compression section 33 is subjected, however, to a high pressure and hydraulic liquid in the room 16, the second chamber portion 36, the second discharge channel 21 and the second connecting channel 39 is inclined to expand causing the piston to spring back with a very high acceleration until the retaining force on the plunger-shaped piston extension 8, caused by the compression pressure in the first chamber portion 35 of the second chamber 34 acting upon the second axial face 42, is in balance with the opposite forces on the plunger-shaped piston extension 8. The piston body 45 should follow this very quick rebound of the piston 2 in order to keep the passage 41 in the second plunger section 12 closed with its conical tip 44 because otherwise hydraulic liquid can flow from the first chamber portion 35 through the passage 41 to the second chamber portion 36 and thereby starting a new compression stroke. Allowing the needle body 45 to follow the piston 2 is effected because the non-return valve 54, through which hydraulic liquid is sucked-in from the low pressure accumulator 23 during the movement of the plunger member 47 of the needle body 45 at the end of the expansion stroke, closes slower than the non-return valve 40 in the second connecting chamber 39. Due to this quick closure of the non-return valve 40, the pressure in the second chamber portion 36 drops quickly, whereby first the pressure in the room 48 remains as low as the pressure in the low pressure accumulator 23, and after closing the non-return valve 54 the pressure in the second chamber portion 36 is decreased in the meantime so that any pressure in the room 48 can be relieved through the non-return valve 53. In this manner, the pressure in the room 48 remains low so that there is no large retaining force on the plunger member 47 of the needle body 54 when the piston 2 and the plunger-shaped piston extension 8 springs back from the bottom dead centre, whereby the needle body 45 is allowed to follow the movement of the plunger-shaped piston extension as a result of the force of the helical spring 47A and the compression pressure on the plunger member 47 and hence the passage 41 in the plunger-shaped piston extension 8 remains closed by the conical tip 44 of the needle body 45 so that the piston 2 can be retained in its bottom dead centre. Only if a new compression and expansion stroke of the piston 2 is required, the piston is caused to move again. When the piston 2 springs back in the neighbourhood of the bottom dead centre, hydraulic liquid may leak from the second chamber portion 36 of the second chamber 34 past the needle body 45 to the room 48 of the third chamber. The volume of this room 48 of the second chamber 46 and the channels connected thereto are sufficiently big to prevent in that case a too large pressure rise which would disturb the function of the needle body 45. To start a new compression stroke of the piston 2, the two-way valve 50 is switched over thereby allowing hydraulic liquid to flow from the compression pressure accumulator 37 through a discharge channel 49 to the room 48 in the third chamber 46 and then through the connecting channel 51, the non-return valve 43 and the connecting channel 52 to the second chamber portion 36 of the second chamber 34. This pressure pulse pushes the second plunger section 12 and hence the whole plunger-shaped piston extension 8 and the piston 2 away by a load onto the third axial face 43, while the needle body 45 cannot follow the plunger-shaped piston extension 8 due to its slowness and the insufficient spring force of the spring 47A. Already after a very slight displacement of the second plunger section 12, the passage 41 is opened thereby allowing hydraulic liquid to flow from the first chamber portion 35 to the second chamber portion 36 disturbing the balance of forces and shooting away the piston. Since the passage 41 has a relatively large diameter, it also has a low flow resistance so that a quick and highly efficient compression stroke may be made. After the piston 2 has left, the needle body 45 will also be urged to its extreme position by the helical spring 47A, in which it is able to receive the plunger-shaped piston extension 8 again in the next expansion stroke. According to the invention, no high demands are made anymore upon the two-way valve 50 for starting the compression stroke of the piston concerning the low flow resistance because this two-way valve 50 is flowed through only during a very small part of the compression stroke of the piston 2 whereafter the passage 41 in the plunger-shaped piston extension 8 takes over this task. In FIG. 1 it is further shown that the hydraulic unit comprises an auxiliary means used for bringing the piston 2 to the bottom dead centre when the free piston engine is started or when it is restarted after a so called "misfiring" in which the fuel-air mixture in the combustion room 3 is not ignited and as a result thereof the piston 2 is not driven up to its bottom dead centre. This auxiliary means consists of a room 58 in the first chamber portion 35 of the second chamber, which room 58 is bordered by an axial face 59 of a ring-shaped element 60 engaging sealingly and slidably on the second rod section 11 of the plunger-shaped piston extension 8 on the one hand and engaging sealingly on the circumferential wall of the first chamber portion 35 of the second chamber 34 on the other hand. To the room 58 connects an auxiliary channel 61 in which a bi-directional pump 62 is incorporated and which connects to the compression pressure accumulator 37. During the normal operation of the free-piston engine, the ring-shaped element 60 is substantially stationary in the position shown, in which it serves as it were as a stationary wall of the first chamber 35 and in which the second rod section 11 reciprocates through the ring-shaped element 60. Upon actuation of the auxiliary means, the two-way valve 30 in the by-pass line 29 of the working section 13 of the hydraulic unit is switched so that the high pressure in the room 16 falls away. Then the bi-directional pump 62 is driven such that the room 58 is pressurized so as to displace the ring-shaped element 60 in a direction towards the bottom dead centre of the piston 2. At a certain moment, the ring-shaped element 60 will abut against the second axial face 42 formed on the second plunger-section 12 so that the ring-shaped element 16 will carry along the plunger-shaped piston extension 8 and hence the piston 2 to the desired position. Before a new compression stroke is made, the ring-shaped element 60 is brought back to its initial position by driving the bi-directional pump 62 in the other direction so that the ring-shaped element 60 can return to its initial position. By using this ring-shaped element 60, the room 58 is used only if it is necessary and no continuous filling and emptying the room 58 takes place which would have been the case if the ring-shaped element 60 would be fixed to the plunger-shaped piston extension. FIG. 3-8 show an alternative embodiment of the compression section of the hydraulic unit according to the invention, which is particularly intended to facilitate the start of the compression stroke of the piston 8. The two-way valve 50, comprising a parallel non-return valve 63, is now connected to a pressure booster 64. This pressure booster comprises a plunger 65 having axial faces 66, 67 and 68 bordering rooms 69, 70 and 71, respectively. The plunger 65 is biassed by a spring 72 in a direction to a position in which the room 69 connected to the two-way valve 56 is at a minimum. The room 71 is stepped and the diameter of the smallest part substantially equals the diameter of the corresponding axial face 68 so that this axial face 68 of the plunger 65 can separate both portions of the room 71. The room 70 of the pressure booster 64 communicates with the second chamber portion 36 adjacent the axial face 43 of the plunger-shaped piston extension 8. The portion of the room 71 of the pressure booster 64 having the greater diameter communicates on the one hand with the second chamber portion 36 through a non-return valve 73 and with the low pressure accumulator 23 through a non-return valve 74 on the other hand. The portion of the room 71 having a smaller diameter is in open communication with the room 48 for the plunger member 47 of the needle body 45. A second two-way valve 75 having a parallel non-return valve 76 is arranged in the connection between the compression pressure accumulator 37 and the second chamber portion 36. The operation of this alternative embodiment of the hydraulic unit will now be explained with reference to FIG. 3-8. FIG. 3 shows the position of the various parts when the piston 2 together with the plunger-shaped piston extension 8 has arrived near the end of the expansion stroke. The needle body 45 is urged into the extreme position by the spring 47A, while the plunger 65 is kept in its rest position by the spring 72. The two-way valves 50 and 75 are closed. In FIG. 4 the plunger section 12 of the plunger-shaped piston extension 8 has arrived in the second chamber portion 36 and the plunger section 12 has come into engagement with the tip 44 of the needle body 45 closing off the passage 41 in the second plunger section 12. The needle body 45 and the plunger member 47 are carried along by the plunger-shaped piston extension 8 against the force of the helical spring 47A. As a result, the pressure in the room 48 in front of the plunger member 47 drops. Due to the open connection between the room 48 and the room 71 in the pressure booster 64 the pressure there also decreases to that of the low pressure accumulator 23. In FIG. 5, the plunger-shaped piston extension 8 has sprung back from an extreme position slightly to the stabilized bottom dead centre. This springing back of the second plunger section 12 in the second chamber portion 36 causes the pressure in the second chamber portion 36 to drop to substantially that of the low pressure accumulator 23. Due to the pressure differential over the plunger member 47 of the needle body 45 and due to the force of the helical spring 47A, the needle body 45 is enabled to follow the movement of the plunger-shaped piston extension 8 so that the passage 41 in the second plunger section 12 remains closed. FIG. 6 shows the start of the compression stroke of the piston 2, for which purpose the two-way valve 50 and in this exemplary embodiment also the two-way valve 75 are opened. Due to the opening of the two-way valve 50, pressure from the compression pressure accumulator 37 arrives in the room 69 of the pressure booster 64 and consequently also acts upon the axial face 66 of the plunger 65 thereof, whereby the plunger 65 is urged away against the force of the spring 72 such a distance that the portion of the room 71 having the smaller diameter is closed off by the axial face 68 so that the room 48 in front of the plunger member 47 of the needle body 45 is also closed causing a pressure built-up in the room 48. This pressure in the room 48 prevents a movement of the needle body 45. Due to the displacement of the plunger 65 of the pressure booster 64 the pressure in the room 70 and consequently in the second chamber portions 36 rises. Due to the second two-way valve 75, this pressure rise in the second chamber portion is substantially higher because the compression pressure is admitted into the second chamber portion 36. This assistance of the additional two-way valve 75 is not necessary in 95% of the frequence range, but for a small number of frequencies the two-way valve 75 may be used to obtain an easier control. FIG. 7 shows the position of the plunger-shaped piston extension 8 wherein it has started its compression stroke due to the pressure in the second chamber portion 36, while the needle body 45 remains stationary and is not able to follow the second plunger section 12 due to the pressure in the room 48 thereby opening the passage 41 and allowing hydraulic liquid to easily flow through the passage 41 having a low flow resistance to the second chamber portion 36 thereby forcing the plunger-shaped piston extension 8 to the top dead centre of the piston 2 with great speed by the pressure on the axial face 43. FIG. 8 finally shows a further position in which the plunger 65 of the pressure booster 46 is urged back to the initial position by the force of the spring 72. The needle body 45 will eventually be forced back to the position of FIG. 3 so that both members are ready again for the next expansion stroke of the piston 2 and the plunger-shaped piston extension 8. The invention is not restricted to the embodiment shown in the drawing and described before by way of example, which may be varied in different manners within the scope of the appended claims. For example, the invention can also be used for a free-piston engine having two opposed pistons bordering one combustion room. Furthermore, the pressure booster may be integrated in or near the needle body.

A free-piston engine having a fluid pressure unit, comprises a cylinder and a piston arranged therein. The piston is equipped with a plunger-shaped extension including a working section having a room bordered by a first axial face of the plunger-shaped extension and the volume of which is reduced when the piston makes an expansion stroke, and to which a discharge channel to a high pressure accumulator and a supply channel from a supply reservoir connects. The piston further includes a compression section including a chamber having a first chamber portion enclosed by a second axial face in the bottom dead center of the piston and a second chamber portion bordered by a third axial face. The first chamber section decreases at the start of the compression stroke of the piston, wherein the first chamber portion has an open connection with a compression accumulator through a first connecting channel and the second chamber portion unit is connected to the compression pressure accumulator through a second connecting channel and is connectable to a pressure device for starting the compression stroke, whereafter the first connecting channel is opened in order to exert pressure on the third axial face. The plunger-shaped extension includes a passage extending from the first to the second chamber portion in the bottom dead center of the piston. A resiliently supported and axially movable closure element extends within the second chamber portion that lies in the path of the passage in the third axial face and encloses the passage at the end of the expansion stroke of the piston and opens it at the start of the compression stroke.

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation application of the prior application Ser. No. 12/182,451 filed Jul. 30, 2008, now U.S. Pat. No. 8,329,948, which claims the benefit to U.S. Provisional Patent Application Serial No. 60/962,739 filed Jul. 31, 2007 , which are hereby incorporated herein by reference in their entirely. BACKGROUND OF THE INVENTION Aldehydes and ketones are valuable building blocks for chemical industry. Reductive amination is a fundamental chemistry process that dramatically expands the application of aldehydes and ketones by transforming them into amines. The Leuckart reaction is a unique one step method of reductive amination. It is a remarkably simple process that includes only two components: the carbonyl compound and formamide. The reaction is completed simply by heating the components at 160° C. to 185° C. for 6 to 25 hours [1]. The long processing time seemed to be the only shortcoming of the reaction. However, it is associated with a number of serious practical problems. First, the prolonged exposure of the reaction mixture to high temperatures inevitably leads to significant thermal decomposition of the components, and, consequently, to lower yields of the products and difficulties with their isolation and purification. Second, maintaining high temperatures for a long period of time means high consumption of energy and increasing production costs which make the Leuckart reaction unattractive to chemical industry. Third, long processing times per se are unattractive to fast paced modern synthetic applications, such as combinatorial chemistry and automated parallel synthesis. Thus, the Leuckart reaction as a unique one step method of reductive amination became almost completely abandoned in modern synthetic chemistry. Most of the current reductive amination procedures are currently performed as two step combinations of the separate amination and reduction reactions. These two step procedures can often take as much time as the traditional Leuckart reaction [2]. They are also quite expensive because they require either the use of custom complex hydrides, or precious metal catalysts and high pressure equipment. Their only advantage over the one step Leuckart reaction is that they are not accompanied by thermal decomposition and as a result produce cleaner products. Therefore, it is evident that there is a compelling need for a fast and inexpensive method of reductive amination of aldehydes and ketones equally attractive to industrial and laboratory practices. SUMMARY OF THE INVENTION An improved method for the synthesis of substituted formylamines via an accelerated Leuckart reaction. The method may also include an accelerated hydrolysis of the substituted formylamines to substituted amines. The accelerated Leuckart reaction is conducted by reacting formamide or N-alkylformamide, formic acid and an aldehyde or a ketone at a specific molar ratio and a specific temperature. The accelerated Leuckart reaction is completed within minutes or seconds instead of hours. The accelerated hydrolysis is conducted in the presence of a specific acid and a specific solvent at an elevated temperature. The accelerated hydrolysis is also completed within seconds. DETAILED DESCRIPTION OF INVENTION The improved method of reductive amination of aldehydes and ketones via an accelerated Leuckart reaction is an unanticipated discovery. The Leuckart reaction was first described in the XIX century, and since that time remained one of the slowest reactions in organic chemistry. Many attempts were made to improve the reaction by using various additives, most commonly formic acid. However, the only area of improvement appeared to be the yield of the product, not the processing time. In 1996 a significantly shorter reaction time of 30 minutes was achieved through the use of microwave heating [3]. However, the technique was successfully applied only to a very narrow group of compounds. In addition, the current technical solutions for microwave assisted synthesis do not allow for processing large-scale reactions and therefore cannot be used in industry. In the present invention using the Leuckart reaction it was unexpectedly discovered that the reaction time can be dramatically decreased by decreasing the concentration of the aldehyde or a ketone used in the reaction. Certain specific molar ratios of the aldehyde (ketone), formic acid, and formamide (alkylformamide) the reaction time can be reduced to 30 minutes or lower without the use of microwave assistance. Surprisingly it was found, that in many cases the reaction becomes instant, i.e. fully completed at the moment when it reaches the usual reaction temperature of 160-185° C. The accelerated Leuckart reaction is equally successful if it is conducted with conventional or microwave heating. The unique molar ratio of formamide (N-alkylformamide) to an aldehyde or a ketone is between 150:1 to 5:1 and most preferably between 100:1 to 10:1. The specific molar ratio of formamide (N-alkylformamide) to formic acid is between 20:1 to 6:1 and most preferably 10:1. The specific temperature of the accelerated Leuckart reaction is between 150-200° C., and most preferably 180-190° C., if the reaction is conducted in an open system. It was found that the specific temperature of the accelerated Leuckart reaction is between 150 to 250° C., most preferably 190-210° C., if the reaction is conducted in a sealed system. This accelerated Leuckart reaction can be successfully applied to the areas where the traditional Leuckart reaction was not successful. Specifically, it was believed that the Leuckart reaction does not work on substituted benzaldehydes, and that the substituted benzylamines cannot be obtained from the respective benzaldehydes via the Leuckart reaction [1]. Further the accelerated Leuckart reaction does work on substituted benzaldehydes and that practically any substituted benzylamine can be prepared via the accelerated Leuckart reaction. Specifically, it was found that the reductive amination of vanillin (4-hydroxy-3-methoxybenzaldehyde) can be completed instantly via the accelerated Leuckart reaction. Vanillylamine is an important industrial chemical that is used for the synthesis of safe natural painkillers, such as capsaicin and analogs. The new accelerated Leuckart reaction comprises the new method of the synthesis of vanillylamine. Further, it was also discovered that the accelerated Leuckart reaction can be successfully applied to α,β-unsaturated aldehydes and ketones, thus comprising a new method of obtaining substituted allylamines. The improved increased reaction rate prevents any substantial thermal deterioration of the reaction mixture. As a result, the filtrates obtained after the separation of the reaction products can be repeatedly used as solvents for the next rounds of the reaction. The accelerated Leuckart reaction allows for the recycling of the reaction filtrates thus leading to quantitative yields of the products and minimal amounts of wastes. As a complementary process, it was shown that substituted formylamines that are obtained as a result of the Leuckart reaction can be hydrolyzed to substituted amines via an accelerated (instant) hydrolysis. Normally, the hydrolysis step that follows the Leuckart reaction is a relatively slow step that takes about an hour. Surprisingly, in the presence of a specific solvent the hydrolysis step also becomes an instant procedure. As a result, the entire process of obtaining amines from aldehydes and ketones becomes a combination of two accelerated (instant) reactions, an accelerated (instant) Leuckart reaction and accelerated (instant) hydrolysis. The present invention is illustrated by the following examples herein. EXAMPLE 1 Reductive amination of vanillin (I) The multi-mode MARS 5 reaction system (CEM Corporation) with GreenChem reaction vessels was used for the synthesis of vanillylformamide (II). 1.52 g (10 mmol) of I, 20 ml of formamide, and 1 ml of formic acid were placed in the GreenChem reaction vessel. The GreenChem reaction vessel was placed into the MARS 5 reaction system and the reaction mixture was quickly heated to 200° C. The reaction mixture was kept at 200° C. for 3 minutes and then cooled to 100° C. The GreenChem reaction vessel was removed from the MARS 5 system, the residual pressure was released, and the reaction vessel was opened. TLC showed that the reaction was complete. The reaction mixture was diluted with 50 ml of water and extracted with ethyl acetate. The extract was dried with sodium sulfate and the solvent was evaporated. The residue was purified by column chromatography (silica gel, CH 2 Cl 2 :CH 3 OH 20:1 v/v) and yielded 1.37 g (75%) of N-vanillylformamide (II), m.p. 83.5° C. (benzene). 1 H NMR (D 6 -acetone): 8.21 s (1H, HC═O), 7.60 s (1H, NH), 7.55 br.s. (1H, OH), 6.93 s (1H, aromatic), 6.76 s (2H, aromatic), 4.32 d (2H, CH 2 ), 3.80 s (3H, CH 3 ). 13 C NMR (D 6 -acetone): 161.9 (C═O), 148.7, 147.1, 131.7, 121.6, 116.1, 112.6 (aromatic carbons), 56.6 (CH 3 ), 42.3 (CH 2 ). IR (neat crystals, ATR, cm −1 ): 3296 (NH), 3213 (OH), 1643 (C═O). C 9 H 11 NO 3 , calculated, %: C, 59.66; H, 6.12; N, 7.73. Found, %: C, 59.90, 59.89; H, 6.13, 6.12; N, 7.74, 7.73. The reaction was repeated with 4.56 g (30 mmol) of vanillin and a reaction time of 1 min. TLC showed that the reaction was complete. The reaction mixture was extracted and purified the same way producing 3.29 g (60%) of N-vanillylformamide (II). The reaction was repeated with 1.52 g (10 mmol) of vanillin and conventional heating at 190° C. for 1 minute. The reaction mixture was extracted and purified the same way producing 1.46 g (80%) of N-vanillylformamide (II). EXAMPLE 2 Instant reductive amination of 4-hydroxybenzaldehyde (III) 4-hydroxybenzaldehyde (1.22 g or 10 mmol), formamide (22.72 g or 20.03 mL) and formic acid (2.43 g or 2 mL) were placed into a 50 mL round bottom flask equipped with a thermometer, a reflux condenser, a magnetic stirrer and a heating mantle. The reaction mixture was heated to 189° C. The heating was immediately turned off; the reaction flask was quickly raised from the heating mantle and allowed to cool to room temperature. The TLC conducted on the cold reaction mixture confirmed that the reaction was complete. The reaction mixture was diluted with 50 ml of water and extracted with ethyl acetate. The extract was dried with sodium sulfate and the solvent was evaporated to produce 1.17 g (77.1%) of 4-hydroxybenzylformamide (IV). EXAMPLE 3 Reductive amination of 1-(2,4-dichlorophenyl)-4,4-dimethyl-1-propen-3-one (V) One g (3.9 mmol) of V, 2 ml of formic acid, and 20 ml of formamide were placed in a round bottom flask equipped with thermometer, reflux condenser, and a heating mantle. The reaction mixture was heated to 188-190° C. and maintained at this temperature for 10 minutes. The reaction mixture was left to cool to room temperature overnight. The precipitated crystals were separated by filtration, rinsed with water, and dried with vacuum, producing 70% of N-[1-(2,4-dichlorophenyl)-4,4-dimethyl-1-propen-3-yl]-formamide (VI). EXAMPLE 4 Reductive amination of benzophenone (VII) The reaction procedure for V was repeated with 5 g of benzophenone and the reaction time of 15 minutes. The reaction produced 95% of benzhydrylformamide (VIII) (isolated yield). EXAMPLE 5 Instant hydrolysis of N-[1-(2,4-dichlorophenyl)-4,4-dimethyl-1-propen-3-yl]formamide (VI) One g of VI, 10 ml of concentrated hydrochloric acid, and 10 ml of methanol were placed in the GreenChem reaction vessel. The GreenChem reaction vessel was placed into the MARS 5 reaction system and the reaction mixture was quickly heated to 120° C. The microwave heating was immediately turned off and the reaction mixture was quickly cooled to 60° C. The GreenChem reaction vessel was removed from the MARS 5 system, the residual pressure was released, and the reaction vessel was opened. TLC showed that the reaction was complete. The reaction mixture was cooled to room temperature; the precipitated crystals were separated by filtration. The filtrate was dried with vacuum and produced an additional amount of the product. The yield of N-[1-(2,4-dichlorophenyl)-4,4-dimethyl-1-propen-3-yl]-amine hydrochloride (IX) is quantitative. EXAMPLE 6 Instant hydrolysis of benzhydrylformamide (VIII) The reaction procedure for VI was repeated with 1 g of VIII and produced quantitative yield of benzhydrylamine hydrochloride (X). EXAMPLE 7 Instant hydrolysis of vanillylformamide (II) The reaction procedure for VI was repeated with 1 g of II and produced quantitative yield of vanillylamine hydrochloride (XI). EXAMPLE 8 Reductive amination of 2,4,6-trimethoxybenzaldehyde (XII) with recycling of the filtrate 1.96 g (10 mmol) of XII, 20 ml of formamide, and 2 ml of formic acid were placed in the GreenChem reaction vessel. The GreenChem reaction vessel was placed into the MARS-5 reaction system and the reaction mixture was quickly heated to 200° C. The reaction mixture was kept at 200° C. for 3 minutes and then cooled to 100° C. The GreenChem reaction vessel was removed from the MARS 5 system, the residual pressure was released, and the reaction vessel was opened. TLC showed that the reaction was complete. The reaction mixture was cooled to room temperature; the precipitated crystals were separated by filtration, rinsed with water and dried with vacuum. The filtrate was used as solvent in the next reaction. The reaction was repeated 10 times. The total of 9.6492 g of formic acid, and 34.5680 g of formamide were added to the reaction mixture over the ten cycles to compensate the losses. The total yield of 2,4,6-trimethoxybenzylformamide (XIII) is quantitative. Other Embodiments The description of the specific embodiments of the invention is presented for the purpose of illustration. It is not intended to be exhaustive nor to limit the scope of the invention to the specific forms described herein. Although the invention has been described with reference to several embodiments, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the claims. All patents, patent applications and publications referenced herein are hereby incorporated by reference. Other embodiments are within the claims.

An improved method for the synthesis of substituted formylamines and substituted amines via an accelerated Leuckart reaction. The Leuckart reaction is accelerated by reacting formamide or N-alkylformamide and formic acid with an aldehyde or a ketone at a preferred molar ratio that accelerates the reaction. The improved method is applicable to various substituted aldehydes and ketones, including substituted benzaldehydes. An accelerated method for the hydrolysis of substituted formylamines into substituted amines using acid or base and a solvent at an elevated temperature. The improved method is useful for the accelerated synthesis of agrochemicals and pharmaceuticals such as vanillylamine, amphetamine and its analogs, and formamide fungicides.

FIELD OF THE INVENTION [0001] The present invention relates to computer systems and, more particularly, to computer systems incorporating, for example, power or cooling management. BACKGROUND TO THE INVENTION [0002] Computers can be configured according to a myriad of configuration possibilities. These configurations encompass entry level configurations with almost no add-in cards in situ or a heavy, or fully loaded, configuration that might accommodate a significant number of PCI or AGP cards. Since each card can consume, up to 25 Watts or add to the power budget for the PCI bus, adding such cards can impose an increased load on the PSU, which has associated power delivery issues, and also increase the cooling requirements imposed on the cooling system of the computer system. [0003] The PCI SIG organisation introduced two pins, PRSNT [1:2], on each card to allow that card to signal to the motherboard, and, ultimately, the cooling system or power supply, its maximum power or cooling requirements. Using this information, the computer system can identify situations in which the PSU might be overloaded or adjust the cooling system to increase or reduce the effective cooling. The information provided by the two pins is fixed and time invariant. [0004] Therefore, assuming, for example, that the AGP card comprises a high power video processor that has a high power consumption only during computationally intensive 3-D video processing, which generates or results in a maximum power consumption of 25 W, the cooling system and the PSU of the computer system will, upon detecting such a high power video processor card, ensure that sufficient power is made available by the PSU and that sufficient cooling is provided for the video processor by the cooling system respectively. However, the power consumption of such a high power video processor is unlikely to reach a full 25 W in all situations but for actually performing such computationally intensive 3-D rendering or the like. Therefore, for example, when the computer system is being used to run a word processing application or is standing “idle”, the current video processing activities do not justify such a high level or onerous degree of cooling. There are other PCI cards such as, for example, a RAID card, that exhibit high power consumption only during specific activities such as disc accesses. For the remainder of the time, such cards do not require the PSU to make the maximum power available and do not require the cooling system to accommodate such high power consumptions. [0005] FIG. 1 shows, schematically, an assembly 100 of a motherboard 102 and a PCI or AGP card 104 . The card 104 communicates with the motherboard 102 , that is, the remainder of the chip set (not shown) of the motherboard, via a PCI bus 106 , which is dynamic and used for controlling the operation of the card and interacting with the card 104 . Two static pins, PRSNT [1:2] 108 , are used to inform the motherboard 102 of the power consumption requirements of the PCI or AGP card 104 . [0006] FIG. 2 shows the electrical aspects 200 of the assembly of FIG. 1 . The PRSNT pins 108 are both connected to the motherboard 102 via a buffer 202 . The input 204 to the buffer 202 is connected to V CC via a 5 kΩ resistor 206 and to ground via a 10 nF capacitor 208 . This pin is left floating or is tied to ground according to the maximum power consumption of the card. It will be appreciated, for the purposes of clarity only, that the electrical configuration for a single one of the PRSNT pins 108 has been shown. However, it will be appreciated by those skilled in the art that the same configuration applies to both of the PRSNT [1:2] pins 108 . [0007] Table 1 below shows the current PCI 2.3 specification “present signal” definition for the signals carried by the PRSNT pins 108 that indicate whether or not a PCI or AGP card is present and, if so, provide an indication of the maximum power consumption class of that card. TABLE 1 PRSTN1# PRSTN2# ADD-IN CARD CONFIGURATION Open Open Add-in Card not present Ground Open Add-in card present, 25 W maximum Open Ground Add-in card present, 15 W maximum Ground Ground Add-in card present, 7.5 W maxiumum [0008] It can be appreciated from table 1 that the PCI 2.3 specification arranges for the PCI or AGP add-in card to provide an indication of its presence and an indication of its maximum power consumption to the motherboard. [0009] As mentioned above, a significant limitation of the prior art is that the PCI 2.3 specification provides for the cards to supply an indication of their maximum power consumption requirements. The specification does not accommodate dynamic changes in the actual power consumption or cooling requirements of those cards. [0010] It is an object of embodiments of the present invention at least to mitigate some of the problems of the prior art. SUMMARY OF THE INVENTION [0011] Accordingly, a first aspect of embodiments provides an arrangement for a computer system; the arrangement comprising at least one terminal to output dynamic information relating to a first operating characteristic of the arrangement; and circuitry, using the at least one terminal, to produce the output signal bearing the dynamic information associated with the first operating characteristic of the arrangement. [0012] Preferably, there is provided an arrangement comprising further circuitry to output, via the at least one terminal, static information relating to a second operating characteristic of the arrangement. [0013] Advantageously, the current power consumption or cooling requirements of a card can be supplied to the PSU or the cooling system dynamically, that is, in a real-time manner. Therefore, the PSU can manage the power requirements, and, in turn, its own operation in light of the actual power requirements of the card or computer system. Alternatively or additionally, the cooling system can be used more efficiently since it can be arranged to respond to the actual cooling requirements of the computer system, that is, of any PCI or AGP cards that are present, rather than operating according to an anticipated maximum. It will be appreciated that additional benefits of embodiments of the present invention might include reduced acoustic noise and power saving, since the cooling system fan might be operating at a reduced level or a further power saving attributed to the PSU being operated according to actual power requirements rather than anticipated maximum power requirements. [0014] In preferred embodiments, the circuitry comprises means to produce the output signal as a pulse width modulated signal; the duty cycle of which provides the dynamic information. Preferably, the means to produce the output signal as a pulse width modulated signal is responsive to an input signal. Still more preferably, the means to produce the output signal as a pulse width modulated signal is responsive to an input signal receivable from a motherboard via a second terminal. [0015] The information relating to the first operating characteristic might relate to, for example, temperature or current power consumption. Therefore, embodiments provide an arrangement in which the circuitry comprising the means to produce the output signal comprises a measurement device such that the output signal bearing information associated with at least the first operating characteristic is derived from the measurement device. Preferred embodiments provide an arrangement in which the measurement device is a temperature measurement device and the first operating characteristic is a current temperature of the at least one device of the arrangement. [0016] Embodiments are provided in which the circuitry comprises a comparator for comparing an output of the measurement device with an input signal to produce a signal having a variable duty cycle indicative of the first operating characteristic. It will be appreciated that while the comparator, and other components of the circuits contained within or on the card, can be implemented using discrete or integrated components, other implementations are possible. For example, the circuitry might comprise a mixture of hardware and software for implementing the comparison operation. [0017] There are many computer systems in existence that will not be arranged to exploit the additional functionality offered by embodiments of the present invention. Also, for those that can exploit such additional functionality, there will still exist cards that do not offer such additional functionality. Therefore, preferred embodiments provide an arrangement in which the circuitry to produce the output signal bearing the dynamic information is responsive to a further signal to switch the arrangement between two operating states in which the static information and dynamic information are produced. Preferably, the circuitry is arranged to receive the further signal via the at least one terminal. In preferred embodiments, the at least one terminal comprises at least one of PRSNT1 and PRSNT2 pins according to a PCI specification. [0018] Arrangements are provided in which the second operating characteristic is current power consumption. Preferably, arrangements are provided in which the first operating characteristic is a current temperature. [0019] It will be appreciated that a computer system might comprise a number of PCI or AGP cards. Suitably, preferred embodiments provide an arrangement further comprising a combiner to derive the output signal bearing the dynamic information from at least two output signals bearing respective dynamic information. [0020] A preferred realisation of embodiments of the present invention is in the form of a plug-in card. Accordingly, embodiments provide a card for a computer system comprising an arrangement as claimed in any preceding claim. [0021] Preferably, embodiments provide a motherboard comprising an arrangement according to embodiments described herein and means, responsive to at least the output signal bearing the dynamic information, to produce an input signal for a first unit operable according to that input signal. [0022] In preferred embodiments, the first unit comprises a cooling system operable, in response to the input signal, to provide a corresponding cooling capacity; and in which the output signal bearing the dynamic information comprises temperature information. [0023] In alternative embodiments, the first unit, additionally or severally, comprises a power supply system operable, in response to the input signal, to provide a corresponding output power; and in which the output signal bearing the dynamic information comprises power requirement information. [0024] Embodiments provide a motherboard further comprising means to supply the arrangement with a waveform having a predeterminable characteristic. Preferably, the waveform having the predeterminable characteristic is a triangular waveform. [0025] Again, compatibility between embodiments of the present invention and the prior art might be desirable. Suitably, embodiments provide a motherboard further comprising means to generate a signal for causing the arrangement to switch between first and second modes of operation producing static and dynamic information respectively. [0026] Preferably, embodiments provide an assembly comprising a motherboard according to embodiments of the present invention connected to an arrangement according to embodiments of the present invention. [0027] Preferred embodiments provide a computer system comprising such an assembly contained within a housing. BRIEF DESCRIPTION OF THE DRAWINGS [0028] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: [0029] FIG. 1 shows, schematically, relevant portions of a computer system; [0030] FIG. 2 shows, schematically, the electrical assembly of the portions of the computer system shown in FIG. 1 ; [0031] FIG. 3 shows, schematically, an electrical assembly for an add-in card according to a first, basic, embodiment; [0032] FIG. 4 shows a PCI or AGP card and motherboard assembly according to an embodiment; [0033] FIG. 5 depicts graphs of signals according to an embodiment; [0034] FIG. 6 illustrates the two-state nature of the PCI or AGP and motherboard assembly according to power-up and dynamic modes of operation; [0035] FIG. 7 illustrates a further embodiment; [0036] FIG. 8 shows graphs of signals for dynamic power or cooling management for a 15 W card; [0037] FIG. 9 shows graphs of signals for dynamic power or cooling management for a 7.5 W card; [0038] FIG. 10 shows graphs of signals for dynamic power or cooling management for a 25 W card; [0039] FIG. 11 illustrates graphs for detecting compatibility between embodiments of the present invention and the prior art; [0040] FIG. 12 also illustrates graphs for detecting compatibility between embodiments of the present invention and the prior art; [0041] FIG. 13 shows an assembly comprising a number of cards according to an embodiment; and [0042] FIG. 14 depicts the signals associated with the embodiment shown in FIG. 13 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0043] FIG. 3 shows the electrical assembly 300 of a PCI or AGP card according to an embodiment of the present invention and a motherboard 102 . It will be appreciated that only one 304 of the PRSNT pins is illustrated rather than the two PRSNT [1:2] pins 108 shown in FIG. 1 . This is for the purposes of clarity only. It will be appreciated that the circuit shown in FIG. 3 is equally applicable to both PRSNT pins. The pin 304 is connected to a respective buffer 306 that has its input connected to V CC via a 5 KΩ resistor 308 and is connected to ground via a 10 nF capacitor 310 . Within, or on, the PCI or AGP card 302 , the pin 304 is grounded via a 100 Ω resistor 312 . Replacing the direct ground connection of the prior art PCI or AGP cards with a pull-down 100 Ω resistor achieves the same signalling effect as shown above in table 1 while concurrently allowing a further signal to be transmitted via the pin 304 . Therefore, embodiments of the present invention, rather than leaving the pin 304 floating or being connected to ground directly, leave the pin floating or connected to ground via the 100 Ω resistor 312 according to the signalling requirements of the PCI or AGP card 302 . Hence, table 1 above is modified as shown in table 2 for embodiments of the present invention. ADD-IN CARD PRSTN1# PRSTN2# CONFIGURATION Open Open Add-in Card not present Grounded by 100 Ω Open Add-in card present, 25 W resistor maximum Open Grounded by 100 Ω Add-in card present, 15 W resistor Grounded by 100 Ω Open Add-in card present, 7.5 W resistor maximum [0044] It will be appreciated that the arrangement shown in FIG. 3 assists in maintaining compatibility between motherboards that can accommodate dynamic power management or dynamic cooling according to embodiments of the present invention and those that cannot, that is, those that expect a PCI or AGP card according to embodiments and a conventional PCI or AGP card such as shown in, and described with reference to, FIGS. 1 and 2 respectively. [0045] Referring to FIG. 4 , there is shown an assembly 400 comprising the PCI or AGP card 302 together with circuits 402 and 404 for the first PRSNT pin 304 and the second PRSNT pin 304 ′ respectively. The first and second PRSNT pins 304 and 304 ′ represent embodiments of terminals. The first pin PRSNT 304 provides an indication to the motherboard 102 of the current temperature of the PCI or AGP card. The current temperature information or status is provided by the duty cycle of the signal output via the first PRSNT pin 304 . The duty cycle is used to convey the temperature information in preference to a conventional analogue signal level since using the duty cycle has greater noise immunity as compared to using a conventional analogue threshold signal level together with a comparator detecting the level of that analogue signal. It can be seen that the circuit 402 comprises the 5 kΩ resistor 308 , the buffer 306 and the 10 nF capacitor 310 as described above in relation to FIG. 3 . Similarly, the circuit 404 also comprises a respective buffer 306 ′, a 5 kΩ resistor 308 ′ and a 10 nF capacitor 310 ′. [0046] It can be seen that each of the pins 304 and 304 ′ have respective 100 Ω resistors 312 and 312 ′. The PCI card 302 comprises a temperature measurement device 406 . The temperature measurement device 406 , in preferred embodiments, is located next to the most critical component of the card, and in some implementations can even be included in the silicon of the AGP or PCI card processor as a thermal diode on the PCI or AGP card 302 . Therefore, in the case of an AGP card, the temperature measurement device 406 would be placed adjacent to, or form part of, the video processor (not shown). It will be appreciated that this will provide a reasonably accurate indication of the operating temperature of the video processor. [0047] The motherboard 102 is arranged to supply a triangular-shaped signal 407 to the PCI or AGP card 302 via the buffer 306 ′ connected to the second PRSNT pin 304 ′. The frequency of the triangular-waveform is preferably between 100 hertz and 1 kilohertz. This frequency range is preferred since it is desirable that the triangle signal is not modified significantly by the RC (5 k, 10 nF) filter. Hence, the maximum frequency is substantially 10 kHz and the minimum frequency is defined to be other than zero, that is, other than a continuous value. An optional amplifier 408 is provided on the PCI card 302 to scale the triangular waveform 407 before using that waveform 407 to perform a comparison between a signal 410 output from the temperature measurement device 406 and the output 412 of the amplifier 408 . Preferably, the comparison is performed using a comparator 413 . The output 414 of the comparator 413 is connected to the first PRSNT pin 304 . The signal (not shown) carried by this output 414 has a variable duty cycle. The duty cycle varies according to the current temperature detected by the temperature measurement device 406 . The output signal (not shown) is forwarded to the motherboard 102 via the buffer 306 . Therefore, it can be appreciated that dynamic temperature information related to a current operating temperature of the PCI or AGP card 302 can be provided by that card 302 to the motherboard 102 for subsequent processing. The subsequent processing might include adjusting the level of operation of the cooling system or PSU of the computer system. [0048] Referring to FIG. 5 , there is shown, for the purpose of illustration only, a number of graphs 500 including a graph 502 of the output signal 410 of the temperature measurement device 406 with time, which shows a normal temperature variation; a graph 504 showing the triangular waveform 407 fed from the motherboard to the PCI or AGP card 302 , with the output signal 410 of the temperature measurement device 406 superimposed; and a graph 506 showing a pulse width modulation signal or variable duty cycle signal 508 that provides an indication to the motherboard, via the first PRSNT pin 304 , of the current temperature of the PCI or AGP card 302 . It can be appreciated that the pulse width or duty cycle of the waveform 508 shown in the pulse width modulation waveform graph 506 also varies as the temperature varies. In the particular embodiment shown, as the temperature of the PCI or AGP card increases, the duty cycle of the pulses shown in the PWM waveform graph 506 decreases. [0049] Therefore, the PWM waveform graph 506 can be used to vary the operation or effectiveness of the cooling system to accommodate, dynamically, actual variations in power consumption or temperature of the PCI or AGP card 302 . It can be appreciated that accommodating dynamic temperature measurement of a PCI or AGP card 302 has been achieved while maintaining compatibility with the PCI 2.3 specification PRSNT pin requirements. [0050] It will be appreciated from table 1 that, within the context of the current PCI specification, one of the two pins 108 is necessarily tied to ground. Therefore, embodiments of the present invention use the fact that the two pins 108 in the prior art are never both high together. It will be appreciated, however, that there is still a need for the PCI card 302 to make its presence known to the motherboard regardless of whether or not the motherboard can accommodate the dynamic temperature measurement of a PCI card according to embodiments of the present invention. Therefore, referring to FIG. 6 , it can be appreciated that the computer system and the PCI card have two states 602 and 604 between which the computer system or PCI card can transition via a system activation transition 606 and a PCI reset# signal transition 608 . Within the first state 602 , the PCI card operates as a conventional card in that it reports its presence and its maximum operating power requirements. This ensures compatibility with both the existing PCI 2.3 specification and motherboards that can accommodate prior art PCI cards only. Once the computer system has been initialised, the PCI card or computer system enters the second state 604 in which dynamic temperature reporting is made effective. The PCI card and a compatible motherboard switch between the two states by undergoing a system activation transition 606 . In a preferred embodiment, the motherboard starts, by default, in the compatibility mode 602 and, at a predetermined BIOS step or operation or upon launch of a predetermined driver, undergoes a transition to the enhanced mode 604 . The PCI card 302 and a compatible motherboard can transition from the second mode or state 604 of operation to the first state 602 in response to the PCI reset# signal. [0051] FIG. 7 illustrates additional circuitry used to support the two-state mode of operation described in FIG. 6 , that is, to support transitions between a static mode of operation and a dynamic mode of operation. It will be appreciated that the assembly 700 shown in FIG. 7 has much in common with the arrangement 400 shown in FIG. 4 . Like reference numerals perform substantially the same function and will not be described in detail except where necessary to illustrate the dual-state operation of embodiments of the present invention. It can be appreciated that the circuit 402 shown in FIG. 7 comprises an additional buffer 702 . The additional buffer 702 of the circuit 402 and the existing buffer 306 ′ of the circuit 404 are used to provide a signal to the PCI card that it should enter the dynamic mode of operation or the second state 604 . This signal is provided by forcing the two PRSNT pins 304 and 304 ′ high via the buffers 702 and 306 ′. An AND gate 704 is used to detect the presence of the high signals fed via buffers 702 and 306 ′. The AND gate 704 produces a 1, or high output signal, in response to the high inputs to the buffers 702 and 306 ′. The output 706 from the AND gate 704 is latched using a D-type latch 708 . The output 710 of the D-type latch 708 is connected to an output enable pin 712 of the comparator 413 . The output enable pin 712 controls the operation of the comparator 413 such that, when the output signal 710 of the D-type latch 708 assumes a predetermined state, the output of the comparator 413 is enabled, which allows the PCI card 302 to commence temperature reporting. It will be appreciated by one skilled in the art that the PCI card 302 will operate as a conventional PCI card in the absence of the PRSNT pins 304 and 304 ′ being forced high. Therefore, if the PCI card is plugged into a PCI slot of a conventional motherboard that does not expect dynamic temperature information, that motherboard will also not supply the high signals to cause a transition from a conventional mode of operation, or first state 602 , to the dynamic temperature reporting mode of operation, or second state 604 . [0052] It will be appreciated that an additional buffer 702 ′ is used to retain compatibility with the PCI specification and prior art motherboards by allowing the card 302 to report its operating power statically. [0053] It can be appreciated from FIG. 7 that, in spite of the presence of the pull-down resistors 312 and 312 ′, the buffers 702 and 306 ′, in response to respective high signals, are arranged to force the PRSNT pins 304 and 304 ′ high. It should be noted that, in preferred embodiments, the comparator 413 should be such that it can sustain a buffer to buffer connection in any logical state during the state transitions. It will be appreciated that, in preferred embodiments, the comparator 413 has a tri-state output until a PCI_RESET# signal 714 is received by the D-type latch. [0054] Referring to FIG. 8 , there are shown several graphs 800 of the signals used by the embodiment shown in FIG. 7 for a 15 watt card. A PCI_RESET graph 802 shows the PCI_RESET# signal 714 slowly ramping up until it reaches a high state whereupon, after a predetermined period of time, a negative going pulse 804 causes the D-type latch 708 to reset. The negative going pulse is an embodiment of the PCI_RESET#signal. During power-up, the first PRSNT pin, is shown by the second graph 806 , has a “don't care” state. After power up, at point 808 , it assumes a high state. Similarly, the second PRSNT pin as shown by the third graph 810 , also has a “don't care state” until a predetermined point in time 808 , whereupon the second PRSNT pin 304 ′ assumes a low state. It can be seen from the temperature graph 812 that the temperature is shown, for the purposes of illustration, as being substantially constant. The static-to-dynamic buffer graph 814 reflects the signals applied to the buffers 702 and 306 ′. In predetermined embodiments, the high signals described above are applied to both buffers 702 and 306 ′. It can be appreciated that, following the negative going pulse 804 of the PCI_RESET# signal 714 , the static values 816 of the first and second PRSNT pins 304 and 304 ′ can be read by the motherboard such as, for example, a motherboard compatible with embodiments of the present invention or a conventional motherboard, to determine that the card is a 15 watt card. The triangular waveform graph 818 shows that the buffer 306 ′ assumes a tri-state until just before a positive going pulse or high signal is applied to the static-to-dynamic buffer 702 . It can be seen from the second PRSNT pin graph 810 that the waveform present at that pin follows the triangular waveform applied to the buffer 306 ′. It can be seen, following the negative going edge of a pulse 820 applied to the static-to-dynamic buffer 702 , that the signal on the first PRSNT pin 304 is a pulse width modulated signal reflecting the current operating temperature of the PCI card. The point at which the output of the D-type latch 708 enables the output of the comparator 412 is shown by reference numeral 822 on the second PRSNT pin graph 810 , that is, when the signals on the pins 304 and 304 ′ are both high. [0055] FIG. 9 shows graphs 900 similar to those shown in FIG. 8 but for a 7.5 watt card rather than for a 15 W card. Like reference numerals are applied to like features, which perform substantially the same function or have substantially the same characteristics. It will be appreciated that the main differences between FIG. 9 and FIG. 8 reside in the graphs 806 and 810 for the first PRSNT and second PRSNT signals, which are both shown as being low during the period when the static information is read 816 . It can be appreciated that the point at which the output of the D-type latch 708 enables the output of the comparator 413 is also at the second peak of the triangular waveform as shown by reference numeral 822 . [0056] FIG. 10 illustrates the signals 1000 for an embodiment of a 25 W PCI card. It can be appreciated that the main differences between the signals as shown in FIGS. 9 and 10 are, again, that the static values 816 are low and high to provide an indication to the system that the card is a 25 watt card. It can be seen that the output of the D-type latch 708 enables the output of the comparator 413 , again, on the second peak of the triangular waveform as indicated by reference numeral 822 . [0057] FIG. 11 illustrates the signals that result when a conventional PCI card is plugged into a motherboard that expects, or is capable of responding to, dynamic temperature reporting card according to embodiments of the present invention. It can be appreciated that the graphs 1100 shown in FIG. 11 have much in common with the graphs shown in FIGS. 8, 9 and 10 . Therefore, like reference numerals refer to like features and will not be described in detail. The main difference between the graphs 1100 shown in FIG. 11 and the earlier graphs of FIGS. 8, 9 and 10 resides in the PRSNT graph 806 for the first PRSNT pin 304 . It can be seen from the PRSNT graph 806 that an invalid read value 1102 is obtained when the high signal of the static to dynamic buffer 706 is applied. It can be appreciated that if the PCI card was a card in accordance with an embodiment of the present invention, the PRSNT pin would have gone high and produced a pulse width modulated signal as shown in the corresponding graph of FIG. 10 . [0058] FIG. 12 shows graphs 1200 corresponding to those of FIG. 11 but for a case where the second PRSNT pin 304 ′ is tied low by a direct ground connection. It can be appreciated that a motherboard, following application of the high signal to the static to dynamic buffer 706 or the triangular waveform to the other buffer 306 ′, will detect an invalid signal or read value 1202 at the second pin PRSNT 304 ′ rather than the triangular waveforms as shown in FIGS. 8 and 9 . [0059] Using the invalid read signals 1102 and 1202 allows a motherboard in accordance with embodiments of the present invention to determine whether or not a PCI card in accordance with embodiments of the present invention or a prior art PCI card has been placed in a PCI or AGP slot. [0060] Referring to FIG. 13 , there is shown an assembly 1300 in which a PCI card 1302 and an AGP card 1304 in accordance with the embodiments of the present invention are provided. The outputs of the PRSNT pins 1306 and 1308 of the cards are combined, during the dynamic mode of operation, using respective command buffers 1310 and 1312 and an AND gate 1314 . The AND gate 1314 represents an embodiment of a combiner. The output 1316 from the AND gate 1314 is used by the cooling system to control, for example, the fan speed. It will be appreciated, due to the logical gate being an AND gate, that the cooling system responds to the highest demands or cooling requirements of the hottest card. FIG. 14 illustrates this principle. The PCI card signal 1402 is shown as having a relatively wide pulse width 1404 as compared to an AGP signal 1406 , which is shown as having a relatively narrow pulse width 1408 . Therefore, the output 1322 of the AND gate has a duty cycle 1410 corresponding to that of the AGP signal 1406 . [0061] Although the above embodiments have been illustrated or described with reference to the triangular waveform 407 being supplied by the motherboard to the PCI or AGP card, embodiments are not limited to such an arrangement. Embodiments can be realised in which the PCI or AGP card is calibrated to generate its own triangular waveform. Still more preferably, embodiments can be realised in which a variable pulse width signal or variable duty cycle signal complying with prescribed regulations or having prescribed specifications is output via the PCI or AGP card. However, preferred embodiments arrange for the motherboard to supply the triangular waveform 407 rather than having each card generate its own waveform, which means that a single triangular waveform generator can be used with several PCI or AGP cards. [0062] The above embodiments have been described within the context of providing dynamic information associated with an operating characteristic of a plug-in card such as, for example, PCI or AGP cards. However, embodiments of the present invention are not limited thereto. Embodiments can be realised in which a chip or chip-set for a motherboard employs the principles described above. Therefore, various arrangements, such as PCI cards, AGP cards, chips or chip-sets can be realised to provide dynamic information associated with an operating characteristic of a device of such PCI cards, AGP cards, chips or chip-sets. [0063] Furthermore, even though the above embodiments have been described with reference to the measurement device being a temperature measurement device, embodiments can be realised in which other measurement devices are used. For example, a Hall effect device might be used to monitor the current being supplied to the arrangement or card to estimate the current being consumed by the card and thereby to estimate the current power consumption of the card or arrangement. [0064] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. [0065] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings) and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. [0066] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. [0067] The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

The present invention relates to computer systems. An embodiment provides an arrangement for a computer system; the arrangement comprising at least one terminal to provide dynamic information relating to an operating characteristic of the arrangement; and circuitry, using the at least one terminal, to produce an output signal bearing the dynamic information associated with the operating characteristic of the arrangement.

CROSS-REFERENCE TO RELATED APPLICATION [0001] The present application claims priority to Korean Patent Application No. 10-2014-0172136 filed Dec. 3, 2014, the entire contents of which is incorporated herein for all purposes by this reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an engine system having a coolant control valve capable of simplifying an overall layout of a cooling system and enhancing control stability of a coolant by disposing the coolant control valve on an entrance side of a coolant of an engine and coupling the coolant control valve and a coolant pump. [0004] 2. Description of Related Art [0005] An engine generates rotary power based on combustion of fuel and discharges the remaining energy as thermal energy. In particular, a coolant, while circulating in an engine, a heater, and a radiator, absorbs and discharges the thermal energy. [0006] When a temperature of the coolant of the engine is low, viscosity of oil may increase to increase frictional force and fuel consumption, and a temperature of an exhaust gas may increase gradually to lengthen a time for a catalyst to be activated which degrades quality of the exhaust gas. In addition, a time required for a function of the heater to be normalized is increased to make a passenger or a driver feel cold. [0007] If the temperature of the coolant of the engine is too high, knocking is generated, and adjustment of ignition timing to suppress generation of knocking may degrade performance. Also, if the temperature of the lubricant is too high, a lubricating operation may be degraded. [0008] Thus, a single coolant control valve is applied to control several cooling elements such that the temperature of the coolant in a particular portion is maintained to be high and the temperature of the coolant in another portion is maintained to be low. [0009] Among the several cooling elements, a cylinder block and a cylinder head are important, and a technique of separately cooling the cylinder block and the cylinder head has been researched. [0010] Even though a single coolant control valve is used, an exit control scheme of controlling coolant discharged from the engine (cylinder block and cylinder head) and an entrance control scheme of controlling a coolant supplied to the engine are still generally used. [0011] The exit control scheme may be vulnerable to rapid fluctuations of coolant temperature, precision of temperature controlling is lowered, and durability of the coolant control valve may be degraded. [0012] In addition, the coolant pump is installed on the coolant entrance side of the engine together with the coolant control valve, and the coolant pump is installed on the coolant entrance side of the engine, resulting in a complicated layout of the cooling system overall. [0013] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. BRIEF SUMMARY [0014] Various aspects of the present invention are directed to providing an engine system having a coolant control valve having advantages of appropriately coping with rapid fluctuation in a coolant temperature, enhancing precision of temperature control, and simplifying a layout of a cooling system through a coupling structure of a valve housing and a pump housing. [0015] According to various aspects of the present invention, an engine system having a coolant control valve may include a cylindrical valve having a pipe structure with one side opened and including coolant passages formed in preset positions from one inner circumferential surface to an outer circumferential surface of the cylindrical valve to allow a coolant to pass therethrough, a valve housing configured for the cylindrical valve to be rotatably disposed therein and having connection pipes connected thereto to correspond to the coolant passages, a valve driving device disposed in one end portion of the valve housing to rotate the cylindrical valve to connect the connection pipes and the coolant passages, a pump housing disposed in one end portion of the cylindrical valve to correspond to the opened side of the cylindrical valve, having a pump impeller disposed therein, and coupled to the valve housing, a pump driving device disposed to rotate the pump impeller, and a pump discharge line connected to the pump housing to transmit a coolant pumped by the pump impeller to a cylinder block. [0016] The coolant pumped by the pump impeller may be supplied to the cylinder block through the pump discharge line, and a portion of the coolant supplied to the cylinder block may be supplied toward a cylinder head disposed above the cylinder block. [0017] A remaining portion of the coolant, which has been supplied to the cylinder block, is supplied toward an oil cooler. [0018] The coolant discharged from the cylinder head may be distributed to an exhaust gas recirculation (EGR) cooler, a heater core, or a radiator. [0019] The connection pipes may include a first connection pipe configured to supply coolant discharged from the EGR cooler and the heater core to an inner side of the valve housing, a second connection pipe configured to supply coolant discharged from the radiator to the inner side of the valve housing, and a third connection pipe configured to supply coolant discharged from the oil cooler to the inner side of the valve housing. [0020] The cylindrical valve and the pump impeller may be arranged to be adjacent in a horizontal direction. [0021] The cylindrical valve and the pump impeller may be arranged to be adjacent in a vertical direction. [0022] The pump housing and the valve housing may be integrally formed. [0023] Sealing members may be interposed between an inner circumferential surface of the valve housing and an outer circumferential surface of the cylindrical valve such that the sealing members correspond to the connection pipes. [0024] The EGR cooler and the heater core may be disposed in a single coolant line. [0025] The cylindrical valve and the pump impeller may be disposed such that rotation central axes thereof are aligned or are perpendicular to each other. [0026] According to various embodiments of the present invention, since the coolant control valve is installed in the coolant entrance side of the engine to enhance temperature control precision of a coolant and the coolant control valve and the coolant pump are coupled to be configured as a single module, a layout of the cooling system may be simplified. [0027] In addition, since the coolant control valve separately cools the cylinder head and the cylinder block and separately controls the coolants circulating in the EGR cooler, the heater core, the oil cooler, and the radiator, overall stability of the cooling system and control efficiency may be enhanced. [0028] It is understood that the term “vehicle” or “vehicular” or other similar terms as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuel derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example, both gasoline-powered and electric-powered vehicles. [0029] The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0030] FIG. 1 is a flowchart illustrating an overall flow of a coolant in an exemplary engine system having a coolant control valve according to the present invention. [0031] FIG. 2 is a partial cross-sectional view of the exemplary engine system having the coolant control valve according to the present invention. [0032] FIG. 3 is a partial cross-sectional view of an exemplary engine system having a coolant control valve according to the present invention. [0033] FIG. 4 is a partial cross-sectional view of the coolant control valve related to the present invention. [0034] It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. DETAILED DESCRIPTION [0035] Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. [0036] FIG. 1 is a flowchart illustrating an overall flow of a coolant in an engine system having a coolant control valve according to various embodiments of the present invention. [0037] Referring to FIG. 1 , an engine system includes a coolant control valve 100 , a cylinder head 110 , a cylinder block 120 , an oil cooler 130 , a radiator 140 , a heater core 150 , an exhaust gas recirculation (EGR) cooler 160 , and a coolant pump 170 . [0038] The coolant pump 170 is integrally coupled with the coolant control valve 100 , and pumps a coolant discharged to the coolant control valve 100 to supply the coolant to the cylinder block 120 . [0039] The coolant supplied to the cylinder block 120 is distributed to the cylinder head 110 , the coolant flowing through the cylinder block is discharged to the oil cooler 130 , and the coolant supplied to the cylinder head 110 is distributed to the EGR cooler 160 , the heater core 150 , and the radiator 140 . The heater core 150 and the EGR cooler 160 are connected by a single coolant line. [0040] In addition, the coolant discharged from the heater core 150 and the EGR cooler 160 , the coolant discharged from the oil cooler 130 , and the coolant discharged from the radiator 140 recirculate to the coolant control valve 100 to be pumped by the coolant pump 170 again. [0041] Thus, when the coolant control valve 100 blocks the coolant discharged from the heater core 150 and the EGR cooler 160 , the coolant does not circulate to the heater core 150 and the EGR cooler 160 , when the coolant control valve 100 blocks the coolant discharged from the oil cooler 130 , the coolant does not circulate to the oil cooler 130 and the cylinder block 120 , and when the coolant control valve 100 blocks the coolant discharged from the radiator 140 , the coolant does not circulate to the radiator 140 . [0042] In addition, when the coolant control valve 100 blocks the coolant discharged from the heater core 150 , the EGR cooler 160 , and the radiator 140 , the coolant does not circulate to the cylinder head 110 . [0043] In various embodiments of the present invention, the heater core 150 serves to heat an interior space of a vehicle using a warm circulating coolant, the EGR cooler 160 serves to cool a recirculation exhaust gas recirculating from an exhaust line to an intake line, the radiator 140 serves to outwardly release heat of the coolant, and the oil cooler 130 serves to cool oil circulating through the cylinder head 110 or the cylinder block 120 . [0044] As described above, the coolant control valve 100 and the coolant pump 170 may be integrally coupled to reduce assembling cost and simplify the layout. [0045] In addition, since an entrance control scheme instead of an exit control scheme is applied to the coolant, coolant stability of the engine may be enhanced, and since the coolants circulating in the cylinder block 120 , the cylinder head 110 , the EGR cooler 160 , the heater core 150 , and the radiator 140 are separately controlled by the single coolant control valve 100 , an overall cooling system may be effectively controlled. [0046] FIG. 2 is a partial cross-sectional view of the engine system having a coolant control valve according to various embodiments of the present invention. [0047] Referring to FIG. 2 , the coolant control valve 100 includes a cylindrical valve 320 , a valve housing 302 , a motor housing 300 , a rotational shaft 315 , a first connection pipe 240 , a second connection pipe 242 , and a third connection pipe 244 , and the coolant pump 170 includes a pump housing 220 , a pump impeller 200 , a pump motor 210 , and a pump discharge pipe 230 . [0048] The valve housing 302 and the pump housing 220 are integrally formed, the motor housing 300 in which a motor 360 is installed is disposed in one end portion of the valve housing 302 , and the cylindrical valve 320 is installed within the valve housing 302 . [0049] The cylindrical valve 320 has a pipe structure in which the interior is hollow and one side thereof is open, and coolant passages 321 are formed in preset positions from an inner circumferential surface to an outer circumferential surface. As illustrated, three coolant passages 321 may be formed in preset positions. [0050] The cylindrical valve 320 is connected to the motor 360 of the motor housing 300 through the rotational shaft 315 , and is disposed to be rotatable about the rotational shaft 315 according to rotation of the motor 360 . [0051] The pump impeller 200 is disposed within the pump housing 220 at a preset interval from the other end of the cylindrical valve 320 , and the pump motor 210 is disposed to rotate the pump impeller 200 . When the pump impeller 200 rotates by the pump motor 210 , the coolant present within the cylindrical valve 320 is sucked and pumped in a radial direction of the pump impeller 200 . [0052] The coolant pumped by the pump impeller 200 is directly supplied to the coolant chamber of the cylinder block 120 through the pump discharge pipe 230 . [0053] In various embodiments of the present invention, the first connection pipe 240 , the second connection pipe 242 , and the third connection pipe 244 are connected to the valve housing 302 to correspond to the coolant passages 321 . The first connection pipe 240 receives the coolant from the heater core 150 and the EGR cooler 160 , the second connection pipe receives the coolant from the radiator 140 , and the third connection pipe 244 receives the coolant form the oil cooler 130 . [0054] In addition, sealing members 324 are interposed between an inner circumferential surface of the valve housing 302 and the cylindrical valve 320 such that the sealing members 324 correspond to the first, second, and third connection pipes 240 , 242 , and 244 , enhancing control precision of the coolant. [0055] As illustrated, the valve housing 302 and the pump impeller 200 are disposed in a horizontal direction, and one open portion of the valve housing 302 is disposed to be adjacent to the pump impeller 200 , thereby minimizing intake resistance of the pump impeller 200 . [0056] Here, a rotation central axis of the pump impeller 200 and a rotation central axis of the cylindrical valve 320 are aligned. In addition, the rotation central axis of the pump impeller 200 and the rotation central axis of the cylindrical valve 320 may be disposed to be parallel, rather than being coaxial. [0057] FIG. 3 is a partial cross-sectional view of the engine system having a coolant control valve according to various embodiments of the present invention. Differences from the various embodiments of FIG. 2 will be described. [0058] Referring to FIG. 3 , the motor housing 300 , the cylindrical valve 320 , the pump impeller 200 , and the pump motor 210 are arranged vertically in an upward direction. [0059] In various embodiments of the present invention, the pump motor 210 , the pump impeller 200 , the cylindrical valve 320 , and the motor housing 300 may be arranged vertically in an upward direction. [0060] As illustrated, since the valve housing 302 and the pump impeller 200 are disposed in a vertical direction and the upper open portion of the valve housing 302 is disposed to be adjacent to the pump impeller 200 , intake resistance of the pump impeller 200 may be minimized. [0061] Here, the rotation central axis of the pump impeller 200 and the rotation central axis of the cylindrical valve 320 are disposed to be perpendicular to each other. In addition, the pump impeller 200 and the cylindrical valve 320 may be disposed such that a rotation central axis of the pump impeller 200 and a rotation central axis of the cylindrical valve 320 are aligned. [0062] As described above, since the cylindrical valve 320 and the pump impeller 200 are arranged in the vertical direction, the overall coolant pump 170 and the coolant control valve 100 are disposed vertically or horizontally in a length direction, whereby a layout coupled to the engine may be variously modified. [0063] FIG. 5 is a partial cross-sectional view of the coolant control valve related to the present invention. The coolant control valve illustrated in FIG. 5 is for better understanding of the present invention, and the structure of the coolant control valve according to the present invention differs from that of previously described embodiments in some parts. [0064] Referring to FIG. 4 , the coolant control valve 100 includes the motor housing 300 in which the motor 360 is installed, an output gear 305 rotated by the motor, and a driven gear 310 rotated by the output gear 305 . The driven gear 310 is disposed to rotate the cylindrical valve 320 . [0065] The cylindrical valve 320 has a pipe structure in which both ends thereof are open and a space is formed in a central portion in a length direction thereof. Coolant passages 321 leading from a space of the central portion to an outer surface are formed in the cylindrical valve 320 . [0066] In the valve housing 302 in which the cylindrical valve 320 is installed, a first entrance pipe 325 is disposed in one end portion and the motor housing 300 is connected to the other end portion. [0067] In the valve housing 302 , a radiator supply pipe 340 connected to the radiator 140 , a second entrance pipe 330 connected to the cylinder head, and a heater supply pipe 335 connected to the heater are disposed. [0068] The sealing members 324 are disposed on an outer circumferential surface of the cylindrical valve 320 , a front end portion of the radiator supply pipe 340 is inserted to an inner side of the sealing members 324 , and an elastic member 326 elastically pushes the sealing members 324 toward an outer circumferential surface of the cylindrical valve 320 , thus forming a sealing structure. [0069] A control unit controls the motor within the motor housing 300 according to operation conditions, namely, a coolant temperature, an intake temperature, and the like, to rotate the cylindrical valve 320 with respect to the rotational shaft 315 disposed along the central axis of the cylindrical valve 320 in the length direction through the output gear 305 and the driven gear 310 . [0070] Also, when the passages 321 of the cylindrical valve 320 correspond to the first entrance pipe 325 or the second entrance pipe 330 , the coolant flows. [0071] For convenience in explanation and accurate definition in the appended claims, the terms “upper” or “lower”, “inner” or “outer” and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. [0072] The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.

An engine system having a coolant control valve may include a cylindrical valve having a pipe structure with one side opened and including coolant passages formed in preset positions from one inner circumferential surface to an outer circumferential surface of the cylindrical valve to allow a coolant to pass therethrough, a valve housing configured for the cylindrical valve to be rotatably disposed therein and having connection pipes connected thereto to correspond to the coolant passages, a valve driving device, a pump housing disposed in one end portion of the cylindrical valve to correspond to the opened side of the cylindrical valve, having a pump impeller disposed therein, and coupled to the valve housing, a pump driving device disposed to rotate the pump impeller, and a pump discharge line connected to the pump housing to transmit a coolant pumped by the pump impeller to a cylinder block.

FIELD OF THE INVENTION The present invention relates to an iron, especially an iron of which the steam brush and the base of the metal soleplate are disassembled. BACKGROUND OF THE INVENTION The existing irons are disposed with a metal soleplate, which has a heating pan, in the lower portion of the housing. A thermoregulator is disposed inside the housing to control the power to the heating pan and then change the heat radiation of the metal soleplate; the housing is disposed with thermoregulator knob, which is directly connected to the level lever of thermoregulator to regulate the level of the electricity output of the thermoregulator. To expand the use mode of the iron, combining a steam brush set and a base set to be a biservice iron. The steam boiler of electrical heated is disposed inside the housing of the steam brush set. The steam outlet of the steam brush is connected to the outside from the bottom of the housing. The electrical wire is led into the housing from the rear portion and connected to the switch of the steam boiler. Turn on the switch, the steam boiler is energized by the external power, the water inside the steam boiler turns into steam and spurts out from the bottom of the housing. A handle is disposed on the housing of the steam brush set for independently usage of garment ironing. The heating pan is disposed at the bottom of the housing of the base set. The thermoregulator is disposed inside the housing to control the power to the heating pan and then change the radial of the heating pan. The housing of the base set is disposed without handle, but the housing of the base set is disposed with an accommodation room for the steam brush set and for locking the lower of the steam brush set. The steam brush set is locked to the base set, forming an iron with a handle for ironing. However, how to realize the thermoregulator knob on the steam brush to disassemble connect to the level lever of the thermoregulator on the base set to regulate the level of the energy output of the thermoregulator is a much vexed problem for the designer. In the disassemble state, the rotation positions of the thermoregulator knob on the steam brush and the level lever of the thermoregulator on the base set are random, making it difficult to make sure that the thermoregulator knob and the level lever of the thermoregulator are rotating synchronously when the steam brush set is locked to the base set. Besides, it's difficult to ensure that the level indicator for the thermoregulator knob can exactly read the present level of the thermoregulator when the thermoregulator knob is randomly connected to the level lever of the thermoregulator. SUMMARY OF THE INVENTION The object of the present invention is to provide with a biservice iron, in which the thermoregulator knob and the level lever of the thermoregulator are rotating synchronously when the steam brush set is locked to the base set. Moreover, the biservice iron is provided that the level indicator for the thermoregulator knob can exactly read the present level of the thermoregulator when the thermoregulator knob is randomly connected to the level lever of the thermoregulator. The technical proposal of the present invention is: a biservice iron includes a steam brush set, a base set and a thermoregulator knob, the thermoregulator knob includes an external knob which is rotatably disposed on the housing of the steam brush set and an inner knob which is rotatably disposed on the housing of the base set, the inner knob is connected to the level lever of the thermoregulator on the housing of the base set, the external knob and the inner knob are connected to each other in socket way with cylinder of which the cross section is equilateral polygon or star-shaped of equilateral polyhedral angle. In another preferred embodiment, the cylinder of which the cross section is equilateral polygon or star-shaped of equilateral polyhedral angle between the external knob and the inner knob is conical surface of slightly inward contraction, the free end of the lever between the external knob and the inner knob is disposed with the corresponding cone of inward contraction and equilateral polygon or star-shaped of equilateral polyhedral angle. The external knob is easy to inserted connected to the inner knob, and it can achieve an automatically modification effect with the cone of inward contraction and equilateral polygon or star-shaped of equilateral polyhedral angle in the free end of the lever between the external knob and the inner knob during the inserting. Moreover, the free end of the lever between the external knob and the inner knob is disposed with at least two grooves. If the position between the external knob and the inner knob is not justified, the free end of the pipe between the above will be slightly opened by the lever, and then it will be modified automatically with the assistant of the elastic restoring force of the free end of the pipe. Especially, the cylinder, of which the cross section is equilateral polygon or star-shaped of equilateral polyhedral angle, is disposed with at least eight side walls or at least nine angles. This makes it easy for the modification automatically during the inserting of the external knob and the inner knob. In another preferred embodiment, for the external knob rotatably disposed on the housing of the steam brush set, the top of the external knob is a disc, the central of the lower surface of the disc is extended downward with at least three lock catches of evenly distribution in the peripheral direction, the catch head of every lock catch is turning inside out; the disc in the upper of the external knob is located above the circle pipe shaped assembly portion on the housing of the steam brush set, the lock catches are inserted into the hole of the assembly portion, the catch heads of the lock catches are locked in the inner flange on the top of the assembly portion. The lock catches evenly distribution in the peripheral direction makes the external knob rotatable and easy to be assembled. In another preferred embodiment, for the inner knob rotatably disposed on the housing of the base set, the central of the inner knob is a circle pipe shaped body, the lower surface of the body is extended downward with at least three lock catches evenly distribution in the peripheral direction, the catch head of every lock catch is turning inside out, the body of the inner knob is located above the circle pipe shaped boss on the upper surface of the housing of the base set, the lock catches are inserted into the hole of the boss, the catch heads of the lock catches are locked in the inner flange on the top of the boss. The lock catches evenly distribution in the peripheral direction makes the inner knob rotatable and easy to be assembled. For the second object of the present invention, the external knob is made of transparent material, the upper surface of the inner flange at the upper portion of the assembly portion is disposed with level scale of the thermoregulator, the upper surface of the insert portion of the inner knob is disposed with marker for indicating the position of the rotation angle of the level lever of the thermoregulator. The marker on the upper surface of the insert portion of the inner knob is read clearly through the external knob. The marker indicates the correspondence between the rotation angle of the level lever of the thermoregulator and the level scale on the thermoregulator on the housing, that is the present level of the thermoregulator. The present invention of a biservice iron includes an inserted thermoregulator knob of disassemble, which includes an external knob rotatably disposed on the housing of the steam brush set and an inner knob rotatably disposed on the housing of the base set. The inner knob is connected to the level lever of the thermoregulator on the housing of the base set to regulate the thermoregulator. The external knob and the inner knob are connected to each other in socket way with cylinder of which the cross section is equilateral polygon or star-shaped of equilateral polyhedral angle, making the thermoregulator knob and the level lever of the thermoregulator are rotating synchronously when the steam brush set is locked to the base set. The present invention of a biservice iron is provided to expand the usage mode of the iron, benefit for the consumer with biservice. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates the foldable structure of the first embodiment of the biservice iron in the present invention. FIG. 2 illustrates the foldable structure of the thermoregulator knob of the FIG. 1 . FIG. 3 illustrates the partial section view of the external knob installing into the steam brush set of the FIG. 1 . FIG. 4 illustrates top view of the inner knob of the FIG. 1 . FIG. 5 illustrates the side view of the inner knob of the FIG. 1 . FIG. 6 illustrates the side view of the inner knob installing to the base set of the FIG. 1 . FIG. 7 illustrates the top view of the inner knob installing to the base set of the FIG. 1 . FIG. 8 illustrates the sectional view of the B-B part of the FIG. 7 . FIG. 9 illustrates the assembled structure of the FIG. 1 . FIG. 10 illustrates the sectional view of the thermoregulator knob in the FIG. 1 ; FIG. 11 illustrates the foldable structure of the second embodiment of the is biservice iron in the present invention. FIG. 12 illustrates the foldable structure of the thermoregulator in the FIG. 11 ; FIG. 13 illustrates the side view of the external knob in the FIG. 11 ; FIG. 14 illustrates the bottom view of the inner knob in the FIG. 11 ; FIG. 15 illustrates the top view of the inner knob in the FIG. 11 ; FIG. 16 illustrates the side view of the inner knob in the FIG. 11 ; FIG. 17 illustrates the sectional view of the thermoregulator knob of assembled in the FIG. 11 ; DETAILED DESCRIPTION OF THE EMBODIMENTS The First Embodiment: The structure of the first embodiment of a biservice iron is figured in the FIG. 1 . The biservice iron includes an independent steam brush set 30 and an independent base set 40 . A handle 32 is disposed on the housing 31 of the steam brush 30 for garment steaming. A steam boiler of electric heated is disposed inside the housing 31 of the steam brush set 30 . The steam outlet pipe of the steam boiler is connected to outside from the steam outlet portion 33 on the bottom of the housing 31 . The electric wire is led into the housing 31 from the rear portion and connected to the switch of the steam boiler. When turning on the switch, the steam boiler is energized by the external power. The water inside the steam boiler turns into steam and spurts out from the steam outlet portion 33 on the bottom of the housing 31 . An assembly portion 34 of circuit pipe shaped is disposed below the handle 32 on the housing 31 of the steam brush set 30 for the assembly of the external knob 10 . The front portion of the housing 31 of the steam brush set 30 is extended down with an insert head 36 . The two sides of the central portion of the housing 31 of the steam brush set 30 are extended down with an insert head 37 each. A catch groove is disposed at the rear of the housing 31 of the steam brush set 30 for holding the overturn catch head 491 of the base set 40 . The rear portion on the lower surface of the housing 31 of the steam brush set 30 is disposed with an electrical outlet for energizing the base set 40 . Please refer to the FIG. 7 and FIG. 8 with combination with the FIG. 1 , the housing 41 of the base set 40 is disposed without a handle. The central of the housing 41 of the base set 40 is disposed with a concave accommodation room 48 to accommodate and catch the lower portion of the steam brush set 30 . The central of the accommodation room 48 is disposed with a circular pipe shaped boss 42 extending upward. The upper surface of the boss 42 is disposed with an upward cog 43 . The heating pan 44 is disposed on the bottom of the housing 41 of the base set 40 . A thermoregulator is disposed inside the housing 41 to energize the heating pan 44 and then change the heat radiation of the heating pan 44 . The level lever 46 of the thermoregulator is disposed inside the boss 42 , and the thermoregulator base 45 which is also inside the boss 42 is disposed on the upper of the level lever 46 , to rotatably connect to the inner knob 20 . The rear portion of the accommodation room 48 is disposed with an electrical plug 47 , which is cooperated with the electrical outlet of the housing 31 of the steam brush set 30 to receive the power from the steam brush set 30 and then energize the thermoregulator. The rear portion of the accommodation room 48 is disposed with an overturn catch head 491 , which is controlled by the lock knob 49 at the rear of the housing 41 of the base set 40 . Put the steam brush set 30 on the accommodation room 48 of the housing 41 of the base set 40 , the insert head 36 in the front of the housing 31 of the steam brush set 30 and the insert heads 37 on the two sides of the central of the housing 31 of the steam brush set 30 are separately withstanding the inner wall of the front and the two sides of the central portion of the accommodation room 48 . The electrical outlet on the lower surface of the housing 31 of the steam brush set 30 is cooperated with the electrical plug 47 at the rear portion of the accommodation room 48 . Rotate the lock knob 49 , making the overturn catch head 491 locked into the catch groove at the rear portion of the housing 31 of the steam brush set 30 , and then the steam brush set 30 is locked to the base set 40 , forming an iron with handle for ironing. The structure of the thermoregulator knob in break state of the embodiment is figured in the FIG. 2 . The thermoregulator knob is consisting of the external knob 10 and the inner knob 20 . Please refer to the FIG. 3 with combination with the FIG. 2 : the external knob is made of transparent material. The upper portion of the external knob 10 is a disc 11 with the opening downward. A circle boss is extended upwards from the central portion of the upper surface of the disc 11 . A circle pipe shaped axle sleeve 12 is extended downward from the central portion of the lower surface of the disc 11 . The inner wall 13 of the axle sleeve 12 is cut into an interior cylinder of polygon with 12 sides of slightly inside shrink. The lower portion of the axle sleeve 12 is cut into three grooves of evenly distribution. The root of the every groove 14 is extending downward with a lock catch 15 of the catch head turning inside out. The distance between the root of the catch head of the three lock catch 15 and the lower edge of the disc 11 is slightly bigger than the wall thickness of the inner flange on the top of the assembly portion 34 of the steam brush set 30 . The length of every lock catch 15 is bigger than that of the axle sleeve 12 to make sure that the depth of the inner wall 13 of the axle sleeve 12 is big enough to accommodate the rod like insert portion 22 of the inner knob 20 . The external knob 10 is inserted into the assembly portion 34 on the housing 31 of the steam brush set 30 . The disc 11 in the upper portion of the external knob 10 is disposed above the assembly portion 34 . The axle sleeve 12 and the three lock catches 15 are dipped into the pipe hole 35 inside the assembly portion 34 . The catch head of the three lock catches 15 are locked in the inner flange at the upper portion of the assembly portion 34 . The upper surface of the inner flange at the upper portion of the assembly portion 34 is printed with level scale of the thermoregulator. The level scale can be read clearly through the disc 11 of the external knob 10 . Please refer to the FIG. 4 and FIG. 5 with combination with the FIG. 2 : the central of the inner knob is a circle pipe shaped body 21 . The upper surface of the body 21 is extended upward with a rod like insert portion 22 of polygon with 12 sides of slightly inside shrink. The size of the insert portion 22 is corresponding to the inner wall 13 of the axle sleeve 12 of the external knob 10 in inserted way. The central of the lower surface inside the body is extended downward with an elongated lifting lever 23 . The lower portion of the lifting lever 23 is cut with a gap for orientation marker. The lower portion outside the body 21 is extended downward evenly with three lock catches 24 of the catch head turning inside out. The lower of each lock catch 24 are higher than the lower of the lifting lever 23 . The upper of the insert portion 22 is a frustum 221 of polygon with 12 sides of slightly inside shrink. The upper surface of the frustum is disposed with a raised arrowhead 25 . The upper surface of the arrowhead 25 is painted a bright color to mark the orientation of the gap of the lifting lever 23 . A limited block 26 of projected outward, corresponding to the arrowhead 25 , is disposed in the lower of the periphery of the body 21 . Please refer to the FIG. 6 , FIG. 7 , FIG. 8 and FIG. 10 : the inner knob 20 is locked into the circle pipe shaped boss 42 on the housing 41 of the base set 40 . The body 21 of the inner knob 20 is above the boss 42 . The lifting lever 23 and the three lock catches are plugged into the pipe hole of the boss 42 . The catch head of each lock catch 24 is locked in the inner flange in the upper of the boss 42 . The lifting lever 23 is inserted into the groove in the upper of the thermoregulator base 45 . The gap in the lower of the lifting lever 23 is locked in the raise inside the groove of the thermoregulator base 45 to make the orientation of the lifting lever 23 is corresponding to the orientation of the level lever 46 of the thermoregulator, making sure the arrowhead 25 on the inner knob 20 is uniquely indicated the level of the thermoregulator. The limited block 26 of the inner knob 20 is cooperated with the cog 43 on the upper surface of the boss 42 to limit the rotation range of the inner knob, that is the limited of the level lever 46 rotating within the specified level position. Please refer to the FIG. 9 and the FIG. 10 : the steam brush set 30 is locked on the base set 40 , forming an iron with handle. The insert portion 22 of the inner knob 20 is inserted in the inner wall 13 of the axle sleeve of the external knob 10 . When rotating the disc 11 of the external knob 10 , the inner knob 20 , the thermoregulator base 45 and the level lever 46 of the thermoregulator are rotated synchronously. The arrowhead 25 on the inner knob 20 and the present level of the thermoregulator corresponding with the level scale on the housing 31 of the steam brush set 30 are read clearly through the disc 11 of the external knob 10 . The Second Embodiment The structure of the second embodiment of a biservice iron in break state is figured in the FIG. 11 . The biservice iron same as the prefer embodiment includes an independent steam brush set 30 and an independent base set 40 . A handle 32 is disposed on the housing 31 of the steam brush 30 for garment steaming. A steam boiler of electric heated is disposed inside the housing 31 of the steam brush set 30 . The steam outlet pipe of the steam boiler is connected to outside from the steam outlet portion 33 on the bottom of the housing 31 . The electric wire is led into the housing 31 from the rear portion and connected to the switch of the steam boiler. When turning on the switch, the steam boiler is energized by the external power. The water inside the steam boiler turns into steam and spurts out from the steam outlet portion 33 on the bottom of the housing 31 . An assembly portion 34 of circuit pipe shaped is disposed below the handle 32 on the housing 31 of the steam brush set 30 for the assembly of the external knob 10 . The front portion of the housing 31 of the steam brush set 30 is extended down with an insert head 36 . The two sides of the central portion of the housing 31 of the steam brush set 30 are extended down with an insert head 37 each. A catch groove is disposed at the rear of the housing 31 of the steam brush set 30 for holding the overturn catch head 491 . The rear portion on the lower surface of the housing 31 of the steam brush set 30 is disposed with an electrical outlet for energizing the base set 40 . The housing 41 of the base set 40 is disposed without a handle. The central of the housing 41 of the base set 40 is disposed with a concave accommodation room 48 to accommodate and catch the lower portion of the steam brush set 30 . The central of the accommodation room 48 is disposed with a circular pipe shaped boss 42 extending upward. The upper surface of the boss is disposed with an upward cog 43 . The heating pan 44 is disposed on the bottom of the housing 41 of the base set 40 . A thermoregulator is disposed inside the housing 41 to energize the heating pan 44 and then change the heat radiation of the heating pan 44 . The level lever 46 of the thermoregulator is disposed inside the boss 42 to rotatably connect to the inner knob 20 . The rear portion of the accommodation room 48 is disposed with an electrical plug 47 , which is cooperated with the electrical outlet of the housing 31 of the steam brush set 30 to receive the power from the steam brush set 30 and then energize the thermoregulator. The rear portion of the accommodation room 48 is disposed with an overturn catch head 491 , which is controlled by the lock knob 49 at the rear of the housing 41 of the base set 40 . Put the steam brush set 30 on the accommodation room 48 of the housing 41 of the base set 40 , the insert head 36 in the front of the housing 31 of the steam brush set 30 and the insert heads 37 on the two sides of the central of the housing 31 of the steam brush set 30 are separately withstanding the inner wall of the front and the two sides of the central portion of the accommodation room 48 . The electrical outlet on the lower surface of the housing 31 of the steam brush set 30 is cooperated with the electrical plug 47 at the rear portion of the accommodation room 48 . Rotate the lock knob 49 , making the overturn catch head 491 locked into the catch groove at the rear portion of the housing 31 of the steam brush set 30 , and then the steam brush set 30 is locked to the base set 40 , forming an iron with handle for ironing. The structure of the thermoregulator knob in break state of the embodiment is figured in the FIG. 12 . The thermoregulator knob is consisting of the external knob 50 and the inner knob 60 . Please refer to the FIG. 13 , FIG. 14 and FIG. 17 with combination with the FIG. 12 : The upper portion of the external knob 50 is a disc 51 with the opening downward. A circle boss is extended upwards from the central portion of the upper surface of the disc 51 . A circle short axis 52 is extended downward from the central of the lower surface of the disc 51 . The lower of the short axis 52 is an external cylinder 53 of polygon with 12 eaves. The external cylinder 53 is a conical surface of polygon with 12 eaves of slightly inside shrink. The lower surface of the disc 51 is located outside the short axis 52 and extended downward with three lock catches 55 evenly distributed in the peripheral direction. The catch head of every lock catch 55 is turning inside out. The distance between the root of the catch head of the lock catch 55 and the lower edge of the disc 51 is slightly bigger than the wall thickness of the inner flange of the steam brush set 30 according to the top of the assembly portion 34 . The length of every lock catch 55 is less than that of the short axis 52 , making sure that the external cylinder 53 of the short axis 52 is deep enough to insert into the insert hole 62 of the inner knob 50 . The external knob 50 is inserted into the assembly portion 34 on the housing 31 of the steam brush set 30 . The disc 51 in the upper portion of the external knob 50 is disposed above the assembly portion 34 . The short axis 52 and the three lock catches 55 are dipped into the pipe hole 35 inside the assembly portion 34 . The catch head of the three lock catches 55 are locked in the inner flange at the upper portion of the assembly portion 34 . The upper surface of the inner flange at the upper portion of the assembly portion 34 is printed with level scale of the thermoregulator. The level scale can be read clearly through the disc 51 of the external knob 50 . Please refer to the FIG. 15 , FIG. 16 and FIG. 17 with combination with the FIG. 12 : the central and the upper of the inner knob 60 is a circle pipe shaped body 61 , the upper surface of which is extended upward with an insert hole 62 with an interior cylinder of polygon with 12 eaves of slightly inside shrink. The size of the insert hole 62 is corresponding to the external cylinder 53 of the short axis 52 of the external knob 50 in inserted way. The central of the lower surface inside the body 61 is extended downward with an elongated lifting lever 63 . The lower portion of the lifting lever 63 is cut with a gap for orientation marker. The lower portion outside the body 61 is extended downward evenly with three lock catches 64 of the catch head turning inside out. The lower of each lock catch 64 is higher than the lower of the lifting lever 63 . The upper surface of the body 61 is disposed with a concave radial scratch 65 and three grooves 67 of evenly distribution in the periphery direction. The upper surface of the scratch 65 is painted a bright color to mark the orientation of the gap of the lifting lever 23 . A limited block 66 of projected outward, corresponding to the scratch 65 , is disposed in the lower of the periphery of the body 61 . The inner knob 60 is locked into the circle pipe shaped boss 42 on the housing 41 of the base set 40 . The body 61 of the inner knob 60 is above the boss 42 . The lifting lever 23 and the three lock catches 64 are plugged into the pipe hole of the boss 42 . The catch head of each lock catch 64 is locked in the inner flange in the upper of the boss 42 . The lifting lever 63 is inserted into the groove in the upper of the thermoregulator base 45 . The gap in the lower of the lifting lever 63 is locked in the raise inside the groove of the thermoregulator base 45 to make the orientation of the lifting lever 63 is corresponding to the orientation of the level lever 46 of the thermoregulator, making sure that the scratch 65 on the inner knob 60 is uniquely indicated the level of the thermoregulator. The limited block 66 of the inner knob 60 is cooperated with the cog 43 on the upper surface of the boss 42 to limit the rotation range of the inner knob. That is the limited of the level lever 46 rotating within the specified level position. The steam brush set 30 is locked on the base set 40 , forming an iron with handle. The external cylinder 53 of polygon with 12 eaves of the short axis 52 of the external knob 50 is inserted into the insert hole 62 of the inner knob 60 . When rotating the disc 51 of the external knob 50 , the inner knob 60 , the thermoregulator base 45 and the level lever 46 of the thermoregulator are rotated synchronously. The scratch 65 on the inner knob 60 and the present level of the thermoregulator corresponding with the level scale on the housing 31 of the steam brush set 30 are read clearly through the disc 61 of the inner knob 60 . Although the present invention has been described with reference to the preferred embodiments thereof for carrying out the invention, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims. INDUSTRIAL APPLICABILITY The present invention is provided with a biservice iron, in which the steam brush set and the base set are assemble or disassemble. The independent steam brush set is used for garment ironing or for providing hot steam. The steam brush set and the base set is assembled to be an iron. The present invention expands the usage mode of the iron.

The present invention of a biservice iron relates to an iron, especially an iron of which the steam brush and the base of the metal soleplate are disassembled. The present invention of a biservice iron includes a steam brush set, a base set and a thermoregulator knob. The thermoregulatory knob includes an external knob rotatably disposed on the housing of the steam brush set and an inner knob rotatably disposed on the housing of the base set. The inner knob is connected to the level lever of the thermoregulator on the housing of the base set. The external knob is inserted.

FIELD OF INVENTION This invention relates to an acidic light duty liquid cleaning composition which imparts mildness to the skin which can be in the form of a microemulsion designed in particular for cleaning hard surfaces and which is effective in removing particular and grease soil in leaving unrinsed surfaces with a shiny appearance. BACKGROUND OF THE INVENTION In recent years all-purpose light duty liquid detergents have become widely accepted for cleaning hard surfaces, e.g., dishes, glasses, sinks, painted woodwork and panels, tiled walls, wash bowls, washable wall paper, etc. Such all-purpose liquids comprise clear and opaque aqueous mixtures of water-soluble organic detergents and water-soluble detergent builder salts. The present invention relates to light duty liquid detergent compositions with high foaming properties, which contain a sulfonate surfactant and a hydroxy aliphatic acid. The prior art is replete with light duty liquid detergent compositions containing nonionic surfactants in combination with anionic and/or betaine surfactants wherein the nonionic detergent is not the major active surfactant, as shown in U.S. Pat. No. 3,658,985 wherein an anionic based shampoo contains a minor amount of a fatty acid alkanolamide. U.S. Pat. No. 3,769,398 discloses a betaine-based shampoo containing minor amounts of nonionic surfactants. This patent states that the low foaming properties of nonionic detergents renders its use in shampoo compositions non-preferred. U.S. Pat. No. 4,329,335 also discloses a shampoo containing a betaine surfactant as the major ingredient and minor amounts of a nonionic surfactant and of a fatty acid mono- or di-ethanolamide. U.S. Pat. No. 4,259,204 discloses a shampoo comprising 0.8-20% by weight of an anionic phosphoric acid ester and one additional surfactant which may be either anionic, amphoteric, or nonionic. U.S. Pat. No. 4,329,334 discloses an anionic-amphoteric based shampoo containing a major amount of anionic surfactant and lesser amounts of a betaine and nonionic surfactants. U.S. Pat. No. 3,935,129 discloses a liquid cleaning composition based on the alkali metal silicate content and containing five basic ingredients, namely, urea, glycerin, triethanolamine, an anionic detergent and a nonionic detergent. The silicate content determines the amount of anionic and/or nonionic detergent in the liquid cleaning composition. However, the foaming property of these detergent compositions is not discussed therein. U.S. Pat. No. 4,129,515 discloses a heavy duty liquid detergent for laundering fabrics comprising a mixture of substantially equal amounts of anionic and nonionic surfactants, alkanolamines and magnesium salts, and, optionally, zwitterionic surfactants as suds modifiers. U.S. Pat. No. 4,224,195 discloses an aqueous detergent composition for laundering socks or stockings comprising a specific group of nonionic detergents, namely, an ethylene oxide of a secondary alcohol, a specific group of anionic detergents, namely, a sulfuric ester salt of an ethylene oxide adduct of a secondary alcohol, and an amphoteric surfactant which may be a betaine, wherein either the anionic or nonionic surfactant may be the major ingredient. SUMMARY OF THE INVENTION It has now been found that an acid light duty liquid detergent can be formulated with an anionic surfactant which has desirable cleaning properties and mildness to the human skin. An object of this invention is to provide an acidic light duty liquid detergent composition which can be in the form of a microemulsion, and comprises a sulfate and/or sulfonate anionic surfactant and an organic acid, wherein the composition does not contain any N-alkyl aldonamide zwitterionic surfactant, silicas, abrasives, alkali metal carbonates, alkaline earth metal carbonates, alkyl glycine surfactant or a cyclic imidinium surfactant. Another object of this invention is to provide an acidic light duty liquid detergent with desirable high foaming and cleaning properties which kills bacteria. Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. DETAILED DESCRIPTION OF THE INVENTION The microemulsion light duty liquid compositions of the instant invention comprises approximately by weight: (a) 8% to 30% of an alkali metal salt of an anionic sulfonate surfactant; (b) 2% to 15% of an alkali metal salt of a C 8-18 ethoxylated alkyl ether sulfate and/or an C8-18 alkyl ether sulfate; (c) 0% to 10% of an ethoxylated nonionic surfactant; (d) 0 to 5% of polyethylene glycol; (e) 0.1% to 5% of an organic acid; (f) 0 to 10% of at least one solubilizing agent; (g) 0.5% to 14% of at least one cosurfactant; (h) 0 to 5% of an inorganic magnesium salt; (i) 0.5% to 8% of a water insoluble organic ester or a water insoluble material such as terpene or essential oils; (j) 0 to 2%, more preferably 0.05% to 2% of a thickener; and (k) the balance being water. The nonmicroemulsion light duty liquid compositions of the instant invention comprise approximately by weight: (a) 8% to 30% of an alkali metal salt of an anionic sulfonate surfactant; (b) 2% to 15% of an alkali metal salt of an C8-18 ethoxylated alkyl ether sulfate and/or a C8-18 alkyl ether sulfate; (c) 0% to 10% of an ethoxylated nonionics surfactant; (d) 0% to 8% of a water insoluble organic ester or a water insoluble material such as terpene or essential oils; (e) 0 to 5% of a polyethylene glycol; (f) 0 to 5% of an inorganic magnesium salt; (g) 0 to 10% of a solubilizer; (h) 0.1% to 5% of an organic acid; (i) 0 to 2%, more preferably 0.05% to 2% of a thickener; and (j) the balance being water. The instant compositions do not contain an N-alkyl aldonamide, choline chloride or buffering system which is a nitrogenous buffer which is ammonium or alkaline earth carbonate, guanidine derivates, alkoxylalkyl amines and alkyleneamines, which do not contain a hydroxy group, phosphoric acid, amino alkylene phosphonic acid and the composition is pourable and is not a gel and the composition has a complex viscosity at 1 rads-1 of less than 0.4 Pascal seconds. The anionic sulfonate surfactants which may be used in the detergent of this invention are water soluble and include the sodium, potassium, ammonium and ethanolammonium salts of linear C 8 -C 16 alkyl benzene sulfonates; C 10 -C 20 paraffin sulfonates, alpha olefin sulfonates containing about 10-24 carbon atoms and C 8 -C 18 alkyl sulfates and mixtures thereof. The preferred anionic sulfonate surfactant is a C 12-18 paraffin sulfonate. The paraffin sulfonates may be monosulfonates or di-sulfonates and usually are mixtures thereof, obtained by sulfonating paraffins of 10 to 20 carbon atoms. Preferred paraffin sulfonates are those of C 12-18 carbon atoms chains, and more preferably they are of C 14-17 chains. Paraffin sulfonates that have the sulfonate group(s) distributed along the paraffin chain are described in U.S. Pat. Nos. 2,503,280; 2,507,088; 3,260,744; and 3,372,188; and also in German Patent 735,096. Such compounds may be made to specifications and desirably the content of paraffin sulfonates outside the C 14-17 range will be minor and will be minimized, as will be any contents of di- or poly-sulfonates. Examples of suitable other sulfonated anionic detergents are the well known higher alkyl mononuclear aromatic sulfonates, such as the higher alkylbenzene sulfonates containing 9 to 18 or preferably 9 to 16 carbon atoms in the higher alkyl group in a straight or branched chain, or C 8-15 alkyl toluene sulfonates. A preferred alkylbenzene sulfonate is a linear alkylbenzene sulfonate having a higher content of 3-phenyl (or higher) isomers and a correspondingly lower content (well below 50%) of 2-phenyl (or lower) isomers, such as those sulfonates wherein the benzene ring is attached mostly at the 3 or higher (for example 4, 5, 6 or 7) position of the alkyl group and the content of the isomers in which the benzene ring is attached in the 2 or 1 position is correspondingly low. Preferred materials are set forth in U.S. Pat. No. 3,320,174, especially those in which the alkyls are of 10 to 13 carbon atoms. The C 8-18 ethoxylated alkyl ether sulfate surfactants have the structure R--(OCHCH.sub.2).sub.n OSO.sub.3.sup.- M.sup.+ wherein n is about 1 to about 22 more preferably 1 to 3 and R is an alkyl group having about 8 to about 18 carbon atoms, more preferably 12 to 15 and natural cuts, for example, C 12-14 or C 12-16 and M is an ammonium cation or a metal cation, most preferably sodium. The ethoxylated alkyl ether sulfate may be made by sulfating the condensation product of ethylene oxide and C 8-10 alkanol, and neutralizing the resultant product. The ethoxylated alkyl ether sulfates differ from one another in the number of carbon atoms in the alcohols and in the number of moles of ethylene oxide reacted with one mole of such alcohol. Preferred ethoxylated alkyl ether polyethenoxy sulfates contain 12 to 15 carbon atoms in the alcohols and in the alkyl groups thereof, e.g., sodium myristyl (3 EO) sulfate. Ethoxylated C 8-18 alkylphenyl ether sulfates containing from 2 to 6 moles of ethylene oxide in the molecule are also suitable for use in the invention compositions. These detergents can be prepared by reacting an alkyl phenol with 2 to 6 moles of ethylene oxide and sulfating and neutralizing the resultant ethoxylated alkylphenol. The concentration of the ethoxylated alkyl ether sulfate surfactant is about 2 to about 15 wt. %. The compositions of the present invention may contain a nonionic surfactant or mixtures thereof. Suitable nonionic surfactants for use herein are fatty alcohol ethoxylates which are commercially available with a variety of fatty alcohol chain lengths and a variety of ethoxylation degrees. Indeed, the HLB values of such nonionic surfactants depend essentially on the chain length of the fatty alcohol and the degree of ethoxylation. Particularly suitable nonionic surfactants are the condensation products of a higher aliphatic alcohol containing about 8 to 18 carbon atoms in a straight or branched chain configuration, condensed with about 2 to 30 moles of ethylene oxide. The organic acid is used in the nonmicroemulsion or microemulsion composition at a concentration of about 0.1 wt. % to about 5 wt. %, more preferably about 0.5 wt. % to about 4 wt. %. The organic acid used in the instant composition is selected from the group consisting of malonic acid, fumaric acid, glutaric acid, succinic acid, benzoic acid and ascorbic acid and mixtures thereof. The thickener is used at a concentration of 0 to about 2 wt. %, more preferably about 0.05 wt. % to about 2 wt. %. A preferred polymeric thickener is a sodium salt of a polyacrylic acid having a molecular weight of 500000 such as Acusol 820 sold by ROHM & HAAS. Other thickeners which could be used are cellulose, hydroxypropyl cellulose, polyacrylate polyacrylamides and polivilyl alcohol. The water insoluble saturated organic diester has the formula: ##STR1## wherein R 1 and R 2 are independently a C 2 to C 6 alkyl group and n is a number from 4 to 8. A preferred organic diester is dibutyl adipate. The concentration of the organic diester in the microemulsion composition is about 0.5 wt. % to about 8 wt. %, more preferably about 1 wt. % to about 6 wt. %. Among components of different types of perfumes that may be employed are the following: essential oils--pine, balsam, fir, citrus, evergreen, jasmine, lily, rose and ylang ylang; esters--phenoxyethyl isobutyrate, benzyl acetate, p-tertiary butyl cyclohexyl acetate, guaiacwood acetate, linalyl acetate, dimethylbenzyl carbinyl acetate, phenylethyl acetate, linalyl benzoate, benzyl formate, ethylmethylphenyl glycidate, allylcyclohexane propionate, styrallyl propionate and benzyl salicylate; ethers--benzyl-ethyl ether; aldehydes--alkyl aldehydes of 8 to 18 carbon atoms, bourgeonal, citral, citronellal, citronellyl oxyacetaldehyde, cyclamen aldehyde, hydroxycitronellal and lilial; alcohols--anethol, citronellol, eugenol, geraniol, linalool, phenylethyl alcohol and terpineol; hydrocarbons--balsams and terpenes; ketones--ionones, alpha-isomethyl ionone, and methylcedryl ketone; lactones--gamma-alkyl lactone wherein the alkyl is of 8 to 14 carbon atoms; pyrrones--hydroxy-lower alkyl pyrrone wherein the alkyl is of 1 to 4 carbon toms; and pyrroles--benzopyrrole. While various components of perfumes that are considered to be useful in the invented composition have been described above, the particular composition of the perfume is not considered to be critical with respect to cleaning properties so long as it is water insoluble (and has an acceptable fragrance). For use by the housewife or other consumer in the home, the perfume, as well as all other components of these cleaners, should be cosmetically acceptable, i.e., non-toxic, hypoallergenic, etc. The polyethylene glycol used in the instant composition has a molecular weight of 200 to 1,000, wherein the polyethylene glycol has the structure HO(CH.sub.2 CH.sub.2 O).sub.n H wherein n is 4 to 25. The concentration of the polyethylene glycol in the instant composition is 0 to 5 wt. %, more preferably 0.1 wt. % to 4 wt. %. The instant light duty liquid nonmicroemulsion compositions contain about 0 wt. % to about 10 wt. %, more preferably about 1 wt. % to about 8 wt. %, of at least one solubilizing agent selected from the group consisting of a C 2-5 mono, dihydroxy or polyhydroxy alkanols such as ethanol, isopropanol, glycerol ethylene glycol, diethylene glycol and propylene glycol and mixtures thereof and alkali metal cumene or xylene sulfonates such as sodium cumene sulfonate and sodium xylene sulfonate. The solubilizing agents are included in order to control low temperature cloud clear properties. The cosurfactant used in the microemulsion composition may play an essential role in the formation of the microemulsion compositions. Very briefly, in the absence of the cosurfactant the water, detergent(s) and hydrocarbon (e.g., perfume) will, when mixed in appropriate proportions form either a micellar solution (low concentration) or form an oil-in-water emulsion in the first aspect of the invention. With the cosurfactant added to this system, the interfacial tension at the interface between the emulsion droplets and aqueous phase is reduced to a very low value. This reduction of the interfacial tension results in spontaneous break-up of the emulsion droplets to consecutively smaller aggregates until the state of a transparent colloidal sized emulsion. e.g., a microemulsion, is formed. In the state of a microemulsion, thermodynamic factors come into balance with varying degrees of stability related to the total free energy of the microemulsion. Some of the thermodynamic factors involved in determining the total free energy of the system are (1) particle-particle potential; (2) interfacial tension or free energy (stretching and bending); (3) droplet dispersion entropy; and (4) chemical potential changes upon formation. A thermodynamically stable system is achieved when (2) interfacial tension or free energy is minimized and (3) droplet dispersion entropy is maximized. Thus, the role of cosurfactant in formation of a stable o/w microemulsion is to (a) decrease interfacial tension (2); and (b) modify the microemulsion structure and increase the number of possible configurations (3). Also, the cosurfactant will (c) decrease the rigidity. Generally, an increase in cosurfactant concentration results in a wider temperature range of the stability of the product. The major class of compounds found to provide highly suitable cosurfactants for the microemulsion over temperature ranges extending from 5° C. to 43° C. for instance are polypropylene glycol of the formula HO(CH 3 CHCH 2 O) n H wherein n is a number from 1 to 18, and mono and di C 1 -C 6 alkyl ethers and esters of ethylene glycol and propylene glycol having the structural formulas R(X) n OH, R 1 (X) n OH, R(X) n OR and R 1 (X) n OR 1 wherein R is C 1 -C 6 alkyl group, R 1 is C 2 -C 4 acyl group, X is (OCH 2 CH 2 ) or (OCH 2 (CH 3 )CH) and n is a number from 1 to 4, diethylene glycol, triethylene glycol, an alkyl lactate, wherein the alkyl group has 1 to 6 carbon atoms, 1 methoxy-2-propanol, 1 methoxy-3-propanol, and 1 methoxy 2-, 3- or 4-butanol. Representative members of the polypropylene glycol include dipropylene glycol and polypropylene glycol having a molecular weight of 150 to 1000, e.g., polypropylene glycol 400. Other satisfactory glycol ethers are ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol monobutyl ether, mono, di, tri propylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, mono, di, tripropylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, propylene glycol tertiary butyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monopropyl ether, ethylene glycol monopentyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monopentyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monopentyl ether, triethylene glycol monohexyl ether, mono, di, tripropylene glycol monoethyl ether, mono, di tripropylene glycol monopropyl ether, mono, di, tripropylene glycol monopentyl ether, mono, di, tripropylene glycol monohexyl ether, mono, di, tributylene glycol mono methyl ether, mono, di, tributylene glycol monoethyl ether, mono, di, tributylene glycol monopropyl ether, mono, di, tributylene glycol monobutyl ether, mono, di, tributylene glycol monopentyl ether and mono, di, tributylene glycol monohexyl ether, ethylene glycol monoacetate and dipropylene glycol propionate. When these glycol type cosurfactants are at a concentration of about 0.5 to about 14 weight %, more preferably about 2.0 weight % to about 10 weight % in combination with a water insoluble organic ester or non water soluble material such as terpene, essential oils which is at a concentration of at least 0.5 weight %, more preferably 1.5 weight % to about 8 wt. % one can form a microemulsion composition. While all of the aforementioned glycol ether compounds provide the described stability, the most preferred cosurfactant compounds of each type, on the basis of cost and cosmetic appearance (particularly odor), are dipropylene glycol monomethyl ether and propylene glycol. Other suitable water soluble cosurfactants are water soluble esters such as ethyl lactate and water soluble carbohydrates such as butyl glycosides. The instant microemulsion formulas explicitly exclude alkali metal silicates and alkali metal builders such as alkali metal polyphosphates, alkali metal carbonates and alkali metal phosphonates because these materials, if used in the instant composition, would cause the composition to have a high pH as well as leaving residue on the surface being cleaned. The final essential ingredient in the inventive microemulsion or nonmicroemulsion compositions having improved interfacial tension properties is water. The proportion of water in the compositions generally is in the range of 35% to 90%, preferably 50% to 85% by weight of the usual diluted o/w microemulsion composition. In addition to the above-described essential ingredients required for the formation of the microemulsion composition, the compositions of this invention may often and preferably do contain one or more additional ingredients which serve to improve overall product performance. One such ingredient is an inorganic or organic salt of oxide of a multivalent metal cation, particularly Mg ++ . The metal salt or oxide provides several benefits including improved cleaning performance in dilute usage, particularly in soft water areas, and minimized amounts of perfume required to obtain the microemulsion state. Magnesium sulfate, either anhydrous or hydrated (e.g., heptahydrate), is especially preferred as the magnesium salt. Good results also have been obtained with magnesium oxide, magnesium chloride, magnesium acetate, magnesium propionate and magnesium hydroxide. These magnesium salts can be used with formulations at neutral or acidic pH since magnesium hydroxide will not precipitate at these pH levels. Although magnesium is the preferred multivalent metal from which the salts (inclusive of the oxide and hydroxide) are formed, other polyvalent metal ions also can be used provided that their salts are nontoxic and are soluble in the aqueous phase of the system at the desired pH level. Thus, depending on such factors as the pH of the system, the nature of the primary surfactants and cosurfactant, and so on, as well as the availability and cost factors, other suitable polyvalent metal ions include aluminum, copper, nickel, iron, calcium, etc. It should be noted, for example, that with the preferred paraffin sulfonate anionic detergent calcium salts will precipitate and should not be used. It has also been found that the aluminum salts work best at pH below 5 or when a low level, for example 1 weight percent, of citric acid is added to the composition which is designed to have a neutral pH. Alternatively, the aluminum salt can be directly added as the citrate in such case. As the salt, the same general classes of anions as mentioned for the magnesium salts can be used, such as halide (e.g., bromide, chloride), sulfate, nitrate, hydroxide, oxide, acetate, propionate, etc. Preferably, in the dilute compositions the metal compound is added to the composition in an amount sufficient to provide at least a stoichiometric equivalent between the anionic surfactant and the multivalent metal cation. For example, for each gram-ion of Mg++ there will be 2 gram moles of paraffin sulfonate, alkylbenzene sulfonate, etc., while for each gram-ion of A1 3+ there will be 3 gram moles of anionic surfactant. Thus, the proportion of the multivalent salt generally will be selected so that one equivalent of compound will neutralize from 0.1 to 1.5 equivalents, preferably 0.9 to 1.4 equivalents, of the acid form of the anionic surfactant. At higher concentrations of anionic surfactant, the amount of the inorganic magnesium salt will be in range of 0 to 5 wt. %, more preferably 0.5 to 3 wt. %. The liquid cleaning composition of this invention may, if desired, also contain other components either to provide additional effect or to make the product more attractive to the consumer. The following are mentioned by way of example: Colors or dyes in amounts up to 0.5% by weight; preservatives or antioxidizing agents, such as formalin, 5-bromo-5-nitro-dioxan-1,3; 5-chloro-2-methyl-4-isothaliazolin-3-one, 2,6-di-tert.butyl-p-cresol, etc., in amounts up to 2% by weight; and pH adjusting agents, such as sulfuric acid or sodium hydroxide, as needed. Furthermore, if opaque compositions are desired, up to 4% by weight of an opacifier may be added. In final form, the instant compositions exhibit stability at reduced and increased temperatures. More specifically, such compositions remain clear and stable in the range of 5° C. to 50° C., especially 10° C. to 43° C. Such compositions exhibit a pH of 3 to 7.0. The liquid microemulsion compositions are readily pourable and exhibit a viscosity in the range of 6 to 400 milliPascal.second (mPas.) as measured at 25° C. with a Brookfield RVT Viscometer using a #2 spindle rotating at 50 RPM. The following examples illustrate liquid cleaning compositions of the described invention. Unless otherwise specified, all percentages are by weight. The exemplified compositions are illustrative only and do not limit the scope of the invention. Unless otherwise specified, the proportions in the examples and elsewhere in the specification are by weight. EXAMPLE 1 The following compositions in wt. % were prepared by simple mixing procedure: __________________________________________________________________________ A B C D E F__________________________________________________________________________C.sub.14-16 paraffin sulfonates sodium salt 21.33 21.33 21.33 21.33 21.33 21.33C.sub.13-14 AEOS 2:1 EO 10.67 10.67 10.67 10.67 10.67 10.67Polyethylene glycol MN300 1.5 1.5 1.5 1.5 1.5 1.5MgSO47H2O 2 2 2 2 2 2Dipropylene glycol monobutyl ether 1 1 1 1 1 1Malonic acid 2Fumaric acid 0.4Glutaric acid 2Succinic acid 2Benzoic acid 0.34Ascorbic acid 2Perfume 0.4 0.4 0.4 0.4 0.4 0.4Water Bal. Bal. Bal. Bal. Bal. Bal.Appearance @ RT Clear Clear Clear Clear Clear ClearAppearance @ 4° C. Clear Clear Clear Clear Cloudy ClearpH 2.6 3.5 4 3.6 5.6 3.95Viscosity (RVT, 50 rmp, spd2) 376 432 320 360 216 464__________________________________________________________________________

A light duty liquid detergent with desirable cleansing properties to the human skin comprising a C 8-18 ethoxylated alkyl ether sulfate anionic surfactant, a sulfonate anionic surfactant, an organic acid and water.

BACKGROUND [0001] The invention is in the field of medical treatments generally and patient vascular access systems. The present invention relates to embodiments for detecting blood leakage during extracorporeal blood treatment or other medical procedure. [0002] The maxim of “first, do no harm,” may be a good summary of the Hippocratic oath required of doctors and practiced by medical professionals. Nowhere is this principle required more than in modern medicine. With patients living longer, there are more extended treatments and more frail patients than ever. Such patients are in danger from complications that can arise from continuing therapeutic procedures, and even from diagnostic procedures, that are necessary for their continued care. Treatments involving extra-corporeal blood treatment are clear examples. [0003] The most obvious danger is infection, but the harm caused by infection can be overcome by not re-using even supposedly-sterile devices and by diligent attention by the patient himself or herself, and by care givers attending to the patient. Other dangers also arise, but, like infections, have been difficult to eradicate. One of these dangers arises in blood treatment procedures in which the blood of a patient is physically removed from the patient for treatment, and then returned, all in the same procedure. Removal and return of blood is practiced in hemodialysis, for those persons whose kidneys do not function well. Other procedures, such as apheresis, involve removing blood from a patient or a donor to separate blood platelets or plasma from the red blood cells and then returning the red blood cells to the patient or donor, as described in U.S. Pat. Nos. 5,427,695 and 6,071,421. [0004] The extracorporeal medical treatments described above require that the blood be removed for treatment and then returned. This requires access to the patient's vascular system, from which blood is removed and to which blood is then returned. If a “batch” treatment is used, that is, a quantity of blood is withdrawn, treated and returned, only a single needle is used. Each batch of such treatment is typically short, and the treatment is attended by a medical professional at a clinic or hospital. A variation on the batch treatment is a “batch” continuous method in which only a single needle is used. There are distinct withdraw and return phases in a batch continuous process. During the draw phase, blood is processed and additional blood is sent to a holding container to be processed during the return phase. In the return phase, blood is processed from the holding container and then returned to the patient or donor through the single needle. Other treatments are continuous, such as the platelet separation discussed above, or dialysis treatment, and may require a duration of several hours or even overnight. [0005] Continuous treatments require two needles, or access points, one for withdrawal of blood and one for return. The withdrawal site is normally an artery or an arteriovenous fistula/graft, and a needle and a pump are used to provide the blood to the therapeutic machine. It is relatively simple to detect a problem with withdrawal, for instance, if the withdrawal needle is dislodged, using conventional air sensor technology. Detecting a problem in the return of the blood to the patient is more difficult. The return line typically includes a needle with venous access. If the return line is dislodged, the blood is not returned to the patient's vascular system, but may continue to be pumped and may accumulate near the patient. Depending on the pumping rate of the blood and the time for treatment, this could have life-threatening effects on the patient within a very short period of time. [0006] Accordingly, a number of apparatuses have been devised for detecting needle dislodgement, especially venous needle dislodgement. An example is U.S. Pat. Appl. Publ. 2006/0130591. In a device according to this application, a venous needle is equipped with a photosensor and is covered with an opaque patch. This device would not send a signal or an alarm if the needle begins leaking or is only slightly dislodged. For example, the photosensor could still fail to detect light because the needle has not been dislodged sufficiently to expose the photosensor to light. In addition, this method requires ambient light and would thus not be suitable for patients that cover their arm with a blanket or who perform nocturnal dialysis while sleeping in a dark bedroom. [0007] Numerous other techniques have been devised, many of them depending on a flow of blood causing conductivity between two electrodes or two wires. What is needed is a better way of quickly detecting dislodgement of a venous or other needle from a patient, so that inadvertent loss of blood and harm to the patient is avoided. SUMMARY [0008] One embodiment is an accelerometer-based access disconnect detector. The detector includes an accelerometer configured for mounting on a patient near an access site, signal processing circuitry, the signal processing circuitry operably connected to the accelerometer for receiving indications from the accelerometer, and a controller configured for receiving readings from the signal processing circuitry and for sending a signal upon a change in the readings, wherein the controller is in communication with or is part of a therapy machine for receiving blood and returning blood to a patient. [0009] Another embodiment is an access disconnect detector. The detector includes a sensor for determining a flow of blood in a vein of a patient, the blood being returned from an extracorporeal blood therapy and the sensor configured for mounting on the patient near an access site, signal processing circuitry, the circuitry operably connected to the sensor for determining a flow rate of blood being returned from the extracorporeal therapy, and a communications circuit connected to the signal processing circuitry, wherein the sensor is configured for sensing the flow rate of blood through the vein and for generating readings indicative of the flow, and the signal processing circuitry is configured for receiving the readings and sending the readings to the communications circuit. [0010] Another embodiment is a method for detecting an access disconnection. The method includes steps of mounting a sensor on a patient near an access site, establishing a baseline sensor reading of the patient, detecting readings indicative of a pulsatile flow of blood with the sensor, comparing additional readings during an extracorporeal blood therapy with the readings indicative of pulsatile flow, deciding whether the additional readings are significantly different from the readings of pulsatile flow, and sending a signal if the sensor readings are significantly different from the readings of pulsatile flow. [0011] Another embodiment is a sensor-based method for detecting blood flow. The method includes steps of mounting a sensor indicative of blood flow to a patient near an access site, detecting first readings from the sensor indicative of a flow of blood from a pulsing mechanical pump, beginning an extracorporeal therapy with the patient, monitoring additional readings from the sensor during the therapy, deciding whether the additional readings are different from the first readings, and sending an alert if the readings are different from the first readings. [0012] Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures. BRIEF DESCRIPTION OF THE FIGURES [0013] FIG. 1 is a prior art view of an access site on a patient; [0014] FIG. 2 is a schematic view of a first embodiment of an access disconnect system; [0015] FIG. 3 is a schematic view of a control system for access disconnect detection; [0016] FIGS. 4-6 depict embodiments with an accelerometer sensor; [0017] FIG. 7 is a flowchart depicting a method of using an accelerometer at an access site; [0018] FIG. 8 depicts embodiments with a Doppler flow sensor; and [0019] FIG. 9 is a flowchart depicting a method of using a Doppler flow sensor. DETAILED DESCRIPTION [0020] As noted, it is important to detect a needle disconnect from an access site as soon as possible after it has happened. Embodiments of the present invention are useful for monitoring an access site in which a patient receives extracorporeal blood therapy, such as a person undergoing hemodialysis with a hemodialysis machine. An example of such a situation is depicted in FIG. 1 , which depicts a patient P undergoing hemodialysis with a hemodialysis machine H. The patient is connected to the hemodialysis machine with tubing lines L connected to an arterial access site A and a venous access site V. Venous access site needle V n is depicted. Other extracorporeal treatments are also contemplated, such as apheresis. [0021] A first embodiment of an access disconnect detection system is disclosed in FIGS. 2-3 . The embodiment in FIG. 2 is a sensor and its associated circuitry for placement on the patient near or adjacent the access site, that is, near or adjacent the venous needle insertion point, usually on an arteriovenous fistula site. The sensor 21 includes or is operably connected to an analog-to-digital converter (ADC) 22 and to further signal processing 23 , which may convert the digital data to a preferred format for transmission via communications module 25 . The communications module 25 is a wireless module with an antenna 26 , as shown. In other embodiments, the communications module is connected for further processing via a cord or wire 27 . [0022] The data is received at a communications module 31 of a receiver circuit 30 . This circuit may be in communication with, or may itself be part of, a therapy machine, such as a hemodialysis machine. Communications module 31 may be a wireless transmitter/receiver with an antenna 32 . The receiver circuit includes a microcontroller 33 and a memory 34 . Memory 34 may include a computer program and a look-up table for values of sensor readings and the proper steps to take according to the reading. The microcontroller and memory include circuitry and logic sufficient to receive signals from the sensor and the signal processing module and to receive, process and interpret those signals. The microprocessor also includes sufficient logic, in the form of software on a computer readable medium, to interpret the sensor data and to use the look up table to determine whether the readings suggest that the flow of blood has slowed, slowed to a great extent, or has stopped. [0023] One possible step to take, if the sensor reading so indicates, is to send a signal, such as an alarm using a local output device, such as a video screen 35 or a speaker 36 . This will alert the patient or a caregiver that a blood leak has been detected or that the needle may have become disconnected from the access site. The receiver may also send a signal through the communications module to a remote computer, such as a hospital or clinic information system, or to so send an alert to other personnel or to other sites. [0024] Accelerometer Application [0025] The sensor contemplated in one embodiment is an accelerometer. An accelerometer is a device for measuring external force. In this instance, the force is the pulsatile force of the patient's blood returning to the patient through the fistula. The accelerometer will sense the vibrations of the pulsed flow, at about the rate of the pump which is pumping the blood. This is typically a peristaltic pump rotating at about ______ beats per minute to about ______ beats per minute. Other mechanical pumps may be used, such as shuttle pumps or linear drive pumps. Even though this rate is close to a normal heartbeat of from about 50 to about 85 beats per minute, it is easily distinguished, because the accelerometer is mounted within 1-2 cm of the access site, and thus the vein into which the blood is being returned. Accordingly, the signal from the flow into the vein from the therapy machine is expected to be significantly stronger than the beat of the heart of the patient, which is more remote from the access site. [0026] A number of accelerometers are available from many manufacturers, such as Measurement Specialties, Inc., Hampton, Va., and Endevco Corp., San Juan Capistrano, Calif. One example is Model 40366 from Endevco. This is a microelectronic mechanical systems, capacitance-type accelerometer, including a very small mass and size, less than a cube 3 mm on a side. Such accelerometers are very small and lightweight, and may be assembled and mounted with some or all of the circuitry discussed above. In one embodiment, the accelerometer and at least some of the circuitry is mounted on the patient using medically-acceptable adhesive, such as a cyanoacrylate. In other embodiments, the accelerometer is part of a housing or detector that is taped to the patient's arm or other area, so that the accelerometer is suitably near the access site and can detect the vibrations of the pulsating flow of the returning blood. [0027] The signal processing circuitry and wireless transmitter are small and compact, and are easily placed on the patient at the access site. One signal module that fits the needs for this application is a wireless module in accord with ZigBee/IEEE 805.15.4. This is a standard for a very low power radio system with a very limited range, about 10-20 feet. Modules made in accordance with this standard may be purchased from Maxstream, Inc., Lindon, Utah, U.S.A., Helicomm, Inc., Carlsbad, Calif., U.S.A., and ANT, Cochrane, Alberta, Canada. The module is very small, and may be about 2 cm square (about 1 inch square), and about 3 mm thick (⅛ inch). One or more sensors are connected to the module. The module in FIG. 2 includes an analog-to-digital (ADC) converter to convert analog data from the sensor into digital data. The digital data is thus formatted when it is routed to a data buffer before wireless transmission or conveying via cable to a remote site. The remote site can be a nearby table within a few feet of the patient, or the hemodialysis machine, or a communications portion of the hemodialysis machine in the same room with the patient. [0028] Embodiments of the accelerometer sensor and a blood flow detector using the sensor are depicted in FIGS. 4-6 . In FIG. 4 , an accelerometer 41 is placed into a housing 40 for easier and steady placement on a patient. The accelerometer is placed near an edge of the housing so that the accelerometer may be as close as possible to the return vein of the access site. The housing may be a flexible silicone pad, or other conformable material that is not irritating to the patient. The sensor is connected by cord 42 to a receiver module 43 . Cord 42 may only be one or two feet long (30-60 cm) so that the receiver module 43 may be placed in a shirt or pajama pocket of the patient. [0029] Receiver module 43 may include a battery to power the accelerometer signal conversion circuits, and may also include a microcontroller and sufficient logic and memory to convert and analyze the signals sent from the accelerometer. Receiver module 43 may itself have a communications module with a wireless capability. The receiver module and microcontroller have the capability to communicate with the hemodialysis machine or other therapy machine, or with another receiver circuit or controller in operable communication with the therapy machine. Upon detecting cessation of the flow of blood, or a significant lessening of the flow, the microcontroller may send a signal. The signal may order the therapy to be ceased, may order an alarm to be sounded on a local output, or may send an alert to the patient or to a caregiver. [0030] Another embodiment is presented in FIGS. 5-6 . In these figures, the sensor and the housing 40 are used in conjunction with an arm band 44 having hook-and-loop fastener strips 45 . These strips are available under the trade name Velcro®. The receiver module 43 is mounted on outside of the arm band 44 and may use a clip 46 . On the patient's arm near the access site, housing 40 is secured over the venous access site V with an additional securing bandage 54 . In other embodiments, the housing may be firmly secured to the access site with tape. [0031] A method of using the accelerometer is depicted in the flowchart of FIG. 7 . In a first step of the method, an accelerometer is furnished 71 , along with circuitry to convert the sensor data, typically analog signals, into usable digital data. Other embodiments may simply use analog data, since no conversion to digital is strictly required, although it is customary. The accelerometer is mounted 72 near the venous access site, so that the readings of blood movement are clearly discernable. Baseline readings are taken 73 , typically with both no flow and with normal return blood flow in order to calibrate the accelerometer and to orient the microcontroller or other logic circuit with what are normal and non-normal blood flows. [0032] After therapy has begun, the accelerometer is monitored 74 to determine whether the sensor readings are consistent with normal blood flow. If the sensor readings are inconsistent with the expected flow, the microcontroller or other logic-device sends 75 a signal. As noted above, the signal may be a signal to cease therapy 76 , or may be a signal to raise alert or to send an alarm through a local output device, such as a video screen or a speaker. There are other embodiments using an accelerometer to detect blood flow, and this description is not intended to limit the embodiments. [0033] Flow Sensor Application [0034] Another sensor option is to use an ultrasound probe, such as a Doppler flow sensor, to detect blood flow in the vein receiving the blood. The Doppler probe is mounted on the patient's arm, near or preferably atop the vein receiving the blood. The Doppler will detect the blood flow, and if access disconnect occurs, the sensing signals will cease or change. Software or logic in a controller for the sensor or in the therapy machine will note the change. If the change is sufficient to suggest that corrective action should be taken, the microcontroller or other circuitry sends a signal to alert a caregiver or to cease pumping blood from the patient. [0035] Doppler sensors are made by many manufacturers, including Parks Medical Electronics, Las Vegas, Nev., including pencil probes. Probes are also available from Vascular Technology, Inc., Nashua, N.H. Probes at nominal frequencies of 4 and 8 MHz are recommended for vascular applications. The probe sends ultrasonic waves through the blood vessel and then receives back the reflected waves. Circuitry then generates signals indicative of the speed of the blood. In the case of venous access sites, time-averaging of the signals will likely be necessary because of the pulsing nature of the flow into the patient. When the indicated flow slows significantly or drops off completely, the controller monitoring the Doppler sensor will alert the user or a caregiver by sending a signal indicating the change in flow. [0036] Note that by sensing the actual vein and detecting and measuring blood flow, other conditions can also be discovered. For instance, in placing the needle into the access site, typically an arteriovenous fistula, it is possible to place the needle entirely through the vein, that is, to create an infiltration. With such an infiltration, a significant portion of the blood may not flow through the vein, but will instead enter the body in the area around the vein. If the sensor is placed even a small amount downstream of the access site or fistula, it is possible to detect the difference at least between this flow and previous flows, or between this flow and the flow of blood from the patient. Thus, a flow sensor can be used to detect infiltration. [0037] One embodiment of a monitor with a Doppler sensor is depicted in FIG. 8 . In this embodiment, a detector 80 includes a butterfly housing 81 with a Doppler sensor 82 is located on the underside of the housing. The housing is intended for mounting near the access site of a patient, and again, the sensor is placed near a periphery of the housing so that it can be placed as close as possible over the return vein or access site of the patient. The sensor is attached via cord 83 to a receiver circuit 84 . A clip 85 is furnished to clip the receiver housing to a shirt pocket of the user. In another embodiment, the detector 80 is equipped with a power source and with sufficient signal processing capability that receiver circuit 86 can be mounted wirelessly on the patient's other arm, using a wristband 87 and Velcro® securing strips 88 . [0038] The method of using the Doppler sensor is similar to the manner of use of the accelerometer. The method is depicted in the flowchart of FIG. 9 . In a first step of the method, a Doppler is furnished 91 , along with circuitry to convert the sensor data, typically analog signals, into usable digital data. Other embodiments may simply use analog data, since no conversion to digital is strictly required, although it is customary. The Doppler sensor is mounted 92 near the venous access site, so that the readings of blood movement and flow are clearly discernable. Baseline readings are taken 93 , typically with both no flow and with normal return blood flow in order to calibrate the Doppler sensor and to orient the microcontroller or other logic circuit with what are normal and non-normal blood flows. [0039] After therapy has begun, the Doppler sensor is monitored 94 to determine whether the sensor readings are consistent with normal, pulsed blood flow. If the sensor readings are inconsistent with the expected flow, the microcontroller or other logic-device sends 95 a signal. As noted above, the signal may be a signal to cease therapy 96 , or may be a signal to raise alert or to send an alarm through a local output device, such as a video screen or a speaker. There are other embodiments using a Doppler sensor to detect blood flow, and this description is not intended to limit the embodiments. [0040] One embodiment includes computer software that controls the therapy machine, such as a hemodialysis machine. The machine may be programmed so that the therapy cannot begin until the accelerometer or Doppler sensor and its expected reading is detected and are within the normal range. That is, the therapy machine or device is interlocked so that the therapy or procedure cannot begin until the required signals from the sensor or sensors are received. [0041] The embodiments described above have been specific in that certain mounts or housings are associated with one sensor or another, such as an accelerometer and flow sensor. It is understood that the sensors may be used with any suitable housing, rather than merely the housing described as particularly suited for a sensor. In addition, most of the sensors have been described as suitable for detecting and measuring venous flow. There is no reason these sensors, and their housings, if any, cannot be used for arterial blood flow. Comparison of arterial blood flow and venous blood flow can lead one to detect infiltration, that is, a puncture of the arteriovenous fistula. There are many other ways to use the sensors and methods described herein. [0042] 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 subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

Techniques are disclosed for monitoring the flow of blood returning to a patient from an extracorporeal therapy machine, such as a hemodialysis machine or an apheresis machine. Blood returning from such a machine is pumped, typically by a peristaltic pump, which returns the blood in pulsed flow or pulses. This flow can be sensed by Doppler flow sensors or accelerometers as it returns to the patient. If the flow is interrupted by dislodgement of the venous access needle, or by leaking of blood from the needle, these sensors will detect significantly different flow or vibrations. A controller can then cease therapy, alert a caregiver, or sound an alarm.

BACKGROUND [0001] Hydraulic fracturing is a common and well-known enhancement method for stimulating the production of hydrocarbons and natural gas in particular. The process involves injecting fluid down a wellbore at high pressure. The fracturing fluid is typically a mixture of water, proppant, and chemicals to improve the process. The chemicals improve the fracturing process in many ways such as by allowing the water to carry sufficient proppant to the desired locations. Other chemicals such as friction reducers reduce the drag friction reducing the amount of power necessary to pump the fluid downhole. Additionally, chemicals are often added to the fluid to aid in wettability, pH control and bacterial control. [0002] Generally the fracturing process includes pumping the fracturing fluid from the surface through a tubular. The tubular has been prepositioned in the wellbore to access the desired hydrocarbon formation. The tubular has been sealed both above and below the formation to isolate fluid flow either into or out of the desired formation and to prevent unwanted fluid loss. Pressure is then provided from the surface to the desired hydrocarbon formation in order to open a fissure or crack in the hydrocarbon formation. [0003] One type of chemical that may be used to improve the fracturing process is a chemical to allow the water to carry the proppant without having the proppant settle out of the mixture. One of the most common chemicals to be used for this purpose is a guar or polysaccharide used as linear gel system. In the past it was not unusual to utilize 30 or 40 pounds of gelling agent per thousand gallons of water. Unfortunately, due to the greatly increased demand for gelling agent and currently limited supply the cost per pound of gelling agent has greatly increased. [0004] A means of reducing the amount of gelling agent in a hydraulic fracturing fluid when freshwater is used as the main component of the hydraulic fracturing fluid is to reduce the total amount of gelling agent used. Typically a friction reducer was used to enhance the ability of the reduced amount of gelling agent to carry the proppant. In freshwater such a mixture could approach the performance of using gelling agent alone. [0005] Large amounts of fluid, typically water, are required in a typical hydraulic fracturing operation. At the well site, the fluid is mixed with the appropriate chemicals and proppant particulates and then pumped down the wellbore and into the cracks or fissures in the hydrocarbon formation. A typical slick water hydraulic fracturing fluid could include a partially hydrolyzed polyacrylamide polymer as a friction reducer. [0006] In many instances it may be preferable to use the produced water from the well as the main component of the fracturing fluid. Unfortunately, water produced from most hydrocarbon wells contain large quantities of dissolved solids, particularly the divalent cations such as sodium, calcium, and magnesium. When the concentration of the divalent cations exceed 50 parts per million the fluid is referred to as a brine solution. Produced brine solution reduces the effectiveness of current friction reducers to assist the gelling agent in transporting the proppant. In freshwater the friction reducer may increase the viscosity of the linear gel systems when using a reduced amount of gelling agent by as much as 90% where in a brine solution the same degree of substitution has a marginal effect on the viscosity of the linear gel system. [0007] In the search for a means to reduce the amount of gelling agent it was found that, in fresh water, 50 percent of the gelling agent could be replaced by small amounts of particular friction reducers. In this instance the effectiveness of the proppant transport mechanism (the gelling agent) and the friction reducer could be maintained at levels roughly equivalent to using the full amount of the gelling agent. [0008] Unfortunately when a brine solution is utilized as the main component of the fracturing fluid using the previous compositions alone to reduce the total amount of gelling agent is no longer possible. SUMMARY OF THE INVENTION [0009] When a brine solution has been determined to be preferable to freshwater as a basis for the fracturing fluid a new solution utilizing a mixture of brine, a reduced amount of gelling agent, a friction reducer, and a particular quaternary salt may be used. [0010] By utilizing the proper ratios of friction reducer to quaternary salt it is possible to reduce the total amount of gelling agent utilized without negatively affecting the ability of the fluid to transport proppant into the formation. [0011] Generally, when in the presence of brine the gelling agent may be reduced by half by generally adding certain amounts of a friction reducer a quaternary salt. In the embodiments described below the brine has a divalent cation concentration in excess of 50 parts per million, where the most frequently utilized, but not only brine has a divalent cation concentration between 50 and 10,000 parts per million. The gelling agent used may be from 5 to 25 pounds per thousand gallons of water. The friction reducer used may be from 1 to 30 pounds per thousand gallons of water The quaternary salt used may be from 0.1 to 4.2 pounds per thousand gallons of water. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a graph that depicts the viscosity of a 20 pound gelling agent mixture compared to a 10 pound gelling agent mixture with various additives with respect to time. [0013] FIG. 2 is a graph that depicts the viscosity of a 30 pound gelling agent mixture compared to a 15 pound gelling agent mixture with various additives with respect to time. [0014] FIG. 3 is a graph that depicts the viscosity of a 20 pound gelling agent mixture compared to a 10 pound gelling agent mixture and 12.5 pounds of friction reducer with various amounts of a quaternary salt with respect to time. DETAILED DESCRIPTION [0015] The description that follows includes exemplary apparatus, methods, techniques, or instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described embodiments may be practiced without these specific details. [0016] In the tests referred to below the brine is an American Petroleum Institute standard brine that is 8.5% weight to volume sodium chloride and 2.5% weight to volume of calcium chloride. [0017] Also in the tests below viscosity is tracked over time. The viscosity of the fluid is a typical measure of a fluids ability to transport proppant. [0018] Typically, polyacrylamide and polyacrylate polymers and copolymers are used as friction reducers at low concentrations for all temperatures ranges. [0019] Typical gelling agents include guar gums, hydroxypropyl guar, carboxymethyl hydroxypropyl guar, carboxymethyl guar, and carboxymethyl hydroxyethyl cellulose. Suitable hydratable polymers may also include synthetic polymers, such as polyvinyl alcohol, polyacrylamides, poly-2-amino-2-methyl propane sulfonic acid, and various other synthetic polymers and copolymers. Other examples of such polymers include, without limitation, guar gums, high-molecular weight polysaccharides composed of mannose and galactose sugars, or guar derivatives such as hydropropyl guar (HPG), carboxymethyl guar (CMG), carboxymethylhydropropyl guar (CMHPG), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), carboxymethylhydroxyethylcellulose (CMHEC), xanthan, and scleroglucan. [0020] The preferred quaternary salt is Alkyl (C12-16) Dimethylbenzylammonium chloride. Typical quaternary salts may be described by the formula R 1 R 2 R 3 ArN+X − , where R 1 and R 2 are carbyl groups including 1 to 3 carbon atoms, R 3 is a carbyl group including about 8 to about 20 carbon atoms, Ar is an aryl group and X − is a counterion, (2) compounds of the general formula R 1 R 2 R 3 R 4 N+X − , where R 1 and R 2 are carbyl group including 1 to 3 carbon atoms, R 3 and R 4 are a carbyl group including about 6 to about 10 carbon atoms, and X − is a counterion or (3) mixtures and combinations thereof, where X − includes chloride (Cl − ), bromide (Br − ), hydroxide (OH − ), or mixtures thereof. [0021] FIG. 1 is a graph that depicts the viscosity of various fracturing fluids with respect to time. Reference numeral 10 depicts a guar solution utilizing 20 pounds of gelling agent per 1000 gallons of brine. Reference numeral 12 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 10 pounds of gelling agent per 1000 gallons of brine with an additional 8.75 pounds of a friction reducer per 1000 gallons of brine. As can be readily observed the viscosity falls off dramatically with the removal of 50% of the gelling agent while the addition of the friction reducer seemingly did little or nothing to prevent the radical drop-off in viscosity. [0022] Reference numeral 14 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 10 pounds of gelling agent per 1000 gallons of brine with 8.75 pounds of friction reducer per 1000 gallons of brine, and an additional 0.42 pounds of a quaternary salt per thousand gallons of water. The graph indicates that the addition of a small amount of quaternary salt slightly improves the viscosity of the gelling agent/friction reduction mixture despite the presence of the sodium chloride and calcium chloride. [0023] Reference numeral 16 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 10 pounds of gelling agent per 1000 gallons of brine, with 8.75 pounds of friction reducer per 1000 gallons of brine, and a slightly higher amount of quaternary salt, now 2.09 pounds of a quaternary salt per thousand gallons of water is added. With the additional quaternary salt the viscosity is again improved with respect to both the mixtures graphed as reference numeral 12 and 14 . [0024] Reference numeral 18 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 10 pounds of gelling agent per 1000 gallons of brine, with 8.75 pounds of friction reducer per 1000 gallons of brine, and an even higher amount of quaternary salt, now 4.17 pounds of a quaternary salt per thousand gallons of water is added. With the additional quaternary salt the viscosity is again improved with respect to the mixtures graphed as reference numeral 12 , 14 , and 16 . [0025] Reference numeral 20 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 10 pounds of gelling agent per 1000 gallons of brine. However, the amount of friction reducer is increased slightly to 12.5 pounds per 1000 gallons of brine and the amount of quaternary salt is reduced to 2.09 pounds per thousand gallons of water. In this case the quaternary salt is reduced to the same amount as used before and graphed as reference numeral 16 but the friction reducer is increased slightly. With the proper ratios of friction reducer and quaternary salt the viscosity performance of the mixture approximates that of the 100% gelling agent. [0026] FIG. 2 is a graph that depicts the viscosity of various fracturing fluids with respect to time. In this case reference numeral 22 depicts a gelling agent solution utilizing 30 pounds of gelling agent per 1000 gallons of brine. However in this case each of the other mixtures utilize a reduction in the amount of gelling agent to 15 pounds per thousand gallons of water instead of a reduction to 10 pounds of gelling agent per thousand gallons of water as were graphed in FIG. 1 . Reference numeral 24 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 15 pounds of gelling agent per 1000 gallons of brine, with an additional 14.375 pounds of a friction reducer per 1000 gallons of brine. As can be readily observed, again the viscosity falls off dramatically with the removal of even 25% of the gelling agent while the addition of the friction reducer seemingly did little or nothing to prevent the radical drop-off in viscosity. [0027] Reference numeral 26 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 15 pounds of gelling agent per 1000 gallons of brine, with 14.375 pounds of friction reducer per 1000 gallons of brine, with 0.83 pounds of a quaternary salt per thousand gallons of water. With the additional quaternary salt the viscosity is only slightly improved with respect to the mixture graphed as reference numeral 24 . [0028] Reference numeral 28 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 15 pounds of gelling agent per 1000 gallons of brine, with 14.375 pounds of friction reducer per 1000 gallons of brine, with 2.09 pounds of quaternary salt per thousand gallons of water. In this case, with the stated ratios of friction reducer and quaternary salt the viscosity performance of the mixture closes in on the performance of the 100% gelling agent but does not quite match it. [0029] FIG. 3 is a graph that depicts the viscosity of various fracturing fluids with respect to time. In this case reference numeral 30 depicts a gelling agent solution utilizing 20 pounds of gelling agent per 1000 gallons of brine. [0030] Reference numeral 32 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 10 pounds of gelling agent per 1000 gallons of brine with an additional 12.5 pounds of a friction reducer per 1000 gallons of brine. As can be readily observed the viscosity falls off dramatically with the removal of 50% of the gelling agent while the addition of the friction reducer seemingly did little or nothing to prevent the radical drop-off in viscosity. [0031] Reference numeral 34 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 10 pounds of gelling agent per 1000 gallons of brine with 12.5 pounds of friction reducer per 1000 gallons of brine, and 0.42pounds of quaternary salt per thousand gallons of water. The graph indicates that the addition of a small amount of quaternary salt slightly improves the viscosity of the gelling agent/friction reduction mixture with respect to the mixture depicted by reference numeral 32 , despite the presence of the sodium chloride and calcium chloride. [0032] Reference numeral 36 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 10 pounds of gelling agent per 1000 gallons of brine, with 12.5 pounds of friction reducer per 1000 gallons of brine, and a slightly higher amount of quaternary salt, now 0.83 pounds of quaternary salt per thousand gallons of water. With the additional quaternary salt the viscosity is again improved with respect to both the mixtures graphed as reference numeral 32 and 34 . [0033] Reference numeral 38 depicts a gelling agent solution utilizing a reduced amount of gelling agent, 10 pounds of gelling agent per 1000 gallons of brine, with 12.5 pounds of friction reducer per 1000 gallons of brine, and an even higher amount of quaternary salt, now 2.09 pounds of quaternary salt per thousand gallons of water. In this case, as in the case depicted by reference numeral 20 in FIG. 1 , the proper ratios of friction reducer and quaternary salt have a viscosity performance that approximates that of the 100% gelling agent. [0034] 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. [0035] 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 method to reduce the amount of gelling agent utilized in hydraulic fracturing fluids in the presence of a relatively high concentration of brine.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims benefit to the U.S. provisional applications Serial No. 60/438,016, filed on Jan. 3, 2003, and Serial No. 60/486,275, filed on Jul. 10, 2003. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not applicable. BACKGROUND OF THE INVENTION [0003] Many plants and plant parts are of great economic importance to people. Fruit, vegetable, edible tuber and cut flower businesses are all multibillion dollar industries globally. Turf grass is another multibillion dollar industry. Over the years, people have learned to increase the production of various economically important plants and plant parts. Chemical agents have been applied to plants to increase the marketable yield of fruits, for example, by inhibiting fruit drop from the trees. In addition, people have learned to reduce the loss of economically important plant parts during the post-harvest storage and marketing period. In this regard, various chemical agents have been used to prolong the storage and shelf life of fruits, vegetables and cut flowers. However, many of the yield-increasing agents have the undesirable effect of causing the fruits and vegetables to soften and thus lead to poor storage and shelf life. Furthermore, many of the yield-increasing and the storage and shelf life-prolonging agents have toxicological and environmental concerns. There is a tremendous interest in the plant industry to find alternative agents. [0004] Another major challenge to the plant industry relates to the protection of economically important plants from abiotic and biotic stress-related injuries. Specifically, over 60% of the crop loss in the U.S. from the late 1940s to the late 1990s was due to abiotic stresses (see USDA Agricultural Statistics, 1998). Abiotic stresses include chilling, freezing, drought, heat and other environmental factors. Biotic stresses, which include those caused by insects, nematodes, snails, mites, weeds, pathogens (e.g., fungus, bacteria and viruses), and physical damage caused by human and non-human animals, have also led to significant crop loss in the U.S. Thus, there is a tremendous interest in the plant industry to find a technology that can be used to prevent or mitigate stress injury and to accelerate recovery following a stress injury. [0005] In the recent years, certain phospholipids such as lysophosphatidylethanolamine (LPE) have been found to be able to deliver some beneficial effects to various economically important plants and plant parts, which include protecting the plants from stress-related injuries (see WO 01/721330; and US 2003/0064893) and prolonging the storage and shelf life as well as accelerating the maturation of the plant parts (see Farag, K. M. et al., Physiol. Plant, 87:515-524 (1993); Farag, K. M. et al., HortTech., 3:62-65 (1993); Kaur, N., et al., HortScience, 32:888-890 (1997); Ryu, S. B., et al., Proc. Natl. Acad. Sci. U.S.A., 94:12717-12721 (1997); U.S. Pat. Nos. 5,126,155 and 5,110,341; and WO 99/23889). However, for large scale applications, these lysophospholipids are currently relatively expensive. Alternative agents that have the potential to provide cost effective delivery of the same or greater effects produced by the lysophospholipids are desired in the art. SUMMARY OF THE INVENTION [0006] The present invention provides methods for delivering various beneficial effects to a plant or plant part by treating the plant or plant part with an effective amount of modified lecithin to change the health, growth or life cycle of the plant or plant part. [0007] In one aspect, the present invention relates to a method for improving the quality of a plant part (e.g., the quality of fruits, vegetables, flowers or tubers) by treating the plant part or its corresponding plant with an effective amount of modified lecithin. As an example, the method can be used to improve the turgidity, color and flavor of fruits and vegetables and to reduce fruit cracking. Modified lecithin that can be employed in the methods of the present invention include enzyme-modified lecithin (EML) and chemically modified lecithin such as acetylated lecithin (ACL) and hydroxylated lecithin (HDL). [0008] In another aspect, the present invention relates to a method of retarding senescence in a plant part by treating the plant part or its corresponding plant with an effective amount of modified lecithin. The retardation of senescence can lead to prolonged storage and shelf life for a variety of products such as fruits, vegetables, flowers and tubers. [0009] In another aspect, the present invention relates to a method for increasing the size, weight or both of a plant part (e.g., fruits) by treating the plant part or its corresponding plant with an effective amount of modified lecithin. [0010] In another aspect, the present invention relates to a method for stimulating the growth of a plant or plant part by treating the plant or plant part with an effective amount of modified lecithin. This method can be used to enhance root formation and development of roots on cuttings, to enhance tuber formation, and to stimulate turf grass growth. [0011] In another aspect, the present invention relates to a method of improving the aesthetic attributes of a plant or plant part by treating the plant or plant part with an effective amount of modified lecithin. A plant or plant part with improved aesthetic attributes will look more appealing to an ordinary consumer. [0012] In another aspect, the present invention relates to a method for increasing fruit set on a plant or reducing fruit drop by treating the plant or a suitable part thereof with an effective amount of modified lecithin. [0013] In another aspect, the present invention relates to a method of protecting a plant or plant part from a stress-related injury by treating the plant or plant part with an effective amount of modified lecithin. [0014] In other aspects, the present invention relates to methods of eliciting the hypersensitive response in a plant or plant part, which can be detected by measuring the increase in the total activity of one or more enzymes such as phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD) and indole-3-acetic acid oxidase (IAA oxidase) in a plant or plant part, and increasing lignin synthesis in a plant or plant part by treating the plant or plant part with an effective amount of modified lecithin. [0015] In another aspect, the present invention relates to a method for protecting a plant or plant part from a stress-related injury caused by an abiotic or biotic stress. The method involves adding an effective amount of modified lecithin into the agrochemical intended to be applied to the plant or plant part. BRIEF DESCRIPTION OF THE DRAWINGS [0016] [0016]FIG. 1 shows changes in protein content and PAL activity in radish cotyledons exposed to 1-amminocyclopropane-1-carboxylic acid (ACC, a precursor to ethylene), kinetin, and EML all at 20 mg/L. [0017] [0017]FIG. 2 shows short-term kinetics of PAL activity in EML-treated radish cotyledons. [0018] [0018]FIG. 3 shows effect of EML on lignin content of kinetin-induced expanding cotyledons of radish. [0019] [0019]FIG. 4 shows changes in POD activity in cotyledons of radish exposed to ACC, kinetin, or EML. [0020] [0020]FIG. 5 shows PAL activity in leaves of mung bean seedlings treated with or without EML (both 20 mg/L) via the transpiration stream. [0021] [0021]FIG. 6 shows the effect of LPE and EML on PPO activity in radish cotyledons. [0022] [0022]FIG. 7 shows the effect of LPE and EML on IAA oxidase activity in radish cotyledons. [0023] [0023]FIG. 8 shows the effect of lecithins on the activity of IAA oxidase in expanding radish cotyledons. [0024] [0024]FIG. 9 shows the impact of soy EML on grape firmness. [0025] [0025]FIG. 10 shows the impact of soy EML on apple firmness. [0026] [0026]FIG. 11 is a product-limit survival fit survival plot, which illustrates the ability of 1000 ppm soy EML aqueous solution to improve vine-ripe tomato fruit storage when applied pre-harvest. [0027] [0027]FIGS. 12-14 illustrate the sizing impact of soy EML applied approximately 2 weeks prior to harvest in Fowler, Calif. on Summer Sweet peaches. [0028] [0028]FIGS. 15 and 16 illustrate the color impact of soy EML applied approximately 2 weeks prior to harvest in Fowler, Calif. on Summer Sweet peaches. [0029] [0029]FIGS. 17-19 illustrate the sizing impact of soy EML, applied approximately 10% color break in Mendota, Calif. on red bell peppers. [0030] [0030]FIGS. 20 and 21 illustrate the sizing impact of soy EML applied approximately 3 weeks prior to harvest on McIntosh apples in Gays Mills, Wis. [0031] [0031]FIGS. 22-24 illustrate the root formation impact of 20 ppm soy EML solution on mung bean rooting. FIGS. 22 and 23 are pictures of control and EML-treated roots at the end of the experiment. FIG. 24 shows the average number of roots in the control and EML-treated group at the end of the experiment. [0032] [0032]FIG. 25 illustrates the impact of soy EML on fruit drop of McIntosh apples conducted in Gays Mills, Wis. DETAILED DESCRIPTION OF THE INVENTION [0033] It is disclosed here that modified lecithin, including the relative low cost EML, ACL and HDL, can deliver a variety of beneficial effects when applied to a plant or plant part by changing the health, growth or life cycle of the plant or plant part. The term “life cycle” is used broadly here to encompass both the pre-harvest and post-harvest stages of the plant or plant part. In general, modified lecithin can improve the quality and overall health, stimulate the growth and retard the senescence process in a plant or plant part. The modified lecithin can also increase fruit set, reduce fruit drop and protect a plant or plant part from stress-related injuries. Based on these properties, modified lecithin can be applied in many different ways to benefit the plant industry. For example, modified lecithin can be applied to improve the quality of fruits, vegetables, tubers and cut flowers in terms of their turgidity, color, flavor and scent, and to reduce fruit cracking. Modified lecithin can also be applied to prolong the storage and shelf life of various plant parts such as fruits, vegetables, tubers and cut flowers through retarding or delaying the senescence process in these plant parts. By taking advantage of the growth stimulation activity of modified lecithin, one can increase the size and/or weight of fruits, vegetables and tubers, stimulate turf grass growth, and increase the number of tubers, roots and shoots. One can also make a plant or plant part more appealing to consumers by using modified lecithin to improve the overall health of the plant or plant part. Furthermore, modified lecithin can be applied to increase fruit production by increasing fruit set and reducing fruit drop. In addition, modified lecithin can be used to reduce crop loss caused by stress-related injuries. The beneficial effects disclosed here are applicable to all plants and plant parts that have commercial value (e.g., fruits, flowers, leaves, roots and stems). Preferably, the present invention is practiced on fruits, vegetables, tubers, cut flowers, and their corresponding plants. The present invention is also preferably practiced on turf grass, bedding plants and other functional and decorative plants. [0034] At the physiological level, inventors discovered that EML can trigger a cascade of hypersensitive reactions in a plant that are characterized by the induction of a variety of enzymes, such as lignin synthesizing enzymes including PAL, POD and PPO, leading to the synthesis and deposition of additional lignin to the plant cell walls (see examples below). This response is similar to the self-defense hypersensitive response seen in plants that have been infected by pathogens (e.g., fungi, bacteria or viruses), which secrete one or more elicitors that induce the response. Through the induction of PAL, POD, PPO and other enzymes, the elicitor-induced hypersensitive response is known to impact the direction of carbon flux (e.g., to increase phenylpropanoid, isoprenoid and phytoalexin production) which in turn causes various physiological response such as growth of vegetative and reproductive organs, color development and stress mitigation (Hammond-Kosack K., and Jones J 2000 Responses to Plant Pathogens, In: Biochemistry & Molecular Biology of Plants, Buchanan B B, Gruissem W, and Jones R L eds. American Society of Plant Biologists, Rockville, Md.). One of the end results that relates to stress mitigation is the collapse of the infected plant tissue, which traps and thus prevents the pathogens from infecting other parts of the plant. Without intending to be limited by theory, the inventors believe that the hypersensitive response triggered by EML, which occurs in the absence of a physical wound, is not as dramatic as that triggered by an elicitor from a pathogen and thus does not lead to tissue collapse nor does it impede normal tissue function. However, the limited additional amount of lignin deposited to the cell walls is sufficient to reinforce the cell walls and provide additional structural integrity to plant tissues. As a result, the plant or plant part can better retain water, nutrients and other essential components, leading to better overall quality and health. For harvested plant parts such as fruits, vegetables, tubers and cut flowers, this will also lead to the retardation or delay of the senescence process and thus prolong their storage and shelf life. For living plants and plant parts, this can translate into better growing capabilities, which for example can lead to bigger and heavier products. Furthermore, the improved structural integrity and ability to retain important components can lead to increased fruit set and a reduction in fruit drop. In addition, the plant or plant part can better withstand various stress situations. [0035] As used herein, the term “modified lecithin” means a lecithin modified to enrich its constituency of plant growth modifying compounds, specifically including EML, ACL, HDL and other similar modified lecithins that have plant growth beneficial effects disclosed here for the specific modified lecithins EML, ACL, and HDL. Using the effects noted for EML, ACL and HDL as examples below, one of ordinary skill in the art can test other modified lecithins for the beneficial effects disclosed here and demonstrated in the examples below using the techniques described here. To the extent that the exact efficacy of a particular modified lecithin is not demonstrated in the examples below, it can be easily determined by a skilled artisan through routine experimentation with the systems described in the examples or other systems that a skilled artisan is familiar with. For example, a skilled artisan can use the radish cotyledon system described in Example 1 to measure either lignin deposition or at least one of the PAL, POD, PPO and IAA oxidase enzymatic activities. If a modified lecithin increases lignin deposition or the enzymatic activities measured, the modified lecithin is within the scope of the present invention. [0036] Commercially, lecithin refers to a complex product derived from animal or plant tissues that is commonly used as a wetting and emulsifying agent in a variety of commercial products and is not normally expected to have biological effects in plants. Lecithin contains acetone-insoluble phospholipids (including phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylserine (PS) and other phospholipids), sugars, glycolipids, and some other substances such as triglycerides, fatty acids, and cholesterol. Refined grades of lecithin may contain any of these components in varying proportions and combinations depending on the type of fractionation used. In its oil-free form, the preponderance of triglycerides and fatty acids is removed and the product contains 90% or more phosphatides representing all or certain fractions of the total phosphatide complex. The consistency of both natural grades and refined grades of lecithin may vary from plastic to fluid, depending upon free fatty acid and oil content, and upon the presence of absence of other diluents. Its color varies from light yellow to brown, depending on the source and on whether it is bleached or not (usually by hydrogen peroxide and benzoyl peroxide). Lecithin is only partially soluble in water, but it readily hydrates to form emulsions. The oil-free phosphatides are soluble in fatty acids, but are practically insoluble in fixed oils. When all phosphatide fractions are present, lecithin is partially soluble in alcohol and practically insoluble in acetone. In a preferred embodiment of the present invention, a food-grade lecithin is used as the starting material to make modified lecithin. This will minimize the safety and environmental concerns over applying modified lecithin to food products. However, a non-food-grade lecithin can also be employed. By current definition, a food-grade lecithin (CAS: 8002-43-5) has the following properties: (1) acetone-insoluble matter (phosphatides) is not less than 50%; (2) acid value is not more than 36; (3) heavy metals (as Pb) is not more than 0.002%; (4) hexane-insoluble matter is not more than 0.3%; (5) lead is not more than 10 mg/kg; (6) peroxide value is not more than 100; and (7) water is not more than 1.5%. [0037] EML refers to a lecithin that has been enzymatically modified (e.g., by phospholipase A 2 or pancreatine), a modification done to enhance the surfactant or emulsifying characteristics of the lecithin. Chemical procedures can also be used to make similar modifications as those made by phospholipase A 2 . In a preferred embodiment, a food-grade EML is used in the present invention to minimize the safety and environmental concerns. However, non-food-grade EML can also be employed. By current definition, a food-grade EML has the following properties: (1) acetone-insoluble matter (phosphatides) is not less than 50%; (2) acid value is not more than 40%; (3) lead is not more than 1 ppm as determined by atomic absorption spectroscopy; (4) heavy metals (as Pb) is not more than 20 ppm; (5) hexane-insoluble matter is not more than 0.3%; (6) peroxide value is not more than 20; (7) water is not more than 4%; and (8) lysolecithin is 50 to 80 mole percent of phosphatides as determined by “Determination of Lysolecithin Content of Enzyme-Modified Lecithin: Method 1 (1985),” which is incorporated by reference in its entirety. [0038] Examples of chemically modified lecithin include ACL and HDL. These chemical modifications were also intended to enhance the surfactant or emulsifying characteristics of the lecithin. ACL can be prepared by treating lecithin with acetic anhydride. Acetylation mainly modifies phospholipids into N-acetyl phospholipids. HDL can be prepared by treating lecithin with hydrogen peroxide, benzoyl peroxide, lactic acid and sodium hydroxide, or with hydrogen peroxide, acetic acid and sodium hydroxide, to produce a hydroxylated product having an iodine value preferably 10% lower than that of the starting material. Also preferably, the separated fatty acid fraction of the resultant product has an acetyl value of about 30 to about 38. [0039] EML, ACL and HDL are commonly used as wetting or emulsifying agents and are not normally expected to be biologically active in plants. The inventors demonstrated for the first time that they can deliver a variety of biological effects as described in the examples below. It is noted that the unmodified lecithin does not cause the same effects. It is known in the art that pure lysophospholipids, such as LPE, can cause some of the EML-induced effects disclosed herein. However, the same effects that EML has cannot be explained by the lysophospholipids contained therein. In comparison to pure lysophospholipids, EML is a much more complicated product that contains many other types of molecules, which render EML as a whole, a different product from pure lysophospholipids in terms of its constituents and chemical and physical characters. In the radish cotyledon bioassay described in the examples below, 20 mg/L EML was more effective than 20 mg/L LPE for the induction of hypersensitive response in terms of the activation of enzymes PPO and IAA oxidase, even though the total amount of lysophospholipids in 20 mg/L EML is much less than that in the 20 mg/L LPE. These data indicate that one or more non-lysophospholipid components or chemical/physical properties of EML are important for the effects observed. Furthermore, the fact that ACL and HDL, which are not enriched in lysophospholipids, were also able to induce the activity of IAA oxidase, is consistent with the notion that modified lecithin works differently from pure lysophospholipids. [0040] Lecithin can be obtained from a variety of animal and plant sources including egg yolks, soybeans, sunflowers, peanuts, sesame and canola. The source and process for producing lecithin and methods for enzymatically (e.g., by phospholipase A 2 ) or chemically modifying lecithin are known to the art. In addition, lecithin, EML, ACL and HDL are commercially available from a variety of sources such as Solae, LLC (Fort Wayne, IN). Examples of EML and chemically modified lecithin that can be used in the present invention can be found in Food Chemicals Codex, 4 th ed. 1996, pages 198-221; and 21 C.F.R. sec. 184.1063, sec. 184.1400 and sec. 172.814, both of which are herein incorporated by reference in their entirety. [0041] In one aspect, the present invention relates to a method of improving the quality of harvested plant parts such as fruits, vegetables, flowers and tubers by treating the plant parts with an effective amount of modified lecithin. In a related aspect, the present invention relates to a method for retarding senescence and enhancing the storage and shelf life of the harvested plant parts by treating the plant parts with an effective amount of modified lecithin. For these applications, modified lecithin can be applied to the plant part either before or after they are harvested. As discussed above, modified lecithin's effects on the quality, senescence and storage and shelf life of a plant part is believed to relate to its ability to reinforce the cell walls and provide additional structural integrity to plant tissues. A harvested plant part is usually limited to the water, nutrients and other essential molecules including its structural components that were there at the time of harvest. Over time, with the loss of these molecules and components, the plant part will undergo the senescence process, leading to the rotting and degradation of the plant part. By reinforcing the cell walls and providing more structural integrity, modified lecithin allows the plant part to better preserve the above molecules and components and thus improve the quality of the plant part. Further, the degradation and senescence process can be retarded as a result and the storage and shelf life of the plant part can be prolonged. For cut flowers wherein the stems are often immersed in water or a nutrient solution of some kind, the quality can still be improved and the shelf life be prolonged by including modified lecithin in the treatment solution. [0042] As used herein, the meaning of “quality of a plant part” depends on the plant part in question and refers to at least one of the following: the firmness (turgidity), color, flavor, scent and cracking of the plant part. The quality of the plant part is considered to be improved if the plant part is firmer (more turgid) and/or has a more desirable color, flavor or scent to an average consumer. For fruits, cracking reduction is also considered an improvement in quality. [0043] In another aspect, the present invention relates to a method for increasing the size, weight or both of a plant part by treating the living plant or the plant part thereof with an effective amount of modified lecithin. The size of a plant part refers to its volume. A skilled artisan knows how to measure and compare the size of a particular plant part. For example, for a substantially round fruit, diameter can be used as a measure of fruit size. For leaves that have similar thickness, the surface area can be used as an indication of leave size. The present invention is particularly useful for increasing the size, weight or both of various fruits, foliage, flowers and tubers. As shown in the examples below, as a result of the size increase, the number of marketable apples from an apple tree was increased. [0044] In a related aspect, the present invention relates to a method of enhancing root formation and development of roots on cuttings by treating the cuttings with an effective amount of modified lecithin. By enhancing root formation or development of roots on cuttings, we mean that modified lecithin can increase the number of roots, the overall length of the roots, or both. When a root is a commercial product itself, the method can be used to increase root production. Otherwise, the method of the present invention can be used to stimulate the growth and development of a plant. In particular, modified lecithin can be added to potting soil media to promote root formation and development. [0045] In another related aspect, the present invention relates to a method for enhancing tuber formation by treating a tuber plant or the tuber thereof with an effective amount of modified lecithin. By enhancing tuber formation, we mean that modified lecithin can increase the number of tubers. [0046] In another related aspect, the present invention relates to a method of stimulating turf grass growth by treating the turf grass with an effective amount of modified lecithin. Turf grass growth can be measured by any method familiar to a skilled artisan. For example, dry weight or biomass of the turf grass can be measured. [0047] In another aspect, the present invention relates to a method of improving the aesthetic attributes of a plant or plant part by treating the plant or plant part with an effective amount of modified lecithin to improve the overall health of the plant or plant part. Without intending to be limited by theory, the inventors believe that modified lecithin achieves this effect by reinforcing the plant cell walls and providing more structural integrity to plant tissues. This activity of modified lecithin is particularly useful in making the turf grass, bedding plants and other functional and decorative plants more appealing to consumers. [0048] In another aspect, the present invention relates to a method of increasing fruit set on or reducing fruit drop from a plant by treating the plant or a suitable part thereof with an effective amount of modified lecithin. Preferably, the whole plant is sprayed with a solution that contains modified lecithin. By increasing fruit set, the number of fruits available for harvest can be increased. By reducing fruit drop, one can reduce fruit loss and potentially increase fruit size as well. The method is particularly useful for fruits such as apples wherein a relatively large number of fruits tend to drop prior to harvest. [0049] In another aspect, the present invention relates to a method for protecting a plant, or plant part from a stress related injury. The method involves applying to the plant or plant part an effective amount of modified lecithin. By protecting a plant or plant part from a stress related injury, we mean one or more of the following: (1) complete prevention of the injury; (2) reduction in severity of the injury; (3) recovery from the injury to a higher degree; and (4) speedier recovery from the injury. [0050] As used herein, the term “stress-related injury” refers to an injury resulting from an abiotic and/or a biotic stress. “Abiotic stress” refers to those non-living substances or environmental factors which can cause one or more injuries to a plant or plant part. Examples of abiotic stress include but are not limited to chilling, freezing, wind, hail, flooding, drought, heat, soil compaction, soil crusting and agricultural chemicals such as pesticides, insecticides, fungicides, herbicides and fertilizers. “Biotic stress” refers to those living substances which cause one or more injuries to a plant or plant part. Examples of biotic stress include but are not limited to pathogens (e.g., fungi, bacteria and viruses), insects, nematodes, snails, mites, weeds, and physical damage caused by human and non-human animals (e.g., grazing, and treading). To protect a plant or plant part from stress-related injuries, modified lecithin can be applied at one or more of the following stages: (1) prior to exposure to stress; (2) during exposure to stress; and (3) after exposure to stress. Furthermore, modified lecithin can be used as an adjuvant for plant growth regulators, pesticides, insecticides, fungicides, herbicides, fertilizers and other agrochemicals that people normally use on plants wherein the use can deliver stress to plants. [0051] In practicing the present invention, a skilled artisan can readily determine whether to apply modified lecithin to only one particular plant part or the whole plant. Using stress-related injury protection as an example, if a stress condition only affects one particular plant part and the goal is to protect that particular part, it may be sufficient to treat that particular plant part with modified lecithin. [0052] Any suitable method of treating a plant or plant part with modified lecithin can be used in the present invention and a skilled artisan is familiar with these methods. Preferably, a plant or plant part is treated with a solution that contains modified lecithin. The preferred solvent for modified lecithin for the purpose of the present invention is water. However, other suitable solvents such as organic solvents can also be used. To treat a plant or plant part with a solution that contains modified lecithin, the plant or plant part can be sprayed with the solution, or it can be dipped or soaked in the solution. Other suitable methods of exposing a plant or plant part to modified lecithin can also be used. For cut-flowers in particular, they can be treated by dipping the cut end of the stem in a modified lecithin-containing solution. For treating underground roots or tubers, modified lecithin can be included in the soil. [0053] The dosage of modified lecithin to be applied for a particular application and the duration of treatment will depend on the type of plant or plant part being treated, the method modified lecithin is being applied, the purpose of the treatment and other factors. A skilled artisan can readily determine the appropriate treatment conditions. Generally speaking, when modified lecithin such as EML is delivered to a target plant or plant part in a solution, its concentration can range from about 1 ppm to about 20,000 ppm, from about 10 ppm to about 10,000 ppm or from about 25 ppm to about 5,000 ppm. The term “about” is used in the specification and claims to cover concentrations that slightly deviate from the recited concentration but retain essential function of the recited concentration. [0054] In addition to modified lecithin, one or more additives that enhance wettability, uptake and effectiveness of modified lecithin can be used together with modified lecithin in practicing the present invention. Examples of additives that can be used in the method of the present invention include but are not limited to ethanol and agricultural adjuvants such as Tactic™ (Loveland Industries, Inc., Greeley, Colo.). The additives can be present in amount of from about 0.005% to about 5% (v/v), from about 0.025% to about 1% (v/v), or from about 0.03% to about 0.5% (v/v) in a treatment composition or formula. [0055] By way of example, but not limitation, examples of the present invention are described below. EXAMPLE 1 Effects of EML on Cotyledon Expansion and Hypersensitive Response Enzymes [0056] Materials and Methods [0057] The soy EML (Precept™ 8160™), ACL (Precept™ 8140™) and HDL (Precept™ 8120™) used in this example were purchased from Solae, LLC (Fort Wayne, Ind.). The egg EML was purchased from Primera Foods, Cameron, Wis. [0058] Seeds of Raphanus sativus L. cv. Cherry-Belle were germinated in darkness at 24° C. for 40 h in Petri dishes containing filter paper wetted with distilled water. The smaller of the two cotyledons was excised, the fresh weight determined, and 10 cotyledons placed adaxial side down on filter paper in Petri dishes containing 7.5 mL of phosphate buffered saline (PBS, 2 mM, pH 6.0) and the compounds to be tested at 20 mg/L. Cotyledons were then incubated under continuous illumination up to 72 h at 24° C. or 25° C. and the increase in fresh weight determined. Chlorophyll content was determined after extraction of tissue into 80% EtOH (containing butylated hydroxytoluene 10 mg/L) and quantified using the equations Chl a=(13.95A663)-(6.88A647) and Chl b=(24.96A652)-(7.32A663) as described by Lichtenthaler, HK ( Methods in Enzymology 148:350-382, 1987). IAA oxidase, PAL, PPO and POD activity were determined as described by Kato, M et al. ( Plant and Cell Physiology 41:440-447, 2000) and Li, X et al. ( Plant Science 164:549-556, 2003). [0059] Results [0060] In order to remove variability from the bioassay—due presumably to temporal changes in the concentration of root-derived cytokinins in cotyledons—the bioassay procedure was modified to routinely include 0.2 mg/L (approximately 1 μM) kinetin in the background. [0061] Cotyledon expansion growth: The effect of soy EML in the presence of kinetin on expansion growth was investigated and the results are shown in Table 1. In the presence of kinetin, soy EML resulted in an increase of cotyledon expansion growth relative to the control. TABLE 1 Effect of soy EML on kinetin-induced cotyledon expansion in radish. Ten cotyledons were incubated on filter discs wetted with 2 mM PBS (pH 6.0) containing either kinetin (20 mg/L) with or without EML (all 20 mg/L). Cotyledons were incubated under continuous illumination in incubation chamber at 25° C. for 72 h and the change in fresh weight and chlorophyll content determined. Change in Chlorophyll Chlorophyll fresh weight a + b a + b Chlorophyll Treatment (mg) % of control (μg/cotyledon) (mg/g FW) a/b Control 10.11 ± 1.33 100 31.57 ± 0.31 2.12 0.75 ACC  2.56 ± 0.39  25 35.90 ± 6.13 5.40 0.83 Kinetin 15.49 ± 1.81 153 54.10 ± 7.03 2.17 0.87 Kinetin/EML 18.59 ± 1.13 184 58.44 ± 5.76 2.47 0.93 [0062] In a similar experiment with cucumber cotyledons, the effect of EML on cotyledon expansion growth was tested with both soy and egg EML. As shown in Table 2, both soy and egg EML increased the cotyledon expansion growth. TABLE 2 Effect of soy and egg EML on expansion growth of cucumber cotyledons. Cotyledons were incubated on filter discs wetted with 2 mM PBS buffer (pH 6.0) containing kinetin (0.2 mg/l) with or without the lecithins (20 mg/L). Cotyledons were incubated under continuous illumination in an incubation chamber at 25° C. for 72 h and the change in fresh weight determined (n = 3). Treatment Change in fresh weight (%) % of control Control 199.6 ± 1.0  100 Soy EML 232.0 ± 16.6  116 Egg EML 245.4 ± 3.1  123 [0063] In a separate experiment, the effect of EML, ACL and HDL on cotyledon expansion growth were tested. All these modified lecithins increased the cotyledon expansion growth (Table 3). TABLE 3 Effect of soy EML, ACL, and HDL on expansion growth of radish cotyledons. Cotyledons were incubated on filter discs wetted with 2 mM PBS buffer (pH 6.0) containing kinetin (0.2 mg/L) with or without the lecithins (20 mg/L). Cotyledons were incubated under continuous illumination in an incubation chamber at 25° C. for 72 h and the change in fresh weight and chlorophyll content determined (n = 3). Treatment Change in fresh weight (mg) % of control Control 12.60 ± 2.04 100 HDL 14.39 ± 2.09 114 ACL 15.11 ± 2.15 120 Soy EML 14.55 ± 2.69 115 [0064] PAL (EC 4.3.1.5) activity: Ethylene is produced by plants in response to a variety of stresses, including wounding (Kato, M et al. Plant and Cell Physiology 41:440-447, 2000). Assuming the stress is of sufficient intensity and duration plants will also begin to show signs of senescence. This notwithstanding, stress is a common daily feature of plant growth and development and because plants are generally immobile they require mechanisms to cope with “normal” day-to-day stress. This is achieved by a system of built-in defense mechanisms. One of these systems involves PAL (EC 4.3.5.1) and activity of this enzyme increases when plants are wounded or exposed to pathogens and/or elicitors. Activity of PAL is also light regulated so transfer of dark-grown seedlings to light would be expected to increase enzyme activity. To determine whether EML acts as an elicitor in a hypersensitive-type response, the activity of PAL in radish cotyledons after exposure to soy EML was investigated and the results are shown in FIG. 1. [0065] EML caused a rapid but transient increase in protein content similar to that observed in kinetin-treated cotyledons. In this treatment, protein content started to decline after 6 h. In ACC-treated cotyledons protein accumulation was delayed and reached a maximum only 24 h after exposure to light. In all cases, accumulation of protein was associated with increased PAL activity. [0066] In EML-treated cotyledons, the increase in PAL was ballistic whereas it was progressively delayed in ACC, control, and kinetin-treated cotyledons. This observation provides strong evidence for a role for EML as an elicitor capable of stimulating PAL. [0067] Short-term kinetics of PAL induction by soy EML confirms that PAL activity was increased in EML-treated cotyledons (FIG. 2). Thus, EML activates PAL and likely increases the pheylpropanoid content of growing radish cotyledons. Increased lignin deposition can therefore be expected and lead to the retardation of expansion growth without influencing chlorophyll accumulation. To test this possibility, cotyledons were supplied kinetin (to promote expansion) together with EML and lignin content was determined. Lignin was quantified by measuring the amount of lignothioglycolic acid (LTGA) in extractive-free tissue samples prepared from the cotyledons treated with or without EML as described by Chen, M and McClure, J W ( Phytochemistry 53:365-370, 2000). The results in FIG. 3 show that by 72 h EML-treated cotyledons contained substantially more LTGA. [0068] These results, together with induction of PAL (FIGS. 1 & 2) and POD (FIG. 4) activity support the idea that EML acts as an elicitor and causes affected tissues to increase the biosynthesis of phenolic esters and lignin. [0069] POD (EC 1.11.1.7) activity: POD (EC 1.11.1.7) has been implicated in lignin formation at the step of polymerization of monolignols (Grisebach, H, Lignins, In: The Biochemistry of Plants Vol 7, Secondary Plant Products, Conn EE (ed.) Academic Press, New York, pp 457-478, 1981) and induction of POD activity following wounding has been demonstrated for a number of species (Kato, M et al., Plant and Cell Physiology 41:440-447, 2000; and references therein). To determine the effect of EML on induction of POD, activity of this enzyme was monitored during the 72 h incubation period after exposure to soy EML (20 mg/l) and the results are shown in FIG. 4. EML increased POD activity by approximately 15% (relative to control) within the first 6 h of incubation. Thereafter, POD activity declined in all treatments. The increase in POD activity at 48 and 72 h is a normal event in expansion growth and signifies the onset of organ maturity and the commencement of senescence. At this developmental stage, POD activity was lowest in kinetin-treated cotyledons followed by those treated with EML. Highest POD activity was measured in control and ACC-treated cotyledons. This suggests that EML can slow the progression of cotyledon leaf development into the senescence phase. [0070] Although the above result points to induction of components of the hypersensitive response pathway by EML they give no indication of a systemic-type mechanism. To determine whether in fact the response is systemic, mung bean seedlings were supplied solutions of EML via the transpiration stream, incubated for periods up to 72 h, and PAL activity of the cotyledon leaves determined. The results in FIG. 5 show that treatment of mung bean seedlings with EML via the transpiration stream did not change PAL activity in leaves. Thus, we can conclude that EML does not induce a typical systemic-type response. [0071] PPO (EC 1.14.18.1): Like PAL and POD, PPO is an important enzyme catalyzing lignin biosynthesis in plants. In the radish system, PAL and POD are induced by exposure to soy EML and as shown in FIG. 6, PPO was also induced and activity was at a maximum 48 h after treatment. By contrast, LPE did not induce PPO activity as EML did and ACC appeared to suppress PPO activity. In untreated and kinetin-treated cotyledons, enzyme activity appeared to increase gradually over time. [0072] IAA Oxidase activity: IAA homeostasis is an important process contributing to correlative control of plant growth and development. Generally, IAA is synthesized in the apices and in shoots; apically derived IAA is basipetally transported. It is the basipetal movement of IAA that modulates process such as apical dominance, adventitious rooting, tropistic responses etc. In the presence of soy EML, activity of IAA oxidase is increased whereas LPE has no apparent effect on this activity (FIG. 7). [0073] POD activity and IAA oxidase are involved in lignin biosynthesis and auxin catabolism respectively. A number of growth retardants have been shown to reduce elongation growth by impacting POD and IAA oxidase activities. In addition, increased IAA oxidase activity has been observed in tissues exposed to pathogens. Thus, the data in FIG. 7 indicates that EML acts as an elicitor and probably contributes to increased phenolic acid production and/or lignification and modulates endogenous IAA by impacting IAA oxidase. To determine whether this effect was due to enzyme modification of the parent lecithin, unmodified (soy lecithin) and modified (EML, ACL and HDL) lecithins were compared. [0074] The data in FIG. 8 illustrate that EML, ACL and HDL were very effective inducers of IAA oxidase activity. The unmodified lecithin appeared to have little or no effect on IAA oxidase activity. EXAMPLE 2 Impact of EML on Grape and Apple Firmness (Turgidity) [0075] The EML used in this example was soy EML (Precept™ 8160™) obtained from Solae, LLC (Fort Wayne, Ind.). [0076] [0076]FIG. 9 illustrates the ability of 2000 ppm soy EML aqueous solution to improve grape fruit firmness when applied pre-harvest. Applications of 2000 ppm soy EML were made in April 2003 using a hand operated mist bottle spraying to fully cover the grape clusters with tiny droplets that adhered securely to the fruits without running off. Harvesting took place approximately 2 weeks post application. 25 berries from each cluster were removed from pre-determined sectors of the rachis (with stem cap attached) and measured for firmness using a Firmtech firmness and diameter analyzer (BioWorks, Stillwater, Oklahoma). As shown in FIG. 9, EML treatment increased the firmness of the grapes. [0077] [0077]FIG. 10 illustrates the ability of 2000 ppm soy EML aqueous solution to improve apple fruit firmness when applied pre-harvest. Applications of 2000 ppm soy EML were made on Sep. 18, 2003 with a commercial air blast sprayer to fully cover the apple clusters with tiny droplets that adhered securely to the fruits without running off. Harvesting took place approximately 2 weeks post application. 20 apples were selected at random from the harvested sections and measured for firmness using a Firmtech firmness and diameter analyzer (BioWorks, Stillwater, Okla.). As shown in FIG. 10, EML treatment increased the firmness of the apples. EXAMPLE 3 Impact of EML on Tomato Storage Life [0078] The EML used in this example was soy EML (Precept™ 8160™) obtained from Solae, LLC (Fort Wayne, Ind.). [0079] [0079]FIG. 11 illustrates the ability of 1000 ppm soy EML aqueous solution to improve vine-ripe tomato fruit storage when applied pre-harvest. Applications of 1000 ppm soy EML were made in July 2003 to mature green tomatoes using a CO 2 backpack sprayer spraying to fully cover the tomato fruit with tiny droplets that adhered securely to the fruits without running off. Harvesting took place approximately 7 days post application. Red ripe fruit remained under light conditions and ambient room temperature for 20 days after harvest with technicians removing unmarketable fruits (fruits showing water-soaking, sour rot, and/or mold). As shown in FIG. 11, EML treatment increased the percentage of total marketable fruit. EXAMPLE 4 Effect of EML on Size, Color and Weight of Fruits and Vegetables [0080] The EML used in this example was soy EML (Precept™ 8160™) obtained from Solae, LLC (Fort Wayne, Ind.). [0081] [0081]FIGS. 12-16 illustrate the sizing and color impact of soy EML applied approximately 2 weeks prior to harvest in Fowler, Calif. on Summer Sweet peaches. 1000 ppm aqueous solution was applied using a hand operated mist sprayer to fully cover the fruit. Applications took place on Jun. 25, 2003, and harvested on Jul. 8, 2003. Color and size measurements were determined using an optical sorting line at the UC-Davis Kearney Agricultural Station in Fresno, Calif. [0082] This was a Single Latin Square design, with each treatment occupying each available treatment position only once. One scaffold, or limb, was assigned a treatment. All treatments occurred once on each of 4 trees. Treatments were applied in late afternoon. Harvest took place on Jul. 8, 2003. Harvesters stripped all treated fruit from each scaffold and transported them to the Kearney Agricultural Station in Fresno, Calif. Each repetition was run through an optical sorting line to separate fruit by color and size. Sizes range from 1 to 10, with 1 being the smallest most unmarketable fruit approximately 1.5 inches in diameter and 10 being the largest and greater than 3.5 inches in diameter. [0083] The effect of soy EML on the percentage of size 3, size 6-7 and size 9 peaches are shown in FIGS. 12, 13 and 14 , respectively. Treated fruit showed a smaller percentage in the low size category (#3) and much larger percentages in the bigger size categories (#6-9). Larger fruit is more valuable, especially when falling in the moderate to large range of #6-7. Color also determines marketability. Treated fruit show higher percentages of fruit with moderate blush (40-100%) (FIG. 15) surface, and with high blush (60-80%) (FIG. 16). [0084] [0084]FIGS. 17-19 illustrate the sizing impact of soy EML, applied approximately 10% color break in Mendota, Calif. on red bell peppers on Jul. 23, 2003. 500 ppm aqueous solution was applied using a hand operated mist sprayer to fully cover the fruit. This was a Randomized Complete Block Design with 8 replications. Application took place in the early morning after sunrise. Temperatures were approximately 72° F. and humidity was approximately 50%. Droplet dwell time was in excess of 30 minutes. As can be seen from FIGS. 17-19, treated fruits were longer, wider, and heavier than the control fruits. [0085] [0085]FIGS. 20 and 21 illustrate the weight and sizing impact of soy EML applied approximately 3 weeks prior to harvest on McIntosh apples in Gays Mills, Wis. 1000 ppm aqueous solution was applied using a hand operated mist sprayer to fully cover the fruit. Application took place on Sep. 9, 2003, and harvested Sep. 30, 2003. This was a Single Latin Square design with each treatment occupying only one quadrant in each of 4 tree replicates. [0086] Applications were made in the mid afternoon with an air temperature of approximately 68° F. and clear skies. Droplet dwell time was in excess of 30 minutes. Treated fruit were larger (diameter) and heavier than the control fruit. As illustrated in FIGS. 20 and 21, respectively, soy EML treatment led to an increase in weight and diameter of the McIntosh apples. EXAMPLE 5 EML Enhances Tuber Size and Yield [0087] The EML used in this example was soy EML (Precept™ 8160™) obtained from Solae, LLC (Fort Wayne, Ind.). [0088] To determine the effect of EML on potato tuber size and yield, a field trial was conducted. Dark Red Norland potato plants, grown at Muck Farms, on muck soil, near Lake Mills, Wis., were sprayed with three levels of EML in aqueous solutions. Crop growth at spray application, two weeks before vine kill and four weeks from harvest, was excellent. Tubers were at a stage of rapid accumulation of food stuffs and were rapidly increasing in size. [0089] Field plot design: Uniform part of the field away from the road or other traffic was selected for these experiments. Single row plots, 20 ft long were used. There were five replicates for each treatment and the plots were separated by single untreated rows to avoid any spray drift. [0090] EML levels tested and spray parameters: Three EML levels, namely EML 100 ppm, 250 ppm and 1000 ppm were applied to plant foliage. No adjuvants were used. There were two spray applications. The first application was about two weeks before vine kill where as the 2 nd application, 10 days later, was only five days before vine killing. [0091] CO 2 powered backpack sprayer, using nozzle providing fine droplet size, was used. Liquid was applied at of 20 gallons/acre. It enabled a good foliar coverage. [0092] Vine killing: About two weeks before harvest, the plants were sprayed with Paraquat herbicide to kill vines and to prepare for harvest. [0093] Harvest: Central 15 ft of the each plot was manually harvested to determine potato yield. All the tubers were collected, dusted off and weighed. After washing and drying, based on their size, the potatoes were classified into <4 oz, 4 to 10 oz and over 10 oz. Each size class was visually further divided, based on their skin color, into premium, acceptable and poor. Potatoes in each class were counted and weighed. Any rotting or damaged potatoes were then discarded. [0094] As shown in Table 4, all three EML levels tested increased potato tuber yield. EML 100 ppm provided the largest marketable yield increase of 36.8%. [0095] As shown in Table 5, all three EML levels tested increased potato tuber size. EML 100 ppm provided the largest increase. TABLE 4 EML application to the foliage of potato plants of cultivar Dark Red Norland enhances tuber yield. Marketable Treatment tuber yield (Lbs/plot) % of untreated control Untreated Control 17.0   100% EML 100 ppm 23.3 136.8% EML 250 ppm 18.9 110.3% EML 1000 ppm 21.6 127.0% [0096] [0096] TABLE 5 EML application to the foliage of potato cultivar dark Red Norland enhances tuber size. Tubers < 4 oz. (expressed Tubers > 4 oz. Treatment as % of total yield) (expressed as % of total yield) Untreated Control 32.8% 67.2% EML 100 ppm 24.2% 75.8% EML 250 ppm 27.2% 72.8% EML 1000 ppm 25.2% 74.8% EXAMPLE 6 EML Enhanced Root Mass [0097] The EML used in this example was soy EML (Precept™ 8160™) obtained from Solae, LLC (Fort Wayne, Ind.). [0098] This example illustrates the ability of EML to promote root growth when incorporated with the sod substrate prior to placement in a hydroponic situation. On Jul. 12, 2003, 3 repetitions of cross-sectional slices measuring 6 inches by 12 inches from a sod mat were placed on a bed of powdered soy EML to coat the root mass. The mats were then placed in a hydroponic solution of ½ strength Hoagland's solution with aeration for 14 days. After 14 days, the mats were removed from solution and three 1-inch slices removed from the mid-section of each mat. The soil was washed from the roots and the shoot portion was sheared at the root shoot interface as to leave only the root portion behind. The root masses were air-dried and then weights taken. The results were shown in Table 6. [0099] In Table 6, each replication consists of three 1-inch by 6-inch cross-section slices of sod from a 6-inch by 12-inch mat in Hydroponic solution. Each replication number is the mean of the raw data root mass in grams of 6 square inches of sod. In all three replications, EML treatment increased the sod root mass. TABLE 6 Sod root mass in grams. Water Control Soy EML Replication 1 2.08 g 3.54 g Replication 2 2.10 g 3.08 g Replication 3 2.45 g 2.65 g Mean 2.21 g 3.09 g EXAMPLE 7 Effect of EML on Root Formation [0100] The EML used in this example was soy EML (Precept™ 8160™) obtained from Solae, LLC (Fort Wayne, Ind.). [0101] [0101]FIGS. 22-24 illustrate the impact of 20 ppm soy EML solution on mung bean root formation. 3.5 cm cuttings were placed in 6-inch test tubes containing solution for 4 days under constant light and approximately 70° F. After 4 days the newly formed roots were counted. Ten replicates were executed. FIGS. 22 and 23 are pictures of control and EML-treated roots at the end of the experiment. FIG. 24 shows the average number of roots in the control and EML-treated group at the end of the experiment. Treated mung bean cuttings showed approximately 50% increase in root number after 4 days of treatment (FIG. 24). EXAMPLE 8 EML Enhanced Pod Set and Seed Yield in Soybean [0102] The EML used in this example was soy EML (Precept™ 8160™) obtained from Solae, LLC (Fort Wayne, Ind.). [0103] In soybeans ( Glycine max L), 43 to 81% of flowers produced fail to produce mature pods due to flower drop, before pollination, or fertilized, immature pod drop (Hansen and Shibles, Agronomy Journal, Vol. 70, January-February, 1978). Over the years, various growth hormones such as ABA, IAA, BAP and GA3 have been tested to enhance the pod set with various levels of success (Mosjidis et al., Annals of Botany 71:193-199, 1993). [0104] To determine the effect of EML on soybean pod set and seed yield, ten field trials were conducted with Glycine max L. soybean. Of these, two were large plot farmer's field trials and all others were small plot replicated field tests. Several different cultivars were used. Test sites had diverse growing conditions, ranging from Brownsville, Tex. to Cedar Falls, Iowa, covering the soybean belt as well as the areas where soybeans are grown only on a small acreage. [0105] In field tests, in Brownville, Tex., the plants were sprayed with various levels of EML, in aqueous solutions, at pre-flowering, early and peak flowering stages of plant development. In the subsequent field tests, based on these data, a single spray at peak flowering of plant growth was applied. [0106] Fieldplot design: In all field tests, wherever possible, uniform part of the field was selected for the experiments. Four row plots, 25 to 30 ft long were used. There were three to five replicates for each treatment. To avoid EML drift to the adjoining plots, only the center two rows were treated and used to record all subsequent data. At farmers field tests, plot size varied from 2 to 8 acres. [0107] EML levels tested and spray parameters: EML levels of 0, 10, 50, 100 and 500 ppm were applied to plant foliage. No adjuvants were used. [0108] CO 2 powered backpack sprayer, using nozzle providing fine droplet size, was used. Liquid was applied at 15 to 50 gallons/acre. It enabled a good foliar coverage. [0109] Pod set data: Pod set data were recorded on ten plants, selected at random, in each replicate about four weeks after the EML spray. All the growing pods on each of the selected plants were counted. [0110] Seed yield data: For seed yield data, the two center rows, treated with EML, were harvested using a combine harvester. Data were calculated based on plot size and compared to the untreated controls. [0111] In all ten field trials, soy EML was effective in increasing the pod set of soybeans. Depending on the specific cultivars, the concentrations of EML that were effective varied somewhat. As an example, the results from a trial conducted in Cedar Falls, Iowa are shown in Table 7 and Table 8. As shown in Table 7, the percentage increase in pod set was higher for cultivar Pioneer 92B38 than cultivar Kruger K-269. All concentrations of EML tested increased the pod set of cultivar Pioneer 92B38. For cultivar Kruger K-269, 10 ppm, 50 ppm and 100 ppm EML increased the pod set while 500 ppm EML did not. [0112] As shown in Table 8, with the exception of 10 ppm EML on cultivar Pioneer 92B38, all concentrations of EML tested increased the seed yield of cultivars Pioneer 92B38 and Kruger K-269. TABLE 7 Soybean field test in Cedar Falls, IA: EML increased pod set of Pioneer92B38 and KrugerK-269 Cultivars. % % Mean Mean of Control of Control # of Pods/Plant # of Pods/Plant Pioneer Kruger Treatment Pioneer 92B38 Kruger K-269 92B38 K-269 Untreated 16.5 27.0 100% 100% EML 10 ppm 22.5 28.0 136% 104% EML 50 ppm 27.5 31.5 167% 117% EML 100 ppm 23.5 30.0 142% 111% EML 500 ppm 26.0 26.0 158%  96% [0113] [0113] TABLE 8 Soybean field test in Cedar Falls, IA: EML increased soybean yield of cultivars Pioneer 92B38 and Kruger K-269. Yield Yield (Bushels/Acre) (Bushels/Acre) Treatment Pioneer Kruger Pioneer Kruger Untreated Control 32.88 23.78 100% 100% EML 10 ppm 32.78 25.24 100% 106% EML 50 ppm 35.18 27.04 107% 114% EML 100 ppm 35.58 25.14 108% 106% EML 500 ppm 33.50 25.64 102% 108% EXAMPLE 9 Effect of EML on Fruit Drop [0114] The EML used in this example was soy EML (Precept™ 8160™) obtained from Solae, LLC (Fort Wayne, Ind.). [0115] [0115]FIG. 25 illustrates the impact of soy EML on fruit drop when applied approximately 3 weeks prior to harvest on McIntosh apples in Gays Mills, Wis. 1000 ppm soy EML aqueous solution was applied using a hand operated mist sprayer to fully cover the fruit. Application took place on Sep. 9, 2003, and harvested Sep. 30, 2003. This was a Single Latin Square design with each treatment occupying only one quadrant in each of 4 tree replicates. [0116] Applications were made in the mid afternoon with an air temperature of approximately 68° F. and clear skies. Droplet dwell time was in excess of 30 minutes. McIntosh apple trees often drop a large portion of their fruit. As shown in FIG. 25, treated fruit showed a much lower fruit drop rate. EXAMPLE 10 Protecting Plants from Stress-Related Injuries [0117] Materials and Methods [0118] The experiments were conducted in growth rooms located at the University of Wisconsin Biotron Facility (2115 Observatory Drive, Madison, Wis. 53706). Each growth room was 10 ft×10 ft where temperature, light quality and photoperiod were controlled. The lights were at about 8 feet above the floor. A solid bank of fluorescent tubes provides lighting, while humidification was provided by steam pipes injected into the intake vents approximately 1 foot below the ceiling on the walls adjacent to the door. The outflow ducts were located directly below the intake vents approximately 1 foot off of the floor. Within these growth rooms the plants were grown on benches approximately 3.5 feet off the floor. [0119] All plants mentioned were grown in 6-inch square plastic (HDPE) pots approximately 6 inches deep with one of several soil-less media as indicated in each individual experiment, unless otherwise noted. The seeds were planted four per pot, uniformly in each corner of the pot into Fafard's Super Fine Germinating Mix soil-less media (Fafard Corp., 1471 Amity Road, Anderson, S.C. 29621). Once planted the pots were placed in a growth room set at 80% relative humidity (RH), 25° C.±2° C., 16 hour photoperiod and 400 uE of light at the top of the canopy. [0120] Soy EML (Precept™ 8160™) was purchased from Solae, LLC (Fort Wayne, Ind.). EML-containing solutions were prepared by mixing EML in water with aggressive agitation until EML was completely dissolved or suspended. Solutions containing specific concentrations of EML as indicated in Tables 9-12 were used to treat plants as described below. [0121] Soy EML was used to make solutions that were applied directly to the vegetative parts of growing plants. To simulate the calcium found in normal tap water, all EML-containing solutions contained 1 mM of CaCl 2 . In some cases, 0.032% Tactic™ (Loveland Industries, Inc., Greeley, Colo.), a combination of an organo-silicone and a synthetic latex, and in others, ethanol, was further added to the EML-containing solution to facilitate wetting of the plant surface by the solution. The solution was applied to the plants by spraying with a hand held, manual spray bottle, similar to those used to dispense household cleaners. [0122] Results [0123] Chilling Stress Alleviation in Field Corn with a Pre-stress Application of EML: Four seeds of Golden Harvest field corn (F-1 hybrid, H-2387) were planted in six-inch square plastic (HDPE) pots. Fourteen days after planting, all the four plants in each pot were sprayed with 500 ppm of EML solution without any adjuvants or with water, which served as control. For each replicate, pots with plants matching in growth and development were selected. To ensure statistical validity, control and treatment were assigned to pots, at random. After spray, the plants were allowed to sit under ambient conditions for six hours before being exposed to the cold stress. Cold stress was initiated at the beginning of night period by dropping the temperature to 0° C. and the day temperature warmed to 25° C. This day/night temperature (25/0° C.) was repeated for four days. At the end of four cycles the plants were returned to their original growing conditions (25/21° C., day/night temperature) and allowed to grow for an additional five days to determine the effect of the cold on growth and vigor. After five days of growth, the plants were harvested at the soil level with a scalpel and fresh weight of each treatment was taken and compared against that of the control pot. In this experiment, using 500 ppm EML, we observed an increase in fresh weight of 5.3% over the control. This would indicate a mitigation, or alleviation, of the cold stress that would allow the treated plants to resume normal growth rates more quickly. [0124] Treatment of Soybean Plants with EML to Alleviate Cold Stress: In this experiment, soybean cultivar KB 241(Kaltenberg Seed Farms, 5506 State Road 19, PO Box 278, Waunakee, Wis. 53597) was used. The soybeans were planted in the six-inch pots, as described earlier, but eight plants per pot, two per corner, uniformly spaced with respect to the four corners. The plants were grown in Scott's 366-P soil-less growing media (Scott's Corp., 14111 Scottslawn Road, Marysville, Ohio 43041) under conditions: 80% RH, 25° C. and 400 uE of light for a fourteen-hour photoperiod in a growth room. Six days after planting the plants were treated with EML in the manner as described above in “Chilling Stress Alleviation in Field Corn with a Pre-stress Application of EML.” In addition to the EML and CaCl 2 , Tactic, a common spray adjuvant, was added at 0.032% to improve wettability of the leaf surface by the spray solution. In this experiment, one half of each pot, four plants, were treated with a control spray and the other four with treatment (EML 500 ppm). Plants in two halves of pots were matched for size, growth and development. The assignment of the treatment and control was at random. Consistent with the previous experiment, the application was made six hours prior to the cold exposure, after which the pots were moved to a growth room under cold (0° C.) conditions for 72 hour. The RH was at 80% and 400 uE of light for a 14-hour photoperiod. At the end of three days the plants were returned to their original growing conditions at 25° C.±2° C., 80% RH and 400 uE of light and harvested after 13 days of growth. Harvest was consistent with that described in “Chilling Stress Alleviation in Field Corn with a Pre-stress Application of EML”: cutting the vegetative portion of the plant at the soil surface with a scalpel and measuring the fresh weight of the plants. In this experiment EML treatment prior to chilling stress led to a fresh weight increase of 22% over the water treated, paired control. This increase is indicative of mitigated stress during the cold period and increased vigor after the stress. [0125] Treatment of Field Corn Plants to Mitigate Drought Stress: Golden Harvest field corn (F1 hybrid, H-2387), planted in six-inch square plastic (HDPE) pots was used. The seeds were planted four per pot, uniformly in each corner of the pot into Scott's 366-P soil-less growing media (Scott's Corp. 14111 Scottslawn Road, Marysville, Ohio 43041). The plants were grown in a greenhouse for twenty days at normal growing conditions (27° C.±2° C. daytime for 14 hours and 23° C.±2° C. nighttime). Humidity was not controlled and six 600 W high pressure sodium lights approximately 4.5 feet above the growing benches were placed to provide supplemental light. These greenhouses are located at the University of Wisconsin Biotron (2115 Observatory Drive, Madison, Wis. 53706). After 20 days of plant growth in pots, drought stress was initiated by withholding water to the pots until two days after visual symptoms of wilting appeared. At this time, each pot was divided into two side-by-side sets of two plants, one side was treated with EML and the other side was treated with water (control). Pots were fully watered to release the stress on plants and were kept under good water conditions for 9 days. Plants were then harvested and fresh weight recorded. As shown in Table 9, 100 ppm and 500 ppm EML treatment following drought stress led to a fresh weight increase of 6.1% and 10.3% respectively over the water treated, paired control. TABLE 9 Fresh weight of corn plants treated with EML to mitigate the drought stress. Data are average of five replicates. Average Mass/Plant Treatment (g) EML (100 ppm) 32.68 Paired water control for the 100 ppm-EML group 30.68 EML (500 ppm) 33.61 Paired water control for the 500 ppm-EML group 30.48 [0126] Mid-Stress Application of EML to Mitigate Drought Stress on Corn Plants: Golden Harvest field corn (F1 hybrid, H-2387) planted in six-inch square plastic (HDPE) pots was used. The seeds were planted four per pot, uniformly in each corner of the pot into Scott's 366-P soil-less growing media (see details in “Treatment of Field Corn Plants to Mitigate Drought Stress” above). All the details in this experiment are the same as described above in “Treatment of Field Corn Plants to Mitigate Drought Stress” except that EML spray application was made at one day after visual wilting was seen as opposed to two days after wilting in “Treatment of Field Corn Plants to Mitigate Drought Stress.” Plants were harvested seven days after the release of water stress. As shown in Table 10, 500 ppm EML treatment following drought stress led to a fresh weight increase of 19.5% over the water-treated, paired control. TABLE 10 Fresh weight of corn plants treated with EML to mitigate the drought stress. Data are average of five replicates. Treatment Mean plant mass (g) EML 500 ppm 25.07 Water Control 20.98 [0127] Mid- and Late-Stress Application of EML to Mitigate Drought Stress in Corn: The experiments above in “Treatment of Field Corn Plants to Mitigate Drought Stress” were repeated with Golden Harvest and Syngenta N60-N2 field corn plants. Details of the experiments and the stress conditions were the same. [0128] Twenty-one day old Golden Harvest and Syngenta N60-N2 field corn plants were treated with 500 ppm EML during and just before the end of the drought stress. Mid-stress application took place after one day of drought stress measured from the time when plants first showed the signs of wilting. The late-stress application took place after 2 days of drought stress measured from the time when plants first showed the signs of wilting. The plants were watered within one hour of the last treatment application. The experiment had four replicates for each treatment. Eight days after stress relief, the plants were harvested and data were collected. [0129] As shown in Table 11, EML application increased biomass in both Golden Harvest and Syngenta N60-N2 corn. This increase was more pronounced in Syngenta N60-N2 corn plants. Application at either mid- or late-drought period was effective. TABLE 11 The effect of EML application in mid-(one day after drought stress) and late-drought (two days after drought stress, which was just before stress relief) stress periods on fresh weight of Golden Harvest and Syngenta N60-N2 corn plants. % increase in fresh weight over control by 500 ppm EML Mid-drought application on Golden Harvest corn plants 13.0% Late-drought application on Golden Harvest corn plants 10.9% Mid-drought application on Syngenta N60-N2 corn plants 28.9% Late-drought application on Syngenta N60-N2 corn plants 22.2% [0130] Pre-stress Application of EML to Mitigate Cold Stress in Cucumbers: Fifteen-day-old Dasher variety cucumbers were treated with 500 ppm EML and 1000 ppm EML before exposing plants to cold stress. Plants were in 6-inch square plastic (HDPE) pots with 2 plants in a pot placed diagonally from each other in opposite corners of the pot. Both plants in the pot were sprayed with the same treatment. There were 6 replicates for each treatment. Plants were sprayed with treatment or water, allowed to dry and then placed in a 1-2° C. cold room in the University of Wisconsin Biotron (room 251B) for 14 to 16 hours. After cold treatment, plants were allowed to grow in normal temperature conditions for 8 days. Plants were then harvested and data were collected. A treatment of cucumber plants with EML at 500 ppm and 1000 ppm before chilling stress gave 3.5% and 16.3% increase in fresh weight respectively compared to water treated control plants. [0131] Post-stress Application of EML to Mitigate Cold Stress in Cucumbers: Experiment in “Pre-stress Application of EML to Mitigate Cold Stress in Cucumbers” was repeated except that the application of EML was made after the cold stress and cold treatment was for a 24-hour period. [0132] Twenty-two day old Dasher cucumber plants were cold stressed by placing them in a 1-2° C. cold room in the University of Wisconsin Biotron (room 251B) for a 24 hour period. Immediately after removal from the cold room, the plants were sprayed with treatment or water control. Twenty days after treatment, plants were harvested and data were collected. At harvest time, the degree of damage and re-growth varied widely. However, EML treatment (500 ppm) gave 90.3% increase in biomass as compared to water treated control plants. [0133] Pre- and Post-stress Application of EML to Mitigate Cold Stress in Melons: Experiments in “Pre-stress Application of EML to Mitigate Cold Stress in Cucumbers” and “Post-stress Application of EML to Mitigate Cold Stress in Cucumbers” were repeated with melons. [0134] Thirteen-day-old Primo melons were treated with 500 ppm EML before or after being exposed to cold stress. At the time of treatment, the plants had one fully expanded leaf and one small leaf. The plants were sprayed with treatment solutions either prior to cold stress or right after cold stress. Cold stress was exposure of plants to 1-2° C. for a 12-hour period. Plants were in 6-inch square HDPE pots with 2 plants in a pot placed diagonally from each other in opposite corners of the pot. Both plants in the pot were sprayed with the same treatment. There were 3 replicates for each treatment. Eight days after treatment, plants were harvested and data were collected. At time of harvest, the degree of damage and re-growth varied widely. At the time of harvest, all of the old leaves showed very little to no damage, all plants had 2-3 new leaves, all seem to be healthy and growing from apical meristem, and flower buds were beginning to form on all plants. EML at 500 ppm was effective at recovery from stress when applications were made after the cold stress exposure (Table 12). TABLE 12 The effect of EML application before and after cold stress on fresh weight of Primo melons. % increase in fresh weight over control by 500 ppm EML EML treatment before cold stress  9.4% EML treatment after cold stress 11.4% [0135] Mitigation of Cold Stress in Tomato Plants: Experiments described in “Pre-stress Application of EML to Mitigate Cold Stress in Cucumbers” and “Post-stress Application of EML to Mitigate Cold Stress in Cucumbers” were repeated with tomatoes. [0136] Fifty-two-day old Florida 47 tomatoes were treated with 500 ppm EML or 1000 ppm EML before exposure to cold stress. At the time of treatment, the plants were about 42-48 cm tall. The plants were arranged in replicates: replicate 1 being the most advanced (at flowering stage) and the tallest and replicate 4 being the least advanced and shortest. Replicates 2 and 3 were in-between. There were paired four replications for water control. After spraying, the plants were allowed to dry and then put into a 1-2° C. cold room for 25 hours. Plants were left in the normal growing conditions for several days after the cold stress. At the time of harvest, the plants were about 55-65 cm tall. The lower (old growth) leaves were all very damaged and many had fallen off but all plants had significant new growth. EML applied at 500 ppm and 1000 ppm gave 4.4% and 12.7% increase in plant biomass over control, respectively. [0137] Although the invention has been described in connection with specific examples, it is understood that the invention is not limited to such specific examples but encompasses all such modifications and variations apparent to a skilled artisan that fall within the scope of the appended claims.

Methods of using modified lecithin to delivery various benefits to plants and plant parts are disclosed. Modified lecithins, applied to growing plants, can cause improvements in fruit and plant firmness, size, color and stability, in economically important fruits and vegetables.

BACKGROUND OF THE INVENTION 1. Technical Field This invention relates to dragline excavating machines which have a main support center pin assembly. Dragline excavation machines are supported on a central stabilization tub during excavating. As such, stress is imparted thereto by the shear weight of the machine and the excavating movements required during use. Such large machines are movable from location to location by use of a walking mechanism that lifts the entire machine up and forward repeatedly imparting increased stress and wear to the center pin and support structure as well as during use in which lateral forces are encountered and the machine pivots on the center pin support structure. 2. Description of Prior Art Prior art support tubs and center pin assemblies can be seen in the following U.S. Pat. Nos. 5,154,012, 5,154,013, 5,676,471. In U.S. Pat. No. 5,154,012 a support tub for a dragline excavating machine is described with a circular tracking ring support and a lifting stool assembly with a center pin lifting pin threadably secured within a bearing support frame. U.S. Pat. No. 5,154,013 is a support tub for a dragline directed to a lifting stool with lifting pivot pin. U.S. Pat. No. 5,676,471 claims a dragline excavator with improved thrust bearing assemblies support upper structure. A center pin connects the upper structure to the lower structure of the support. A perimeter annular rail with rollers provide for rotation of the structure thereabout. SUMMARY OF THE INVENTION A center pin support bearing fitting assembly to pivotally support and maintain a dragline structure on a center support tub during excavating and selectively while moving using a walking mechanism. The center pin support has multiple bearing bore configuration by adding an additional bore bearing support at the center pin base spaced in relation to the primary support bores within the support bearing fitting assembly within the center support tub frame of the dragline. DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a center pin support bearing fitting illustrating multiple bore support elements of the invention. FIG. 2 is a cross-sectional view on lines 2 - 2 of FIG. 1 . FIG. 3 is a cross-sectional view of the center support bearing assembly of the invention with a center pin positioned therewithin. FIG. 4 is a cross-sectional view of a prior art center pin bearing bore assembly. DETAILED DESCRIPTION OF THE INVENTION A dragline excavator center pin bearing support assembly 10 of the invention can be seen in FIGS. 1 and 2 of the drawings. The dragline center pin support assembly 10 has an annular pivot pin housing 11 which is positioned within a dragline excavator tub (not shown). The housing 11 has an annular base plate 12 with an upstanding perimeter annular sidewall 13 . A top wall 14 extends from the sidewall 13 radially upwardly to a primary bearing fitting 15 in which a center pivot retention pin 16 extends as seen in FIG. 3 of the drawings. The primary bearing fitting 15 has a center bore 17 therethrough with an upper pin receiving opening at 17 A and a lower pin exit opening at 17 B. The bearing fitting 15 has an area of reduced internal bore dimension at 18 adjacent the lower exit bearing opening 17 B which will be described in greater detail hereinafter. The bearing fitting 15 is positioned on and supported by an annular sleeve 19 with a horizontally extending stabilization frame plate 20 extending radially therefrom. The annular support sleeve 19 extends from and is supported by a raised central bearing platform 21 on the base plate 12 and is in vertical alignment with the hereinbefore described lower bore exit opening 17 B. The annular support sleeve 19 has multiple power line access openings at 22 annularly spaced thereabout as best seen in FIG. 1 of the drawings. The central bearing fitting 15 is preferably of a cast monolithic construction and defines two bearing guide engagement surfaces within the bore 17 . The first bearing guide surface within the bore 17 is its interior annular wall surface 23 extending from the upper pin receiving opening at 17 A. A second bearing guide engagement surface 24 is defined by the hereinbefore described area of reduced interior bore diameter at 18 . It will be evident from the above description that as illustrated best in FIG. 3 of the drawings the center pivot retention pin 16 is engaged by the first bearing guide surface annular wall 23 therealong and the second bore guide engagement surface 24 adjacent thereto as noted. Referring back now to FIG. 1 of the drawings the raised central bearing platform 21 is of a solid monolithic construction and has a central annular center pin receiving recess 25 therewithin which defines a stabilization bearing pocket for the base of the center pivot retaining pin 16 . The center retaining pin 16 shown in this example is of a cast construction having an outer upper and lower bearing surfaces 26 and 27 respectively of different annular diameter. A bore at 28 extends longitudinally therethrough with at least one horizontally disposed opening at 29 extending through the lower surface 27 . It will be evident from the above description that the geometry of the center pivot retaining pin 16 defines that the upper and lower bearing surface portions 26 and 27 are of different wall thicknesses induced thereby. The center pin 16 provides a pivot access and retention for the dragline (not shown) to prevent unintended lateral movement thereof as will be well understood within the art. The base of the center pivot retaining pin 16 is registerably received within the recess 25 of the bearing platform 21 which in combination with the hereinbefore described first and second bearing surfaces in the primary bearing fitting 15 reduces extraneous wear and increases the working life of the assembly. Comparison to prior art designs which can be seen in FIG. 4 of the drawings, prior art typically relies only on a center pin support assembly 30 having a prior art center pin 31 retained within a prior art center cast bearing fitting 32 defining two guide bearing surfaces 33 and 34 (bores) therewithin. The prior art pin 31 simply extends downwardly without any additional translateral support thus imparting additional wear and eventual failure to the limited prior art bearing surfaces of the central pin and support assembly 30 . If will therefore be evident that the present invention by having a central stabilization pin receiving bearing pocket recess 25 within the base plate 21 increases the useful product life of the assembly. It will thus be seen that a new and improved center pin support bearing and guide fixture has been illustrated and described and it will be apparent to those skilled in the art that various changes and modifications may be made thereto without departing from the spirit of the invention.

A center pivot pin support bearing assembly to provide rotatable center restraint for a dragline excavator machine. Multiple center pin bearing support fittings imparts stabilization and additional bearing wear surfaces for increased pin useful service life before replacement. An axially center pin bore receiving fitting is provided for longitudinal spaced multiple support fits combination with a center pin receiving stabilization base and fit.

BACKGROUND OF THE INVENTION The present invention relates to balers for forming cylindrical bales from a crop and more specifically relates to the starter roll located at the bale forming chamber inlet of such a baler. Balers for the formation of so-called round bales are used for baling various types of crops under varied harvesting conditions. Depending on the strength, the moisture content and the size of the stalks of the particular crop, there are variations in their behavior during the conveying and baling process. Nevertheless, it is desirable to be able to bale all crops under the most varied conditions with a single baler. Starter rolls of some known balers, like that disclosed in U.S. Pat. No. 4,428,282 for example, have a smooth, metallic crop-engaging surface which performs satisfactorily under most crop conditions to set the crop into rotation for forming a cylindrical core upon which additional crop is wrapped during the baling process. In order to get more aggressiveness for aiding in more difficult crop conditions, in particular when baling crop for silage feed, it is known to provide the crop-engaging surface of the starter roll with helical impellers. Beyond that it has become known that the roller should be provided with moldings or ribs oriented parallel to the axis of rotation for performing a moderately aggressive conveying effect upon the crop. It is further known that these ribbed rollers may be rubber-coated to increase their aggressiveness against the crop, such ribbed and coated rollers being disclosed in U.S. Pat. No. 4,426,926 granted on Jan. 24, 1984. All of the previously described balers operate satisfactorily with the majority of crops and under most harvesting conditions; however, under unfavorable conditions very dry crop is not carried along by the roller and may slide past it and lead to clogging. The problem underlying the invention is seen as that of proposing a baler for baling cylindrical bales from a crop, with a bale forming chamber having an inlet at its underside, the inlet having a starter roll positioned therein for aiding in the rolling up of crop products entering the inlet and the starter roll being adaptable to a multitude of crops and baling conditions including dry crop conditions. SUMMARY OF THE INVENTION According to the present invention, there is provided an improved starter roll design which is adaptable for working efficiently in various baling and crop conditions. A broad object of the invention is to provide a starter roll having appropriate exterior features and composition for effectively carrying and orienting crop being rolled into a cylindrical bale. A more specific object of the invention is to provide a starter roll designed for having its exterior altered by the addition or elimination of exterior features and composition to in order for being more suited to aiding in the baling process of a given crop under a given condition. The above objects are accomplished by providing starter rolls which are adapted for having impellers or ribs releasably attached to the exterior thereof at diametrically spaced locations, the ribs extending lengthwise of the roll; or by providing starter rolls which are adapted for having semi-cylindrical shells attached thereabout. In both cases, the added structures are constructed of or coated with aggressive, wear resistant material such as rubber or the like. These and other objects will become apparent from a reading of the following description together with the appended drawings. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a right side elevational view of a baler embodying a starter roll which is particularly suited for benefiting from the present invention. FIG. 2 is a front view of a first embodiment of an exterior feature that may be releasably attached to a starter roll for modifying the aggressiveness thereof. FIG. 3 is a front view of a second embodiment of an exterior feature that may be releasably attached to a starter roll for modifying the aggressiveness thereof. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown a baler 10 for making large cylindrical bales of straw, hay, grass or similar crops that are deposited in windrows on a field or are cut there. The baler 10 is composed generally of a frame 12 having a pickup arrangement 14 attached thereto beneath a bale forming chamber 16 having an inlet at its bottom in which is positioned a bale starter roll 18. The frame 12 is supported on a pair of ground wheels 20 and includes opposite side walls 22 and a draft tongue 24 for connection to the drawbar of an agricultural tractor. The pickup 14 includes circulating teeth 26 that take up the crop deposited on the ground in windrows and transports it to the bale forming chamber 16. In FIG. 1, and hence in its initial condition, the bale forming chamber takes the form of a wedge that is delimited on front and rear sides by separate runs of a set of belts 28. The set of belts 28 are arranged side-by-side and run over a plurality of rolls 30. One or more of the rolls 30 are brought into rotation through a drive arrangement 32 from the agricultural tractor, and move the belts 28 in a particular direction. The belts 28 are put under tension by a tensioning device 34 that yieldably resists the expansion of the bale chamber 16 as the bale grows therewithin. As can be seen in FIG. 1, crop is delivered to the bale forming chamber 16 and is brought into rotation by the separate runs of the belts which travel in opposite directions in order to form the core of a bale. During operation across the field, more and more crop is transported to the bale forming chamber 16 so that the core of the bale enlarges and causes the chamber to expand against the resisting force of the tensioning device 34. The segments of the belts 28 forming the chamber 16 can lengthen under increased tension at the tensioning device 34 until the bale forming chamber 16 has taken up nearly all the space between the side walls 22 at which time the baler is stopped so that no further crop enters the chamber before the bale is wrapped and ejected, in a well known manner. The roller 18 is located in the lower region of the bale forming chamber 16, extends lengthwise between the two side walls 22, is oriented parallel to the axis of the rolls 30, does not change its position during the baling process, always moves near the surface of the belts 28 and is also driven by the drive arrangement 32. Due to its location, the roll 18 assists in the initial phase of the baling process by assisting bringing the crop into rotation in the initially empty baling chamber 16 in order to form the core of the bale. For this purpose, it moves in a direction opposite that of the adjacent run of the belts 28. The embodiments of the rolls 18 according to FIGS. 2 and 3 have the common feature that metal impellers or ribs 36 are fixed, as by welding, to the surface of the cylindrical core of the roll in a similar arrangement. Specifically, the impellers 36 are arranged in double rows that converge to arrow points, and are spaced axially so as to leave spaces 38. The impellers 36 do not extend over the entire circumference of the roll 18, but are interrupted at two diametrically opposite places and leave between them a slot 42 directed parallel to the axis of rotation of the roller 18, in which region several threaded holes 44 are located. According to FIG. 2, each slot 42 between the helically arranged impellers 36 is filled by a straight impeller 36', configured as a rib or molding and oriented parallel to the axis of rotation of the roller 18, and attached by screws 48 received in the holes 46. This impeller 36' is provided with a coating 40 on those of its surfaces that are not in contact with the roll 18. The impeller 36' could alternatively be made entirely of a material having requisite wear resistance and frictional characteristics. In the embodiment according to FIG. 3, each impeller 36' is eliminated and replaced by a shell 50 that is also attached by screws 48 in the same threaded holes 44. Both shells 50 are semi-cylindrical so that they encompass a 180° arc and cover the entire circumference of the roller 18 including the impellers 36 which remain in place. The outer surfaces of the shells 50 are covered with the aforementioned coating of rubber or other substance having the requisite wear resistance and frictional properties. The advantage of the detachable impellers 36' or the shells 50 lies in the fact that those parts made of, or covered with a coat of, a substance that is wear resistant and which increases the aggressiveness of the roll can be attached or detached selectively as required in order to match the aggressiveness of the roll to the crop and/or harvest conditions. While the rolls 18 are here shown having the impellers 36 arranged in a particular way, it should be understood that impellers having a variety of arrangements for producing desired aggressiveness may be used with the only requirement being that the impeller arrangements be such as to leave space for the detachable impellers to be fixed to the cylindrical core of the roll.

The starter roll of a baler for rolling crop products into a large cylindrical bale has, in accordance with a first embodiment, a pair of ribs coated with or made of rubber or another friction enhancing material that are releasably attached to the roll for increasing its aggressiveness. In another embodiment, the roll has a pair of cylindrical shells releasably secured thereabout, the shells being coated with rubber or another friction enhancing material for increasing its aggressiveness.

BACKGROUND OF INVENTION In a redundant power supply system, electrical power is supplied by a plurality of power supplies electrically connected in parallel to one another. Generally, a desired system power requirement can be obtained by utilizing the combined output of N power supplies. By adding one additional backup power supply, resulting in N+1 power supplies in the power supply system, the system can electrically remove a failed power supply to avoid a power disruption and still meet the desired system power requirement of N power supplies. Monitoring circuits have been developed that monitor the operation of a power supply by measuring a DC voltage at an output terminal on the power supply. However, a drawback with the other monitoring circuits is that the power supply may be malfunctioning for a relatively large amount of time before the fault condition causes a voltage or current variance at a power supply output terminal that is detected by the monitoring circuit. Thus, there is a need for a monitoring system that can detect operational fault conditions in a power supply utilizing internal signals generated by the power supply, instead of merely monitoring a voltage at a power supply output terminal. Internal signals of a power supply are defined as any signal, such as a pulse width modulation signal for example, generated within a power supply to subsequently generate an output voltage at an output terminal of the power supply. SUMMARY OF INVENTION A method for detecting an operational fault condition in a power supply in accordance with an exemplary embodiment. The power supply has a controller operably coupled to first and second switches. The first and second switches are connected in series between a voltage source and a ground node, wherein a first electrical node is electrically coupled between the first and second switches. The first electrical node is further electrically coupled to a first end of an inductor. The controller is configured to induce the first and second switches to apply voltage pulses to the first electrical node. The method includes monitoring a voltage at the first electrical node to determine a number of voltage pulses being applied to the first electrical node over a predetermined time interval. The method further includes determining when a first operational fault condition has occurred when the number of voltage pulses being applied to the first electrical node over the predetermined time interval is less than or equal to a predetermined number of voltage pulses. A system for detecting an operational fault condition in a power supply in accordance with another exemplary embodiment is provided. The power supply has a controller operably coupled to first and second switches. The first and second switches are connected in series between a voltage source and a ground node, wherein a first electrical node is electrically coupled between the first and second switches. The first electrical node is further electrically coupled to a first end of an inductor. The controller is configured to induce the first and second switches to apply voltage pulses to the first electrical node. The system includes a voltage pulse detection circuit operably coupled to the first electrical node that determines the number of voltage pulses being applied to the first electrical node over a predetermined time interval, the voltage pulse detection circuit generating a first signal indicating that a first operational fault condition has occurred when the number of voltage pulses being applied to the first electrical node over the predetermined time interval is less than or equal to a predetermined number of voltage pulses. A system for detecting an operational fault condition in a power supply in accordance with another exemplary embodiment is provided. The power supply has a controller operably coupled to first and second switches. The first and second switches are connected in series between a voltage source and a ground node, wherein a first electrical node is electrically coupled between the first and second switches. The first electrical node is further electrically coupled to a first end of an inductor. The controller is configured to induce the first and second switches to apply voltage pulses to the first electrical node. The method includes a means for monitoring a voltage at the first electrical node to determine a number of voltage pulses being applied to the first electrical node over a predetermined time interval. The method further includes a means for determining when a first operational fault condition has occurred when the number of voltage pulses being applied to the first electrical node over the predetermined time interval is less than or equal to a predetermined number of voltage pulses. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic of a power supply system; FIG. 2 is a more detailed schematic of a power supply in the power supply system of FIG. 1 having a diagnostic system in accordance with an exemplary embodiment; FIG. 3 is a detailed schematic of a voltage pulse detection circuit utilized in the power supply of FIG. 2 ; FIG. 4 is a voltage level detection circuit utilized in the power supply of FIG. 2 ; FIG. 5 is a schematic of a signal generated by a pulse width modulation controller at a node 64 of FIG. 2 ; FIG. 6 is a schematic of a signal generated at a node 82 of the voltage pulse detection circuit of FIG. 3 ; FIG. 7 is a schematic of a first operational fault signal generated by the voltage pulse detection circuit of FIG. 2 ; FIG. 8 is a schematic of a signal generated at a node 66 of the power supply of FIG. 2 ; FIG. 9 is a schematic of a second fault signal generated by a voltage level detection circuit of FIG. 2 ; FIG. 10 is a schematic of a signal generated by a logic gate of the low-voltage detection circuit of FIG. 2 . DETAILED DESCRIPTION Referring to FIG. 1 , a power supply system 10 for generating electrical power is illustrated. The power supply system 10 includes power supplies 12 , 14 , 16 , a load 18 , electrical lines 20 , 22 . As shown, each of the power supplies 12 , 14 , 16 and the load 18 are electrically coupled in parallel via electrical lines 20 , 22 . Because power supplies 12 , 14 , 16 have substantially similar circuitry, only power supply 12 will be explained in greater detail below. It should be noted, that the system for detecting fault conditions in the power supply system 10 , which will be explained below, can be utilized with circuitry used in any switch mode power supplies. Referring to FIG. 2 , a detailed schematic of the power supply 12 is illustrated. The power supply system 12 comprises a buck topology switching power supply system. The power supply 12 includes a voltage source 30 , a pulse-width modulation (PWM) controller 32 , switches 34 , 36 , an inductor 38 , a capacitor 40 , a switch 42 , a bias power supply 44 , a voltage pulse detection circuit 46 , a voltage level detection circuit 48 , and a logic gate 50 . The voltage source 30 supplies a DC voltage between nodes 60 , 62 . The switches 34 , 36 provide voltage pulses using a voltage from the voltage source 30 that are applied to the inductor 38 . The switch 34 is electrically coupled between a node 60 and a node 64 . The switch 36 is electrically coupled between the node 62 and the node 64 . The switches 34 , 36 are also operably coupled to the PWM controller 32 . The PWM controller 32 generates control signals that induce the switches 34 , 36 to open and close to generate voltage pulses for the inductor 38 . Further, the plurality of voltage pulses are applied at a predetermined frequency at the node 64 . The PWM controller 32 can vary the duty cycle of the voltage pulses to adjust a DC output voltage at the node 66 to a predetermined level. The inductor 38 is operably coupled between a node 64 and the node 66 coupled to the capacitor 40 . The capacitor 40 is electrically coupled between the node 66 and the node 62 . The combination of the inductor 38 and the capacitor 40 converts the voltage pulses applied to the node 64 to a DC voltage at a predetermined voltage level at the node 66 . The switch 42 is operably coupled between the node 66 and the electrical line 20 . The switch 42 further is operably coupled to the logic gate 50 . When either the voltage pulse detection circuit 46 or a voltage level detection circuit 48 detects an operational fault condition, the logic gate 50 transmits a signal (F 3 ) to the switch 42 having a high logic level. In response, the switch 42 moves to an open operational position to prevent current from flowing from the inductor 38 and/or capacitor 40 to the load 18 . Alternately, when neither the voltage pulse detection circuit 46 nor the low-voltage detection circuit 48 detects an operational fault condition, the logic gate 50 transmits a signal (F 3 ) to the switch 42 having a low logic level. In response, the switch 42 moves to a closed operational position to supply current from the inductor 38 and/or capacitor 40 to the load 18 . The bias power supply 44 is operably coupled between the node 60 and the node 62 to supply a voltage to the voltage pulse detection circuit 46 and the voltage level detection circuit 48 . The bias power supply 44 is electrically coupled to both the circuit 46 and the circuit 48 at a node 68 . The bias power supply 44 is further electrically coupled to the circuit 46 and the circuit 48 at a node 70 . Referring to FIG. 3 , the voltage pulse detection circuit 46 is provided to detect when either of switches 34 , 36 are stuck in an open or closed operational position, that is indicative of a first fault condition of the power supply 12 . When such a condition occurs, one or more voltage pulses that should be detected at the node 64 are not detected. The voltage pulse detection circuit 46 includes a comparator 80 , a resistor 84 , a capacitor 86 , and a diode 88 . A non-inverting terminal (+) of the comparator 80 is electrically coupled to a node 82 and an inverting terminal (−) of the comparator 80 receives a reference voltage (VREF 1 ). The resistor 84 is electrically coupled between the node 68 and the node 82 . Further, a diode 88 is electrically coupled between the node 82 and the node 64 . Finally, a capacitor 86 is electrically coupled between the node 82 and the node 70 . When a voltage pulse at the node 64 has a high logic value, electrical current flows through the resistor 84 to the capacitor 86 to charge the capacitor 86 . As the capacitor 86 charges, a voltage increases at the node 82 . When the voltage at node 82 becomes greater than the voltage (VREF 1 ), the comparator 80 generates a fault signal (F 1 ) having a high logic level that is transmitted to the logic gate 50 . The time constant of the resistor 84 and the capacitor 86 is greater than one or more periods of the voltage pulses being applied to node 82 at a predetermined frequency. This time constant ensures that noise and other perturbations will not cause false triggering of a fault condition. In the exemplary embodiment, the time constant of the resistor 84 and the capacitor 86 is equal to the time duration of a time period from a time (T 3 ) to a time (T 7 ) representing three time periods of the voltage pulses. Thus, in the exemplary embodiment, when the three voltage pulses are not detected at the node 64 , the comparator 80 generates the fault signal (F 1 ) having the high logic level. Alternately, when the voltage at node 82 is less than the voltage (VREF 1 ), the comparator maintains the fault signal (F 1 ) at a low logic level indicating that the first fault condition has not been detected. Referring to FIG. 4 , the voltage level detection circuit 48 is provided to detect when an output voltage at the node 66 is below a predetermined threshold voltage that is indicative of a second fault condition of the power supply 12 . The second fault condition can occur when the switch 36 is electrically shorted, which induces the voltage at the node 66 to fall below the threshold voltage (VREF 2 ). The voltage level detection circuit 48 includes a comparator 90 having a non-inverting terminal (+) and an inverting terminal (−). The inverting terminal (−) is electrically coupled to the node 66 . The non-inverting terminal (+) receives the reference voltage (VREF 2 ). When a voltage applied to the node 66 falls below the reference voltage (VREF 2 ), the comparator 90 outputs a second fault signal (F 2 ) having a high logic level that is indicative of a second fault condition of the power supply 12 . The logical OR gate 50 is operably coupled to the voltage pulse detection circuit 46 and to the voltage level detection circuit 48 and receives the first and second fault signals (F 1 ), (F 2 ) from the circuits 46 , 48 , respectively. When either of the signals (F 1 ), (F 2 ) have a high logic level, the gate 50 generates a fault signal (F 3 ) having a high logic level which is transmitted to the switch 42 . In response, the switch 42 moves to an open operational position to stop the flow of current from the power supply 12 through the electrical line 20 . When both of the signals (F 1 ), (F 2 ) have a low logic level, the gate 50 generates a fault signal (F 3 ) having a low logic level that is transmitted to the switch 42 . In response, the switch 42 moves to a closed operational position to allow current to flow through the electrical line 20 from the power supply 12 . Referring to FIGS. 3 , 5 – 7 , the detection of fault conditions within the power supply 12 will now be explained. The PWM controller 64 induces the switches 34 , 36 to generate the voltage pulses 110 , 112 , 114 , and 116 . As shown, each of the pulses 110 , 112 , 114 comprise a high logic level with a time duration of (ΔT 1 ) indicative of normal operation of the power supply 12 . The voltage pulse 116 has a high logic level with the time duration equal to that of two voltage pulse periods. In other words, one additional voltage pulse that should be present was not detected. However, since the voltage at the node 82 of the comparator 90 never exceeds the reference voltage (VREF 1 ), the voltage pulse detection circuit 70 does not generate a fault signal having high logic value. Thereafter, the switches 34 , 36 generate the voltage pulse 117 having a high logic level having a time duration equal to that of three voltage pulse periods. Because the voltage at the node 82 exceeds the reference voltage (VREF 1 ) between time (T 6 ) and time (T 7 ), the comparator 90 generates a first fault signal (F 1 ) having a high logic value during this time interval. In response to the signal (F 1 ), the logic gate 50 generates a fault signal (F 3 ) having a high logic value that induces the switch 42 to move to an open operational position. Thus, when at least three missing pulses are detected at the node 64 , the switch 42 is moved to an open operational position to prevent current flow from the power supply 12 to the electrical line 20 . Referring to FIGS. 4 , and 8 – 10 , between times (T 4 ) and (T 5 ), the voltage at node 66 is less than the reference voltage (VREF 2 ). In response, the comparator 90 of the voltage level detection circuit 48 generates a second fault signal (F 2 ) having a high logic value during the time interval from (T 4 ) to (T 5 ). In response to the signal (F 2 ), the logic gate 50 generates the third fault signal (F 3 ) having a high logic level that induces the switch 42 to move to an open operational position. When a voltage greater than a reference voltage (VREF 2 ) is detected at the node 66 , the switch 42 is moved to an open operational position to prevent current flow from the power supply 12 to the electrical line 20 . The system and method for detecting operational fault conditions in a power supply provides a substantial advantage over other systems and methods. In particular, the system and method provide a technical effect of detecting operational fault conditions in a power supply utilizing internal signals generated by the power supply, instead of merely monitoring an output voltage of the power supply. Thus, the inventive system allows fault conditions to be detected more quickly than other systems, to prevent a disruption of electrical power to the load 18 . While the invention is described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalence may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to the teachings of the invention to adapt to a particular situation without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the embodiment disclosed for carrying out this invention, but that the invention includes all embodiments falling within the scope of the intended claims. Moreover, the use of the term's first, second, etc. does not denote any order of importance, but rather the term's first, second, etc. are used to distinguish one element from another.

A system and a method for detecting an operational fault condition in a power supply are provided. The power supply has a controller operably coupled to first and second switches. The first and second switches are connected in series between a voltage source and a ground node, wherein a first electrical node is electrically coupled between the first and second switches. The first electrical node is further coupled to a first end of an inductor. The controller is configured to induce the first and second switches to apply voltage pulses to the first electrical node. The method includes monitoring a voltage at the first electrical node to determine a number of voltage pulses being applied to the first electrical node over a predetermined time interval. The method further includes determining when a first operational fault condition has occurred when the number of voltage pulses being applied to the first electrical node over the predetermined time interval is less than or equal to a predetermined number of voltage pulses.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a National Stage of International Application No. PCT/JP2015/057264 filed Mar. 12, 2015, claiming priority based on Japanese Patent Application No. 2014-064381 filed Mar. 26, 2014, the contents of all of which are incorporated herein by reference in their entirety. TECHNICAL FIELD The present invention relates to a method for producing water-absorbent resin particles. BACKGROUND ART Water-absorbent resin particles are mainly used for disposable diapers, sanitary napkins, incontinence pads, pet sheets, water-retaining materials for soil, water-blocking materials for power cable, dew condensation prevention agents, and the like. Absorbent articles, for example, disposable diapers, are typically formed such that an absorbent material composed of water-absorbent resin particles and hydrophilic fibers is sandwiched between a liquid-permeable sheet to be in contact with the body and a liquid-impermeable sheet provided on the opposite side. The absorbent material is produced, for example, by allowing a mixture including water-absorbent resin particles and crushed hydrophilic fiber to be layered on a metal mesh by means of an air flow, and then, allowing the layered product to be compressed by pressing. Examples of known water-absorbent resin particles include hydrolysates of starch-acrylonitrile graft copolymers, neutralized products of starch-acrylic acid graft copolymers, saponified products of vinyl acetate-acrylic acid ester copolymers, crosslinked products of partially neutralized polymers of acrylic acid, and partially neutralized polyacrylic acids. The water-absorbent resin particles used in absorbent materials are required to exhibit not only an excellent water-absorption capacity and water-retention capacity, but also suitable particle size and narrow particle size distribution. When particles with a large particle size are dominantly present, the absorbent material, when compressed, is likely to become hard. When particles with a small particle size are dominantly present, the particles pass through the metallic mesh in the process of producing the absorbent material; thus, such particles are not preferable. Specifically, the water-absorbent resin particles used in absorbent materials are desired to have a median particle size suitable for the design of the intended absorbent materials or absorbent articles, and narrow particle size distribution. From the standpoint of high performance of the resulting water-absorbent resin particles and the simplicity of the production method, polymerization of a water-soluble ethylenically unsaturated monomer is the mainstream method for producing water-absorbent resin particles. Examples of the polymerization method include an aqueous solution polymerization method comprising polymerizing an aqueous solution of a water-soluble ethylenically unsaturated monomer to obtain a water-containing gel, milling the gel, and drying the gel; and a reversed-phase suspension polymerization method comprising dispersing a water-soluble ethylenically unsaturated monomer in the presence of a dispersion stabilizer in an organic dispersion medium, such as a hydrocarbon dispersion medium, for suspension polymerization to thereby obtain a water containing-gel, dehydrating the gel, and drying the gel. In the aqueous solution polymerization method, the water-containing gel obtained after polymerization is in the form of viscous block-shaped material, which therefore make the milling step and drying step complicated, increasing the likelihood of the generation of fine particles in the milling step; this lowers the possibility of obtaining water-absorbent resin particles with a suitable particle size and narrow particle size distribution. In the reversed-phase suspension polymerization method, however, it is possible to control the size of the particles by adjusting the size of the droplets of the water-soluble ethylenically unsaturated monomer dispersed in a dispersion medium. Thus, there has been proposed a variety of techniques for controlling the particle size based on the reversed-phase suspension polymerization method. Examples of proposed techniques for achieving narrow particle size distribution include a polymerization method performed under reduced pressured using a sorbitol fatty acid ester as a dispersion stabilizer (Patent Literature 1), a method using a sorbitan fatty acid ester with an HLB of 8 to 12 as a dispersion stabilizer (Patent Literature 2), and a method using a polyglycerol fatty acid ester as a dispersion stabilizer (Patent Literature 3). However, even these techniques have not been capable to provide water-absorbent resin particles that exhibit satisfactory performance from the standpoint of excellent water-absorption ability, suitable particle size, and narrow particle size distribution. PRIOR ART LITERATURE Patent Literature Patent Literature 1: JPS56-26909A Patent Literature 2: JPS56-131608A Patent Literature 3: JPS62-172006A SUMMARY OF INVENTION Technical Problem An object of the present invention is to provide a method for producing water-absorbent resin particles that exhibit a suitable particle size and narrow particle size distribution as well as an excellent water-absorption ability, and that can suitably be used in absorbent articles and the like. Solution to Problem The present inventors found that in producing water-absorbent resin particles through reversed-phase suspension polymerization, the use of an organic acid monoglyceride as a dispersion stabilizer can provide water-absorbent resin particles that exhibit a suitable particle size and narrow particle size distribution as well as an excellent water-absorption ability, and that can suitably be used in absorbent articles and the like. The inventors then completed the invention. Specifically, the present invention relates to a method for producing water-absorbent resin particles by subjecting a water-soluble ethylenically unsaturated monomer to reversed-phase suspension polymerization in a dispersion medium, the method comprising performing the reversed-phase suspension polymerization in the presence of an organic acid monoglyceride. Specifically, the present invention includes, for example, the subject matter described in the following items. Item 1. A method for producing water-absorbent resin particles by subjecting a water-soluble ethylenically unsaturated monomer to reversed-phase suspension polymerization in a dispersion medium, the method comprising performing the reversed-phase suspension polymerization in the presence of an organic acid monoglyceride. Item 2. The method for producing water-absorbent resin particles according to Item 1, wherein the reversed-phase suspension polymerization is performed in the presence of an organic acid monoglyceride having one ester group in which a fatty acid having 10 to 18 carbon atoms is ester-bonded with one hydroxyl group of the glycerol, and one or two ester groups in which an organic acid having 2 to 8 carbon atoms is ester-bonded with one or two hydroxyl groups of the glycerol. Item 3. The method for producing water-absorbent resin particles according to Item 2, wherein the fatty acid having 10 to 18 carbon atoms is at least one member selected from the group consisting of capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid. Item 4. The method for producing water-absorbent resin particles according to Item 2 or 3, wherein the organic acid having 2 to 8 carbon atoms is at least one member selected from the group consisting of acetic acid, lactic acid, citric acid, succinic acid, and diacetyl tartaric acid. Item 5. The method for producing water-absorbent resin particles according to any one of Items 1 to 4, wherein the organic acid monoglyceride is at least one member selected from the group consisting of glyceryl monolaurate acetate, glyceryl monostearate acetate, glyceryl monostearate lactate, glyceryl monostearate citrate, and glyceryl monooleate citrate. Item 6. The method for producing water-absorbent resin particles according to any one of Items 1 to 5, wherein the amount of the organic acid monoglyceride is 0.1 to 30 parts by mass per 100 parts by mass of the water-soluble ethylenically unsaturated monomer. Item 7. The method for producing water-absorbent resin particles according to any one of Items 1 to 6, wherein the reversed-phase suspension polymerization is performed in the presence of a radical polymerization initiator. Item 8. The method for producing water-absorbent resin particles according to any one of Items 1 to 7, wherein the dispersion medium is a hydrocarbon dispersion medium (preferably, a hydrocarbon containing at least one member selected from the group consisting of n-hexane, n-heptane, cyclohexane, and isomers thereof). Item 9. The method for producing water-absorbent resin particles according to any one of Items 1 to 8, the method comprising, after the reversed-phase suspension polymerization, adding a crosslinking agent to perform post-crosslinking. Item 10. The method for producing water-absorbent resin particles according to any one of Items 1 to 9, wherein the water-soluble ethylenically unsaturated monomer is at least one member selected from the group consisting of (meth)acrylic acid, salts thereof, (meth)acrylamide, and N,N-dimethyl(meth)acrylamide (preferably (meth)acrylic acid and salts thereof). Advantageous Effects of Invention The present invention can produce, by using an organic acid monoglyceride as a dispersion stabilizer, water-absorbent resin particles that exhibit a suitable particle size and narrow particle size distribution as well as an excellent water-absorption ability, and that can suitably be used in absorbent articles and the like. DESCRIPTION OF EMBODIMENTS A feature of the method for producing water-absorbent resin particles of the present invention is that in the method for producing water-absorbent resin particles by subjecting a water-soluble ethylenically unsaturated monomer to reversed-phase suspension polymerization in a dispersion medium, the reversed-phase suspension polymerization is performed in the presence of an organic acid monoglyceride. In the reversed-phase suspension polymerization, a multistep polymerization including two or more steps can be performed by further adding a water-soluble ethylenically unsaturated monomer to the water-absorbent resin particles obtained by reversed-phase suspension polymerization. In the multistep polymerization including two or more steps, the particle size of the resulting water-absorbent resin particles can be increased by allowing the particles obtained in the reversed-phase suspension polymerization of the first step to agglomerate. This makes it easier to achieve a particle size suitable for absorbent articles, such as disposable diapers. Examples of water-soluble ethylenically unsaturated monomers for use in the present invention include (meth)acrylic acid (in this specification, “acrylic” and “methacrylic” are collectively referred to as “(meth)acrylic”; the same applies hereinafter) and salts thereof; 2-(meth)acrylamide-2-methylpropane sulfonic acid and salts thereof; nonionic monomers, such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, 2-hydroxyethyl(meth)acrylate, N,N-methylol(meth)acrylamide, and polyethylene glycol mono(meth)acrylate; and amino group-containing unsaturated monomers, such as N,N-diethylaminoethyl(meth)acrylate, N,N-diethylaminopropyl(meth)acrylate, and diethylaminopropyl(meth)acrylamide, and quaternary compounds thereof. These water-soluble ethylenically unsaturated monomers may be used alone, or in a combination of two or more. Of the water-soluble ethylenically unsaturated monomers, (meth)acrylic acid and salts thereof, (meth)acrylamide, and N,N-dimethyl(meth)acrylamide are preferably used from the standpoint of industrial availability. Moreover, from the standpoint of high water-absorption ability of the resulting water-absorbent resin particles, (meth)acrylic acid and salts thereof are more preferably used. In performing a multistep polymerization including two or more steps, the water-soluble ethylenically unsaturated monomer used in the second and subsequent steps may be the same as or different from the water-soluble ethylenically unsaturated monomer used in the first step. When the water-soluble ethylenically unsaturated monomer is subjected to reversed-phase suspension polymerization, the water-soluble ethylenically unsaturated monomer may be used as an aqueous solution to enhance the efficiency of the dispersion of the monomer in the dispersion medium. The concentration of the water-soluble ethylenically unsaturated monomer in the aqueous solution is not particularly limited, but typically 20% by mass or more to the saturation concentration or less, preferably 25 to 70% by mass, and more preferably 30 to 55% by mass. When the water-soluble ethylenically unsaturated monomer contains acid groups, like (meth)acrylic acid or 2-(meth)acrylamide-2-methylpropane sulfonic acid, the acid groups of the water-soluble ethylenically unsaturated monomer for use may optionally be neutralized with an alkaline neutralizer beforehand. The alkaline neutralizer is not particularly limited, but examples of the neutralizer include alkali metal salts, such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium hydroxide, and potassium carbonate; and ammonia. The alkaline neutralizer for use may be in the form of an aqueous solution to simplify the neutralizing operation. These alkaline neutralizers may be used alone, or in a combination of two or more. The degree of neutralization of the water-soluble ethylenically unsaturated monomer with the alkaline neutralizer is not particularly limited. However, to increase the osmotic pressure of the obtained water-absorbent resin particles and thereby increase the water-absorption ability, while avoiding safety concerns attributed to an excess amount of the alkaline neutralizer, the degree of neutralization relative to all acid groups contained in the water-soluble ethylenically unsaturated monomer is preferably 10 to 100 mol %, and more preferably 30 to 80 mol %. The reversed-phase suspension polymerization of the present invention is preferably performed in the presence of a radical polymerization initiator to suitably shorten the time period required for the polymerization reaction. Examples of radical polymerization initiators for use in the present invention include persulfates, such as potassium persulfate, ammonium persulfate, and sodium persulfate; peroxides, such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, t-butyl peroxyacetate, t-butylperoxy isobutyrate, t-butylperoxy pivalate, and hydrogen peroxide; and azo compounds, such as 2,2′-azobis(2-amidinopropane)dihydrochloride, 2,2′-azobis[2-(N-phenyl amidino)propane]dihydrochloride, 2,2′-azobis[2-(N-allyl amidino)propane]dihydrochloride, 2,2′-azobis{2-[1-(2-hydroxyethyl)-2-imidazoline-2-yl]propane}dihydrochloride, 2,2′-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,2′-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide], and 4,4′-azobis(4-cyanovaleric acid). Of these radical polymerization initiators, potassium persulfate, ammonium persulfate, sodium persulfate, and 2,2′-azobis(2-amidinopropane)dihydrochloride are preferably used from the standpoint of availability and easy handling. These radical polymerization initiators may used alone, or in a combination of two or more. In the use of the radical polymerization initiator, the amount of the initiator is preferably 1 mole or less per 100 moles of the water-soluble ethylenically unsaturated monomer in each polymerization step to prevent rapid polymerization reaction. The lower limit of the amount of the radical polymerization initiator is not particularly limited. For example, the use of 0.005 moles or more of the radical polymerization initiator per 100 moles of the water-soluble ethylenically unsaturated monomer in each polymerization step can suitably shorten the period required for the polymerization reaction. The radical polymerization initiator may be combined with a reducing agent, such as sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, and L-ascorbic acid, to use the initiator as a redox polymerization initiator. To control the water-absorption ability of the water-absorbent resin particles, a chain transfer agent may be added. Examples of chain transfer agents include hypophosphites, thiols, thiol acids, secondary alcohols, and amines. A crosslinking agent may optionally be added to the water-soluble ethylenically unsaturated monomer to perform polymerization. Examples of crosslinking agents to be added to the water-soluble ethylenically unsaturated monomer before a polymerization reaction (internal crosslinking agent) include compounds having two or more polymerizable unsaturated groups, such as unsaturated polyesters obtained by reacting polyols, such as diols and triols including (poly)ethylene glycol (in this specification, “polyethylene glycol” and “ethylene glycol” are collectively referred to as “(poly)ethylene glycol.” The same applies to “(poly)” hereinafter), (poly)propylene glycol, 1,4-butanediol, trimethylolpropane, and (poly)glycerol, with unsaturated acids, such as (meth)acrylic acid, maleic acid, and fumaric acid; bisacrylamides, such as N,N′-methylenebisacrylamide; di- or tri(meth)acrylic acid esters obtained by reacting polyepoxide with (meth)acrylic acid; di(meth)acrylic acid carbamyl esters obtained by reacting polyisocyanates, such as tolylene diisocyanate and hexamethylene diisocyanate, with (meth)acrylic acid hydroxyethyl; allylated starch, allylated cellulose, diallyl phthalate, N,N′,N″-triallyl isocyanurate, and divinylbenzene; and compounds having two or more reactive functional groups, such as polyglycidyl compounds, such as diglycidyl compounds including (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether, and (poly)glycerol diglycidyl ether, and triglycidyl compounds; epihalohydrin compounds, such as epichlorohydrin, epibromohydrin, and α-methyl epichlorohydrin; isocyanate compounds, such as 2,4-tolylene diisocyanate and hexamethylene diisocyanate; and oxetane compounds, such as 3-methyl-3-oxetane methanol, 3-ethyl-3-oxetane methanol, 3-butyl-3-oxetane methanol, 3-methyl-3-oxetane ethanol, 3-ethyl-3-oxetane ethanol, and 3-butyl-3-oxetane ethanol. These internal crosslinking agents may be used alone, or in a combination of two or more. When the internal crosslinking agent is used, the amount of the agent is preferably 0.00001 to 1 mole, and more preferably 0.0001 to 0.5 moles, per 100 moles of the water-soluble ethylenically unsaturated monomer in each polymerization step, in order to sufficiently enhance the water-absorption ability of the resulting water-absorbent resin particles. To adjust the particle size of the resulting water-absorbent resin particles, a thickener may optionally be added to an aqueous solution of the water-soluble ethylenically unsaturated monomer. Examples of thickeners include hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, carboxymethyl cellulose, polyacrylic acid, (partly) neutralized polyacrylic acid, polyethylene glycol, polyacrylamide, polyethyleneimine, dextrin, sodium alginate, polyvinyl alcohol, polyvinyl pyrrolidone, and polyethylene oxide. Typically in reversed-phase suspension polymerization, at the same stirring rotation speed for polymerization, the higher the viscosity of the water-soluble ethylenically unsaturated monomer aqueous solution, the more likely the particle size of the resulting water-absorbent resin particles becomes larger. When the thickener is used, the amount of the agent cannot be uniformly determined because of the variation of the obtained viscosity of the monomer aqueous solution, depending on the type of thickener; however, the amount of the agent is preferably 0.005 to 10 parts by mass, and more preferably 0.01 to 5 parts by mass, per 100 parts by mass of the water-soluble ethylenically unsaturated monomer used in the first-step polymerization, from the standpoint of the particle size adjustment of the resulting water-absorbent resin particles. In the present invention, a hydrocarbon dispersion medium is preferable as a dispersion medium. Examples of hydrocarbon dispersion media include aliphatic hydrocarbons having 6 to 8 carbon atoms, such as n-hexane, n-heptane, 2-methylhexane, 3-methylhexane, 2,3-dimethylpentane, 3-ethylpentane, and n-octane; alicyclic hydrocarbons, such as cyclohexane, methylcyclohexane, cyclopentane, methylcyclopentane, trans-1,2-dimethylcyclopentane, cis-1,3-dimethylcyclopentane, and trans-1,3-dimethylcyclopentane; and aromatic hydrocarbons, such as benzene, toluene, and xylene. These dispersion media may be used alone, or in a combination of two or more. Of these dispersion media, n-hexane, n-heptane, and cyclohexane are preferably used from the standpoint of industrial availability, stable quality, and inexpensive prices. Hydrocarbon dispersion media, such as n-hexane, n-heptane, cyclohexane, and isomers thereof, and mixed hydrocarbons containing at least two members selected from the group consisting of n-hexane, n-heptane, cyclohexane, and isomers thereof are also preferably used. As an example of the mixed dispersion media described above, commercially available Exxsol Heptane (Exxon Mobil Corporation: containing 75 to 85% by mass of hydrocarbons, i.e., heptane and its isomer) may be used, and it will also give preferable results. The amount of the dispersion medium is preferably 100 to 1,500 parts by mass, and more preferably 200 to 1,400 parts by mass, per 100 parts by mass of the water-soluble ethylenically unsaturated monomer used in the first-step polymerization, from the standpoint of easy removal of the polymerization heat and easy control of the polymerization temperature. The phrase “the first-step polymerization” refers to the step in single-step polymerization and the first-step polymerization in multistep polymerization containing two or more steps. The most notable feature of the present invention is that in a method for producing water-absorbent resin particles by subjecting a water-soluble ethylenically unsaturated monomer to reversed-phase suspension polymerization in a dispersion medium (preferably in a hydrocarbon dispersion medium), the reversed-phase suspension polymerization is performed in the presence of an organic acid monoglyceride. The organic acid monoglyceride suitably enhances the dispersion stability of the water-soluble ethylenically unsaturated monomer in the dispersion medium. In the present invention, the organic acid monoglyceride refers to an organic acid ester of monoglyceride (a glycerol fatty acid ester). In other words, the organic acid monoglyceride refers to a compound in which fatty acid (A) is ester-bonded with one of three hydroxyl groups of glycerol, and organic acid (B) is ester-bonded with the remaining hydroxyl groups. The number of organic acid (B) bonded with the remaining hydroxyl groups may be one or two per molecule of glycerol. The organic acid monoglyceride for use may also be a mixture of a compound in which one molecule of organic acid (B) is ester-bonded with one molecule of glycerol, and a compound in which two molecules of organic acid (B) are ester-bonded with one molecule of glycerol. As fatty acid (A), fatty acids having 10 to 18 carbon atoms are preferable. Specific examples include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid. Examples of organic acid (B) include monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids. As long as the group “—COOH” is contained, substituents other than the carboxyl group may also be contained. Examples of containable substituents other than the carboxyl group include hydroxyl group and acetyloxy group. As organic acid (B), carboxylic acid compounds listed above as fatty acid (A) may also be used. As organic acid (B), organic acids having 2 to 8 carbon atoms are preferable. Specific examples include acetic acid, lactic acid, citric acid, succinic acid, and diacetyl tartaric acid. The hydrophilic-lipophilic balance (HLB) of the organic acid monoglyceride is preferably 2 to 17, and more preferably 2 to 10, to allow the organic acid monoglyceride to dissolve in a dispersion medium (preferably a hydrocarbon dispersion medium) and to enhance the dispersion stability of the water-soluble ethylenically unsaturated monomer. The organic acid monoglyceride is not particularly limited as long as it falls within the scope described above. Examples include glyceryl monolaurate acetate, glyceryl monostearate acetate, glyceryl monostearate lactate, glyceryl monostearate succinate, glyceryl monostearate diacetyl tartaric acid ester, glyceryl monostearate citrate, and glyceryl monooleate citrate. Of these, glyceryl monolaurate acetate, glyceryl monostearate acetate, glyceryl monostearate lactate, glyceryl monostearate citrate, and glyceryl monooleate citrate are preferably used from the standpoint of the dispersion stability of the water-soluble ethylenically unsaturated monomer in a dispersion medium. These organic acid monoglycerides may be used alone, or in a combination of two or more. These organic acid monoglycerides can be produced, for example, by esterifying a monoglyceride (a glycerol fatty acid ester) with an organic acid. Commercially available organic acid monoglycerides may also be used unmodified. Examples of commercially available products include Poem G-002 (Riken Vitamin Co., Ltd.); and Sunsoft No. 621B and Sunsoft No. 661AS (Taiyo Kagaku Co., Ltd.). As long as the dispersion stability achieved by the organic acid monoglyceride is not impaired, other dispersion stabilizer(s) may also be used in combination. Examples of dispersion stabilizers for combination use include sucrose fatty acid esters, polyglycerol fatty acid esters, and sorbitan fatty acid esters. In addition, as a dispersion stabilizer, a polymeric dispersion stabilizer may be used in combination with the organic acid monoglyceride. Examples of polymeric dispersion stabilizers for use include maleic anhydride modified polyethylene, maleic anhydride modified polypropylene, and maleic anhydride modified ethylene-propylene copolymers. These polymeric dispersion stabilizers may be used alone, or in a combination of two or more. The amount of the organic acid monoglyceride is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and particularly more preferably 0.5 parts by mass or more, per 100 parts by mass of the water-soluble ethylenically unsaturated monomer in the first-step polymerization from the standpoint of maintaining an excellent dispersion state of the water-soluble ethylenically unsaturated monomer in a dispersion medium. To obtain a dispersion effect that meets the amount of the organic acid monoglyceride used, the amount is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and particularly more preferably 5 parts by mass or less, per 100 parts by mass of the water-soluble ethylenically unsaturated monomer used in the first-step polymerization. For example, about 1.2 parts by mass of the organic acid monoglyceride per 100 parts by mass of the water-soluble ethylenically unsaturated monomer can be used. When the polymeric dispersion stabilizer is used, the amount of the stabilizer is preferably 0.1 to 30 parts by mass, and more preferably 0.3 to 20 parts by mass, per 100 parts by mass of the water-soluble ethylenically unsaturated monomer in the first-step polymerization. The reaction temperature for the polymerization reaction cannot be uniformly determined because of its variation depending on the presence or absence of a radical polymerization initiator and the type of the initiator; however, the reaction temperature is preferably 20 to 110° C., and more preferably 40 to 90° C. from the standpoint that profitability may be improved by allowing prompt progress of a polymerization to reduce a polymerization time, and polymerization heat may be easily removed to perform a smooth reaction. The reaction time is preferably 0.1 hours to 4 hours. The polymerization reaction is preferably performed in an inert gas atmosphere, such as nitrogen or argon, as necessary. In the present invention, when a multistep polymerization including two or more steps is performed, the polymerization reaction in the second and subsequent steps may be performed by further adding the water-soluble ethylenically unsaturated monomer to the water-absorbent resin particles obtained by reversed-phase suspension polymerization. When the water-soluble ethylenically unsaturated monomer is further added, the radical polymerization initiator and/or the internal crosslinking agent described above may also be further added. The amounts of the radical polymerization initiator and the internal crosslinking agent added in the second and subsequent steps are as described above. In the present invention, it is preferable to incorporate a post-crosslinking step of adding a crosslinking agent anytime after polymerization of the water-soluble ethylenically unsaturated monomer to allow for a reaction. Performing a post-crosslinking step after polymerization enhances the water-absorption ability, such as water-retention capacity, thus providing water-absorbent resin particles suitable for absorbent articles, such as disposable diapers. Examples of crosslinking agents for use in a post-crosslinking step (post-crosslinking agents) include compounds having at least two reactive functional groups. Examples of the compound include polyols, such as ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, glycerol, polyoxyethylene glycol, polyoxy propylene glycol, and polyglycerol; polyglycidyl compounds, such as (poly)ethylene glycol diglycidyl ether, (poly)glycerol diglycidyl ether, (poly)glycerol triglycidyl ether, (poly)propylene glycol polyglycidyl ether, and (poly)glycerol polyglycidyl ether; halo-epoxy compounds, such as epichlorohydrin, epibromohydrin, and α-methyl epichlorohydrin; isocyanate compounds, such as 2,4-tolylene diisocyanate, and hexamethylene diisocyanate; oxetane compounds, such as 3-methyl-3-oxetane methanol, 3-ethyl-3-oxetane methanol, 3-butyl-3-oxetane methanol, 3-methyl-3-oxetane ethanol, 3-ethyl-3-oxetane ethanol, and 3-butyl-3-oxetane ethanol; oxazoline compounds, such as 1,2-ethylene bisoxazoline; carbonate compounds, such as ethylene carbonate; and hydroxy alkylamide compounds, such as bis[N,N-di(β-hydroxyethyl)]adipamide. Of these post-crosslinking agents, polyglycidyl compounds, such as (poly)ethylene glycol diglycidyl ether, (poly)glycerol diglycidyl ether, (poly)glycerol triglycidyl ether, (poly)propylene glycol polyglycidyl ether, and (poly)glycerol polyglycidyl ether are preferably used. These post-crosslinking agents may be used alone, or in a combination of two or more. When the post-crosslinking agent is used, the amount of the agent is preferably 0.001 to 1 mole, and more preferably 0.005 to 0.5 moles, based on the total amount of the water-soluble ethylenically unsaturated monomer used for polymerization, which is taken as 100 moles, from the standpoint of the enhancement of the water-absorption ability, such as water-retention capacity, of the resulting water-absorbent resin particles. The timing for adding the post-crosslinking agent is not particularly limited, as long as the agent is added anytime after polymerization. Examples of methods for adding the post-crosslinking agent include a method comprising adding a post-crosslinking agent as it is, a method comprising adding an aqueous solution of the agent, and a method comprising adding a solution of the agent in a hydrophilic organic solvent. Examples of the hydrophilic organic solvent include lower alcohols, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and propylene glycol; ketones, such as acetone, and methyl ethyl ketone; ethers, such as diethyl ether, dioxane, and tetrahydrofuran; amides, such as N,N-dimethyl formamide; and sulfoxides, such as dimethyl sulfoxide. These hydrophilic organic solvents may be used alone or in a combination of two or more, and may also be used as a mixture solvent with water. The method for adding the post-crosslinking agent is not particularly limited. Examples of the addition method include a method comprising adding a post-crosslinking agent (post-crosslinking agent solution) to a water-containing gel obtained by dispersing the water-absorbent resin particles in a dispersion medium; and a method comprising evaporating the dispersion medium and then spraying the post-crosslinking agent (post-crosslinking agent solution) using a spray while stirring powdery water-absorbent resin particles. The post-crosslinking agent may be added, for example, in the presence of preferably 1 to 400 parts by mass of water, more preferably 5 to 200 parts by mass of water, and still more preferably 10 to 100 parts by mass of water, per 100 parts by mass of the water-soluble ethylenically unsaturated monomer. The temperature for the post-crosslinking step is preferably 50 to 250° C., more preferably 60 to 180° C., and still more preferably 70 to 150° C. The time period for the post-crosslinking step cannot be uniformly determined because of the variation depending on the reaction temperature, the type and the amount of the post-crosslinking agent, and the like; however, the time period is typically 1 to 300 minutes, and preferably 5 to 200 minutes. The present invention may optionally comprise, after polymerization, a drying step of externally adding energy such as heat to remove water, the dispersion medium, and the like, by distillation. The drying step may be performed under ordinary pressure, or under reduced pressure, and also under air stream, such as nitrogen, to increase the drying efficiency; these methods may also be combined. When the drying step is performed under ordinary pressure, the drying temperature is preferably 70 to 250° C., more preferably 80 to 180° C., and still more preferably 80 to 140° C. When the drying step is performed under reduced pressure, the drying temperature is preferably 60 to 100° C., and more preferably 70 to 90° C. Additives, such as a lubricant, a deodorizer, and an anti-bacterial agent, may be further added to the water-absorbent resin particles of the present invention, depending on the intended use. The thus-obtained water-absorbent resin particles can be suitably used in absorbent materials and water-absorbent articles using the absorbent materials, because of the excellent water-absorption ability, suitable particle size, and narrow particle size distribution. The water-retention capacity of physiological saline, median particle size, and uniformity degree of particle size distribution of water-absorbent resin particles are measured by the methods described below. The water-retention capacity of physiological saline of the water-absorbent resin particles obtained by the production method of the present invention is preferably 20 g/g or more, more preferably 25 g/g or more, and still more preferably 30 g/g or more from the standpoint of increasing the absorption capacity of the absorbent material used in absorbent articles. The median particle size of the water-absorbent resin particles obtained by the production method of the present invention cannot be uniformly limited because of the variation depending on the intended use; however, the median particle size is, for example, about 10 to 800 μm. When the particles are used, for example, in shin sheet products, such as water-blocking materials for power cable, particles having a small median particle size of about 20 to 200 μm are selected. When the water-absorbent resin particles and hydrophilic fibers are mixed to prepare an absorbent material for use in absorbent articles, such as disposable diapers, particles having a relatively large median particle size of about 200 to 600 μm are selected. The particle size distribution of the water-absorbent resin particles is preferably narrow. Small particles are unsatisfactory in powder flowability and generate dust, whereas particles with an unnecessarily large size may degrade the quality of applied products of the water-absorbent resin particles. For example, in the case of disposable diapers, water-absorbent resin particles with a small particle size are difficult to transfer in the production of absorbent materials, and may pass through a metallic mesh. With particles with a large particle size, on the other hand, the absorbent material may become hard, or give a grainy, unpleasant texture when being compressed. Thus, the uniformity degree of particle size distribution of water-absorbent resin particles, which serves as an index for indicating the narrowness of particle size distribution, is preferably 3.0 or less, more preferably 2.6 or less, and still more preferably 2.4 or less. The water-retention capacity of physiological saline indicates the mass of physiological saline that can be absorbed by water-absorbent resin particles per unit mass (i.e., the index of water absorption capacity of water-absorbent resin particles). Specifically, the water-retention capacity of physiological saline is determined by dispersing water-absorbent resin particles in physiological saline (0.9% by mass sodium chloride aqueous solution), allowing the particles to swell, removing the water that was not absorbed by the water-absorbent resin particles by centrifugation and the like, measuring the mass of the swollen water-absorbent resin particles, and dividing the measured mass by the mass of the water-absorbent resin particles before being swollen. Specifically, the water-retention capacity of physiological saline (g/g) is a value determined by the equation: mass ( g ) of water-absorbent resin particles after swelling/mass ( g ) of water-absorbent resin particles before swelling The median particle size indicates the particle size at 50% point of cumulative distribution obtained by integrating, in order from the larger particle size, the frequency distribution showing what percent of the total particles is present in a predetermined particle size range. Specifically, particles are sorted out using several different JIS standard sieves. Then, the proportion of particles having a particle size larger than the sieve opening is calculated as a percentage of the total mass, and a cumulative mass percentage is determined. The obtained cumulative mass percentages are then plotted on logarithmic probability paper such that each particle size corresponds to the opening size of each sieve to draw an approximate straight line, and the 50% by mass point of cumulative mass percentage on the line is determined as the median particle size. More specifically, the median particle size is calculated, for example, in accordance with the procedure in the Examples described below. The uniformity degree of particle size distribution is calculated by determining the particle size (X1) corresponding to 15.9% by mass (cumulative mass percentage) and the particle size (X2) corresponding to 84.1% by mass (cumulative mass percentage) on the basis of the approximate straight line showing a correlation between the cumulative mass percentage and the particle size obtained in median particle size measurement, and applying the obtained values to the following equation: uniformity degree= X 1 /X 2 The uniformity degree closer to the lower limit 1.0 indicates a narrower particle size distribution. EXAMPLES The following Examples and Comparative Examples describe the present invention in more detail. However, the present invention is not limited to the Examples. Evaluation Method The properties of the water-absorbent resin particles obtained in the Examples and Comparative Examples were measured and evaluated in accordance with the procedures described below. (1) Water-Retention Capacity of Physiological Saline 500 g of a 0.9% by mass sodium chloride aqueous solution (physiological saline) was weighed and placed in a 500-mL beaker, and 2.0 g of water-absorbent resin particles was dispersed in the solution with stirring at 600 r/min so as not to form lumps. The dispersion was allowed to stand for 30 minutes while being stirred so that the water-absorbent resin particles were allowed to sufficiently swell. Thereafter, the swollen dispersion was poured into a cotton bag (cotton broadcloth No. 60, 100 mm in length×200 mm in width), and the top of the cotton bag was tied with a rubber band, followed by dehydration for 1 minute with a dehydrator (Kokusan Co., Ltd., Model No: H-122) with the centrifugal force set at 167G, thereby measuring the mass Wa (g) of the cotton bag containing the dehydrated swollen gel. The same procedure was repeated without using water-absorbent resin particles, and the empty mass Wb (g) of the cotton bag upon swelling was measured. The water-retention capacity of physiological saline of the water-absorbent resin particles was determined from the following equation: water-retention capacity of physiological saline ( g/g )=[ Wa−Wb ]( g )/mass of water-absorbent resin particles ( g ) (2) Median Particle Size About 50 g of water-absorbent resin particles was allowed to pass through a JIS standard sieve with opening of 250 μm. When 50% by mass or more of the particles were passed through the sieve, the combination of sieves (A) was used to measure the median particle size; when less than 50% by mass of the particles were passed through the sieve, the combination of sieves (B) was used to measure the median particle size. (A) JIS standard sieves were combined in the following order: from the top, a sieve with opening of 500 μm, a sieve with opening of 250 μm, a sieve with opening of 180 μm, a sieve with opening of 150 μm, a sieve with opening of 106 μm, a sieve with opening of 75 μm, a sieve with opening of 45 μm, and a receiving tray. (B) JIS standard sieves were combined in the following order: from the top, a sieve with opening of 850 μm, a sieve with opening of 600 μm, a sieve with opening of 500 μm, a sieve with opening of 425 μm, a sieve with opening of 300 μm, a sieve with opening of 250 μm, a sieve with opening of 150 μm, and a receiving tray. About 50 g of the water-absorbent resin particles was placed in the top sieve of the combination sieves, and shaken with a rotating-tapping shaker for 10 minutes for classification. After classification, the mass of the water-absorbent resin particles remained in each sieve was calculated as mass percentage of the entire water-absorbent resin particles, and integrated in order from the large particle size. Subsequently, the correlation between the opening sizes of the sieves and the cumulative values calculated as mass percentage of the water-absorbent resin particles remaining in the sieves were dotted on logarithmic probability paper. The dots on the paper were connected to form a straight line, and the particle size at which the cumulative mass percentage is 50% by mass was determined to be the median particle size. (3) Uniformity Degree of Particle Size Distribution In the section (2) Median Particle Size, particle size (X1) corresponding to the cumulative mass percentage of 15.9% by mass and particle size (X2) corresponding to the cumulative mass percentage of 84.1% by mass were calculated, and the uniformity degree was determined from the following equation: uniformity degree= X 1/ X 2 The uniformity degree closer to 1.0 indicates a narrower particle size distribution. Example 1 A 2-L round-bottom cylindrical separable flask with an inner diameter of 100 mm, equipped with a reflux condenser, a dropping funnel, a nitrogen gas inlet tube, a stirrer, and stirring blades (two sets of four inclined paddle blades with a blade diameter of 50 mm) was used in this Example. 321 g (472 ml) of n-heptane was placed in this flask, and then 0.92 g of glyceryl monolaurate acetate with an HLB of 2.0 (Riken Vitamin Co., Ltd., Poem G-002) was added thereto as a dispersion stabilizer. The mixture was heated to 80° C. with stirring to dissolve the dispersion stabilizer, and then cooled to 65° C. 92 g (1.03 moles) of an 80.5% by mass acrylic acid aqueous solution and 51.2 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 102.9 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.27 g of hydroxyethyl cellulose (Sumitomo Seika Chemicals Co., Ltd., AW-15F) as a thickener, 0.11 g (0.41 mmoles) of potassium persulfate as a radical polymerization initiator, and 9.2 mg (0.05 mmoles) of ethylene glycol diglycidyl ether as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution. The monomer aqueous solution was added to the separable flask, and maintained at 45° C. for 30 minutes with the stirrer rotation set at 700 r/min, while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization was allowed to proceed for 60 minutes. After polymerization, the rotation of the stirrer was changed to 1,000 r/min, the flask was immersed in an oil bath at 125° C. to increase the temperature, and 125.7 g of water was removed to the outside of the system under reflux of n-heptane by azeotropic distillation of water and n-heptane. Subsequently, 3.68 g of a 2% by mass aqueous solution of ethylene glycol diglycidyl ether was added thereto as a post-crosslinking agent, and water and n-heptane were continuously removed by distillation, followed by drying, thereby obtaining 97.1 g of spherical water-absorbent resin particles. The physical properties of the water-absorbent resin particles were evaluated in accordance with the procedures described above. Table 1 shows the results. Example 2 A 2-L round-bottom cylindrical separable flask with an inner diameter of 100 mm, equipped with a reflux condenser, a dropping funnel, a nitrogen gas inlet tube, a stirrer, and stirring blades (two sets of four inclined paddle blades with a blade diameter of 50 mm) was used in this Example. 321 g (472 ml) of n-heptane was placed in this flask, and then 0.92 g of glyceryl monostearate citrate with an HLB of 9.5 (Taiyo Kagaku Co., Ltd., Sunsoft No. 621B) as a dispersion stabilizer, and 0.92 g of a maleic anhydride modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., Hi-WAX 1105A) as a polymeric dispersion stabilizer were added thereto. The mixture was heated to 80° C. with stirring to dissolve the dispersion stabilizer, and then cooled to 65° C. 92 g (1.03 moles) of an 80.5% by mass acrylic acid aqueous solution and 51.2 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 102.9 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.27 g of hydroxyethyl cellulose (Sumitomo Seika Chemicals Co., Ltd., AW-15F) as a thickener, 0.11 g (0.41 mmoles) of potassium persulfate as a radical polymerization initiator, and 9.2 mg (0.05 mmoles) of ethylene glycol diglycidyl ether as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution. The monomer aqueous solution was added to the separable flask, and maintained at 45° C. for 30 minutes with the stirrer rotation set at 700 r/min, while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization was allowed to proceed for 60 minutes. After polymerization, the rotation of the stirrer was changed to 1,000 r/min, the flask was immersed in an oil bath at 125° C. to increase the temperature, and 125.7 g of water was removed to the outside of the system under reflux of n-heptane by azeotropic distillation of water and n-heptane. Subsequently, 3.68 g of a 2% by mass aqueous solution of ethylene glycol diglycidyl ether was added thereto as a post-crosslinking agent, and water and n-heptane were continuously removed by distillation, followed by drying, thereby obtaining 97.5 g of spherical water-absorbent resin particles. The physical properties of the water-absorbent resin particles were evaluated in accordance with the procedures described above. Table 1 shows the results. Example 3 A 2-L round-bottom cylindrical separable flask with an inner diameter of 100 mm, equipped with a reflux condenser, a dropping funnel, a nitrogen gas inlet tube, a stirrer, and stirring blades (two sets of four inclined paddle blades with a blade diameter of 50 mm) was used in this Example. 321 g (472 ml) of n-heptane was placed in this flask, and then 0.92 g of glyceryl monolaurate acetate with an HLB of 2.0 (Riken Vitamin Co., Ltd., Poem G-002) as a dispersion stabilizer, and 0.92 g of a maleic anhydride modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., Hi-WAX 1105A) as a polymeric dispersion stabilizer were added thereto. The mixture was heated to 80° C. with stirring to dissolve the dispersion stabilizer, and then cooled to 65° C. 92 g (1.03 moles) of an 80.5% by mass acrylic acid aqueous solution and 51.2 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 102.9 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.27 g of hydroxyethyl cellulose (Sumitomo Seika Chemicals Co., Ltd., AW-15F) as a thickener, 0.11 g (0.41 mmoles) of potassium persulfate as a radical polymerization initiator, and 9.2 mg (0.05 mmoles) of ethylene glycol diglycidyl ether as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution of the first step. The monomer aqueous solution of the first step was added to the separable flask, and maintained at 45° C. for 30 minutes with the stirrer rotation set at 700 r/min, while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization of the first step was allowed to proceed for 60 minutes. After polymerization, a slurry was obtained. 128.2 g (1.43 moles) of an 80.5% by mass acrylic acid aqueous solution and 30.5 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 143.3 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.15 g (0.56 mmoles) of potassium persulfate as a radical polymerization initiator, and 12.8 mg (0.07 mmoles) of ethylene glycol diglycidyl ether as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution of the second step. After the rotation of the stirrer was changed to 1,000 r/min, the monomer aqueous solution of the second step was added to the separable flask, and maintained at 20° C. for 30 minutes while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization of the second step was allowed to proceed for 30 minutes. After polymerization of the second step, the flask was immersed in an oil bath at 125° C. to increase the temperature, and 258.5 g of water was removed to the outside of the system under reflux of n-heptane by azeotropic distillation of water and n-heptane. Subsequently, 3.96 g of a 2% by mass aqueous solution of ethylene glycol diglycidyl ether was added thereto as a post-crosslinking agent, and water and n-heptane were continuously removed by distillation, followed by drying, thereby obtaining 241.9 g of water-absorbent resin particles in the form of agglomerated spherical particles. The physical properties of the water-absorbent resin particles were evaluated in accordance with the procedures described above. Table 1 shows the results. Example 4 A 2-L round-bottom cylindrical separable flask with an inner diameter of 100 mm, equipped with a reflux condenser, a dropping funnel, a nitrogen gas inlet tube, a stirrer, and stirring blades (two sets of four inclined paddle blades with a blade diameter of 50 mm) was used in this Example. 321 g (472 ml) of n-heptane was placed in this flask, and then 0.92 g of glyceryl monostearate lactate with an HLB of 7.5 (Taiyo Kagaku Co., Ltd., Sunsoft No. 661AS) as a dispersion stabilizer and 0.92 g of a maleic anhydride modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., Hi-WAX 1105A) as a polymeric dispersion stabilizer were added thereto. The mixture was heated to 80° C. with stirring to dissolve the dispersion stabilizer, and then cooled to 65° C. 92 g (1.03 moles) of an 80.5% by mass acrylic acid aqueous solution and 51.2 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 102.9 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.27 g of hydroxyethyl cellulose (Sumitomo Seika Chemicals Co., Ltd., AW-15F) as a thickener, 0.11 g (0.41 mmoles) of potassium persulfate as a radical polymerization initiator, and 9.2 mg (0.05 mmoles) of ethylene glycol diglycidyl ether as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution of the first step. The monomer aqueous solution of the first step was added to the separable flask, and maintained at 45° C. for 30 minutes with the stirrer rotation set at 700 rpm, while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization of the first step was allowed to proceed for 60 minutes. After polymerization, a slurry was obtained. 128.2 g (1.43 moles) of an 80.5% by mass acrylic acid aqueous solution and 30.5 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 143.3 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.15 g (0.56 mmoles) of potassium persulfate as a radical polymerization initiator, and 12.8 mg (0.07 mmoles) of ethylene glycol diglycidyl ether as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution of the second step. After the rotation of the stirrer was changed to 1,000 r/min, the monomer aqueous solution of the second step was added to the separable flask, and maintained at 20° C. for 30 minutes while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization of the second step was allowed to proceed for 30 minutes. After polymerization of the second step, the flask was immersed in an oil bath at 125° C. to increase the temperature, and 258.5 g of water was removed to the outside of the system under reflux of n-heptane by azeotropic distillation of water and n-heptane. Subsequently, 3.96 g of a 2% by mass aqueous solution of ethylene glycol diglycidyl ether was added thereto as a post-crosslinking agent, and water and n-heptane were continuously removed by distillation, followed by drying, thereby obtaining 242.1 g of water-absorbent resin particles in the form of agglomerated spherical particles. The physical properties of the water-absorbent resin particles were evaluated in accordance with the procedures described above. Table 1 shows the results. Comparative Example 1 A 2-L round-bottom cylindrical separable flask with an inner diameter of 100 mm, equipped with a reflux condenser, a dropping funnel, a nitrogen gas inlet tube, a stirrer, and stirring blades (two sets of four inclined paddle blades with a blade diameter of 50 mm) was used in this Example. 321 g (472 ml) of n-heptane was placed in this flask, and then 0.92 g of tetra glycerin stearic acid ester with an HLB of 4 (Mitsubishi-Kagaku Foods Corporation, Ryoto Polygly TS-4) as a dispersion stabilizer and 0.92 g of a maleic anhydride modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., Hi-WAX 1105A) as a polymeric dispersion stabilizer were added thereto. The mixture was heated to 80° C. with stirring to dissolve the dispersion stabilizer, and then cooled to 55° C. 92 g (1.03 moles) of an 80.5% by mass acrylic acid aqueous solution and 51.2 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 102.9 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.27 g of hydroxyethyl cellulose (Sumitomo Seika Chemicals Co., Ltd., AW-15F) as a thickener, 0.11 g (0.41 mmoles) of potassium persulfate as a radical polymerization initiator, and 9.2 mg (0.05 mmoles) of ethylene glycol diglycidyl ether as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution. The monomer aqueous solution was added to the separable flask, and maintained at 35° C. for 30 minutes with the stirrer rotation set at 700 r/min, while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization was allowed to proceed for 60 minutes. After polymerization, the rotation of the stirrer was changed to 1,000 r/min. The flask was immersed in an oil bath at 125° C. to increase the temperature, and 125.7 g of water was removed to the outside of the system under reflux of n-heptane by azeotropic distillation of water and n-heptane. Subsequently, 3.68 g of a 2% by mass aqueous solution of ethylene glycol diglycidyl ether was added thereto as a post-crosslinking agent, and water and n-heptane were continuously removed by distillation, followed by drying, thereby obtaining 97.0 g of spherical water-absorbent resin particles. The physical properties of the water-absorbent resin particles were evaluated in accordance with the procedures described above. Table 1 shows the results. Comparative Example 2 A 2-L round-bottom cylindrical separable flask with an inner diameter of 100 mm, equipped with a reflux condenser, a dropping funnel, a nitrogen gas inlet tube, a stirrer, and stirring blades (two sets of four inclined paddle blades with a blade diameter of 50 mm) was used in this Example. 321 g (472 ml) of n-heptane was placed in this flask, and then 0.92 g of tetra glycerin stearic acid ester with an HLB of 4 (Mitsubishi-Kagaku Foods Corporation, Ryoto Polygly TS-4) as a dispersion stabilizer and 0.92 g of a maleic anhydride modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., Hi-WAX 1105A) as a polymeric dispersion stabilizer were added thereto. The mixture was heated to 80° C. with stirring to dissolve the dispersion stabilizer, and then cooled to 55° C. 92 g (1.03 moles) of an 80.5% by mass acrylic acid aqueous solution and 51.2 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 102.9 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.27 g of hydroxyethyl cellulose (Sumitomo Seika Chemicals Co., Ltd., AW-15F) as a thickener, 0.11 g (0.41 mmoles) of potassium persulfate as a radical polymerization initiator, and 9.2 mg (0.05 mmoles) of ethylene glycol diglycidyl ether as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution of the first step. The monomer aqueous solution of the first step was added to the separable flask, and maintained at 35° C. for 30 minutes with the stirrer rotation set at 450 r/min, while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization of the first step was allowed to proceed for 60 minutes. After polymerization, a slurry was obtained. 128.2 g (1.43 moles) of an 80.5% by mass acrylic acid aqueous solution and 30.5 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 143.3 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.15 g (0.56 mmoles) of potassium persulfate as a radical polymerization initiator and 12.8 mg (0.07 mmoles) of ethylene glycol diglycidyl ether as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution of the second step. After the rotation of the stirrer was changed to 1,000 r/min, the monomer aqueous solution of the second step was added to the separable flask, and maintained at 25° C. for 30 minutes while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization of the second step was allowed to proceed for 30 minutes. After polymerization of the second step, the flask was immersed in an oil bath at 125° C. to increase the temperature, and 267.8 g of water was removed to the outside of the system under reflux of n-heptane by azeotropic distillation of water and n-heptane. Subsequently, 3.96 g of a 2% by mass aqueous solution of ethylene glycol diglycidyl ether was added thereto as a post-crosslinking agent, and water and n-heptane were continuously removed by distillation, followed by drying, thereby obtaining 242.5 g of water-absorbent resin particles in the form of agglomerated spherical particles. The physical properties of the water-absorbent resin particles were evaluated in accordance with the procedures described above. Table 1 shows the results. Comparative Example 3 A 2-L round-bottom cylindrical separable flask with an inner diameter of 100 mm, equipped with a reflux condenser, a dropping funnel, a nitrogen gas inlet tube, a stirrer, and stirring blades (two sets of four inclined paddle blades with a blade diameter of 50 mm) was used in this Example. 378 g (472 ml) of cyclohexane was placed in this flask, and then 0.92 g of sorbitan monostearate with an HLB of 4.7 (Kao Corporation, Rheodol SP-10V) as a dispersion stabilizer and 0.92 g of a maleic anhydride modified ethylene-propylene copolymer (Mitsui Chemicals, Inc., Hi-WAX 1105A) as a polymeric dispersion stabilizer were added thereto. The mixture was heated to 80° C. with stirring to dissolve the dispersion stabilizer, and then cooled to 55° C. 92 g (1.03 moles) of an 80.5% by mass acrylic acid aqueous solution and 51.2 g of ion-exchanged water were placed in a 500-mL Erlenmeyer flask, and 102.9 g of a 30% by mass sodium hydroxide aqueous solution was added dropwise thereto with external cooling to thereby neutralize 75 mol % of the acid groups. Thereafter, 0.11 g (0.41 mmoles) of potassium persulfate as a radical polymerization initiator, and 2.3 mg (0.01 mmoles) of N,N′-methylene bisacrylamide as an internal crosslinking agent were added thereto and dissolved, thereby preparing a monomer aqueous solution. The monomer aqueous solution was added to the separable flask, and maintained at 35° C. for 30 minutes with the stirrer rotation set at 250 r/min, while the atmosphere of the system was being replaced with nitrogen. Subsequently, the flask was immersed in a water bath at 70° C. to increase the temperature, and polymerization was allowed to proceed for 60 minutes. After polymerization, the rotation of the stirrer was changed to 1,000 r/min. The flask was immersed in an oil bath at 125° C. to increase the temperature, and 125.7 g of water was removed to the outside of the system under reflux of cyclohexane by azeotropic distillation of water and cyclohexane. Subsequently, 3.68 g of a 2% by mass aqueous solution of ethylene glycol diglycidyl ether was added thereto as a post-crosslinking agent, and water and cyclohexane were continuously removed by distillation, followed by drying, thereby obtaining 70.3 g of water-absorbent resin particles in the form of partially agglomerated spherical particles. The physical properties of the water-absorbent resin particles were evaluated in accordance with the procedures described above. Table 1 shows the results. TABLE 1 Uniformity Water- degree of retention Median Particle capacity of Dispersion Particle Size physiological stabilizer Size (μm) Distribution saline (g/g) Example 1 Glyceryl 84 2.2 39 Monolaurate Acetate Example 2 Glyceryl 66 2.0 36 Monostearate Citrate Example 3 Glyceryl 380 1.7 36 Monolaurate Acetate Example 4 Glyceryl 360 1.9 35 Monostearate Lactate Comparative Tetra 57 3.3 35 Example 1 Glycerin Stearic Acid Ester Comparative Tetra 390 3.8 37 Example 2 Glycerin Stearic Acid Ester Comparative Sorbitan 220 3.5 33 Example 3 Monostearate The results shown in Table 1 reveal that the water-absorbent resin particles obtained in each of the Examples have suitable water-retention capacity (water absorption capacity), suitable particle size, and narrow particle size distribution. INDUSTRIAL APPLICABILITY The method according to the present invention can provide water-absorbent resin particles that exhibit an excellent water-absorption ability with a suitable particle size and narrow particle size distribution, and that can suitably be used in absorbent articles, such as sanitary napkins, incontinence pads, and disposable diapers.

Provided is a method for producing water-absorbent resin particles suitable for use in absorbent article and the like, the water-absorbent resin particles having better water-absorbent performance, a suitable particle size, and a narrow particle-size distribution. A method for producing water-absorbent resin particles by reversed-phase suspension polymerization of a water-soluble ethylenic unsaturated monomer in a carrier fluid, wherein the method for producing water-absorbent resin particles comprises conducting the reversed-phase suspension polymerization reaction in the presence of an organic acid monoglyceride.

This is a Continuation Application and claims priority to U.S. patent application Ser. No. 11/562,621 filed Nov. 22, 2006, now abandoned. BACKGROUND OF THE INVENTION This invention relates generally to a carded product known as coil and more particularly to cotton, rayon, or polyester coil which has been vacuum packaged. Coil is a non-woven fiber product comprising “sliver” packaged in helical loops. Coil has many uses in various fields, examples of which are pharmaceutical packaging and cosmetology. Coil is a bulky, low-density material which is typically packed into plastic-lined cartons by feeding cotton sliver, which is a continuous, non-twisted strand of loosely assembled fibers, from a production machine into the carton. This is inefficient as a large package volume is required for a commercially practical quantity of material. Furthermore, in some instances the coil as produced does not have the absorbency capacity desired, which requires an excessive amount of the product to be used to obtain the desired absorbency. BRIEF SUMMARY OF THE INVENTION Accordingly, it is an object of the invention to provided a method of packing coil more compactly in a container. It is another object of the invention to provide coil with increased absorbency. These and other objects are met by the present invention, which in one aspect provides a method of packaging textile coil, including: providing a strand of loosely assembled textile fibers; feeding the strand into a collapsible container; compressing the container so as to cause the container to collapse and compress the strand to a preselected degree; and sealing the container to maintain the strand in a compressed state. According to another aspect of the invention, the container comprises a substantially impermeable bag. According to another aspect of the invention, the method further includes placing the container in a relatively rigid outer carton after the step of sealing. According to another aspect of the invention, the strand comprises cotton sliver. According to another aspect of the invention, the strand is compressed by at least about 25% of its original volume. According to another aspect of the invention, the strand is compressed by at least about 50% of its original volume. According to another aspect of the invention, the step of compressing is carried out by connecting a vacuum source to the container to remove air therefrom. According to another aspect of the invention, a cotton coil includes cotton sliver which is compressed at least about 25% by volume from its free state. According to another aspect of the invention, a cotton coil includes cotton sliver which is compressed by at least about 50% of its original volume. According to another aspect of the invention, a method of protecting a subject's skin during a hair treatment includes: providing textile coil including a strand of loosely assembled textile fibers which has been compressed to a predetermined degree from its original volume; placing the textile coil around a subject's head so as to form a barrier against fluid leakage; and applying a first fluid to subject's head above the textile coil, whereby the first fluid is prevented from contacting the subjects skin below the textile coil. According to another aspect of the invention, the method further includes applying a second fluid to subject's head above the textile coil, whereby the second fluid is prevented from contacting the subject's skin below the textile coil; and removing the textile coil from the subject's head. According to another aspect of the invention, the first fluid is a permanent wave hair styling solution, and the second fluid is a neutralizing solution. BRIEF DESCRIPTION OF THE DRAWINGS The subject matter that is regarded as the invention may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which: FIG. 1 is a schematic view of a vacuum packaging apparatus constructed in accordance with the present invention; FIG. 2 is a side view of cotton sliver being loaded into a container; FIG. 3 is a side view of the container of FIG. 2 during a vacuum packing process; and FIG. 4 is a side view of the container of FIG. 3 after the vacuum packing process is complete. DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings wherein identical reference numerals denote the same elements throughout the various views, FIG. 1 illustrates an exemplary vacuum packing apparatus 10 . The packing apparatus 10 includes a vacuum manifold 12 connected to a vacuum source 14 , and a plurality of “drops” or vertically-hanging vacuum hoses 16 . In the illustrated example the vacuum source 14 comprises a vacuum pump 18 of a known type. Each vacuum hose 16 has an upper end 22 connected to the vacuum manifold 12 and a lower end 24 having a control valve 26 and a nozzle 28 attached thereto. The packing apparatus 10 may be placed in close proximity to an area where containers 30 are loaded with cotton coil. An example of the vacuum packing process is as follows. First, a container 30 such as a cardboard carton is provided with a substantially airtight liner 32 , such as the illustrated polyethylene bag, having a top 34 which defines an opening 36 . Any kind of package which is capable of collapsing around its contents as a vacuum is applied thereto may be used in place of the liner 32 . The lined container 30 is loaded with coil 38 in a known manner (see FIG. 2 ). The term “coil” is used here in its conventional sense meaning the elongated packaged form of sliver, which is a continuous, non-twisted strand of loosely assembled fibers. Normally, coil 38 is made from materials such as cotton sliver, polyester, or rayon, but other types of fibers could be used as well. The base of the container 30 may be lifted upwards using the illustrated pneumatic cylinder 33 or other appropriate means, while the top of the liner 32 is restrained, to force the majority of the air from the liner 32 and compress the coil 38 . This initial compression could also be carried using other types of mechanical devices to compress the liner 32 . The nozzle 28 of one of the vacuum hoses 16 is then inserted into the liner 32 , and the top 34 of the liner 32 is gathered around the nozzle 28 , as shown in FIG. 3 . The control valve 26 is then opened while the top 34 of the liner 32 is held tight around the nozzle 28 . The reduced pressure in the vacuum hose 16 evacuates the air from the liner 32 and causes atmospheric pressure to compress the liner 32 and the coil 38 . The amount of compression is selected by varying the amount of coil 38 , the container size, the applied vacuum pressure and time, etc. Once the liner 32 has been compressed to the desired degree, the nozzle 28 is quickly removed and the top 34 of the liner 32 is twisted to prevent air from re-entering the liner 32 . A wire tie 40 or other suitable closure is applied to the liner top 34 , as shown in FIG. 4 . It is also possible to provide a liner (not shown) having a self-sealing port or other means for allowing the vacuum to be applied without requiring additional steps to seal the line. The flaps 31 of the container 30 may then be closed and sealed, for example with tape, adhesives, or staples. When the liner 32 is opened, the coil 38 expands to its original size. It is noted that the liner 32 could also be compressed by mechanical means, for example using a roller or press (not shown). EXAMPLE 1 Cotton coil of various yard weights was vacuum packaged into containers as described above. Various amounts of the coil were packaged into different size containers. Each combination of quantity and container size corresponded to a different prior art product. In each instance, a given quantity of cotton coil was able to be packaged into a smaller container by using the process described above. Exemplary results of the vacuum packaging are listed in the following tables 1 and 2: TABLE 1 Prior Art Length of Com- Container New Container Product, m pression Example Volume, I (in. 3 ) Volume, I (in. 3 ) (ft.) (%) 1 27.4 (1669.9) 20.7 (1260.8) 329.2 (1080) 24.5 2 27.7 (1691.9) 20.7 (1260.8) 402.3 (1320) 25.5 3 27.7 (1691.9) 20.7 (1260.8) 387.1 (1270) 25.5 4 27.7 (1691.9) 20.7 (1260.8) 307.8 (1010) 25.5 5 27.7 (1691.9) 20.7 (1260.8) 420.6 (1380) 25.5 6 27.4 (1669.9) 20.7 (1260.8) 310.9 (1020) 24.5 TABLE 2 Prior Art Net Weight Com- Container New Container of Product, pression Example Volume, I (in. 3 ) Volume, I (in. 3 ) Kg (lbs.) (%) 7 162.8 (9937.1)   102.6 (6261.8) 9.8 (22) 37.0 8 204.7 (12,492.1)   129 (7871.8) 9.8 (22) 37.0 As can be seen from Tables 1 and 2, vacuum packaging according to the present invention reduced container volume at least about 25% for the same quantity of product. In another example, cotton coil was vacuum packaged into a fixed size container using the method described above. The results of the vacuum packaging are listed in the following table 3: TABLE 3 Container Prior Art Weight New Weight Com- Volume, I of Product, of Product, pression Example (in. 3 ) Kg (lbs.) Kg (lbs.) (%) 9 159.7 (9745.2) 5.4 (12.0) 10.9 (24.0) 50.0 As can be seen from Table 3, vacuum packaging according to the present invention enabled a greater quantity of cotton coil to be packed into the same size container as the prior art product, with an effective compression of about 50%. Thus, the present vacuum packing method, by increasing packing density, has the flexibility to package a given quantity of material in a smaller package, or to increase the quantity of product in a given container volume. This saves packaging, transportation, and warehousing costs. EXAMPLE 2 A comparative test was performed between prior art cotton coil and cotton coil produced according to the present invention, in a cosmetological application. For each trial, a control test was performed. Approximately two wraps of prior art cotton coil were placed around the head of a subject, following the subject's hairline. A suitable quantity of a known chemical solution used for permanent wave hair styling, known as “perm solution”, was applied to the hair. Perm solution is irritating and harmful to skin and thus it is desirable that it touches only the subject's hair and scalp. On average, approximately 27 ml (two tablespoons) of the perm solution dripped past the cotton coil onto the forehead of the subject. After the perm solution remained for the required period of time, the original cotton coil was removed and replaced with approximately two more wraps of prior art cotton coil around the head. A suitable quantity of a known neutralizing solution was then applied to the head. Again, on average about 27 ml (two tablespoons) of the neutralizing solution dripped passed the cotton coil onto the forehead of the subject. Trials were then performed using cotton coil made according to the present invention. For each trial, approximately one full wrap of cotton coil packaged according to the present invention was placed around the head of a subject, following the hairline. The same quantity as was used in the control test of a known chemical solution used for permanent wave hair styling, known as “perm solution”, was applied to the hair. None of the perm solution dripped past the cotton coil onto the forehead of the subject. After the perm solution remained for the required period of time, the cotton coil was found to be dry and in good condition, and therefore could be reused. The same quantity as was used in the control test of a known neutralizing solution was then applied to the head, with the original wrap of cotton coil in place. Again, none of the neutralizing solution dripped passed the cotton coil onto the forehead of the subject. Over 200 trials were performed for the comparative tests described above. Each trial included both a control trial and an inventive trial as described above. The above-noted results were found consistently in each trial. Thus, the cotton coil made according the present invention requires approximately one-quarter of the material required for prior art cotton coil in a beauty application, and lasts approximately twice as long as the prior art coil in the same application. The foregoing has described a vacuum-packed cotton coil and a method for producing the coil. While specific embodiments of the present invention have been described, it will be apparent to those skilled in the art that various modifications thereto can be made without departing from the spirit and scope of the invention. Accordingly, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation.

A method of compressing a cotton strand including the steps of providing an uncompressed strand having an original volume, providing a container adapted to collapse about the strand, feeding the strand into the container, compressing the container to remove a first quantity of air, applying a vacuum to the container to remove a second quantity of air, and sealing the container, wherein the strand is compressed by at least about 25% from its original volume.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates, generally, to methods for cleaning animal carcasses. More particularly, it relates to apparatus and methods for cleaning the neck area of an animal carcass. 2. Description of the Prior Art The federal Food and Drug Administration (FDA) banned the use of brushes in animal carcass cleaning plants for many years because the brushes could become contaminated by one product and therefore other products moving through a cleaning station could become cross-contaminated. The present inventors discovered that the original contamination was possible because multiple bristles, each of which has a substantially circular transverse cross-section, were collectively bundled for mounting in circular blind bores formed in brush heads, enabling bacteria to thrive in the interstitial spaces between the bristles. The present inventors solved the contamination problem by reducing the size of each blind bore and mounting a single bristle in each blind bore, thereby eliminating the interstitial spaces and eliminating the bacterial breeding ground. The FDA then lifted the ban and rotating brushes are now allowed to be used in carcass cleaning procedures. During the ban, carcass cleaning companies relied on oscillating high pressure water jets to perform the cleaning. With the advent of the bacteria-free brushes, most of these companies simply added the new, improved brushes to their cleaning stations without giving much thought as to the proper placement of the brushes, the optimal orientation of the brushes, the length of the individual bristles that collectively form a brush, how the water spray pattern should be adjusted to work with brushes, and so on. Cleaning the neck area of a carcass is problematic. The known methods include spraying the neck area with high pressure water, usually with nozzles that oscillate back and forth. Attempts have been made to improve the cleaning action of the water by increasing its pressure. However, the extra pressure can inhibit the oscillation of the nozzles so what is gained in pressure is lost in coverage. Cleaning with water alone, or brushes alone, however, does not guarantee a clean product. The placement of the brushes, their direction of rotation, the length of their bristles, how the brushes are used in conjunction with spray nozzles, and so on cooperate to produce a clean product. Thus there is a need for a neck cleaning method and apparatus that uses both brushes and water sprays in an optimal way. More particularly, there is a need for methods that teach an optimal placement and orientation of brushes and water sprays relative to one another. There is a need as well for an apparatus that incorporates brushes having bristles that perform more effectively than conventional bristles. However, in view of the prior art taken as a whole at the time the present invention was made, it was not obvious to those of ordinary skill how the identified needs could be fulfilled. SUMMARY OF THE INVENTION The long-standing but heretofore unfulfilled need for an improved neck cleaning method and apparatus is now met by a new, useful, and non-obvious invention. The inventive structure in its basic form is a novel assembly of rotatably-mounted brushes and fluid headers having nozzles along their respective extents for cleaning the neck area of a carcass. The novel assembly of brushes and fluid headers is housed in an elongate, straight structure having an entrance end and an exit end. The brushes are arranged into pairs of brushes and that are transversely spaced apart from one another by a distance sufficient to receive a split carcass therebetween. The first pair of brushes includes two transversely spaced apart brushes that are upwardly inclined and rotate about an axis of rotation that is inclined at a predetermined angle, preferably about forty-five degrees (45°), relative to horizontal. The second pair of brushes is actually a group of four (4) brushes, including a first, leading pair of transversely spaced apart brushes that rotate about a vertical axis and a second, trailing pair of transversely spaced apart brushes that rotate about a vertical axis. The third pair of brushes includes two transversely spaced apart brushes that are downwardly inclined and rotate about an axis of rotation that is inclined at a predetermined angle, preferably about forty-five degrees (45°), relative to horizontal. The pairs of upwardly inclined, vertical, and downwardly inclined brushes are in longitudinal alignment with one another, i.e., the first brush in each pair of brushes is in longitudinal alignment with the first brush of the other pairs and the second brush in each pair of brushes is in longitudinal alignment with the second brush of each other pair. The carcass being cleaned is suspended on an overhead conveyor that transports the carcass into the assembly of brushes at the entrance end, carries it the extent of the housing where it is brushed and sprayed, and carries it out of the exit end of the housing for further treatment. The path of travel of the carcass is coincident with a longitudinal axis of symmetry of the housing. There are two (2) elongate fluid headers associated with each inclined brush and one (1) elongate fluid header associated with each vertical brush. A plurality of water or other liquid fluid-emitting nozzles is formed along the extent of each fluid header. For each inclined brush, a first fluid header is mounted parallel to the axis of rotation of the brush and its nozzles are aimed toward the carcass, just barely missing the radially outermost end of the bristles or appendages. The water therefore impacts against the neck and flows downwardly over the neck under the influence of gravity and under the action of the brushes. A second fluid header is also mounted parallel to the axis of rotation of the brush and is positioned in the same vertical plane as the first fluid header, but the second fluid header is positioned radially closer to the brush. Its nozzles are aimed radially inwardly of the respective distal ends of the bristles or appendages so that the water emitted by the nozzles flows from radially inwardly of the radially outermost end of the bristles towards the radially outermost ends thereof. The nozzles in the lower fluid header are aimed at the brushes as they complete their downward rotation so that the water from the lower fluid header is dedicated to brush cleaning. The neck area is the lower forty inches (40″) or so of the carcass. The neck area is first brushed by the first pair of transversely spaced apart brushes that is upwardly inclined at about a forty five degree (45°) angle. These upwardly inclined brushes are positioned near the entrance end of the assembly of brushes. The leading and trailing pair of vertical brushes follows the upwardly inclined brushes and provides a horizontal attack angle on the most critical area of the neck. The first, leading and second, trailing pairs of vertical brushes are positioned mid-length of the assembly. The vertical brushes are followed by the pair of transversely spaced apart brushes that is downwardly inclined at about a forty five degree (45°) angle. The pair of downwardly inclined brushes is positioned near the exit end of the assembly. The pair of upwardly inclined brushes counter-rotate in a downward direction, as does the pair of downwardly inclined brushes. The middle set of vertical brushes includes the leading pair of transversely opposed brushes that counter-rotate in a direction towards the entrance end of the housing and the trailing pair of transversely opposed brushes that counter-rotate in a direction towards the exit end of the housing. The vertical fluid headers associated with the vertical brushes are aimed at the brushes in cleaning relation thereto and not at the carcass. Each nozzle of each fluid header produces a flat, fan-shaped spray that enables the water or other liquid fluid to be aimed at its intended target to minimize wastage of said water or other liquid fluid. Each brush has short, medium length, and long bristles, also known as appendages, to enhance the cleaning power of the brush. An important object of this invention is to thoroughly clean the neck area of carcasses with a combination of water or other liquid fluid under pressure and mechanical brushing. A closely related object is to accomplish the foregoing object while using a minimum amount of water or other liquid fluid. A more specific object is to disclose the optimum arrangement of brushes and fluid headers in a neck washing apparatus. Still another object is to advance the art of brushes by disclosing bristles having greater cleaning power than the bristles of known brushes. These and other important objects, advantages, and features of the invention will become clear as this description proceeds. The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter and the scope of the invention will be indicated in the claims. BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which: FIG. 1 is a front elevational view of the novel neck washer assembly with the brushes depicted in diagrammatic form; FIG. 2 is a top plan view of the novel neck washer assembly; FIG. 3 is a first, entrance end elevational view of the neck washer; FIG. 4 is a second, exit end elevational view thereof; FIG. 5 is a perspective view of one-half the novel neck washer assembly, i.e., a perspective view taken along line 5 - 5 in FIG. 2 ; and FIG. 6 is a perspective view of the novel neck washer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2 , it will there be seen that an illustrative embodiment of the invention is denoted as a whole by the reference numeral 10 . Neck washer assembly, in this first embodiment, includes eight (8) brushes, four (4) of which are visible in the front view of FIG. 1 and all eight (8) of which are visible in the top plan view of FIG. 2 . More particularly, a pair of upwardly inclined brushes is denoted 14 , 14 a , a first or leading pair of vertical brushes is denoted 16 , 16 a , a second or trailing pair of vertical brushes is denoted 18 , 18 a , and a pair of downwardly inclined brushes is denoted 20 , 20 a. The brushes of each pair of brushes are transversely spaced from one another by a distance sufficient for a carcass neck to pass therebetween. More particularly, a carcass having a neck to be washed is suspended from an overhead conveyance and follows a path of travel between the paired brushes, traveling from left-to-right in the configuration as drawn. Brush 14 rotates in a counterclockwise direction and brush 14 a rotates in a clockwise direction in the assembly as drawn. This downwardly-directed counter-rotation causes the individual bristles of the brushes to travel from the back of a carcass neck towards the front thereof as the carcass enters the assembly at the left or entrance end thereof and travels toward the exit end of the assembly. The contaminants on a carcass neck are therefore brushed off the neck in a generally forward and downwardly direction by upwardly inclined brushes 14 , 14 a , beginning at a lower end of the neck and ending at an upper end thereof. Each bristle of brush 14 is an appendage that is mounted to a core 22 and core 22 is keyed to an elongate shaft 24 that is rotated by a motor and gearbox, collectively denoted 26 . Elongate shaft 24 is inclined upwardly at a forty five degree (45°) angle. Upwardly inclined brush 14 a has the same structure. Although a separate motor is dedicated to each shaft in this illustrative embodiment, both shafts could be rotated by a single motor having a couple of power-take-off belts or the like. Therefore, the term “motor means” includes at least one motor and does not require two motors. Each bristle of leading vertical brush 16 is an appendage that is mounted to a core 28 that is keyed to vertical shaft 30 that is rotated by a motor and gearbox that are collectively denoted 32 . Leading vertical brush 16 a has the same structure. Each bristle of trailing vertical brush 18 is an appendage that is mounted to a core 34 that is keyed to vertical shaft 36 that is rotated by a motor and gearbox that are collectively denoted 38 . Trailing vertical brush 18 a has the same structure. Vertical shafts 30 and 36 are disposed in parallel relation to one another. Motors 32 and 38 are connected in driving relation to vertical shafts 30 and 36 so that brushes 16 and 18 rotate at a common number of revolutions per minute (rpm) but in opposite directions. The same structure and rotation applies to brushes 16 a , 18 a. Each bristle of downwardly inclined brush 20 is an appendage that is mounted to a core 40 and core 40 is keyed to an elongate shaft 42 that is rotated by a motor and gearbox, collectively denoted 44 . Elongate shaft 44 is inclined downwardly at a forty five degree (45°) angle. Downwardly inclined brush 20 a has the same structure. After a carcass neck has traveled between and been brushed by upwardly inclined brushes 14 and 14 a , it passes between the leading set of vertical brushes 16 , 16 a . Said leading set of brushes counter-rotate with respect to one another in a direction that opposes the path of travel of the carcass neck. Thus, contaminants are brushed toward the entrance end of assembly 10 . The carcass neck then passes between the trailing set of vertical brushes 18 , 18 a . Said trailing set of brushes counter-rotate with respect to one another in a direction that follows the path of travel of the carcass. Thus, contaminants are brushed toward the exit end of the housing. The carcass then travels between downwardly inclined brushes 20 , 20 a that counter-rotate with respect to one another and brush contaminates in a downwardly direction. It will be observed in FIG. 1 that the bristles or appendages of the brushes are provided in three (3) differing lengths, i.e., long, medium-length, and short. These bristles of differing lengths are provided for all of the brushes, including the upwardly inclined brushes, the vertical brushes, and the downwardly inclined brushes. It has been determined that the cleaning efficiency of a brush is reduced if all of its bristles have a common length. The cleaning efficiency improves if half the bristles are long and half are short and still further efficiency is provided if one-third of the bristles are long, one-third short, and one-third of medium length roughly halfway between the lengths of the long and short bristles. There are two (2) fluid headers associated with each upwardly inclined brush 14 , 14 a , and each downwardly inclined brush 20 , 20 a . There is one (1) fluid header associated with each vertical brush 16 , 16 a , 18 , 18 a . Each fluid header is parallel to the axis of rotation of its associated brush. The fluid headers associated with the upwardly and downwardly inclined brushes are mounted in a common longitudinally-extending vertical plane so that an outer fluid header is directly above an inner fluid header. The fluid headers associated with the vertical brushes are mounted adjacent thereto. Each fluid header includes a plurality of equidistantly spaced apart nozzles along its length. In a preferred embodiment, each nozzle forms a flat, fan-shaped spray. The nozzles in each outer fluid header are aimed to impact the product, barely missing the outermost ends of the rotating bristles of the brushes so that the water or other liquid fluid from the outer fluid headers is dedicated to washing the product. The nozzles in each inner fluid header are aimed at the bristles or appendages so that the water or other liquid fluid from the inner fluid headers is dedicated to brush cleaning and so that the liquid fluid is applied to the brushes at the optimal moment. In FIG. 1 , the outer fluid header for upwardly inclined brush 14 is denoted 46 and the inner fluid header for said brush is denoted 48 . The flat, fan-shaped spray of water emanating from the nozzles of outer fluid header 46 is denoted 47 and just barely misses the radially outermost ends of the bristles of said brush 14 and impacts upon the carcass neck. The flat, fan-shaped spray of water emanating from the nozzles of inner fluid header 48 is denoted 49 and impacts the bristles of brush 14 , thereby cleaning said bristles. Fluid headers 46 a , 48 a operate in the same way for brush 14 a. The outer fluid header for downwardly inclined brush 20 is denoted 50 and the inner fluid header for said brush is denoted 52 . The flat, fan-shaped spray of water or other liquid fluid emanating from the nozzles of outer fluid header 50 is denoted 51 and just barely misses the radially outermost ends of the bristles of said brush 18 and impacts the carcass neck. The flat, fan-shaped spray of water or other liquid fluid emanating from the nozzles of inner fluid header 52 is denoted 53 and impacts the bristles of said brush 20 , thereby cleaning said bristles. Fluid headers 50 a , 52 a operate in the same way for brush 18 a. The fluid headers associated with vertical brushes 16 , 16 a , 18 , and 18 a are aimed to clean their associated brushes and are not aimed at the carcass. One of the fluid headers is depicted in FIG. 5 and is denoted by the reference numeral 5 . As perhaps best depicted in FIG. 5 , a plurality of horizontally-disposed static guides, denoted 60 a - h is provided to keep the carcass traveling through machine 10 a safe distance from each brush. Each static guide is a solid stainless steel plate, about three-eighths of an inch (⅜″) in thickness. Each static guide has the appearance of a shelf; each is mounted to an upstanding framework of the novel machine and extends perpendicularly from said framework toward the center or longitudinal axis of symmetry of the machine. Static guides 60 a - h eliminate “trap” or “pinch” points that might impede the progress of the carcass though the machine. In FIG. 5 , top static guide 60 a extends horizontally substantially the entire extent of the housing. Three (3) static guides are mounted below top static guide 60 a at about the same height as the upper end of the upwardly and downwardly inclined brushes. Leading static guide 60 b is positioned in leading relation to the first upwardly inclined brushes, middle static guide 60 c is positioned between the upwardly and downwardly inclined brushes, and trailing static guide 60 d is positioned in trailing relation to the downwardly inclined brushes. A mid-level static guide 60 e extends between the upwardly and downwardly inclined brushes, and a low-level static guide 60 f is near the bottom of the assembly and between said upwardly and downwardly-inclined brushes. Two (2) very truncate static guides 60 g and 60 h are positioned at the leading and trailing ends of the housing at a height slightly above that of mid-level static guide 60 e. Each static guide 60 has a counterpart on the opposing half of the structure that is not depicted in FIG. 5 . The brushes are not depicted in FIG. 5 to better reveal the various parts of the novel housing. Note that the leading edge of each static guide is beveled, i.e., swept back so that a carcass abutting a static guide does not get stuck or impeded by the static guide. The trailing edge of each static guide is not beveled. Novel housing 10 is secured in spaced apart relation to an upstanding wall 70 . A plurality of stand off assemblies, collectively denoted 72 , have a flat base plate secured to vertical wall 70 , a similar plate secured to the framework of housing 10 , and a horizontally disposed stand-off member therebetween. Said three (3) individual parts of said stand-off assemblies 72 are easily seen in FIG. 5 and are not separately numbered to avoid cluttering of the drawings. The entrance end view of FIG. 3 depicts the transverse spacing between brushes 14 , 14 a , said spacing being the same for all of the other transversely-spaced sets of brushes as well. This is the space through which the carcasses travel from left-to-right as drawn in FIG. 1 . Deflection plates 74 , 74 a at the entrance end of the apparatus steer the carcass towards the center of the apparatus, as perhaps best depicted in FIGS. 2 and 3 . It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.

An apparatus for washing the neck area of an animal carcass includes a pair of upwardly inclined brushes sharing a common angle of inclination, followed by a first pair of vertically disposed brushes, a second pair of vertically disposed brushes, and by a pair of downwardly inclined brushes sharing a common angle of inclination. The brushes of each pair of brushes are transversely spaced apart from one another to accommodate an animal carcass between them. First and second fluid headers are positioned in parallel relation to each inclined brush. A neck area of a carcass is initially cleaned by the pair of upwardly inclined brushes and associated fluid headers. The neck area then passes between the first and second pair of vertical brushes and associated fluid headers. The final cleaning is administered by the pair of downwardly inclined brushes and their associated fluid headers.

This is a continuation-in-part of application Ser. No. 484,198, filed June 28, 1974, now abandoned. PRIOR ART AND BACKGROUND OF THE INVENTION Oranges and grapefruit have been packaged in bags at the shipping point for more than three decades in Florida. For about 20 years it was all done manually. Only fabric mesh bags were used before polyethylene film bags, which first appeared in Florida statistics for the 1958-1959 season. Polyethylene net bags first appeared in Florida statistics for the 1966-67 season. In Florida most citrus bagging in polyethylene film bags is done by semiautomatic machinery: limited automatic machines are in use. In all semiautomatic bagging operations, purchased (premanufactured) bags are used entirely. The semi-automatic equipment used by the larger portion of the packinghouse counts the desired quantity of fruit into the bag upon actuation of a foot pedal or other control by the operator. The operator holds the bag in position to catch the fruit, then closes it by a tape or stapling device, and places it in a master carton. Similar semiautomatic equipment is used elsewhere for packaging such produce as apples, onions, and potatoes in polyethylene film bags. Generally, this equipment measures quantity by weight instead of count. Machine action or the operator pours the measured quantity from a pan or accumulating chamber into the bag after the machine feed has stopped at a preset weight. Bag closing practices are similar to those employed on semiautomatic citrus bagging operations. Semiautomatic machines suitable for polyethylene film bags are also generally usable for bagging fruit in polyethylene net bags. Automatic polyethylene film bagging machines have been installed in several Florida packinghouses over approximately the past three years. Premade bags are used by all of them except for one make that uses specially prepared film, doubled, in a ribbon with perforations in heat-sealed strips betweem bags. The bagging machine heat-seals the top after filling except where twist-tie or Kwik-lok closing has been substituted. Bags separate along perforation lines in passing out of the machine onto the takeaway conveyor. Manual checking of bag weight is required in operating one make of these machines, a carrousel type. No fully automatic machines are available for handling polyethylene net bags except one type, recently offered in the Florida citrus area, with an attachment for automatically handling net bags supplied on wire frames. Thus far, the tooling of bagmakers has not provided for supplying polyethylene net bags in this way. Since manufactured polyethylene net bags cost about twice as much as film bags, there would be an economic as well as many other advantages accruing to consumers and packers alike by having bag forming incorporated into an automatic cycle of bag filling and closing machinery. These concepts were emperically tested and evaluated by constructing an experimental machine. Testing of the machine was confined to packing 5-pound bags of oranges because of their lead in shipment of Florida citrus fruit in polyethylene net bags. The machine is adaptable, however, to other bag sizes, produce, and applications. OBJECTIVES One of the objectives of this machine is to eliminate the need for preformed bags. Another objective is to make a totally automatic citrus bagging machine. Another objective is to incorporate the bag forming into the automatic cycle. It is yet another objective to eliminate the need for manual labor in any of the weighing and bagging operations of citrus packaging. Another object of this invention is to reduce the cost of packaging of citrus fruits. Still another object of this invention is to supply a means of packaging other types of produce. GENERAL DESCRIPTION OF THE INVENTION Polyethylene bagging material is initially manually fed into the automatic bag-forming portion of the automatic bagging machine when a new roll of netting is installed. This is done by hand feeding the netting material through the bottom ring around the spreading mandrel, thus positioning it to begin the automatic bag-forming operation. The solenoid actuates the spreader thereby positioning it to subsequently spread the netting by allowing for entry of the spreading fingers in the gripping head. The spreading fingers of the gripping head are positioned to the center of the cross head thereby enabling the cross head to be lowered in such a manner that the fingers are inserted into the center of the polyethylene netting material. The fingers contact the top of the spreading mandrel causing the top of the spreading mandrel to be repositioned. The gripping fingers are then actuated to an out position thus opening the top of the netting material to allow for produce entry. The cross head then moves up the full length of a bag (approximately 19 inches) pulling the netting material with it. Then the bottom gathering, closing, and cutting mechnism swings in. The bottom gathering arm gathers the material and after gathering the material it actuates a micro switch which staples and then cuts the bag thus forming the bottom of the bag. The bottom gathering, closing and cutting mechanism then swing out and simultaneously the chute drops down to support the fruit which is then going to automatically be counted into the open bag. The automatic counter then counts the desired amount of produce into the bag, as previously programmed (approximately 11 to 13 oranges). This can be any amount of fruit or produce which can be programmed for bagging. After counting the produce into the bag the counting machine signals the bagging machine to start closing the top again. The gripping belts enter under the gripping head. The gripping belts have two arms which forces the hot wire in. The hot wire then cuts the netting off the gripping fingers. Then actuate the belt and move the net into the top closing mechanism. When the net moves into the top closing mechanism far enough it signals the photoelectric cell (triggers the photoelectric cell). The photoelectric cell actuates the gathering arm and causes the gathering arm to move in and gather the material (polyethylene material). When the material has been gathered, the micro switch is actuated thereby actuating the stapling mechanism. The stapling mechanism then staples the material together at the top and simultaneously the chute pan automatically moves up into position to allow the bag to slide forward and down. It is thus ejected. The machine then repeats the same operations previously described. DETAILED DESCRIPTION OF INVENTION In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operates in a similar manner to accomplish a similar purpose. Machine dimensions, materials of construction, control devices, operating configurations and applications illustrated are typical only and all other more sophisticated equivalents are also intended. FIG. 1 is an exploded isometric view showing the bagging machine. FIG. 2 is an exploded view of the lower portion of the automatic bagging machine detailing the assembly of the opening and closing mechanism and the opening and gripping mechanism in relation to the spreading mandrel. FIG. 3 is an isometric view of the gripping fingers in the spread open position. FIG. 4 is an illustrative drawing showing the position of the gripping fingers in both the open and closed position. FIG. 5 is an isometric view of the spreading mandrel and the tripping mechanism with the polyethylene net tubing superimposed over the exterior. FIG. 6 is an illustrative cross-sectional drawing of the spreading mandrel in the down or collapsed position. FIG. 7 is an illustrative cross-sectional view of the spreading mandrel in the expanded or up position. FIG. 8 is an isometric view of the top gathering and closing mechanism. FIG. 9 is an illustrative view of the transfer belt arms in the open position. FIG. 10 is an illustrative view of the transfer belt in the closed position. FIG. 11 is an isometric view of the bottom gathering, closing and cutting mechanism. FIG. 12, Detail A is a detail of the internal workings with respect to FIGS. 6 and 7. FIG. 13, A through G, is an illustrative cross-sectional view of the machine action sequences. In the preferred embodiment of the invention, polyethylene net tubing is supplied by the manufacturer on a roll in continuous form. Reference is made to FIGS. 1 through 12. The end of the polyethylene net tubing on roll 13, FIG. 1, is manually fed into the automatic bag forming machine by inserting the net material through base plate 40 and ring 5, and around spreading mandrel 6, FIGS. 1, 2, and 5, thus positioning it to begin the automatic bag-forming cycle. Spreading mandrel 6, FIGS. 5, 6, and 7, is of a cylindrical design and floats free inside ring 5, which is mounted to base plate 40. FIG. 5. Base plate 40 has a hole for the polyethylene net tubing to pass through. This hole is smaller than the circumference of the mandrel thus holding the mandrel in place above the base plate. The trippers 7, FIG. 5, are actuated by the solenoid 14, positioning the spreading mandrel 6, FIGS. 5, 6, and 7, to subsequently spread the netting and allow for entry of the opening and gripping mechanism 8, FIGS. 1, 2, 3, and 4. The spreader mandrel operates as follows: Solenoid 14, FIG. 5, connected to tripper 7, which pivots on screw 46, and is mounted on frame 42, attached to plate 40, by rod 41, actuates tripper 7 which pivots at base plate 40 and comes into contact with locking pin arm 54, FIG. 6, pulling locking pin 53, FIG. 6, up and out of locking groove 59, thereby releasing the top of the spreader mandrel 50, to be forced upward by spring 51, thus resulting in expanded position as shown in FIG. 7. Simultaneously, locking pin spring return 57, FIG. 12, detail A, forces locking pin 53 back into ready position. The expanded position is fixed by the top mandrel locking shoulders 60, contacting with locking screws 52, FIGS. 6 and 7. This position is necessary to receive the gripping mechanism of the automatic bagging machine. Simultaneously, trippers 7, FIG. 5, are returned to resting position by return spring 44, which is attached to return spring anchor mount 45, which is attached to solenoid 14, FIG. 5. A cam timer on the automatic bagging machine signals a gripping mechanism which is part of the bagging machine bringing the gripping mechanism into contact with the top of the spreader mandrel 50, FIG. 6, forcing the top of spreader mandrel 50, FIGS. 6 and 7, downward. As top spreader mandrel 50, is forced downward, the bevel on the top internal pop-up section 61, contacts locking pin 53, shoves it outward, and allows pin 53 to insert into groove 50, thereby repositioning and resetting spreader mandrel 6, as shown in FIG. 6, which is the initial starting position. The polyethylene netting material can then slide between the exterior surface of spreader mandrel 6, FIG. 5, and stationary guide ring 5, FIG. 6. The opening and gripping mechanism 8, is then positioned to the center of the cross-head which is then lowered in such a manner that the fingers of the opening and gripping mechanism 8 are inserted into the center of the polyethylene netting material. This position of sequence is represented on sequencing graft 13 as sequence 13 A. Opening and gripping mechanism 8 is attached to cross-head frame 17 which is mounted to vertical rods 90 which are rigidly mounted to the outer frame for support. The cross-head 17 thus moves up and down guided by vertical rods 90 for vertical movement and alignment. Gripping fingers 26, FIG. 3, move in and out actuated by air cylinders 12 for horizontal movement, FIGS. 1, 2, 3, and 4. The opening and gripping mechanism operates as follows: Air cylinders 12 are attached to cylinder rod 25, FIG. 3, which is attached to pivot block 3, using connecting screw 24, which is attached to cross members 1 and 2. The forward ends of cross members 1 and 2 have cylindrical vertical gripping fingers 26 attached at 90° angles to said cross members 1 and 2. The aft end of cross members 1 and 2 are secured by slide action bushing 31, FIG. 4, and a screw through the cross member. Cross member 2 has a spacer 30, FIG. 3, on the secured aft end. This spacer 30 is slightly thicker than the cross member 1. It is the function of this spacer to allow for horizontal leveling of cross member 2. Since it is the basic function of the gripping surfaces to grip and hold the polyethylene bagging in place during the automatic machine cycle, this operation takes place as follows: air cylinders 12 are actuated forward. This causes cylinder rod 25, FIGS. 3 and 4, to move forward. Since it is attached to pivot block 3 which is attached to cross members 1 and 2 at 2/8 inches forward of the center of the cross bar, the forward end with the gripping fingers 26, FIGS. 3 and 4, moves forward to the center of frame 27, FIGS. 3 and 4, aligning themselves in the entry position 33, FIG. 4. Simultaneously, the aft secured end rides the slide action bushing 31, FIG. 4, along slots 28, FIG. 4, such that the aft ends come together in alignment, thus completing a closing cycle. The opening cycle takes place by the direct reverse of the operation described above. Air cylinders 12 move rod 25, FIGS. 3 and 4, backward causing gripping fingers 26, FIGS. 3 and 4, to move backward bringing gripping fingers 26 and gripping surface 29, FIGS. 3 and 4, together with the polyethylene net tubing held firmly between fingers 26 and gripping surface 29, FIGS. 3 and 4, thus completing a full open and closing cycle. The entire gripping head assembly is capable of being lowered and raised during the bag-forming cycle of the automatic bagging machine. In this manner the cross-head is moved upward the full length of a bag (approximately 19 inches) pulling the polyethylene netting material with it, to machine action sequence 13B. At this point air cylinders 12, actuates swing mounting and air stapler 10, FIGS. 1, 2, and 11, causing 10 to swing in, to allow for gathering stapling and cutting of the polyethylene net bag and thus form a bottom. The gathering, cutting and stapling apparatus as shown in FIG. 11 is mounted for swinging horizontally on vertical rod 91 which is attached to the supporting frame. A signal to the solenoid opens the air to air cylinder 12 which is a gathering and cutting cylinder, FIG. 11. The gathering arm 70, gathers the polyethylene material into V-notch 21, and microswitch 71, opens the air to the stapler stapling the polyethylene netting forming a closed net at the bottom. Automatically a knife 72 swings under the V-notch 21, severing the polyethylene net just below the stapled netting. Then swing mounting and air stapler 10 swing back out to initial position. Simultaneously, the chute 4, FIGS. 1 and 11, drops down to support the produce which is then counted automatically into the upper open end of the bag (this sequence is represented by machine operation sequence 13D). After counting the produce into the bag, the counting machine (which can be any commerical grade weighing and counting machine) signals the bagging machine to actuate the top gathering and closing mechanism 15 which is swing mounted to the top of the support frame, FIGS. 1 and 8. The gripping belts 16, FIG. 8, enter under the gripping frame 17, FIGS. 1 and 2. The gripping belts have two transfer belt arms 18, FIG. 8, with a hot wire attachment 19, FIG. 8. The transfer belt arms 18, forces the hot wire 19, into contact with the polyethylene netting thus severing the netting from the gripping fingers 8. FIGS. 1 and 8, this point of bag forming is represented by machine diagram sequence 13E. These actuate the gripping belts 16, FIG. 8, and move the net into top closing mechanism 15, far enough to trigger the photoelectric cell 80 which actuates the top gathering arm 20, which gathers and staples the net material by triggering the V-notch stapling mechanism 21, FIG. 8. Simultaneously, the chute pan 4, FIG. 1, automatically moves up into position to allow the bag to slide forward and down, see machine operational sequence FIG. 13F and 13G, thus ejecting it. The machine then automatically repeats the same operations above described for another cycle thus forming another bag, filling the bag, stapling, and ejecting.

A produce-bagging machine utilizing factory-roll polyethylene net tubing for automatic packaging is described. The bagging machine is designed to form bags from factory rolls of polyethylene net tubing, fill the bags with produce, and close and eject them in a continuous automatic cycle. The machine consists of seven main parts: (1) an opening and gripping mechanism, (2) a bottom-closing and cutting mechanism, (3) a filling device, (4) a top-closing mechanism, (5) an ejection chute, (6) automatic action controls, and (7) a spreading mechanism.

BACKGROUND OF THE INVENTION This invention relates to lubricants for internal combustion engines. More particularly, the invention is directed to a solid lubricant which is introduced into and is dispersible within the liquid fuel system of an internal combustion engine for delivery to fuel-contacting moving parts, to coat and to lubricate such parts. In a preferred embodiment of the invention, the pellet includes, in addition to a mixture of metal components, the salt molybdenum disulphide. The prior art is replete with formulations of many types for the lubrication of engine components, including engine parts in internal combustion engines. Such lubricants have taken various physical forms including oils and greases as well as oil and grease compositions in which solids such as graphite have been dispersed or suspended. In addition, grease-like lubricating compositions which include the lubricant molybdenum disulphide are also known. Coupled with a wide diversity in the compositions themselves, various different techniques have been invoked in distributing or applying the lubricant to the areas to be treated. Such techniques have conventionally included incorporation of the lubric material in the engine crank case. In other procedures gasoline-soluble liquid phase lubricants have been added directly to the fuel supply. In spite of extensive experimentation, developmental work and research carried out, no technique and no lubricating composition has proved completely satisfactory for the purposes intended. It is, therefore, the aim of the present invention to provide both a new type lubric composition and a new method of applying that composition to internal moving engine parts, particularly those parts associated with the combustion chamber of an internal combustion engine. It is a principal object of the invention to provide, in a lubric composition, an improved physical form constituting a solid pellet which is introducible into for dispersion through the fuel so as to reach and lubricate those components of the internal combustion engine normally contacted by the fuel phase. It is a related object of the invention to provide an improved lubric composition which is operative to deposit a highly effective lubricating film as a low-friction interface between moving parts of an internal combustion engine including such parts as cylinder walls and piston rings, valve stems and sleeves, and valve guides. It is an important feature of the invention that the pellet lubricant is effectively dispersed in a fine particulate form and that the minute particles are, thereupon, delivered directly to lubrication requiring surfaces in an internal combustion engine to produce a highly-adherent pressure-resistant film of solid lubricant as a wear detering anti-friction coating. Yet another object of the invention is to provide a fuel-carried composition which is effective to fill in and to smooth surface irregularities of moving metallic components of an internal combustion engine, which components have become worn, pitted, or eroded in use. Still another object of the invention is to provide a solid pellet, disintegratable within the fuel system of an internal combustion engine, to provide a distribution of fine particulate metallic-like elements effective to produce a plating-like coating on the moving and wear-subjected surfaces of an internal combustion engine. It is an important feature of the improved solid lubricant of the invention that it is impervious to the deleterious effects of high temperatures and pressures which ordinarily destroy or render liquid lubricants ineffective. Still another important feature of the improved lubricant of the invention is that it is effective over an extended time period, the availability of the lubric particles being time sustained and being a function of the time-related "erosion" of the lubric pellet in the gasoline tank of the internal combustion engine. It is a related object of the invention to provide a lubricant which is automatically and continuously dispersed and distributed as needed, without any attention being required from the vehicle operator or the servicing attendant. Still another feature of the improved composition of the invention is that it is effective to establish a fluid-sealing coating on opposed sliding surface elements in an internal combustion engine, thereby to increase the compression values in the cylinders of such engines. A related object of the invention is that the solid lubricant minimizes transport of lubricating oil from the crank case past the piston rings to the combustion chamber, thereby reducing significantly air pollution associated with the undesirable combustion and exhaust discharge of oil and oil breakdown products. SUMMARY OF THE INVENTION The novelty of the solid lubricant of the present invention lies not only in its form and its composition, but also in the manner in which the lubricant is distributed to the areas where it is to function. More specifically, the invention, in its preferred embodiment, constitutes a pill or pellet consisting of an intimate mixture or alloy of various metals in conjunction with a solid lubricant constituting a metallic salt, molybdenum disulfide being preferred. The physical pellet itself is, for example, prepared from a mixture of finely divided metal components plus the lubricant salt, all molded together to form an integral unitary mass. The resulting pellet, which is conveniently about 10 grams in weight, is introduced into the fuel tank where it undergoes physical abrasion by means of contacting the pellet with internal wall faces of the fuel tank through engine vibration or otherwise disintegrates over an extended period of time to disperse throughout the fuel system as finely divided particulate matter which is most effective as a surface-bonding plating and as a solid lubricant. The lubricant is not adversely affected by either high temperatures or high pressures and, in this sense, is highly superior to the more conventional oil or grease-like compositions. The above and other objects, features, and advantages of the invention may be more clearly understood upon a review of the detailed description of the preferred embodiments. Such embodiments are presented here only as examples and are not to be considered as limiting the invention in any way. DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with a preferred embodiment of the invention, the aims and objects are accomplished by providing a molded pellet of solid lubric material, the pellet being formulated so as to be susceptible to abrasion within the fuel tank of a vehicle whereby the pellet undergoes a disintegration process to produce extremely fine particulate matter which is then distributed by the fuel to the combustion zone within the internal combustion engine. The lubric particles coat abutting moving surfaces with a fine lubricating or friction-reducing film while at the same time filling in and smoothing declivities, pittings and corroded areas in these surfaces. The overall effect is to cure or to ameliorate surface defects while simultaneously ensuring a high degree of interface lubricity thereby to minimize surface-to-surface friction and wear. A specific composition which has been found to be particularly effective as a solid lubricant in an internal combustion engine in its critical cylinder and valve areas is the following, the relative proportions being in parts by weight. EXAMPLE I ______________________________________ tin 64 lead 30 bismuth 2.5 copper 1.0 antimony 0.8 zinc 0.7 molybdenum disulfide 0.2______________________________________ While the above formulation is preferred, the components are not critically restricted to the precise percentages or ratios indicated. For example, the amount of molybdenum disulfide may vary within the range of about 0.01 to about 10% by weight. The molybdenum disulfide itself is preferrably highly purified and of a colloidal nature thereby to ensure that no abrasive or other type of objectionable impurity is present which could impair the antifriction properties of the final preparation. Each of the components set forth in Example I above may be varied within significant limits without appreciably or adversely affecting the overall effectiveness of the invention. The acceptable quantitative ranges for each component are indicated below in Example II, the numerical values designating parts by weight. EXAMPLE II ______________________________________ tin 50-75 lead 25-50 bismuth 1-5 copper 0.5-2 antimony 0.1-1.5 zinc 0.1-1.5 molybdenum disulfide 0.1-10______________________________________ As substitutes for, or to be used in conjunction with the molybdenum disulfide solid lubricant, other materials may be utilized. These include the disulfides, selenides and and tellurides of molybdenum, tungsten, and titanium, either individually of in combination. Each of these materials has been found effective to deposit on the cylinder walls, piston rings, valve stems and valve guide surfaces an adherent lubricant film-like coating guaranteeing an extremely low friction coefficient between moving contacting parts. An important advantage achieved through the use of the present invention is a functionally significant increase in the cylinder compression readings. Typical improvement of the type realized is indicated in the data set forth below. In an eight cylinder internal combustion engine, the compression values for each cylinder prior to use of the composition of the invention was 130-135-135-140-135-135-135-135. These compression values increased to the following readings upon use of the solid lubricant of the invention 140-135-140-140-140-135-135-140. While at first view the changes might appear not to be significant, it must be appreciated that the compression increase was simultaneously accompanied by improved lubrication and lower coefficients of friction between the moving parts, all contributing to improved engine operation, extended useful engine life, and increased mileage. In preparing the solid lubricant of the invention the various metals are combined in particulate form and the solid lubricant incorporated and distributed uniformly therethrough. The homogeneous mixture is then molded as in a fusion casting process and the resulting pellets are discharged as discrete units weighing about 10 grams each. It has been found that, in normal use, the addition of one of these pellets to the fuel system by introduction into the fuel tank at intervals of about 12,000 miles of driving is effective to accomplish the purposes of the invention. No detrimental or objectionable effects will result, however, through more frequent use of the pellets. When used in accordance with the teachings of the invention, the solid lubricant obviates the adverse effects produced by excessive friction, and minimizes wear of engine parts. While disclosure of preferred embodiments of the lubricant and of preferred methods for formulating and producing the pellet lubricant of the invention have been provided, it will be apparent that numerous modifications and variations thereof may be made without departing from the underlying principles of the invention. It is, therefore, desired by the following claims to include within the scope of the invention all such variations and modifications by which substantially the results of this invention may be obtained through the use of substantially the same or equivalent means.

A solid lubricant consisting of metals combined with a high lubricity salt fabricated in pellet form and introduced into the fuel reservoir of an internal combustion engine. The pellet slowly disintegrates to produce extremely minute solid particles which are dispersed in the fuel and delivered to the fuel-contacting engine parts of the engine to deposit a lubricant film thereon.

FIELD OF THE INVENTION The present invention relates to expandable borehole plugs and to the fixing of such plugs within a borehole for placing explosives or stemming. BACKGROUND OF THE INVENTION Drilling and blasting operations are used for controlled rock removal in mining, road construction, tunnelling, and rock sculpturing. Strategically spaced holes are drilled into the rock, powder charges are placed in the holes, the holes are sealed by back-filling with loose rock or other "stemming" material, and the charges are detonated. Diagram FIG. 1 shows the cross section of a typical prepared basic blast hole configuration. For some blasting situations it is desireable to use air decking, a technique which provides an air space between the powder charge and the stemming material, as typically shown in FIG. 2. The air space allows blasting forces to be exerted over a greater length of the drill hole while using a reduced powder charge. A plug is used to suspend the stemming material above the powder charge, thereby creating the air space. An ideal plug completely seals the hole to prevent gasses from pushing upwards or "rifling" out of the blast hole. This results in maximum force application to the rock surface within the blast chamber. In some cases, desirable effects are obtained by using multiple powder charges in the same blast hole, separating the charges with multiple plugs as typically shown in FIG. 3. In others, it is desireable to blast the hole in sections starting at the top and working downward. For these situations, the hole must be plugged a certain distance from the top to allow for the upper section of rock to be blown away first. A positive seal is needed for these operations to ensure that the force of the blast does not push downward into the bottom of the hole. Sand is filled in on top of the plug and stemming material is back-filled on top of the powder to help divert the force of the blast outward, into the rock, as typically shown in FIG. 4. Escaping gasses, blown upwards around blocking mechanisms and through stemming material during detonation, may reduce the effectiveness of blasting. The most effective air decking blocking mechanisms, or plugs, are therefore those which provide positive gas sealing capabilities. Therefore, there is a need for a safe, easy to use, inexpensive way to provide an air-tight borehole seal for use in blasting applications. SUMMARY OF THE INVENTION The present application provides for a borehole decking plug which is created by a self-expanding plastic foam. Two closed waterproof pouches, an inner pouch and an outer pouch, each contain a separate component of the foam. The inner pouch is contained within the outer pouch, and both are contained within a third open external pouch having a tether attachment. Upon breaking the inner pouch, the separate foam components combine within the outer pouch to form a complete expansion foam. The foam expands slowly enough to provide sufficient time for the device to be lowered via the tether down a borehole to a preselected position. Once in position, the expansion foam bursts the outer pouch and escapes upward through the external pouch to form a deck plug at the preselected position. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cut-away view of a typical prepared basic blast hole configuration. FIG. 2 is a cut-away view of a typical prepared basic blast hole configuration with air decking. FIG. 3 is a cut-away view of a typical prepared basic blast hole configuration with multiple air decking. FIG. 4 is a cut-away view of a typical prepared basic blast hole configuration with a suspended charge. FIG. 5 is a perspective view showing an inner and an outer pouch of a typical borehole decking plug. FIG. 6 is a plan view showing an inner pouch, an outer pouch, and an open external pouch of a typical borehole decking plug. FIG. 7 is a plan view showing an inner pouch, an outer pouch, and an open external pouch of a typical borehole decking plug for underwater use. FIG. 8 is a cut-away view of a typical overhead borehole configuration. FIG. 9 is a cut-away view of a typical overhead borehole configuration for cable anchoring. DETAILED DESCRIPTION In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. The present invention provides for a borehole decking plug with the following advantages over prior art devices and methods: 1. The foam components are sealed so the operator is not subject to exposure. 2. The foam components are easily mixed inside a self-contained pouch. 3. Control of mixing is maintained with predetermined levels of components. 4. Reliability is improved by maintaining an accurate mix of components providing optimal foam creation. 5. Color coded foam components provide the operator with a visual reference of mixing. 6. The self-contained foam components reduce the amount of time required to mix and load. 7. Elimination of waste products such as mixing heads and syringes. 8. An external pouch which assists in creating adhesion of the deck plug to the walls of the borehole. 9. Elimination of metal parts that could create sparks. 10. Modifications that provide for underwater operation. The present invention is useful in creating a borehole decking plug in many different types of blasting applications and configurations. FIGS. 1-4 show the context of the invention. The borehole decking plug of the present invention may be substituted for prior art plugs in the locations shown in the figures. FIG. 1 shows a cut-away view of a typical prepared basic blast hole configuration. A powder charge is placed at the bottom of the borehole with stemming placed directly above the charge in order to control the effects of the blast. No borehole plug is used in this configuration. FIG. 2 shows a cut-away view of a typical prepared basic blast hole configuration with air decking. A powder charge is placed at the bottom of the borehole with a borehole plug placed at some distance above the charge, creating an air space between the charge and the plug. Stemming is placed directly above the plug in order to prevent rifling and control the effects of the blast. FIG. 3 shows a cut-away view of a typical prepared basic blast hole configuration with multiple air decking. As in FIG. 2, a powder charge is placed at the bottom of the borehole with a borehole plug placed at some distance above the charge, creating an air space between the charge and the plug. Although not required, stemming may be optionally placed directly above the plug to a point below the top of the borehole. A second powder charge is placed on top of the optional stemming with a second borehole plug above it creating a second air space above the second charge. Stemming may then be optionally placed directly above the second plug, and further charges, plugs, and optional stemming may then be added as necessary. FIG. 4 shows a cut-away view of a typical prepared basic blast hole configuration with a suspended charge. A borehole plug is placed at some distance above the bottom of the borehole, creating an air space in the lower portion of the borehole. Sand is placed directly above the plug, and a powder charge is placed directly on the sand. Stemming is then placed above the charge in order to control the effects of the blast. FIG. 8 describes a cut-away view of a typical overhead borehole configuration. Typically used in underground mining applications, a borehole 801 is drilled upwards from a horizontal shaft of the mine 805. A pole or some other means is then normally used to place explosives up into the overhead borehole, and a decking plug 803 is typically placed at the bottom of the borehole to seal off the bottom of the borehole from the horizontal mine shaft. FIG. 9 describes a cut-away view of a typical overhead borehole configuration using cable anchoring. As with FIG. 8, this is typically used in underground mining applications to provide support for the ceiling of a horizontal mine shaft in order to prevent the collapse of the ceiling. Two overhead boreholes are normally drilled upwards some distance apart within a horizontal mine shaft. A number of cables 901 are typically inserted into the borehole, along with a grout tube 903 and a breather tube 905. A stem plug 907 is then usually placed at the bottom of the borehole to seal off the bottom of the borehole from the horizontal mine shaft. Grout is then typically pumped into the borehole through grout tube 903, and the air within the sealed borehole which is displaced by the grout is allowed to escape through the breather tube 905. The stem plug 907 prevents grout from falling out the bottom of the borehole into the horizontal mine shaft. Once the grout hardens, the cables 901 are firmly anchored within the borehole. FIG. 5 is a perspective view of a borehole decking plug compatible with the present invention. An inner pouch 101 containing a first expansion foam component 107 is sealed inside of an outer pouch 103 containing a second expansion foam component. The inner pouch 101 and outer pouch are sealed along a seal 105. The pouches are typically made from tubular plastic film, are waterproof (liquid impervious), and are substantially clear so that their contents may be observed by an operator. The seal 105 joining the inner pouch 101 and outer pouch 103 allows the operator to easily grasp the inner pouch 101 within the outer pouch 103, preventing the inner pouch 101 from sliding around within the outer pouch 103 making it difficult to grasp. Further, the inner pouch 101 is typically made of thinner film than the outer pouch 103, such that the inner pouch 101 will break before the outer pouch 103 when mechanical pressure is applied. FIG. 6 shows how the inner pouch 101 and outer pouch 103 are held by an external pouch 111 ("diaper") which prevents the expanding foam from falling downward into the borehole when the outer pouch 103 bursts from foam expansion. The foam typically forms a decking plug with a positive seal by filling the external pouch 111 and expanding upward to adhere to the walls of the borehole. The external pouch 111 is typically made from plastic film, similar to the inner and outer pouches 101, 103, and is sealed around the outer pouch at 113. Additionally, the external pouch 111 normally provides a handle 115 to which a tether can be attached for suspending the device at a predetermined level within the borehole. FIG. 7 shows an alternative embodiment of the present invention for use with underwater blasting applications. The underwater embodiment is similar to that shown in FIG. 6, but typically uses a different structure for the external pouch 111. The external pouch 111 normally extends upward and is sealed at 121, forming a roof above the inner pouch 101 and outer pouch 103 containing expansion foam A and B components 107 and 109. The external pouch 111 typically contains a number of holes 119 located substantially between the mid-point and a point below the top edge of the external pouch 111, which allow water to be pushed out by the foam as it expands upward. An additional flap 125 is preferably sealed at 123 onto the inner pouch 101 and outer pouch 103 inside the external pouch 111. A cord 129 with a tether attachment 117 is normally fastened to the flap 125 at 127. This provides a means of attaching a tether for suspending the device at a certain level within the borehole. Once the expansion foam components are mixed, the device is typically lowered under water into the borehole. The device may optionally be weighted, such as with sand, in order to provide greater negative buoyancy. Once in position within the borehole, the expansion foam normally bursts the outer pouch 103 and seals the lower portion of the external pouch 111 to the walls of the borehole. As the foam continues to expand, it typically rises to the top of area 121 of the external pouch 111. As there are no holes in the very top portion of the external pouch 111, the foam expands outward, typically sealing to the walls of the shaft and pushing water from within the external pouch 111 through the open holes 119. The preferred embodiment of the present invention contains no metal parts, such as air valves or fittings, that could create sparks and prematurely set off a charge. The preferred two-part expansion foam typically comprises an isocyanate (A) compound and a polyol resin (B) compound. The preferred embodiment of the present invention uses foam FE 630-2.0 from Foam Enterprises, Inc., Minneapolis, Minn., but it will be recognized that other expansion foams with similar expansion characteristics, either polyurethane or non-polyurethane based, may be substituted for the FE 630-2.0 foam without loss of generality. The A component acts as a catalyst and typically has a density of approximately 10.3 pounds per gallon (ppg). The B component may be of many different types of polyol resin blends, and typically has a density of approximately 10.2 ppg. The A component is typically visually dark in color, while the B component is typically visually more clear. It will be recognized that any number of chemically inert coloring agents may be added to either the A or B component in order to provide a stronger or different visual cue to aid an operator in mixing the components. When combined, the A and B components typically expand to approximately 33 times the volume of their liquid state, resulting in a foam with a density of approximately 2.5-3.1 pounds per cubic foot (pcf) and a compressive strength of approximately 23 pounds per square inch (psi). In hot weather, at approximately 95° fahrenheit, the rise time is typically 10-20 seconds, the gel time is 30-55 seconds, and the tack free time is 50-80 seconds. In warm weather, at approximately 75° fahrenheit, the rise time is typically 20-30 seconds, the gel time is 80-95 seconds, and the tack free time is 100-125 seconds. In cold weather, the rise time, gel time, and tack free time are typically 20-30 seconds longer than the corresponding warm weather times. On average, a usable foam plug is formed 40-60 seconds after mixing the A and B components. It will be recognized that the foam density and reaction times are dependent on mix efficiency, temperature, and resultant foam thickness, and that the present invention accommodates a wide variation in these factors without loss of functionality. The chemistry of the foam may be adjusted for optimum performance, but a typical ratio of component A to component B of the foam is approximately 4 to 3. The amount of component A may be increased or decreased depending on the application. Increasing the proportion of component A to component B results in a harder foam, but generates more heat during the expansion phase of the foam. Decreasing the proportion of component A to component B normally results in a softer foam but with less heat generated. The ratio of component A to component B may be increased to substantially 3 to 2 on the upper range or decreased to substantially 3 to 7 on the lower range. During the expansion phase, the foam typically remains warm to the touch externally, but may reach temperatures as high as 300° fahrenheit internally. This level of heating is usually undesirable in many blasting applications due to the volatility of the explosives involved. In order to reduce the internal heat generated by the expanding foam, a freon component such as 141B may be added to the B component. It will be recognized that other freon mixtures such as R11, or other cooling agents with the same chemical cooling properties as freon, may be substituted without loss of generality. Typically, the B component contains a ratio of polyol resin to 141B freon of 3.33-1.67 to 1 in order to reduce the internal heat generated by the expanding foam during the expansion phase. Increasing the percentage of freon results in a cooler foam during the expansion phase, but the resulting foam is proportionally less dense. For a typical 7-inch diameter borehole, preferably 2.9 oz. of component A is combined with 7.5 oz. of component B, where the ratio of polyol resin to 141B freon is 2.0 to 1. Borehole diameters ranging from 2 to 24 inches may be accommodated by proportionally increasing or decreasing the amount of the foam components and pouch sizes as appropriate. To create a borehole decking plug with the preferred embodiment of the present invention, an operator forcefully squeezes the inner pouch 101 within the outer pouch 103, either by hand, foot, or some other means. The seal 105, joining the inner pouch 101 in a fixed position within the outer pouch 103, allows the operator to easily grasp the inner pouch 101 within the outer pouch 103, eliminating the problem of the inner pouch 101 sliding around within the outer pouch 103 making it difficult to grasp. Because the inner pouch 101 is typically constructed of thinner material than the outer pouch 103, the inner pouch 101 preferably bursts before the outer pouch 103, thus allowing component A 107 of the inner pouch 101 to combine with component B 109 within the outer pouch 103. The device is next typically turned inside out so that the inner pouch 101 and outer pouch 103 are contained within the external pouch 111. The operator then attaches a line to the tether attachment 115 of the external pouch 111, and preferably kneads the outer pouch 103 to mix the foam components. As component A and component B are preferably different colors and the outer pouch is typically made of a substantially clear flexible plastic, the operator may visually verify that the A and B components are properly mixed by observing the final color of the mixed components. Once the A and B components are mixed, the operator typically uses the line to lower the external pouch 111 containing the outer pouch 103 into the borehole to a preselected depth. The operator normally suspends the pouch from the line at the preselected depth until the foam expands and bursts the outer bag 103 but not the external pouch 111. The foam typically forms a decking plug with a positive seal by filling the external pouch and expanding upward to adhere to the walls of the borehole. The present invention is to be limited only in accordance with the scope of the appended claims, since others skilled in the art may devise other embodiments still within the limits of the claims.

A borehole decking plug which is created by a self-expanding plastic foam. Two closed waterproof pouches, an inner pouch and an outer pouch, each contain a separate component of the foam. The inner pouch is contained within the outer pouch, and both are contained within a third open external pouch having a tether attachment. Upon breaking the inner pouch, the separate foam components combine within the outer pouch to form a complete expansion foam. The foam expands slowly enough to provide sufficient time for the device to be lowered via the tether down a borehole to a preselected position. Once in position, the expansion foam bursts the outer pouch and escapes upward through the external pouch to form a deck plug at the preselected position.

This is a continuation-in-part of U.S. patent application Ser. No. 06/824,775, filed Jan. 31, 1987, now abandoned. FIELD OF THE INVENTION The present invention pertains to a respirator as an oxygen self-rescuer. BACKGROUND OF THE INVENTION Respirators of the type indicated above are housed in stand-by containers which can be closed airtight and are used, for example, by miners who carry them constantly on their bodies. The device is removed from the stand-by container for use. In a known respirator of the general type depicted here, the respirator bag is located above the chemical cartridge, and the cartridge is placed in the lower part of the housing; the respirator bag with its breathing hose and mouthpiece are located in the upper housing cover. The respirator, together with its stand-by container must be worn on the body by means of a shoulder strap. With such a breathing apparatus, (where the respirator bag is carried in front of the chest), the temperature increases during breathing because of the sensible heat of reaction from conversion of the contained oxygen-producing chemical. The management of the surface temperature of the chemical canister is vitally important for the reason that during the breathing transient, short-duration temperatures as high as 250° C. can be reached. The buildup of temperature between the back surface of the respirator and the abutting chest of the user of the device can cause inflammation and other skin irritations, which are a plainly unacceptable side effect. It almost goes without saying that such risks must be controlled in order that the user does not burn himself as a side effect. One solution to reducing this risk is described in Austrian Pat. No. 87,667, Sept. 15, 1921. British Pat. 1,170,702 to Drager, teaches a portable respiratory apparatus. The apparatus is worn on the back of a user and includes a chemical container that processes exhaled breath into oxygen, a breathing bag and an oxygen bottle. A second container situated between the first container and the user holds coolant which cools the first container. In addition there are tubes which extend down from the second container along the back of the user that allows the coolant to flow through to provide further cooling. The above mentioned components are supported and positioned in a carrying structure. Additionally, Drager teaches an apparatus that is used constantly over long periods of time rather than emergency situations that are short in comparison and is not collapsible to conveniently fit on the belt of the user and be worn until it is needed. Drager teaches the use of tubes to supply connection means that feed the coolant across the back of the user. The material around the tubes assists or increases the cooling effects from the coolant tubes. Unfortunately, if heat were present in the Drager apparatus, the material would increase the distribution of it. Accordingly, it is an object of the invention to provide a respirator device where the ambient temperature is reduced substantially between respirator surface and the chest of the carrier by means of a space-saving device. SUMMARY OF THE INVENTION The advantages achieved by this invention are specifically based on an optimum heat level obtaining between the respirator and the chest area. This is accomplished by the here disclosed configuration and positioning of a spacing body on the respirator bag surface. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective front view of the respirator in carrying position on a user to be protected. FIG. 2 is a perspective back view of the respirator with appended spacer body serving as an insulator against conduction of heat to the body of the carrier, and FIG. 3 is a perspective drawing of the space body of the present invention. According to the invention, what is claimed is a self-contained, personal breathing apparatus adapted for emergency use, including a canister, a supply of an oxygen-evolving chemical in the canister which is adapted to react with the carbon dioxide and water vapor in exhaled breath to generate oxygen, a flexible breathing bag having an input port and output port, and a mouthpiece connected to a breathing tube operably connected to the breathing bag, and a carrying strap to permit portability of the apparatus and which is further provided with: a pair of spaced apart loops that are horizontally aligned and affixed to a first vertical face of the apparatus; a means for physically spacing the apparatus from the chest of a user, further comprising an essentially flat first plate adapted to rest against the breathing bag; a pair of flanged protrusions oppositely affixed to the vertical edges of the first plate and being sized to removably engage with the loops; a second plate also having a substantially rectangular configuration and being adapted to rest against the chest of the user; a separation means disposed between the first and second plates to define a vertical passage between them; and, a pair of substantially parallel walls joining the vertical edges of the parallel plates to define a rectangular enclosure that is open at the upper and lower ends. DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, the apparatus, generally 10, is seen in a carrying position about the waist of a user 11. The breathing tube 12 (usually ribbed for durability) extends from the user's mouth (being retained by clenching a mouthpiece not seen behind the denture). The tube terminates at the upper surface of an integrated cover (not seen) for the internal chemical unit that is housed in a canister 9. The canister 9 is retained by an adjustable peripheral rigid clamp 13. The canister 9 is submerged in the flexible breathing bag 14, which has disposed on its outer surface 15 a one-way pressure relief valve 16. The apparatus 10 is held in place on the user 11 by strap 97 that wraps around the waist of the user 11 and strap 99 that wraps around the neck of the user 11. The strap 97 is attached to the breathing bag 14, with, for instance, a clamp or tie (not shown), as is well known in the art. Similarly, the two sides of the strap 99 is attached to the rectangular planar surface 21, by, for instance, glue or staple (not shown) as is well known in the art. As depicted in FIG. 2, disposed on the obverse face 17 of bag 14 is a rigid box-like structure, generally 18, which serves to insulate the chest of the user from exposure to the high sensible heat being generated by the respirator during operation, while maintaining the respirator properly disposed under the chin of the user and necessarily resting on the user's chest. A pair of spaced apart, fabric loops 19 (only the left one is seen), are vertically aligned on respirator face 17, being conventionally affixed thereto be sewing, or the like. An essentially rectangular planar surface 21 forms the outer side of spacer 18, which abuts the chest (not seen) of the user. The vertical dimension 22 of surface 21 exceeds the width dimension 23, so that the upper chest and throat area will be screened from exposure to the heat arising from the respirator. A parallel planar surface 24 is spaced apart from plate 21, thereby defining a vertical passage 35 between plates 21 and 24. These opposing surfaces are maintained firmly apart by vertical walls 25 and 26, which join the vertical edges of the two plates. To permit collapsibility of the spaced apart plates, the four vertical corners 27 C and R and 28C and R (seen in FIG. 3) are of a flexible, hingelike design when the respirator is out of use and to provide compactness during wearing. This hinge-like design can be for instance hinges 75 placed between the edges and corners that form the rigid box-like structure 18. The forward edges of ribs 34, 36 and 37 make locking contact with plate 21 by each edge having a piece of tape connecting it to plate 21. As the spacer is opened, the edges turn onto the plate and become flush with it, making locking contact. This is well known in the art. Appended intermediate to the length of vertical corner 27R is one of a pair of flanged protrusions 29 (the opposing member 31 extends from the other end and corner 28C is better seen in FIG. 3). The flange portions 32R and 32L are sized to loosely slip through loop 19, (on both sides), and to removably anchor to the chest of the user. The other important feature of the inventive spacer means will now be described in relation to FIG. 3. It will be seen that a separation means, generally 33, is disposed normal to and is interposed between parallel surfaces 21 and 24. A centrally located rib 34 is also hingeably connected at both its vertical edges 34C and 34R between the plates, as are end walls 25 and 26. Standing alone, they would bridge the surfaces but will normally maintain them in a collapsed position and abutting one another. As to material of construction, spaces mean 33 can be fabricated of a silicone polymer material. In order to assure that the vertical passages 35A, 35B, and 35C and 35D are open during respirator use, disposed on either side of central rib 34 are a pair of ribs 36 and 37. As for the offset ribs 36 and 37, these are differently configured with their backward edges 38 and 39, hingeably secured to chest-side surface 21, but having their forward edges 41 and 42 as free-standing. They are adapted to lock these members into vertical ridges 43 and 44, provided in the respirator-side surface 24 when the spacer means is to be in the operative stance. This is best seen in the broken out portion of surface 24. The resulting extended and locked ribs 36 and 37 will appear as shown in FIG. 3. This novel configuration permits positive locking apart of the opposing plates 21 and 24 without the use of adhesives permanently fixing in place the box-like structure 18, and also provides adequate strength from the 90° hinged axis to maintain the separation during use. Ribs 36 and 37 have another distinguishing feature in the outwardly taper upper edges 45 and 46, that interface between the chest surface 21 and the respirator surface 24. They extend above the upper edge 47 of the latter. These ribs thus provide more lateral support for the area of plate 21 which extends above horizontal edge 47. It is therefore made possible that the separation means 33, which is attached as described on the outside of the respirator 14, insures a snug fit for the breathing apparatus in the stand-by unit by simply folding it up when not required. It also has retractability in its working position, when the spacer is serving to function as an insulation means against heat transfer to the skin of the user.

The invention is a spacer of a respirator bag to be carried in front of the chest. Inside the respirator bag an oxygen producing chemical cartridge is positioned. On the outside of the respirator bag facing the body of the carrier, a spacer body open at its top and bottom, is positioned as a spacer between the carrier and respirator bag.

RELATED APPLICATION [0001] This application claims the benefit of U.S. Non Provisional application Ser. No. 13/554,546, filed Jul. 20, 2012, which claims the benefit of U.S. Provisional Application Ser. No. 61/511,298, filed Jul. 25, 2011, the disclosure of which are hereby incorporated in their entirety by reference. FIELD OF THE INVENTION [0002] The present invention relates to novel N-(imidazolidin-2-ylidene)quinoline derivatives, as alpha 2 adrenergic modulators. Alpha 2 adrenergic receptors have been characterized by molecular and pharmacological methods which include alpha 1A, alpha1B, alpha 2A, alpha 2B and alpha 2C. Activation of these alpha receptors evokes physiological responses. Adrenergic modulators described in this invention activate alpha 2 receptors and have useful therapeutic actions. BACKGROUND OF THE INVENTION [0003] Human adrenergic receptors are integral membrane proteins which have been classified into two broad classes, the alpha and the beta adrenergic receptors. Both types mediate the action of the peripheral sympathetic nervous system upon binding of catecholamines, norepinephrine and epinephrine. Norepinephrine is produced by adrenergic nerve endings, while epinephrine is produced by the adrenal medulla. The binding affinity of adrenergic receptors for these compounds forms one basis of the classification: alpha receptors tend to bind norepinephrine more strongly than epinephrine and much more strongly than the synthetic compound isoproterenol. The preferred binding affinity of these hormones is reversed for the beta receptors. In many tissues, the functional responses, such as smooth muscle contraction, induced by alpha receptor activation are opposed to responses induced by beta receptor binding. [0004] Subsequently, the functional distinction between alpha and beta receptors was further highlighted and refined by the pharmacological characterization of these receptors from various animal and tissue sources. Functional differences between α 1 and α 2 receptors have been recognized, and compounds which exhibit selective binding between these two subtypes have been developed. [0005] U.S. Pat. No. 6,723,741 discloses benzimidazoles and benzothiazoles as alpha 2 adrenergic receptor agonists. SUMMARY OF THE INVENTION [0006] The present invention relates to novel N-(imidazolidin-2-ylidene)quinoline derivatives, as alpha 2 adrenergic modulators. These novel compounds will be useful for the treatment of mammals, including humans, with a range of conditions and diseases that are alleviated by alpha 2A, 2B, 2C activation, including but not limited to treating glaucoma, elevated intraocular pressure, ischemic neuropathies, optic neuropathy, pain, visceral pain, corneal pain, headache pain, migraine, cancer pain, back pain, irritable bowel syndrome pain, muscle pain and pain associated with diabetic neuropathy, other retinal degenerative conditions, stroke, cognitive deficits, neuropsychiatric conditions, drug dependence and addiction, withdrawal symptoms, obsessive-compulsive disorders, obesity, insulin resistance, stress-related conditions, diarrhea, diuresis, nasal congestion, spasticity, attention deficit disorder, psychoses, anxiety, depression, autoimmune disease, Crohn's disease, gastritis, Alzheimer's, Parkinson's ALS, neurodegenerative diseases, retinal neuroprotection, skin conditions, skin diseases, rosacea, sunburn, psoriasis, acne rosacea, menopause-associated hot flashes, hot flashes resulting from orchiectomyatopic dermatitis, photoaging, seborrheic dermatitis, acne, allergic dermatitis, redness of the skin, treatment of redness and itch from insect bites, flushing and redness associated with hot flashes, erythema associated with hot flashes, telangiectasia (dilations of previously existing small blood vessels) of the face, rhinophymia (hypertrophy of the nose with follicular dilation), red bulbous nose, acne-like skin eruptions (may ooze or crust), burning or stinging sensation, irritated and bloodshot and watery eyes, erythema of the skin, cutenous hyperactivity with dilation of blood vessels of the skin, Lyell's syndrome, Stevens-Johnson syndrome, erythema multiforme minor, erythema multiforme major and or other inflammatory skin diseases, age related macular degeneration, wet macular degeneration, dry macular degeneration, geographic atrophy, diabetic retinopathy, diabetic macular edema, tumors, wound healing, inflammation and retinal vein occlusion, enhancing vision in patients with vision loss from conditions including glaucoma, retinitis pigmentosa and neuritis secondary to multiple sclerosis. [0007] In one aspect, the invention therefore provides a compound of Formula I, its enantiomers, diastereoisomers, hydrates, solvates, crystal forms and tautomers or a pharmaceutically acceptable salt thereof [0000] [0008] wherein: [0009] R 1 is hydrogen, substituted or unsubstituted C 1-8 alkyl or halogen; [0010] Y is CH or N; [0011] X is CH or N; and [0012] compound N-(imidazolidin-2-ylidene)quinolin-4-amine; [0013] except compound N-(4,5-dihydro-1H-imidazol-2-yl)-3-quinolinamine. [0014] In another aspect, the invention provides a compound of Formula I wherein: [0015] R 1 is hydrogen, methyl, bromine or chlorine; [0016] Y is CH or N; and [0017] X is CH or N; [0018] except compound N-(4,5-dihydro-1H-imidazol-2-yl)-3-quinolinamine. [0019] In another aspect, the invention provides a compound of Formula I wherein: [0020] R 1 is methyl, bromine or chlorine; [0021] Y is CH or N; and [0022] X is CH or N. [0023] In another aspect, the invention provides a compound of Formula I wherein: [0024] R 1 is methyl, bromine or chlorine; [0025] Y is CH or N; and [0026] X is CH or N. [0027] In another aspect, the invention provides a compound of Formula I wherein: [0028] R 1 is methyl; [0029] Y is CH or N; and [0030] X is CH or N. [0031] In another aspect, the invention provides a compound of Formula I wherein: [0032] R 1 is bromine; [0033] Y is CH or N; and [0034] X is CH or N. [0035] In another aspect, the invention provides a compound of Formula I wherein: [0036] R 1 is chlorine; [0037] Y is CH or N; and [0038] X is CH or N. [0039] In another aspect, the invention provides a compound of Formula I wherein: [0040] R 1 is chlorine; [0041] Y is CH or N; and [0042] X is CH. [0043] In another aspect, the invention provides a compound of Formula I wherein: [0044] R 1 is chlorine; [0045] Y is CH; and [0046] X is CH or N. [0047] The term “alkyl” as used herein, is defined as including a saturated monovalent hydrocarbon moiety having straight or branched moieties or combinations thereof and containing 1-8 carbon atoms, preferably 1-6 carbon atoms and more preferably 1-4 carbon atoms. Alkyl moieties can optionally be substituted by amino groups, halogens or one methylene (—CH 2 —) can be replaced by carbonyl, NH, carboxyl or by oxygen. [0048] The term “H” as used herein refers to a hydrogen atom. [0049] The term “O” as used herein refers to an oxygen atom. [0050] The term “N” as used herein refers to a nitrogen atom. [0051] The term “amino” as used herein refers to a group of formula —NH 2 . [0052] The term “halogen”, as used herein refers to an atom of chlorine, bromine, iodine or fluorine. [0053] The term “carbonyl” as used herein refers to a group of formula —C═O. [0054] The term “carboxyl”, as used herein refers to a group of formula —C(O)O—. [0055] Compounds of the invention are: N-(imidazolidin-2-ylidene)quinolin-4-amine; N-(imidazolidin-2-ylidene)-4-methylquinolin-3-amine; 4-Chloro-N-(imidazolidin-2-ylidene)quinolin-3-amine; 4-Bromo-N-(imidazolidin-2-ylidene)quinolin-3-amine; N-(imidazolidin-2-ylidene)pyrido[2,3-b]pyrazin-7-amine; N-(imidazolidin-2-ylidene)-8-methylpyrido[2,3-b]pyrazin-7-amine; 4-Chloro-N-(imidazolidin-2-ylidene)-1,5-naphthyridin-3-amine. [0063] Some compounds of Formula I and some of their intermediates have at least one stereogenic center in their structure. This stereogenic center may be present in an R or S configuration, said R and S notation is used in correspondence with the rules described in Pure Appli. Chem. (1976), 45, 11-13. [0064] As used herein, “tautomer” refers to the migration of protons between adjacent single and double bonds. The tautomerization process is reversible. Compounds described herein can undergo any possible tautomerization that is within the physical characteristics of the compound: [0000] [0065] The term “pharmaceutically acceptable salts” refers to salts or complexes that retain the desired biological activity of the above identified compounds and exhibit minimal or no undesired toxicological effects. The “pharmaceutically acceptable salts” according to the invention include therapeutically active, non-toxic base or acid salt forms, which the compounds of Formula I are able to form. [0066] The acid addition salt form of a compound of Formula I that occurs in its free form as a base can be obtained by treating the free base with an appropriate acid such as an inorganic acid, for example hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, nitric acid and the like; or an organic acid for example acetic acid, hydroxyacetic acid, propanoic acid, lactic acid, pyruvic acid, malonic acid, fumaric acid, maleic acid, oxalic acid, tartaric acid, succinic acid, malic acid, ascorbic acid, benzoic acid, tannic acid, pamoic acid, citric, methylsulfonic acid, ethanesulfonic acid, benzenesulfonic acid, formic and the like (Handbook of Pharmaceutical Salts, P. Heinrich Stahal & Camille G. Wermuth (Eds), Verlag Helvetica Chemica Acta-Zürich, 2002, 329-345). [0067] The invention also provides a pharmaceutical composition comprising a therapeutically effective amount of the compounds described above and pharmaceutically acceptable carriers, diluents, excipients. In the present invention a “therapeutically effective amount” is any amount of a compound which, when administered to a subject suffering from a disease against which the compounds are effective, causes reduction, remission, or regression of the disease. [0068] The pharmaceutical carrier can be a liquid and the pharmaceutical composition can be in the form of a solution. The pharmaceutically acceptable carrier can be a solid and the composition can be in the form of a powder, capsule or tablet. In a further embodiment, the pharmaceutical carrier can be a gel and the composition can be in the form of a suppository or cream. In a further embodiment the compound may be formulated as a part of a pharmaceutically acceptable transdermal patch. [0069] A solid carrier can include one or more substances which may also act as flavoring agents, lubricants, solubilizers, suspending agents, fillers, glidants, compression aids, binders or tablet-disintegrating agents; it can also be an encapsulating material. In powders, the carrier is a finely divided solid which is in admixture with the finely divided active ingredient. In tablets, the active ingredient is mixed with a carrier having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain up to 99% of the active ingredient. Suitable solid carriers include, for example, calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins. Liquid carriers are used in preparing solutions, suspensions, emulsions, syrups, elixirs and pressurized com-positions. The active ingredient can be dissolved or suspended in a pharmaceutically acceptable liquid carrier such as water, an organic solvent, a mixture of both or pharmaceutically acceptable oils or fats. The liquid carrier can contain other suitable pharmaceutical additives such as solubilizers, emulsifiers, buffers, preservatives, sweeteners, flavoring agents, suspending agents, thickening agents, colors, viscosity regulators, stabilizers or osmo-regulators. [0070] Suitable examples of liquid carriers for oral and parenteral administration include water (partially containing additives as above, e.g. cellulose derivatives, preferably sodium carboxymethyl cellulose solution), alcohols (including monohydric alcohols and polyhydric alcohols, e.g. glycols) and their derivatives, and oils (e.g. fractionated coconut oil and arachis oil). For parenteral administration, the carrier can also be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid carriers are useful in sterile liquid form compositions for parenteral administration. The liquid carrier for pressurized compositions can be halogenated hydrocarbon or other pharmaceutically acceptable propellent. [0071] Compounds of Formula I and their salts can be in the form of a solvate, which is included within the scope of the present invention. Such solvates include for example hydrates, alcoholates and the like. [0072] With respect to the present invention reference to a compound or compounds, is intended to encompass that compound in each of its possible isomeric forms and mixtures thereof unless the particular isomeric form is referred to specifically. [0073] Compounds according to the present invention may exist in different polymorphic forms. Although not explicitly indicated in the above formula, such forms are intended to be included within the scope of the present invention. [0074] The actual amount of the compound to be administered in any given case will be determined by a physician taking into account the relevant circumstances, such as the severity of the condition, the age and weight of the patient, the patient's general physical condition, the cause of the condition, and the route of administration. [0075] The patient will be administered the compound orally in any acceptable form, such as a tablet, liquid, capsule, powder and the like, or other routes may be desirable or necessary. Such other routes may include, without exception, transdermal, parenteral, subcutaneous, intranasal, via an implant stent, intrathecal, intravitreal, topical to the eye, back of the eye, front of the eye, intramuscular, intravenous, and intrarectal modes of delivery. Additionally, the formulations may be designed to delay release of the active compound over a given period of time, or to carefully control the amount of drug released at a given time during the course of therapy. [0076] In another aspect the invention relates to a method for treating a condition alleviated by alpha 2A, 2B, 2C activation, in a patient in need thereof which comprises administering a pharmaceutical composition comprising a therapeutically effective amount of compound of Formula I or a pharmaceutically acceptable salt thereof. [0077] In another embodiment of the invention, there are provided pharmaceutical compositions including at least one compound of the invention in a pharmaceutically acceptable carrier thereof. The phrase “pharmaceutically acceptable” means the carrier, diluent or excipient must be compatible with the other ingredients of the formulation and not deleterious to the recipient thereof. [0078] In another embodiment of the invention, there is provided an article of manufacture comprising packaging material and a pharmaceutical agent contained within said packaging material, wherein the pharmaceutical agent is therapeutically effective and wherein the packaging material comprises a label which indicates the pharmaceutical agent can be used for treating a disorder associated with the alpha 2 receptors and wherein said pharmaceutical agent comprises an effective amount of at least one compound of Formula I. [0079] Since individual subjects may present a wide variation in severity of symptoms and each drug has its unique therapeutic characteristics, the precise mode of administration and dosage employed for each subject is left to the discretion of the practitioner. [0080] The synthetic scheme set forth below, illustrates how compounds according to the invention can be made. Those skilled in the art will be able to routinely modify and/or adapt the following scheme to synthesize any compounds of the invention covered by Formula I. [0000] [0081] The synthesis of compounds of Formula I was started with the pyridine-3-amine derivative, which treated with thiophosgene (CSCl 2 ) in the presence of triethylamine (Et 3 N) in tetrahydrofuran gave the isothiocyanate key intermediate. The isothiocyanate was then reacted with ethane-1,2-diamine followed by mercury oxide treatment in methanol and afforded the desired compound of Formula I. DETAILED DESCRIPTION OF THE INVENTION [0082] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention claimed. As used herein, the use of the singular includes the plural unless specifically stated otherwise. [0083] It will be readily apparent to those skilled in the art that some of the compounds of the invention may contain one or more asymmetric centers, such that the compounds may exist in enantiomeric as well as in diastereomeric forms. Unless it is specifically noted otherwise, the scope of the present invention includes all enantiomers, diastereomers and racemic mixtures. Some of the compounds of the invention may form salts with pharmaceutically acceptable acids or bases, and such pharmaceutically acceptable salts of the compounds described herein are also within the scope of the invention. [0084] The present invention includes all pharmaceutically acceptable isotopically enriched compounds. Any compound of the invention may contain one or more isotopic atoms enriched or different than the natural ratio such as deuterium 2 H (or D) in place of protium 1 H (or H) or use of 13 C enriched material in place of 12 C and the like. Similar substitutions can be employed for N, O and S. The use of isotopes may assist in analytical as well as therapeutic aspects of the invention. For example, use of deuterium may increase the in vivo half-life by altering the metabolism (rate) of the compounds of the invention. These compounds can be prepared in accord with the preparations described by use of isotopically enriched reagents. [0085] The following examples are for illustrative purposes only and are not intended, nor should they be construed as limiting the invention in any manner. Those skilled in the art will appreciate that variations and modifications of the following examples can be made without exceeding the spirit or scope of the invention. [0086] The IUPAC names of the compounds mentioned in the examples were generated with ACD version 12.5. [0087] Unless specified otherwise in the examples, characterization of the compounds is performed according to the following methods: [0088] NMR spectra are recorded on 300 MHz Varian and acquired at room temperature. Chemical shifts are given in ppm referenced either to internal TMS or to the residual solvent signal. [0089] All the reagents, solvents, catalysts for which the synthesis is not described are purchased from chemical vendors such as Sigma Aldrich, Fluka, Lancaster, however some known reaction intermediates, for which the CAS registry number is mentioned, were prepared in-house following known procedures. [0090] Usually the compounds of the invention were purified by flash column chromatography. [0091] The following abbreviations are used in the examples: [0092] DCM dichloromethane [0093] EtOH ethanol [0094] MeOH methanol [0095] NH 3 ammonia [0096] EtOAc ethylacetate [0097] TEA triethylamine [0098] CSCl 2 thiophosgene [0099] THF tetrahydrofuran Example 1 Intermediate 1 1-(2-Aminoethyl)-3-(quinolin-4-yl)thiourea [0100] [0101] To a solution of ethane-1,2-diamine (CAS 107-15-3) (704 mg, 4.5 eq) in benzene (10 mL) was added a solution of 4-isothiocyanato-quinoline (CAS 868163-42-2) (480 mg, 2.61 mmol) in benzene (5 mL). The resulting mixture was stirred at room temperature for 16 h. The product precipitated as a pale yellow solid, which was filtered to collect the solid washed with ether and gave Intermediate 1. Example 2 Intermediate 2 4-Chloro-3-isothiocyanato-1,5-naphthyridine [0102] [0103] To a solution of 4-chloro-1,5-naphthyridin-3-amine (CAS 930276-73-6) (550 g, 3.07 mmol) in THF (10 mL) was added TEA (0.95 mL, 6.76 mmol) followed by CSCl 2 (0.26 mL, 3.4 mmol) at 0° C. The mixture was stirred at room temperature for 2 h. Celite (2 g) was added to the reaction mixture, then concentrated and purified by silica gel column chromatography using hexane:EtOAc (7:3) and gave Intermediate 2 (360 mg). Example 3 Intermediate 3 1-(2-Aminoethyl)-3-(4-chloro-1,5-naphthyridin-3-yl)thiourea [0104] [0105] To a solution of ethane-1,2-diamine (CAS 107-15-3) (0.54 mL, 8.12 mmol) in benzene (10 mL) was added a solution of Intermediate 2 (360 mg) in benzene (5 mL). The resulting mixture was stirred at room temperature for 16 h. Benzene and excess of ethane-1,2-diamine were decanted. The product was washed with ethyl-ether and yielded Intermediate 3. Example 4 Compound 1 N-(imidazolidin-2-ylidene)quinolin-4-amine [0106] [0107] Intermediate 1 was taken in EtOH (15 mL) with mercury oxide (618 mg) and heated at reflux temperature for 4 h. The mixture was cooled to room temperature and filtered through celite. Silica gel was added to the filtrate and concentrated and purified by chromatography on silica gel with 5% NH 3 -MeOH:DCM and gave (68 mg) Compound 1 as a white solid. [0108] 1 H NMR (Methanol-d 6 ) δ: 8.54 (d, J=5.0 Hz, 1H), 8.23 (d, J=7.9 Hz, 1H), 7.88 (d, J=8.5 Hz, 1H), 7.61-7.72 (m, 1H), 7.41-7.53 (m, 1H), 7.05 (d, J=5.3 Hz, 1H), 3.56 (s, 4H). Example 5 Compound 2 4-Chloro-N-(imidazolidin-2-ylidene)-1,5-naphthyridin-3-amine [0109] [0110] Intermediate 3 was taken in EtOH (15 mL) with mercury oxide (422 mg) and heated at reflux temperature for 2 h. The mixture was cooled to room temperature filtered through celite. Silica gel was added to the filtrate concentrated and purified by silica gel chromatography using 5% NH 3 -MeOH:DCM and gave (120 mg) Compound 2. [0111] 1 H NMR (Methanol-d 4 ) δ: 8.90 (dd, J=4.1, 1.5 Hz, 5H), 8.68 (s, 1H), 8.36 (dd, J=8.2, 1.5 Hz, 1H), 7.66 (dd, J=8.5, 4.4 Hz, 1H), 3.56 (s, 4H). [0112] Compounds 3, 4, 5, 6 and 7 were prepared in a similar manner to the method described in Example 5 for Compound 2 starting with the corresponding starting material. The results are tabulated below in Table 1. [0000] TABLE 1 Compound IUPAC name 1 NMR (Solvent; δ ppm) 3 1 H-NMR (Methanol-d 4 ) δ: 8.46 (s, 1H), 8.02-8.09 (m, 1H), 7.89-7.98 (m, 1H), 7.51-7.67 (m, 2H), 3.52 (s, 4H), 2.56 (s, 3H) 4 1 H NMR (Methanol-d 4 ) δ: 8.55 (s, 1H), 8.14-8.22 (m, 1H), 7.92-8.00 (m, 1H), 7.57-7.68 (m, 2H), 3.52 (s, 4H) 5 1 H NMR (Methanol-d 4 ) δ: 8.49 (s, 1H), 8.16-8.23 (m, 1H), 7.92-7.99 (m, 1H), 7.60-7.68 (m, 2H), 3.52 (s, 4H) 6 1 H NMR (Methanol-d 4 ) δ: 8.76- 8.85 (m, 3H), 7.88 (d, J = 2.6 Hz, 1H), 3.59 (s, 4H) 7 1 H NMR (Methanol-d 4 ) δ: 8.90 (d, J = 1.8 Hz, 4H), 8.85 (d, J = 1.8 Hz, 1H), 8.73 (s, 1H), 3.53 (s, 4H), 2.64 (s, 3H) [0113] The following assay was used to demonstrate the potency and selectivity of the compounds according to the invention. Example 6 RSAT Compound Screening [0114] Novel compounds were synthesized and tested for alpha adrenergic activity using the Receptor Selection and Amplification Technology (RSAT) assay (Messier et. al., 1995, Pharmacol. Toxicol. 76, pp. 308-311). Cells expressing each of the alpha2 adrenergic receptors alone were incubated with the various compounds and a receptor-mediated growth response was measured. The compound's activity was expressed as its relative efficacy compared to a standard full agonist (see Table 2). The compounds of this invention activate alpha 2 receptors. [0000] TABLE 2 Biological Data: Intrinsic Activity EC 50 nM (efficacy) Compound number IUPAC name Alpha 2C 1 N-(imidazolidin-2-ylidene)quinolin-4- 17.4 amine (0.95) 2 4-Chloro-N-(imidazolidin-2-ylidene)-1,5- 21 naphthyridin-3-amine (0.95) 3 N-(imidazolidin-2-ylidene)-4- 1653 methylquinolin-3-amine (0.21) 4 4-Chloro-N-(imidazolidin-2- 368 ylidene)quinolin-3-amine (0.66) 5 4-Bromo-N-(imidazolidin-2- 1529 ylidene)quinolin-3-amine (0.17) 6 N-(imidazolidin-2-ylidene)pyrido[2,3- 4581 b]pyrazin-7-amine (0.44) 7 N-(imidazolidin-2-ylidene)-8- 311 methylpyrido[2,3-b]pyrazin-7-amine (0.93)

The present invention relates to novel N-(imidazolidin-2-ylidene)quinoline derivatives, processes for preparing them, pharmaceutical compositions containing them and their use as pharmaceuticals.

FIELD OF THE INVENTION This invention relates to outdoor electrical boxes, and particularly, to an improved electrical cover that can mount over a standard electrical box and provide a rain tight enclosure for a wide range of standard electrical devices. BACKGROUND OF THE INVENTION Outdoor electrical outlets are commonly used to provide electrical service near gardens, swimming pools, patios and the like. Some of those used outdoors have a weatherproof enclosure for covering the outlets which may be thermostats, timers for watering systems, switches, and similar electrical devices. These outdoor enclosures are commonly referred to in the industry as FS or field service boxes. Presently, popular forms of outlet covers for providing covers to existing electrical outlets requires that the installer purchase special mounting plates, manufactured specifically for that particular box, to configure the enclosure for the particular type of electrical service that is required. As many as approximately 50 different plates may be manufactured to provide for all the different types of electrical services that may be required in typical outdoor wiring applications. The requirement to provide a special plates increases the expense of the device and also requires the electrical distributor to increase inventory in order to stock all of the special plates. The first advantage of this invention is that one configuration of the enclosure of this invention will accommodate a range of outdoor electrical devices whereas standard covers commonly used in the trade require a vast range of configurations to provide the same functionality. A second advantage is that special electrical devices and mounting plates are not required. Standard electrical devices and standard face plates that are pre-existing with the electrical outlet are re-used. SUMMARY OF THE INVENTION This invention consists of an electrical enclosure that is used outdoors in conjunction with an existing standard electrical enclosure, either flush or surface mounted. The rear surface of the enclosure has an integral adapter plate that mates with the existing standard electrical box and creates a rain tight fit when a gasket is sandwiched between the two. The integral adapter plate is designed to accommodate a wide variety of standard electrical devices including common receptacles, twist lock plug receptacles, ground fault interrupt receptacles, switches, timers, and thermostats. The pre-existing plate is then used to seal the open area around the device mounted on the adapter plate. Special electrical covers for different boxes are therefore not required with the installation since the pre-existing devices and plates that are removed from the existing flush or surface mounted box may be re-used with the enclosure of this invention. OBJECTS AND ADVANTAGES The first object of this invention to provide a simple electrical box cover that may be installed outdoors over an existing junction box, either flush or surface mounted, to provide an enclosure for standard electrical devices and their plates. A second object of the invention is to provide a universal box in one configuration that will accommodate a wide range of standard electrical devices and their plates. The invention eliminates the need for special devices and plates or multiple boxes having different configurations. A third object of the invention is to provide a rain tight enclosure for mounting pre-existing electrical devices and plates. An integral adapter plate at the rear of the adapter box provides a rain tight fit when connected to the pre-existing junction box with a gasket sandwiched therebetween. Other objects and advantages of the present invention will be better understood from the following description when read in conjunction with the appropriate drawings. DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of the universal electrical box cover of the present invention together with pre-existing standard electrical components that are commonly used in conjunction with it. FIG. 2 is a cross-sectional view of the universal electrical box including a pre-existing standard receptacle and a pre-existing standard receptacle plate. FIG. 3 is a frontal view of the universal electrical cover including an integral adapter plate located at the back of the dry box. FIG. 4 is a perspective view of the universal electrical box cover including the integral adapter plate and front cover member pivoted to its upward or open position. DESCRIPTION OF THE INVENTION The invention is a universal electrical box cover that may be used outdoors in conjunction with a pre-existing standard outlet box either flush or surface mounted to a wall. Three separate parts; the open front enclosure having an integral adapter plate, the gasket, and the front cover member are interconnected to comprise the cover. FIG. 4 is a perspective view of the universal electrical box cover 10 except for the gasket but including the open front enclosure 12 with the integral adapter plate 14, and the front cover member 16. Pins 18 connect front cover member 16 pivotally to the open front enclosure 12 at its upper end. The universal electrical box cover is used in conjunction with a pre-existing standard outlet box 20, a pre-existing standard electrical receptacle 22, and a pre-existing standard receptacle plate 24 as shown in FIG. 1. The standard outlet box 20 is typically an existing box that is either flush or surface mounted in an outdoor location. The pre-existing standard electrical receptacle 22 and pre-existing standard receptacle plate or cover 24 may be unfastened from the existing outdoor box and reused with the universal electrical cover of this invention. After the electrical power has been cut off, the electrical connections to the standard receptacle 22 need not be broken, as the receptacle may be unscrewed from the pre-existing outlet box 20 and pulled through the window or opening 27 in the gasket and the window or opening 28 in the adapter plate 14. The gasket 26 and the open front enclosure 12 are aligned with the pre-existing standard outlet box 20. The screws 21 that had previously held the receptacle to the outlet box 20 are then re-inserted through the ears of the standard receptacle 22, through the matching holes 23 in the integral adapter plate 14, and through the matching holes 25 in the gasket 26. The outer periphery of adapter plate or back plate 14 has both a front surface as shown in FIG. 1 and a back surface on the opposite side thereof. The screws 21 fasten into same threaded holes 19 in the pre-existing outlet box 20 that were previously used for fastening the receptacle. The screws 21 that are used to fasten the universal electrical cover to the existing outlet box are usually the same screws that were previously used to hold the receptacle to the outlet box. As seen in FIG. 1 the pre-existing outlet box 20 has the threaded or screw receiving holes 19 in the front face thereof. After the standard receptacle 22 is fastened securely to the pre-existing outlet box 20, holding the open front enclosure 12 and gasket 26 firmly in place, the pre-existing standard receptacle plate 24 is fastened to the receptacle in the usual manner using the pre-existing screw 31 through the pre-existing receptacle plate threaded hole 33. Although pictured separate of the enclosure 12, the front cover member 16 is pinned to the open front enclosure 12 when manufactured. As seen in FIGS. 1 to 4 the pins 18 have an enlarged head and are placed through holes 46 in cover member 16 and forced into holes 48 in enclosure 12 which have bosses 50 to accommodate the pins. The holes 46 are oversized so the cover member 16 is free to pivot. The enclosure 12 has four side walls, 60, 61, 62, and 63, which enclose a chamber 64. The gasket is preferably made of closed cell weather resistant resilient foam and is substantially planar and of a size to overlay a substantial portion of the outside rear of the integral back plate 14. The cover member 16 is simply rotated to its open position when connecting the open front enclosure 12 to the existing outlet box as previously described. A lip 30 is provided on the outer surface of the enclosure 12 at the lower end to provide a device for holding the cover member 16 in the closed position. Cover member 16 is constructed of plastic and a slotted tab (not shown in FIG. 1) on the cover mates with lip 30 which forces the tab outward. When the slot clears the lip 30 the lip snaps into the slot within the tab. After the standard electrical receptacle 22 and standard plate 24 are fastened in the universal electrical cover as mentioned above and the cover member 16 is rotated to its closed position, the universal electrical cover is a rain tight enclosure that provides weather protection to the electrical devices enclosed within. The electrical devices could be any type of electrical service commonly used outdoors, including electrical receptacles, duplex receptacles, twist-lock receptacles, ground fault interrupt receptacles, switches, timers, etc. As shown in FIG. 3, in addition to holes 23 previously mentioned, several additional holes 38 are provided in the integral adapter plate 14 for connecting any of the various electrical devices that are commonly used in outdoor applications. Likewise, the gasket 26 has similar holes that align with the holes in adapter plate 14 as well with the window 27 and the outer periphery of the gasket 26 being coextensive with the window 28 and outer periphery of the adapter plate 14. As shown in FIG. 4, the front cover member 16 has cord exit holes 32 cut in the bottom surface 42 to allow for the exit of electrical cords (not shown) that may be connected to a receptacle within the enclosure 12. The electrical cords, with the cover member 16 closed, may therefore be kept dry while plugged in. The cover member 16 has a locking hole 34 which mates with a locking hole 36 in the enclosure 12 to provide a means for locking the cover member to the enclosure. With the cover member 16 closed against the enclosure 12, the hasp of a padlock is simply slipped through the mating holes. As shown in FIG. 4, a feature which provides rain tightness is the cavernous cover member 16 of the universal electrical cover 10. The cavernous cover member 16 provides ample space for the outward projection of thick cords that may be plugged into the receptacle within the cover. FIG. 4 also shows the tab 40 on cover member 16 that mates with the lip 30 on the enclosure. Tab 40 has a slot 44 within it which the lip 30 of the dry box slips through to provide a locking feature for the cover. FIG. 2 shows a cross sectional view of the universal electrical cover 10 of this invention including the enclosure 12, gasket 26, and cover member 16. The universal electrical cover 10 is shown fastened in place to a pre-existing outlet box 20 with a pre-existing standard electrical receptacle 22 and a pre-existing standard receptacle plate 24 enclosed within. Although there has been shown and described an example of what is at present considered the preferred embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appended claims.

A rain tight universal electrical box cover that will attach to most pre-existing, standard sized, flush or surface mounted electrical boxes and convert it into a rain tight outdoor electrical enclosure. The box cover accepts pre-existing standard electrical devices such as receptacles, switches, timers, and other similar devices and their pre-existing cover plates thereby eliminating the need to provide special provisions or numerous designs to accommodate the variety of electrical devices as is required with many of the popular electrical box covers that are commonly used in the industry today.

CLAIMS OF PRIORITY [0001] This application claims priority to and is a continuation of U.S. patent application Ser. No. 14/197,680, filed Mar. 5, 2014, to be issued as U.S. Pat. No. 9,455,974, the disclosure of which is fully incorporated into this document. BACKGROUND [0002] Many authentication methods and other security mechanisms are available to protect online accounts against unauthorized access. In general, all such methods require a compromise between ease of access to the account by the owner and strength of security against access by an attacker. For example, a simple password may permit a user to quickly and easily access an account. In contrast, a security mechanism that requires the combination of a password plus a one-time personal identification code is not as easy for the account's user, but it is considerably harder for an attacker to breach than the simple password option. [0003] Determining an appropriate authentication method to use for a particular account can be challenging. Using methods that are too onerous may lock legitimate users out of their accounts, while using methods that are too lax may allow attackers in. [0004] Accordingly, the inventors have determined that there is a need to identify methods that more effectively balance the trade-off between effective security and ease of use. SUMMARY [0005] In various embodiments, a system including one or more processors and one or more data storage facilities implements a method of assigning a value to an account that is associated with data maintained at the data storage facilities. The data is made of various data elements, and the system automatically identifies a set of signals in the data elements. For each of the signals, the system determines a signal value based on metadata with the data element or by any suitable process. The system assigns weights to at least a subset of the signal values to yield a set of weighted signal values. The system then uses the set of weighted signal values to assign an account value to the account. Based on the account value, the system may select a security mechanism or a storage-related action that corresponds to the account value, and it may instruct the data storage facilities to implement the selected security related action or storage related action. [0006] In an embodiment, the data elements may include two or more of the following data types: actual user data, metadata descriptive of the actual user data, user profile data, or measured usage parameters. [0007] In some embodiments, the signals may include one or more of the following characteristics of the account: an age of the account, a frequency of use of the account, contact information associated with the account, a reputation of the account, an amount of data stored or associated with the account, an ability of the account to access other accounts, an ability of the account to access or use financial instruments, or a type of data in the account; [0008] Examples of the security-related actions may include enabling a stronger password or authentication sequence for the account, enabling one or more security precautions relating to account recovery mechanisms, enabling per-transaction authentication for the account, adjusting thresholds for detecting fraudulent attempts to access the account, triggering alerts for manual review of an account login, or adjusting thresholds for requiring per-transaction authentication. Examples of the storage-related actions may include increasing an available storage capacity for the account, or adding an automatic data backup process to the account. [0009] In some embodiments, when assigning the weights to at least a subset of the signal values to yield the set of weighted signal values, the system may use the signal values for a first one or more of the signals to determine a weighted signal value for a second one of the signals. It may then determine the weighted signal value for the second signal as a product of the determined weight and the signal value of the second signal. [0010] Optionally, when using the set of weighted signal values to assign the account value to the account, at least one of the signals may be a binary signal that can have only a first value or a second value (such that the first value signifies a high value account). If so, then the system may determine that the binary signal has a signal value that equals the first value, and if so it may assign a known high quantitative value as the account value. [0011] In some embodiments, the system may present indicia of the assigned account value to the user, receive user feedback relating to the assigned account value, use the feedback to adjust one or more of the weights, use the adjusted one or more weights to update the set of weighted signal values, and use the updated set of weighted signal values to update the account value. [0012] Optionally, a first group of the signals may include any of the following: an age of the account, a frequency of use of the account by the user, or an amount of data associated with the account. If so, then when assigning the weights to the signal values for each signal in the first group the system may: determine whether the signal value of the signal exceeds a threshold; convert the signal value to a quantitative value based on whether or not it exceeds the threshold; and multiply the quantitative value for the signal by a weight that corresponds to the signal to yield the weighted signal value for the signal. Alternatively, a first group of the signals may include any of the following: an ability of the account to access a different account; or an ability of the account to access a financial instrument. If so, then when using the set of weighted signal values to assign an account value to the account, if at least one of the signals in the first group is present, the system may automatically assign a known high value as the account value. [0013] As another alternative, at least one of the signals may include a measured value of contact information for the user. If so, then the system may determine the measured value of contact information based on at least one of the following: a number of entities who are contacts that the user has in a contacts database; or a number of entities who are contacts of entities who are also contacts of the user. As yet another alternative, at least one of the signals may include a measured value of reputation for the user. If so, then the system may determine the measured value of reputation based on at least one of the following: a measurement of external sources that point to published information relating to the account; a measurement of a level of interactions that involve the user's account, where the interactions are those that are between the user and contacts of the user; or a measurement of a level of external communication directed from the account. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 is a flowchart illustrating a process of determining a value of an account. [0015] FIG. 2 is a diagram illustrating an example of signals that may be received by a weighting module and scoring module of an account valuation system. [0016] FIG. 3 is a block diagram showing elements of computing systems that may be used to implement various embodiments described in this document. DETAILED DESCRIPTION [0017] As used in this document, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. As used in this document, the term “comprising” means “including, but not limited to.” [0018] In this document, a “computing device” refers to a device that includes a processor and non-transitory, computer-readable memory. The memory may contain programming instructions that, when executed by the processor, cause the computing device to perform one or more operations according to the programming instructions. As used in this description, a computing device may be a single device, or any number of devices having one or more processors that communicate with each other and share data and/or instructions. [0019] As used in this document, an “account” means an online set of data that is stored in a data storage facility and associated with a user. Examples of accounts include those for e-mail services, photo storage services, document storage or backup services, social media services, audio and/or video media sharing services, and other online services. To access the data of an account, the user must perform an action that is required by a security mechanism that uses the action to authenticate the user to a device, system, application or data set. Examples of security mechanisms include prompts that require a user to present a token, enter or speak a passcode, provide a biometric identifier, perform a known sequence of steps, or take other actions. The system can then compare the user's response to a set of known responses identify whether the user is authorized to access the device, system, application or data set. [0020] Online accounts are valuable, both to their owners and to online attackers who may attempt to hijack the accounts. Email accounts, photo collection accounts, online data backup accounts, online financial accounts and other accounts all have intrinsic value because of the often-personal data that may be stored with the account, the ability of the account to communicate with or obtain information from external resources, or other features. However, not all accounts may have the same value to a user or potential hijacker. [0021] The inventors have determined that a value of an account may depend on factors such as the type of data stored in or associated with the account, the amount of data stored in or associated with the account, capabilities of the account, or measured usage characteristics of the account. For example, a free webmail account is worth very little immediately after it is acquired. However, the account will gain value as it is used. Over time and through usage, a webmail account may gain contacts, communications history, other data and reputation. One account also may become a gateway to other valuable accounts, such as if it is used as an account recovery mechanism for those other accounts. The value of an account accrues to the account's owner, but an attacker also may consider the account to have value if the attacker is able to compromise the account. [0022] This document describes a method and system for determining a value of an account, as well as for using that value to take a security-related action by determining an appropriate security mechanism to protect the account. As an alternative, the system may use the value to take a storage related action that helps to back up and/or otherwise protect data associated with the account. [0023] FIG. 1 is a flowchart describing various steps that a system may implement to determine a value and a security mechanism for an account. The system will maintain an account at one or more data storage facilities (step 101 ). A data storage facility is a set of one or more non-transitory computer-readable media on which data associated with the account is stored. The account may be stored on a single storage facility or distributed across multiple facilities. In addition, some data elements may be separated from other data elements based on a type of data element. For example, actual user data (such as messages, photos, or document files) may be stored in one facility, metadata that is descriptive of the user data (such as file type, date created, or intended use) may be stored in another facility, user profile data may be stored in another location, and measured usage parameters (such as a frequency of access and/or updating) may be stored in another facility. [0024] The method determines the account value by automatically identifying and quantifying various characteristics of the account, which may be referred to as “signals” (step 103 ). Each signal is assigned either a binary value or a score. The system determines a value of each signal (step 105 ) and weights each signal according to various criteria (step 107 ). Weights are numerical factors by which each signal value may be multiplied or otherwise adjusted. The system may then use the weighted signals as inputs of an algorithm to calculate a numeric account value for the account (step 109 ). [0025] Signals may include, for example: (i) an age of the account; (ii) a frequency of use of the account (such as logins per time period, actions taken by the user per time period, a number of messages sent from the account or files uploaded to the account in a time period, etc.); (iii) contact information associated with the account (such as pointers to other accounts associated with friends or contacts of the account owner); (iv) reputation of the account (e.g., that of the owner, or of contacts in the case of social networking providers with contact lists for friends); (v) an amount of data stored or associated with the account (e.g., e-mail, file uploads, pictures, etc.); (vi) an ability of the account to access other accounts (e.g., password reset communications from other service providers may be sent to this account); (vii) an ability of the account to access or use financial instruments (e.g., an ability to make payments, an ability to transfer money, etc.); or (viii) a type of data in the account (e.g., personal financial records, personal health records, corporate sales records, etc.). [0026] The system may automatically calculate the value of each signal (step 105 ) by analyzing characteristics of the signals as found in the account's data elements as stored in a data storage facility. The characteristics may be found in account aspects such as metadata for the account, measured data relating to account usage or authorization levels, or an assessment of actual data in the account. For example, the value of a signal representing an amount of data may be a measured value of the data, while the value of a type of data may be determined by assigning certain types of data (such as personal financial or health data) higher values than other types of data (such a person's music library or data that a user has shared on a public website). [0027] FIG. 2 illustrates examples of a process by which a weighting module 220 of the system may assign or receive values for various types of signals. As shown, the signals may include any or all of the following: an age of the account 201 ; a frequency of use of the account 203 ; contact information associated with the account 205 ; reputation of the account 207 ; an amount of data stored or associated with the account 209 ; an ability of the account to access other accounts 211 ; an ability of the account to access or use financial instruments 213 ; or other signals. After the weighting module assigns weights to any or all of the signals, an account value scoring module 230 may then use the weighted signal values to determine a value to assign to the account. [0028] Returning to FIG. 1 , in some embodiments the algorithm used in the weighting process (step 107 ) may be dynamic, in that the system may use the value of one signal (or the values of a first set of signals) to determine how much (or how little) to weight another signal. As an example, a first signal relating to an age of the account may be used to determine how much weight to apply to a signal based on frequency of use such that the frequency signal is given greater weight (and this value) on an older account. Thus, the weight applied to the second signal should be increased as the value of the first signal increases. Some characteristics may be binary, meaning that if the characteristic is present the system will automatically consider the account to be a high value account. Other characteristics may be represented by quantitative values. In addition, the system may present the user with various queries, and it may use the responses to determine how to weight various signals. [0029] Optionally, the system may determine a preliminary account value and present the preliminary account value (or something representing the value) to the account's user to solicit feedback (step 111 ). Examples of indicia that may represent the account value include a proxy indicator, a word or phrase representing the value, or other indicia that may be more user-friendly than a raw number. The system may then set or adjust the final value or any weighting factor based on the user's feedback. [0030] The system may use the value to determine a security-related action that the user or the account's service provider may take (step 113 ), such as: (i) recommending that the user enable a stronger password or authentication sequence (such as multi-factor authentication) for the account; (ii) recommending that the user take other security precautions for the account, such as to enable account recovery mechanisms or per-transaction authentication; (iii) adjusting thresholds for detecting fraudulent attempts to access the account; (iv) triggering alerts for manual review of an account login; or (v) adjusting thresholds for requiring per-transaction authentication. It may then present the security mechanism to a user (step 115 ), such as by presenting it to the account's user for feedback, presenting it to an account custodian or service provider for implementation, or to the account system itself for implementation. [0031] In addition or alternatively, the system may use the value to determine a storage-related action that the user or the account's service provider may take (step 117 ), such as: (i) recommending that the user increase an available storage capacity for the account; (ii) recommending that the user add an automatic data backup process to the account; or (iii) automatically taking either of the actions listed above. It may then present the storage-related action to a user (step 119 ), such as by presenting it to the account's user for feedback, presenting it to an account custodian or service provider for implementation, or to the account system itself for implementation. [0032] Optionally, the value of an account may increase or decrease over time. The system may periodically determine an updated value, or it may do so upon a user request, or it may do so automatically based on certain criteria being satisfied. [0033] FIG. 3 depicts an example of internal hardware that may be used to contain or implement the various computer processes and systems as discussed above. An electrical bus 300 serves as an information highway interconnecting the other illustrated components of the hardware. CPU 305 is a central processing unit of the system, performing calculations and logic operations required to execute a program. CPU 305 , alone or in conjunction with one or more of the other elements disclosed in FIG. 3 , is a processing device, computing device or processor as such terms are used within this disclosure. When this disclosure or any claim uses the term “processor,” unless specifically stated otherwise it may include a single processor, or multiple processors that distributed within a system or among multiple systems in a way such a together they perform all steps of a defined method. Read only memory (ROM) 310 and random access memory (RAM) 315 constitute examples of memory devices. [0034] A controller 320 interfaces with one or more optional memory devices 325 that service as data storage facilities to the system bus 300 . These memory devices 325 may include, for example, an external DVD drive or CD ROM drive, a hard drive, flash memory, a USB drive or another type of device that serves as a data storage facility. As indicated previously, these various drives and controllers are optional devices. Additionally, the memory devices 325 may be configured to include individual files for storing any software modules or instructions, auxiliary data, incident data, common files for storing groups of contingency tables and/or regression models, or one or more databases for storing the information as discussed above. [0035] Program instructions, software or interactive modules for performing any of the functional steps associated with the processes as described above may be stored in the ROM 310 and/or the RAM 315 . Optionally, the program instructions may be stored on a tangible computer readable medium such as a compact disk, a digital disk, flash memory, a memory card, a USB drive, an optical disc storage medium, a distributed computer storage platform such as a cloud-based architecture, and/or other recording medium. [0036] A display interface 330 may permit information from the bus 300 to be displayed on the display 335 in audio, visual, graphic or alphanumeric format. Communication with external devices may occur using various communication ports 340 . A communication port 340 may be attached to a communications network, such as the Internet, a local area network or a cellular telephone data network. [0037] The hardware may also include an interface 345 which allows for receipt of data from input devices such as a keyboard 350 or other input device 355 such as a remote control, a pointing device, a video input device and/or an audio input device. [0038] The above-disclosed features and functions, as well as alternatives, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements may be made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.

A method for protecting stored account data from unauthorized access includes receiving data elements corresponding to an account of a user, identifying a plurality of signals in the data elements, and determining a signal value for each of the signals. The signals correspond to various characteristics of the account. The method also includes assigning a plurality of weights (according to various criteria) to at least a subset of the signal values to yield a set of weighted signal values, and using the set of weighted signal values to assign an account value to the account. The method further includes using the account value to select a security-related action or a storage-related action that corresponds to the account value, and instructing data storage facilities from which the data elements were received to automatically implement the selected security related action or the selected storage-related action.

BACKGROUND OF THE INVENTION [0001] The present invention relates generally to surgical tools and more particularly for surgical tools used in conjunction with valve repair, including tools for holding prostheses such as annuloplasty rings and bands. [0002] Annuloplasty rings and bands are useful in a variety of surgical procedures, including mitral and tricuspid annular reduction. In these procedures, sutures are first placed around all or portions of the valve annulus at spaced intervals. Sutures passing through the annulus in regions in which reduction of the valve annulus is desired are spaced equidistant from one another, for example, at 4 mm intervals. These sutures are then brought through the annuloplasty ring or band more closely spaced than where they pass through the annulus, for example, 2 mm. The process of passing the sutures through the ring or band occurs while the prosthesis is held above the valve annulus. The ring is then moved down into contact with the valve annulus, causing contraction of the annulus, thus effecting a reduction in valve annulus circumference. This basic procedure is used to correct both mitral and tricuspid annular dilatation. [0003] In order for the sutures to be passed through the annuloplasty ring, it is desirable that the ring be held in a fixture or tool of some fashion. One early tool was manufactured by Pilling Instruments, and took the general form of a cone provided with a circumferential groove near the base. The cone was also provided with longitudinal slits, so that the tool could be contracted to accept the ring around the circumference of the groove. The tool was adapted to be held by means of a threaded handle. [0004] More recent holder designs are disclosed in U.S. Pat. No. 6,283,993, wherein sutures passing through the prosthesis are used to retain it in a circumferential groove on the holder. An alternative design is disclosed in U.S. Pat. No. 5,011,481, which employs radially and downwardly extending fingers in conjunction with sutures passing around the prosthesis to retain it on the holder. Yet another alternative design is disclosed in U.S. Pat. No. 5,522,884, in which an adjustable annuloplasty ring is retained on its holder by tightening the adjusting sutures within the ring to contract it into a circumferential groove on the holder. [0005] Examples of flexible annuloplasty bands and rings are also disclosed in the above cited patents, all of which are incorporated herein by reference in their entireties. SUMMARY OF THE INVENTION [0006] The present invention is directed toward an improved holder for use with annuloplasty prostheses. The holder is specifically configured to assist the surgeon in performing the technique of mitral or tricuspid reduction, and is typically provided in conjunction with the annuloplasty ring or band, ready for use. The holder takes the general form of an oblate ring component having an upper surface, a lower surface, a central opening and an outer circumferential surface corresponding generally to the configuration of a valve annulus. The prosthesis extends around at least a portion of this circumferential surface and is releasably retained alongside this surface during the passing of sutures through the prosthesis. [0007] The present invention provides improvements directed to the mechanism for retaining the prosthesis on the holder during passage of the sutures and releasing the prosthesis after positioning on the valve annulus. Rather than retaining the annuloplasty ring to the holder by means of sutures passing through the annuloplasty ring, the ring is retained by means of downwardly extending penetrating members such as barbs, pins, pegs, or needles, which enter the annuloplasty prosthesis and retain it to the holder during passage of sutures through the prosthesis. These penetrating members may be fabricated of metal or molded plastic and are sufficiently rigid that they are not readily deflected outward to allow outward movement of the annuloplasty prosthesis away from the holder. The penetrating members may have sharpened or relatively blunt tips. [0008] The preferred embodiment is a two-component holder in which the first component includes the circumferential surface around which the prosthesis is mounted and the second component carries the penetrating members. The first component also typically includes radially extending projections that prevent the prosthesis from moving downward off of the penetrating members, until upward movement of the second component. In a preferred embodiment, the first and second holder components are retained to one another, for example by means of a suture or sutures coupling the first and second components together. In this embodiment, the first and second components become movable relative to one another following cutting of the suture or sutures retaining them together. The first and second holder components are preferably molded of generally rigid plastics but might in some cases be fabricated of metal or other materials. [0009] The present invention generally is intended to provide a simplified and more easily employed mechanism for holding the annuloplasty prosthesis during passage of the sutures through the prosthesis and for releasing it from the holder after the ring has been moved downward into its intended location on the valves annulus. [0010] The holder of the present invention is also provided with a mechanism for assisting the surgeon in the surgical repair of broken or elongated chordae tendinae (chords), as is sometimes performed in conjunction with placement of an annuloplasty prosthesis. This is accomplished by means of a suturing guide extending across the central opening through the holder, approximating the line of leaflet coaption. Sutures used to reconnect the inner edges of the valve leaflets to the papillary muscles are knotted around the suturing guide and the leaflet edge, to assure that the length of the suture is appropriate to allow leaflet coaption. [0011] The suture guide may be any elongated structure, such a rod, bar or cord, but in the preferred embodiment of the invention, the suture guide takes the form of a suture or sutures, extending across the opening through the holder. Cutting the suture allows it to be pulled through the knots at the leaflet edge, facilitating removal of the holder. In the disclosed embodiment, the suture or sutures extending across the central opening are extensions of sutures holding the first and second components closely adjacent one another, routed so that cutting the sutures to allow their removal from the knots at the leaflet edge also releases the first and second components so that the second component may move upward relative to the first component, allowing removal of the annuloplasty prosthesis from the holder. [0012] While in the preferred embodiments described below, the suture guide is part of a two-component annuloplasty prosthesis holder, the suturing guide may also be incorporated in a one-piece holder or in a stand-alone tool which does not carry an annuloplasty prosthesis. In such embodiments, the tool could include a single ring-shaped component corresponding generally to the annulus of the valve to be repaired and the suturing guide could extend across the central opening through the ring shaped component in a manner analogous to its location in the disclosed preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS [0013] [0013]FIG. 1 illustrates a prior art annuloplasty prosthesis and holder, after passage of sutures through the annuloplasty prosthesis. [0014] [0014]FIG. 2 illustrates a cross section through a prior art annuloplasty prosthesis holder. [0015] [0015]FIG. 3 is a perspective view of a two-component annuloplasty prosthesis holder according and associated handle according to a preferred embodiment of the present invention. [0016] [0016]FIG. 4 is a perspective view from above of the embodiment of FIG. 3, with the handle removed. [0017] [0017]FIG. 5 is a perspective view from below of the embodiment of FIG. 3. [0018] [0018]FIG. 6 is a perspective view from below of the embodiment of FIG. 3, illustrating the second component moved upwardly from the first component to release the annuloplasty prosthesis. [0019] [0019]FIGS. 7A and 7B are a cross sectional views through portions of the first and second components of the embodiment of FIG. 3, illustrating interconnection of the prosthesis and the holder components. [0020] [0020]FIGS. 8A and 8B are cut-away views illustrating the use of the holder of FIG. 3 in conjunction with a surgical repair procedure. [0021] [0021]FIG. 9 is a perspective view of a second embodiment of two-component annuloplasty prosthesis holder according and associated handle according to a preferred embodiment of the present invention. [0022] [0022]FIG. 10 is a perspective view from below of the embodiment of FIG. 9. [0023] [0023]FIG. 11 is a perspective view from below of the embodiment of FIG. 9, illustrating the second component moved upwardly from the first component to release the annuloplasty prosthesis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0024] [0024]FIG. 1 is a perspective view of a two-piece annuloplasty holder according to the prior art. In particular, the holder system as illustrated is described in the brochure “Medtronic Duran Flexible Annuloplasty Systems In Service Guide”, published by Medtronic, Inc. in 2000, Publication No. UC200004685 EN, incorporated herein by reference in its entirety. The holder system includes a handle 16 which may be made of metal or plastic, and which may, in some embodiments, include a malleable shaft allowing for manual reconfiguration of the shaft. The shaft is snapped into the holder itself, which includes two components 10 and 12 that are molded of rigid plastic. The upper component 10 of the holder is transparent and serves as a template, including markings illustrating the locations of the valve trigones and regularly spaced markings assisting in placement of sutures around the annuloplasty prosthesis 13 . As illustrated, the first component 12 of the prosthesis releasably secured to the second component 10 of the prosthesis and the annuloplasty prosthesis 13 is mounted around a circumferential surface of the first holder component 12 . [0025] As illustrated, sutures 14 have been passed through the valve annulus 18 and upwardly and outwardly through the prosthesis 13 itself, according to conventional practice for implantation of annuloplasty prostheses. The holder system is then used to move the prosthesis 13 downwardly along the sutures so that it is seated adjacent to the upper surface of the annulus 18 . The second component 10 of the holder may be removed from the first component 12 by cutting the sutures holding them together, leaving the ring mounted around the first holder component 12 , seated adjacent the valve annulus. Although not visible in this view, the first component 12 of the holder includes a large central orifice, so that testing to assure that leaflets of the heart valve co-apt can be accomplished while the prosthesis 13 remains on the first component 12 of the holder. In the particular product marketed by Medtronic, Inc., removable of the prosthesis 13 from the first holder component 12 was accomplished by cutting sutures that held the prosthesis on the holder. [0026] [0026]FIG. 2 is a cross section through the first and second components of the holder illustrated in FIG. 1, in conjunction with attached annuloplasty prosthesis 13 . In this view it can be seen that the second component 10 of the holder is provided with a formed recess 15 configured to releasably engage a handle 16 (FIG. 1). In this view also it can be seen that the first holder component 12 defines a large central aperture illustrated generally at 17 , through which operation of the associated heart valve can be observed after removal of the second holder component 10 . As noted above, component 10 is held to component 12 by means of cuttable sutures, and prosthesis 13 is likewise maintained mounted to component 12 by means of cuttable sutures. Mounting of the prosthesis 12 to the first component 12 of the holder by means of these sutures requires handwork, increasing the expense and complexity of production of the system comprising the holder and the prosthesis. In addition, release of the prosthesis 13 from the first holder 12 requires multiple cuts of the sutures holding the prosthesis to the first holder component 12 , complicating the procedure for releasing the prosthesis from the holder. [0027] [0027]FIG. 3 is a perspective view of a second embodiment of a two-piece holder according to the present invention, with handle 209 attached. In this embodiment, annuloplasty prosthesis 204 is mounted against an outer circumferential surface of first holder component 202 , which is in turn retained against second holder component 200 . The second holder component 20 is provided with a snap fitting 210 , engaging a pin on the end of the handle 209 . The snap fitting may be replaced by a threaded recess or other mechanical mechanism for connecting to the handle 209 . Snap fitting 210 is mounted to a removable base 211 , which is retained to cross bar 208 of component 200 by means of suture 213 , which is captured to base 211 . Handle 209 and base 211 are removed together after cutting suture 213 at slot 215 . Sutures 206 retain component 200 adjacent component 202 . Sutures 206 are tied to component 200 in the vicinity of grooves 207 and 205 . When cut at grooves 207 , component 200 is released to move upward relative to component 202 , in turn releasing the annuloplasty prosthesis 204 , as described in more detail below. [0028] In this view it can seen that substantial apertures are defined through the assembly comprising components 200 and 202 , allowing for testing of the coaption of valve leaflets. The portions of sutures 206 extending across the apertures, between the edges of component 200 and cross bar 208 serve as a suturing guide to assist the physician in repair of leaflets with damaged chordae tendinae, as discussed in more detail in conjunction with FIGS. 8A and 8B. [0029] [0029]FIG. 4 is a perspective view from above of holder components 202 and 200 and prosthesis 204 as illustrated in FIG. 3 showing removal of the handle 209 and base 211 after cutting of suture 213 . While the preferred embodiment as illustrated employs a relatively small base 211 to which the handle is mounted, in alternative embodiments a template as discussed in conjunction with FIGS. 1 and 2, held to component 200 by cuttable sutures, might be substituted for base 211 . Alternatively, base 211 might be omitted and snap fitting 210 might instead be formed as part of the crossbar 208 . In yet other alternative embodiments some or all of crossbar 208 might be replaced with an additional suturing guide. In some such embodiments, the snap fitting 210 might be mounted adjacent to the inner periphery of component 200 . [0030] [0030]FIG. 5 is a view from below of the first and second holder components 202 and 200 in conjunction with the annuloplasty prosthesis 204 . Numbered elements correspond to those in FIG. 3. In this view, the routing of the sutures 206 to retain first and second holder components 202 , 200 closely adjacent to one another is further illustrated. Sutures 206 are tied to component 202 adjacent its outer periphery by knots 201 , of which only one is visible. Free ends of sutures 206 then extend upward through component 200 , across slots 207 (FIG. 3), back downward through component 200 , along L-shaped slots 221 and across the apertures through component 202 to slot 229 in crossbar 208 . Sutures 206 then pass upward through crossbar 208 , along slot 205 (FIG. 7) back downward through crossbar 208 and are tied at knots 203 to retain them to the crossbar. [0031] In operation, the first and second components of the holder work as follows. When first and second holder components 202 , 200 are located closely adjacent to one another as illustrated, pins 214 (not visible in this view) extending downward from component 200 extend through prosthesis 204 . Projections 220 extend radially outward from the first holder component 202 adjacent the lower surface of prosthesis 204 preventing downward movement of the prosthesis off of pins 214 . This mechanical interrelation is illustrated in more detail in FIGS. 10 and 11A, discussed below. When released, component 200 can move upwardly enough to withdraw the pins 214 from prosthesis 204 . Projections 220 are configured to allow them to bend inwardly after upward movement of component 200 , facilitating removal of the prosthesis 204 . This mechanism is also discussed in more detail in conjunction with FIGS. 6 and 7A. Holder components 200 and 202 are mechanically captured to one another by means of interacting tabs and grooves in regions 224 of the holder, described in more detail in conjunction with FIG. 7B. [0032] [0032]FIG. 6 is a view from below of the first and second holder components 202 and 200 in conjunction with the annuloplasty prosthesis 204 . Numbered elements correspond to those in FIGS. 3 - 5 . In this view, sutures 206 have been cut at slots 207 , allowing for holder component 200 to be moved slightly upwardly from holder component 202 . Holder component 200 has moved upwardly enough to withdraw pins 214 from prosthesis 204 . The prosthesis 204 is removed over projections 220 , leaving it positioned adjacent to valve annulus. In this view, it can be seen that pins 214 extend through openings or interruptions 223 in the circumferential flange 226 located adjacent the upper edge of component 202 . As illustrated in more detail in FIG. 7A, projections 220 can pivot inwardly, facilitating removal of the prosthesis 204 from the holder after circumferential wall 228 of component 200 has moved upward of the projections 220 and no longer prevents their inward motion. [0033] In the specific embodiment illustrated, pins 214 extend all the way through the prosthesis 204 and into corresponding holes 221 in the lower, radially extending projections 220 . In other embodiments, pins 214 may be shortened and need not extend all the way to or into the lower radially extending projections 220 . As discussed above, extension of the pins 214 to or preferably into the projections 120 may be especially desirable if the annuloplasty prosthesis 204 is very flexible and or extensible and may be less beneficial if the annuloplasty prosthesis 204 is a generally rigid or inextensible prosthesis. While the prosthesis 204 as illustrated takes the form of an annuloplasty ring, the holder may also be used with a band. In such case, the pins 214 are preferably located so that they will pass through the band adjacent its ends. [0034] [0034]FIG. 7A illustrates a cross-sectional view through a portion of the combination of first holder component 200 , second holder component 202 and the prosthesis 204 . In this view, illustrating the situation prior to upward movement of the second holder component. Pin 214 passes through the aperture 223 in the outwardly extending flange 226 (FIG. 6) of upper component 220 , extends through prosthesis 204 and terminates in hole 221 in projection 220 . Outwardly extending projection 220 prevents downward movement of the prosthesis 204 off of pin 214 . Preferably, the thickness of first component 200 is reduced at 219 to define a hinge point, allowing projection 220 to pivot inward after upward movement of circumferential wall 228 has occurred. [0035] [0035]FIG. 7B illustrates a cross-sectional view of a portion of the assembly comprising first and second holder components 202 , 200 and prosthesis 204 . This cross-section is taken through one of the regions 224 illustrated in FIGS. 5 and 6. Holder components 200 and 202 are retained to one another by projections or tabs 213 located slidably within grooves 215 , allowing upward movement of second component 200 until the lower end of 217 of groove 215 contacts the projection 213 . This mechanism limits upward movement of the second holder component 200 and retains first and second holder components 200 , 202 together, as illustrated in FIG. 6. [0036] [0036]FIGS. 8A and 8B are cut-away views illustrating the utility of sutures 206 in conjunction with surgical repair of broken or elongated chordae tendinae (chords), as is sometimes performed in conjunction with placement of an annuloplasty prosthesis. The basic procedure involved is described in the article “Surgical Techniques For The Repair Of Anterior-Mitral Leaflet Prolapse” by Duran, published in the Journal Of Cardiovascular Surgery, 1999; 14:471-481, incorporated herein by reference in its entirety. As illustrated in FIG. 8A, a double-armed suture 252 is first attached to the papillary muscle 256 by means of a pledget 258 . Alternatively, as described in the Duran article, if multiple chords are to be replaced, a loop of suture may be attached to the papillary muscle and multiple double-armed sutures passed through the loop for attachment to the valve leaflet or leaflets. Suture 252 is intended to replace the broken chord 255 . The free ends of the suture 252 are passed upward and sutured to the edge of valve leaflet 250 , previously attached to the papillary muscle 256 by means of the broken chord. [0037] In the procedure as described in the above cited Duran article, adjustment of the height of the leaflet 250 to determine proper placement of knots 254 , coupling the sutures 252 to the leaflet 250 was accomplished by means of an additional suture passed through the leaflet, held upward by means of forceps to adjust the appropriate leaflet height. In conjunction with the present invention, after the annuloplasty prosthesis 204 has been moved downward and sutured to the valve annulus, suture 206 is used as a suturing guide for determining the proper point at which knots 254 are tied, to assure that the leaflet 250 will coapt properly with the adjacent leaflet 251 . Knots 254 comprise a series of knots, the first of which is tied around suture 206 . The remaining knots are tied thereafter. One or more repairs of this type may be made along the portions of suture 206 extending across the apertures through the annuloplasty prosthesis holder, depending upon the number of chords that are broken. In the embodiment as illustrated in FIGS. 3 - 5 above, the path of the sutures 206 as they cross the apertures through the annuloplasty holder is intended to generally approximate the line of coaption of the leaflets of a mitral valve, facilitating their use in this particular surgery. Other possible routings for the sutures 206 might be substituted in conjunction with other possible valve repair surgeries. [0038] [0038]FIG. 8B illustrates the production of knots 254 to anchor sutures 252 to the valve leaflet 250 in more detail. In this view it can be seen that one of the free ends of the suture 252 is passed upward through the valve leaflet, around the edge of the valve leaflet and through the leaflet again, while the other free end is simply passed up through the valve leaflet. The free ends are knotted together around suture 206 and the series of knots is continued until an adequate number of knots are provided to safely anchor the suture 252 to the valve leaflet 250 . [0039] After the leaflet repair is complete, sutures 206 are cut at slots 207 (FIG. 3) as discussed above to allow annuloplasty holder component 200 to move upward relative to component 202 (FIG. 6) to release the prosthesis 204 . This also allows the cut ends of the sutures 206 to be pulled through the knot or knots 254 , as the holder assembly is moved upward away from the valve annulus. While sutures 206 , provide a preferred mechanism for facilitating the repair procedure discussed above, it is possible that other structures could be substituted for them, including other types of tensile members or more rigid members such as rods or bars, provided that provision is made for removal of the structures from the knots 254 , after the surgical repair is complete. [0040] [0040]FIG. 9 is a perspective view of an alternative embodiment of the present invention which operates in the same general manner as the embodiment illustrated in FIGS. 3 - 8 B, described above. The embodiment of FIG. 9 does include some differences in structure and function, which are discussed in more detail below. [0041] The handle 209 A is somewhat modified from the handle illustrated in FIG. 3, in that the lower end of the handle is provided with two inwardly deflectable arms 209 B, each carrying an outwardly extending projection at their lower end, engaging in corresponding apertures 210 B in snap fitting 210 A. Base member 211 A otherwise corresponds generally to base member 211 discussed above, and is secured to holder component 200 A by means of suture 215 A in the same fashion as described in conjunction with base member 211 described above. [0042] The suturing guide 206 A takes the form of a cuttable suture, routed in a manner analogous to that of the above-described embodiment. However, cutting guides 207 A are formed as grooves in the upper surface of component 200 A rather than penetrating through the component. Further, two additional retention sutures 206 B are provided, which operate to retain component 200 A to component 202 A, in addition to the retention function performed by the sutures 206 A. Sutures 206 B are also associated with cutting guides 207 A, which take the form of slots formed in the upper surface of component 200 A. Cutting of the sutures 206 A and 206 B at all four of the cutting guides 207 A is required in order for component 202 A to be moved downward relative to component 200 A to release the prosthesis 204 A, in a manner analogous to that described in conjunction with the embodiment discussed above. [0043] [0043]FIG. 10 is a perspective view from the lower surface of the embodiment of FIG. 9. All numbered components correspond to identically numbered components illustrated in FIG. 9, discussed above. [0044] [0044]FIG. 11 is a perspective view from below the embodiment of FIG. 9 with component 202 A moved downward relative to component 200 to release prosthesis 204 B. In order for component 200 A to move downward relative to component 200 A, all of the sutures 206 A and 206 B must be cut at cutting guides 207 A (FIG. 9). [0045] In this view, the routing of sutures 206 A and 206 B is more clearly illustrated. Sutures 206 A are anchored to component 202 A by passing them through two adjacent holes in component 202 A and knotting the sutures at 201 A to retain them to component 202 A. One end of each suture 206 A is then passed upward through adjacent holes the components 202 A and 200 A, extended across a cutting guide 207 A (FIG. 9), passed downward through adjacent holes in components 200 A and 202 A on the other side of cutting guide 207 A and passed through slot 221 A. The sutures 206 A are then extended across the aperture through component 202 A, where they are anchored to crossbar 208 A by means of knot 203 A in a manner identical to that described in conjunction with the embodiment of FIGS. 3 - 8 B. Sutures 206 B are first anchored to component 202 A by being looped through adjacent holes through component 202 A and knotted at 201 B. One free end of each suture 206 B is then passed upward through adjacent holes in components 202 A and 200 A, extended across a cutting guide 207 A (FIG. 9), passed downward through adjacent holes in components 200 A and 202 A on the other side of cutting guide 207 A and knotted at 201 C to retain components 200 A and 202 A adjacent to one another. As illustrated, the free ends of the suture 206 B are shown after cutting to allow downward movement of component 202 A relative to component 200 A. [0046] In this view it can also be seen that the needles 214 A, rather than being provided with sharp tips as in the embodiment of FIGS. 3 - 8 described above, are provided with rounded or ball-tip ends. The needles 214 A pass through prosthesis 204 A and operate to retain the prosthesis to the holder in the same manner as described above in conjunction with the embodiment of FIGS. 3 - 8 B.

A valve repair system, preferably including an annuloplasty prosthesis and a holder for the prosthesis. The holder includes a first component having a central opening, a circumferential surface and an outwardly extending member. The annuloplasty prosthesis is located adjacent to the circumferential surface, above the outwardly extending member. The holder further includes a second component movable upwardly relative to the first holder component and includes a rigid penetrating member extending downward from the second component into the prosthesis, holding it adjacent the circumferential surface. The holder also includes a suturing guide for assisting a physician in valve repair surgery, which may be a cuttable suture extending across the central opening along a path approximating a desired line of leaflet coaption. The cuttable suture may additionally secure the first and second components to one another. The suturing guide may also be incorporated into one-piece annuloplasty prosthesis holders or into stand-alone tools that do not carry annuloplasty prostheses.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to production of items with graphical images thereon. [0003] 2. Background Information [0004] Pull-down window shades have existed for near countless years, yet they have changed little since their inception. A window shade is, and always has been, a (usually) rectangular piece of fabric or plastic sheeting, wound about a spring loaded roller, often with a pull ring affixed to the lower, distal edge. [0005] Rendering a window shade decorative has, to date, been a matter, principally, of choosing an attractive fabric (substrate) from which the shade is to be produced and/or treating the lower, distal edge with features such as scalloping or fringe. If one were to desire an image (artwork, for example) to appear on a window shade, one would be required to choose, as the substrate, a pre-printed fabric with a pattern or graphic already applied thereto. The only other option is to individually paint or draw the desired image onto window shade substrate on an individual basis. [0006] Clearly, the latter option is not cost-effective and would eliminate all but hobby type involvement for producing custom-decorated window shades. The price point of a custom-painted window shade would be prohibitive in almost all contexts. [0007] As to the first stated option, any single desired alternative to a conventional, solid color (usually white or off-white) window shade designs, involving graphics, for example, is likely to be of very limited appeal, such that sales could not support reasonable production runs of specially decorated window shades, using present methods. [0008] Thus, window shades having artistic reproductions, graphical designs, and even school or corporate logos are simply not feasible under all but the rarest of current conditions. Clearly, single run, or very limited run production of decorative window shades is almost always cost-prohibitive. [0009] The present impediments to producing graphically decorated window shades as just described conflicts with the desirability of having graphically decorated window shades. [0010] For lack of a better description: window shades at present are boring. Certainly, there are alternatives to window shades, including blinds and curtains. However, window shades are almost universally less expensive than blinds and drapery. Are those who can only afford window shades to shade their windows to have no decorative options beyond the plain white or off-white window shade? The answer, made possible by the present invention, and consistent with the following objects, is no. SUMMARY OF THE INVENTION [0011] It is an object of the present invention to provide an improved, aesthetically pleasing window shade produced through a novel process for producing window shades. [0012] It is another object of the present invention to provide an improved, aesthetically pleasing window shade produced through a novel process for producing window shades which involves the computer-controlled printer application of large graphical images onto such window shades. [0013] It is another object of the present invention to provide a process by which custom or short-run window shade designs, not possible through existing window shade manufacturing processes, and involving graphical images appearing thereon, may be cost-effectively produced. [0014] In satisfaction of these and related objects, the present invention includes a process for producing a window shade with a graphic image imprinted thereon, and a window shade produced through such process. No window shade with a printed graphical image, nor process for creating such a window shade is known to exist. [0015] The present process and product by process revolves around the initial generation of a digital image file which can ultimately be processed by a large format color printer to reproduce a selected graphic image (much enlarged) onto window shade substrate. [0016] Because the present process, for the first time, allows window shade substrate to be quickly, individually, and inexpensively produced using any graphical image that can be digitally scanned, even single item production of custom window shades with a single, unique graphic is not cost-prohibitive. Images for application to window shade substrate are near infinite in character—artwork, individual photographs, college logos, and business logos are among the choices. An even more creative option for graphic selection may involve printing a reproductions of to-be-adjacent wall paper or wall treatment designs onto shades, in order to coordinate the shade with existing room decorations. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0017] It is clear that certain variations and substitutions of equipment and software will fall within the scope of the present invention. Nevertheless, the presently preferred embodiment and best mode for practicing the present method and producing the product-by-process described previously is exemplified as follows: [0018] 1. Unless already available in digital file format (such as is often the case with corporate or school logos, and the like, scan original art, graphic, or photo using a flatbed scanner, setting the controlling software at the maximum scanner enlargement setting, and in RGB color mode at 300 dpi resolution. Save scanned file in Tag Image File (“TIF”) format. [0019] 2. Open TIF file with a digital photo software package, such as ADOBE PHOTOSHOP or MICROSOFT PICTURE-IT. [0020] 3. Using free hand painting, or clone painting tools (such as is available in both of the stated example software packages, touch up any imperfections, dust particles, scratches, etc. The touch up is an important step in order to ensure the quality of the final print, because imperfections of the original scan will be greatly magnified in the final shade substrate printing. [0021] 4. Enlarge image sufficiently to achieve a suitably large shade size image. [0022] 5. If detail is lost in the enlargement, application of the software's image sharpening filter will often remedy the problem. [0023] 6. Convert RGB color mode to CMYK color mode in order to adjust color using color specific image masking techniques which, in turn, helps achieve color accuracy and vibrancy. [0024] 7. Save file in EPS format with JPEG preview. [0025] 8. Open QUARK XPRESS software program and make new file proportional to desired final size and within the programs 48 maximum page size. [0026] 9. Import binary EPS file into QUARK XPRESS file. [0027] 10. Set large format color printer as output destination in QUARK XPRESS. [0028] 11. Configure large format color printer with suitable ink(s) for the desired substrate (dye-based inks, UV inks, oil-based inks, and solvent based inks). [0029] 12. Load shade media roll into printer. Examples of suitable shade media include (but are not limited to): [0030] A. Scrim Vinyl Banner (ROLAND or MAGIC brands) [0031] B. Poly Silk Soft cloth (ROLAND brand) [0032] C. Artist Canvas (MAGIC brand) [0033] D. Banner cloth (ROLAND brand) [0034] E. Premium matte vinyl (ROLAND brand) [0035] F. Tyvek Banner (ROLAND brand) [0036] G. Heavy duty Banner (ROLAND brand) [0037] H. Banner Polyethylene (MAGIC brand) [0038] I. Banner Poly propylene ( MAGIC brand) [0039] J. Banner I BOP ( MAGIC brand) [0040] 13. Determine enlargement percentage for desired size and send to printer. [0041] 14. Set desired raster settings on printer and rasterize file. [0042] 15. Release rastered file to print. [0043] 16. Once printing is complete the media is cut loose from the printer. [0044] 17. Trim excess material with EXACTO knife and safety trim cutting ruler (or other suitable cutting method). Note: Four to five inches of material (outside of the printed image) is left at top and bottom. Top end of material, outside of the image area is adhered to a window shade roller. [0045] 18. A loop called a pocket pole is made on the bottom end which will hold a wooden or plastic slat. [0046] Depending on the quantity of orders, the pocket pole can be made using a permanent adhesive, or heat sealer, or sewing machine. [0047] 19. Material is attached to roller using a permanent adhesive. [0048] A non-exclusive list of examples of large format printers which may be used in the present process include the GRAND SHERPA model wide format printer from the Agfa Company, the STYLUS PRO 10000 from the Epson company, the DISPLAYMAKER XII by the ColorSpan company, and the HP 5000 wide format printer from Hewlett Packard. Discussions of the strengths, weaknesses, and capabilities of these printers, as well as operating procedures, suitable (or included) driver software and compatible graphics software, acceptable printing media, and so forth, may be found at or through contacts provided at www.wide-format-printers.org. If such site become unavailable, a web browser search including “large format printers” will readily yield such information. [0049] Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.

A process and product by process involving the production of window shades with graphics printed thereon using computer-controlled, large format printers.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of the filing date under 35 USC 119(e) of the filing date of U.S. Provisional Application Ser. No. 60/674,785, filed Apr. 26, 2005. BACKGROUND [0002] This application relates generally to driving tools such as screwdrivers, nut drivers, bolt drivers, wrenches and the like wherein the amount of torque that the tool can apply to a given fastener is limited to a settable value. More specifically, this application relates to a torque locking mechanism usable in said tools that allows a fine range of torques for a given tool and prevents the inadvertent change of the torque setting once set. [0003] Torque settable drivers as described above are well known in the art. This application relates to drivers that are designed for specific uses and thus a lockable torque value is desirable. The need for a lockable torque-limiting driver that can drive a given fastener at a desired torque value is useful in a variety of fields including sporting goods, electronics and computer assembly, and any other use wherein specific tolerances are required. However, it would be desirable if there was a tool that would allow for a fine range of torque setting such that a given tool could be effectively locked into a variety of specific torque settings. It would also be desirable for such a tool to be low-cost and suitable for mass production without sacrificing precision. SUMMARY [0004] This application discloses a settable torque-limiting driver that is economical to produce, of simple construction and capable of mass production, but also capable of being locked in a variety of precise torque settings. [0005] In particular, this application discloses a lockable torque-limiting driver that includes gripping means, a body, a sleeve, a shaft carried by the body for rotation relative thereto and having a fastener-engaging tip at one end that projects from the body, torque-limiting means coupled to said shaft and housed within said body, torque-adjusting means within said body and coupled to said torque-limiting means for adjusting the torque-limiting means to a desired torque value, torque-locking means operably coupled with said torque-adjusting means and said body for preventing movement of said torque-determining means and locking the settable torque-limiting driver at the desired torque value. [0006] In another embodiment, this application discloses a lockable torque-limiting driver that includes gripping means, a body, a sleeve, a shaft carried by the body for rotation relative thereto and having a fastener-engaging tip at one end that projects from the body, torque-limiting means coupled to said shaft and housed within said body, torque-adjusting means within said body and coupled to said torque-limiting means for adjusting the torque-limiting means to a desired torque value, torque-locking means operably coupled with said torque-adjusting means and said sleeve for preventing movement of said torque-determining means and locking the settable torque-limiting driver at the desired torque value. [0007] In a further embodiment, this application discloses a method for locking a settable torque-limiting driver at a desired torque value by providing a torque-limiting mechanism coupled to a shaft and housed within a body, setting a torque-adjusting mechanism coupled to said torque-limiting mechanism, and engaging the torque-adjusting mechanism with a torque-locking mechanism. [0008] In yet a further embodiment, this application discloses a golf club weight attachment system comprising: a golf club capable of being adjusted by securing screwably attachable weights in defined positions at a desired torque setting on said club; and, a lockable torque-limiting driver for securing said weights to said golf club at a defined torque setting wherein the driver comprises a body; a sleeve carried by said body; a shaft carried by said body for rotation relative thereto and having a weight-engaging tip at one end that projects from the body for screwably attaching said weights; torque-limiting means coupled to said shaft and housed within said body; torque-adjusting means within said body and coupled to said torque-limiting means for adjusting the torque-limiting means to the desired torque value; and, torque-locking means operably coupled with said torque-adjusting means and said body or said sleeve for preventing movement of said torque-determining means and locking the settable torque-limiting driver at the desired torque value such that the weights are attached to the golf club at the desired torque value. BRIEF DESCRIPTION OF THE DRAWINGS [0009] The drawings, when considered in connection with the following description, are presented for the purpose of facilitating an understanding of the subject matter sought to be protected. [0010] FIG. 1A is a front elevational view of a lockable torque-limiting driver; [0011] FIG. 1B is a sectional view of the driver taken generally along the line 1 B- 1 B in FIG. 1A showing a first embodiment of the locking mechanism; [0012] FIG. 1C is an exploded view of the driver of FIG. 1A ; [0013] FIG. 2A is a front elevational view of a lockable torque-limiting driver; [0014] FIG. 2B is a sectional view of the driver taken generally along the line 2 B- 2 B in FIG. 2A showing a second embodiment of the locking mechanism; [0015] FIG. 2C is an exploded view of the driver of FIG. 2A ; [0016] FIG. 3A is a front elevational view of a lockable torque-limiting driver; [0017] FIG. 3B is a sectional view of the driver taken generally along the line 3 B- 3 B in FIG. 3A showing a third embodiment of the locking mechanism; [0018] FIG. 3C is an exploded view of the driver of FIG. 3A ; [0019] FIG. 4 is a 90° side elevational view of the driver of FIG. 1A ; [0020] FIG. 5 is a sectional view of the driver showing the first embodiment of the locking mechanism of FIG. 1B taken generally along the line 5 - 5 in FIG. 4 ; [0021] FIG. 6 is a perspective view of the rotational cam of FIGS. 1C, 2C , and 3 C; [0022] FIG. 7 is a perspective view of the non-rotational cam of FIGS. 1C, 2C , and 3 C; [0023] FIG. 8 is perspective view of the sleeve of FIGS. 1C and 2C ; [0024] FIG. 9A is a top plan view of the sleeve in FIG. 8 ; [0025] FIG. 9B is a side elevational view of the sleeve in FIG. 8 ; [0026] FIG. 9C is a 90° side elevational view of the sleeve in FIG. 9B ; [0027] FIG. 9D is a sectional view of the sleeve taken generally along the line 9 D- 9 D in FIG. 9C ; [0028] FIG. 10 is perspective view of the sleeve of FIG. 3C ; [0029] FIG. 11A is a top plan view of the sleeve in FIG. 10 ; [0030] FIG. 11B is a side elevational view of the sleeve in FIG. 10 ; [0031] FIG. 11C is a 90° side elevational view of the sleeve in FIG. 11B ; [0032] FIG. 11D is a sectional view of the sleeve taken generally along the line 11 D- 11 D in FIG. 11C ; [0033] FIG. 12 is a top plan view of the generally circular member of the body of the driver of FIGS. 1C and 2C , isolated to show its details; [0034] FIG. 13 is a perspective view of the adjustment plug of FIG. 1C ; [0035] FIG. 13A is an additional perspective view of the adjustment plug of FIG. 1C ; [0036] FIG. 13B is a top plan view of the adjustment plug of FIG. 1C ; [0037] FIG. 13C is a side elevational view of the adjustment plug of FIG. 1C ; [0038] FIG. 13D is a 90° side elevational view of the adjustment plug of FIG. 13C ; [0039] FIG. 14 is a perspective view of the locking plate of FIG. 1C ; [0040] FIG. 14A is an additional perspective view of the locking plate of FIG. 1C ; [0041] FIG. 14B is a top plan view of the locking plate of FIG. 1C ; [0042] FIG. 14C is a side elevational view of the locking plate of FIG. 1C ; [0043] FIG. 14D is a 90° side elevational view of the locking plate of FIG. 14C ; [0044] FIG. 15 is a perspective view showing the coupling of the adjustment plug and locking plate of the driver of FIG. 1B ; [0045] FIG. 16 is a perspective view of the locking mechanism of the driver of FIG. 1B ; [0046] FIG. 17 is a fragmentary sectional view along the line similar to the view in FIG. 5 showing the second embodiment of the locking mechanism of the driver of 2 B; [0047] FIG. 18 is a perspective view showing the adjustment plug of the driver of FIGS. 3B and 3C ; [0048] FIG. 18A is an additional perspective view of the adjustment plug of FIGS. 2C and 3C ; [0049] FIG. 18B is a top plan view of the adjustment plug of FIGS. 2C and 3C ; [0050] FIG. 18C is a side elevational view of the adjustment plug of FIGS. 2C and 3C ; [0051] FIG. 18D is a 90° side elevational view of the adjustment plug of FIG. 18C ; [0052] FIG. 19 is a perspective view showing the locking plate of the driver of FIG. 2C ; [0053] FIG. 19A is an additional perspective view of the locking plate of FIG. 2C ; [0054] FIG. 19B is a top plan view of the locking plate of FIG. 2C ; [0055] FIG. 19C is a side elevational view of the locking plate of FIG. 2C ; [0056] FIG. 19D is a 90° side elevational view of the locking plate of FIG. 19C ; [0057] FIG. 19E is a bottom plan view of the locking plate of FIG. 2C ; [0058] FIG. 20 is a perspective view showing the coupling of the adjustment plug and locking plate of the driver of FIG. 2B ; [0059] FIG. 21 is a perspective view showing the locking mechanism of the driver of FIG. 2B ; [0060] FIG. 22 is a fragmentary sectional view along the line similar to the view in FIG. 5 showing the third embodiment of the locking mechanism of the driver of 3 B; [0061] FIG. 23A is an perspective view of the locking plate of FIG. 3C ; [0062] FIG. 23B is a top plan view of the locking plate of FIG. 3C ; [0063] FIG. 23C is a side elevational view of the locking plate of FIG. 3C ; [0064] FIG. 23D is a 90° side elevational view of the locking plate of FIG. 23C ; [0065] FIG. 23E is a bottom plan view of the locking plate of FIG. 3C ; [0066] FIG. 24 is a perspective view showing the locking mechanism of the driver of FIG. 3B ; [0067] FIG. 25 is an additional embodiment of the driver of FIG. 24 showing the locking mechanism of the driver of FIG. 3B used in a T-shaped driver; [0068] FIG. 26 is a sectional view of the driver in FIG. 25 ; and, [0069] FIG. 27 is a perspective view showing a golf club weight attachment system. DETAILED DESCRIPTION [0070] Referring to FIGS. 1A-3C , shown therein and generally designated by the reference character 10 is a lockable toque-limiting driver constructed in accordance with the following description. The driver 10 includes a body 12 having an elongated shaft 14 with a fastener-engaging portion 16 extending from one end thereof. At the other end, the driver 10 is provided with a cap member 18 . [0071] As may be seen more clearly in FIGS. 1B and 5 , the body 12 is comprised of a generally circular upper member 13 and a hollow, generally cylindrical stem portion 15 with a tapered hexagonal shaped in transverse cross section end wall 17 terminating at its end with axial bore 19 formed therethrough. The inner surface of circular member 13 is provided with a plurality of circumferentially spaced channels 20 ( FIG. 12 ). [0072] Referring to FIG. 1B and in particular FIGS. 8-9D , the driver 10 includes a sleeve 21 having an elongated, hollow, generally cylindrical body 22 with circumferentially spaced outwardly projecting flanges 23 positioned to be received in the channels 20 ( FIG. 21 ). Formed along the inner surface of the sleeve 21 , at circumferentially spaced locations, is a plurality of longitudinally extending channels 24 ( FIGS. 9A and 9D ). The cylindrical body 22 has a tapered hexagonal shaped in transverse cross section end wall 25 with an axial bore 26 formed therethrough. The inner surface of sleeve 21 includes threads 27 at its upper and open end ( FIGS. 8 and 9 D). During assembly, sleeve 21 is coaxially received in the stem portion 15 of the driver, with hexagonally shaped sleeve end wall 25 mateably seated in the hexagonally shaped body end wall 17 , ( FIG. 1B ) and flanges 23 mateably received in the channels 20 ( FIGS. 1B and 21 ) thereby preventing rotation of sleeve 21 relative to body 12 . [0073] As shown in FIGS. 2C and 5 , the driver 10 includes an elongated shaft 14 with a fastener-engaging portion 16 at one end. The shaft portion above the engaging portion is hexagonal shaped in transverse cross section. Intermediate to its ends, shaft 14 includes a circumferential groove 30 , operably configured to receive a retaining ring 31 ( FIGS. 2C and 5 ). At the end opposite of the fastener-engaging portion 16 , the shaft 14 includes a bearing end face 32 configured for engagement with a ball bearing 33 . During assembly, the shaft 14 is passed through aligned bores 19 and 26 in the driver stem 15 and sleeve 21 respectively, with the retaining ring 31 seated on the inner surface of sleeve end wall 25 ( FIG. 5 ). [0074] Referring to FIGS. 5-7 , the driver 10 includes torque-limiting means, which may comprise an upper non-rotational cam 40 , a lower rotational cam 41 , and a compression spring 42 . More particularly, upper cam 40 includes an annular body 43 and a cylindrical bore 44 formed axially therethrough. On the outer surface of annular body 43 are circumferentially spaced outwardly projecting splines 45 . The upper cam 40 has an upper face 48 and a lower face comprised of circumferentially spaced teeth 45 , each having a sloping face 46 and an axial face 47 . The lower cam 41 includes an elongated cylindrical portion 49 at one end and an elongated location boss portion 50 at the other. Intermediate and integral with the two portions 49 and 50 is a radially extending annular body 51 that includes a lower face 52 and an upper face comprised of circumferentially spaced teeth 53 , each having a sloping face 54 and an axial face 55 . A hexagonal bore 56 dimensioned to mateably receive shaft 14 is formed through the lower cam 41 . [0075] Referring to FIGS. 2B, 2C and 5 , during assembly, the lower cam 41 is fitted over the shaft 14 within the sleeve 21 with the lower face 52 seated on a thrust washer 57 , which is seated on the sleeve wall 28 . When assembled, the hexagonal bore 56 acts in concert with the hexagonal shaft 14 to prevent rotation of the shaft 14 relative to lower cam 41 . The upper cam 40 is then fitted down coaxially over the upper end of shaft 14 and within sleeve 21 such that the outwardly projecting splines 45 are mateably received by the longitudinal channels 24 on the inner surface of the sleeve ( FIGS. 8A and 9D ) and the teeth 45 of the upper cam are mateably engaged with the teeth 53 of the lower cam 41 . In such an orientation, the upper cam 40 is prevented from rotation relative to the sleeve 21 . And the relative rotation of the upper and lower cams 40 and 41 is prevented in one direction due to the engagement of the axial faces 47 of the teeth 45 with the axial faces 55 of the teeth 53 of the of the upper and lower cams respectively. However, relative rotation of the upper and lower cams 40 and 41 is provided in the opposite direction due to the engagement of the sloping faces 46 of the teeth 45 with the sloping faces 54 of the teeth 53 of the upper and lower cams respectively. Lastly, the torque-limiting means is completed by coaxially fitting the compression spring 42 over the upper end of the shaft 14 , within the sleeve 21 , and seated on the upper face 48 of the upper cam 40 . [0076] The driver 10 includes a torque-adjustment means, which comprises an annular adjustment plug. Two embodiments are described. The first embodiment is shown in FIGS. 1B and 1C , and in particular FIGS. 13-13D . Here the adjustment plug 60 has an annular body 61 with an externally threaded surface 62 , a lower end face 63 , an upper end face 64 and a cylindrical axial bore 65 therethrough. The upper end face 64 is further characterized by an elongated key structure 66 , in this embodiment, a twelve point star formation. The second embodiment of the adjustment plug is shown in FIGS. 2B, 17 and in particular FIGS. 18-18D . Here the adjustment plug 67 has an annular body 68 with an externally threaded surface 69 , a lower end face 70 , an upper end face 71 , and a keyway structure 72 therethrough, in this embodiment, an octagonal bore. During assembly, the adjustment plug 60 or 67 is fitted coaxially over the upper end of the shaft 14 , and threadedly engaged in the upper open end of the sleeve 21 , for bearing against the upper end of the compression spring 42 . The extent to which the adjustment plug 60 or 67 is threaded into the sleeve 21 controls the amount of compression on the spring 42 , which, in turn, controls the force with which the upper cam 40 is driven into engagement with the lower cam 41 . Thus, the limiting torque required to effect the relative rotation of the upper and lower cam can be set to a desired torque value. To effect the threading of the adjustment plug to the desired position, a socket wrench or the like can be used to engage the key or keyway structure, 66 and 72 respectively. [0077] To maintain the desired torque value, the driver 10 includes a torque-locking means, which comprises a locking plate coupled with the adjustment plug and the driver body to prevent the inadvertent movement of the adjustment plug. Again, two embodiments of the locking plate are described to coincide respectively with the two previously described adjustment plug embodiments. The first embodiment is shown in FIGS. 1B, 5 and in particular FIGS. 14-14D . The locking plate 75 has a generally diamond shape and includes an adjustment plug-engaging portion 76 and a body-engaging portion 77 . The plug-engaging portion 76 is characterized by a bored keyway structure 78 , in this embodiment, a twelve point star formation to mateably receive the adjustment plug 60 ( FIGS. 15 and 16 ). The body-engaging portion 77 is characterized by serrations 79 located at opposite ends of the plate 75 , in this embodiment, six serrations per end. The second embodiment of the locking plate is shown in FIGS. 1B, 17 , 21 , and in particular FIGS. 19-19D . Here the locking plate 80 is generally T-shaped and includes an adjustment plug-engaging portion 81 , a body engaging portion 82 , and a cylindrical bore 83 formed axially therethrough. The plug-engaging portion 81 is characterized by an elongated key structure 84 , in this embodiment, a twelve point star formation to mateably receive the adjustment plug 67 ( FIGS. 17 and 20 ). The body-engaging portion 85 is characterized by serrations 86 located at opposite ends of the plate 80 , in this embodiment, six serrations per end. To receive the body-engaging portions of the locking plates 75 and 80 , the body 12 of the driver 10 , and in particular the upper surface of the generally circular upper member 13 , includes locking plate-engagement portions 89 ( FIG. 12 ). In the embodiment shown in FIG. 12 , the locking plate-engagement portions 89 include serrations 87 which are shown integral with the cap location bores 88 to receive the body-engagement portions 77 and 82 respectively ( FIGS. 16 and 21 ). In FIG. 12 , the locking plate-engagement serrations 87 are shown integral with only two of the cap location bores 88 , but it should be appreciated that the engagement serration may be associated with the other cap location bores for even finer adjusting and locking means. [0078] Referring to FIGS. 1B, 1C and 16 , during assembly of the first embodiment of the torque-locking means, locking plate 75 is fitted coaxially over the upper end of shaft 14 , the bored keyway structure 78 of the plug-engagement portion 76 is mateably received by the elongated key structure 66 of the adjustment plug 60 , and the serrations 79 of the body-engaging portion 77 are received by the locking plate-engagement serrations 87 of the upper generally circular member 13 such that the adjustment plug is locked in position. Referring to FIGS. 2B, 2C , 17 and 21 , during assembly of the second embodiment, the locking plate 80 is fitted coaxially over the upper end of the shaft 14 , the elongated key structure 84 of the plug-engagement portion 81 is mateably received by the keyway structure 72 of the adjustment plug 67 , and the serrations 86 of the body-engaging portion 85 are received by the locking plate-engagement serrations 87 of the upper generally circular member 13 such that the adjustment plug is locked in position. [0079] The preferred embodiment of the driver 10 is shown in FIGS. 3A-3C . Referring to FIGS. 3B and 3C , the driver includes a third embodiment of the torque-locking means which comprises a locking plate coupled with the adjustment plug and the sleeve to prevent the inadvertent movement of the adjustment plug. The third embodiment of the locking means utilizes the adjustment plug 67 previously shown in FIGS. 2B, 17 and in particular FIGS. 18-18D . To restate briefly, the adjustment plug 67 has an annular body 68 with an externally threaded surface 69 , a lower end face 70 , an upper end face 71 , and a keyway structure 72 therethrough, in this embodiment, an octagonal bore. Referring to FIGS. 3B and 3C , during assembly, the adjustment plug 67 is fitted coaxially over the upper end of the shaft 14 , and threadedly engaged in the upper open end of the sleeve 29 , for bearing against the upper end of the compression spring 42 . Sleeve 29 is similar to the sleeve 21 previously described, but includes a pair of prongs 29 A located on opposite sides of the upper open end of the sleeve ( FIGS. 10-11D ). The locking plate utilized in the third embodiment of the torque-locking means is shown in FIGS. 3B, 3C , and in particular FIGS. 23A-23E . The locking plate 100 is generally gear shaped and includes an adjustment plug-engaging portion 101 , a sleeve engaging portion 102 , an annular cap-receiving portion 107 , and a cylindrical bore 103 formed axially therethrough. The plug-engaging portion 101 is characterized by an elongated key structure 104 , in this embodiment, an eight point star formation to mateably receive the adjustment plug 67 ( FIGS. 3B and 22 ). The sleeve-engaging portion 102 is characterized by gears 105 about its circumference with undulations 106 to mateably receive the locking plate-engagement portions 29 B, which include prongs 29 A on the upper end of the sleeve 29 ( FIG. 24 ). [0080] Referring to FIGS. 3B, 3C , 22 and 24 , during assembly of the third embodiment, the locking plate 100 is fitted coaxially over the upper end of the shaft 14 , the elongated key structure 104 of the plug-engagement portion 101 is mateably received by the keyway structure 72 of the adjustment plug 67 , and the undulations 106 of the sleeve-engaging portion 102 are received by the locking plate-engagement prongs 29 A on the upper end of the sleeve 29 such that the adjustment plug is locked in position. [0081] To complete the assembly of the driver 10 , a gripping means comprising a cap 18 with a grippable surface 95 and a cushion and/or label 96 ( FIGS. 1A and 1C ) is mounted to the generally circular member 13 . During assembly, a ball bearing 33 is seated in the ball support 91 of the cap 18 ( FIG. 17 ), and the cap is then fitted over the upper generally circular member 13 , to a mounted position shown in FIGS. 5 and 17 . In the mounted position, the ball bearing 33 is held against the bearing end face 32 of the shaft 14 and the location posts 92 ( FIG. 17 ) are mateably received in the cap location bores 88 ( FIGS. 12 and 17 ). The cap may be snap-fitted to the generally circular member 13 , or fixed by sonic welding, solvent welding or the like. When the cap is fixed, the driver is permanently assembled with the torque setting locked in the desired position. [0082] Finally FIG. 27 shows a golf club weight attachment system 100 whereby a lockable torque-limiting driver 10 is locked at a desired torque setting as described above is used with a weight adjustable golf club 101 (as well known in the art) with weights 102 that are screwably attached at locations 104 on the club 101 . The weights 102 are attached to the club 101 by inserting the weight-engaging tip 16 A of the shaft 14 into the weights 102 and then screwably attaching them at locations 104 (at the desired torque setting) so that the desired weight characteristics of the club are realized. See below for a detailed description of the operation of the driver 10 . [0083] Operation of the driver 10 is accomplished by the taking the cap 18 into the user's hand such that the palm rests on the upper surface of the cap and the fingers rest within the grippable surface 95 . In addition to the generally circular driver previously described, the driver 10 may also be substantially T-shaped, and example of which is shown in FIGS. 25 and 26 . For the T-shaped embodiment, it will be appreciated that the inner workings are the same as previously described for the generally circular embodiment and, in operation, the arms 110 of the driver may be rested in the palm of the user's hand, with the fingers wrapped beneath the arms and straddling the stem potion 111 . When the driver in either embodiment is rotated in one direction, the shaft 14 will rotate with the body 12 until the desired torque level is reached, at which point the biasing force exerted by the spring 42 is overcome to allow the sloping faces 46 of the upper cam 40 to slide up the sloping faces 54 of the lower cam 41 for the angular distance of one tooth, at which point the upper cam 40 will snap into engagement behind the next tooth of the lower cam 41 , thereby provide the user a tactile and/or audible indication that the desired torque has been reached. [0084] In the construction of the driver 10 , a majority of the components may be formed of suitable plastics that may be molded, however, components that must withstand load bearing, torsional, and other significant forces such as the retaining ring 31 , spring 42 , shaft 14 and ball bearing 33 may be formed of suitable metals. Based on the forgoing description and accompanying figures, it can be seen that there has been provided an improved lockable torque-limiting driver that allows for a fine range of torque setting such that it can be effectively locked into a variety of specific torque settings. It has also been shown that the driver can be produced at a low-cost and is suitable for mass production without sacrificing precision.

A lockable torque-limiting driver that includes, a body, a sleeve, a shaft carried by the body for rotation relative thereto and having a fastener-engaging tip at one end that projects from the body, a torque-limiting mechanism coupled to the shaft and housed within said body, a torque-adjusting mechanism within the body and coupled to the torque-limiting mechanism for adjusting the torque-limiting mechanism to a desired torque value, a torque-locking mechanism operably coupled with the torque-adjusting mechanism and the body or the sleeve for preventing movement of the torque-determining means and locking the settable torque-limiting driver at the desired torque value.

[0001] This application claims priority from U.S. Provisional Application No. 60/332,409, filed Nov. 16, 2001. FIELD OF THE INVENTION [0002] The present invention relates to the preservation of blood in liquid form. More particularly, the present invention relates to enhancement of the shelf-life of oxygen-depleted refrigerated storage of red blood cells. Still more particularly, compositions and methodology involving nutrient or metabolic supplementation of red blood cells stored in liquid form in oxygen-depleted refrigeration are provided. This invention was made with partial support by the United States Office of Naval Research, Contract No. N00014-98-1-0451. The Government has certain rights in the invention. DESCRIPTION OF THE PRIOR ART [0003] By way of background, currently the supplies of liquid blood are limited by storage. Stored blood expires after about 42 days of refrigerated storage. Red blood cells may, for example, be stored under refrigeration at a temperature above freezing (4° C.) as packed blood cell preparations. Red blood cells may be concentrated from whole blood with separation of the liquid blood component (plasma). Expired blood cannot be used and is discarded. There are periodic shortages of blood that occur due to donation fluctuation, emergencies and other factors. The logistics of blood supply and distribution impact the military, especially during times of combat, and remote hospitals or medical facilities. There is currently a need for the storage of autologous blood to avoid the significant risks of infection associated with non-autologous donor blood. Patients currently cannot collect and store with current technology enough autologous blood for certain pre-planned surgeries, including hip replacement, organ transplantation and the like. [0004] Storage of frozen blood is known in the art but such frozen blood has limitations. For a number of years, frozen blood has been used by blood banks and the military for certain high-demand and rare types of blood. However, frozen blood is difficult to handle. It must be thawed which makes it impractical for emergency situations. Once blood is thawed, it must be used within 24 hours. [0005] U.S. Pat. No. 4,769,318 to Hamasaki et al. is directed to additive solutions for blood preservation and activation. U.S. Pat. No. 5,624,794 to Bitensky et al. and also U.S. Pat. No. 6,162,396 to Bitensky et al. are directed to the storage of red blood cells under oxygen-depleted conditions. U.S. Pat. No. 5,789,151 to Bitensky et al. is directed to blood storage additive solutions. [0006] Additive solutions for blood preservation and activations are known in the art. For example, Rejuvesol (available from enCyte Corp., Braintree, Mass.) is add to blood after cold storage (i.e., 4° C.) just prior to transfusion or prior to freezing (i.e., at −80° C. with glycerol) for extended storage. [0007] In light of current technology, there still remains a long-felt need for the extension of the useful shelf-life of stored liquid blood, especially for extension technology that is relatively inexpensive, easy to handle, and that provides significantly extended long-term storage. [0008] Accordingly, it is an object of the present invention to provide a method for extended storage of red blood cells. [0009] It is another object of the present invention to provide nutrient or metabolic supplements useful with the storage of red blood cells. [0010] Another object of the present invention to provide a method for extending the storage of red blood cells using oxygen-free additive solutions and oxygen removal. [0011] These and other objects and advantages of the present invention and equivalents thereof, are achieved by the methods and compositions of the present invention described herein and manifest in the appended claims. SUMMARY OF THE INVENTION [0012] The present invention provides methods and compositions for extending the useful shelf-life of red blood cells. The method of the invention comprises adding a metabolic supplement to packed red blood cells, adding an additive solution, preferably an oxygen-free additive solution, to said red blood cells, and storing said red blood cells at a temperature above freezing, preferably 4° C., under conditions of oxygen-depletion. Metabolic supplement compositions of the invention comprise pyruvate, inosine, adenine, monobasic and dibasic phosphate salts at a pH from about 5 to about 8. Rejuvesol, or modification thereof, may be used as a metabolic supplement solution. Oxygen depletion may be effected by flushing the red blood cells with an inert gas as described with oxygen depleted refrigerated storage in U.S. Pat. No. 5,624,794 and U.S. Pat. No. 6,162,396. Preferred oxygen-free additive solutions comprise modifications of EAS61 (Hess et al., Transfusion 40: 1007-1011), and OFAS1 (U.S. Pat. No. 5,789,151). A preferred oxygen-free additive solution is OFAS3. The present invention extends the useful shelf life of refrigerated packed red blood cells from the current approximately 6 week limit to about 12 to about 20 weeks. BRIEF DESCRIPTION OF THE DRAWINGS [0013] [0013]FIG. 1 shows the effect of pH and oxygen depletion on cellular ATP levels of red blood cells in OFAS3. [0014] [0014]FIG. 2 shows the effect of pH and oxygen depletion on the percentage of red blood cells exposing phosphotidylserine in OFAS3. [0015] [0015]FIG. 3 shows the effect of pH and oxygen depletion on red blood cell hemolysis in OFAS3. [0016] [0016]FIG. 4 shows the effect on red blood cell ATP levels of metabolic supplements added at different pH's in the presence or absence of oxygen. [0017] [0017]FIG. 5 shows the effect on red blood cell 2,3-DPG levels of metabolic supplements added at different pH's in the presence or absence of oxygen. [0018] [0018]FIG. 6 shows the effect on the percentage of red blood cells exposing phosphotidylserine of addition of metabolic supplements at different pH's in the presence and absence of oxygen. [0019] [0019]FIG. 7 shows the effect on vesicle protein production of red blood cells of addition of metabolic supplements at different pH's in the presence or absence of oxygen. DETAILED DESCRIPTION OF THE INVENTION [0020] In its most general form, the present invention provides methods and compositions extending the useful shelf life of refrigerated red blood cells. The present invention more than doubles the useful shelf life of red blood cells and overcomes current limitations in the blood industry by providing longer and less perishable blood supplies. [0021] Metabolic supplementation is used commercially. For example, Rejuvesol is indicated for use at 37° C. and a 1 hour rejuvenation of stored blood just prior to transfusion or just prior to freezing in glycerol. The present invention describes addition of metabolic supplement during refrigerated storage combined with the use of oxygen free additive solution (i.e., OFAS3) and oxygen removal. With this approach, unprecedented results have been obtained. For example, red blood cell storage well beyond the current 6-week limit for 12 or up to 20 weeks at 4° C. with levels of 2-3 DPG and ATP that are above those found in freshly drawn blood. A rationale for this efficacy is suggested or inferred from the fact that in the cold, earlier enzymatic steps of the glycolytic pathway are more seriously impaired than the later enzymatic steps. Thus, by bypassing the earlier enzymatic steps of glycolysis with the addition of metabolic intermediates that directly feed or serve as substrates for the later enzymatic steps, we have been able to significantly boost the production of ATP and 2-3 DPG. The fact that these substrates readily traverse the erythrocyte membrane at cold temperature (i.e., 4° C.) is clearly demonstrated by the experimental results obtained which are presented herein. The use of Rejuvesol in its current formulation does incur the need for a simple wash step prior to transfusion. [0022] Metabolic supplementation of the invention is effected at least once, preferably during oxygen-depleted refrigerated storage (i.e., 4°) of red blood cells (c.f., U.S. Pat. Nos. 5,624,794; 6,162,396), along with oxygen-free additive solution, preferably OFAS3 or modification thereof. Blood units are not warmed. EAS61 and OFAS1 are additive solutions known in the art. [0023] Metabolic supplement is added to refrigerated red blood cells. A first addition is made within 6-10 weeks of storage. A second addition is optionally added within 11-20 weeks of storage. [0024] Metabolic supplement solution composition is presented in Table 1. TABLE 1 Concentration Ingredient (g/unit of addition) Na pyruvate 0.1-2.0 Inosine 0.5-3.0 Adenine 0.01-1.0  Na phosphate dibasic   0-2.0 Na phosphate monobasic   0-2.0 pH 5.5-8.0 [0025] The concentrations, given in mM units, of various blood additive solutions are presented in Table 2. TABLE 2 Ingredient AS-3 AS-1 OFAS1 EAS61 OFAS3 Adenine 2.2 2 2 2 2 Dextrose 61 122 110 110 110 Mannitol — 42 65 55 55 NaCl 70 154 — 26 26 Na citrate 20 — 20 13 — Citric acid 2 — — — — Na 2 HPO 4 — — — 12 12 NaH 2 PO 4 20 — 20 — — pH 7.2* 8.3 6.5* vol. added 200 250 200 200 (mL) final Hct ˜40 ˜35 ˜40 ˜40 [0026] Preferred concentration ranges of OFAS3 are presented in Table 3. TABLE 3 Ingredient Range (mM) Adenine 0.5-4.0 Dextrose  50-150 Mannitol 20-70 NaCl  0-100 NaH 2 PO 4  2-20 NH 4 Cl  0-30 pH 5.5-7.7 mL added 100-300 [0027] Final Hct 30-50 [0028] The following Examples are illustrative of the invention and are not intended to be limitative thereof. EXAMPLE 1 OFAS3: Effect of pH and Oxygen Depletion on Cellular ATP Levels [0029] Results of experimentation to determine the effect of pH and oxygen depletion on cellular ATP levels with blood samples containing oxygen-free additive solution (OFAS3) are presented in FIG. 1. Each point on the graph is the average of 6 subjects. For comparative purposes, AS1 and AS3, the current U.S. standard additive solution, serve as a control. There is a large variability in the values between different test subjects. In order to see the effect of pH, P values-(t-test for paired two samples for means) were calculated and are presented in Table 4. TABLE 3 Pairwise Test of ATP Values (For Oxygen Depleted Storage at Various pH's) Time P(T < = t) one-tail P(T < = t) one-tail (Days) pH 6.5 vs. pH 8.3 pH 6.5 vs. pH 7.4 9 0.002 0.007 13 0.032 0.327 20 0.008 0.116 28 0.001 0.104 41 0.072 0.072 49 0.023 0.111 66 0.008 0.149 83 0.007 0.147 99 0.008 0.388 [0030] Although there are large subject to subject variations in ATP levels, there are significant differences between pH 6.5 and pH 8.3. These data show that oxygen depletion further enhances ATP levels as much as 33% by week 3 and 38% by week 14. The increase in ATP levels is dramatically enhanced when red blood cells are stored in oxygen depleted conditions. The best result was obtained with additive solution (OFAS3) at pH 6.5 with oxygen depletion. EXAMPLE 2 OFAS3: Effect of pH and Oxygen Depletion on % of Cells Exposing Phosphotidylserine [0031] Results of experimentation to determine the effect of pH and oxygen depletion on the % of red blood cells exposing phosphotidylserine with samples containing oxygen-free additive solution (OFAS3) are presented in FIG. 2. Data were obtained by flow cytometer measurements using FITC-Annexin IV probe. Each point on the graph is the average of 6 subjects. There is a significant reduction in exposed phosphotidylserine after 10 weeks when pH 8.3 and pH 6.5 blood samples, both oxygen depleted, are compared. EXAMPLE 3 OFAS3: Effect of pH and Oxygen Depletion on Red Blood Cell Hemolysis [0032] Results of experimentation to determine the effect of pH and oxygen depletion on red blood cell hemolysis with blood samples containing oxygen-free additive solution (OFAS3) are presented in FIG. 3. Each point on the graph is the average of 6 subjects. Three different pH's were tested, pH 6.5, pH 7.4, and pH 8.3, with control cultures that were not oxygen-depleted. At week 16, the pH 6.5 oxygen-depleted refrigerated red blood cell storage system has the lowest extent of hemolysis. EXAMPLE 4 Addition of Metabolic Supplements During Refrigerated Oxygen-Depleted Red Blood Cell Storage: Effect of Metabolic Supplements Added at Different pH's in the Presence or Absence of Oxygen on Cellular ATP Levels [0033] Results of experimentation to determine the effect of addition of metabolic supplements added during refrigerated, oxygen-depleted storage of red blood cells at different pH's in the presence or absence of oxygen on cellular ATP levels, are graphically presented in FIG. 4. Two different pH's were tested, pH 6.5 and pH 8.3, with control cultures that are not oxygen depleted. Metabolic supplement, Rejuvesol, was added to cultures as indicated by the arrows in FIG. 4, which correspond approximately to additions during cold storage at 9, 14, and 21 weeks respectively. These data show that ATP levels are significantly increased each time the cold fuel/metabolic supplement is added. The highest ATP levels are sustained with pH 6.5 additive solution under oxygen depleted conditions. ATP levels are sustained near or above day 0 values throughout 22 weeks of storage with the additions of cold fuel. EXAMPLE 5 Addition of Metabolic Supplements During Refrigerated Oxygen-Depleted Red Blood Cell Storage: Effect of Metabolic Supplements Addition at different pH's in the Presence and Absence of Oxygen on Cellular 2,3-DPG Levels [0034] Results of experimentation to determine the effect of addition of metabolic supplements during refrigerated, oxygen-depleted red blood cell storage in the presence or absence of oxygen on cellular 2,3-DPG levels, are presented in FIG. 5. Each point on the graph is the average of 6 subjects. Two different pH's were evaluated, pH 6.5 and pH 8.3. Control cultures are not oxygen-depleted. Metabolic supplement, Rejuvesol, was added at the time indicated by the arrows, which correspond approximately to 8, 14, and 20 weeks respectively. These data show that oxygen depletion elevates 2,3-DPG levels significantly at the start of storage, without addition of metabolic supplements. Addition of metabolic supplements increases 2.3-DPG levels slowly at 4° C., and keeps these levels well above day 0 values, thus enhancing oxygen delivery capacity of the transfused blood. EXAMPLE 6 Addition of Metabolic Supplements During Refrigerated Oxygen-Depleted Red Blood Cell Storage: Effect of Metabolic Supplements Addition at different pH's in the Presence and Absence of Oxygen on the % of Red Blood Cells Exposing Phosphotidylserine [0035] Results of experimentation to determine the effect of addition of metabolic supplements during refrigerated, oxygen-depleted red blood cell storage in the presence or absence of oxygen on the percent of red blood cells exposing phosphotidylserine are presented in FIG. 6. Data were obtained from measurements by flow cytometer using FITC-Annexin IV probe. Each point on the graph represents the average of 6 subjects. Two different pH's were evaluated, pH 6.5 and pH 8.3, with metabolic supplement, Rejuvesol, added at the time indicted by the arrows which correspond to additions at approximately 8.6, 14, and 20 weeks. Control cultures are not oxygen-depleted. Phosphotidylserine is gradually exposed during refrigerated (4° C.). However, addition of metabolic supplements reverses this exposure. This experiment has been repeated three times with similar results. The lowest levels of exposure were seen with pH 6.5 storage buffer with oxygen depletion. EXAMPLE 7 Addition of Metabolic Supplements During Refrigerated Oxygen-Depleted Red Blood Cell Storage: Effect of Metabolic Supplements Addition at different pH's in the Presence and Absence of Oxygen on Vesicle Production [0036] Results of experimentation to determine the effect of addition of metabolic supplements during refrigerated, oxygen-depleted red blood cell storage in the presence or absence of oxygen on the vesicle production are presented in FIG. 7. Each point on the graph represents the average of 6 subjects. Two different pH's were evaluated, pH 6.5 and pH 8.3, with metabolic supplement, Rejuvesol, added at the time indicted by the arrows which correspond to additions at approximately 8.6, 14, and 20 weeks respectively. Control cultures are not oxygen-depleted. It is known that refrigerated red blood cells shed vesicles during storage. Addition of metabolic supplements slows vesicle production. In the system comprising metabolic supplementation during oxygen-depleted refrigerated storage with oxygen-free additive solution, the additive solution OFAS3 was shown to be the most effective of such additives. EXAMPLE 8 Twenty-Four-Hour In Vivo Post Transfusion Survival of Stored Red Cell Units [0037] Eight normal subjects each donated a unit of whole blood via a standard, manual method on two separate occasions approximately 8 weeks apart. Subject requirements were the same as those that apply for allogeneic blood donors as established by 21 CFR640.3 and the Standards of the American Association of Blood Banks. These units were processed via centrifugation to yield packed red cells via a “soft spin” technique (2000 g*3 min) following holding at room temperature for 1-2 hours, and 200 mL of an experimental additive solution OFAS3 were added (Table 2) to yield a final hematocrit of 35-45%. These and all other manipulations of units involving addition of solutions or sampling were accomplished via a sterile connection device. [0038] The test units were stored in an anaerobic environment following multiple flushes to minimize the oxygen content of each unit using highly purified Ar and H 2 Following completion of sampling, the test units were made anaerobic following the procedure provided by the sponsor. Briefly, the units were transferred to a 2000 mL transfer bag using the SCD. Sputtering grade argon was introduced into the unit via a 0.22 micron filter until the transfer bag was completely filled with gas/blood and rotated 10 min at room temperature. Following this hold period, the gas was expelled through the same 0.22 micron filter using a plasma expressor and a vacuum line. This procedure was repeated 6 times, and the unit was transferred to a standard PL146 red cell storage bag with an Ar flush. The unit was then placed in an anaerobic culture jar and 3 exchanges of the contents of the jar were performed with Ar, the last consisting of 2 parts Ar, 1 part scientific grade H 2 before the jar was placed in a monitored 4° C. refrigerator. When subsequent samples were taken via the SCD, the storage jar again underwent gas replacement prior to the unit being placed back in the refrigerator. Jars were flushed weekly with Ar if no sampling occurred in that week. Control units were stored in the same refrigerator without altering their gaseous environment. [0039] After 7 weeks of storage, test units underwent a metabolic supplementation using a licensed solution (Rejuvesol, Cytosol Laboratories, Braintree, Mass.); test units underwent an additional metabolic supplementation at 11 weeks (if recoveries to date indicated that continued storage was warranted, vida infra) The contents of the bottle of metabolic supplement were aspirated via needle and syringe and injected via a sampling port into a plastic transfer bag that had been previously flushed with Ar and to which had already been attached a 0.22 micron filter. The solution was then transferred to the unit by sterile docking, and the unit was promptly returned to refrigerated storage (without repeating the gas exchange procedure and without incubation or washing). [0040] Control units were utilized for radiolabeling and autologous reinfusion at 10 weeks; test units were continued in the protocol so long as the prior radiolabeled recovery suggested the continued viability of the cells. In addition, for a radiolabeled recovery to be conducted, the ATP must have been at least 50% of the Day 0 value, and the hemolysis must have been no more than 3.0% at the preceding sampling. [0041] Radiolabe]ing to allow for determination or in vivo red cell recovery’ was conducted according to published procedures [J. Nucl. Med. 1975; 16:435-7] 10-20 μCiNa 2 51 CrO 4 (Bracco, Princeton, N.J.) were added to a 10 mL aliquot of the unit's cells for 30 min. at room temperature followed by a single double-volume saline wash. [Blood 1871; 38:378-86; Transfusion 1984; 24:109-14] (Prior to labelling, cells from test units were washed four times with a double volume saline wash to remove remaining constituents of the rejuvenation solution.) These cells were injected simultaneously with fresh autologous red cells that had been labeled with 10-20 μCi 99m Tc pertechnetate after “tinning” to determine the subject's red cell volume; [Dave, R. J., Wallacae, M. e., eds. Diagnostic and investigational uses of radiolabeled blood elements. Arlington: American Association of Blood Banks, 1987] labeled cells were washed once with 40 mL ice-cold saline. Reinfusions were conducted promptly after labeling, and labeled cells were kept on ice until then, Samples were taken from 5 to 30 min. and then at 24 h to determine circulating radioactivity. Red cell volumes were determined by single and double label calculation methods after correction for counting interference and 99m Tc label elution prior to injection Results of a 24-hr in vivo post tranfusion survival study of stored red cell units are presented in Table 5. Hemolysis remained below 1% through 14 weeks of storage. The maximum noted was 1.75% at 16 weeks in one unit. TABLE 5 volunteer A B C D E F G n Average std dev single layer 10 wks test 73.9 74.2 69.6 72.5 64.6 81.9 90.3 7 75.3 8.4 12 wks test 69.9 66.9 71.6 74.3 78.05 84.6 6 74.2 6.3 14 wks test 65.6 61.7 58.3 79.6 74.2 78.8 6 69.7 9.1 16 wks test 69.7 75.1 2 72.4 3.8 10 wks control 71.7 78.5 66.6 56.8 77.6 73.8 78.0 7 71.9 7.9 double label 10 wks test 82.6 83.5 76.7 78.6 62.1 82.0 96.0 7 80.2 10.1 12 wks test 67.1 68.3 78.4 75.0 80.8 86.0 6 75.9 7.3 14 wks test 64.8 63.6 57.1 78.7 79.6 76.0 6 70.0 9.4 16 wks test 79.2 74.2 2 76.7 3.5 10 wks control 72.4 79.7 68.2 49.7 74.5 69.7 73.7 7 69.7 9.6 # At weeks 7 and 11, metabolic supplements were added at 4C. [0042] Although the present invention describes in detail certain embodiments, it is understood that variations and modifications exist known to those skilled in the art that are within the invention. Accordingly, the present invention is intended to encompass all such alternatives, modifications and variations that are within the scope of the invention as set forth in the following claims.

There is provided methods and compositions for the storage of red blood cells. The compositions are metabolic supplements which are preferably added to refrigerated red blood cells suspended in an additive solution. Red blood cells are preferably stored under conditions of oxygen-depletion. Metabolic compositions comprises pyruvate, inosine, adenine, and optionally dibasic sodium phosphate and/or monobasic sodium phosphate.

FIELD OF THE INVENTION The present invention pertains to a sewing device with a programmable electronic control system for sewing folds and tucks. BACKGROUND OF THE INVENTION In prior-art sewing devices of this type, the fabric being sewn is usually first delivered into a transfer position by a folding tool, which is provided on the front side with a replaceable guide tongue that is adapted to the course of the seam to be sewn where it is temporarily fixed in that position and subsequently held by a pressure pad by lowering this pressure pad. The feed of the fabric being sewn is subsequently performed by the pressure pad, which is displaced in the longitudinal direction as well as in the transverse direction and is likewise adapted in terms of its shape to the course of the seam. The sewing is performed along and as close to the pressure pad as possible, so that the pressure pad can be moved only away from the sewing needle to the outside during a transverse displacement movement. The drawback of these prior-art sewing devices is, among other things, that not only the corresponding seam program, but also the parts whose shape depends on the course of the particular seam (pressure pad and guide tongue) must be replaced when changing the desired course of the seam. In addition, additional mechanical settings must be performed in case of a change in the fabric thickness, because the distance between the sewing needle and the folded edge of the fabric depends on the fabric thickness in the prior-art devices. DE-GM 71 16 976 discloses a sewing device with a template rail driven in its longitudinal direction, which comprises a pressure pad for the fabric and a guide strip, which is continuously in contact with a guide means accommodated by a carrier in order to perform the movements which are directed sideways depending on the shape of the guide strip and which movements are superimposed to the longitudinal movement. Therefore, not only the corresponding seam program but also the parts whose shape depends on the course of the particular seam (guide strip) must be replaced in case of a change in the desired course of the seam in this prior-art device as well. This also applies to the sewing devices known from the documents DE 42 34 968 C1 and DE 40 31 200 A1 with a fabric holder driven in the longitudinal and transverse directions. These fabric holders, which are used to sew on pockets, have a sewing slot corresponding to the shape of the seam. Since the fabric holder grasps the pocket on both sides of the sewing slot it is carried without warping in unchanged aligned position in each transport direction. When preparing tucks, in which the seam always ends at an acute angle at the folded edge of the fabric, the edge must be exposed. It is therefore not possible to use fabric holders which surround the seam to be formed for holding and guiding fabric that is to be provided with tucks. Furthermore, a sewing unit for preparing tucks, which contains a folding tool movable between a receiving position and a transfer position for the fabric, an elastic folding aid plate, holding means in the form of a needle bar for the folded tuck, and a pressing rail for taking over the folded fabric and for guiding during the sewing operation, has been known from DE-PS 16 60 839. The angular position of the folding tool in relation to the pressing rail is adjustable in order to obtain a certain tuck depth. The folding tool pushes through the fabric during its forward movement under the elastic folding aid plate and the raised pressing rail to the extent that the tuck protrudes on the rear side of the pressing rail, doing so depending on the preselected angular position of the folding tool, i.e., corresponding to the desired tuck depth. At the end of the forward movement of the folding tool, the needle bar is moved downward, and its needles grasp the fabric in the area of the fold and fix it on a sewing table plate. However, this document contains no reference to any means that determine the end of the feed motion of the folding tool, whether, e.g., any stops or the end point of the feed path of the drive means for the folding tool. The accurate setting of the end of the feed motion is of great significance, because the intersection of the tuck seam with the folded edge of the fabric is determined by the position or the distance of the end point of the feed motion of the folding tool from the needle of the sewing machine. The desired high-quality sewing result is obtained only if the end stitches of the seam, which are shortened for the purpose of securing the seam, have the required distance from the folded edge of the fabric. If the distance is too great, the tuck forms a rather unattractive, funnel-shaped depression instead of a sharp tip. If, by contrast, the distance is too short, the length of the tuck will be too short and some of the shortened end stitches fall into the free area, as a consequence of which the seam will not be sufficiently secured. German patent application DE 100 11 162.9 discloses a sewing device with a sewing machine, a folding tool that can be moved between a receiving position and a transfer position for the fabric and a pressure pad for taking over the folded fabric and for guiding the fabric during the sewing operation, in sewing device stop means are provided for limiting the feed motion of the folding tool in the transfer position, and these stop means are located in the path of movement of the part of the folding edge of the folding tool that is surrounded by the folded fabric. It is achieved by means of the stop means arranged in this manner that the outside of the folded edge of the fabric will always have the same distance from the sewing needle in case of unchanged position of the stop means in case of thin and thick fabrics alike. However, regardless of the particular fabric thickness and without any corrective measures, the actual intersection, e.g., of a tuck seam, with the outside of the folded edge of the fabric always exactly coincides with the desired intersection. SUMMARY OF THE INVENTION The basic object of the present invention is to propose a sewing device of the type mentioned in the introduction, in which it is not necessary to change shape-dependent parts (guide tongue, pressure pad) in case of a change of the seam program and in which additional mechanical settings are not necessary despite a change in the fabric thickness. According to the invention, a sewing device is provided with a programmable electronic control system for sewing folds and tucks. The sewing device comprises a sewing machine with a sewing needle and with a holding-down device and with a folding tool. The folding tool can be moved between a receiving position and a transfer position for the fabric. A stop is provided for limiting the feed motion of the folding tool in the transfer position. A holder is provided for the fold or tuck formed. A pressure pad is provided for taking over the folded fabric in the transfer position and for guiding the fabric during the sewing operation. The pressure pad has a straight design independently from the seam format. To obtain a flat sewing field, the pressure pad is arranged movably in the longitudinal direction by a first drive connected to the control system and in the transverse direction by a second drive connected to the control system. The control system can be programmed such that the particular desired seam course can be obtained exclusively by the superimposition of the longitudinal and transverse movements of the pressure pad. Both movements away from the sewing needle and movements toward the sewing needle are possible. The holding-down device is designed as a floating foot that holds the fabric flat at least in the area of the sewing needle. The present invention is based on a device of the type described in DE 100 11 162.9 and it makes do without the use of a guide tongue that depends on the shape of the seam as well as of a shape-dependent pressure pad. The fabric is rather fed only with a folding tool with a straight folding edge and the fabric is held and guided during the sewing operation by means of a straight pressure pad, and the electronic control system is programmed such that the desired course of the seam is obtained exclusively by the superimposition of longitudinal and transverse movements of the pressure pad. To make it possible to sew the largest possible number of different seam courses with the sewing device according to the present invention, it proved to be advantageous not to sew directly at the pressure pad but to select a greater mean distance between the sewing needle and the pressure pad than in prior-art devices, so that the pressure pad can perform both movements to the outside and toward the sewing needle. To avoid the problems that can possibly occur during the pulling out of the sewing needle, a holding-down device designed as a floating foot, which is located at a short distance above the folded edge of the fabric and holds the fabric during the pulling out of the needle and during the tightening of the thread knot without otherwise touching it is arranged in the area of the sewing needle. To substantially shorten the changeover times of the sewing device even further during a change of the seam program, provisions are made in a preferred embodiment of the present invention for the seam parameters to be programmable in a graphics-supported manner. The sewing device contains for this purpose a display screen, which is electrically connected to the control system and on which the particular desired geometric seam course can be displayed. In addition, preferably standard seam programs are stored in the control system. In case of a change of a seam program, the particular new seam program is called up by depressing a corresponding key and the course of the seam is displayed on the display screen. If parameters of the seam program are to be changed, the corresponding new parameters are entered via a keyboard connected to the control system. All parameters of a seam course are defined now as length measurements. To prevent the fabric from bulging out in the axial and radial directions, it proved to be advantageous for the floating foot to have both an opening, wedge-shaped course on its side facing the folded edge of the fabric and a course decreasing obliquely to the folded edge of the fabric on its front side opposite the direction of movement of the fabric. In another embodiment of the present invention, the holding-down device is not fastened on the sewing machine of the sewing device according to the present invention, but on a part that also participates in the transverse movements of the pressure pad. The roller carrier of the drive displacing the pressure pad at right angles to the longitudinal direction has proved to be particularly suitable as such a part. Due to the joint movement of the holding-down device in the transverse direction, it can be designed as a holding-down device having such a large area that it covers the fabric area between the pressure pad and the edge of the fabric during the entire sewing operation and holds it flat as a result. Bulges which may frequently occur in the case of a holding-down device fastened to the sewing machine especially near the end of the given sewing operation due to the great distance existing between the holding-down device and the pressure pad are therefore eliminated in this case. Provisions are made in another embodiment of the present invention for arranging a pressing finger, whose underside is flush with the underside of the pressure pad and which is offset transversely, at the pressure pad for the distortion-free transport of the fabric. The pressing finger preferably has a wedge-shaped cross section, so that the holding-down device seated on the pressing finger at the beginning of the sewing operation slides off from the pressing finger without a jerk as the sewing progresses. Further details and advantages of the present invention appear from the following exemplary embodiments explained on the basis of figures. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a perspective view of a sewing device according to the present invention with a sewing machine, on which a holding-down device is fastened, and with a keyboard and display screen unit. FIG. 2 is an enlarged view of the sewing device shown in FIG. 1 in the area of the holding-down device with the fabric indicated by broken line; FIG. 3 is a top view of the holding-down device shown in FIG. 2; FIG. 4 is a side view of the holding-down device shown in FIG. 2; FIG. 5 is a schematic block diagram of the electronic control system with the keyboard and display screen unit connected; FIG. 6 is a front view of the keyboard and display screen unit with a graphically displayed seam program; FIG. 7 is a view of a standard seam program on the display screen; FIG. 8 is a view of another standard seam program on the display screen; FIG. 9 is a view of another standard seam program on the display screen; FIG. 10 is a view of another standard seam program on the display screen; FIG. 11 is a perspective view of a second exemplary embodiment of the sewing device according to the present invention; FIG. 12 is an enlarged perspective view of the drives of the pressure pad of the sewing device shown in FIG. 11 with the pressure pad and the holding-down device; FIG. 13 is a top view of the drive arrangement shown in FIG. 12 in a lateral position of the pressure pad: FIG. 14 is another top view of the drive arrangement shown in FIG. 12 in another lateral position of the pressure pad; FIG. 15 is a section through the arrangement shown in FIG. 13 along the section line indicated by line XV—XV there. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in particular, a sewing device for sewing folds and tucks with an electric sewing machine 3 arranged on a table 2 and with a programmable electronic control system 4 is designated by 1 in FIG. 1 . Furthermore, a folding tool 5 with straight folding edge 6 , which is arranged displaceably from a receiving position into a transfer position for the fabric, is arranged at the table 2 . Furthermore, a straight pressure pad 7 for holding and guiding the fabric during the sewing operation, which can be moved in the longitudinal and transverse directions by means of corresponding drives 8 , 9 , is located at the table 2 . The sewing device 1 also includes a holding means 10 with stop means for limiting the feed motion of the folding tool 5 in the transfer position and for the temporary fixation of the fabric provided with the fold as well as a display screen-keyboard unit 12 arranged on a swivel arm 11 . The electric sewing machine 3 , the display screen-keyboard unit 12 , the drives 8 , 9 for the pressure pad 7 as well as the drives 13 , 14 for the holding means 10 and the folding tool 5 are electrically connected to the control system 4 (FIG. 5 ). The design of the display screen-keyboard unit 12 is shown in FIG. 6 . The keys shown are so-called soft keys. A holding-down device 16 designed as a floating foot, whose connection to the sewing machine 3 is not shown specifically for clarity's sake, is fastened to the sewing machine 3 in the area of the sewing needle 15 , which is indicated by a dash-dotted line only (FIG. 2 ). To prevent bulges of the fabric 17 indicated by broken line from being formed during sewing in the axial and radial directions, the floating foot 16 has both an oblique course decreasing to the folded edge 19 of the fabric on its front side 18 located opposite the direction of movement of the fabric 17 (FIG. 3) and an opening, wedge-shaped course on its side 20 facing the folded edge 19 of the fabric 17 (FIG. 4 ). The mode of operation of the sewing device according to the present invention will be explained in greater detail below. Regardless of the desired course of the seam, the fabric is first displaced in the known manner from a receiving position into a transfer position while forming the desired fold by means of the folding tool 5 and is fixed in that position by means of the holding means 10 by lowering holding needles. The folding tool 5 subsequently moves back into its receiving position. The pressure pad 7 lowers onto the fabric and now holds the fabric, while the holding needles are displaced upward and release the fabric. The desired seam program (e.g., for a tuck) can now be set unless it had been set already. To do so, e.g., the seam course shown in FIG. 7, which is designated by 25 , is set. This seam course will then appear graphically on the display screen 21 of the display screen-keyboard unit 12 . By depressing the number keys 22 , the parameters of the course of the seam can be changed. The variable values are the tuck depth 1 ′, the tuck length 2 ′ and the curvature 3 ′. In addition, more values such as the program number, the stitch length, seam additions, etc., can be entered by means of the keyboard and displayed on the display screen 21 . After depressing the “enter” key 23 , the programmed values are taken over into a corresponding memory 24 of the control system 4 (FIG. 5) and the sewing operation is initiated. After the conclusion of the sewing operation, the pressure pad 7 releases the fabric 17 and returns into its starting position, so that a new fabric can be fed in by means of the folding tool 5 . It was found that the majority of the tucks and pleats occurring in practice can be programmed with the four basic forms shown in FIGS. 7-10. FIG. 8 shows the seam course 26 of another tuck. The variable values are the tuck depth 1 ″, the tuck length 2 ″, the waist depth 3 ″, the waist length 4 ″, the first curvature 5 ″, and the second curvature 6 ″ in this case. FIG. 9 shows the seam course 27 of a pleat with variable first pleat depth 1 ′″, the pleat length 2 ′″, the second pleat depth 3 ′″, and the curvature 4 ′″. FIG. 10 also shows the seam course 28 of a pleat with variable first pleat depth 1 IV , a first pleat length 2 IV , a second pleat depth 3 IV , a second pleat length 4 IV , a third pleat depth 5 IV , a first curvature 6 IV , and a second curvature 7 IV . After entering all the values intended for the given seam course the control system performs a plausibility check of the data. Should they lead to an unacceptable seam, the value entered incorrectly is displayed on the display screen-keyboard unit 12 . Other, unusual seam forms can be obtained by free programming. Any desired seam course is possible in the sewing field in which the sewing device can move (e.g., 250×30 mm). The present invention is by no means limited to the above-described exemplary embodiment. For example, FIGS. 11-15 show an exemplary embodiment in which a holding-down device 30 that is fastened to a roller carrier 31 rather than to the sewing machine 3 is provided. This roller carrier in turn guides the pressure pad designated by 7 and is connected to the second drive 9 , so that it participates in the transverse movements of the pressure pad 7 . Due to this joint movement of the holding-down device 30 in the transverse direction, it can have such a large area that it covers the sewing field 32 between the pressure pad 7 and the folded edge 19 of the fabric 17 (FIG. 13) during the entire sewing operation and holds it flat as a result. The effect caused by the longitudinal movement of the pressure pad 7 , according to which a moment that facilitates the upward bulging of the fabric acts in the fabric, is therefore considerably less noticeable in the case of the large-area holding-down device 30 than in case of the use of the holding-down device 16 described in connection with FIGS. 1 and 2. The corresponding arrangement of the holding-down device 30 at the roller carrier 31 appears especially from FIG. 12 . The pressure pad 7 is arranged laterally pivotably around an axis of rotation 34 that is displaceable in the longitudinal direction by the drive 8 , and the lateral pivoting movement takes place by means of the second drive 9 to obtain the flat sewing field 32 (FIG. 13 ). This drive 9 acts via the roller carrier 31 with the rollers 35 on the pressure pad 7 , which is guided between the rollers 35 in the longitudinal direction, on the one hand, and can be pivoted at right angles to the longitudinal direction, on the other hand. The special effect visible in FIG. 14 that the very small distance existing between the pressure pad 7 and the holding-down device 30 at the beginning of the sewing operation increases markedly in the course of the sewing operation because of the different radial distances R 1 and R 2 between the axis of rotation 34 , on the one hand, and the rollers 35 , on the other hand, but without appreciably exposing the corresponding area of the fabric, arises in conjunction with the rotatably movable mounting of the pressure pad. In the same manner as in the case of the holding-down device 16 shown in FIGS. 1 and 2, the increase in the distance generates a pulling force directed at right angles. Even though this pulling force is markedly weaker than that occurring in case of the use of the holding-down device 16 , it is nevertheless capable of exerting a noticeable smoothing effect, because the bulges of the fabric are considerably flatter under the holding-down device 30 than are the bulges that can be formed between the holding-down device 16 and the pressure pad 7 . A transversely projecting, relatively short pressing finger 36 , whose underside is flush with the underside of the pressure pad 7 , makes a further contribution to the distortion-free transport of the fabric. As is apparent from FIG. 13, the pressure pad 7 and the pressing finger 36 surround the sewing field 32 in an L-shaped manner. The pressing finger 36 has a wedge-shaped cross section (FIG. 15 ). As a result, the holding-down device 30 seated on the pressing finger 36 at the beginning of the sewing operation can slide off from the pressing finger 36 without a jerk as the sewing progresses. While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

A sewing device ( 1 ) is provided with a programmable electronic control system ( 4 ) for sewing folds and tucks. Such that format-dependent parts (guide tongue, pressure pad) can be eliminated at the time of a change of the seam program the use of a guide tongue is eliminated that depends on the form of the seam and of a format-dependent pressure pad. The feed of the fabric is performed only with a folding tool ( 5 ) with straight folding edge and the holding and guiding of the fabric during the sewing operation using a straight pressure pad ( 7 ). The electronic control system ( 4 ) can be programmed such that the desired seam course is obtained exclusively by the superimposition of longitudinal and transverse movements of the pressure pad ( 7 ). Parameters ( 1′-7 IV ) that determine the seam course are preferably entered in a graphics-supported manner.

This is a 371 of PCT/CH98/0012, filed Mar. 23, 1998. The Swiss priority documents, application numbers CH 1997 Jul. 18, 1997, CH 1997 Jul. 19, 1997, and CH 1997 Jul. 20, 1997, are still pending. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler or water heater equipped with a burner, including a housing surrounding a boiler compartment, a cylindrical heat exchanger, which divides the boiler compartment into a combustion chamber, and an exhaust chamber; whereby said heat exchanger comprises passages distributed across its surface for the hot exhaust gas, and a burner head positioned in the combustion chamber. 2. Review of the Prior Art Such a boiler or water heater is disclosed in the French Patent document No. 93 00498, and is incorporated herein by reference. It contains a number of boiler designs, which exhibit the above-mentioned design features. These boilers are designed to accommodate gas burners and comprise a cylindrical casing with the sides closed off, and a plurality of flame openings distributed across the surface area. Such a gas-fired boiler or water heater is space-saving in its design and does not require a separate furnace room. It has been a long-standing desire for such a space-saving furnace to be capable of being operated with fuel oil. The disadvantage of using gas as fuel is the more complex fuel storage requirements as compared to oil. As a result, the gas furnace has to rely on either an expensive pressurized tank or on a connection to a gas distribution network. Oil, on the other hand, has been stored in sufficient quantities in tanks located at the site of the furnace in thousands of installations without any problems. Additionally, the supply and filling of the tanks with oil is substantially simpler and less dangerous as compared to gas. It is therefore the purpose of the invention to provide a furnace, which can be operated by an oil burner without making it larger than a comparable gas furnace. Furthermore, the furnace should be capable to be operated with a gas or an oil burner. Additionally, it is an objective of this invention to provide a furnace characterized by low exhaust emissions, reduced heat loss, and low noise levels. SUMMARY OF THE INVENTION The objectives are met, in accordance to the intent of this invention, by adding a fire tube comprising an axial flame opening and a flame deflection piece positioned at a distance to the flame opening to the burner head; whereby, the fire tube is designed in such as manner that the flame between the fire tube and the heat exchanger is deflected. One of the advantages of a furnace designed per this invention is that it can be operated by burners, which produce a lance-shaped flame. Such a flame usually requires a very long combustion chamber. A flame deflection piece, designed in accordance to this invention, allows the length of the combustion chamber to be significantly reduced. The deflection piece turns the flame back to its origin and, as a result, reduces the length of the combustion chamber by ½. This allows the combustion chamber to be almost fully saturated by the flame exiting the fire tube which is subsequently being deflected into the opposite direction. The deflection of the flame to its origin has the further advantage that very hot gas is present around the fire tube very soon after the flame is initiated, enhancing the cold start characteristics of the furnace. Another advantage of deflecting the flame in the above-described manner lies in the fact that the combustion chamber can be utilized much more effectively and, therefore, can be designed in a more compact fashion as compared to those systems that produce a long, thin flame. More specifically, because of the burner head being surrounded by the flame, the entire length of the combustion chamber is more thermally uniform and therefore better-suited to exchange heat energy to the heat exchange medium. It is advisable for the heat exchanger to comprise a blocking plate, which effectively limits the combustion system in lengthwise direction. In addition to the exhaust chamber, this creates an additional chamber into which exhaust gas flows from the exhaust chamber. The exhaust gas is cooled by the heat exchanger and is partially re-circulated back to the fire tube in order to cool the flame, and partially exhausted through the flue. A preferred blocking plate design separates the discharge chamber from the boiler compartment at its side facing away from the combustion chamber, whereby said discharge chamber is connected to the flue. Such a discharge chamber resides axially inside the boiler. This allows a uniform flow of the exhaust gas from peripheral the areas into the discharge chamber. This avoids non-uniform thermal loading issues of the heat exchanger. It is preferred for the blocking plate to separate a re-circulation chamber from the boiler compartment. Cooled exhaust gas can then re-circulate through this re-circulation chamber into the fire tube in order to cool the flame. The re-circulation chamber can also serve the function of a discharge chamber. It would be preferred, if the discharge chamber and/ or re-circulation chamber (separated by the blocking plate) were surrounded by the heat exchanger. This allows additional cooling of the exhaust gas entering these chambers prior to leaving the furnace. As a result of the dual contact with the heat exchanger, the exhaust gas is cooled to approximately 80 degrees C., at continuous operation under full load. This allows for the exhaust gas to be piped directly into a flue (made of a plastic compound) upon exiting the boiler. Further, it would be preferred that the blocking plate between the combustion chamber and the exhaust discharge chamber is shaped in a curved manner in such a way as to allow an increase in the length of the combustion chamber while minimizing the space requirements of the exhaust discharge chamber. Such a design feature results in a relatively large ratio of the heat exchanger surface surrounding the exhaust discharge chamber with respect to its volume. In order to reduce the number of required parts, the flame deflection piece should form the blocking plate. In doing so, the position of the deflection piece in relation to the housing wall has certain acoustic advantages. The domed surface should point towards the exhaust discharge chamber. The purpose of this domed surface is to deflect the flame without the participation of any heat exchange elements, permitting the use of the entire heat exchange area since the deflection piece does not obstruct any passages for the hot exhaust gas. A preferred flame deflector design comprises a flame separator, positioned along the centerline of the flame and a ring-shaped deflector dish, which surrounds the flame separator. The flame separator divides the flame, and the deflector dish reflects the flame in order to change the flame direction by 180 degrees. The deflector dish should be made circumferentially uniform in order for the flame to retain a uniform shape after its deflection. The casing of the heat exchanger consists of pipes positioned adjacent to one another with clearance between the pipes; whereby, said pipes are positioned to surround the combustion chamber and are connected to a supply and a return line. The heat exchange pipes should be wound in a screw-like manner. Such a heat exchanger unit is easy to manufacture; it comprises a large surface area and provides for passages between the pipes. Additionally, pipes can be made to thinner wall thicknesses as compared to castings, and therefore offer a more dynamic heat transfer characteristic which is reflected by higher performance at reduced space requirements. It would also be beneficial if this heat exchanger were assembled from a plurality of heat exchanger units. The individual heat exchanger units have the advantage of using shorter pipe lengths, as compared to a single unit having one long pipe system, resulting in higher through-flow velocities. The heat exchanger units should be connected to the supply and return in parallel. Heat exchanger units using individual elements disclosed in the French Patent No. 93 00498 are applied successfully. The units described in said documents are characterized by a flat cross-sectional area of the pipes, resulting in an increase in the heat exchange area compared to typical pipes with round cross-sectional areas. Furthermore, an essential advantage of these heat exchanger units is due to the fact that these units are in series production for gas furnaces, and are therefore readily available in the marketplace at excellent quality levels. The burner should be equipped with exhaust gas re-circulation in order to exceed the current regulated emission values, especially during cold starts. Even if gas burners are applied to the boiler described by this invention, it is still preferred to use oil burners, simply because oil can be stored in inexpensive tanks, which can be readily refilled. The dependence on a supply distribution network can thus be avoided. Furthermore, the handling of oil is much less hazardous as compared to the handling of gas, which must be stored under pressure in appropriate tanks, in cases where it is not supplied through a gas distribution network. It would be of benefit, however, to have the capability of the burner to operate on both fuels, oil as well as gas. If the burner head is designed to accommodate oil as well as gas, both fuels can be used in the same furnace alternatively with only minimal effort. This has the advantage that price changes and supply shortages can be dealt with in a more proactive fashion, or in a case of having to wait for a hook-up to be in place to provide gas to the furnace, oil can be used as a temporary means to power the furnace until the gas supply is secured. For oil operation, an injector sprays oil into the exhaust gas being re-circulated into the fire tube; the inlet openings into the fire tube for fresh air as well as exhaust are designed so that fresh air and exhaust are mixed together inside the hollow cylinder or the hollow truncated cone making up the turbulent zone. As the oil mixes with the exhaust, it fully evaporates prior to its mixing with air. This assures very low exhaust emission values and an excellent starting behavior of the burner. For gas operation, an air supply passage is used for introducing the gaseous fuel. The inlet openings into the fire tube for the fuel/air mixture and the re-circulated exhaust gas, respectively, are designed so that fuel/fresh air mixture and the exhaust are mixed together inside the hollow cylinder or the hollow truncated cone making up the turbulent zone. Because of these similar methods of introducing the fuels, the same fire tube can be applied to both fuels, gas and oil. It is feasible, to leave the oil injector in place during gas operation and to leave the gas supply system in place during oil operation, in order to provide a dual-fuel furnace with a single burner. A system, such as the one described above, is capable of achieving exhaust emission values of below 60 mg Nox per KW when operating on oil and under 20 mg Nox per KW when operating on gas. The CO values also lie under 20 mg Nox per KW at a very low level. In addition to these very low emission levels, the furnace is capable of performing very well under cold start conditions. In the combustion chamber, in the area between the fire tube or deflected flame and the heat exchanger, resides a cylindrical combustion chamber shroud, comprising openings for the hot combustion gas. This combustion chamber shroud provides a uniform distribution of the hot combustion gas to the heat exchanger and also serves as an ash collector. It protects the heat exchanger from direct contact with the flame. This allows the distance between the flame and the heat exchanger to be very small. Additionally, this combustion chamber shroud has a positive influence in terms of noise suppression. The openings are arranged so that the combustion gas exits the combustion chamber shroud tangentially in order to facilitate the flow of the gas through the heat exchanger casing to also occur in a tangential direction. This improves the heat transfer as compared to a system that utilizes a radial through-flow direction. The housing of this unit should be proportioned to be similar in size of a wall heating unit or a “plug-in” kitchen unit. The housing, including the air supply line and exhaust line, should have a length of approximately 50 cm. A short design should be able to operate with a boiler length of 30 cm. This means that a separate room for this furnace is not required. It can be stored in a cabinet. The air supply line should surround the exhaust gas line in a counter-flow arrangement in order to pre-heat the incoming air by the warm exhaust gas. The blower should be placed next to the housing with the air supply line leading from the blower to the end face of the housing and the burner head, in order to minimize the length and depth of the unit. It is practical to line the end faces of the combustion chamber with fireproof tiles with a labyrinth-like inner structure. These protect the underlying metal pats, isolate tho housing from the heat of the flame, and dampen the sound emissions of the burner. It is furthermore appropriate to provide one end face of the housing with a removable cover. It would be advantageous to mount the burner on this cover because this allows easy access to the boiler compartment and the burner. It is further advisable to use authentic stainless steel, which resists the aggressive exhaust gas and condensates. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of reference to the drawings, where: FIG. 1 . 1 - 1 . 4 shows schematically four arrangements of boilers; FIG. 2 shows a longitudinal cross-sectional view, of the boiler according to the preferred embodiment of the invention; FIG. 3 shows a longitudinal cross-sectional view, of the boiler with a combustion chamber shroud according to the preferred embodiment of the invention; FIG. 4 shows a cross-sectional view of the embodiment according to FIG. 3; FIG. 5 shows a longitudinal cross-sectional view of an oil burner head according to the preferred embodiment of the invention; FIG. 6 shows a schematic view of the combustion process using liquid fuel; FIG. 7 shows a top view of a panel insert with guide plates cut out but not twisted; FIG. 8 shows a cross-section through a panel insert according to FIG. 7; whereby, the guide plates are twisted for swirl generation; and FIG. 9 shows a longitudinal cross-section of the gas burner head and schematic of combustion process using gaseous fuel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1.1 depicts schematically a simplified illustration of a boiler 11 ′ in accordance to this invention. Housing 13 is divided by heat exchanger 15 into a combustion chamber 17 and an exhaust chamber 19 . Fire tube 23 is positioned at one of the end faces of the combustion chamber 17 ; flame 25 exits the fire tube axially. Fresh air flows through the mixing pipe 21 into the fire tube 23 , leading to combustion in flame 25 and subsequently flows as hot combustion gas through the passages in heat exchanger 15 into the exhaust chamber 19 (arrows). From there, the combustion gas exits the exhaust chamber 19 through an opening not shown in FIG. 1) in housing 13 . FIG. 1.2 illustrates a design variation, whereby, a blocking plate 27 limits the length of the combustion chamber 17 in boiler 11 ″. The boiler compartment is thereby divided into 3 zones: The combustion chamber 17 , the exhaust chamber 19 and an exhaust discharge chamber 29 . The exhaust gas now flows from the exhaust chamber first through the heat exchanger 15 into the exhaust discharge chamber 29 , and from there, through an opening 31 into the flue. FIG. 1.3 depicts a simplified version of the FIG. 1.2; here, the heat exchanger 15 does not separate the exhaust chamber 19 from the exhaust discharge chamber 29 , but simply surrounds the combustion chamber 17 . Arrows in FIGS. 1.2 and 1 . 3 indicate how the exhaust gas is being re-circulated into the fire tube 23 . FIG. 1.4 displays a boiler 11 ″″ in whose boiler compartment an additional blocking plate 27 ′ is added to blocking plate 27 . This additional blocking plate creates a recirculation chamber 33 . The re-circulating exhaust gas from combustion chamber 17 reaches the re-circulation chamber 33 after having traversed through heat exchanger 15 , the exhaust chamber 19 , and, again, through the heat exchanger 15 . Once there, it is being drawn into the fire tube 23 through its re-circulation openings. FIG. 2 displays via a cross-sectional view through an embodiment of boiler 11 including the heat exchanger 15 , the combustion chamber 17 , and the exhaust chamber 19 . Combustion chamber 17 contains fire tube 23 , which comprises re-circulation openings 35 and one flame opening 37 . The heat exchanger 15 consists of pipes 40 with a flat cross-sectional area, which are wound in a screw-like manner. The pipes 40 are positioned at a distance from one another, so that exhaust gas can flow through the gaps 41 between the pipes 40 of the heat exchanger 15 . The heat exchanger 15 consists of individual elements 43 , which are connected in series and/or parallel to a supply and a return line, respectively. Opposing the flame opening is a deflector piece 39 . This deflector piece 39 forms a blocking plate 27 or is connected to a blocking plate 27 . The blocking plate 27 is positioned between two pipes 40 or between two elements 43 , so that the hot exhaust gas is forced to flow from the combustion chamber 17 through the gaps 41 into the exhaust chamber 19 and from there, once again through the pipes 40 into the exhaust discharge chamber 29 . The exhaust gas can then finally exit the exhaust discharge chamber 29 via a passage 31 into the flue or into an exhaust pipe. The deflection piece 39 comprises an elevated area 47 on axis 45 of the fire tube 23 or boiler 11 , which is facing the flame and symmetrically separates the flame. The flame is subsequently re-directed into a direction, opposite its original direction and impacts in the area between the fire tube 23 and the heat exchanger tubes 40 against the root of the flame. This effect creates an approximately cylindrical flame body equal to approximately twice the fire tube diameter. The hot exhaust gas exits through the gaps 41 between the pipes 40 throughout the length of the combustion chamber 17 , causing an energy exchange with the exchange medium flowing through the pipes 40 . The deflector piece 39 exhibits a dish-like shape and is positioned with its floor near the end face of housing 13 , which is positioned opposite to the fire tube. The inner diameter 51 connects with the outer diameter 53 of the dish-shaped deflector 49 ; whereby, the surface created by 51 and 53 seats flush against the heat exchange pipes 40 . Surface 55 of the deflector piece runs from the inner diameter 51 away from the heat exchange pipes in a slanted fashion, so that none of the pipes 40 are obstructed by the depth occupied by the deflector piece 39 , thereby allowing passage of the exhaust gas. The space occupied by the dish-shaped deflector piece 39 goes on the expense of the exhaust discharge chamber 29 , which, as a result, is reduced to the minimum required. Because of the shape of blocking plate 27 , the combustion chamber 17 increases in length towards the exhaust discharge chamber 29 . This allows the length of the boiler to be reduced to a minimum. On the side of the boiler 11 that houses the burner head resides cover 57 , which is bolted against housing 13 . Cover 57 comprises an opening 59 on whose inside resides a panel or baffle plate 61 , onto which the fire tube 23 is mounted. A ring-shaped disk 63 is positioned at a distance around the fire tube 23 . This disk is made of fireproof, porous, or felt-like material and because of its insulating properties, tends to reduce heat loss and noise emissions. The deflector piece 39 has the same structure and, therefore, the same effect. The fire tube 23 comprises re-circulation openings 35 located near the baffle plate 61 , through which exhaust gas is being circulated into the fire tube from the area 65 between the heat exchanger 15 and fire tube 23 . The exhaust envelops an air stream, which is being centrally admitted into fire tube 23 . This causes the fire tube to be surrounded by hot exhaust gas upon ignition of a flame and therefore heats up rapidly. An oil injector 67 is provided for liquid fuel operation, which sprays the fuel through the centered airflow into the shroud-like exhaust flow enveloping the airflow. The fuel evaporates within the exhaust flow. The evaporated fuel mixes with the air and exhaust in a turbulent fashion. The flame burns in blue color since all the fuel is converted into gaseous fuel prior to the generation of a flame. The same burner head can be used for operation with gas. However, the gaseous fuel should be introduced into the low-pressure side of the air blower. A shroud of exhaust, having been re-circulated through the recirculation openings 35 into fire tube 23 , envelops the incoming air/fuel stream, mixes with said air/fuel stream in the swirl zone between the shroud and core flow and, as a result, the flame burns very similar to the flame generated by the evaporated liquid fuel. The fire tube 23 becomes hot with both fuels and transfers a certain amount of energy onto the heat exchanger 15 through radiation. This effect is desired, especially since blue flames have relatively little radiation energy. Exhaust emission values are very low with both fuels. Nox emissions are under 60 mg Nox per KW when operating on oil and below 20 mg Nox per KW when operating on gas. The CO values also lie under 16 mg Nox per KW at a very low level. Burners that are built and functioning per the above-described methodology are described in detail in the submitted European notifications “process and devices for combusting liquid fuel” and “process and devices for combusting gaseous fuel”, both of which are based the Swiss priority notifications No. 1997 Jul. 18, 1997 and Jul. 19, 1997, respectively. FIGS. 3 and 4 illustrate an additional embodiment of a boiler in accordance to this invention. FIG. 3 depicts a longitudinal cross-section of a boiler; FIG. 4 depicts a cross-section in the transverse direction of the same boiler. In this boiler 11 , the blocking plate is designed as a simple deflector plate without a specific form. A further substantive difference relative to the boiler 11 shown in FIG. 2 is the presence of a combustion chamber shroud 69 in combustion chamber 17 on the burner side of heat exchanger 15 . The combustion chamber shroud 69 comprises slots 71 on its cylindrical outer surface, as well as guide plates 73 , which serve to release the hot exhaust gas from the inner area of the combustion chamber 17 and to guide the gas by means of a rotating flow field around axis 45 through the gaps 41 located between the pipes 40 of the heat exchanger 15 (ref. Arrows in FIG. 4 ). The flame is reflected back to the end face of housing 13 near the fire tube via the area between fire tube 23 and the combustion chamber shroud 69 . The combustion chamber shroud directs the exhaust gas into a spiraling motion. The bottom area 75 of the combustion chamber shroud contains a zone without any slots 71 . This allows any ash present on the combustion chamber shroud to collect at the bottom 75 for easy removal. The combustion chamber shroud 69 also serves as protection for the heat exchanger 15 as it keeps it from direct contact with the flames. The combustion chamber shroud is therefore closed at the front of the shroud, near the blocking plate 27 or the deflector piece 39 and has no slots 71 , through which a partially reflected flame could potentially reach the pipes 40 of the heat exchanger 15 . The screw-like windings 77 of the heat exchanger 15 are connected with a straight connecting piece 79 (FIG. 4) to a supply line 81 and return line 83 . The individual heat exchanger units 43 consist of four windings of pipe 40 having a flat cross-sectional flow area and are connected in parallel to the supply line 81 and the return line 83 . Local enlargements of the pipe walls (not shown) maintain a distance between the pipes 40 of the windings 77 . FIG. 5 displays a burner head 111 for liquid fuels, including baffle plate 113 , which can be mounted on a wall surface (not shown) of combustion chamber 112 . Fire tube 115 is mounted on the baffle plate in direction of the flow (indicated by arrow 114 ); whereby, said fire tube has a diameter to length ratio of approximately 1:2. In addition, a fuel injector 119 is positioned along the centerline 117 of the fire tube. The devices used to mount the fuel injector and the baffle plate 113 form together a panel insert, as described in document No. EPA 0 650 014. The fuel injector head 123 seats centrally in panel insert 125 . The spray opening 121 of fuel injector 119 lies in the plane of the baffle plate 113 and the panel insert, respectively. Panel insert 125 is mounted on the baffle plate and covers the opening 127 of the baffle plate 113 but leaves a ring-shaped air vent 129 around the fuel injector head 123 open. This ring-shaped air vent 129 occupies an area of approximately 8% of the cross-sectional area of the fire tube 115 . Air vent 129 is furthermore equipped with swirl generating guide plates 131 . These guide plates 131 are positioned radially and are slanted relative to the centerline 117 of fire tube and the direction of flow 114 , so that air flowing through air vent 129 is energized into a rotary motion around centerline 117 . The guide plates 131 are manufactured from one piece together with the panel insert 125 (FIG. 7 and FIG. 8 ). The guide plates are cut or stamped from the panel insert 134 and subsequently twisted by 60 to 80 degrees relative to the mounting surface. In doing so, round cut-outs are added in the area of the metal that receive most of the deformation as a result of the twisting action, in order to prevent the initiation of cracks (ref. 136 in FIG. 7 ). Fire tube 115 is mounted on the baffle plate 113 by means of connecting tabs 133 . These connecting tabs 133 are formed as a single unit with the wall surface 139 of fire tube 115 , protrude above the end of fire tube 15 facing the baffle plate and are inserted through slots in the baffle plate 113 . On the upstream side of the baffle plate 113 , the connecting tabs are twisted upon insertion so that a tight connection between the baffle plate 113 and fire tube 115 is established. The connecting tabs 133 are shaped in step-like manner, becoming smaller towards the end. The steps 137 in the tab contact the baffle plate 113 on the side of the fire tube and define the opening width of the recirculation slots. Exhaust gas is being drawn through this re-circulating slot 135 , along the baffle plate 113 and the panel insert 125 into the fire tube 115 in order to avoid soot in this area. A favorable opening width is approximately 1 mm. The fire tube 115 comprises recirculation openings 139 near the baffle plate, through which exhaust gas is being drawn, primarily due to the sub-atmospheric pressure which is generated downstream of the baffle plate 113 as a result of the present air flow. In the case being described, there are 18 circular recirculation openings 139 , each with a diameter of 6 mm. The openings 139 can be lower or higher in number and/or can also be shaped differently. The fire tube 115 comprises an inner tube diameter of approximately 80 mm and a length of 160 mm. The end of the fire tube 15 facing the combustion chamber 112 is narrowed. This contraction 141 reduces the flame exit area 143 relative to the fire tube cross-sectional area. The outer area of 145 of the fire tube 115 is rounded off towards the inside in order to create the contraction 141 . The spark electrodes 147 are inserted through the baffle plate 13 near the periphery of the fire tube 115 with insulating elements 149 and protrude with their ends 151 into the fire tube 115 . The point 153 at which the spark is generated is placed at a distance from the baffle plate 113 equal to approximately ⅖ of the length of fire tube 115 . FIG. 6 displays the various zones during combustion schematically. Because of air being forced through the air opening 129 , a sub-atmospheric pressure is being generated in area 161 , downstream of the baffle plate 113 . Through this sub-atmospheric pressure, exhaust gas is being drawn into the combustion zone as indicated by the arrows 163 and 165 . The exhaust gas forms a shroud 167 around the core of flow 169 . The exhaust gas entering along arrow 165 moves along the outer surface of the baffle plate and thus protects it from carbon deposits. Regions of turbulences 171 are being generated in the area between the core flow 169 and the exhaust shroud 167 , which facilitate mixing of the two mediums, air and exhaust. The fuel is introduced into the airflow along the shortest way possible, as depicted by the dashed lines 172 . The conical shroud of the spray plume comprises an angle of between 60 and 90 degrees. The fuel injector should preferably be designed to provide a spray plume angle of 80 degrees. The fuel evaporates in the area 173 of exhaust shroud 167 and mixes inside the exhaust shroud with the exhaust gas by means of the turbulences 175 generated in this area. Since there is no fuel present upstream of the evaporation zone 173 that could ignite, and because of the short distance that the fuel has to travel through the airflow 169 , practically all of the fuel is evaporated in the exhaust shroud 167 by the time it comes in contact with fresh air to initiate combustion. Evaporated fuel is mixed with the exhaust gas and air inside the turbulences 171 and combustion initiates only in the area of said turbulences 171 with only minimal emissions. The flame begins to develop in its root area 177 , approximately at the end of the first third of fire tube 115 . The flame root is embedded in the shape of a ring in the area between the exhaust shroud 167 and air stream 169 . The center air stream 171 terminates near the last third of the fire tube and serves to cool the tube. The thickness of the exhaust shroud 167 is decreasing as it traverses downstream, while the exhaust/fuel mixture mixes with air along the same distance. The fuel vapor is being supplied to the flame over a distance of approximately two thirds of the length of the fire tube. Thus, the flame has a ring-shaped, long-drawn root region and is being fed by shroud 167 . Because of the contraction 141 of the fire tube, shroud zone 167 is limited in the downstream direction. The gas in the shroud region 167 is impeded while exiting the fire tube, which favors a mixing of the two media. Inside the fire tube, the exiting flame remains stable. FIG. 9 illustrates schematically burner head 111 ′ for operation with gas and the different zones present during combustion of gaseous fuel. Burner head 111 ′ corresponds, in essence, to burner head 111 for liquid fuels. However, a perforated plate 157 is positioned downstream in front of the baffle plate 113 and a distance to said baffle plate 113 . The perforated plate 157 comprises an opening 158 through which the oil injector 119 penetrates. Several holes are placed around this area which serve to create a pressure loss designed to avoid a blow-back of the flames into the supply passage 155 . A fuel supply line 190 and a blower 192 are attached to the supply passage. Since the air/fuel mixture is forced through passage 129 , a sub-atmospheric pressure is created in area 161 , downstream of the baffle plate 113 . Because of this sub-atmospheric pressure, exhaust gas is being drawn into this area, as indicated by arrows 163 and 165 . The exhaust gas forms a shroud 167 around the core flow 169 . The exhaust gas entering along arrow 165 flows along the surface of the baffle plate, which serves to protect it from excessive carbon or soot deposits. Turbulence is generated between the core flow 169 and shroud 167 within which the two media air/fuel and exhaust are being mixed. Gaseous fuel is mixed with air and exhaust gas inside the turbulence 171 , and combustion initiates only in the region of said turbulence 171 with only minimal emissions. The flame begins to develop in its root area 177 , approximately at the end of the first third of fire tube 115 . The flame root is embedded in the shape of a ring in the area between the exhaust shroud 167 and air stream 169 . The center air stream 171 terminates near the last third of the fire tube and helps cool the tube. The thickness of the exhaust shroud 167 is decreasing as it traverses downstream, while the exhaust/fuel mixture mixes with air along the same distance. The flame bums steadily with only minimal emissions. The gas burner, designed in accordance to the intent of this invention, functions practically independently of the form or shape of the combustion chamber. It is especially suited for compact furnace designs with relatively short combustion chambers. The burner is not only suitable for burning gas. By replacing item 119 by a fuel injector that is appropriate for liquid fuels with the capability of generating a conical shroud spray pattern, the burner is then suitable for the combustion of heating oil extra light, “Eco-oil” or kerosene. With liquid fuels, the burner achieves exhaust emission values for Nox of less than 60 mg/KW.

This invention concerns a boiler fitted with a burner suitable for wall heaters or built-in kitchen heaters in which a mantle-shaped heat exchanger made of pipe elements connected in parallel and/or series divides the boiler chamber into a combustion chamber and an exhaust chamber. The heat exchanger has openings for hot flue gases distributed over its mantle. The burner head disposed in the combustion chamber is suitable for burning oil and has a flame tube with an axial flame opening and a flame baffle element disposed at a distance from the flame opening which is constructed so that the flame is diverted into the space between the flame tube and the heat exchanger. In addition, a fire chamber mantle can be disposed between the heat exchanger and the flame tube to protect the heat exchanger from direct contact with the flame.